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-rw-r--r--gc/README.md37
-rw-r--r--gc/default/default.c9832
-rw-r--r--gc/default/extconf.rb5
-rw-r--r--gc/extconf_base.rb14
-rw-r--r--gc/gc.h291
-rw-r--r--gc/gc_impl.h127
-rw-r--r--gc/mmtk/.gitignore1
-rw-r--r--gc/mmtk/Cargo.lock1108
-rw-r--r--gc/mmtk/Cargo.toml42
-rw-r--r--gc/mmtk/cbindgen.toml36
-rw-r--r--gc/mmtk/depend18
-rw-r--r--gc/mmtk/extconf.rb24
-rw-r--r--gc/mmtk/mmtk.c1655
-rw-r--r--gc/mmtk/mmtk.h175
-rw-r--r--gc/mmtk/src/abi.rs335
-rw-r--r--gc/mmtk/src/active_plan.rs56
-rw-r--r--gc/mmtk/src/api.rs551
-rw-r--r--gc/mmtk/src/binding.rs129
-rw-r--r--gc/mmtk/src/collection.rs122
-rw-r--r--gc/mmtk/src/heap/cpu_heap_trigger.rs370
-rw-r--r--gc/mmtk/src/heap/mod.rs9
-rw-r--r--gc/mmtk/src/heap/ruby_heap_trigger.rs105
-rw-r--r--gc/mmtk/src/lib.rs161
-rw-r--r--gc/mmtk/src/object_model.rs124
-rw-r--r--gc/mmtk/src/pinning_registry.rs187
-rw-r--r--gc/mmtk/src/reference_glue.rs26
-rw-r--r--gc/mmtk/src/scanning.rs291
-rw-r--r--gc/mmtk/src/utils.rs161
-rw-r--r--gc/mmtk/src/weak_proc.rs328
-rw-r--r--gc/wbcheck/extconf.rb3
-rw-r--r--gc/wbcheck/wbcheck.c1936
31 files changed, 18259 insertions, 0 deletions
diff --git a/gc/README.md b/gc/README.md
new file mode 100644
index 0000000000..cb71357973
--- /dev/null
+++ b/gc/README.md
@@ -0,0 +1,37 @@
+# Ruby's Garbage Collectors
+
+This directory contains implementations for Ruby's garbage collector (GC). The GC implementations use the Modular GC API to interact with Ruby. For more details about this API, see the [Modular GC API](#modular-gc-api) section.
+
+Two GC implementations are included in Ruby:
+
+- Default: The GC implementation that is used by default in Ruby. This GC is stable and production ready. The implementation uses a mark-sweep-compact algorithm.
+- MMTk: An experimental implementation using the [MMTk](https://www.mmtk.io/) framework. The code lives in the [ruby/mmtk](https://github.com/ruby/mmtk) repository and is synchronized here. MMTk provides a [wide variety of GC algorithms](https://www.mmtk.io/status#implemented-collectors) to choose from. For usage instructions and current progress, refer to the [ruby/mmtk](https://github.com/ruby/mmtk) repository.
+
+## Building guide
+
+> [!TIP]
+> If you are not sure how to build Ruby, follow the [Building Ruby](https://docs.ruby-lang.org/en/master/contributing/building_ruby_md.html) guide.
+
+> [!IMPORTANT]
+> Ruby's modular GC feature is experimental and subject to change. There may be bugs or performance impacts. Use at your own risk.
+
+### Building Ruby with Modular GC
+
+1. Configure Ruby with the `--with-modular-gc=<dir>` option, where `dir` is the directory you want to place the built GC libraries into.
+2. Build Ruby as usual.
+
+### Building GC implementations shipped with Ruby
+
+1. Build your desired GC implementation with `make install-modular-gc MODULAR_GC=<impl>`. This will build the GC implementation and place the built library into the `dir` specified in step 1. `impl` can be one of:
+ - `default`: The default GC that Ruby ships with.
+ - `mmtk`: The GC that uses [MMTk](https://www.mmtk.io/) as the back-end. See Ruby-specific details in the [ruby/mmtk](https://github.com/ruby/mmtk) repository.
+2. Run your desired GC implementation by setting the `RUBY_GC_LIBRARY=<lib>` environment variable, where `lib` could be `default`, `mmtk`, or your own implementation (as long as you place it in the `dir` specified in step 1).
+
+## Modular GC API
+
+> [!WARNING]
+> The Modular GC API is experimental and subject to change without notice.
+
+GC implementations interact with Ruby via the Modular GC API. All implementations must provide the functions in [gc/gc_impl.h](https://github.com/ruby/ruby/blob/master/gc/gc_impl.h) for Ruby to hook into. GC implementations can use any public C API in Ruby, along with additional APIs defined in [gc/gc.h](https://github.com/ruby/ruby/blob/master/gc/gc.h).
+
+Additionally, create an extconf.rb file to build the GC library. This file must use [gc/extconf_base.rb](https://github.com/ruby/ruby/blob/master/gc/extconf_base.rb) and the `create_gc_makefile` method.
diff --git a/gc/default/default.c b/gc/default/default.c
new file mode 100644
index 0000000000..291ff91b81
--- /dev/null
+++ b/gc/default/default.c
@@ -0,0 +1,9832 @@
+#include "ruby/internal/config.h"
+
+#include <signal.h>
+
+#ifndef _WIN32
+# include <sys/mman.h>
+# include <unistd.h>
+# ifdef HAVE_SYS_PRCTL_H
+# include <sys/prctl.h>
+# endif
+#endif
+
+#if !defined(PAGE_SIZE) && defined(HAVE_SYS_USER_H)
+/* LIST_HEAD conflicts with sys/queue.h on macOS */
+# include <sys/user.h>
+#endif
+
+#ifdef BUILDING_MODULAR_GC
+# define nlz_int64(x) (x == 0 ? 64 : (unsigned int)__builtin_clzll((unsigned long long)x))
+#else
+# include "internal/bits.h"
+#endif
+
+#include "ruby/ruby.h"
+#include "ruby/atomic.h"
+#include "ruby_atomic.h"
+#include "ruby/debug.h"
+#include "ruby/thread.h"
+#include "ruby/util.h"
+#include "ruby/vm.h"
+#include "ruby/internal/encoding/string.h"
+#include "ccan/list/list.h"
+#include "darray.h"
+#include "gc/gc.h"
+#include "gc/gc_impl.h"
+
+#ifndef BUILDING_MODULAR_GC
+# include "probes.h"
+#endif
+
+#ifdef BUILDING_MODULAR_GC
+# define RB_DEBUG_COUNTER_INC(_name) ((void)0)
+# define RB_DEBUG_COUNTER_INC_IF(_name, cond) (!!(cond))
+#else
+# include "debug_counter.h"
+#endif
+
+#ifdef BUILDING_MODULAR_GC
+# define rb_asan_poison_object(obj) ((void)(obj))
+# define rb_asan_unpoison_object(obj, newobj_p) ((void)(obj), (void)(newobj_p))
+# define asan_unpoisoning_object(obj) if ((obj) || true)
+# define asan_poison_memory_region(ptr, size) ((void)(ptr), (void)(size))
+# define asan_unpoison_memory_region(ptr, size, malloc_p) ((void)(ptr), (size), (malloc_p))
+# define asan_unpoisoning_memory_region(ptr, size) if ((ptr) || (size) || true)
+
+# define VALGRIND_MAKE_MEM_DEFINED(ptr, size) ((void)(ptr), (void)(size))
+# define VALGRIND_MAKE_MEM_UNDEFINED(ptr, size) ((void)(ptr), (void)(size))
+#else
+# include "internal/sanitizers.h"
+#endif
+
+/* MALLOC_HEADERS_BEGIN */
+#ifndef HAVE_MALLOC_USABLE_SIZE
+# ifdef _WIN32
+# define HAVE_MALLOC_USABLE_SIZE
+# define malloc_usable_size(a) _msize(a)
+# elif defined HAVE_MALLOC_SIZE
+# define HAVE_MALLOC_USABLE_SIZE
+# define malloc_usable_size(a) malloc_size(a)
+# endif
+#endif
+
+#ifdef HAVE_MALLOC_USABLE_SIZE
+# ifdef RUBY_ALTERNATIVE_MALLOC_HEADER
+/* Alternative malloc header is included in ruby/missing.h */
+# elif defined(HAVE_MALLOC_H)
+# include <malloc.h>
+# elif defined(HAVE_MALLOC_NP_H)
+# include <malloc_np.h>
+# elif defined(HAVE_MALLOC_MALLOC_H)
+# include <malloc/malloc.h>
+# endif
+#endif
+
+#ifdef HAVE_MALLOC_TRIM
+# include <malloc.h>
+
+# ifdef __EMSCRIPTEN__
+/* malloc_trim is defined in emscripten/emmalloc.h on emscripten. */
+# include <emscripten/emmalloc.h>
+# endif
+#endif
+
+#ifdef HAVE_MACH_TASK_EXCEPTION_PORTS
+# include <mach/task.h>
+# include <mach/mach_init.h>
+# include <mach/mach_port.h>
+#endif
+
+#ifndef RUBY_DEBUG_LOG
+# define RUBY_DEBUG_LOG(...)
+#endif
+
+#ifndef GC_HEAP_INIT_BYTES
+#define GC_HEAP_INIT_BYTES (2560 * 1024)
+#endif
+#ifndef GC_HEAP_FREE_SLOTS
+#define GC_HEAP_FREE_SLOTS 4096
+#endif
+#ifndef GC_HEAP_GROWTH_FACTOR
+#define GC_HEAP_GROWTH_FACTOR 1.8
+#endif
+#ifndef GC_HEAP_GROWTH_MAX_BYTES
+#define GC_HEAP_GROWTH_MAX_BYTES 0 /* 0 is disable */
+#endif
+#ifndef GC_HEAP_REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO
+# define GC_HEAP_REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO 0.01
+#endif
+#ifndef GC_HEAP_OLDOBJECT_LIMIT_FACTOR
+#define GC_HEAP_OLDOBJECT_LIMIT_FACTOR 2.0
+#endif
+
+#ifndef GC_HEAP_FREE_SLOTS_MIN_RATIO
+#define GC_HEAP_FREE_SLOTS_MIN_RATIO 0.20
+#endif
+#ifndef GC_HEAP_FREE_SLOTS_GOAL_RATIO
+#define GC_HEAP_FREE_SLOTS_GOAL_RATIO 0.40
+#endif
+#ifndef GC_HEAP_FREE_SLOTS_MAX_RATIO
+#define GC_HEAP_FREE_SLOTS_MAX_RATIO 0.65
+#endif
+
+#ifndef GC_MALLOC_LIMIT_MIN
+#define GC_MALLOC_LIMIT_MIN (16 * 1024 * 1024 /* 16MB */)
+#endif
+#ifndef GC_MALLOC_LIMIT_MAX
+#define GC_MALLOC_LIMIT_MAX (32 * 1024 * 1024 /* 32MB */)
+#endif
+#ifndef GC_MALLOC_LIMIT_GROWTH_FACTOR
+#define GC_MALLOC_LIMIT_GROWTH_FACTOR 1.4
+#endif
+
+#ifndef GC_OLDMALLOC_LIMIT_MIN
+#define GC_OLDMALLOC_LIMIT_MIN (16 * 1024 * 1024 /* 16MB */)
+#endif
+#ifndef GC_OLDMALLOC_LIMIT_GROWTH_FACTOR
+#define GC_OLDMALLOC_LIMIT_GROWTH_FACTOR 1.2
+#endif
+#ifndef GC_OLDMALLOC_LIMIT_MAX
+#define GC_OLDMALLOC_LIMIT_MAX (128 * 1024 * 1024 /* 128MB */)
+#endif
+
+#ifndef GC_MALLOC_INCREASE_LOCAL_THRESHOLD
+#define GC_MALLOC_INCREASE_LOCAL_THRESHOLD (8 * 1024 /* 8KB */)
+#endif
+
+#ifdef RB_THREAD_LOCAL_SPECIFIER
+#define USE_MALLOC_INCREASE_LOCAL 1
+static RB_THREAD_LOCAL_SPECIFIER int malloc_increase_local;
+#else
+#define USE_MALLOC_INCREASE_LOCAL 0
+#endif
+
+#ifndef GC_CAN_COMPILE_COMPACTION
+#if defined(__wasi__) /* WebAssembly doesn't support signals */
+# define GC_CAN_COMPILE_COMPACTION 0
+#else
+# define GC_CAN_COMPILE_COMPACTION 1
+#endif
+#endif
+
+#ifndef PRINT_ENTER_EXIT_TICK
+# define PRINT_ENTER_EXIT_TICK 0
+#endif
+#ifndef PRINT_ROOT_TICKS
+#define PRINT_ROOT_TICKS 0
+#endif
+
+#define USE_TICK_T (PRINT_ENTER_EXIT_TICK || PRINT_ROOT_TICKS)
+
+#ifndef HEAP_COUNT
+# if SIZEOF_VALUE >= 8
+# define HEAP_COUNT 12
+# else
+# define HEAP_COUNT 5
+# endif
+#endif
+
+/* The reciprocal table and pool_slot_sizes array are both generated from this
+ * single definition, so they can never get out of sync. */
+#if SIZEOF_VALUE >= 8
+# define EACH_POOL_SLOT_SIZE(SLOT) \
+ SLOT(32) SLOT(40) SLOT(64) SLOT(80) SLOT(96) SLOT(128) \
+ SLOT(160) SLOT(256) SLOT(512) SLOT(640) SLOT(768) SLOT(1024)
+#else
+# define EACH_POOL_SLOT_SIZE(SLOT) \
+ SLOT(32) SLOT(64) SLOT(128) SLOT(256) SLOT(512)
+#endif
+
+typedef struct ractor_newobj_heap_cache {
+ struct free_slot *freelist;
+ struct heap_page *using_page;
+ size_t allocated_objects_count;
+} rb_ractor_newobj_heap_cache_t;
+
+typedef struct ractor_newobj_cache {
+ size_t incremental_mark_step_allocated_slots;
+ rb_ractor_newobj_heap_cache_t heap_caches[HEAP_COUNT];
+} rb_ractor_newobj_cache_t;
+
+typedef struct {
+ size_t heap_init_bytes;
+ size_t heap_free_slots;
+ double growth_factor;
+ size_t growth_max_bytes;
+
+ double heap_free_slots_min_ratio;
+ double heap_free_slots_goal_ratio;
+ double heap_free_slots_max_ratio;
+ double uncollectible_wb_unprotected_objects_limit_ratio;
+ double oldobject_limit_factor;
+
+ size_t malloc_limit_min;
+ size_t malloc_limit_max;
+ double malloc_limit_growth_factor;
+
+ size_t oldmalloc_limit_min;
+ size_t oldmalloc_limit_max;
+ double oldmalloc_limit_growth_factor;
+} ruby_gc_params_t;
+
+static ruby_gc_params_t gc_params = {
+ GC_HEAP_INIT_BYTES,
+ GC_HEAP_FREE_SLOTS,
+ GC_HEAP_GROWTH_FACTOR,
+ GC_HEAP_GROWTH_MAX_BYTES,
+
+ GC_HEAP_FREE_SLOTS_MIN_RATIO,
+ GC_HEAP_FREE_SLOTS_GOAL_RATIO,
+ GC_HEAP_FREE_SLOTS_MAX_RATIO,
+ GC_HEAP_REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO,
+ GC_HEAP_OLDOBJECT_LIMIT_FACTOR,
+
+ GC_MALLOC_LIMIT_MIN,
+ GC_MALLOC_LIMIT_MAX,
+ GC_MALLOC_LIMIT_GROWTH_FACTOR,
+
+ GC_OLDMALLOC_LIMIT_MIN,
+ GC_OLDMALLOC_LIMIT_MAX,
+ GC_OLDMALLOC_LIMIT_GROWTH_FACTOR,
+};
+
+/* GC_DEBUG:
+ * enable to embed GC debugging information.
+ */
+#ifndef GC_DEBUG
+#define GC_DEBUG 0
+#endif
+
+/* RGENGC_DEBUG:
+ * 1: basic information
+ * 2: remember set operation
+ * 3: mark
+ * 4:
+ * 5: sweep
+ */
+#ifndef RGENGC_DEBUG
+#ifdef RUBY_DEVEL
+#define RGENGC_DEBUG -1
+#else
+#define RGENGC_DEBUG 0
+#endif
+#endif
+#if RGENGC_DEBUG < 0 && !defined(_MSC_VER)
+# define RGENGC_DEBUG_ENABLED(level) (-(RGENGC_DEBUG) >= (level) && ruby_rgengc_debug >= (level))
+#elif defined(HAVE_VA_ARGS_MACRO)
+# define RGENGC_DEBUG_ENABLED(level) ((RGENGC_DEBUG) >= (level))
+#else
+# define RGENGC_DEBUG_ENABLED(level) 0
+#endif
+int ruby_rgengc_debug;
+
+/* RGENGC_PROFILE
+ * 0: disable RGenGC profiling
+ * 1: enable profiling for basic information
+ * 2: enable profiling for each types
+ */
+#ifndef RGENGC_PROFILE
+# define RGENGC_PROFILE 0
+#endif
+
+/* RGENGC_ESTIMATE_OLDMALLOC
+ * Enable/disable to estimate increase size of malloc'ed size by old objects.
+ * If estimation exceeds threshold, then will invoke full GC.
+ * 0: disable estimation.
+ * 1: enable estimation.
+ */
+#ifndef RGENGC_ESTIMATE_OLDMALLOC
+# define RGENGC_ESTIMATE_OLDMALLOC 1
+#endif
+
+#ifndef GC_PROFILE_MORE_DETAIL
+# define GC_PROFILE_MORE_DETAIL 0
+#endif
+#ifndef GC_PROFILE_DETAIL_MEMORY
+# define GC_PROFILE_DETAIL_MEMORY 0
+#endif
+#ifndef GC_ENABLE_LAZY_SWEEP
+# define GC_ENABLE_LAZY_SWEEP 1
+#endif
+
+#ifndef VERIFY_FREE_SIZE
+#if RUBY_DEBUG
+#define VERIFY_FREE_SIZE 1
+#else
+#define VERIFY_FREE_SIZE 0
+#endif
+#endif
+
+#if VERIFY_FREE_SIZE
+#undef CALC_EXACT_MALLOC_SIZE
+#define CALC_EXACT_MALLOC_SIZE 1
+#endif
+
+#ifndef CALC_EXACT_MALLOC_SIZE
+# define CALC_EXACT_MALLOC_SIZE 0
+#endif
+
+#if defined(HAVE_MALLOC_USABLE_SIZE) || CALC_EXACT_MALLOC_SIZE > 0
+# ifndef MALLOC_ALLOCATED_SIZE
+# define MALLOC_ALLOCATED_SIZE 0
+# endif
+#else
+# define MALLOC_ALLOCATED_SIZE 0
+#endif
+#ifndef MALLOC_ALLOCATED_SIZE_CHECK
+# define MALLOC_ALLOCATED_SIZE_CHECK 0
+#endif
+
+#ifndef GC_DEBUG_STRESS_TO_CLASS
+# define GC_DEBUG_STRESS_TO_CLASS RUBY_DEBUG
+#endif
+
+typedef enum {
+ GPR_FLAG_NONE = 0x000,
+ /* major reason */
+ GPR_FLAG_MAJOR_BY_NOFREE = 0x001,
+ GPR_FLAG_MAJOR_BY_OLDGEN = 0x002,
+ GPR_FLAG_MAJOR_BY_SHADY = 0x004,
+ GPR_FLAG_MAJOR_BY_FORCE = 0x008,
+#if RGENGC_ESTIMATE_OLDMALLOC
+ GPR_FLAG_MAJOR_BY_OLDMALLOC = 0x020,
+#endif
+ GPR_FLAG_MAJOR_MASK = 0x0ff,
+
+ /* gc reason */
+ GPR_FLAG_NEWOBJ = 0x100,
+ GPR_FLAG_MALLOC = 0x200,
+ GPR_FLAG_METHOD = 0x400,
+ GPR_FLAG_CAPI = 0x800,
+ GPR_FLAG_STRESS = 0x1000,
+
+ /* others */
+ GPR_FLAG_IMMEDIATE_SWEEP = 0x2000,
+ GPR_FLAG_HAVE_FINALIZE = 0x4000,
+ GPR_FLAG_IMMEDIATE_MARK = 0x8000,
+ GPR_FLAG_FULL_MARK = 0x10000,
+ GPR_FLAG_COMPACT = 0x20000,
+
+ GPR_DEFAULT_REASON =
+ (GPR_FLAG_FULL_MARK | GPR_FLAG_IMMEDIATE_MARK |
+ GPR_FLAG_IMMEDIATE_SWEEP | GPR_FLAG_CAPI),
+} gc_profile_record_flag;
+
+typedef struct gc_profile_record {
+ unsigned int flags;
+
+ double gc_time;
+ double gc_invoke_time;
+
+ size_t heap_total_objects;
+ size_t heap_use_size;
+ size_t heap_total_size;
+ size_t moved_objects;
+
+#if GC_PROFILE_MORE_DETAIL
+ double gc_mark_time;
+ double gc_sweep_time;
+
+ size_t heap_use_pages;
+ size_t heap_live_objects;
+ size_t heap_free_objects;
+
+ size_t allocate_increase;
+ size_t allocate_limit;
+
+ double prepare_time;
+ size_t removing_objects;
+ size_t empty_objects;
+#if GC_PROFILE_DETAIL_MEMORY
+ long maxrss;
+ long minflt;
+ long majflt;
+#endif
+#endif
+#if MALLOC_ALLOCATED_SIZE
+ size_t allocated_size;
+#endif
+
+#if RGENGC_PROFILE > 0
+ size_t old_objects;
+ size_t remembered_normal_objects;
+ size_t remembered_shady_objects;
+#endif
+} gc_profile_record;
+
+struct RMoved {
+ VALUE flags;
+ VALUE dummy;
+ VALUE destination;
+};
+
+#define RMOVED(obj) ((struct RMoved *)(obj))
+
+typedef uintptr_t bits_t;
+enum {
+ BITS_SIZE = sizeof(bits_t),
+ BITS_BITLENGTH = ( BITS_SIZE * CHAR_BIT )
+};
+
+struct heap_page_header {
+ struct heap_page *page;
+};
+
+struct heap_page_body {
+ struct heap_page_header header;
+ /* char gap[]; */
+ /* RVALUE values[]; */
+};
+
+#define STACK_CHUNK_SIZE 500
+
+typedef struct stack_chunk {
+ VALUE data[STACK_CHUNK_SIZE];
+ struct stack_chunk *next;
+} stack_chunk_t;
+
+typedef struct mark_stack {
+ stack_chunk_t *chunk;
+ stack_chunk_t *cache;
+ int index;
+ int limit;
+ size_t cache_size;
+ size_t unused_cache_size;
+} mark_stack_t;
+
+typedef int (*gc_compact_compare_func)(const void *l, const void *r, void *d);
+
+typedef struct rb_heap_struct {
+ short slot_size;
+
+ /* Basic statistics */
+ size_t total_allocated_pages;
+ size_t force_major_gc_count;
+ size_t force_incremental_marking_finish_count;
+ size_t total_allocated_objects;
+ size_t total_freed_objects;
+ size_t final_slots_count;
+
+ /* Sweeping statistics */
+ size_t freed_slots;
+ size_t empty_slots;
+
+ struct heap_page *free_pages;
+ struct ccan_list_head pages;
+ struct heap_page *sweeping_page; /* iterator for .pages */
+ struct heap_page *compact_cursor;
+ uintptr_t compact_cursor_index;
+ struct heap_page *pooled_pages;
+ size_t total_pages; /* total page count in a heap */
+ size_t total_slots; /* total slot count */
+
+} rb_heap_t;
+
+enum {
+ gc_stress_no_major,
+ gc_stress_no_immediate_sweep,
+ gc_stress_full_mark_after_malloc,
+ gc_stress_max
+};
+
+enum gc_mode {
+ gc_mode_none,
+ gc_mode_marking,
+ gc_mode_sweeping,
+ gc_mode_compacting,
+};
+
+typedef rbimpl_atomic_uint64_t gc_counter_t;
+
+#if !defined(HAVE_GCC_ATOMIC_BUILTINS_64) && !defined(_WIN32) && \
+ !(defined(__sun) && defined(HAVE_ATOMIC_H) && (defined(_LP64) || defined(_I32LPx)))
+# define MALLOC_COUNTERS_NEED_LOCK 1
+#endif
+
+struct gc_malloc_bytes {
+ gc_counter_t malloc;
+ gc_counter_t free;
+
+ /* Snapshots of `malloc` / `free` taken at the end of the last GC */
+ gc_counter_t malloc_at_last_gc;
+ gc_counter_t free_at_last_gc;
+};
+
+typedef struct rb_objspace {
+ struct {
+ struct gc_malloc_bytes counters;
+#if RGENGC_ESTIMATE_OLDMALLOC
+ struct gc_malloc_bytes oldcounters;
+#endif
+#ifdef MALLOC_COUNTERS_NEED_LOCK
+ rb_nativethread_lock_t lock;
+#endif
+ } malloc_counters;
+
+ struct {
+ size_t limit;
+#if MALLOC_ALLOCATED_SIZE
+ size_t allocated_size;
+ size_t allocations;
+#endif
+ } malloc_params;
+
+ struct rb_gc_config {
+ bool full_mark;
+ } gc_config;
+
+ struct {
+ unsigned int mode : 2;
+ unsigned int immediate_sweep : 1;
+ unsigned int dont_gc : 1;
+ unsigned int dont_incremental : 1;
+ unsigned int during_gc : 1;
+ unsigned int during_compacting : 1;
+ unsigned int during_reference_updating : 1;
+ unsigned int gc_stressful: 1;
+ unsigned int during_minor_gc : 1;
+ unsigned int during_incremental_marking : 1;
+ unsigned int measure_gc : 1;
+ } flags;
+
+ rb_event_flag_t hook_events;
+
+ rb_heap_t heaps[HEAP_COUNT];
+ size_t empty_pages_count;
+ struct heap_page *empty_pages;
+
+ struct {
+ rb_atomic_t finalizing;
+ } atomic_flags;
+
+ mark_stack_t mark_stack;
+ size_t marked_slots;
+
+ struct {
+ rb_darray(struct heap_page *) sorted;
+
+ size_t allocated_pages;
+ size_t freed_pages;
+ uintptr_t range[2];
+ size_t freeable_pages;
+
+ size_t allocatable_bytes;
+
+ /* final */
+ VALUE deferred_final;
+ } heap_pages;
+
+ st_table *finalizer_table;
+
+ struct {
+ int run;
+ unsigned int latest_gc_info;
+ gc_profile_record *records;
+ gc_profile_record *current_record;
+ size_t next_index;
+ size_t size;
+
+#if GC_PROFILE_MORE_DETAIL
+ double prepare_time;
+#endif
+ double invoke_time;
+
+ size_t minor_gc_count;
+ size_t major_gc_count;
+ size_t compact_count;
+ size_t read_barrier_faults;
+#if RGENGC_PROFILE > 0
+ size_t total_generated_normal_object_count;
+ size_t total_generated_shady_object_count;
+ size_t total_shade_operation_count;
+ size_t total_promoted_count;
+ size_t total_remembered_normal_object_count;
+ size_t total_remembered_shady_object_count;
+
+#if RGENGC_PROFILE >= 2
+ size_t generated_normal_object_count_types[RUBY_T_MASK];
+ size_t generated_shady_object_count_types[RUBY_T_MASK];
+ size_t shade_operation_count_types[RUBY_T_MASK];
+ size_t promoted_types[RUBY_T_MASK];
+ size_t remembered_normal_object_count_types[RUBY_T_MASK];
+ size_t remembered_shady_object_count_types[RUBY_T_MASK];
+#endif
+#endif /* RGENGC_PROFILE */
+
+ /* temporary profiling space */
+ double gc_sweep_start_time;
+ size_t total_allocated_objects_at_gc_start;
+ size_t heap_used_at_gc_start;
+ size_t heap_total_slots_at_gc_start;
+
+ /* basic statistics */
+ size_t count;
+ unsigned long long marking_time_ns;
+ struct timespec marking_start_time;
+ unsigned long long sweeping_time_ns;
+ struct timespec sweeping_start_time;
+
+ /* Weak references */
+ size_t weak_references_count;
+ } profile;
+
+ VALUE gc_stress_mode;
+
+ struct {
+ bool parent_object_old_p;
+ VALUE parent_object;
+
+ int need_major_gc;
+ size_t last_major_gc;
+ size_t uncollectible_wb_unprotected_objects;
+ size_t uncollectible_wb_unprotected_objects_limit;
+ size_t old_objects;
+ size_t old_objects_limit;
+
+#if RGENGC_ESTIMATE_OLDMALLOC
+ size_t oldmalloc_increase_limit;
+#endif
+
+#if RGENGC_CHECK_MODE >= 2
+ struct st_table *allrefs_table;
+ size_t error_count;
+#endif
+ } rgengc;
+
+ struct {
+ size_t considered_count_table[T_MASK];
+ size_t moved_count_table[T_MASK];
+ size_t moved_up_count_table[T_MASK];
+ size_t moved_down_count_table[T_MASK];
+ size_t total_moved;
+
+ /* This function will be used, if set, to sort the heap prior to compaction */
+ gc_compact_compare_func compare_func;
+ } rcompactor;
+
+ struct {
+ size_t pooled_slots;
+ size_t step_slots;
+ } rincgc;
+
+#if GC_DEBUG_STRESS_TO_CLASS
+ VALUE stress_to_class;
+#endif
+
+ rb_darray(VALUE) weak_references;
+ rb_postponed_job_handle_t finalize_deferred_pjob;
+
+ unsigned long live_ractor_cache_count;
+
+ int sweeping_heap_count;
+
+ int fork_vm_lock_lev;
+
+ struct rb_gc_vm_context vm_context;
+} rb_objspace_t;
+
+#ifndef HEAP_PAGE_ALIGN_LOG
+/* default tiny heap size: 64KiB */
+#define HEAP_PAGE_ALIGN_LOG 16
+#endif
+
+#if RB_GC_OBJ_HAS_SUFFIX || GC_DEBUG
+struct rvalue_overhead {
+# if RB_GC_OBJ_HAS_SUFFIX
+ struct rb_gc_obj_suffix suffix;
+# endif
+# if GC_DEBUG
+ const char *file;
+ int line;
+# endif
+};
+
+// Make sure that RVALUE_OVERHEAD aligns to sizeof(VALUE)
+# define RVALUE_OVERHEAD (sizeof(struct { \
+ union { \
+ struct rvalue_overhead overhead; \
+ VALUE value; \
+ }; \
+}))
+size_t rb_gc_impl_obj_slot_size(VALUE obj);
+# define GET_RVALUE_OVERHEAD(obj) ((struct rvalue_overhead *)((uintptr_t)obj + rb_gc_impl_obj_slot_size(obj)))
+#else
+# ifndef RVALUE_OVERHEAD
+# define RVALUE_OVERHEAD 0
+# endif
+#endif
+
+#define RVALUE_SLOT_SIZE (sizeof(struct RBasic) + sizeof(VALUE[RBIMPL_RVALUE_EMBED_LEN_MAX]) + RVALUE_OVERHEAD)
+
+static const size_t pool_slot_sizes[HEAP_COUNT] = {
+#define SLOT(size) ((size) + RVALUE_OVERHEAD),
+ EACH_POOL_SLOT_SIZE(SLOT)
+#undef SLOT
+};
+
+/* Precomputed reciprocals for fast slot index calculation.
+ * For slot size d: reciprocal = ceil(2^48 / d).
+ * Then offset / d == (uint32_t)((offset * reciprocal) >> 48)
+ * for all offset < HEAP_PAGE_SIZE. */
+#define SLOT_RECIPROCAL_SHIFT 48
+#define SLOT_RECIPROCAL(size) (((1ULL << SLOT_RECIPROCAL_SHIFT) + (size) - 1) / (size))
+
+static const uint64_t heap_slot_reciprocal_table[HEAP_COUNT] = {
+#define SLOT(size) SLOT_RECIPROCAL((size) + RVALUE_OVERHEAD),
+ EACH_POOL_SLOT_SIZE(SLOT)
+#undef SLOT
+};
+
+#if SIZEOF_VALUE >= 8
+static uint8_t size_to_heap_idx[1024 / 8 + 1];
+#else
+static uint8_t size_to_heap_idx[512 / 8 + 1];
+#endif
+
+#ifndef MAX
+# define MAX(a, b) (((a) > (b)) ? (a) : (b))
+#endif
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+#define roomof(x, y) (((x) + (y) - 1) / (y))
+#define CEILDIV(i, mod) roomof(i, mod)
+#define MIN_POOL_SLOT_SIZE 32
+enum {
+ HEAP_PAGE_ALIGN = (1UL << HEAP_PAGE_ALIGN_LOG),
+ HEAP_PAGE_ALIGN_MASK = (~(~0UL << HEAP_PAGE_ALIGN_LOG)),
+ HEAP_PAGE_SIZE = HEAP_PAGE_ALIGN,
+ HEAP_PAGE_BITMAP_LIMIT = CEILDIV(CEILDIV(HEAP_PAGE_SIZE, MIN_POOL_SLOT_SIZE), BITS_BITLENGTH),
+ HEAP_PAGE_BITMAP_SIZE = (BITS_SIZE * HEAP_PAGE_BITMAP_LIMIT),
+};
+#define HEAP_PAGE_ALIGN (1 << HEAP_PAGE_ALIGN_LOG)
+#define HEAP_PAGE_SIZE HEAP_PAGE_ALIGN
+
+#if !defined(INCREMENTAL_MARK_STEP_ALLOCATIONS)
+# define INCREMENTAL_MARK_STEP_ALLOCATIONS 500
+#endif
+
+#undef INIT_HEAP_PAGE_ALLOC_USE_MMAP
+/* Must define either HEAP_PAGE_ALLOC_USE_MMAP or
+ * INIT_HEAP_PAGE_ALLOC_USE_MMAP. */
+
+#ifndef HAVE_MMAP
+/* We can't use mmap of course, if it is not available. */
+static const bool HEAP_PAGE_ALLOC_USE_MMAP = false;
+
+#elif defined(__wasm__)
+/* wasmtime does not have proper support for mmap.
+ * See https://github.com/bytecodealliance/wasmtime/blob/main/docs/WASI-rationale.md#why-no-mmap-and-friends
+ */
+static const bool HEAP_PAGE_ALLOC_USE_MMAP = false;
+
+#elif HAVE_CONST_PAGE_SIZE
+/* If we have the PAGE_SIZE and it is a constant, then we can directly use it. */
+static const bool HEAP_PAGE_ALLOC_USE_MMAP = (PAGE_SIZE <= HEAP_PAGE_SIZE);
+
+#elif defined(PAGE_MAX_SIZE) && (PAGE_MAX_SIZE <= HEAP_PAGE_SIZE)
+/* If we can use the maximum page size. */
+static const bool HEAP_PAGE_ALLOC_USE_MMAP = true;
+
+#elif defined(PAGE_SIZE)
+/* If the PAGE_SIZE macro can be used dynamically. */
+# define INIT_HEAP_PAGE_ALLOC_USE_MMAP (PAGE_SIZE <= HEAP_PAGE_SIZE)
+
+#elif defined(HAVE_SYSCONF) && defined(_SC_PAGE_SIZE)
+/* If we can use sysconf to determine the page size. */
+# define INIT_HEAP_PAGE_ALLOC_USE_MMAP (sysconf(_SC_PAGE_SIZE) <= HEAP_PAGE_SIZE)
+
+#else
+/* Otherwise we can't determine the system page size, so don't use mmap. */
+static const bool HEAP_PAGE_ALLOC_USE_MMAP = false;
+#endif
+
+#ifdef INIT_HEAP_PAGE_ALLOC_USE_MMAP
+/* We can determine the system page size at runtime. */
+# define HEAP_PAGE_ALLOC_USE_MMAP (heap_page_alloc_use_mmap != false)
+
+static bool heap_page_alloc_use_mmap;
+#endif
+
+#define RVALUE_AGE_BIT_COUNT 2
+#define RVALUE_AGE_BIT_MASK (((bits_t)1 << RVALUE_AGE_BIT_COUNT) - 1)
+#define RVALUE_OLD_AGE 3
+
+struct free_slot {
+ VALUE flags; /* always 0 for freed obj */
+ struct free_slot *next;
+};
+
+struct heap_page {
+ /* Cache line 0: allocation fast path + SLOT_INDEX */
+ struct free_slot *freelist;
+ uintptr_t start;
+ uint64_t slot_size_reciprocal;
+ unsigned short slot_size;
+ unsigned short total_slots;
+ unsigned short free_slots;
+ unsigned short final_slots;
+ unsigned short pinned_slots;
+ struct {
+ unsigned int before_sweep : 1;
+ unsigned int has_remembered_objects : 1;
+ unsigned int has_uncollectible_wb_unprotected_objects : 1;
+ } flags;
+
+ rb_heap_t *heap;
+
+ struct heap_page *free_next;
+ struct heap_page_body *body;
+ struct ccan_list_node page_node;
+
+ bits_t wb_unprotected_bits[HEAP_PAGE_BITMAP_LIMIT];
+ /* the following three bitmaps are cleared at the beginning of full GC */
+ bits_t mark_bits[HEAP_PAGE_BITMAP_LIMIT];
+ bits_t uncollectible_bits[HEAP_PAGE_BITMAP_LIMIT];
+ bits_t marking_bits[HEAP_PAGE_BITMAP_LIMIT];
+
+ bits_t remembered_bits[HEAP_PAGE_BITMAP_LIMIT];
+
+ /* If set, the object is not movable */
+ bits_t pinned_bits[HEAP_PAGE_BITMAP_LIMIT];
+ bits_t age_bits[HEAP_PAGE_BITMAP_LIMIT * RVALUE_AGE_BIT_COUNT];
+};
+
+/*
+ * When asan is enabled, this will prohibit writing to the freelist until it is unlocked
+ */
+static void
+asan_lock_freelist(struct heap_page *page)
+{
+ asan_poison_memory_region(&page->freelist, sizeof(struct free_list *));
+}
+
+/*
+ * When asan is enabled, this will enable the ability to write to the freelist
+ */
+static void
+asan_unlock_freelist(struct heap_page *page)
+{
+ asan_unpoison_memory_region(&page->freelist, sizeof(struct free_list *), false);
+}
+
+static inline bool
+heap_page_in_global_empty_pages_pool(rb_objspace_t *objspace, struct heap_page *page)
+{
+ if (page->total_slots == 0) {
+ GC_ASSERT(page->start == 0);
+ GC_ASSERT(page->slot_size == 0);
+ GC_ASSERT(page->heap == NULL);
+ GC_ASSERT(page->free_slots == 0);
+ asan_unpoisoning_memory_region(&page->freelist, sizeof(&page->freelist)) {
+ GC_ASSERT(page->freelist == NULL);
+ }
+
+ return true;
+ }
+ else {
+ GC_ASSERT(page->start != 0);
+ GC_ASSERT(page->slot_size != 0);
+ GC_ASSERT(page->heap != NULL);
+
+ return false;
+ }
+}
+
+#define GET_PAGE_BODY(x) ((struct heap_page_body *)((bits_t)(x) & ~(HEAP_PAGE_ALIGN_MASK)))
+#define GET_PAGE_HEADER(x) (&GET_PAGE_BODY(x)->header)
+#define GET_HEAP_PAGE(x) (GET_PAGE_HEADER(x)->page)
+
+static inline size_t
+slot_index_for_offset(size_t offset, uint64_t reciprocal)
+{
+ return (uint32_t)(((uint64_t)offset * reciprocal) >> SLOT_RECIPROCAL_SHIFT);
+}
+
+#define SLOT_INDEX(page, p) slot_index_for_offset((uintptr_t)(p) - (page)->start, (page)->slot_size_reciprocal)
+#define SLOT_BITMAP_INDEX(page, p) (SLOT_INDEX(page, p) / BITS_BITLENGTH)
+#define SLOT_BITMAP_OFFSET(page, p) (SLOT_INDEX(page, p) & (BITS_BITLENGTH - 1))
+#define SLOT_BITMAP_BIT(page, p) ((bits_t)1 << SLOT_BITMAP_OFFSET(page, p))
+
+#define _MARKED_IN_BITMAP(bits, page, p) ((bits)[SLOT_BITMAP_INDEX(page, p)] & SLOT_BITMAP_BIT(page, p))
+#define _MARK_IN_BITMAP(bits, page, p) ((bits)[SLOT_BITMAP_INDEX(page, p)] |= SLOT_BITMAP_BIT(page, p))
+#define _CLEAR_IN_BITMAP(bits, page, p) ((bits)[SLOT_BITMAP_INDEX(page, p)] &= ~SLOT_BITMAP_BIT(page, p))
+
+#define MARKED_IN_BITMAP(bits, p) _MARKED_IN_BITMAP(bits, GET_HEAP_PAGE(p), p)
+#define MARK_IN_BITMAP(bits, p) _MARK_IN_BITMAP(bits, GET_HEAP_PAGE(p), p)
+#define CLEAR_IN_BITMAP(bits, p) _CLEAR_IN_BITMAP(bits, GET_HEAP_PAGE(p), p)
+
+#define GET_HEAP_MARK_BITS(x) (&GET_HEAP_PAGE(x)->mark_bits[0])
+#define GET_HEAP_PINNED_BITS(x) (&GET_HEAP_PAGE(x)->pinned_bits[0])
+#define GET_HEAP_UNCOLLECTIBLE_BITS(x) (&GET_HEAP_PAGE(x)->uncollectible_bits[0])
+#define GET_HEAP_WB_UNPROTECTED_BITS(x) (&GET_HEAP_PAGE(x)->wb_unprotected_bits[0])
+#define GET_HEAP_MARKING_BITS(x) (&GET_HEAP_PAGE(x)->marking_bits[0])
+
+static int
+RVALUE_AGE_GET(VALUE obj)
+{
+ struct heap_page *page = GET_HEAP_PAGE(obj);
+ bits_t *age_bits = page->age_bits;
+ size_t slot_idx = SLOT_INDEX(page, obj);
+ size_t idx = (slot_idx / BITS_BITLENGTH) * 2;
+ int shift = (int)(slot_idx & (BITS_BITLENGTH - 1));
+ int lo = (age_bits[idx] >> shift) & 1;
+ int hi = (age_bits[idx + 1] >> shift) & 1;
+ return lo | (hi << 1);
+}
+
+static void
+RVALUE_AGE_SET_BITMAP(VALUE obj, int age)
+{
+ RUBY_ASSERT(age <= RVALUE_OLD_AGE);
+ struct heap_page *page = GET_HEAP_PAGE(obj);
+ bits_t *age_bits = page->age_bits;
+ size_t slot_idx = SLOT_INDEX(page, obj);
+ size_t idx = (slot_idx / BITS_BITLENGTH) * 2;
+ int shift = (int)(slot_idx & (BITS_BITLENGTH - 1));
+ bits_t mask = (bits_t)1 << shift;
+
+ age_bits[idx] = (age_bits[idx] & ~mask) | ((bits_t)(age & 1) << shift);
+ age_bits[idx + 1] = (age_bits[idx + 1] & ~mask) | ((bits_t)((age >> 1) & 1) << shift);
+}
+
+static void
+RVALUE_AGE_SET(VALUE obj, int age)
+{
+ RVALUE_AGE_SET_BITMAP(obj, age);
+ if (age == RVALUE_OLD_AGE) {
+ RB_FL_SET_RAW(obj, RUBY_FL_PROMOTED);
+ }
+ else {
+ RB_FL_UNSET_RAW(obj, RUBY_FL_PROMOTED);
+ }
+}
+
+#define malloc_limit objspace->malloc_params.limit
+#define malloc_increase gc_malloc_counters_increase_unsigned(objspace, &objspace->malloc_counters.counters)
+#define malloc_allocated_size objspace->malloc_params.allocated_size
+
+#ifdef MALLOC_COUNTERS_NEED_LOCK
+# define MALLOC_COUNTERS_LOCK(o) rb_native_mutex_lock(&(o)->malloc_counters.lock)
+# define MALLOC_COUNTERS_UNLOCK(o) rb_native_mutex_unlock(&(o)->malloc_counters.lock)
+#else
+# define MALLOC_COUNTERS_LOCK(o) ((void)0)
+# define MALLOC_COUNTERS_UNLOCK(o) ((void)0)
+#endif
+
+static inline void
+gc_counter_add(gc_counter_t *p, size_t delta)
+{
+#ifdef MALLOC_COUNTERS_NEED_LOCK
+ *p += (gc_counter_t)delta;
+#else
+ rbimpl_atomic_u64_fetch_add_relaxed(p, (uint64_t)delta);
+#endif
+}
+
+static inline gc_counter_t
+gc_counter_load_relaxed(const gc_counter_t *p)
+{
+#ifdef MALLOC_COUNTERS_NEED_LOCK
+ return *p;
+#else
+ return rbimpl_atomic_u64_load_relaxed(p);
+#endif
+}
+
+static inline gc_counter_t
+gc_counter_load_acquire(const gc_counter_t *p)
+{
+#ifdef MALLOC_COUNTERS_NEED_LOCK
+ return *p;
+#else
+ return rbimpl_atomic_u64_load_acquire(p);
+#endif
+}
+
+static inline void
+gc_counter_store_release(gc_counter_t *p, gc_counter_t v)
+{
+#ifdef MALLOC_COUNTERS_NEED_LOCK
+ *p = v;
+#else
+ rbimpl_atomic_u64_set_release(p, v);
+#endif
+}
+
+static inline int64_t
+gc_malloc_counters_increase(rb_objspace_t *objspace, const struct gc_malloc_bytes *c)
+{
+ MALLOC_COUNTERS_LOCK(objspace);
+ gc_counter_t malloc_at = gc_counter_load_acquire(&c->malloc_at_last_gc);
+ gc_counter_t free_at = gc_counter_load_acquire(&c->free_at_last_gc);
+ gc_counter_t malloc_now = gc_counter_load_relaxed(&c->malloc);
+ gc_counter_t free_now = gc_counter_load_relaxed(&c->free);
+ MALLOC_COUNTERS_UNLOCK(objspace);
+
+ gc_counter_t malloc_delta = malloc_now - malloc_at;
+ gc_counter_t free_delta = free_now - free_at;
+
+ if (malloc_delta >= free_delta) {
+ return (int64_t)(malloc_delta - free_delta);
+ }
+ else {
+ return -(int64_t)(free_delta - malloc_delta);
+ }
+}
+
+static inline size_t
+gc_malloc_counters_increase_unsigned(rb_objspace_t *objspace, const struct gc_malloc_bytes *c)
+{
+ int64_t inc = gc_malloc_counters_increase(objspace, c);
+ if (inc <= 0) return 0;
+#if SIZEOF_SIZE_T < 8
+ if ((uint64_t)inc > SIZE_MAX) return SIZE_MAX;
+#endif
+ return (size_t)inc;
+}
+
+static inline int64_t
+gc_malloc_counters_snapshot(rb_objspace_t *objspace, struct gc_malloc_bytes *c)
+{
+ MALLOC_COUNTERS_LOCK(objspace);
+ gc_counter_t malloc_now = gc_counter_load_relaxed(&c->malloc);
+ gc_counter_t free_now = gc_counter_load_relaxed(&c->free);
+ gc_counter_t malloc_at = gc_counter_load_relaxed(&c->malloc_at_last_gc);
+ gc_counter_t free_at = gc_counter_load_relaxed(&c->free_at_last_gc);
+ gc_counter_store_release(&c->malloc_at_last_gc, malloc_now);
+ gc_counter_store_release(&c->free_at_last_gc, free_now);
+ MALLOC_COUNTERS_UNLOCK(objspace);
+
+ gc_counter_t malloc_delta = malloc_now - malloc_at;
+ gc_counter_t free_delta = free_now - free_at;
+
+ if (malloc_delta >= free_delta) {
+ return (int64_t)(malloc_delta - free_delta);
+ }
+ else {
+ return -(int64_t)(free_delta - malloc_delta);
+ }
+}
+
+#define heap_pages_lomem objspace->heap_pages.range[0]
+#define heap_pages_himem objspace->heap_pages.range[1]
+#define heap_pages_freeable_pages objspace->heap_pages.freeable_pages
+#define heap_pages_deferred_final objspace->heap_pages.deferred_final
+#define heaps objspace->heaps
+#define during_gc objspace->flags.during_gc
+#define finalizing objspace->atomic_flags.finalizing
+#define finalizer_table objspace->finalizer_table
+#define ruby_gc_stressful objspace->flags.gc_stressful
+#define ruby_gc_stress_mode objspace->gc_stress_mode
+#if GC_DEBUG_STRESS_TO_CLASS
+#define stress_to_class objspace->stress_to_class
+#define set_stress_to_class(c) (stress_to_class = (c))
+#else
+#define stress_to_class ((void)objspace, 0)
+#define set_stress_to_class(c) ((void)objspace, (c))
+#endif
+
+#if 0
+#define dont_gc_on() (fprintf(stderr, "dont_gc_on@%s:%d\n", __FILE__, __LINE__), objspace->flags.dont_gc = 1)
+#define dont_gc_off() (fprintf(stderr, "dont_gc_off@%s:%d\n", __FILE__, __LINE__), objspace->flags.dont_gc = 0)
+#define dont_gc_set(b) (fprintf(stderr, "dont_gc_set(%d)@%s:%d\n", __FILE__, __LINE__), objspace->flags.dont_gc = (int)(b))
+#define dont_gc_val() (objspace->flags.dont_gc)
+#else
+#define dont_gc_on() (objspace->flags.dont_gc = 1)
+#define dont_gc_off() (objspace->flags.dont_gc = 0)
+#define dont_gc_set(b) (objspace->flags.dont_gc = (int)(b))
+#define dont_gc_val() (objspace->flags.dont_gc)
+#endif
+
+#define gc_config_full_mark_set(b) (objspace->gc_config.full_mark = (int)(b))
+#define gc_config_full_mark_val (objspace->gc_config.full_mark)
+
+#ifndef DURING_GC_COULD_MALLOC_REGION_START
+# define DURING_GC_COULD_MALLOC_REGION_START() \
+ assert(rb_during_gc()); \
+ bool _prev_enabled = rb_gc_impl_gc_enabled_p(objspace); \
+ rb_gc_impl_gc_disable(objspace, false)
+#endif
+
+#ifndef DURING_GC_COULD_MALLOC_REGION_END
+# define DURING_GC_COULD_MALLOC_REGION_END() \
+ if (_prev_enabled) rb_gc_impl_gc_enable(objspace)
+#endif
+
+static inline enum gc_mode
+gc_mode_verify(enum gc_mode mode)
+{
+#if RGENGC_CHECK_MODE > 0
+ switch (mode) {
+ case gc_mode_none:
+ case gc_mode_marking:
+ case gc_mode_sweeping:
+ case gc_mode_compacting:
+ break;
+ default:
+ rb_bug("gc_mode_verify: unreachable (%d)", (int)mode);
+ }
+#endif
+ return mode;
+}
+
+static inline bool
+has_sweeping_pages(rb_objspace_t *objspace)
+{
+ return objspace->sweeping_heap_count != 0;
+}
+
+static inline size_t
+heap_eden_total_pages(rb_objspace_t *objspace)
+{
+ size_t count = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ count += (&heaps[i])->total_pages;
+ }
+ return count;
+}
+
+static inline size_t
+total_allocated_objects(rb_objspace_t *objspace)
+{
+ size_t count = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ count += heap->total_allocated_objects;
+ }
+ return count;
+}
+
+static inline size_t
+total_freed_objects(rb_objspace_t *objspace)
+{
+ size_t count = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ count += heap->total_freed_objects;
+ }
+ return count;
+}
+
+static inline size_t
+total_final_slots_count(rb_objspace_t *objspace)
+{
+ size_t count = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ count += heap->final_slots_count;
+ }
+ return count;
+}
+
+#define gc_mode(objspace) gc_mode_verify((enum gc_mode)(objspace)->flags.mode)
+#define gc_mode_set(objspace, m) ((objspace)->flags.mode = (unsigned int)gc_mode_verify(m))
+#define gc_needs_major_flags objspace->rgengc.need_major_gc
+
+#define is_marking(objspace) (gc_mode(objspace) == gc_mode_marking)
+#define is_sweeping(objspace) (gc_mode(objspace) == gc_mode_sweeping)
+#define is_full_marking(objspace) ((objspace)->flags.during_minor_gc == FALSE)
+#define is_incremental_marking(objspace) ((objspace)->flags.during_incremental_marking != FALSE)
+#define will_be_incremental_marking(objspace) ((objspace)->rgengc.need_major_gc != GPR_FLAG_NONE)
+/*
+ * Byte budget for incremental sweep steps. Each step sweeps at most
+ * this many bytes worth of slots before yielding. The effective slot
+ * count per step is GC_INCREMENTAL_SWEEP_BYTES / heap->slot_size,
+ * so larger slot pools (which are less heavily used) naturally get
+ * fewer slots swept per step.
+ *
+ * Baseline: 2048 slots * RVALUE_SLOT_SIZE = 2048 * 40 = 81920 bytes,
+ * preserving the historical behavior for the smallest heap.
+ */
+#define GC_INCREMENTAL_SWEEP_BYTES (2048 * RVALUE_SLOT_SIZE)
+#define GC_INCREMENTAL_SWEEP_POOL_BYTES (1024 * RVALUE_SLOT_SIZE)
+#define is_lazy_sweeping(objspace) (GC_ENABLE_LAZY_SWEEP && has_sweeping_pages(objspace))
+/* In lazy sweeping or the previous incremental marking finished and did not yield a free page. */
+#define needs_continue_sweeping(objspace, heap) \
+ ((heap)->free_pages == NULL && is_lazy_sweeping(objspace))
+
+#if SIZEOF_LONG == SIZEOF_VOIDP
+# define obj_id_to_ref(objid) ((objid) ^ FIXNUM_FLAG) /* unset FIXNUM_FLAG */
+#elif SIZEOF_LONG_LONG == SIZEOF_VOIDP
+# define obj_id_to_ref(objid) (FIXNUM_P(objid) ? \
+ ((objid) ^ FIXNUM_FLAG) : (NUM2PTR(objid) << 1))
+#else
+# error not supported
+#endif
+
+struct RZombie {
+ VALUE flags;
+ VALUE next;
+ void (*dfree)(void *);
+ void *data;
+};
+
+#define RZOMBIE(o) ((struct RZombie *)(o))
+
+static bool ruby_enable_autocompact = false;
+#if RGENGC_CHECK_MODE
+static gc_compact_compare_func ruby_autocompact_compare_func;
+#endif
+
+static void init_mark_stack(mark_stack_t *stack);
+static int garbage_collect(rb_objspace_t *, unsigned int reason);
+
+static int gc_start(rb_objspace_t *objspace, unsigned int reason);
+static void gc_rest(rb_objspace_t *objspace);
+
+enum gc_enter_event {
+ gc_enter_event_start,
+ gc_enter_event_continue,
+ gc_enter_event_rest,
+ gc_enter_event_finalizer,
+};
+
+static inline void gc_enter(rb_objspace_t *objspace, enum gc_enter_event event, unsigned int *lock_lev);
+static inline void gc_exit(rb_objspace_t *objspace, enum gc_enter_event event, unsigned int *lock_lev);
+static void gc_marking_enter(rb_objspace_t *objspace);
+static void gc_marking_exit(rb_objspace_t *objspace);
+static void gc_sweeping_enter(rb_objspace_t *objspace);
+static void gc_sweeping_exit(rb_objspace_t *objspace);
+static bool gc_marks_continue(rb_objspace_t *objspace, rb_heap_t *heap);
+
+static void gc_sweep(rb_objspace_t *objspace);
+static void gc_sweep_finish_heap(rb_objspace_t *objspace, rb_heap_t *heap);
+static void gc_sweep_continue(rb_objspace_t *objspace, rb_heap_t *heap);
+
+static inline void gc_mark(rb_objspace_t *objspace, VALUE ptr);
+static inline void gc_pin(rb_objspace_t *objspace, VALUE ptr);
+static inline void gc_mark_and_pin(rb_objspace_t *objspace, VALUE ptr);
+
+static int gc_mark_stacked_objects_incremental(rb_objspace_t *, size_t count);
+NO_SANITIZE("memory", static inline bool is_pointer_to_heap(rb_objspace_t *objspace, const void *ptr));
+
+static void gc_verify_internal_consistency(void *objspace_ptr);
+
+static double getrusage_time(void);
+static inline void gc_prof_setup_new_record(rb_objspace_t *objspace, unsigned int reason);
+static inline void gc_prof_timer_start(rb_objspace_t *);
+static inline void gc_prof_timer_stop(rb_objspace_t *);
+static inline void gc_prof_mark_timer_start(rb_objspace_t *);
+static inline void gc_prof_mark_timer_stop(rb_objspace_t *);
+static inline void gc_prof_sweep_timer_start(rb_objspace_t *);
+static inline void gc_prof_sweep_timer_stop(rb_objspace_t *);
+static inline void gc_prof_set_malloc_info(rb_objspace_t *);
+static inline void gc_prof_set_heap_info(rb_objspace_t *);
+
+#define gc_prof_record(objspace) (objspace)->profile.current_record
+#define gc_prof_enabled(objspace) ((objspace)->profile.run && (objspace)->profile.current_record)
+
+#ifdef HAVE_VA_ARGS_MACRO
+# define gc_report(level, objspace, ...) \
+ if (!RGENGC_DEBUG_ENABLED(level)) {} else gc_report_body(level, objspace, __VA_ARGS__)
+#else
+# define gc_report if (!RGENGC_DEBUG_ENABLED(0)) {} else gc_report_body
+#endif
+PRINTF_ARGS(static void gc_report_body(int level, rb_objspace_t *objspace, const char *fmt, ...), 3, 4);
+
+static void gc_finalize_deferred(void *dmy);
+
+#if USE_TICK_T
+
+/* the following code is only for internal tuning. */
+
+/* Source code to use RDTSC is quoted and modified from
+ * https://www.mcs.anl.gov/~kazutomo/rdtsc.html
+ * written by Kazutomo Yoshii <kazutomo@mcs.anl.gov>
+ */
+
+#if defined(__GNUC__) && defined(__i386__)
+typedef unsigned long long tick_t;
+#define PRItick "llu"
+static inline tick_t
+tick(void)
+{
+ unsigned long long int x;
+ __asm__ __volatile__ ("rdtsc" : "=A" (x));
+ return x;
+}
+
+#elif defined(__GNUC__) && defined(__x86_64__)
+typedef unsigned long long tick_t;
+#define PRItick "llu"
+
+static __inline__ tick_t
+tick(void)
+{
+ unsigned long hi, lo;
+ __asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
+ return ((unsigned long long)lo)|( ((unsigned long long)hi)<<32);
+}
+
+#elif defined(__powerpc64__) && (GCC_VERSION_SINCE(4,8,0) || defined(__clang__))
+typedef unsigned long long tick_t;
+#define PRItick "llu"
+
+static __inline__ tick_t
+tick(void)
+{
+ unsigned long long val = __builtin_ppc_get_timebase();
+ return val;
+}
+
+#elif defined(__POWERPC__) && defined(__APPLE__)
+/* Implementation for macOS PPC by @nobu
+ * See: https://github.com/ruby/ruby/pull/5975#discussion_r890045558
+ */
+typedef unsigned long long tick_t;
+#define PRItick "llu"
+
+static __inline__ tick_t
+tick(void)
+{
+ unsigned long int upper, lower, tmp;
+ # define mftbu(r) __asm__ volatile("mftbu %0" : "=r"(r))
+ # define mftb(r) __asm__ volatile("mftb %0" : "=r"(r))
+ do {
+ mftbu(upper);
+ mftb(lower);
+ mftbu(tmp);
+ } while (tmp != upper);
+ return ((tick_t)upper << 32) | lower;
+}
+
+#elif defined(__aarch64__) && defined(__GNUC__)
+typedef unsigned long tick_t;
+#define PRItick "lu"
+
+static __inline__ tick_t
+tick(void)
+{
+ unsigned long val;
+ __asm__ __volatile__ ("mrs %0, cntvct_el0" : "=r" (val));
+ return val;
+}
+
+
+#elif defined(_WIN32) && defined(_MSC_VER)
+#include <intrin.h>
+typedef unsigned __int64 tick_t;
+#define PRItick "llu"
+
+static inline tick_t
+tick(void)
+{
+ return __rdtsc();
+}
+
+#else /* use clock */
+typedef clock_t tick_t;
+#define PRItick "llu"
+
+static inline tick_t
+tick(void)
+{
+ return clock();
+}
+#endif /* TSC */
+#else /* USE_TICK_T */
+#define MEASURE_LINE(expr) expr
+#endif /* USE_TICK_T */
+
+static inline VALUE check_rvalue_consistency(rb_objspace_t *objspace, const VALUE obj);
+
+#define RVALUE_MARKED_BITMAP(obj) MARKED_IN_BITMAP(GET_HEAP_MARK_BITS(obj), (obj))
+#define RVALUE_WB_UNPROTECTED_BITMAP(obj) MARKED_IN_BITMAP(GET_HEAP_WB_UNPROTECTED_BITS(obj), (obj))
+#define RVALUE_MARKING_BITMAP(obj) MARKED_IN_BITMAP(GET_HEAP_MARKING_BITS(obj), (obj))
+#define RVALUE_UNCOLLECTIBLE_BITMAP(obj) MARKED_IN_BITMAP(GET_HEAP_UNCOLLECTIBLE_BITS(obj), (obj))
+#define RVALUE_PINNED_BITMAP(obj) MARKED_IN_BITMAP(GET_HEAP_PINNED_BITS(obj), (obj))
+
+static inline int
+RVALUE_MARKED(rb_objspace_t *objspace, VALUE obj)
+{
+ check_rvalue_consistency(objspace, obj);
+ return RVALUE_MARKED_BITMAP(obj) != 0;
+}
+
+static inline int
+RVALUE_PINNED(rb_objspace_t *objspace, VALUE obj)
+{
+ check_rvalue_consistency(objspace, obj);
+ return RVALUE_PINNED_BITMAP(obj) != 0;
+}
+
+static inline int
+RVALUE_WB_UNPROTECTED(rb_objspace_t *objspace, VALUE obj)
+{
+ check_rvalue_consistency(objspace, obj);
+ return RVALUE_WB_UNPROTECTED_BITMAP(obj) != 0;
+}
+
+static inline int
+RVALUE_MARKING(rb_objspace_t *objspace, VALUE obj)
+{
+ check_rvalue_consistency(objspace, obj);
+ return RVALUE_MARKING_BITMAP(obj) != 0;
+}
+
+static inline int
+RVALUE_REMEMBERED(rb_objspace_t *objspace, VALUE obj)
+{
+ check_rvalue_consistency(objspace, obj);
+ return MARKED_IN_BITMAP(GET_HEAP_PAGE(obj)->remembered_bits, obj) != 0;
+}
+
+static inline int
+RVALUE_UNCOLLECTIBLE(rb_objspace_t *objspace, VALUE obj)
+{
+ check_rvalue_consistency(objspace, obj);
+ return RVALUE_UNCOLLECTIBLE_BITMAP(obj) != 0;
+}
+
+#define RVALUE_PAGE_WB_UNPROTECTED(page, obj) MARKED_IN_BITMAP((page)->wb_unprotected_bits, (obj))
+#define RVALUE_PAGE_UNCOLLECTIBLE(page, obj) MARKED_IN_BITMAP((page)->uncollectible_bits, (obj))
+#define RVALUE_PAGE_MARKING(page, obj) MARKED_IN_BITMAP((page)->marking_bits, (obj))
+
+static int rgengc_remember(rb_objspace_t *objspace, VALUE obj);
+static void rgengc_mark_and_rememberset_clear(rb_objspace_t *objspace, rb_heap_t *heap);
+static void rgengc_rememberset_mark(rb_objspace_t *objspace, rb_heap_t *heap);
+
+static int
+check_rvalue_consistency_force(rb_objspace_t *objspace, const VALUE obj, int terminate)
+{
+ int err = 0;
+
+ int lev = RB_GC_VM_LOCK_NO_BARRIER();
+ {
+ if (SPECIAL_CONST_P(obj)) {
+ fprintf(stderr, "check_rvalue_consistency: %p is a special const.\n", (void *)obj);
+ err++;
+ }
+ else if (!is_pointer_to_heap(objspace, (void *)obj)) {
+ struct heap_page *empty_page = objspace->empty_pages;
+ while (empty_page) {
+ if ((uintptr_t)empty_page->body <= (uintptr_t)obj &&
+ (uintptr_t)obj < (uintptr_t)empty_page->body + HEAP_PAGE_SIZE) {
+ GC_ASSERT(heap_page_in_global_empty_pages_pool(objspace, empty_page));
+ fprintf(stderr, "check_rvalue_consistency: %p is in an empty page (%p).\n",
+ (void *)obj, (void *)empty_page);
+ err++;
+ goto skip;
+ }
+ }
+ fprintf(stderr, "check_rvalue_consistency: %p is not a Ruby object.\n", (void *)obj);
+ err++;
+ skip:
+ ;
+ }
+ else {
+ const int wb_unprotected_bit = RVALUE_WB_UNPROTECTED_BITMAP(obj) != 0;
+ const int uncollectible_bit = RVALUE_UNCOLLECTIBLE_BITMAP(obj) != 0;
+ const int mark_bit = RVALUE_MARKED_BITMAP(obj) != 0;
+ const int marking_bit = RVALUE_MARKING_BITMAP(obj) != 0;
+ const int remembered_bit = MARKED_IN_BITMAP(GET_HEAP_PAGE(obj)->remembered_bits, obj) != 0;
+ const int age = RVALUE_AGE_GET((VALUE)obj);
+
+ if (heap_page_in_global_empty_pages_pool(objspace, GET_HEAP_PAGE(obj))) {
+ fprintf(stderr, "check_rvalue_consistency: %s is in tomb page.\n", rb_obj_info(obj));
+ err++;
+ }
+ if (BUILTIN_TYPE(obj) == T_NONE) {
+ fprintf(stderr, "check_rvalue_consistency: %s is T_NONE.\n", rb_obj_info(obj));
+ err++;
+ }
+ if (BUILTIN_TYPE(obj) == T_ZOMBIE) {
+ fprintf(stderr, "check_rvalue_consistency: %s is T_ZOMBIE.\n", rb_obj_info(obj));
+ err++;
+ }
+
+ if (BUILTIN_TYPE(obj) != T_DATA) {
+ rb_obj_memsize_of((VALUE)obj);
+ }
+
+ /* check generation
+ *
+ * OLD == age == 3 && old-bitmap && mark-bit (except incremental marking)
+ */
+ if (age > 0 && wb_unprotected_bit) {
+ fprintf(stderr, "check_rvalue_consistency: %s is not WB protected, but age is %d > 0.\n", rb_obj_info(obj), age);
+ err++;
+ }
+
+ if (!is_marking(objspace) && uncollectible_bit && !mark_bit) {
+ fprintf(stderr, "check_rvalue_consistency: %s is uncollectible, but is not marked while !gc.\n", rb_obj_info(obj));
+ err++;
+ }
+
+ if (!is_full_marking(objspace)) {
+ if (uncollectible_bit && age != RVALUE_OLD_AGE && !wb_unprotected_bit) {
+ fprintf(stderr, "check_rvalue_consistency: %s is uncollectible, but not old (age: %d) and not WB unprotected.\n",
+ rb_obj_info(obj), age);
+ err++;
+ }
+ if (remembered_bit && age != RVALUE_OLD_AGE) {
+ fprintf(stderr, "check_rvalue_consistency: %s is remembered, but not old (age: %d).\n",
+ rb_obj_info(obj), age);
+ err++;
+ }
+ }
+
+ /*
+ * check coloring
+ *
+ * marking:false marking:true
+ * marked:false white *invalid*
+ * marked:true black grey
+ */
+ if (is_incremental_marking(objspace) && marking_bit) {
+ if (!is_marking(objspace) && !mark_bit) {
+ fprintf(stderr, "check_rvalue_consistency: %s is marking, but not marked.\n", rb_obj_info(obj));
+ err++;
+ }
+ }
+ }
+ }
+ RB_GC_VM_UNLOCK_NO_BARRIER(lev);
+
+ if (err > 0 && terminate) {
+ rb_bug("check_rvalue_consistency_force: there is %d errors.", err);
+ }
+ return err;
+}
+
+#if RGENGC_CHECK_MODE == 0
+static inline VALUE
+check_rvalue_consistency(rb_objspace_t *objspace, const VALUE obj)
+{
+ return obj;
+}
+#else
+static VALUE
+check_rvalue_consistency(rb_objspace_t *objspace, const VALUE obj)
+{
+ check_rvalue_consistency_force(objspace, obj, TRUE);
+ return obj;
+}
+#endif
+
+static inline bool
+gc_object_moved_p(rb_objspace_t *objspace, VALUE obj)
+{
+
+ bool ret;
+ asan_unpoisoning_object(obj) {
+ ret = BUILTIN_TYPE(obj) == T_MOVED;
+ }
+ return ret;
+}
+
+static inline int
+RVALUE_OLD_P(rb_objspace_t *objspace, VALUE obj)
+{
+ GC_ASSERT(!RB_SPECIAL_CONST_P(obj));
+ check_rvalue_consistency(objspace, obj);
+ // Because this will only ever be called on GC controlled objects,
+ // we can use the faster _RAW function here
+ return RB_OBJ_PROMOTED_RAW(obj);
+}
+
+static inline void
+RVALUE_PAGE_OLD_UNCOLLECTIBLE_SET(rb_objspace_t *objspace, struct heap_page *page, VALUE obj)
+{
+ MARK_IN_BITMAP(&page->uncollectible_bits[0], obj);
+ objspace->rgengc.old_objects++;
+
+#if RGENGC_PROFILE >= 2
+ objspace->profile.total_promoted_count++;
+ objspace->profile.promoted_types[BUILTIN_TYPE(obj)]++;
+#endif
+}
+
+static inline void
+RVALUE_OLD_UNCOLLECTIBLE_SET(rb_objspace_t *objspace, VALUE obj)
+{
+ RB_DEBUG_COUNTER_INC(obj_promote);
+ RVALUE_PAGE_OLD_UNCOLLECTIBLE_SET(objspace, GET_HEAP_PAGE(obj), obj);
+}
+
+/* set age to age+1 */
+static inline void
+RVALUE_AGE_INC(rb_objspace_t *objspace, VALUE obj)
+{
+ int age = RVALUE_AGE_GET((VALUE)obj);
+
+ if (RGENGC_CHECK_MODE && age == RVALUE_OLD_AGE) {
+ rb_bug("RVALUE_AGE_INC: can not increment age of OLD object %s.", rb_obj_info(obj));
+ }
+
+ age++;
+ RVALUE_AGE_SET(obj, age);
+
+ if (age == RVALUE_OLD_AGE) {
+ RVALUE_OLD_UNCOLLECTIBLE_SET(objspace, obj);
+ }
+
+ check_rvalue_consistency(objspace, obj);
+}
+
+static inline void
+RVALUE_AGE_SET_CANDIDATE(rb_objspace_t *objspace, VALUE obj)
+{
+ check_rvalue_consistency(objspace, obj);
+ GC_ASSERT(!RVALUE_OLD_P(objspace, obj));
+ RVALUE_AGE_SET(obj, RVALUE_OLD_AGE - 1);
+ check_rvalue_consistency(objspace, obj);
+}
+
+static inline void
+RVALUE_AGE_RESET(VALUE obj)
+{
+ RVALUE_AGE_SET(obj, 0);
+}
+
+static inline void
+RVALUE_DEMOTE(rb_objspace_t *objspace, VALUE obj)
+{
+ check_rvalue_consistency(objspace, obj);
+ GC_ASSERT(RVALUE_OLD_P(objspace, obj));
+
+ if (!is_incremental_marking(objspace) && RVALUE_REMEMBERED(objspace, obj)) {
+ CLEAR_IN_BITMAP(GET_HEAP_PAGE(obj)->remembered_bits, obj);
+ }
+
+ CLEAR_IN_BITMAP(GET_HEAP_UNCOLLECTIBLE_BITS(obj), obj);
+ RVALUE_AGE_RESET(obj);
+
+ if (RVALUE_MARKED(objspace, obj)) {
+ objspace->rgengc.old_objects--;
+ }
+
+ check_rvalue_consistency(objspace, obj);
+}
+
+static inline int
+RVALUE_BLACK_P(rb_objspace_t *objspace, VALUE obj)
+{
+ return RVALUE_MARKED(objspace, obj) && !RVALUE_MARKING(objspace, obj);
+}
+
+static inline int
+RVALUE_WHITE_P(rb_objspace_t *objspace, VALUE obj)
+{
+ return !RVALUE_MARKED(objspace, obj);
+}
+
+bool
+rb_gc_impl_gc_enabled_p(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ return !dont_gc_val();
+}
+
+void
+rb_gc_impl_gc_enable(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ dont_gc_off();
+}
+
+void
+rb_gc_impl_gc_disable(void *objspace_ptr, bool finish_current_gc)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (finish_current_gc) {
+ gc_rest(objspace);
+ }
+
+ dont_gc_on();
+}
+
+/*
+ --------------------------- ObjectSpace -----------------------------
+*/
+
+static inline void *
+calloc1(size_t n)
+{
+ return calloc(1, n);
+}
+
+void
+rb_gc_impl_set_event_hook(void *objspace_ptr, const rb_event_flag_t event)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ objspace->hook_events = event & RUBY_INTERNAL_EVENT_OBJSPACE_MASK;
+}
+
+unsigned long long
+rb_gc_impl_get_total_time(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ unsigned long long marking_time = objspace->profile.marking_time_ns;
+ unsigned long long sweeping_time = objspace->profile.sweeping_time_ns;
+
+ return marking_time + sweeping_time;
+}
+
+void
+rb_gc_impl_set_measure_total_time(void *objspace_ptr, VALUE flag)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ objspace->flags.measure_gc = RTEST(flag) ? TRUE : FALSE;
+}
+
+bool
+rb_gc_impl_get_measure_total_time(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ return objspace->flags.measure_gc;
+}
+
+/* garbage objects will be collected soon. */
+bool
+rb_gc_impl_garbage_object_p(void *objspace_ptr, VALUE ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ bool dead = false;
+
+ asan_unpoisoning_object(ptr) {
+ switch (BUILTIN_TYPE(ptr)) {
+ case T_NONE:
+ case T_MOVED:
+ case T_ZOMBIE:
+ dead = true;
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (dead) return true;
+ return is_lazy_sweeping(objspace) && GET_HEAP_PAGE(ptr)->flags.before_sweep &&
+ !RVALUE_MARKED(objspace, ptr);
+}
+
+struct rb_gc_vm_context *
+rb_gc_impl_get_vm_context(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ return &objspace->vm_context;
+}
+
+static void free_stack_chunks(mark_stack_t *);
+static void mark_stack_free_cache(mark_stack_t *);
+static void heap_page_free(rb_objspace_t *objspace, struct heap_page *page);
+
+static inline void
+heap_page_add_freeobj(rb_objspace_t *objspace, struct heap_page *page, VALUE obj)
+{
+ rb_asan_unpoison_object(obj, false);
+
+ asan_unlock_freelist(page);
+
+ struct free_slot *slot = (struct free_slot *)obj;
+ slot->flags = 0;
+ slot->next = page->freelist;
+ page->freelist = slot;
+ asan_lock_freelist(page);
+
+ // Should have already been reset
+ GC_ASSERT(RVALUE_AGE_GET(obj) == 0);
+
+ if (RGENGC_CHECK_MODE &&
+ /* obj should belong to page */
+ !(page->start <= (uintptr_t)obj &&
+ (uintptr_t)obj < ((uintptr_t)page->start + (page->total_slots * page->slot_size)) &&
+ obj % sizeof(VALUE) == 0)) {
+ rb_bug("heap_page_add_freeobj: %p is not rvalue.", (void *)obj);
+ }
+
+ rb_asan_poison_object(obj);
+ gc_report(3, objspace, "heap_page_add_freeobj: add %p to freelist\n", (void *)obj);
+}
+
+static void
+heap_allocatable_bytes_expand(rb_objspace_t *objspace,
+ rb_heap_t *heap, size_t free_slots, size_t total_slots, size_t slot_size)
+{
+ double goal_ratio = gc_params.heap_free_slots_goal_ratio;
+ size_t target_total_slots;
+
+ if (goal_ratio == 0.0) {
+ target_total_slots = (size_t)(total_slots * gc_params.growth_factor);
+ }
+ else if (total_slots == 0) {
+ target_total_slots = gc_params.heap_init_bytes / slot_size;
+ }
+ else {
+ /* Find `f' where free_slots = f * total_slots * goal_ratio
+ * => f = (total_slots - free_slots) / ((1 - goal_ratio) * total_slots)
+ */
+ double f = (double)(total_slots - free_slots) / ((1 - goal_ratio) * total_slots);
+
+ if (f > gc_params.growth_factor) f = gc_params.growth_factor;
+ if (f < 1.0) f = 1.1;
+
+ target_total_slots = (size_t)(f * total_slots);
+
+ if (0) {
+ fprintf(stderr,
+ "free_slots(%8"PRIuSIZE")/total_slots(%8"PRIuSIZE")=%1.2f,"
+ " G(%1.2f), f(%1.2f),"
+ " total_slots(%8"PRIuSIZE") => target_total_slots(%8"PRIuSIZE")\n",
+ free_slots, total_slots, free_slots/(double)total_slots,
+ goal_ratio, f, total_slots, target_total_slots);
+ }
+ }
+
+ if (gc_params.growth_max_bytes > 0) {
+ size_t max_total_slots = total_slots + gc_params.growth_max_bytes / slot_size;
+ if (target_total_slots > max_total_slots) target_total_slots = max_total_slots;
+ }
+
+ size_t extend_slot_count = target_total_slots - total_slots;
+ /* Extend by at least 1 page. */
+ if (extend_slot_count == 0) extend_slot_count = 1;
+
+ objspace->heap_pages.allocatable_bytes += extend_slot_count * slot_size;
+}
+
+static inline void
+heap_add_freepage(rb_heap_t *heap, struct heap_page *page)
+{
+ asan_unlock_freelist(page);
+ GC_ASSERT(page->free_slots != 0);
+ GC_ASSERT(page->freelist != NULL);
+
+ page->free_next = heap->free_pages;
+ heap->free_pages = page;
+
+ RUBY_DEBUG_LOG("page:%p freelist:%p", (void *)page, (void *)page->freelist);
+
+ asan_lock_freelist(page);
+}
+
+static inline void
+heap_add_poolpage(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *page)
+{
+ asan_unlock_freelist(page);
+ GC_ASSERT(page->free_slots != 0);
+ GC_ASSERT(page->freelist != NULL);
+
+ page->free_next = heap->pooled_pages;
+ heap->pooled_pages = page;
+ objspace->rincgc.pooled_slots += page->free_slots;
+
+ asan_lock_freelist(page);
+}
+
+static void
+heap_unlink_page(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *page)
+{
+ ccan_list_del(&page->page_node);
+ heap->total_pages--;
+ heap->total_slots -= page->total_slots;
+}
+
+static void
+gc_aligned_free(void *ptr, size_t size)
+{
+#if defined __MINGW32__
+ __mingw_aligned_free(ptr);
+#elif defined _WIN32
+ _aligned_free(ptr);
+#elif defined(HAVE_POSIX_MEMALIGN) || defined(HAVE_MEMALIGN)
+ free(ptr);
+#else
+ free(((void**)ptr)[-1]);
+#endif
+}
+
+static void
+heap_page_body_free(struct heap_page_body *page_body)
+{
+ GC_ASSERT((uintptr_t)page_body % HEAP_PAGE_ALIGN == 0);
+
+ if (HEAP_PAGE_ALLOC_USE_MMAP) {
+#ifdef HAVE_MMAP
+ GC_ASSERT(HEAP_PAGE_SIZE % sysconf(_SC_PAGE_SIZE) == 0);
+ if (munmap(page_body, HEAP_PAGE_SIZE)) {
+ rb_bug("heap_page_body_free: munmap failed");
+ }
+#endif
+ }
+ else {
+ gc_aligned_free(page_body, HEAP_PAGE_SIZE);
+ }
+}
+
+static void
+heap_page_free(rb_objspace_t *objspace, struct heap_page *page)
+{
+ objspace->heap_pages.freed_pages++;
+ heap_page_body_free(page->body);
+ free(page);
+}
+
+static void
+heap_pages_free_unused_pages(rb_objspace_t *objspace)
+{
+ if (objspace->empty_pages != NULL && heap_pages_freeable_pages > 0) {
+ GC_ASSERT(objspace->empty_pages_count > 0);
+ objspace->empty_pages = NULL;
+ objspace->empty_pages_count = 0;
+
+ size_t i, j;
+ for (i = j = 0; i < rb_darray_size(objspace->heap_pages.sorted); i++) {
+ struct heap_page *page = rb_darray_get(objspace->heap_pages.sorted, i);
+
+ if (heap_page_in_global_empty_pages_pool(objspace, page) && heap_pages_freeable_pages > 0) {
+ heap_page_free(objspace, page);
+ heap_pages_freeable_pages--;
+ }
+ else {
+ if (heap_page_in_global_empty_pages_pool(objspace, page)) {
+ page->free_next = objspace->empty_pages;
+ objspace->empty_pages = page;
+ objspace->empty_pages_count++;
+ }
+
+ if (i != j) {
+ rb_darray_set(objspace->heap_pages.sorted, j, page);
+ }
+ j++;
+ }
+ }
+
+ rb_darray_pop(objspace->heap_pages.sorted, i - j);
+ GC_ASSERT(rb_darray_size(objspace->heap_pages.sorted) == j);
+
+ struct heap_page *hipage = rb_darray_get(objspace->heap_pages.sorted, rb_darray_size(objspace->heap_pages.sorted) - 1);
+ uintptr_t himem = (uintptr_t)hipage->body + HEAP_PAGE_SIZE;
+ GC_ASSERT(himem <= heap_pages_himem);
+ heap_pages_himem = himem;
+
+ struct heap_page *lopage = rb_darray_get(objspace->heap_pages.sorted, 0);
+ uintptr_t lomem = (uintptr_t)lopage->body + sizeof(struct heap_page_header);
+ GC_ASSERT(lomem >= heap_pages_lomem);
+ heap_pages_lomem = lomem;
+ }
+}
+
+static void *
+gc_aligned_malloc(size_t alignment, size_t size)
+{
+ /* alignment must be a power of 2 */
+ GC_ASSERT(((alignment - 1) & alignment) == 0);
+ GC_ASSERT(alignment % sizeof(void*) == 0);
+
+ void *res;
+
+#if defined __MINGW32__
+ res = __mingw_aligned_malloc(size, alignment);
+#elif defined _WIN32
+ void *_aligned_malloc(size_t, size_t);
+ res = _aligned_malloc(size, alignment);
+#elif defined(HAVE_POSIX_MEMALIGN)
+ if (posix_memalign(&res, alignment, size) != 0) {
+ return NULL;
+ }
+#elif defined(HAVE_MEMALIGN)
+ res = memalign(alignment, size);
+#else
+ char* aligned;
+ res = malloc(alignment + size + sizeof(void*));
+ aligned = (char*)res + alignment + sizeof(void*);
+ aligned -= ((VALUE)aligned & (alignment - 1));
+ ((void**)aligned)[-1] = res;
+ res = (void*)aligned;
+#endif
+
+ GC_ASSERT((uintptr_t)res % alignment == 0);
+
+ return res;
+}
+
+static struct heap_page_body *
+heap_page_body_allocate(void)
+{
+ struct heap_page_body *page_body;
+
+ if (HEAP_PAGE_ALLOC_USE_MMAP) {
+#ifdef HAVE_MMAP
+ GC_ASSERT(HEAP_PAGE_ALIGN % sysconf(_SC_PAGE_SIZE) == 0);
+
+ size_t mmap_size = HEAP_PAGE_ALIGN + HEAP_PAGE_SIZE;
+ char *ptr = mmap(NULL, mmap_size,
+ PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ if (ptr == MAP_FAILED) {
+ return NULL;
+ }
+
+ // If we are building `default.c` as part of the ruby executable, we
+ // may just call `ruby_annotate_mmap`. But if we are building
+ // `default.c` as a shared library, we will not have access to private
+ // symbols, and we have to either call prctl directly or make our own
+ // wrapper.
+#if defined(HAVE_SYS_PRCTL_H) && defined(PR_SET_VMA) && defined(PR_SET_VMA_ANON_NAME)
+ prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, mmap_size, "Ruby:GC:default:heap_page_body_allocate");
+ errno = 0;
+#endif
+
+ char *aligned = ptr + HEAP_PAGE_ALIGN;
+ aligned -= ((VALUE)aligned & (HEAP_PAGE_ALIGN - 1));
+ GC_ASSERT(aligned > ptr);
+ GC_ASSERT(aligned <= ptr + HEAP_PAGE_ALIGN);
+
+ size_t start_out_of_range_size = aligned - ptr;
+ GC_ASSERT(start_out_of_range_size % sysconf(_SC_PAGE_SIZE) == 0);
+ if (start_out_of_range_size > 0) {
+ if (munmap(ptr, start_out_of_range_size)) {
+ rb_bug("heap_page_body_allocate: munmap failed for start");
+ }
+ }
+
+ size_t end_out_of_range_size = HEAP_PAGE_ALIGN - start_out_of_range_size;
+ GC_ASSERT(end_out_of_range_size % sysconf(_SC_PAGE_SIZE) == 0);
+ if (end_out_of_range_size > 0) {
+ if (munmap(aligned + HEAP_PAGE_SIZE, end_out_of_range_size)) {
+ rb_bug("heap_page_body_allocate: munmap failed for end");
+ }
+ }
+
+ page_body = (struct heap_page_body *)aligned;
+#endif
+ }
+ else {
+ page_body = gc_aligned_malloc(HEAP_PAGE_ALIGN, HEAP_PAGE_SIZE);
+ }
+
+ GC_ASSERT((uintptr_t)page_body % HEAP_PAGE_ALIGN == 0);
+
+ return page_body;
+}
+
+static struct heap_page *
+heap_page_resurrect(rb_objspace_t *objspace)
+{
+ struct heap_page *page = NULL;
+ if (objspace->empty_pages == NULL) {
+ GC_ASSERT(objspace->empty_pages_count == 0);
+ }
+ else {
+ GC_ASSERT(objspace->empty_pages_count > 0);
+ objspace->empty_pages_count--;
+ page = objspace->empty_pages;
+ objspace->empty_pages = page->free_next;
+ }
+
+ return page;
+}
+
+static struct heap_page *
+heap_page_allocate(rb_objspace_t *objspace)
+{
+ struct heap_page_body *page_body = heap_page_body_allocate();
+ if (page_body == 0) {
+ rb_memerror();
+ }
+
+ struct heap_page *page = calloc1(sizeof(struct heap_page));
+ if (page == 0) {
+ heap_page_body_free(page_body);
+ rb_memerror();
+ }
+
+ uintptr_t start = (uintptr_t)page_body + sizeof(struct heap_page_header);
+ uintptr_t end = (uintptr_t)page_body + HEAP_PAGE_SIZE;
+
+ size_t lo = 0;
+ size_t hi = rb_darray_size(objspace->heap_pages.sorted);
+ while (lo < hi) {
+ struct heap_page *mid_page;
+
+ size_t mid = (lo + hi) / 2;
+ mid_page = rb_darray_get(objspace->heap_pages.sorted, mid);
+ if ((uintptr_t)mid_page->start < start) {
+ lo = mid + 1;
+ }
+ else if ((uintptr_t)mid_page->start > start) {
+ hi = mid;
+ }
+ else {
+ rb_bug("same heap page is allocated: %p at %"PRIuVALUE, (void *)page_body, (VALUE)mid);
+ }
+ }
+
+ rb_darray_insert_without_gc(&objspace->heap_pages.sorted, hi, page);
+
+ if (heap_pages_lomem == 0 || heap_pages_lomem > start) heap_pages_lomem = start;
+ if (heap_pages_himem < end) heap_pages_himem = end;
+
+ page->body = page_body;
+ page_body->header.page = page;
+
+ objspace->heap_pages.allocated_pages++;
+
+ return page;
+}
+
+static void
+heap_add_page(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *page)
+{
+ /* Adding to eden heap during incremental sweeping is forbidden */
+ GC_ASSERT(!heap->sweeping_page);
+ GC_ASSERT(heap_page_in_global_empty_pages_pool(objspace, page));
+
+ /* Align start to slot_size boundary */
+ uintptr_t start = (uintptr_t)page->body + sizeof(struct heap_page_header);
+ uintptr_t rem = start % heap->slot_size;
+ if (rem) start += heap->slot_size - rem;
+
+ int slot_count = (int)((HEAP_PAGE_SIZE - (start - (uintptr_t)page->body))/heap->slot_size);
+
+ page->start = start;
+ page->total_slots = slot_count;
+ page->slot_size = heap->slot_size;
+ page->slot_size_reciprocal = heap_slot_reciprocal_table[heap - heaps];
+ page->heap = heap;
+
+ memset(&page->wb_unprotected_bits[0], 0, HEAP_PAGE_BITMAP_SIZE);
+ memset(&page->age_bits[0], 0, sizeof(page->age_bits));
+
+ asan_unlock_freelist(page);
+ page->freelist = NULL;
+ asan_unpoison_memory_region(page->body, HEAP_PAGE_SIZE, false);
+ for (VALUE p = (VALUE)start; p < start + (slot_count * heap->slot_size); p += heap->slot_size) {
+ heap_page_add_freeobj(objspace, page, p);
+ }
+ asan_lock_freelist(page);
+
+ page->free_slots = slot_count;
+
+ heap->total_allocated_pages++;
+
+ ccan_list_add_tail(&heap->pages, &page->page_node);
+ heap->total_pages++;
+ heap->total_slots += page->total_slots;
+}
+
+static int
+heap_page_allocate_and_initialize(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ gc_report(1, objspace, "heap_page_allocate_and_initialize: rb_darray_size(objspace->heap_pages.sorted): %"PRIdSIZE", "
+ "allocatable_bytes: %"PRIdSIZE", heap->total_pages: %"PRIdSIZE"\n",
+ rb_darray_size(objspace->heap_pages.sorted), objspace->heap_pages.allocatable_bytes, heap->total_pages);
+
+ bool allocated = false;
+ struct heap_page *page = heap_page_resurrect(objspace);
+
+ if (page == NULL && objspace->heap_pages.allocatable_bytes > 0) {
+ page = heap_page_allocate(objspace);
+ allocated = true;
+
+ GC_ASSERT(page != NULL);
+ }
+
+ if (page != NULL) {
+ heap_add_page(objspace, heap, page);
+ heap_add_freepage(heap, page);
+
+ if (allocated) {
+ size_t page_bytes = (size_t)page->total_slots * page->slot_size;
+ if (objspace->heap_pages.allocatable_bytes > page_bytes) {
+ objspace->heap_pages.allocatable_bytes -= page_bytes;
+ }
+ else {
+ objspace->heap_pages.allocatable_bytes = 0;
+ }
+ }
+ }
+
+ return page != NULL;
+}
+
+static void
+heap_page_allocate_and_initialize_force(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ size_t prev_allocatable_bytes = objspace->heap_pages.allocatable_bytes;
+ objspace->heap_pages.allocatable_bytes = HEAP_PAGE_SIZE;
+ heap_page_allocate_and_initialize(objspace, heap);
+ GC_ASSERT(heap->free_pages != NULL);
+ objspace->heap_pages.allocatable_bytes = prev_allocatable_bytes;
+}
+
+static void
+gc_continue(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ unsigned int lock_lev;
+ bool needs_gc = is_incremental_marking(objspace) || needs_continue_sweeping(objspace, heap);
+ if (!needs_gc) return;
+
+ gc_enter(objspace, gc_enter_event_continue, &lock_lev); // takes vm barrier, try to avoid
+
+ /* Continue marking if in incremental marking. */
+ if (is_incremental_marking(objspace)) {
+ if (gc_marks_continue(objspace, heap)) {
+ gc_sweep(objspace);
+ }
+ }
+
+ if (needs_continue_sweeping(objspace, heap)) {
+ gc_sweep_continue(objspace, heap);
+ }
+
+ gc_exit(objspace, gc_enter_event_continue, &lock_lev);
+}
+
+static void
+heap_prepare(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ GC_ASSERT(heap->free_pages == NULL);
+
+ if (heap->total_slots < gc_params.heap_init_bytes / heap->slot_size &&
+ heap->sweeping_page == NULL) {
+ heap_page_allocate_and_initialize_force(objspace, heap);
+ GC_ASSERT(heap->free_pages != NULL);
+ return;
+ }
+
+ /* Continue incremental marking or lazy sweeping, if in any of those steps. */
+ gc_continue(objspace, heap);
+
+ if (heap->free_pages == NULL) {
+ heap_page_allocate_and_initialize(objspace, heap);
+ }
+
+ /* If we still don't have a free page and not allowed to create a new page,
+ * we should start a new GC cycle. */
+ if (heap->free_pages == NULL) {
+ GC_ASSERT(objspace->empty_pages_count == 0);
+ GC_ASSERT(objspace->heap_pages.allocatable_bytes == 0);
+
+ if (gc_start(objspace, GPR_FLAG_NEWOBJ) == FALSE) {
+ rb_memerror();
+ }
+ else {
+ if (objspace->heap_pages.allocatable_bytes == 0 && !gc_config_full_mark_val) {
+ heap_allocatable_bytes_expand(objspace, heap,
+ heap->freed_slots + heap->empty_slots,
+ heap->total_slots, heap->slot_size);
+ GC_ASSERT(objspace->heap_pages.allocatable_bytes > 0);
+ }
+ /* Do steps of incremental marking or lazy sweeping if the GC run permits. */
+ gc_continue(objspace, heap);
+
+ /* If we're not incremental marking (e.g. a minor GC) or finished
+ * sweeping and still don't have a free page, then
+ * gc_sweep_finish_heap should allow us to create a new page. */
+ if (heap->free_pages == NULL && !heap_page_allocate_and_initialize(objspace, heap)) {
+ if (gc_needs_major_flags == GPR_FLAG_NONE) {
+ rb_bug("cannot create a new page after GC");
+ }
+ else { // Major GC is required, which will allow us to create new page
+ if (gc_start(objspace, GPR_FLAG_NEWOBJ) == FALSE) {
+ rb_memerror();
+ }
+ else {
+ /* Do steps of incremental marking or lazy sweeping. */
+ gc_continue(objspace, heap);
+
+ if (heap->free_pages == NULL &&
+ !heap_page_allocate_and_initialize(objspace, heap)) {
+ rb_bug("cannot create a new page after major GC");
+ }
+ }
+ }
+ }
+ }
+ }
+
+ GC_ASSERT(heap->free_pages != NULL);
+}
+
+#if GC_DEBUG
+static inline const char*
+rb_gc_impl_source_location_cstr(int *ptr)
+{
+ /* We could directly refer `rb_source_location_cstr()` before, but not any
+ * longer. We have to heavy lift using our debugging API. */
+ if (! ptr) {
+ return NULL;
+ }
+ else if (! (*ptr = rb_sourceline())) {
+ return NULL;
+ }
+ else {
+ return rb_sourcefile();
+ }
+}
+#endif
+
+static inline VALUE
+newobj_init(VALUE klass, VALUE flags, int wb_protected, rb_objspace_t *objspace, VALUE obj)
+{
+ GC_ASSERT(BUILTIN_TYPE(obj) == T_NONE);
+ GC_ASSERT((flags & FL_WB_PROTECTED) == 0);
+ RBASIC(obj)->flags = flags;
+ *((VALUE *)&RBASIC(obj)->klass) = klass;
+#if RBASIC_SHAPE_ID_FIELD
+ RBASIC(obj)->shape_id = 0;
+#endif
+
+#if RGENGC_CHECK_MODE
+ int lev = RB_GC_VM_LOCK_NO_BARRIER();
+ {
+ check_rvalue_consistency(objspace, obj);
+
+ GC_ASSERT(RVALUE_MARKED(objspace, obj) == FALSE);
+ GC_ASSERT(RVALUE_MARKING(objspace, obj) == FALSE);
+ GC_ASSERT(RVALUE_OLD_P(objspace, obj) == FALSE);
+ GC_ASSERT(RVALUE_WB_UNPROTECTED(objspace, obj) == FALSE);
+
+ if (RVALUE_REMEMBERED(objspace, obj)) rb_bug("newobj: %s is remembered.", rb_obj_info(obj));
+ }
+ RB_GC_VM_UNLOCK_NO_BARRIER(lev);
+#endif
+
+ if (RB_UNLIKELY(wb_protected == FALSE)) {
+ MARK_IN_BITMAP(GET_HEAP_WB_UNPROTECTED_BITS(obj), obj);
+ }
+
+#if RGENGC_PROFILE
+ if (wb_protected) {
+ objspace->profile.total_generated_normal_object_count++;
+#if RGENGC_PROFILE >= 2
+ objspace->profile.generated_normal_object_count_types[BUILTIN_TYPE(obj)]++;
+#endif
+ }
+ else {
+ objspace->profile.total_generated_shady_object_count++;
+#if RGENGC_PROFILE >= 2
+ objspace->profile.generated_shady_object_count_types[BUILTIN_TYPE(obj)]++;
+#endif
+ }
+#endif
+
+#if GC_DEBUG
+ GET_RVALUE_OVERHEAD(obj)->file = rb_gc_impl_source_location_cstr(&GET_RVALUE_OVERHEAD(obj)->line);
+ GC_ASSERT(!SPECIAL_CONST_P(obj)); /* check alignment */
+#endif
+
+ gc_report(5, objspace, "newobj: %s\n", rb_obj_info(obj));
+
+ // RUBY_DEBUG_LOG("obj:%p (%s)", (void *)obj, rb_obj_info(obj));
+ return obj;
+}
+
+size_t
+rb_gc_impl_obj_slot_size(VALUE obj)
+{
+ return GET_HEAP_PAGE(obj)->slot_size - RVALUE_OVERHEAD;
+}
+
+static inline size_t
+heap_slot_size(unsigned char pool_id)
+{
+ GC_ASSERT(pool_id < HEAP_COUNT);
+
+ return pool_slot_sizes[pool_id] - RVALUE_OVERHEAD;
+}
+
+bool
+rb_gc_impl_size_allocatable_p(size_t size)
+{
+ return size + RVALUE_OVERHEAD <= pool_slot_sizes[HEAP_COUNT - 1];
+}
+
+static const size_t ALLOCATED_COUNT_STEP = 1024;
+static void
+ractor_cache_flush_count(rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache)
+{
+ for (int heap_idx = 0; heap_idx < HEAP_COUNT; heap_idx++) {
+ rb_ractor_newobj_heap_cache_t *heap_cache = &cache->heap_caches[heap_idx];
+
+ rb_heap_t *heap = &heaps[heap_idx];
+ RUBY_ATOMIC_SIZE_ADD(heap->total_allocated_objects, heap_cache->allocated_objects_count);
+ heap_cache->allocated_objects_count = 0;
+ }
+}
+
+static inline VALUE
+ractor_cache_allocate_slot(rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache,
+ size_t heap_idx)
+{
+ rb_ractor_newobj_heap_cache_t *heap_cache = &cache->heap_caches[heap_idx];
+ struct free_slot *p = heap_cache->freelist;
+
+ if (RB_UNLIKELY(is_incremental_marking(objspace))) {
+ // Not allowed to allocate without running an incremental marking step
+ if (cache->incremental_mark_step_allocated_slots >= INCREMENTAL_MARK_STEP_ALLOCATIONS) {
+ return Qfalse;
+ }
+
+ if (p) {
+ cache->incremental_mark_step_allocated_slots++;
+ }
+ }
+
+ if (RB_LIKELY(p)) {
+ VALUE obj = (VALUE)p;
+ rb_asan_unpoison_object(obj, true);
+ heap_cache->freelist = p->next;
+
+ heap_cache->allocated_objects_count++;
+ rb_heap_t *heap = &heaps[heap_idx];
+ if (heap_cache->allocated_objects_count >= ALLOCATED_COUNT_STEP) {
+ RUBY_ATOMIC_SIZE_ADD(heap->total_allocated_objects, heap_cache->allocated_objects_count);
+ heap_cache->allocated_objects_count = 0;
+ }
+
+#if RGENGC_CHECK_MODE
+ GC_ASSERT(rb_gc_impl_obj_slot_size(obj) == heap_slot_size(heap_idx));
+ // zero clear
+ MEMZERO((char *)obj, char, heap_slot_size(heap_idx));
+#endif
+ return obj;
+ }
+ else {
+ return Qfalse;
+ }
+}
+
+static struct heap_page *
+heap_next_free_page(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ struct heap_page *page;
+
+ if (heap->free_pages == NULL) {
+ heap_prepare(objspace, heap);
+ }
+
+ page = heap->free_pages;
+ heap->free_pages = page->free_next;
+
+ GC_ASSERT(page->free_slots != 0);
+
+ asan_unlock_freelist(page);
+
+ return page;
+}
+
+static inline void
+ractor_cache_set_page(rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, size_t heap_idx,
+ struct heap_page *page)
+{
+ gc_report(3, objspace, "ractor_set_cache: Using page %p\n", (void *)page->body);
+
+ rb_ractor_newobj_heap_cache_t *heap_cache = &cache->heap_caches[heap_idx];
+
+ GC_ASSERT(heap_cache->freelist == NULL);
+ GC_ASSERT(page->free_slots != 0);
+ GC_ASSERT(page->freelist != NULL);
+
+ heap_cache->using_page = page;
+ heap_cache->freelist = page->freelist;
+ page->free_slots = 0;
+ page->freelist = NULL;
+
+ rb_asan_unpoison_object((VALUE)heap_cache->freelist, false);
+ GC_ASSERT(RB_TYPE_P((VALUE)heap_cache->freelist, T_NONE));
+ rb_asan_poison_object((VALUE)heap_cache->freelist);
+}
+
+static void
+init_size_to_heap_idx(void)
+{
+ for (size_t i = 0; i < sizeof(size_to_heap_idx); i++) {
+ size_t effective = i * 8 + RVALUE_OVERHEAD;
+ uint8_t idx;
+ for (idx = 0; idx < HEAP_COUNT; idx++) {
+ if (effective <= pool_slot_sizes[idx]) break;
+ }
+ size_to_heap_idx[i] = idx;
+ }
+}
+
+static inline size_t
+heap_idx_for_size(size_t size)
+{
+ size_t compressed = (size + 7) >> 3;
+ if (compressed < sizeof(size_to_heap_idx)) {
+ size_t heap_idx = size_to_heap_idx[compressed];
+ if (RB_LIKELY(heap_idx < HEAP_COUNT)) return heap_idx;
+ }
+
+ rb_bug("heap_idx_for_size: allocation size too large "
+ "(size=%"PRIuSIZE")", size);
+}
+
+size_t
+rb_gc_impl_heap_id_for_size(void *objspace_ptr, size_t size)
+{
+ return heap_idx_for_size(size);
+}
+
+
+static size_t heap_sizes[HEAP_COUNT + 1] = { 0 };
+
+size_t *
+rb_gc_impl_heap_sizes(void *objspace_ptr)
+{
+ if (heap_sizes[0] == 0) {
+ for (unsigned char i = 0; i < HEAP_COUNT; i++) {
+ heap_sizes[i] = heap_slot_size(i);
+ }
+ }
+
+ return heap_sizes;
+}
+
+NOINLINE(static VALUE newobj_cache_miss(rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, size_t heap_idx, bool vm_locked));
+
+static VALUE
+newobj_cache_miss(rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, size_t heap_idx, bool vm_locked)
+{
+ rb_heap_t *heap = &heaps[heap_idx];
+ VALUE obj = Qfalse;
+
+ unsigned int lev = 0;
+ bool unlock_vm = false;
+
+ if (!vm_locked) {
+ lev = RB_GC_CR_LOCK();
+ unlock_vm = true;
+ }
+
+ {
+ if (is_incremental_marking(objspace)) {
+ gc_continue(objspace, heap);
+ cache->incremental_mark_step_allocated_slots = 0;
+
+ // Retry allocation after resetting incremental_mark_step_allocated_slots
+ obj = ractor_cache_allocate_slot(objspace, cache, heap_idx);
+ }
+
+ if (obj == Qfalse) {
+ // Get next free page (possibly running GC)
+ struct heap_page *page = heap_next_free_page(objspace, heap);
+ ractor_cache_set_page(objspace, cache, heap_idx, page);
+
+ // Retry allocation after moving to new page
+ obj = ractor_cache_allocate_slot(objspace, cache, heap_idx);
+ }
+ }
+
+ if (unlock_vm) {
+ RB_GC_CR_UNLOCK(lev);
+ }
+
+ if (RB_UNLIKELY(obj == Qfalse)) {
+ rb_memerror();
+ }
+ return obj;
+}
+
+static VALUE
+newobj_alloc(rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, size_t heap_idx, bool vm_locked)
+{
+ VALUE obj = ractor_cache_allocate_slot(objspace, cache, heap_idx);
+
+ if (RB_UNLIKELY(obj == Qfalse)) {
+ obj = newobj_cache_miss(objspace, cache, heap_idx, vm_locked);
+ }
+
+ return obj;
+}
+
+ALWAYS_INLINE(static VALUE newobj_slowpath(VALUE klass, VALUE flags, rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, int wb_protected, size_t heap_idx));
+
+static inline VALUE
+newobj_slowpath(VALUE klass, VALUE flags, rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, int wb_protected, size_t heap_idx)
+{
+ VALUE obj;
+ unsigned int lev;
+
+ lev = RB_GC_CR_LOCK();
+ {
+ if (RB_UNLIKELY(during_gc || ruby_gc_stressful)) {
+ if (during_gc) {
+ dont_gc_on();
+ during_gc = 0;
+ if (rb_memerror_reentered()) {
+ rb_memerror();
+ }
+ rb_bug("object allocation during garbage collection phase");
+ }
+
+ if (ruby_gc_stressful) {
+ if (!garbage_collect(objspace, GPR_FLAG_NEWOBJ)) {
+ rb_memerror();
+ }
+ }
+ }
+
+ obj = newobj_alloc(objspace, cache, heap_idx, true);
+ newobj_init(klass, flags, wb_protected, objspace, obj);
+ }
+ RB_GC_CR_UNLOCK(lev);
+
+ return obj;
+}
+
+NOINLINE(static VALUE newobj_slowpath_wb_protected(VALUE klass, VALUE flags,
+ rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, size_t heap_idx));
+NOINLINE(static VALUE newobj_slowpath_wb_unprotected(VALUE klass, VALUE flags,
+ rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, size_t heap_idx));
+
+static VALUE
+newobj_slowpath_wb_protected(VALUE klass, VALUE flags, rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, size_t heap_idx)
+{
+ return newobj_slowpath(klass, flags, objspace, cache, TRUE, heap_idx);
+}
+
+static VALUE
+newobj_slowpath_wb_unprotected(VALUE klass, VALUE flags, rb_objspace_t *objspace, rb_ractor_newobj_cache_t *cache, size_t heap_idx)
+{
+ return newobj_slowpath(klass, flags, objspace, cache, FALSE, heap_idx);
+}
+
+VALUE
+rb_gc_impl_new_obj(void *objspace_ptr, void *cache_ptr, VALUE klass, VALUE flags, bool wb_protected, size_t alloc_size)
+{
+ VALUE obj;
+ rb_objspace_t *objspace = objspace_ptr;
+
+ RB_DEBUG_COUNTER_INC(obj_newobj);
+ (void)RB_DEBUG_COUNTER_INC_IF(obj_newobj_wb_unprotected, !wb_protected);
+
+ if (RB_UNLIKELY(stress_to_class)) {
+ if (rb_hash_lookup2(stress_to_class, klass, Qundef) != Qundef) {
+ rb_memerror();
+ }
+ }
+
+ size_t heap_idx = heap_idx_for_size(alloc_size);
+
+ rb_ractor_newobj_cache_t *cache = (rb_ractor_newobj_cache_t *)cache_ptr;
+
+ if (!RB_UNLIKELY(during_gc || ruby_gc_stressful) &&
+ wb_protected) {
+ obj = newobj_alloc(objspace, cache, heap_idx, false);
+ newobj_init(klass, flags, wb_protected, objspace, obj);
+ }
+ else {
+ RB_DEBUG_COUNTER_INC(obj_newobj_slowpath);
+
+ obj = wb_protected ?
+ newobj_slowpath_wb_protected(klass, flags, objspace, cache, heap_idx) :
+ newobj_slowpath_wb_unprotected(klass, flags, objspace, cache, heap_idx);
+ }
+
+ return obj;
+}
+
+static int
+ptr_in_page_body_p(const void *ptr, const void *memb)
+{
+ struct heap_page *page = *(struct heap_page **)memb;
+ uintptr_t p_body = (uintptr_t)page->body;
+
+ if ((uintptr_t)ptr >= p_body) {
+ return (uintptr_t)ptr < (p_body + HEAP_PAGE_SIZE) ? 0 : 1;
+ }
+ else {
+ return -1;
+ }
+}
+
+PUREFUNC(static inline struct heap_page *heap_page_for_ptr(rb_objspace_t *objspace, uintptr_t ptr);)
+static inline struct heap_page *
+heap_page_for_ptr(rb_objspace_t *objspace, uintptr_t ptr)
+{
+ struct heap_page **res;
+
+ if (ptr < (uintptr_t)heap_pages_lomem ||
+ ptr > (uintptr_t)heap_pages_himem) {
+ return NULL;
+ }
+
+ res = bsearch((void *)ptr, rb_darray_ref(objspace->heap_pages.sorted, 0),
+ rb_darray_size(objspace->heap_pages.sorted), sizeof(struct heap_page *),
+ ptr_in_page_body_p);
+
+ if (res) {
+ return *res;
+ }
+ else {
+ return NULL;
+ }
+}
+
+PUREFUNC(static inline bool is_pointer_to_heap(rb_objspace_t *objspace, const void *ptr);)
+static inline bool
+is_pointer_to_heap(rb_objspace_t *objspace, const void *ptr)
+{
+ register uintptr_t p = (uintptr_t)ptr;
+ register struct heap_page *page;
+
+ RB_DEBUG_COUNTER_INC(gc_isptr_trial);
+
+ if (p < heap_pages_lomem || p > heap_pages_himem) return FALSE;
+ RB_DEBUG_COUNTER_INC(gc_isptr_range);
+
+ if (p % sizeof(VALUE) != 0) return FALSE;
+ RB_DEBUG_COUNTER_INC(gc_isptr_align);
+
+ page = heap_page_for_ptr(objspace, (uintptr_t)ptr);
+ if (page) {
+ RB_DEBUG_COUNTER_INC(gc_isptr_maybe);
+ if (heap_page_in_global_empty_pages_pool(objspace, page)) {
+ return FALSE;
+ }
+ else {
+ if (p < page->start) return FALSE;
+ if (p >= page->start + (page->total_slots * page->slot_size)) return FALSE;
+ if ((p - page->start) % page->slot_size != 0) return FALSE;
+
+ return TRUE;
+ }
+ }
+ return FALSE;
+}
+
+bool
+rb_gc_impl_pointer_to_heap_p(void *objspace_ptr, const void *ptr)
+{
+ return is_pointer_to_heap(objspace_ptr, ptr);
+}
+
+#define ZOMBIE_OBJ_KEPT_FLAGS (FL_FINALIZE)
+
+void
+rb_gc_impl_make_zombie(void *objspace_ptr, VALUE obj, void (*dfree)(void *), void *data)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ struct RZombie *zombie = RZOMBIE(obj);
+ zombie->flags = T_ZOMBIE | (zombie->flags & ZOMBIE_OBJ_KEPT_FLAGS);
+ zombie->dfree = dfree;
+ zombie->data = data;
+ VALUE prev, next = heap_pages_deferred_final;
+ do {
+ zombie->next = prev = next;
+ next = RUBY_ATOMIC_VALUE_CAS(heap_pages_deferred_final, prev, obj);
+ } while (next != prev);
+
+ struct heap_page *page = GET_HEAP_PAGE(obj);
+ page->final_slots++;
+ page->heap->final_slots_count++;
+}
+
+typedef int each_obj_callback(void *, void *, size_t, void *);
+typedef int each_page_callback(struct heap_page *, void *);
+
+struct each_obj_data {
+ rb_objspace_t *objspace;
+ bool reenable_incremental;
+
+ each_obj_callback *each_obj_callback;
+ each_page_callback *each_page_callback;
+ void *data;
+
+ struct heap_page **pages[HEAP_COUNT];
+ size_t pages_counts[HEAP_COUNT];
+};
+
+static VALUE
+objspace_each_objects_ensure(VALUE arg)
+{
+ struct each_obj_data *data = (struct each_obj_data *)arg;
+ rb_objspace_t *objspace = data->objspace;
+
+ /* Reenable incremental GC */
+ if (data->reenable_incremental) {
+ objspace->flags.dont_incremental = FALSE;
+ }
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ struct heap_page **pages = data->pages[i];
+ free(pages);
+ }
+
+ return Qnil;
+}
+
+static VALUE
+objspace_each_objects_try(VALUE arg)
+{
+ struct each_obj_data *data = (struct each_obj_data *)arg;
+ rb_objspace_t *objspace = data->objspace;
+
+ /* Copy pages from all heaps to their respective buffers. */
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ size_t size = heap->total_pages * sizeof(struct heap_page *);
+
+ struct heap_page **pages = malloc(size);
+ if (!pages) rb_memerror();
+
+ /* Set up pages buffer by iterating over all pages in the current eden
+ * heap. This will be a snapshot of the state of the heap before we
+ * call the callback over each page that exists in this buffer. Thus it
+ * is safe for the callback to allocate objects without possibly entering
+ * an infinite loop. */
+ struct heap_page *page = 0;
+ size_t pages_count = 0;
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ pages[pages_count] = page;
+ pages_count++;
+ }
+ data->pages[i] = pages;
+ data->pages_counts[i] = pages_count;
+ GC_ASSERT(pages_count == heap->total_pages);
+ }
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ size_t pages_count = data->pages_counts[i];
+ struct heap_page **pages = data->pages[i];
+
+ struct heap_page *page = ccan_list_top(&heap->pages, struct heap_page, page_node);
+ for (size_t i = 0; i < pages_count; i++) {
+ /* If we have reached the end of the linked list then there are no
+ * more pages, so break. */
+ if (page == NULL) break;
+
+ /* If this page does not match the one in the buffer, then move to
+ * the next page in the buffer. */
+ if (pages[i] != page) continue;
+
+ uintptr_t pstart = (uintptr_t)page->start;
+ uintptr_t pend = pstart + (page->total_slots * heap->slot_size);
+
+ if (data->each_obj_callback &&
+ (*data->each_obj_callback)((void *)pstart, (void *)pend, heap->slot_size, data->data)) {
+ break;
+ }
+ if (data->each_page_callback &&
+ (*data->each_page_callback)(page, data->data)) {
+ break;
+ }
+
+ page = ccan_list_next(&heap->pages, page, page_node);
+ }
+ }
+
+ return Qnil;
+}
+
+static void
+objspace_each_exec(bool protected, struct each_obj_data *each_obj_data)
+{
+ /* Disable incremental GC */
+ rb_objspace_t *objspace = each_obj_data->objspace;
+ bool reenable_incremental = FALSE;
+ if (protected) {
+ reenable_incremental = !objspace->flags.dont_incremental;
+
+ gc_rest(objspace);
+ objspace->flags.dont_incremental = TRUE;
+ }
+
+ each_obj_data->reenable_incremental = reenable_incremental;
+ memset(&each_obj_data->pages, 0, sizeof(each_obj_data->pages));
+ memset(&each_obj_data->pages_counts, 0, sizeof(each_obj_data->pages_counts));
+ rb_ensure(objspace_each_objects_try, (VALUE)each_obj_data,
+ objspace_each_objects_ensure, (VALUE)each_obj_data);
+}
+
+static void
+objspace_each_objects(rb_objspace_t *objspace, each_obj_callback *callback, void *data, bool protected)
+{
+ struct each_obj_data each_obj_data = {
+ .objspace = objspace,
+ .each_obj_callback = callback,
+ .each_page_callback = NULL,
+ .data = data,
+ };
+ objspace_each_exec(protected, &each_obj_data);
+}
+
+void
+rb_gc_impl_each_objects(void *objspace_ptr, each_obj_callback *callback, void *data)
+{
+ objspace_each_objects(objspace_ptr, callback, data, TRUE);
+}
+
+#if GC_CAN_COMPILE_COMPACTION
+static void
+objspace_each_pages(rb_objspace_t *objspace, each_page_callback *callback, void *data, bool protected)
+{
+ struct each_obj_data each_obj_data = {
+ .objspace = objspace,
+ .each_obj_callback = NULL,
+ .each_page_callback = callback,
+ .data = data,
+ };
+ objspace_each_exec(protected, &each_obj_data);
+}
+#endif
+
+VALUE
+rb_gc_impl_define_finalizer(void *objspace_ptr, VALUE obj, VALUE block)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ VALUE table;
+ st_data_t data;
+
+ GC_ASSERT(!OBJ_FROZEN(obj));
+
+ RBASIC(obj)->flags |= FL_FINALIZE;
+
+ unsigned int lev = RB_GC_VM_LOCK();
+
+ if (st_lookup(finalizer_table, obj, &data)) {
+ table = (VALUE)data;
+ VALUE dup_table = rb_ary_dup(table);
+
+ RB_GC_VM_UNLOCK(lev);
+ /* avoid duplicate block, table is usually small */
+ {
+ long len = RARRAY_LEN(table);
+ long i;
+
+ for (i = 0; i < len; i++) {
+ VALUE recv = RARRAY_AREF(dup_table, i);
+ if (rb_equal(recv, block)) { // can't be called with VM lock held
+ return recv;
+ }
+ }
+ }
+ lev = RB_GC_VM_LOCK();
+ RB_GC_GUARD(dup_table);
+
+ rb_ary_push(table, block);
+ }
+ else {
+ table = rb_ary_new3(2, rb_obj_id(obj), block);
+ rb_obj_hide(table);
+ st_add_direct(finalizer_table, obj, table);
+ }
+
+ RB_GC_VM_UNLOCK(lev);
+
+ return block;
+}
+
+void
+rb_gc_impl_undefine_finalizer(void *objspace_ptr, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ GC_ASSERT(!OBJ_FROZEN(obj));
+
+ st_data_t data = obj;
+
+ int lev = RB_GC_VM_LOCK();
+ st_delete(finalizer_table, &data, 0);
+ RB_GC_VM_UNLOCK(lev);
+
+ FL_UNSET(obj, FL_FINALIZE);
+}
+
+void
+rb_gc_impl_copy_finalizer(void *objspace_ptr, VALUE dest, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ VALUE table;
+ st_data_t data;
+
+ if (!FL_TEST(obj, FL_FINALIZE)) return;
+
+ int lev = RB_GC_VM_LOCK();
+ if (RB_LIKELY(st_lookup(finalizer_table, obj, &data))) {
+ table = rb_ary_dup((VALUE)data);
+ RARRAY_ASET(table, 0, rb_obj_id(dest));
+ st_insert(finalizer_table, dest, table);
+ FL_SET(dest, FL_FINALIZE);
+ }
+ else {
+ rb_bug("rb_gc_copy_finalizer: FL_FINALIZE set but not found in finalizer_table: %s", rb_obj_info(obj));
+ }
+ RB_GC_VM_UNLOCK(lev);
+}
+
+static VALUE
+get_final(long i, void *data)
+{
+ VALUE table = (VALUE)data;
+
+ return RARRAY_AREF(table, i + 1);
+}
+
+static unsigned int
+run_final(rb_objspace_t *objspace, VALUE zombie, unsigned int lev)
+{
+ if (RZOMBIE(zombie)->dfree) {
+ RZOMBIE(zombie)->dfree(RZOMBIE(zombie)->data);
+ }
+
+ st_data_t key = (st_data_t)zombie;
+ if (FL_TEST_RAW(zombie, FL_FINALIZE)) {
+ FL_UNSET(zombie, FL_FINALIZE);
+ st_data_t table;
+ if (st_delete(finalizer_table, &key, &table)) {
+ RB_GC_VM_UNLOCK(lev);
+ rb_gc_run_obj_finalizer(RARRAY_AREF(table, 0), RARRAY_LEN(table) - 1, get_final, (void *)table);
+ lev = RB_GC_VM_LOCK();
+ }
+ else {
+ rb_bug("FL_FINALIZE flag is set, but finalizers are not found");
+ }
+ }
+ else {
+ GC_ASSERT(!st_lookup(finalizer_table, key, NULL));
+ }
+ return lev;
+}
+
+static void
+finalize_list(rb_objspace_t *objspace, VALUE zombie)
+{
+ while (zombie) {
+ VALUE next_zombie;
+ struct heap_page *page;
+ rb_asan_unpoison_object(zombie, false);
+ next_zombie = RZOMBIE(zombie)->next;
+ page = GET_HEAP_PAGE(zombie);
+
+ unsigned int lev = RB_GC_VM_LOCK();
+
+ lev = run_final(objspace, zombie, lev);
+ {
+ GC_ASSERT(BUILTIN_TYPE(zombie) == T_ZOMBIE);
+ GC_ASSERT(page->heap->final_slots_count > 0);
+ GC_ASSERT(page->final_slots > 0);
+
+ page->heap->final_slots_count--;
+ page->final_slots--;
+ page->free_slots++;
+ RVALUE_AGE_SET_BITMAP(zombie, 0);
+ heap_page_add_freeobj(objspace, page, zombie);
+ page->heap->total_freed_objects++;
+ }
+ RB_GC_VM_UNLOCK(lev);
+
+ zombie = next_zombie;
+ }
+}
+
+static void
+finalize_deferred_heap_pages(rb_objspace_t *objspace)
+{
+ VALUE zombie;
+ while ((zombie = RUBY_ATOMIC_VALUE_EXCHANGE(heap_pages_deferred_final, 0)) != 0) {
+ finalize_list(objspace, zombie);
+ }
+}
+
+static void
+finalize_deferred(rb_objspace_t *objspace)
+{
+ rb_gc_set_pending_interrupt();
+ finalize_deferred_heap_pages(objspace);
+ rb_gc_unset_pending_interrupt();
+}
+
+static void
+gc_finalize_deferred(void *dmy)
+{
+ rb_objspace_t *objspace = dmy;
+ if (RUBY_ATOMIC_EXCHANGE(finalizing, 1)) return;
+
+ finalize_deferred(objspace);
+ RUBY_ATOMIC_SET(finalizing, 0);
+}
+
+static void
+gc_finalize_deferred_register(rb_objspace_t *objspace)
+{
+ /* will enqueue a call to gc_finalize_deferred */
+ rb_postponed_job_trigger(objspace->finalize_deferred_pjob);
+}
+
+static int pop_mark_stack(mark_stack_t *stack, VALUE *data);
+
+static void
+gc_abort(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (is_incremental_marking(objspace)) {
+ /* Remove all objects from the mark stack. */
+ VALUE obj;
+ while (pop_mark_stack(&objspace->mark_stack, &obj));
+
+ objspace->flags.during_incremental_marking = FALSE;
+ }
+
+ if (is_lazy_sweeping(objspace)) {
+ objspace->sweeping_heap_count = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+
+ heap->sweeping_page = NULL;
+ struct heap_page *page = NULL;
+
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ page->flags.before_sweep = false;
+ }
+ }
+ }
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ rgengc_mark_and_rememberset_clear(objspace, heap);
+ }
+
+ gc_mode_set(objspace, gc_mode_none);
+}
+
+void
+rb_gc_impl_shutdown_free_objects(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ for (size_t i = 0; i < rb_darray_size(objspace->heap_pages.sorted); i++) {
+ struct heap_page *page = rb_darray_get(objspace->heap_pages.sorted, i);
+ short stride = page->slot_size;
+
+ uintptr_t p = (uintptr_t)page->start;
+ uintptr_t pend = p + page->total_slots * stride;
+ for (; p < pend; p += stride) {
+ VALUE vp = (VALUE)p;
+ asan_unpoisoning_object(vp) {
+ if (RB_BUILTIN_TYPE(vp) != T_NONE) {
+ rb_gc_obj_free_vm_weak_references(vp);
+ if (rb_gc_obj_free(objspace, vp)) {
+ RBASIC(vp)->flags = 0;
+ }
+ }
+ }
+ }
+ }
+}
+
+static int
+rb_gc_impl_shutdown_call_finalizer_i(st_data_t key, st_data_t val, st_data_t _data)
+{
+ VALUE obj = (VALUE)key;
+ VALUE table = (VALUE)val;
+
+ GC_ASSERT(RB_FL_TEST(obj, FL_FINALIZE));
+ GC_ASSERT(RB_BUILTIN_TYPE(val) == T_ARRAY);
+
+ rb_gc_run_obj_finalizer(RARRAY_AREF(table, 0), RARRAY_LEN(table) - 1, get_final, (void *)table);
+
+ FL_UNSET(obj, FL_FINALIZE);
+
+ return ST_DELETE;
+}
+
+void
+rb_gc_impl_shutdown_call_finalizer(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+#if RGENGC_CHECK_MODE >= 2
+ gc_verify_internal_consistency(objspace);
+#endif
+
+ /* prohibit incremental GC */
+ objspace->flags.dont_incremental = 1;
+
+ if (RUBY_ATOMIC_EXCHANGE(finalizing, 1)) {
+ /* Abort incremental marking and lazy sweeping to speed up shutdown. */
+ gc_abort(objspace);
+ dont_gc_on();
+ return;
+ }
+
+ while (finalizer_table->num_entries) {
+ st_foreach(finalizer_table, rb_gc_impl_shutdown_call_finalizer_i, 0);
+ }
+
+ /* run finalizers */
+ finalize_deferred(objspace);
+ GC_ASSERT(heap_pages_deferred_final == 0);
+
+ /* Abort incremental marking and lazy sweeping to speed up shutdown. */
+ gc_abort(objspace);
+
+ /* prohibit GC because force T_DATA finalizers can break an object graph consistency */
+ dont_gc_on();
+
+ /* running data/file finalizers are part of garbage collection */
+ unsigned int lock_lev;
+ gc_enter(objspace, gc_enter_event_finalizer, &lock_lev);
+
+ /* run data/file object's finalizers */
+ for (size_t i = 0; i < rb_darray_size(objspace->heap_pages.sorted); i++) {
+ struct heap_page *page = rb_darray_get(objspace->heap_pages.sorted, i);
+ short stride = page->slot_size;
+
+ uintptr_t p = (uintptr_t)page->start;
+ uintptr_t pend = p + page->total_slots * stride;
+ for (; p < pend; p += stride) {
+ VALUE vp = (VALUE)p;
+ asan_unpoisoning_object(vp) {
+ if (rb_gc_shutdown_call_finalizer_p(vp)) {
+ rb_gc_obj_free_vm_weak_references(vp);
+ if (rb_gc_obj_free(objspace, vp)) {
+ RBASIC(vp)->flags = 0;
+ }
+ }
+ }
+ }
+ }
+
+ gc_exit(objspace, gc_enter_event_finalizer, &lock_lev);
+
+ finalize_deferred_heap_pages(objspace);
+
+ st_free_table(finalizer_table);
+ finalizer_table = 0;
+ RUBY_ATOMIC_SET(finalizing, 0);
+}
+
+void
+rb_gc_impl_each_object(void *objspace_ptr, void (*func)(VALUE obj, void *data), void *data)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ for (size_t i = 0; i < rb_darray_size(objspace->heap_pages.sorted); i++) {
+ struct heap_page *page = rb_darray_get(objspace->heap_pages.sorted, i);
+ short stride = page->slot_size;
+
+ uintptr_t p = (uintptr_t)page->start;
+ uintptr_t pend = p + page->total_slots * stride;
+ for (; p < pend; p += stride) {
+ VALUE obj = (VALUE)p;
+
+ asan_unpoisoning_object(obj) {
+ func(obj, data);
+ }
+ }
+ }
+}
+
+/*
+ ------------------------ Garbage Collection ------------------------
+*/
+
+/* Sweeping */
+
+static size_t
+objspace_available_slots(rb_objspace_t *objspace)
+{
+ size_t total_slots = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ total_slots += heap->total_slots;
+ }
+ return total_slots;
+}
+
+static size_t
+objspace_live_slots(rb_objspace_t *objspace)
+{
+ return total_allocated_objects(objspace) - total_freed_objects(objspace) - total_final_slots_count(objspace);
+}
+
+static size_t
+objspace_free_slots(rb_objspace_t *objspace)
+{
+ return objspace_available_slots(objspace) - objspace_live_slots(objspace) - total_final_slots_count(objspace);
+}
+
+static void
+gc_setup_mark_bits(struct heap_page *page)
+{
+ /* copy oldgen bitmap to mark bitmap */
+ memcpy(&page->mark_bits[0], &page->uncollectible_bits[0], HEAP_PAGE_BITMAP_SIZE);
+}
+
+static int gc_is_moveable_obj(rb_objspace_t *objspace, VALUE obj);
+static VALUE gc_move(rb_objspace_t *objspace, VALUE scan, VALUE free, struct heap_page *src_page, struct heap_page *dest_page);
+
+#if defined(_WIN32)
+enum {HEAP_PAGE_LOCK = PAGE_NOACCESS, HEAP_PAGE_UNLOCK = PAGE_READWRITE};
+
+static BOOL
+protect_page_body(struct heap_page_body *body, DWORD protect)
+{
+ DWORD old_protect;
+ return VirtualProtect(body, HEAP_PAGE_SIZE, protect, &old_protect) != 0;
+}
+#elif defined(__wasi__)
+// wasi-libc's mprotect emulation does not support PROT_NONE
+enum {HEAP_PAGE_LOCK, HEAP_PAGE_UNLOCK};
+#define protect_page_body(body, protect) 1
+#else
+enum {HEAP_PAGE_LOCK = PROT_NONE, HEAP_PAGE_UNLOCK = PROT_READ | PROT_WRITE};
+#define protect_page_body(body, protect) !mprotect((body), HEAP_PAGE_SIZE, (protect))
+#endif
+
+static void
+lock_page_body(rb_objspace_t *objspace, struct heap_page_body *body)
+{
+ if (!protect_page_body(body, HEAP_PAGE_LOCK)) {
+ rb_bug("Couldn't protect page %p, errno: %s", (void *)body, strerror(errno));
+ }
+ else {
+ gc_report(5, objspace, "Protecting page in move %p\n", (void *)body);
+ }
+}
+
+static void
+unlock_page_body(rb_objspace_t *objspace, struct heap_page_body *body)
+{
+ if (!protect_page_body(body, HEAP_PAGE_UNLOCK)) {
+ rb_bug("Couldn't unprotect page %p, errno: %s", (void *)body, strerror(errno));
+ }
+ else {
+ gc_report(5, objspace, "Unprotecting page in move %p\n", (void *)body);
+ }
+}
+
+static bool
+try_move(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *free_page, VALUE src)
+{
+ GC_ASSERT(gc_is_moveable_obj(objspace, src));
+
+ struct heap_page *src_page = GET_HEAP_PAGE(src);
+ if (!free_page) {
+ return false;
+ }
+
+ /* We should return true if either src is successfully moved, or src is
+ * unmoveable. A false return will cause the sweeping cursor to be
+ * incremented to the next page, and src will attempt to move again */
+ GC_ASSERT(RVALUE_MARKED(objspace, src));
+
+ asan_unlock_freelist(free_page);
+ VALUE dest = (VALUE)free_page->freelist;
+ asan_lock_freelist(free_page);
+ if (dest) {
+ rb_asan_unpoison_object(dest, false);
+ }
+ else {
+ /* if we can't get something from the freelist then the page must be
+ * full */
+ return false;
+ }
+ asan_unlock_freelist(free_page);
+ free_page->freelist = ((struct free_slot *)dest)->next;
+ asan_lock_freelist(free_page);
+
+ GC_ASSERT(RB_BUILTIN_TYPE(dest) == T_NONE);
+
+ if (src_page->slot_size > free_page->slot_size) {
+ objspace->rcompactor.moved_down_count_table[BUILTIN_TYPE(src)]++;
+ }
+ else if (free_page->slot_size > src_page->slot_size) {
+ objspace->rcompactor.moved_up_count_table[BUILTIN_TYPE(src)]++;
+ }
+ objspace->rcompactor.moved_count_table[BUILTIN_TYPE(src)]++;
+ objspace->rcompactor.total_moved++;
+
+ gc_move(objspace, src, dest, src_page, free_page);
+ gc_pin(objspace, src);
+ free_page->free_slots--;
+
+ return true;
+}
+
+static void
+gc_unprotect_pages(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ struct heap_page *cursor = heap->compact_cursor;
+
+ while (cursor) {
+ unlock_page_body(objspace, cursor->body);
+ cursor = ccan_list_next(&heap->pages, cursor, page_node);
+ }
+}
+
+static void gc_update_references(rb_objspace_t *objspace);
+#if GC_CAN_COMPILE_COMPACTION
+static void invalidate_moved_page(rb_objspace_t *objspace, struct heap_page *page);
+#endif
+
+#if defined(__MINGW32__) || defined(_WIN32)
+# define GC_COMPACTION_SUPPORTED 1
+#else
+/* If not MinGW, Windows, or does not have mmap, we cannot use mprotect for
+ * the read barrier, so we must disable compaction. */
+# define GC_COMPACTION_SUPPORTED (GC_CAN_COMPILE_COMPACTION && HEAP_PAGE_ALLOC_USE_MMAP)
+#endif
+
+#if GC_CAN_COMPILE_COMPACTION
+static void
+read_barrier_handler(uintptr_t address)
+{
+ rb_objspace_t *objspace = (rb_objspace_t *)rb_gc_get_objspace();
+
+ struct heap_page_body *page_body = GET_PAGE_BODY(address);
+
+ /* If the page_body is NULL, then mprotect cannot handle it and will crash
+ * with "Cannot allocate memory". */
+ if (page_body == NULL) {
+ rb_bug("read_barrier_handler: segmentation fault at %p", (void *)address);
+ }
+
+ int lev = RB_GC_VM_LOCK();
+ {
+ unlock_page_body(objspace, page_body);
+
+ objspace->profile.read_barrier_faults++;
+
+ invalidate_moved_page(objspace, GET_HEAP_PAGE(address));
+ }
+ RB_GC_VM_UNLOCK(lev);
+}
+#endif
+
+#if !GC_CAN_COMPILE_COMPACTION
+static void
+uninstall_handlers(void)
+{
+ /* no-op */
+}
+
+static void
+install_handlers(void)
+{
+ /* no-op */
+}
+#elif defined(_WIN32)
+static LPTOP_LEVEL_EXCEPTION_FILTER old_handler;
+typedef void (*signal_handler)(int);
+static signal_handler old_sigsegv_handler;
+
+static LONG WINAPI
+read_barrier_signal(EXCEPTION_POINTERS *info)
+{
+ /* EXCEPTION_ACCESS_VIOLATION is what's raised by access to protected pages */
+ if (info->ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION) {
+ /* > The second array element specifies the virtual address of the inaccessible data.
+ * https://docs.microsoft.com/en-us/windows/win32/api/winnt/ns-winnt-exception_record
+ *
+ * Use this address to invalidate the page */
+ read_barrier_handler((uintptr_t)info->ExceptionRecord->ExceptionInformation[1]);
+ return EXCEPTION_CONTINUE_EXECUTION;
+ }
+ else {
+ return EXCEPTION_CONTINUE_SEARCH;
+ }
+}
+
+static void
+uninstall_handlers(void)
+{
+ signal(SIGSEGV, old_sigsegv_handler);
+ SetUnhandledExceptionFilter(old_handler);
+}
+
+static void
+install_handlers(void)
+{
+ /* Remove SEGV handler so that the Unhandled Exception Filter handles it */
+ old_sigsegv_handler = signal(SIGSEGV, NULL);
+ /* Unhandled Exception Filter has access to the violation address similar
+ * to si_addr from sigaction */
+ old_handler = SetUnhandledExceptionFilter(read_barrier_signal);
+}
+#else
+static struct sigaction old_sigbus_handler;
+static struct sigaction old_sigsegv_handler;
+
+#ifdef HAVE_MACH_TASK_EXCEPTION_PORTS
+static exception_mask_t old_exception_masks[32];
+static mach_port_t old_exception_ports[32];
+static exception_behavior_t old_exception_behaviors[32];
+static thread_state_flavor_t old_exception_flavors[32];
+static mach_msg_type_number_t old_exception_count;
+
+static void
+disable_mach_bad_access_exc(void)
+{
+ old_exception_count = sizeof(old_exception_masks) / sizeof(old_exception_masks[0]);
+ task_swap_exception_ports(
+ mach_task_self(), EXC_MASK_BAD_ACCESS,
+ MACH_PORT_NULL, EXCEPTION_DEFAULT, 0,
+ old_exception_masks, &old_exception_count,
+ old_exception_ports, old_exception_behaviors, old_exception_flavors
+ );
+}
+
+static void
+restore_mach_bad_access_exc(void)
+{
+ for (mach_msg_type_number_t i = 0; i < old_exception_count; i++) {
+ task_set_exception_ports(
+ mach_task_self(),
+ old_exception_masks[i], old_exception_ports[i],
+ old_exception_behaviors[i], old_exception_flavors[i]
+ );
+ }
+}
+#endif
+
+static void
+read_barrier_signal(int sig, siginfo_t *info, void *data)
+{
+ // setup SEGV/BUS handlers for errors
+ struct sigaction prev_sigbus, prev_sigsegv;
+ sigaction(SIGBUS, &old_sigbus_handler, &prev_sigbus);
+ sigaction(SIGSEGV, &old_sigsegv_handler, &prev_sigsegv);
+
+ // enable SIGBUS/SEGV
+ sigset_t set, prev_set;
+ sigemptyset(&set);
+ sigaddset(&set, SIGBUS);
+ sigaddset(&set, SIGSEGV);
+ sigprocmask(SIG_UNBLOCK, &set, &prev_set);
+#ifdef HAVE_MACH_TASK_EXCEPTION_PORTS
+ disable_mach_bad_access_exc();
+#endif
+ // run handler
+ read_barrier_handler((uintptr_t)info->si_addr);
+
+ // reset SEGV/BUS handlers
+#ifdef HAVE_MACH_TASK_EXCEPTION_PORTS
+ restore_mach_bad_access_exc();
+#endif
+ sigaction(SIGBUS, &prev_sigbus, NULL);
+ sigaction(SIGSEGV, &prev_sigsegv, NULL);
+ sigprocmask(SIG_SETMASK, &prev_set, NULL);
+}
+
+static void
+uninstall_handlers(void)
+{
+#ifdef HAVE_MACH_TASK_EXCEPTION_PORTS
+ restore_mach_bad_access_exc();
+#endif
+ sigaction(SIGBUS, &old_sigbus_handler, NULL);
+ sigaction(SIGSEGV, &old_sigsegv_handler, NULL);
+}
+
+static void
+install_handlers(void)
+{
+ struct sigaction action;
+ memset(&action, 0, sizeof(struct sigaction));
+ sigemptyset(&action.sa_mask);
+ action.sa_sigaction = read_barrier_signal;
+ action.sa_flags = SA_SIGINFO | SA_ONSTACK;
+
+ sigaction(SIGBUS, &action, &old_sigbus_handler);
+ sigaction(SIGSEGV, &action, &old_sigsegv_handler);
+#ifdef HAVE_MACH_TASK_EXCEPTION_PORTS
+ disable_mach_bad_access_exc();
+#endif
+}
+#endif
+
+static void
+gc_compact_finish(rb_objspace_t *objspace)
+{
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ gc_unprotect_pages(objspace, heap);
+ }
+
+ uninstall_handlers();
+
+ gc_update_references(objspace);
+ objspace->profile.compact_count++;
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ heap->compact_cursor = NULL;
+ heap->free_pages = NULL;
+ heap->compact_cursor_index = 0;
+ }
+
+ if (gc_prof_enabled(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+ record->moved_objects = objspace->rcompactor.total_moved - record->moved_objects;
+ }
+ objspace->flags.during_compacting = FALSE;
+}
+
+struct gc_sweep_context {
+ struct heap_page *page;
+ int final_slots;
+ int freed_slots;
+ int empty_slots;
+};
+
+static inline void
+gc_sweep_plane(rb_objspace_t *objspace, rb_heap_t *heap, uintptr_t p, bits_t bitset, struct gc_sweep_context *ctx)
+{
+ struct heap_page *sweep_page = ctx->page;
+ short slot_size = sweep_page->slot_size;
+
+ do {
+ VALUE vp = (VALUE)p;
+ GC_ASSERT(vp % sizeof(VALUE) == 0);
+
+ rb_asan_unpoison_object(vp, false);
+ if (bitset & 1) {
+ switch (BUILTIN_TYPE(vp)) {
+ case T_MOVED:
+ if (objspace->flags.during_compacting) {
+ /* The sweep cursor shouldn't have made it to any
+ * T_MOVED slots while the compact flag is enabled.
+ * The sweep cursor and compact cursor move in
+ * opposite directions, and when they meet references will
+ * get updated and "during_compacting" should get disabled */
+ rb_bug("T_MOVED shouldn't be seen until compaction is finished");
+ }
+ gc_report(3, objspace, "page_sweep: %s is added to freelist\n", rb_obj_info(vp));
+ ctx->empty_slots++;
+ heap_page_add_freeobj(objspace, sweep_page, vp);
+ break;
+ case T_ZOMBIE:
+ /* already counted */
+ break;
+ case T_NONE:
+ ctx->empty_slots++; /* already freed */
+ break;
+
+ default:
+#if RGENGC_CHECK_MODE
+ if (!is_full_marking(objspace)) {
+ if (RVALUE_OLD_P(objspace, vp)) rb_bug("page_sweep: %p - old while minor GC.", (void *)p);
+ if (RVALUE_REMEMBERED(objspace, vp)) rb_bug("page_sweep: %p - remembered.", (void *)p);
+ }
+#endif
+
+#if RGENGC_CHECK_MODE
+#define CHECK(x) if (x(objspace, vp) != FALSE) rb_bug("obj_free: " #x "(%s) != FALSE", rb_obj_info(vp))
+ CHECK(RVALUE_WB_UNPROTECTED);
+ CHECK(RVALUE_MARKED);
+ CHECK(RVALUE_MARKING);
+ CHECK(RVALUE_UNCOLLECTIBLE);
+#undef CHECK
+#endif
+
+ if (!rb_gc_obj_needs_cleanup_p(vp)) {
+ if (RB_UNLIKELY(objspace->hook_events & RUBY_INTERNAL_EVENT_FREEOBJ)) {
+ rb_gc_event_hook(vp, RUBY_INTERNAL_EVENT_FREEOBJ);
+ }
+
+ (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)p, slot_size);
+ heap_page_add_freeobj(objspace, sweep_page, vp);
+ gc_report(3, objspace, "page_sweep: %s (fast path) added to freelist\n", rb_obj_info(vp));
+ ctx->freed_slots++;
+ }
+ else {
+ gc_report(2, objspace, "page_sweep: free %p\n", (void *)p);
+
+ rb_gc_event_hook(vp, RUBY_INTERNAL_EVENT_FREEOBJ);
+
+ rb_gc_obj_free_vm_weak_references(vp);
+ if (rb_gc_obj_free(objspace, vp)) {
+ (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)p, slot_size);
+ heap_page_add_freeobj(objspace, sweep_page, vp);
+ gc_report(3, objspace, "page_sweep: %s is added to freelist\n", rb_obj_info(vp));
+ ctx->freed_slots++;
+ }
+ else {
+ ctx->final_slots++;
+ }
+ }
+ break;
+ }
+ }
+ p += slot_size;
+ bitset >>= 1;
+ } while (bitset);
+}
+
+static inline void
+gc_sweep_page(rb_objspace_t *objspace, rb_heap_t *heap, struct gc_sweep_context *ctx)
+{
+ struct heap_page *sweep_page = ctx->page;
+ GC_ASSERT(sweep_page->heap == heap);
+
+ uintptr_t p;
+ bits_t *bits, bitset;
+
+ gc_report(2, objspace, "page_sweep: start.\n");
+
+#if RGENGC_CHECK_MODE
+ if (!objspace->flags.immediate_sweep) {
+ GC_ASSERT(sweep_page->flags.before_sweep == TRUE);
+ }
+#endif
+ sweep_page->flags.before_sweep = FALSE;
+ sweep_page->free_slots = 0;
+
+ p = (uintptr_t)sweep_page->start;
+ bits = sweep_page->mark_bits;
+ short slot_size = sweep_page->slot_size;
+ int total_slots = sweep_page->total_slots;
+ int bitmap_plane_count = CEILDIV(total_slots, BITS_BITLENGTH);
+
+ int out_of_range_bits = total_slots % BITS_BITLENGTH;
+ if (out_of_range_bits != 0) {
+ bits[bitmap_plane_count - 1] |= ~(((bits_t)1 << out_of_range_bits) - 1);
+ }
+
+ // Clear wb_unprotected and age bits for all unmarked slots
+ {
+ bits_t *wb_unprotected_bits = sweep_page->wb_unprotected_bits;
+ bits_t *age_bits = sweep_page->age_bits;
+ for (int i = 0; i < bitmap_plane_count; i++) {
+ bits_t unmarked = ~bits[i];
+ wb_unprotected_bits[i] &= ~unmarked;
+ age_bits[i * 2] &= ~unmarked;
+ age_bits[i * 2 + 1] &= ~unmarked;
+ }
+ }
+
+ for (int i = 0; i < bitmap_plane_count; i++) {
+ bitset = ~bits[i];
+ if (bitset) {
+ gc_sweep_plane(objspace, heap, p, bitset, ctx);
+ }
+ p += BITS_BITLENGTH * slot_size;
+ }
+
+ if (!heap->compact_cursor) {
+ gc_setup_mark_bits(sweep_page);
+ }
+
+#if GC_PROFILE_MORE_DETAIL
+ if (gc_prof_enabled(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+ record->removing_objects += ctx->final_slots + ctx->freed_slots;
+ record->empty_objects += ctx->empty_slots;
+ }
+#endif
+ if (0) fprintf(stderr, "gc_sweep_page(%"PRIdSIZE"): total_slots: %d, freed_slots: %d, empty_slots: %d, final_slots: %d\n",
+ rb_gc_count(),
+ sweep_page->total_slots,
+ ctx->freed_slots, ctx->empty_slots, ctx->final_slots);
+
+ sweep_page->free_slots += ctx->freed_slots + ctx->empty_slots;
+ sweep_page->heap->total_freed_objects += ctx->freed_slots;
+
+ if (heap_pages_deferred_final && !finalizing) {
+ gc_finalize_deferred_register(objspace);
+ }
+
+#if RGENGC_CHECK_MODE
+ short freelist_len = 0;
+ asan_unlock_freelist(sweep_page);
+ struct free_slot *ptr = sweep_page->freelist;
+ while (ptr) {
+ freelist_len++;
+ rb_asan_unpoison_object((VALUE)ptr, false);
+ struct free_slot *next = ptr->next;
+ rb_asan_poison_object((VALUE)ptr);
+ ptr = next;
+ }
+ asan_lock_freelist(sweep_page);
+ if (freelist_len != sweep_page->free_slots) {
+ rb_bug("inconsistent freelist length: expected %d but was %d", sweep_page->free_slots, freelist_len);
+ }
+#endif
+
+ gc_report(2, objspace, "page_sweep: end.\n");
+}
+
+static const char *
+gc_mode_name(enum gc_mode mode)
+{
+ switch (mode) {
+ case gc_mode_none: return "none";
+ case gc_mode_marking: return "marking";
+ case gc_mode_sweeping: return "sweeping";
+ case gc_mode_compacting: return "compacting";
+ default: rb_bug("gc_mode_name: unknown mode: %d", (int)mode);
+ }
+}
+
+static void
+gc_mode_transition(rb_objspace_t *objspace, enum gc_mode mode)
+{
+#if RGENGC_CHECK_MODE
+ enum gc_mode prev_mode = gc_mode(objspace);
+ switch (prev_mode) {
+ case gc_mode_none: GC_ASSERT(mode == gc_mode_marking); break;
+ case gc_mode_marking: GC_ASSERT(mode == gc_mode_sweeping); break;
+ case gc_mode_sweeping: GC_ASSERT(mode == gc_mode_none || mode == gc_mode_compacting); break;
+ case gc_mode_compacting: GC_ASSERT(mode == gc_mode_none); break;
+ }
+#endif
+ if (0) fprintf(stderr, "gc_mode_transition: %s->%s\n", gc_mode_name(gc_mode(objspace)), gc_mode_name(mode));
+ gc_mode_set(objspace, mode);
+}
+
+static void
+heap_page_freelist_append(struct heap_page *page, struct free_slot *freelist)
+{
+ if (freelist) {
+ asan_unlock_freelist(page);
+ if (page->freelist) {
+ struct free_slot *p = page->freelist;
+ rb_asan_unpoison_object((VALUE)p, false);
+ while (p->next) {
+ struct free_slot *prev = p;
+ p = p->next;
+ rb_asan_poison_object((VALUE)prev);
+ rb_asan_unpoison_object((VALUE)p, false);
+ }
+ p->next = freelist;
+ rb_asan_poison_object((VALUE)p);
+ }
+ else {
+ page->freelist = freelist;
+ }
+ asan_lock_freelist(page);
+ }
+}
+
+static void
+gc_sweep_start_heap(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ heap->sweeping_page = ccan_list_top(&heap->pages, struct heap_page, page_node);
+ if (heap->sweeping_page) {
+ objspace->sweeping_heap_count++;
+ }
+ heap->free_pages = NULL;
+ heap->pooled_pages = NULL;
+ if (!objspace->flags.immediate_sweep) {
+ struct heap_page *page = NULL;
+
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ page->flags.before_sweep = TRUE;
+ }
+ }
+}
+
+#if defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ == 4
+__attribute__((noinline))
+#endif
+
+#if GC_CAN_COMPILE_COMPACTION
+static void gc_sort_heap_by_compare_func(rb_objspace_t *objspace, gc_compact_compare_func compare_func);
+static int compare_pinned_slots(const void *left, const void *right, void *d);
+#endif
+
+static void
+gc_ractor_newobj_cache_clear(void *c, void *data)
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+ rb_ractor_newobj_cache_t *newobj_cache = c;
+
+ newobj_cache->incremental_mark_step_allocated_slots = 0;
+
+ for (size_t heap_idx = 0; heap_idx < HEAP_COUNT; heap_idx++) {
+
+ rb_ractor_newobj_heap_cache_t *cache = &newobj_cache->heap_caches[heap_idx];
+
+ rb_heap_t *heap = &heaps[heap_idx];
+ RUBY_ATOMIC_SIZE_ADD(heap->total_allocated_objects, cache->allocated_objects_count);
+ cache->allocated_objects_count = 0;
+
+ struct heap_page *page = cache->using_page;
+ struct free_slot *freelist = cache->freelist;
+ RUBY_DEBUG_LOG("ractor using_page:%p freelist:%p", (void *)page, (void *)freelist);
+
+ heap_page_freelist_append(page, freelist);
+
+ cache->using_page = NULL;
+ cache->freelist = NULL;
+ }
+}
+
+static void
+gc_sweep_start(rb_objspace_t *objspace)
+{
+ gc_mode_transition(objspace, gc_mode_sweeping);
+ objspace->rincgc.pooled_slots = 0;
+
+#if GC_CAN_COMPILE_COMPACTION
+ if (objspace->flags.during_compacting) {
+ gc_sort_heap_by_compare_func(
+ objspace,
+ objspace->rcompactor.compare_func ? objspace->rcompactor.compare_func : compare_pinned_slots
+ );
+ }
+#endif
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ gc_sweep_start_heap(objspace, heap);
+
+ /* We should call gc_sweep_finish_heap for size pools with no pages. */
+ if (heap->sweeping_page == NULL) {
+ GC_ASSERT(heap->total_pages == 0);
+ GC_ASSERT(heap->total_slots == 0);
+ gc_sweep_finish_heap(objspace, heap);
+ }
+ }
+
+ rb_gc_ractor_newobj_cache_foreach(gc_ractor_newobj_cache_clear, NULL);
+}
+
+static void
+gc_sweep_finish_heap(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ size_t total_slots = heap->total_slots;
+ size_t swept_slots = heap->freed_slots + heap->empty_slots;
+
+ size_t init_slots = gc_params.heap_init_bytes / heap->slot_size;
+ size_t min_free_slots = (size_t)(MAX(total_slots, init_slots) * gc_params.heap_free_slots_min_ratio);
+
+ if (swept_slots < min_free_slots &&
+ /* The heap is a growth heap if it freed more slots than had empty slots. */
+ ((heap->empty_slots == 0 && total_slots > 0) || heap->freed_slots > heap->empty_slots)) {
+ /* If we don't have enough slots and we have pages on the tomb heap, move
+ * pages from the tomb heap to the eden heap. This may prevent page
+ * creation thrashing (frequently allocating and deallocting pages) and
+ * GC thrashing (running GC more frequently than required). */
+ struct heap_page *resurrected_page;
+ while (swept_slots < min_free_slots &&
+ (resurrected_page = heap_page_resurrect(objspace))) {
+ heap_add_page(objspace, heap, resurrected_page);
+ heap_add_freepage(heap, resurrected_page);
+
+ swept_slots += resurrected_page->free_slots;
+ }
+
+ if (swept_slots < min_free_slots) {
+ /* Grow this heap if we are in a major GC or if we haven't run at least
+ * RVALUE_OLD_AGE minor GC since the last major GC. */
+ if (is_full_marking(objspace) ||
+ objspace->profile.count - objspace->rgengc.last_major_gc < RVALUE_OLD_AGE) {
+ if (objspace->heap_pages.allocatable_bytes < min_free_slots * heap->slot_size) {
+ heap_allocatable_bytes_expand(objspace, heap, swept_slots, heap->total_slots, heap->slot_size);
+ }
+ }
+ else if (swept_slots < min_free_slots * 7 / 8 &&
+ objspace->heap_pages.allocatable_bytes < (min_free_slots * 7 / 8 - swept_slots) * heap->slot_size) {
+ gc_needs_major_flags |= GPR_FLAG_MAJOR_BY_NOFREE;
+ heap->force_major_gc_count++;
+ }
+ }
+ }
+}
+
+static void
+gc_sweep_finish(rb_objspace_t *objspace)
+{
+ gc_report(1, objspace, "gc_sweep_finish\n");
+
+ gc_prof_set_heap_info(objspace);
+ heap_pages_free_unused_pages(objspace);
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+
+ heap->freed_slots = 0;
+ heap->empty_slots = 0;
+
+ if (!will_be_incremental_marking(objspace)) {
+ struct heap_page *end_page = heap->free_pages;
+ if (end_page) {
+ while (end_page->free_next) end_page = end_page->free_next;
+ end_page->free_next = heap->pooled_pages;
+ }
+ else {
+ heap->free_pages = heap->pooled_pages;
+ }
+ heap->pooled_pages = NULL;
+ objspace->rincgc.pooled_slots = 0;
+ }
+ }
+
+ (void)gc_malloc_counters_snapshot(objspace, &objspace->malloc_counters.counters);
+#if RGENGC_ESTIMATE_OLDMALLOC
+ if (objspace->profile.latest_gc_info & GPR_FLAG_MAJOR_MASK) {
+ (void)gc_malloc_counters_snapshot(objspace, &objspace->malloc_counters.oldcounters);
+ }
+#endif
+
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_END_SWEEP);
+ gc_mode_transition(objspace, gc_mode_none);
+
+#if RGENGC_CHECK_MODE >= 2
+ gc_verify_internal_consistency(objspace);
+#endif
+}
+
+static int
+gc_sweep_step(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ struct heap_page *sweep_page = heap->sweeping_page;
+ int swept_slots = 0;
+ int pooled_slots = 0;
+ int sweep_budget = GC_INCREMENTAL_SWEEP_BYTES / heap->slot_size;
+ int pool_budget = GC_INCREMENTAL_SWEEP_POOL_BYTES / heap->slot_size;
+
+ if (sweep_page == NULL) return FALSE;
+
+#if GC_ENABLE_LAZY_SWEEP
+ gc_prof_sweep_timer_start(objspace);
+#endif
+
+ do {
+ RUBY_DEBUG_LOG("sweep_page:%p", (void *)sweep_page);
+
+ struct gc_sweep_context ctx = {
+ .page = sweep_page,
+ .final_slots = 0,
+ .freed_slots = 0,
+ .empty_slots = 0,
+ };
+ gc_sweep_page(objspace, heap, &ctx);
+ int free_slots = ctx.freed_slots + ctx.empty_slots;
+
+ heap->sweeping_page = ccan_list_next(&heap->pages, sweep_page, page_node);
+
+ if (free_slots == sweep_page->total_slots) {
+ /* There are no living objects, so move this page to the global empty pages. */
+ heap_unlink_page(objspace, heap, sweep_page);
+
+ sweep_page->start = 0;
+ sweep_page->total_slots = 0;
+ sweep_page->slot_size = 0;
+ sweep_page->heap = NULL;
+ sweep_page->free_slots = 0;
+
+ asan_unlock_freelist(sweep_page);
+ sweep_page->freelist = NULL;
+ asan_lock_freelist(sweep_page);
+
+ asan_poison_memory_region(sweep_page->body, HEAP_PAGE_SIZE);
+
+ objspace->empty_pages_count++;
+ sweep_page->free_next = objspace->empty_pages;
+ objspace->empty_pages = sweep_page;
+ }
+ else if (free_slots > 0) {
+ heap->freed_slots += ctx.freed_slots;
+ heap->empty_slots += ctx.empty_slots;
+
+ if (pooled_slots < pool_budget) {
+ heap_add_poolpage(objspace, heap, sweep_page);
+ pooled_slots += free_slots;
+ }
+ else {
+ heap_add_freepage(heap, sweep_page);
+ swept_slots += free_slots;
+ if (swept_slots > sweep_budget) {
+ break;
+ }
+ }
+ }
+ else {
+ sweep_page->free_next = NULL;
+ }
+ } while ((sweep_page = heap->sweeping_page));
+
+ if (!heap->sweeping_page) {
+ objspace->sweeping_heap_count--;
+ GC_ASSERT(objspace->sweeping_heap_count >= 0);
+ gc_sweep_finish_heap(objspace, heap);
+
+ if (!has_sweeping_pages(objspace)) {
+ gc_sweep_finish(objspace);
+ }
+ }
+
+#if GC_ENABLE_LAZY_SWEEP
+ gc_prof_sweep_timer_stop(objspace);
+#endif
+
+ return heap->free_pages != NULL;
+}
+
+static void
+gc_sweep_rest(rb_objspace_t *objspace)
+{
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+
+ while (heap->sweeping_page) {
+ gc_sweep_step(objspace, heap);
+ }
+ }
+}
+
+static void
+gc_sweep_continue(rb_objspace_t *objspace, rb_heap_t *sweep_heap)
+{
+ GC_ASSERT(dont_gc_val() == FALSE || objspace->profile.latest_gc_info & GPR_FLAG_METHOD);
+ if (!GC_ENABLE_LAZY_SWEEP) return;
+
+ gc_sweeping_enter(objspace);
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ if (gc_sweep_step(objspace, heap)) {
+ GC_ASSERT(heap->free_pages != NULL);
+ }
+ else if (heap == sweep_heap) {
+ if (objspace->empty_pages_count > 0 || objspace->heap_pages.allocatable_bytes > 0) {
+ /* [Bug #21548]
+ *
+ * If this heap is the heap we want to sweep, but we weren't able
+ * to free any slots, but we also either have empty pages or could
+ * allocate new pages, then we want to preemptively claim a page
+ * because it's possible that sweeping another heap will call
+ * gc_sweep_finish_heap, which may use up all of the
+ * empty/allocatable pages. If other heaps are not finished sweeping
+ * then we do not finish this GC and we will end up triggering a new
+ * GC cycle during this GC phase. */
+ heap_page_allocate_and_initialize(objspace, heap);
+
+ GC_ASSERT(heap->free_pages != NULL);
+ }
+ else {
+ /* Not allowed to create a new page so finish sweeping. */
+ gc_sweep_rest(objspace);
+ GC_ASSERT(gc_mode(objspace) == gc_mode_none);
+ break;
+ }
+ }
+ }
+
+ gc_sweeping_exit(objspace);
+}
+
+VALUE
+rb_gc_impl_location(void *objspace_ptr, VALUE value)
+{
+ VALUE destination;
+
+ asan_unpoisoning_object(value) {
+ if (BUILTIN_TYPE(value) == T_MOVED) {
+ destination = (VALUE)RMOVED(value)->destination;
+ GC_ASSERT(BUILTIN_TYPE(destination) != T_NONE);
+ }
+ else {
+ destination = value;
+ }
+ }
+
+ return destination;
+}
+
+#if GC_CAN_COMPILE_COMPACTION
+static void
+invalidate_moved_plane(rb_objspace_t *objspace, struct heap_page *page, uintptr_t p, bits_t bitset)
+{
+ if (bitset) {
+ do {
+ if (bitset & 1) {
+ VALUE forwarding_object = (VALUE)p;
+ VALUE object;
+
+ if (BUILTIN_TYPE(forwarding_object) == T_MOVED) {
+ GC_ASSERT(RVALUE_PINNED(objspace, forwarding_object));
+ GC_ASSERT(!RVALUE_MARKED(objspace, forwarding_object));
+
+ CLEAR_IN_BITMAP(GET_HEAP_PINNED_BITS(forwarding_object), forwarding_object);
+
+ object = rb_gc_impl_location(objspace, forwarding_object);
+ gc_move(objspace, object, forwarding_object, GET_HEAP_PAGE(object), page);
+ /* forwarding_object is now our actual object, and "object"
+ * is the free slot for the original page */
+
+ struct heap_page *orig_page = GET_HEAP_PAGE(object);
+ orig_page->free_slots++;
+ RVALUE_AGE_SET_BITMAP(object, 0);
+ heap_page_add_freeobj(objspace, orig_page, object);
+
+ GC_ASSERT(RVALUE_MARKED(objspace, forwarding_object));
+ GC_ASSERT(BUILTIN_TYPE(forwarding_object) != T_MOVED);
+ GC_ASSERT(BUILTIN_TYPE(forwarding_object) != T_NONE);
+ }
+ }
+ p += page->slot_size;
+ bitset >>= 1;
+ } while (bitset);
+ }
+}
+
+static void
+invalidate_moved_page(rb_objspace_t *objspace, struct heap_page *page)
+{
+ int i;
+ bits_t *mark_bits, *pin_bits;
+ bits_t bitset;
+ short slot_size = page->slot_size;
+ int total_slots = page->total_slots;
+ int bitmap_plane_count = CEILDIV(total_slots, BITS_BITLENGTH);
+
+ mark_bits = page->mark_bits;
+ pin_bits = page->pinned_bits;
+
+ uintptr_t p = page->start;
+
+ for (i=0; i < bitmap_plane_count; i++) {
+ /* Moved objects are pinned but never marked. We reuse the pin bits
+ * to indicate there is a moved object in this slot. */
+ bitset = pin_bits[i] & ~mark_bits[i];
+ invalidate_moved_plane(objspace, page, p, bitset);
+ p += BITS_BITLENGTH * slot_size;
+ }
+}
+#endif
+
+static void
+gc_compact_start(rb_objspace_t *objspace)
+{
+ struct heap_page *page = NULL;
+ gc_mode_transition(objspace, gc_mode_compacting);
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ page->flags.before_sweep = TRUE;
+ }
+
+ heap->compact_cursor = ccan_list_tail(&heap->pages, struct heap_page, page_node);
+ heap->compact_cursor_index = 0;
+ }
+
+ if (gc_prof_enabled(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+ record->moved_objects = objspace->rcompactor.total_moved;
+ }
+
+ memset(objspace->rcompactor.considered_count_table, 0, T_MASK * sizeof(size_t));
+ memset(objspace->rcompactor.moved_count_table, 0, T_MASK * sizeof(size_t));
+ memset(objspace->rcompactor.moved_up_count_table, 0, T_MASK * sizeof(size_t));
+ memset(objspace->rcompactor.moved_down_count_table, 0, T_MASK * sizeof(size_t));
+
+ /* Set up read barrier for pages containing MOVED objects */
+ install_handlers();
+}
+
+static void gc_sweep_compact(rb_objspace_t *objspace);
+
+static void
+gc_sweep(rb_objspace_t *objspace)
+{
+ gc_sweeping_enter(objspace);
+
+ const unsigned int immediate_sweep = objspace->flags.immediate_sweep;
+
+ gc_report(1, objspace, "gc_sweep: immediate: %d\n", immediate_sweep);
+
+ gc_sweep_start(objspace);
+ if (objspace->flags.during_compacting) {
+ gc_sweep_compact(objspace);
+ }
+
+ if (immediate_sweep) {
+#if !GC_ENABLE_LAZY_SWEEP
+ gc_prof_sweep_timer_start(objspace);
+#endif
+ gc_sweep_rest(objspace);
+#if !GC_ENABLE_LAZY_SWEEP
+ gc_prof_sweep_timer_stop(objspace);
+#endif
+ }
+ else {
+
+ /* Sweep every size pool. */
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ gc_sweep_step(objspace, heap);
+ }
+ }
+
+ gc_sweeping_exit(objspace);
+}
+
+/* Marking - Marking stack */
+
+static stack_chunk_t *
+stack_chunk_alloc(void)
+{
+ stack_chunk_t *res;
+
+ res = malloc(sizeof(stack_chunk_t));
+ if (!res)
+ rb_memerror();
+
+ return res;
+}
+
+static inline int
+is_mark_stack_empty(mark_stack_t *stack)
+{
+ return stack->chunk == NULL;
+}
+
+static size_t
+mark_stack_size(mark_stack_t *stack)
+{
+ size_t size = stack->index;
+ stack_chunk_t *chunk = stack->chunk ? stack->chunk->next : NULL;
+
+ while (chunk) {
+ size += stack->limit;
+ chunk = chunk->next;
+ }
+ return size;
+}
+
+static void
+add_stack_chunk_cache(mark_stack_t *stack, stack_chunk_t *chunk)
+{
+ chunk->next = stack->cache;
+ stack->cache = chunk;
+ stack->cache_size++;
+}
+
+static void
+shrink_stack_chunk_cache(mark_stack_t *stack)
+{
+ stack_chunk_t *chunk;
+
+ if (stack->unused_cache_size > (stack->cache_size/2)) {
+ chunk = stack->cache;
+ stack->cache = stack->cache->next;
+ stack->cache_size--;
+ free(chunk);
+ }
+ stack->unused_cache_size = stack->cache_size;
+}
+
+static void
+push_mark_stack_chunk(mark_stack_t *stack)
+{
+ stack_chunk_t *next;
+
+ GC_ASSERT(stack->index == stack->limit);
+
+ if (stack->cache_size > 0) {
+ next = stack->cache;
+ stack->cache = stack->cache->next;
+ stack->cache_size--;
+ if (stack->unused_cache_size > stack->cache_size)
+ stack->unused_cache_size = stack->cache_size;
+ }
+ else {
+ next = stack_chunk_alloc();
+ }
+ next->next = stack->chunk;
+ stack->chunk = next;
+ stack->index = 0;
+}
+
+static void
+pop_mark_stack_chunk(mark_stack_t *stack)
+{
+ stack_chunk_t *prev;
+
+ prev = stack->chunk->next;
+ GC_ASSERT(stack->index == 0);
+ add_stack_chunk_cache(stack, stack->chunk);
+ stack->chunk = prev;
+ stack->index = stack->limit;
+}
+
+static void
+mark_stack_chunk_list_free(stack_chunk_t *chunk)
+{
+ stack_chunk_t *next = NULL;
+
+ while (chunk != NULL) {
+ next = chunk->next;
+ free(chunk);
+ chunk = next;
+ }
+}
+
+static void
+free_stack_chunks(mark_stack_t *stack)
+{
+ mark_stack_chunk_list_free(stack->chunk);
+}
+
+static void
+mark_stack_free_cache(mark_stack_t *stack)
+{
+ mark_stack_chunk_list_free(stack->cache);
+ stack->cache_size = 0;
+ stack->unused_cache_size = 0;
+}
+
+static void
+push_mark_stack(mark_stack_t *stack, VALUE obj)
+{
+ switch (BUILTIN_TYPE(obj)) {
+ case T_OBJECT:
+ case T_CLASS:
+ case T_MODULE:
+ case T_FLOAT:
+ case T_STRING:
+ case T_REGEXP:
+ case T_ARRAY:
+ case T_HASH:
+ case T_STRUCT:
+ case T_BIGNUM:
+ case T_FILE:
+ case T_DATA:
+ case T_MATCH:
+ case T_COMPLEX:
+ case T_RATIONAL:
+ case T_TRUE:
+ case T_FALSE:
+ case T_SYMBOL:
+ case T_IMEMO:
+ case T_ICLASS:
+ if (stack->index == stack->limit) {
+ push_mark_stack_chunk(stack);
+ }
+ stack->chunk->data[stack->index++] = obj;
+ return;
+
+ case T_NONE:
+ case T_NIL:
+ case T_FIXNUM:
+ case T_MOVED:
+ case T_ZOMBIE:
+ case T_UNDEF:
+ case T_MASK:
+ rb_bug("push_mark_stack() called for broken object");
+ break;
+
+ case T_NODE:
+ rb_bug("push_mark_stack: unexpected T_NODE object");
+ break;
+ }
+
+ rb_bug("rb_gc_mark(): unknown data type 0x%x(%p) %s",
+ BUILTIN_TYPE(obj), (void *)obj,
+ is_pointer_to_heap((rb_objspace_t *)rb_gc_get_objspace(), (void *)obj) ? "corrupted object" : "non object");
+}
+
+static int
+pop_mark_stack(mark_stack_t *stack, VALUE *data)
+{
+ if (is_mark_stack_empty(stack)) {
+ return FALSE;
+ }
+ if (stack->index == 1) {
+ *data = stack->chunk->data[--stack->index];
+ pop_mark_stack_chunk(stack);
+ }
+ else {
+ *data = stack->chunk->data[--stack->index];
+ }
+ return TRUE;
+}
+
+static void
+init_mark_stack(mark_stack_t *stack)
+{
+ int i;
+
+ MEMZERO(stack, mark_stack_t, 1);
+ stack->index = stack->limit = STACK_CHUNK_SIZE;
+
+ for (i=0; i < 4; i++) {
+ add_stack_chunk_cache(stack, stack_chunk_alloc());
+ }
+ stack->unused_cache_size = stack->cache_size;
+}
+
+/* Marking */
+
+static void
+rgengc_check_relation(rb_objspace_t *objspace, VALUE obj)
+{
+ if (objspace->rgengc.parent_object_old_p) {
+ if (RVALUE_WB_UNPROTECTED(objspace, obj) || !RVALUE_OLD_P(objspace, obj)) {
+ rgengc_remember(objspace, objspace->rgengc.parent_object);
+ }
+ }
+}
+
+static inline int
+gc_mark_set(rb_objspace_t *objspace, VALUE obj)
+{
+ if (RVALUE_MARKED(objspace, obj)) return 0;
+ MARK_IN_BITMAP(GET_HEAP_MARK_BITS(obj), obj);
+ return 1;
+}
+
+static void
+gc_aging(rb_objspace_t *objspace, VALUE obj)
+{
+ /* Disable aging if Major GC's are disabled. This will prevent longish lived
+ * objects filling up the heap at the expense of marking many more objects.
+ *
+ * We should always pre-warm our process when disabling majors, by running
+ * GC manually several times so that most objects likely to become oldgen
+ * are already oldgen.
+ */
+ if(!gc_config_full_mark_val)
+ return;
+
+ struct heap_page *page = GET_HEAP_PAGE(obj);
+
+ GC_ASSERT(RVALUE_MARKING(objspace, obj) == FALSE);
+ check_rvalue_consistency(objspace, obj);
+
+ if (!RVALUE_PAGE_WB_UNPROTECTED(page, obj)) {
+ if (!RVALUE_OLD_P(objspace, obj)) {
+ int t = BUILTIN_TYPE(obj);
+ if (t == T_CLASS || t == T_MODULE || t == T_ICLASS) {
+ gc_report(3, objspace, "gc_aging: YOUNG class: %s\n", rb_obj_info(obj));
+ RVALUE_AGE_SET(obj, RVALUE_OLD_AGE);
+ RVALUE_OLD_UNCOLLECTIBLE_SET(objspace, obj);
+ }
+ else {
+ gc_report(3, objspace, "gc_aging: YOUNG: %s\n", rb_obj_info(obj));
+ RVALUE_AGE_INC(objspace, obj);
+ }
+ }
+ else if (is_full_marking(objspace)) {
+ GC_ASSERT(RVALUE_PAGE_UNCOLLECTIBLE(page, obj) == FALSE);
+ RVALUE_PAGE_OLD_UNCOLLECTIBLE_SET(objspace, page, obj);
+ }
+ }
+ check_rvalue_consistency(objspace, obj);
+
+ objspace->marked_slots++;
+}
+
+static void
+gc_grey(rb_objspace_t *objspace, VALUE obj)
+{
+#if RGENGC_CHECK_MODE
+ if (RVALUE_MARKED(objspace, obj) == FALSE) rb_bug("gc_grey: %s is not marked.", rb_obj_info(obj));
+ if (RVALUE_MARKING(objspace, obj) == TRUE) rb_bug("gc_grey: %s is marking/remembered.", rb_obj_info(obj));
+#endif
+
+ if (is_incremental_marking(objspace)) {
+ MARK_IN_BITMAP(GET_HEAP_MARKING_BITS(obj), obj);
+ }
+
+ if (RB_FL_TEST_RAW(obj, RUBY_FL_WEAK_REFERENCE)) {
+ rb_darray_append_without_gc(&objspace->weak_references, obj);
+ }
+
+ push_mark_stack(&objspace->mark_stack, obj);
+}
+
+static inline void
+gc_mark_check_t_none(rb_objspace_t *objspace, VALUE obj)
+{
+ if (RB_UNLIKELY(BUILTIN_TYPE(obj) == T_NONE)) {
+ enum {info_size = 256};
+ char obj_info_buf[info_size];
+ rb_raw_obj_info(obj_info_buf, info_size, obj);
+
+ char parent_obj_info_buf[info_size];
+ rb_raw_obj_info(parent_obj_info_buf, info_size, objspace->rgengc.parent_object);
+
+ rb_bug("try to mark T_NONE object (obj: %s, parent: %s)", obj_info_buf, parent_obj_info_buf);
+ }
+}
+
+static void
+gc_mark(rb_objspace_t *objspace, VALUE obj)
+{
+ GC_ASSERT(during_gc);
+ GC_ASSERT(!objspace->flags.during_reference_updating);
+
+ rgengc_check_relation(objspace, obj);
+ if (!gc_mark_set(objspace, obj)) return; /* already marked */
+
+ if (0) { // for debug GC marking miss
+ RUBY_DEBUG_LOG("%p (%s) parent:%p (%s)",
+ (void *)obj, obj_type_name(obj),
+ (void *)objspace->rgengc.parent_object, obj_type_name(objspace->rgengc.parent_object));
+ }
+
+ gc_mark_check_t_none(objspace, obj);
+
+ gc_aging(objspace, obj);
+ gc_grey(objspace, obj);
+}
+
+static inline void
+gc_pin(rb_objspace_t *objspace, VALUE obj)
+{
+ GC_ASSERT(!SPECIAL_CONST_P(obj));
+ if (RB_UNLIKELY(objspace->flags.during_compacting)) {
+ if (RB_LIKELY(during_gc)) {
+ if (!RVALUE_PINNED(objspace, obj)) {
+ GC_ASSERT(GET_HEAP_PAGE(obj)->pinned_slots <= GET_HEAP_PAGE(obj)->total_slots);
+ GET_HEAP_PAGE(obj)->pinned_slots++;
+ MARK_IN_BITMAP(GET_HEAP_PINNED_BITS(obj), obj);
+ }
+ }
+ }
+}
+
+static inline void
+gc_mark_and_pin(rb_objspace_t *objspace, VALUE obj)
+{
+ gc_pin(objspace, obj);
+ gc_mark(objspace, obj);
+}
+
+void
+rb_gc_impl_mark_and_move(void *objspace_ptr, VALUE *ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (RB_UNLIKELY(objspace->flags.during_reference_updating)) {
+ GC_ASSERT(objspace->flags.during_compacting);
+ GC_ASSERT(during_gc);
+
+ VALUE destination = rb_gc_impl_location(objspace, *ptr);
+ if (destination != *ptr) {
+ *ptr = destination;
+ }
+ }
+ else {
+ gc_mark(objspace, *ptr);
+ }
+}
+
+void
+rb_gc_impl_mark(void *objspace_ptr, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ gc_mark(objspace, obj);
+}
+
+void
+rb_gc_impl_mark_and_pin(void *objspace_ptr, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ gc_mark_and_pin(objspace, obj);
+}
+
+void
+rb_gc_impl_mark_maybe(void *objspace_ptr, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ (void)VALGRIND_MAKE_MEM_DEFINED(&obj, sizeof(obj));
+
+ if (is_pointer_to_heap(objspace, (void *)obj)) {
+ asan_unpoisoning_object(obj) {
+ /* Garbage can live on the stack, so do not mark or pin */
+ switch (BUILTIN_TYPE(obj)) {
+ case T_ZOMBIE:
+ case T_NONE:
+ break;
+ default:
+ gc_mark_and_pin(objspace, obj);
+ break;
+ }
+ }
+ }
+}
+
+static int
+pin_value(st_data_t key, st_data_t value, st_data_t data)
+{
+ rb_gc_impl_mark_and_pin((void *)data, (VALUE)value);
+
+ return ST_CONTINUE;
+}
+
+static inline void
+gc_mark_set_parent_raw(rb_objspace_t *objspace, VALUE obj, bool old_p)
+{
+ asan_unpoison_memory_region(&objspace->rgengc.parent_object, sizeof(objspace->rgengc.parent_object), false);
+ asan_unpoison_memory_region(&objspace->rgengc.parent_object_old_p, sizeof(objspace->rgengc.parent_object_old_p), false);
+ objspace->rgengc.parent_object = obj;
+ objspace->rgengc.parent_object_old_p = old_p;
+}
+
+static inline void
+gc_mark_set_parent(rb_objspace_t *objspace, VALUE obj)
+{
+ gc_mark_set_parent_raw(objspace, obj, RVALUE_OLD_P(objspace, obj));
+}
+
+static inline void
+gc_mark_set_parent_invalid(rb_objspace_t *objspace)
+{
+ asan_poison_memory_region(&objspace->rgengc.parent_object, sizeof(objspace->rgengc.parent_object));
+ asan_poison_memory_region(&objspace->rgengc.parent_object_old_p, sizeof(objspace->rgengc.parent_object_old_p));
+}
+
+static void
+mark_roots(rb_objspace_t *objspace, const char **categoryp)
+{
+#define MARK_CHECKPOINT(category) do { \
+ if (categoryp) *categoryp = category; \
+} while (0)
+
+ MARK_CHECKPOINT("objspace");
+ gc_mark_set_parent_raw(objspace, Qundef, false);
+
+ if (finalizer_table != NULL) {
+ st_foreach(finalizer_table, pin_value, (st_data_t)objspace);
+ }
+
+ if (stress_to_class) rb_gc_mark(stress_to_class);
+
+ rb_gc_save_machine_context();
+ rb_gc_mark_roots(objspace, categoryp);
+ gc_mark_set_parent_invalid(objspace);
+}
+
+static void
+gc_mark_children(rb_objspace_t *objspace, VALUE obj)
+{
+ gc_mark_set_parent(objspace, obj);
+ rb_gc_mark_children(objspace, obj);
+ gc_mark_set_parent_invalid(objspace);
+}
+
+/**
+ * incremental: 0 -> not incremental (do all)
+ * incremental: n -> mark at most `n' objects
+ */
+static inline int
+gc_mark_stacked_objects(rb_objspace_t *objspace, int incremental, size_t count)
+{
+ mark_stack_t *mstack = &objspace->mark_stack;
+ VALUE obj;
+ size_t marked_slots_at_the_beginning = objspace->marked_slots;
+ size_t popped_count = 0;
+
+ while (pop_mark_stack(mstack, &obj)) {
+ if (obj == Qundef) continue; /* skip */
+
+ if (RGENGC_CHECK_MODE && !RVALUE_MARKED(objspace, obj)) {
+ rb_bug("gc_mark_stacked_objects: %s is not marked.", rb_obj_info(obj));
+ }
+ gc_mark_children(objspace, obj);
+
+ if (incremental) {
+ if (RGENGC_CHECK_MODE && !RVALUE_MARKING(objspace, obj)) {
+ rb_bug("gc_mark_stacked_objects: incremental, but marking bit is 0");
+ }
+ CLEAR_IN_BITMAP(GET_HEAP_MARKING_BITS(obj), obj);
+ popped_count++;
+
+ if (popped_count + (objspace->marked_slots - marked_slots_at_the_beginning) > count) {
+ break;
+ }
+ }
+ else {
+ /* just ignore marking bits */
+ }
+ }
+
+ if (RGENGC_CHECK_MODE >= 3) gc_verify_internal_consistency(objspace);
+
+ if (is_mark_stack_empty(mstack)) {
+ shrink_stack_chunk_cache(mstack);
+ return TRUE;
+ }
+ else {
+ return FALSE;
+ }
+}
+
+static int
+gc_mark_stacked_objects_incremental(rb_objspace_t *objspace, size_t count)
+{
+ return gc_mark_stacked_objects(objspace, TRUE, count);
+}
+
+static int
+gc_mark_stacked_objects_all(rb_objspace_t *objspace)
+{
+ return gc_mark_stacked_objects(objspace, FALSE, 0);
+}
+
+#if RGENGC_CHECK_MODE >= 4
+
+#define MAKE_ROOTSIG(obj) (((VALUE)(obj) << 1) | 0x01)
+#define IS_ROOTSIG(obj) ((VALUE)(obj) & 0x01)
+#define GET_ROOTSIG(obj) ((const char *)((VALUE)(obj) >> 1))
+
+struct reflist {
+ VALUE *list;
+ int pos;
+ int size;
+};
+
+static struct reflist *
+reflist_create(VALUE obj)
+{
+ struct reflist *refs = xmalloc(sizeof(struct reflist));
+ refs->size = 1;
+ refs->list = ALLOC_N(VALUE, refs->size);
+ refs->list[0] = obj;
+ refs->pos = 1;
+ return refs;
+}
+
+static void
+reflist_destruct(struct reflist *refs)
+{
+ xfree(refs->list);
+ xfree(refs);
+}
+
+static void
+reflist_add(struct reflist *refs, VALUE obj)
+{
+ if (refs->pos == refs->size) {
+ refs->size *= 2;
+ SIZED_REALLOC_N(refs->list, VALUE, refs->size, refs->size/2);
+ }
+
+ refs->list[refs->pos++] = obj;
+}
+
+static void
+reflist_dump(struct reflist *refs)
+{
+ int i;
+ for (i=0; i<refs->pos; i++) {
+ VALUE obj = refs->list[i];
+ if (IS_ROOTSIG(obj)) { /* root */
+ fprintf(stderr, "<root@%s>", GET_ROOTSIG(obj));
+ }
+ else {
+ fprintf(stderr, "<%s>", rb_obj_info(obj));
+ }
+ if (i+1 < refs->pos) fprintf(stderr, ", ");
+ }
+}
+
+static int
+reflist_referred_from_machine_context(struct reflist *refs)
+{
+ int i;
+ for (i=0; i<refs->pos; i++) {
+ VALUE obj = refs->list[i];
+ if (IS_ROOTSIG(obj) && strcmp(GET_ROOTSIG(obj), "machine_context") == 0) return 1;
+ }
+ return 0;
+}
+
+struct allrefs {
+ rb_objspace_t *objspace;
+ /* a -> obj1
+ * b -> obj1
+ * c -> obj1
+ * c -> obj2
+ * d -> obj3
+ * #=> {obj1 => [a, b, c], obj2 => [c, d]}
+ */
+ struct st_table *references;
+ const char *category;
+ VALUE root_obj;
+ mark_stack_t mark_stack;
+};
+
+static int
+allrefs_add(struct allrefs *data, VALUE obj)
+{
+ struct reflist *refs;
+ st_data_t r;
+
+ if (st_lookup(data->references, obj, &r)) {
+ refs = (struct reflist *)r;
+ reflist_add(refs, data->root_obj);
+ return 0;
+ }
+ else {
+ refs = reflist_create(data->root_obj);
+ st_insert(data->references, obj, (st_data_t)refs);
+ return 1;
+ }
+}
+
+static void
+allrefs_i(VALUE obj, void *ptr)
+{
+ struct allrefs *data = (struct allrefs *)ptr;
+
+ if (allrefs_add(data, obj)) {
+ push_mark_stack(&data->mark_stack, obj);
+ }
+}
+
+static void
+allrefs_roots_i(VALUE obj, void *ptr)
+{
+ struct allrefs *data = (struct allrefs *)ptr;
+ if (strlen(data->category) == 0) rb_bug("!!!");
+ data->root_obj = MAKE_ROOTSIG(data->category);
+
+ if (allrefs_add(data, obj)) {
+ push_mark_stack(&data->mark_stack, obj);
+ }
+}
+#define PUSH_MARK_FUNC_DATA(v) do { \
+ struct gc_mark_func_data_struct *prev_mark_func_data = GET_VM()->gc.mark_func_data; \
+ GET_VM()->gc.mark_func_data = (v);
+
+#define POP_MARK_FUNC_DATA() GET_VM()->gc.mark_func_data = prev_mark_func_data;} while (0)
+
+static st_table *
+objspace_allrefs(rb_objspace_t *objspace)
+{
+ struct allrefs data;
+ struct gc_mark_func_data_struct mfd;
+ VALUE obj;
+ int prev_dont_gc = dont_gc_val();
+ dont_gc_on();
+
+ data.objspace = objspace;
+ data.references = st_init_numtable();
+ init_mark_stack(&data.mark_stack);
+
+ mfd.mark_func = allrefs_roots_i;
+ mfd.data = &data;
+
+ /* traverse root objects */
+ PUSH_MARK_FUNC_DATA(&mfd);
+ GET_VM()->gc.mark_func_data = &mfd;
+ mark_roots(objspace, &data.category);
+ POP_MARK_FUNC_DATA();
+
+ /* traverse rest objects reachable from root objects */
+ while (pop_mark_stack(&data.mark_stack, &obj)) {
+ rb_objspace_reachable_objects_from(data.root_obj = obj, allrefs_i, &data);
+ }
+ free_stack_chunks(&data.mark_stack);
+
+ dont_gc_set(prev_dont_gc);
+ return data.references;
+}
+
+static int
+objspace_allrefs_destruct_i(st_data_t key, st_data_t value, st_data_t ptr)
+{
+ struct reflist *refs = (struct reflist *)value;
+ reflist_destruct(refs);
+ return ST_CONTINUE;
+}
+
+static void
+objspace_allrefs_destruct(struct st_table *refs)
+{
+ st_foreach(refs, objspace_allrefs_destruct_i, 0);
+ st_free_table(refs);
+}
+
+#if RGENGC_CHECK_MODE >= 5
+static int
+allrefs_dump_i(st_data_t k, st_data_t v, st_data_t ptr)
+{
+ VALUE obj = (VALUE)k;
+ struct reflist *refs = (struct reflist *)v;
+ fprintf(stderr, "[allrefs_dump_i] %s <- ", rb_obj_info(obj));
+ reflist_dump(refs);
+ fprintf(stderr, "\n");
+ return ST_CONTINUE;
+}
+
+static void
+allrefs_dump(rb_objspace_t *objspace)
+{
+ VALUE size = objspace->rgengc.allrefs_table->num_entries;
+ fprintf(stderr, "[all refs] (size: %"PRIuVALUE")\n", size);
+ st_foreach(objspace->rgengc.allrefs_table, allrefs_dump_i, 0);
+}
+#endif
+
+static int
+gc_check_after_marks_i(st_data_t k, st_data_t v, st_data_t ptr)
+{
+ VALUE obj = k;
+ struct reflist *refs = (struct reflist *)v;
+ rb_objspace_t *objspace = (rb_objspace_t *)ptr;
+
+ /* object should be marked or oldgen */
+ if (!RVALUE_MARKED(objspace, obj)) {
+ fprintf(stderr, "gc_check_after_marks_i: %s is not marked and not oldgen.\n", rb_obj_info(obj));
+ fprintf(stderr, "gc_check_after_marks_i: %p is referred from ", (void *)obj);
+ reflist_dump(refs);
+
+ if (reflist_referred_from_machine_context(refs)) {
+ fprintf(stderr, " (marked from machine stack).\n");
+ /* marked from machine context can be false positive */
+ }
+ else {
+ objspace->rgengc.error_count++;
+ fprintf(stderr, "\n");
+ }
+ }
+ return ST_CONTINUE;
+}
+
+static void
+gc_marks_check(rb_objspace_t *objspace, st_foreach_callback_func *checker_func, const char *checker_name)
+{
+ MALLOC_COUNTERS_LOCK(objspace);
+ struct gc_malloc_bytes saved_malloc = {
+ .malloc = gc_counter_load_relaxed(&objspace->malloc_counters.counters.malloc),
+ .free = gc_counter_load_relaxed(&objspace->malloc_counters.counters.free),
+ .malloc_at_last_gc = gc_counter_load_relaxed(&objspace->malloc_counters.counters.malloc_at_last_gc),
+ .free_at_last_gc = gc_counter_load_relaxed(&objspace->malloc_counters.counters.free_at_last_gc),
+ };
+#if RGENGC_ESTIMATE_OLDMALLOC
+ struct gc_malloc_bytes saved_oldmalloc = {
+ .malloc = gc_counter_load_relaxed(&objspace->malloc_counters.oldcounters.malloc),
+ .free = gc_counter_load_relaxed(&objspace->malloc_counters.oldcounters.free),
+ .malloc_at_last_gc = gc_counter_load_relaxed(&objspace->malloc_counters.oldcounters.malloc_at_last_gc),
+ .free_at_last_gc = gc_counter_load_relaxed(&objspace->malloc_counters.oldcounters.free_at_last_gc),
+ };
+#endif
+ MALLOC_COUNTERS_UNLOCK(objspace);
+ VALUE already_disabled = rb_objspace_gc_disable(objspace);
+
+ objspace->rgengc.allrefs_table = objspace_allrefs(objspace);
+
+ if (checker_func) {
+ st_foreach(objspace->rgengc.allrefs_table, checker_func, (st_data_t)objspace);
+ }
+
+ if (objspace->rgengc.error_count > 0) {
+#if RGENGC_CHECK_MODE >= 5
+ allrefs_dump(objspace);
+#endif
+ if (checker_name) rb_bug("%s: GC has problem.", checker_name);
+ }
+
+ objspace_allrefs_destruct(objspace->rgengc.allrefs_table);
+ objspace->rgengc.allrefs_table = 0;
+
+ if (already_disabled == Qfalse) rb_objspace_gc_enable(objspace);
+ MALLOC_COUNTERS_LOCK(objspace);
+ gc_counter_store_release(&objspace->malloc_counters.counters.malloc, saved_malloc.malloc);
+ gc_counter_store_release(&objspace->malloc_counters.counters.free, saved_malloc.free);
+ gc_counter_store_release(&objspace->malloc_counters.counters.malloc_at_last_gc, saved_malloc.malloc_at_last_gc);
+ gc_counter_store_release(&objspace->malloc_counters.counters.free_at_last_gc, saved_malloc.free_at_last_gc);
+#if RGENGC_ESTIMATE_OLDMALLOC
+ gc_counter_store_release(&objspace->malloc_counters.oldcounters.malloc, saved_oldmalloc.malloc);
+ gc_counter_store_release(&objspace->malloc_counters.oldcounters.free, saved_oldmalloc.free);
+ gc_counter_store_release(&objspace->malloc_counters.oldcounters.malloc_at_last_gc, saved_oldmalloc.malloc_at_last_gc);
+ gc_counter_store_release(&objspace->malloc_counters.oldcounters.free_at_last_gc, saved_oldmalloc.free_at_last_gc);
+#endif
+ MALLOC_COUNTERS_UNLOCK(objspace);
+}
+#endif /* RGENGC_CHECK_MODE >= 4 */
+
+struct verify_internal_consistency_struct {
+ rb_objspace_t *objspace;
+ int err_count;
+ size_t live_object_count;
+ size_t zombie_object_count;
+
+ VALUE parent;
+ size_t old_object_count;
+ size_t remembered_shady_count;
+};
+
+static void
+check_generation_i(const VALUE child, void *ptr)
+{
+ struct verify_internal_consistency_struct *data = (struct verify_internal_consistency_struct *)ptr;
+ const VALUE parent = data->parent;
+
+ if (RGENGC_CHECK_MODE) GC_ASSERT(RVALUE_OLD_P(data->objspace, parent));
+
+ if (!RVALUE_OLD_P(data->objspace, child)) {
+ if (!RVALUE_REMEMBERED(data->objspace, parent) &&
+ !RVALUE_REMEMBERED(data->objspace, child) &&
+ !RVALUE_UNCOLLECTIBLE(data->objspace, child)) {
+ fprintf(stderr, "verify_internal_consistency_reachable_i: WB miss (O->Y) %s -> %s\n", rb_obj_info(parent), rb_obj_info(child));
+ data->err_count++;
+ }
+ }
+}
+
+static void
+check_color_i(const VALUE child, void *ptr)
+{
+ struct verify_internal_consistency_struct *data = (struct verify_internal_consistency_struct *)ptr;
+ const VALUE parent = data->parent;
+
+ if (!RVALUE_WB_UNPROTECTED(data->objspace, parent) && RVALUE_WHITE_P(data->objspace, child)) {
+ fprintf(stderr, "verify_internal_consistency_reachable_i: WB miss (B->W) - %s -> %s\n",
+ rb_obj_info(parent), rb_obj_info(child));
+ data->err_count++;
+ }
+}
+
+static void
+check_children_i(const VALUE child, void *ptr)
+{
+ struct verify_internal_consistency_struct *data = (struct verify_internal_consistency_struct *)ptr;
+ if (check_rvalue_consistency_force(data->objspace, child, FALSE) != 0) {
+ fprintf(stderr, "check_children_i: %s has error (referenced from %s)",
+ rb_obj_info(child), rb_obj_info(data->parent));
+
+ data->err_count++;
+ }
+}
+
+static int
+verify_internal_consistency_i(void *page_start, void *page_end, size_t stride,
+ struct verify_internal_consistency_struct *data)
+{
+ VALUE obj;
+ rb_objspace_t *objspace = data->objspace;
+
+ for (obj = (VALUE)page_start; obj != (VALUE)page_end; obj += stride) {
+ asan_unpoisoning_object(obj) {
+ if (!rb_gc_impl_garbage_object_p(objspace, obj)) {
+ /* count objects */
+ data->live_object_count++;
+ data->parent = obj;
+
+ /* Normally, we don't expect T_MOVED objects to be in the heap.
+ * But they can stay alive on the stack, */
+ if (!gc_object_moved_p(objspace, obj)) {
+ /* moved slots don't have children */
+ rb_objspace_reachable_objects_from(obj, check_children_i, (void *)data);
+ }
+
+ /* check health of children */
+ if (RVALUE_OLD_P(objspace, obj)) data->old_object_count++;
+ if (RVALUE_WB_UNPROTECTED(objspace, obj) && RVALUE_UNCOLLECTIBLE(objspace, obj)) data->remembered_shady_count++;
+
+ if (!is_marking(objspace) && RVALUE_OLD_P(objspace, obj)) {
+ /* reachable objects from an oldgen object should be old or (young with remember) */
+ data->parent = obj;
+ rb_objspace_reachable_objects_from(obj, check_generation_i, (void *)data);
+ }
+
+ if (!is_marking(objspace) && rb_gc_obj_shareable_p(obj)) {
+ rb_gc_verify_shareable(obj);
+ }
+
+ if (is_incremental_marking(objspace)) {
+ if (RVALUE_BLACK_P(objspace, obj)) {
+ /* reachable objects from black objects should be black or grey objects */
+ data->parent = obj;
+ rb_objspace_reachable_objects_from(obj, check_color_i, (void *)data);
+ }
+ }
+ }
+ else {
+ if (BUILTIN_TYPE(obj) == T_ZOMBIE) {
+ data->zombie_object_count++;
+
+ if ((RBASIC(obj)->flags & ~ZOMBIE_OBJ_KEPT_FLAGS) != T_ZOMBIE) {
+ fprintf(stderr, "verify_internal_consistency_i: T_ZOMBIE has extra flags set: %s\n",
+ rb_obj_info(obj));
+ data->err_count++;
+ }
+
+ if (!!FL_TEST(obj, FL_FINALIZE) != !!st_is_member(finalizer_table, obj)) {
+ fprintf(stderr, "verify_internal_consistency_i: FL_FINALIZE %s but %s finalizer_table: %s\n",
+ FL_TEST(obj, FL_FINALIZE) ? "set" : "not set", st_is_member(finalizer_table, obj) ? "in" : "not in",
+ rb_obj_info(obj));
+ data->err_count++;
+ }
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int
+gc_verify_heap_page(rb_objspace_t *objspace, struct heap_page *page, VALUE obj)
+{
+ unsigned int has_remembered_shady = FALSE;
+ unsigned int has_remembered_old = FALSE;
+ int remembered_old_objects = 0;
+ int free_objects = 0;
+ int zombie_objects = 0;
+
+ short slot_size = page->slot_size;
+ uintptr_t start = (uintptr_t)page->start;
+ uintptr_t end = start + page->total_slots * slot_size;
+
+ for (uintptr_t ptr = start; ptr < end; ptr += slot_size) {
+ VALUE val = (VALUE)ptr;
+ asan_unpoisoning_object(val) {
+ enum ruby_value_type type = BUILTIN_TYPE(val);
+
+ if (type == T_NONE) free_objects++;
+ if (type == T_ZOMBIE) zombie_objects++;
+ if (RVALUE_PAGE_UNCOLLECTIBLE(page, val) && RVALUE_PAGE_WB_UNPROTECTED(page, val)) {
+ has_remembered_shady = TRUE;
+ }
+ if (RVALUE_PAGE_MARKING(page, val)) {
+ has_remembered_old = TRUE;
+ remembered_old_objects++;
+ }
+ }
+ }
+
+ if (!is_incremental_marking(objspace) &&
+ page->flags.has_remembered_objects == FALSE && has_remembered_old == TRUE) {
+
+ for (uintptr_t ptr = start; ptr < end; ptr += slot_size) {
+ VALUE val = (VALUE)ptr;
+ if (RVALUE_PAGE_MARKING(page, val)) {
+ fprintf(stderr, "marking -> %s\n", rb_obj_info(val));
+ }
+ }
+ rb_bug("page %p's has_remembered_objects should be false, but there are remembered old objects (%d). %s",
+ (void *)page, remembered_old_objects, obj ? rb_obj_info(obj) : "");
+ }
+
+ if (page->flags.has_uncollectible_wb_unprotected_objects == FALSE && has_remembered_shady == TRUE) {
+ rb_bug("page %p's has_remembered_shady should be false, but there are remembered shady objects. %s",
+ (void *)page, obj ? rb_obj_info(obj) : "");
+ }
+
+ if (0) {
+ /* free_slots may not equal to free_objects */
+ if (page->free_slots != free_objects) {
+ rb_bug("page %p's free_slots should be %d, but %d", (void *)page, page->free_slots, free_objects);
+ }
+ }
+ if (page->final_slots != zombie_objects) {
+ rb_bug("page %p's final_slots should be %d, but %d", (void *)page, page->final_slots, zombie_objects);
+ }
+
+ return remembered_old_objects;
+}
+
+static int
+gc_verify_heap_pages_(rb_objspace_t *objspace, struct ccan_list_head *head)
+{
+ int remembered_old_objects = 0;
+ struct heap_page *page = 0;
+
+ ccan_list_for_each(head, page, page_node) {
+ asan_unlock_freelist(page);
+ struct free_slot *p = page->freelist;
+ while (p) {
+ VALUE vp = (VALUE)p;
+ VALUE prev = vp;
+ rb_asan_unpoison_object(vp, false);
+ if (BUILTIN_TYPE(vp) != T_NONE) {
+ fprintf(stderr, "freelist slot expected to be T_NONE but was: %s\n", rb_obj_info(vp));
+ }
+ p = p->next;
+ rb_asan_poison_object(prev);
+ }
+ asan_lock_freelist(page);
+
+ if (page->flags.has_remembered_objects == FALSE) {
+ remembered_old_objects += gc_verify_heap_page(objspace, page, Qfalse);
+ }
+ }
+
+ return remembered_old_objects;
+}
+
+static int
+gc_verify_heap_pages(rb_objspace_t *objspace)
+{
+ int remembered_old_objects = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ remembered_old_objects += gc_verify_heap_pages_(objspace, &((&heaps[i])->pages));
+ }
+ return remembered_old_objects;
+}
+
+static void
+gc_verify_internal_consistency_(rb_objspace_t *objspace)
+{
+ struct verify_internal_consistency_struct data = {0};
+
+ data.objspace = objspace;
+ gc_report(5, objspace, "gc_verify_internal_consistency: start\n");
+
+ /* check relations */
+ for (size_t i = 0; i < rb_darray_size(objspace->heap_pages.sorted); i++) {
+ struct heap_page *page = rb_darray_get(objspace->heap_pages.sorted, i);
+ short slot_size = page->slot_size;
+
+ uintptr_t start = (uintptr_t)page->start;
+ uintptr_t end = start + page->total_slots * slot_size;
+
+ verify_internal_consistency_i((void *)start, (void *)end, slot_size, &data);
+ }
+
+ if (data.err_count != 0) {
+#if RGENGC_CHECK_MODE >= 5
+ objspace->rgengc.error_count = data.err_count;
+ gc_marks_check(objspace, NULL, NULL);
+ allrefs_dump(objspace);
+#endif
+ rb_bug("gc_verify_internal_consistency: found internal inconsistency.");
+ }
+
+ /* check heap_page status */
+ gc_verify_heap_pages(objspace);
+
+ /* check counters */
+
+ ractor_cache_flush_count(objspace, rb_gc_get_ractor_newobj_cache());
+
+ if (!is_lazy_sweeping(objspace) &&
+ !finalizing &&
+ !rb_gc_multi_ractor_p()) {
+ if (objspace_live_slots(objspace) != data.live_object_count) {
+ fprintf(stderr, "heap_pages_final_slots: %"PRIdSIZE", total_freed_objects: %"PRIdSIZE"\n",
+ total_final_slots_count(objspace), total_freed_objects(objspace));
+ rb_bug("inconsistent live slot number: expect %"PRIuSIZE", but %"PRIuSIZE".",
+ objspace_live_slots(objspace), data.live_object_count);
+ }
+ }
+
+ if (!is_marking(objspace)) {
+ if (objspace->rgengc.old_objects != data.old_object_count) {
+ rb_bug("inconsistent old slot number: expect %"PRIuSIZE", but %"PRIuSIZE".",
+ objspace->rgengc.old_objects, data.old_object_count);
+ }
+ if (objspace->rgengc.uncollectible_wb_unprotected_objects != data.remembered_shady_count) {
+ rb_bug("inconsistent number of wb unprotected objects: expect %"PRIuSIZE", but %"PRIuSIZE".",
+ objspace->rgengc.uncollectible_wb_unprotected_objects, data.remembered_shady_count);
+ }
+ }
+
+ if (!finalizing) {
+ size_t list_count = 0;
+
+ {
+ VALUE z = heap_pages_deferred_final;
+ while (z) {
+ list_count++;
+ z = RZOMBIE(z)->next;
+ }
+ }
+
+ if (total_final_slots_count(objspace) != data.zombie_object_count ||
+ total_final_slots_count(objspace) != list_count) {
+
+ rb_bug("inconsistent finalizing object count:\n"
+ " expect %"PRIuSIZE"\n"
+ " but %"PRIuSIZE" zombies\n"
+ " heap_pages_deferred_final list has %"PRIuSIZE" items.",
+ total_final_slots_count(objspace),
+ data.zombie_object_count,
+ list_count);
+ }
+ }
+
+ gc_report(5, objspace, "gc_verify_internal_consistency: OK\n");
+}
+
+static void
+gc_verify_internal_consistency(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ unsigned int lev = RB_GC_VM_LOCK();
+ {
+ rb_gc_vm_barrier(); // stop other ractors
+
+ unsigned int prev_during_gc = during_gc;
+ during_gc = FALSE; // stop gc here
+ {
+ gc_verify_internal_consistency_(objspace);
+ }
+ during_gc = prev_during_gc;
+ }
+ RB_GC_VM_UNLOCK(lev);
+}
+
+static void
+heap_move_pooled_pages_to_free_pages(rb_heap_t *heap)
+{
+ if (heap->pooled_pages) {
+ if (heap->free_pages) {
+ struct heap_page *free_pages_tail = heap->free_pages;
+ while (free_pages_tail->free_next) {
+ free_pages_tail = free_pages_tail->free_next;
+ }
+ free_pages_tail->free_next = heap->pooled_pages;
+ }
+ else {
+ heap->free_pages = heap->pooled_pages;
+ }
+
+ heap->pooled_pages = NULL;
+ }
+}
+
+static int
+gc_remember_unprotected(rb_objspace_t *objspace, VALUE obj)
+{
+ struct heap_page *page = GET_HEAP_PAGE(obj);
+ bits_t *uncollectible_bits = &page->uncollectible_bits[0];
+
+ if (!MARKED_IN_BITMAP(uncollectible_bits, obj)) {
+ page->flags.has_uncollectible_wb_unprotected_objects = TRUE;
+ MARK_IN_BITMAP(uncollectible_bits, obj);
+ objspace->rgengc.uncollectible_wb_unprotected_objects++;
+
+#if RGENGC_PROFILE > 0
+ objspace->profile.total_remembered_shady_object_count++;
+#if RGENGC_PROFILE >= 2
+ objspace->profile.remembered_shady_object_count_types[BUILTIN_TYPE(obj)]++;
+#endif
+#endif
+ return TRUE;
+ }
+ else {
+ return FALSE;
+ }
+}
+
+static inline void
+gc_marks_wb_unprotected_objects_plane(rb_objspace_t *objspace, uintptr_t p, bits_t bits, short slot_size)
+{
+ if (bits) {
+ do {
+ if (bits & 1) {
+ gc_report(2, objspace, "gc_marks_wb_unprotected_objects: marked shady: %s\n", rb_obj_info((VALUE)p));
+ GC_ASSERT(RVALUE_WB_UNPROTECTED(objspace, (VALUE)p));
+ GC_ASSERT(RVALUE_MARKED(objspace, (VALUE)p));
+ gc_mark_children(objspace, (VALUE)p);
+ }
+ p += slot_size;
+ bits >>= 1;
+ } while (bits);
+ }
+}
+
+static void
+gc_marks_wb_unprotected_objects(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ struct heap_page *page = 0;
+
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ bits_t *mark_bits = page->mark_bits;
+ bits_t *wbun_bits = page->wb_unprotected_bits;
+ uintptr_t p = page->start;
+ short slot_size = page->slot_size;
+ int total_slots = page->total_slots;
+ int bitmap_plane_count = CEILDIV(total_slots, BITS_BITLENGTH);
+ size_t j;
+
+ for (j=0; j<(size_t)bitmap_plane_count; j++) {
+ bits_t bits = mark_bits[j] & wbun_bits[j];
+ gc_marks_wb_unprotected_objects_plane(objspace, p, bits, slot_size);
+ p += BITS_BITLENGTH * slot_size;
+ }
+ }
+
+ gc_mark_stacked_objects_all(objspace);
+}
+
+void
+rb_gc_impl_declare_weak_references(void *objspace_ptr, VALUE obj)
+{
+ FL_SET_RAW(obj, RUBY_FL_WEAK_REFERENCE);
+}
+
+bool
+rb_gc_impl_handle_weak_references_alive_p(void *objspace_ptr, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ bool marked = RVALUE_MARKED(objspace, obj);
+
+ if (marked) {
+ rgengc_check_relation(objspace, obj);
+ }
+
+ return marked;
+}
+
+static void
+gc_update_weak_references(rb_objspace_t *objspace)
+{
+ VALUE *obj_ptr;
+ rb_darray_foreach(objspace->weak_references, i, obj_ptr) {
+ gc_mark_set_parent(objspace, *obj_ptr);
+ rb_gc_handle_weak_references(*obj_ptr);
+ gc_mark_set_parent_invalid(objspace);
+ }
+
+ size_t capa = rb_darray_capa(objspace->weak_references);
+ size_t size = rb_darray_size(objspace->weak_references);
+
+ objspace->profile.weak_references_count = size;
+
+ rb_darray_clear(objspace->weak_references);
+
+ /* If the darray has capacity for more than four times the amount used, we
+ * shrink it down to half of that capacity. */
+ if (capa > size * 4) {
+ rb_darray_resize_capa_without_gc(&objspace->weak_references, size * 2);
+ }
+}
+
+static void
+gc_marks_finish(rb_objspace_t *objspace)
+{
+ /* finish incremental GC */
+ if (is_incremental_marking(objspace)) {
+ if (RGENGC_CHECK_MODE && is_mark_stack_empty(&objspace->mark_stack) == 0) {
+ rb_bug("gc_marks_finish: mark stack is not empty (%"PRIdSIZE").",
+ mark_stack_size(&objspace->mark_stack));
+ }
+
+ mark_roots(objspace, NULL);
+ while (gc_mark_stacked_objects_incremental(objspace, INT_MAX) == false);
+
+#if RGENGC_CHECK_MODE >= 2
+ if (gc_verify_heap_pages(objspace) != 0) {
+ rb_bug("gc_marks_finish (incremental): there are remembered old objects.");
+ }
+#endif
+
+ objspace->flags.during_incremental_marking = FALSE;
+ /* check children of all marked wb-unprotected objects */
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ gc_marks_wb_unprotected_objects(objspace, &heaps[i]);
+ }
+ }
+
+ gc_update_weak_references(objspace);
+
+#if RGENGC_CHECK_MODE >= 2
+ gc_verify_internal_consistency(objspace);
+#endif
+
+#if RGENGC_CHECK_MODE >= 4
+ during_gc = FALSE;
+ gc_marks_check(objspace, gc_check_after_marks_i, "after_marks");
+ during_gc = TRUE;
+#endif
+
+ {
+ const unsigned long r_mul = objspace->live_ractor_cache_count > 8 ? 8 : objspace->live_ractor_cache_count; // upto 8
+
+ size_t total_slots = objspace_available_slots(objspace);
+ size_t sweep_slots = total_slots - objspace->marked_slots; /* will be swept slots */
+ size_t max_free_slots = (size_t)(total_slots * gc_params.heap_free_slots_max_ratio);
+ size_t min_free_slots = (size_t)(total_slots * gc_params.heap_free_slots_min_ratio);
+ if (min_free_slots < gc_params.heap_free_slots * r_mul) {
+ min_free_slots = gc_params.heap_free_slots * r_mul;
+ }
+
+ int full_marking = is_full_marking(objspace);
+
+ GC_ASSERT(objspace_available_slots(objspace) >= objspace->marked_slots);
+
+ /* Setup freeable slots. */
+ size_t total_init_slots = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ total_init_slots += (gc_params.heap_init_bytes / heaps[i].slot_size) * r_mul;
+ }
+
+ if (max_free_slots < total_init_slots) {
+ max_free_slots = total_init_slots;
+ }
+
+ /* Approximate freeable pages using the average slots-per-pages across all heaps */
+ if (sweep_slots > max_free_slots) {
+ size_t excess_slots = sweep_slots - max_free_slots;
+ size_t total_heap_pages = heap_eden_total_pages(objspace);
+ heap_pages_freeable_pages = total_heap_pages > 0
+ ? excess_slots * total_heap_pages / total_slots
+ : 0;
+ }
+ else {
+ heap_pages_freeable_pages = 0;
+ }
+
+ if (objspace->heap_pages.allocatable_bytes == 0 && sweep_slots < min_free_slots) {
+ if (!full_marking && sweep_slots < min_free_slots * 7 / 8) {
+ if (objspace->profile.count - objspace->rgengc.last_major_gc < RVALUE_OLD_AGE) {
+ full_marking = TRUE;
+ }
+ else {
+ gc_report(1, objspace, "gc_marks_finish: next is full GC!!)\n");
+ gc_needs_major_flags |= GPR_FLAG_MAJOR_BY_NOFREE;
+ }
+ }
+
+ if (full_marking) {
+ heap_allocatable_bytes_expand(objspace, NULL, sweep_slots, total_slots, heaps[0].slot_size);
+ }
+ }
+
+ if (full_marking) {
+ /* See the comment about RUBY_GC_HEAP_OLDOBJECT_LIMIT_FACTOR */
+ const double r = gc_params.oldobject_limit_factor;
+ objspace->rgengc.uncollectible_wb_unprotected_objects_limit = MAX(
+ (size_t)(objspace->rgengc.uncollectible_wb_unprotected_objects * r),
+ (size_t)(objspace->rgengc.old_objects * gc_params.uncollectible_wb_unprotected_objects_limit_ratio)
+ );
+ objspace->rgengc.old_objects_limit = (size_t)(objspace->rgengc.old_objects * r);
+ }
+
+ if (objspace->rgengc.uncollectible_wb_unprotected_objects > objspace->rgengc.uncollectible_wb_unprotected_objects_limit) {
+ gc_needs_major_flags |= GPR_FLAG_MAJOR_BY_SHADY;
+ }
+ if (objspace->rgengc.old_objects > objspace->rgengc.old_objects_limit) {
+ gc_needs_major_flags |= GPR_FLAG_MAJOR_BY_OLDGEN;
+ }
+
+ gc_report(1, objspace, "gc_marks_finish (marks %"PRIdSIZE" objects, "
+ "old %"PRIdSIZE" objects, total %"PRIdSIZE" slots, "
+ "sweep %"PRIdSIZE" slots, allocatable %"PRIdSIZE" bytes, next GC: %s)\n",
+ objspace->marked_slots, objspace->rgengc.old_objects, objspace_available_slots(objspace), sweep_slots, objspace->heap_pages.allocatable_bytes,
+ gc_needs_major_flags ? "major" : "minor");
+ }
+
+ // TODO: refactor so we don't need to call this
+ rb_ractor_finish_marking();
+
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_END_MARK);
+}
+
+static bool
+gc_compact_heap_cursors_met_p(rb_heap_t *heap)
+{
+ return heap->sweeping_page == heap->compact_cursor;
+}
+
+
+static rb_heap_t *
+gc_compact_destination_pool(rb_objspace_t *objspace, rb_heap_t *src_pool, VALUE obj)
+{
+ size_t obj_size = rb_gc_obj_optimal_size(obj);
+ if (obj_size == 0) {
+ return src_pool;
+ }
+
+ GC_ASSERT(rb_gc_impl_size_allocatable_p(obj_size));
+
+ size_t idx = heap_idx_for_size(obj_size);
+
+ return &heaps[idx];
+}
+
+static bool
+gc_compact_move(rb_objspace_t *objspace, rb_heap_t *heap, VALUE src)
+{
+ GC_ASSERT(BUILTIN_TYPE(src) != T_MOVED);
+ GC_ASSERT(gc_is_moveable_obj(objspace, src));
+
+ rb_heap_t *dest_pool = gc_compact_destination_pool(objspace, heap, src);
+ if (gc_compact_heap_cursors_met_p(dest_pool)) {
+ return dest_pool != heap;
+ }
+
+ while (!try_move(objspace, dest_pool, dest_pool->free_pages, src)) {
+ struct gc_sweep_context ctx = {
+ .page = dest_pool->sweeping_page,
+ .final_slots = 0,
+ .freed_slots = 0,
+ .empty_slots = 0,
+ };
+
+ /* The page of src could be partially compacted, so it may contain
+ * T_MOVED. Sweeping a page may read objects on this page, so we
+ * need to lock the page. */
+ lock_page_body(objspace, GET_PAGE_BODY(src));
+ gc_sweep_page(objspace, dest_pool, &ctx);
+ unlock_page_body(objspace, GET_PAGE_BODY(src));
+
+ if (dest_pool->sweeping_page->free_slots > 0) {
+ heap_add_freepage(dest_pool, dest_pool->sweeping_page);
+ }
+
+ dest_pool->sweeping_page = ccan_list_next(&dest_pool->pages, dest_pool->sweeping_page, page_node);
+ if (gc_compact_heap_cursors_met_p(dest_pool)) {
+ return dest_pool != heap;
+ }
+ }
+
+ return true;
+}
+
+static bool
+gc_compact_plane(rb_objspace_t *objspace, rb_heap_t *heap, uintptr_t p, bits_t bitset, struct heap_page *page)
+{
+ short slot_size = page->slot_size;
+
+ do {
+ VALUE vp = (VALUE)p;
+ GC_ASSERT(vp % sizeof(VALUE) == 0);
+
+ if (bitset & 1) {
+ objspace->rcompactor.considered_count_table[BUILTIN_TYPE(vp)]++;
+
+ if (gc_is_moveable_obj(objspace, vp)) {
+ if (!gc_compact_move(objspace, heap, vp)) {
+ //the cursors met. bubble up
+ return false;
+ }
+ }
+ }
+ p += slot_size;
+ bitset >>= 1;
+ } while (bitset);
+
+ return true;
+}
+
+// Iterate up all the objects in page, moving them to where they want to go
+static bool
+gc_compact_page(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *page)
+{
+ GC_ASSERT(page == heap->compact_cursor);
+
+ bits_t *mark_bits, *pin_bits;
+ bits_t bitset;
+ uintptr_t p = page->start;
+ short slot_size = page->slot_size;
+ int total_slots = page->total_slots;
+ int bitmap_plane_count = CEILDIV(total_slots, BITS_BITLENGTH);
+
+ mark_bits = page->mark_bits;
+ pin_bits = page->pinned_bits;
+
+ for (int j = 0; j < bitmap_plane_count; j++) {
+ // objects that can be moved are marked and not pinned
+ bitset = (mark_bits[j] & ~pin_bits[j]);
+ if (bitset) {
+ if (!gc_compact_plane(objspace, heap, (uintptr_t)p, bitset, page))
+ return false;
+ }
+ p += BITS_BITLENGTH * slot_size;
+ }
+
+ return true;
+}
+
+static bool
+gc_compact_all_compacted_p(rb_objspace_t *objspace)
+{
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+
+ if (heap->total_pages > 0 &&
+ !gc_compact_heap_cursors_met_p(heap)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static void
+gc_sweep_compact(rb_objspace_t *objspace)
+{
+ gc_compact_start(objspace);
+#if RGENGC_CHECK_MODE >= 2
+ gc_verify_internal_consistency(objspace);
+#endif
+
+ while (!gc_compact_all_compacted_p(objspace)) {
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+
+ if (gc_compact_heap_cursors_met_p(heap)) {
+ continue;
+ }
+
+ struct heap_page *start_page = heap->compact_cursor;
+
+ if (!gc_compact_page(objspace, heap, start_page)) {
+ lock_page_body(objspace, start_page->body);
+
+ continue;
+ }
+
+ // If we get here, we've finished moving all objects on the compact_cursor page
+ // So we can lock it and move the cursor on to the next one.
+ lock_page_body(objspace, start_page->body);
+ heap->compact_cursor = ccan_list_prev(&heap->pages, heap->compact_cursor, page_node);
+ }
+ }
+
+ gc_compact_finish(objspace);
+
+#if RGENGC_CHECK_MODE >= 2
+ gc_verify_internal_consistency(objspace);
+#endif
+}
+
+static void
+gc_marks_rest(rb_objspace_t *objspace)
+{
+ gc_report(1, objspace, "gc_marks_rest\n");
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ (&heaps[i])->pooled_pages = NULL;
+ }
+
+ if (is_incremental_marking(objspace)) {
+ while (gc_mark_stacked_objects_incremental(objspace, INT_MAX) == FALSE);
+ }
+ else {
+ gc_mark_stacked_objects_all(objspace);
+ }
+
+ gc_marks_finish(objspace);
+}
+
+static bool
+gc_marks_step(rb_objspace_t *objspace, size_t slots)
+{
+ bool marking_finished = false;
+
+ GC_ASSERT(is_marking(objspace));
+ if (gc_mark_stacked_objects_incremental(objspace, slots)) {
+ gc_marks_finish(objspace);
+
+ marking_finished = true;
+ }
+
+ return marking_finished;
+}
+
+static bool
+gc_marks_continue(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ GC_ASSERT(dont_gc_val() == FALSE || objspace->profile.latest_gc_info & GPR_FLAG_METHOD);
+ bool marking_finished = true;
+
+ gc_marking_enter(objspace);
+
+ if (heap->free_pages) {
+ gc_report(2, objspace, "gc_marks_continue: has pooled pages");
+
+ marking_finished = gc_marks_step(objspace, objspace->rincgc.step_slots);
+ }
+ else {
+ gc_report(2, objspace, "gc_marks_continue: no more pooled pages (stack depth: %"PRIdSIZE").\n",
+ mark_stack_size(&objspace->mark_stack));
+ heap->force_incremental_marking_finish_count++;
+ gc_marks_rest(objspace);
+ }
+
+ gc_marking_exit(objspace);
+
+ return marking_finished;
+}
+
+static void
+gc_marks_start(rb_objspace_t *objspace, int full_mark)
+{
+ /* start marking */
+ gc_report(1, objspace, "gc_marks_start: (%s)\n", full_mark ? "full" : "minor");
+ gc_mode_transition(objspace, gc_mode_marking);
+
+ if (full_mark) {
+ size_t incremental_marking_steps = (objspace->rincgc.pooled_slots / INCREMENTAL_MARK_STEP_ALLOCATIONS) + 1;
+ objspace->rincgc.step_slots = (objspace->marked_slots * 2) / incremental_marking_steps;
+
+ if (0) fprintf(stderr, "objspace->marked_slots: %"PRIdSIZE", "
+ "objspace->rincgc.pooled_page_num: %"PRIdSIZE", "
+ "objspace->rincgc.step_slots: %"PRIdSIZE", \n",
+ objspace->marked_slots, objspace->rincgc.pooled_slots, objspace->rincgc.step_slots);
+ objspace->flags.during_minor_gc = FALSE;
+ if (ruby_enable_autocompact) {
+ objspace->flags.during_compacting |= TRUE;
+ }
+ objspace->profile.major_gc_count++;
+ objspace->rgengc.uncollectible_wb_unprotected_objects = 0;
+ objspace->rgengc.old_objects = 0;
+ objspace->rgengc.last_major_gc = objspace->profile.count;
+ objspace->marked_slots = 0;
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ rgengc_mark_and_rememberset_clear(objspace, heap);
+ heap_move_pooled_pages_to_free_pages(heap);
+
+ if (objspace->flags.during_compacting) {
+ struct heap_page *page = NULL;
+
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ page->pinned_slots = 0;
+ }
+ }
+ }
+ }
+ else {
+ objspace->flags.during_minor_gc = TRUE;
+ objspace->marked_slots =
+ objspace->rgengc.old_objects + objspace->rgengc.uncollectible_wb_unprotected_objects; /* uncollectible objects are marked already */
+ objspace->profile.minor_gc_count++;
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rgengc_rememberset_mark(objspace, &heaps[i]);
+ }
+ }
+
+ mark_roots(objspace, NULL);
+
+ gc_report(1, objspace, "gc_marks_start: (%s) end, stack in %"PRIdSIZE"\n",
+ full_mark ? "full" : "minor", mark_stack_size(&objspace->mark_stack));
+}
+
+static bool
+gc_marks(rb_objspace_t *objspace, int full_mark)
+{
+ gc_prof_mark_timer_start(objspace);
+ gc_marking_enter(objspace);
+
+ bool marking_finished = false;
+
+ /* setup marking */
+
+ gc_marks_start(objspace, full_mark);
+ if (!is_incremental_marking(objspace)) {
+ gc_marks_rest(objspace);
+ marking_finished = true;
+ }
+
+#if RGENGC_PROFILE > 0
+ if (gc_prof_record(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+ record->old_objects = objspace->rgengc.old_objects;
+ }
+#endif
+
+ gc_marking_exit(objspace);
+ gc_prof_mark_timer_stop(objspace);
+
+ return marking_finished;
+}
+
+/* RGENGC */
+
+static void
+gc_report_body(int level, rb_objspace_t *objspace, const char *fmt, ...)
+{
+ if (level <= RGENGC_DEBUG) {
+ char buf[1024];
+ FILE *out = stderr;
+ va_list args;
+ const char *status = " ";
+
+ if (during_gc) {
+ status = is_full_marking(objspace) ? "+" : "-";
+ }
+ else {
+ if (is_lazy_sweeping(objspace)) {
+ status = "S";
+ }
+ if (is_incremental_marking(objspace)) {
+ status = "M";
+ }
+ }
+
+ va_start(args, fmt);
+ vsnprintf(buf, 1024, fmt, args);
+ va_end(args);
+
+ fprintf(out, "%s|", status);
+ fputs(buf, out);
+ }
+}
+
+/* bit operations */
+
+static int
+rgengc_remembersetbits_set(rb_objspace_t *objspace, VALUE obj)
+{
+ struct heap_page *page = GET_HEAP_PAGE(obj);
+ bits_t *bits = &page->remembered_bits[0];
+
+ if (MARKED_IN_BITMAP(bits, obj)) {
+ return FALSE;
+ }
+ else {
+ page->flags.has_remembered_objects = TRUE;
+ MARK_IN_BITMAP(bits, obj);
+ return TRUE;
+ }
+}
+
+/* wb, etc */
+
+/* return FALSE if already remembered */
+static int
+rgengc_remember(rb_objspace_t *objspace, VALUE obj)
+{
+ gc_report(6, objspace, "rgengc_remember: %s %s\n", rb_obj_info(obj),
+ RVALUE_REMEMBERED(objspace, obj) ? "was already remembered" : "is remembered now");
+
+ check_rvalue_consistency(objspace, obj);
+
+ if (RGENGC_CHECK_MODE) {
+ if (RVALUE_WB_UNPROTECTED(objspace, obj)) rb_bug("rgengc_remember: %s is not wb protected.", rb_obj_info(obj));
+ }
+
+#if RGENGC_PROFILE > 0
+ if (!RVALUE_REMEMBERED(objspace, obj)) {
+ if (RVALUE_WB_UNPROTECTED(objspace, obj) == 0) {
+ objspace->profile.total_remembered_normal_object_count++;
+#if RGENGC_PROFILE >= 2
+ objspace->profile.remembered_normal_object_count_types[BUILTIN_TYPE(obj)]++;
+#endif
+ }
+ }
+#endif /* RGENGC_PROFILE > 0 */
+
+ return rgengc_remembersetbits_set(objspace, obj);
+}
+
+#ifndef PROFILE_REMEMBERSET_MARK
+#define PROFILE_REMEMBERSET_MARK 0
+#endif
+
+static inline void
+rgengc_rememberset_mark_plane(rb_objspace_t *objspace, uintptr_t p, bits_t bitset, short slot_size)
+{
+ if (bitset) {
+ do {
+ if (bitset & 1) {
+ VALUE obj = (VALUE)p;
+ gc_report(2, objspace, "rgengc_rememberset_mark: mark %s\n", rb_obj_info(obj));
+ GC_ASSERT(RVALUE_UNCOLLECTIBLE(objspace, obj));
+ GC_ASSERT(RVALUE_OLD_P(objspace, obj) || RVALUE_WB_UNPROTECTED(objspace, obj));
+
+ gc_mark_children(objspace, obj);
+
+ if (RB_FL_TEST_RAW(obj, RUBY_FL_WEAK_REFERENCE)) {
+ rb_darray_append_without_gc(&objspace->weak_references, obj);
+ }
+ }
+ p += slot_size;
+ bitset >>= 1;
+ } while (bitset);
+ }
+}
+
+static void
+rgengc_rememberset_mark(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ size_t j;
+ struct heap_page *page = 0;
+#if PROFILE_REMEMBERSET_MARK
+ int has_old = 0, has_shady = 0, has_both = 0, skip = 0;
+#endif
+ gc_report(1, objspace, "rgengc_rememberset_mark: start\n");
+
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ if (page->flags.has_remembered_objects | page->flags.has_uncollectible_wb_unprotected_objects) {
+ uintptr_t p = page->start;
+ short slot_size = page->slot_size;
+ int total_slots = page->total_slots;
+ int bitmap_plane_count = CEILDIV(total_slots, BITS_BITLENGTH);
+ bits_t bitset, bits[HEAP_PAGE_BITMAP_LIMIT];
+ bits_t *remembered_bits = page->remembered_bits;
+ bits_t *uncollectible_bits = page->uncollectible_bits;
+ bits_t *wb_unprotected_bits = page->wb_unprotected_bits;
+#if PROFILE_REMEMBERSET_MARK
+ if (page->flags.has_remembered_objects && page->flags.has_uncollectible_wb_unprotected_objects) has_both++;
+ else if (page->flags.has_remembered_objects) has_old++;
+ else if (page->flags.has_uncollectible_wb_unprotected_objects) has_shady++;
+#endif
+ for (j=0; j < (size_t)bitmap_plane_count; j++) {
+ bits[j] = remembered_bits[j] | (uncollectible_bits[j] & wb_unprotected_bits[j]);
+ remembered_bits[j] = 0;
+ }
+ page->flags.has_remembered_objects = FALSE;
+
+ for (j=0; j < (size_t)bitmap_plane_count; j++) {
+ bitset = bits[j];
+ rgengc_rememberset_mark_plane(objspace, p, bitset, slot_size);
+ p += BITS_BITLENGTH * slot_size;
+ }
+ }
+#if PROFILE_REMEMBERSET_MARK
+ else {
+ skip++;
+ }
+#endif
+ }
+
+#if PROFILE_REMEMBERSET_MARK
+ fprintf(stderr, "%d\t%d\t%d\t%d\n", has_both, has_old, has_shady, skip);
+#endif
+ gc_report(1, objspace, "rgengc_rememberset_mark: finished\n");
+}
+
+static void
+rgengc_mark_and_rememberset_clear(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ struct heap_page *page = 0;
+
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ memset(&page->mark_bits[0], 0, HEAP_PAGE_BITMAP_SIZE);
+ memset(&page->uncollectible_bits[0], 0, HEAP_PAGE_BITMAP_SIZE);
+ memset(&page->marking_bits[0], 0, HEAP_PAGE_BITMAP_SIZE);
+ memset(&page->remembered_bits[0], 0, HEAP_PAGE_BITMAP_SIZE);
+ memset(&page->pinned_bits[0], 0, HEAP_PAGE_BITMAP_SIZE);
+ page->flags.has_uncollectible_wb_unprotected_objects = FALSE;
+ page->flags.has_remembered_objects = FALSE;
+ }
+}
+
+/* RGENGC: APIs */
+
+NOINLINE(static void gc_writebarrier_generational(VALUE a, VALUE b, rb_objspace_t *objspace));
+
+static void
+gc_writebarrier_generational(VALUE a, VALUE b, rb_objspace_t *objspace)
+{
+ if (RGENGC_CHECK_MODE) {
+ if (!RVALUE_OLD_P(objspace, a)) rb_bug("gc_writebarrier_generational: %s is not an old object.", rb_obj_info(a));
+ if ( RVALUE_OLD_P(objspace, b)) rb_bug("gc_writebarrier_generational: %s is an old object.", rb_obj_info(b));
+ if (is_incremental_marking(objspace)) rb_bug("gc_writebarrier_generational: called while incremental marking: %s -> %s", rb_obj_info(a), rb_obj_info(b));
+ }
+
+ /* mark `a' and remember (default behavior) */
+ if (!RVALUE_REMEMBERED(objspace, a)) {
+ int lev = RB_GC_VM_LOCK_NO_BARRIER();
+ {
+ rgengc_remember(objspace, a);
+ }
+ RB_GC_VM_UNLOCK_NO_BARRIER(lev);
+
+ gc_report(1, objspace, "gc_writebarrier_generational: %s (remembered) -> %s\n", rb_obj_info(a), rb_obj_info(b));
+ }
+
+ check_rvalue_consistency(objspace, a);
+ check_rvalue_consistency(objspace, b);
+}
+
+static void
+gc_mark_from(rb_objspace_t *objspace, VALUE obj, VALUE parent)
+{
+ gc_mark_set_parent(objspace, parent);
+ rgengc_check_relation(objspace, obj);
+ if (gc_mark_set(objspace, obj) != FALSE) {
+ gc_aging(objspace, obj);
+ gc_grey(objspace, obj);
+ }
+ gc_mark_set_parent_invalid(objspace);
+}
+
+NOINLINE(static void gc_writebarrier_incremental(VALUE a, VALUE b, rb_objspace_t *objspace));
+
+static void
+gc_writebarrier_incremental(VALUE a, VALUE b, rb_objspace_t *objspace)
+{
+ gc_report(2, objspace, "gc_writebarrier_incremental: [LG] %p -> %s\n", (void *)a, rb_obj_info(b));
+
+ if (RVALUE_BLACK_P(objspace, a)) {
+ if (RVALUE_WHITE_P(objspace, b)) {
+ if (!RVALUE_WB_UNPROTECTED(objspace, a)) {
+ gc_report(2, objspace, "gc_writebarrier_incremental: [IN] %p -> %s\n", (void *)a, rb_obj_info(b));
+ gc_mark_from(objspace, b, a);
+ }
+ }
+ else if (RVALUE_OLD_P(objspace, a) && !RVALUE_OLD_P(objspace, b)) {
+ rgengc_remember(objspace, a);
+ }
+
+ if (RB_UNLIKELY(objspace->flags.during_compacting)) {
+ MARK_IN_BITMAP(GET_HEAP_PINNED_BITS(b), b);
+ }
+ }
+}
+
+void
+rb_gc_impl_writebarrier(void *objspace_ptr, VALUE a, VALUE b)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+#if RGENGC_CHECK_MODE
+ if (SPECIAL_CONST_P(a)) rb_bug("rb_gc_writebarrier: a is special const: %"PRIxVALUE, a);
+ if (SPECIAL_CONST_P(b)) rb_bug("rb_gc_writebarrier: b is special const: %"PRIxVALUE, b);
+#else
+ RBIMPL_ASSERT_OR_ASSUME(!SPECIAL_CONST_P(a));
+ RBIMPL_ASSERT_OR_ASSUME(!SPECIAL_CONST_P(b));
+#endif
+
+ GC_ASSERT(!during_gc);
+ GC_ASSERT(RB_BUILTIN_TYPE(a) != T_NONE);
+ GC_ASSERT(RB_BUILTIN_TYPE(a) != T_MOVED);
+ GC_ASSERT(RB_BUILTIN_TYPE(a) != T_ZOMBIE);
+ GC_ASSERT(RB_BUILTIN_TYPE(b) != T_NONE);
+ GC_ASSERT(RB_BUILTIN_TYPE(b) != T_MOVED);
+ GC_ASSERT(RB_BUILTIN_TYPE(b) != T_ZOMBIE);
+
+ retry:
+ if (!is_incremental_marking(objspace)) {
+ if (!RVALUE_OLD_P(objspace, a) || RVALUE_OLD_P(objspace, b)) {
+ // do nothing
+ }
+ else {
+ gc_writebarrier_generational(a, b, objspace);
+ }
+ }
+ else {
+ bool retry = false;
+ /* slow path */
+ int lev = RB_GC_VM_LOCK_NO_BARRIER();
+ {
+ if (is_incremental_marking(objspace)) {
+ gc_writebarrier_incremental(a, b, objspace);
+ }
+ else {
+ retry = true;
+ }
+ }
+ RB_GC_VM_UNLOCK_NO_BARRIER(lev);
+
+ if (retry) goto retry;
+ }
+ return;
+}
+
+void
+rb_gc_impl_writebarrier_unprotect(void *objspace_ptr, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (RVALUE_WB_UNPROTECTED(objspace, obj)) {
+ return;
+ }
+ else {
+ gc_report(2, objspace, "rb_gc_writebarrier_unprotect: %s %s\n", rb_obj_info(obj),
+ RVALUE_REMEMBERED(objspace, obj) ? " (already remembered)" : "");
+
+ unsigned int lev = RB_GC_VM_LOCK_NO_BARRIER();
+ {
+ if (RVALUE_OLD_P(objspace, obj)) {
+ gc_report(1, objspace, "rb_gc_writebarrier_unprotect: %s\n", rb_obj_info(obj));
+ RVALUE_DEMOTE(objspace, obj);
+ gc_mark_set(objspace, obj);
+ gc_remember_unprotected(objspace, obj);
+
+#if RGENGC_PROFILE
+ objspace->profile.total_shade_operation_count++;
+#if RGENGC_PROFILE >= 2
+ objspace->profile.shade_operation_count_types[BUILTIN_TYPE(obj)]++;
+#endif /* RGENGC_PROFILE >= 2 */
+#endif /* RGENGC_PROFILE */
+ }
+ else {
+ RVALUE_AGE_RESET(obj);
+ }
+
+ RB_DEBUG_COUNTER_INC(obj_wb_unprotect);
+ MARK_IN_BITMAP(GET_HEAP_WB_UNPROTECTED_BITS(obj), obj);
+ }
+ RB_GC_VM_UNLOCK_NO_BARRIER(lev);
+ }
+}
+
+void
+rb_gc_impl_copy_attributes(void *objspace_ptr, VALUE dest, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (RVALUE_WB_UNPROTECTED(objspace, obj)) {
+ rb_gc_impl_writebarrier_unprotect(objspace, dest);
+ }
+ rb_gc_impl_copy_finalizer(objspace, dest, obj);
+}
+
+const char *
+rb_gc_impl_active_gc_name(void)
+{
+ return "default";
+}
+
+void
+rb_gc_impl_writebarrier_remember(void *objspace_ptr, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ gc_report(1, objspace, "rb_gc_writebarrier_remember: %s\n", rb_obj_info(obj));
+
+ if (is_incremental_marking(objspace) || RVALUE_OLD_P(objspace, obj)) {
+ int lev = RB_GC_VM_LOCK_NO_BARRIER();
+ {
+ if (is_incremental_marking(objspace)) {
+ if (RVALUE_BLACK_P(objspace, obj)) {
+ gc_grey(objspace, obj);
+ }
+ }
+ else if (RVALUE_OLD_P(objspace, obj)) {
+ rgengc_remember(objspace, obj);
+ }
+ }
+ RB_GC_VM_UNLOCK_NO_BARRIER(lev);
+ }
+}
+
+struct rb_gc_object_metadata_names {
+ // Must be ID only
+ ID ID_wb_protected, ID_age, ID_old, ID_uncollectible, ID_marking,
+ ID_marked, ID_pinned, ID_remembered, ID_object_id, ID_shareable;
+};
+
+#define RB_GC_OBJECT_METADATA_ENTRY_COUNT (sizeof(struct rb_gc_object_metadata_names) / sizeof(ID))
+static struct rb_gc_object_metadata_entry object_metadata_entries[RB_GC_OBJECT_METADATA_ENTRY_COUNT + 1];
+
+struct rb_gc_object_metadata_entry *
+rb_gc_impl_object_metadata(void *objspace_ptr, VALUE obj)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ size_t n = 0;
+ static struct rb_gc_object_metadata_names names;
+
+ if (!names.ID_marked) {
+#define I(s) names.ID_##s = rb_intern(#s)
+ I(wb_protected);
+ I(age);
+ I(old);
+ I(uncollectible);
+ I(marking);
+ I(marked);
+ I(pinned);
+ I(remembered);
+ I(object_id);
+ I(shareable);
+#undef I
+ }
+
+#define SET_ENTRY(na, v) do { \
+ GC_ASSERT(n <= RB_GC_OBJECT_METADATA_ENTRY_COUNT); \
+ object_metadata_entries[n].name = names.ID_##na; \
+ object_metadata_entries[n].val = v; \
+ n++; \
+} while (0)
+
+ if (!RVALUE_WB_UNPROTECTED(objspace, obj)) SET_ENTRY(wb_protected, Qtrue);
+ SET_ENTRY(age, INT2FIX(RVALUE_AGE_GET(obj)));
+ if (RVALUE_OLD_P(objspace, obj)) SET_ENTRY(old, Qtrue);
+ if (RVALUE_UNCOLLECTIBLE(objspace, obj)) SET_ENTRY(uncollectible, Qtrue);
+ if (RVALUE_MARKING(objspace, obj)) SET_ENTRY(marking, Qtrue);
+ if (RVALUE_MARKED(objspace, obj)) SET_ENTRY(marked, Qtrue);
+ if (RVALUE_PINNED(objspace, obj)) SET_ENTRY(pinned, Qtrue);
+ if (RVALUE_REMEMBERED(objspace, obj)) SET_ENTRY(remembered, Qtrue);
+ if (rb_obj_id_p(obj)) SET_ENTRY(object_id, rb_obj_id(obj));
+ if (FL_TEST(obj, FL_SHAREABLE)) SET_ENTRY(shareable, Qtrue);
+
+ object_metadata_entries[n].name = 0;
+ object_metadata_entries[n].val = 0;
+#undef SET_ENTRY
+
+ return object_metadata_entries;
+}
+
+void *
+rb_gc_impl_ractor_cache_alloc(void *objspace_ptr, void *ractor)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ objspace->live_ractor_cache_count++;
+
+ return calloc1(sizeof(rb_ractor_newobj_cache_t));
+}
+
+void
+rb_gc_impl_ractor_cache_free(void *objspace_ptr, void *cache)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ objspace->live_ractor_cache_count--;
+ gc_ractor_newobj_cache_clear(cache, NULL);
+ free(cache);
+}
+
+static void
+heap_ready_to_gc(rb_objspace_t *objspace, rb_heap_t *heap)
+{
+ if (!heap->free_pages) {
+ if (!heap_page_allocate_and_initialize(objspace, heap)) {
+ objspace->heap_pages.allocatable_bytes = HEAP_PAGE_SIZE;
+ heap_page_allocate_and_initialize(objspace, heap);
+ }
+ }
+}
+
+static int
+ready_to_gc(rb_objspace_t *objspace)
+{
+ if (dont_gc_val() || during_gc) {
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ heap_ready_to_gc(objspace, heap);
+ }
+ return FALSE;
+ }
+ else {
+ return TRUE;
+ }
+}
+
+static void
+gc_reset_malloc_info(rb_objspace_t *objspace, bool full_mark)
+{
+ gc_prof_set_malloc_info(objspace);
+ {
+ int64_t inc = gc_malloc_counters_increase(objspace, &objspace->malloc_counters.counters);
+ size_t old_limit = malloc_limit;
+
+ /* A net-negative `inc` (more freed than malloc'd since last GC) is
+ * treated the same as "allocated less than malloc_limit".
+ * This matches what we were doing pre-monotonic counters, but is it right? */
+ if (inc > 0 && (size_t)inc > malloc_limit) {
+ malloc_limit = (size_t)((size_t)inc * gc_params.malloc_limit_growth_factor);
+ if (malloc_limit > gc_params.malloc_limit_max) {
+ malloc_limit = gc_params.malloc_limit_max;
+ }
+ }
+ else {
+ malloc_limit = (size_t)(malloc_limit * 0.98); /* magic number */
+ if (malloc_limit < gc_params.malloc_limit_min) {
+ malloc_limit = gc_params.malloc_limit_min;
+ }
+ }
+
+ if (0) {
+ if (old_limit != malloc_limit) {
+ fprintf(stderr, "[%"PRIuSIZE"] malloc_limit: %"PRIuSIZE" -> %"PRIuSIZE"\n",
+ rb_gc_count(), old_limit, malloc_limit);
+ }
+ else {
+ fprintf(stderr, "[%"PRIuSIZE"] malloc_limit: not changed (%"PRIuSIZE")\n",
+ rb_gc_count(), malloc_limit);
+ }
+ }
+ }
+
+ /* reset oldmalloc info */
+#if RGENGC_ESTIMATE_OLDMALLOC
+ if (!full_mark) {
+ /* Don't snapshot on minor GC: oldmalloc_increase is meant to
+ * accumulate across minor GCs and only reset at major GC. */
+ int64_t oldmalloc_increase = gc_malloc_counters_increase(objspace, &objspace->malloc_counters.oldcounters);
+ if (oldmalloc_increase > 0 &&
+ (uint64_t)oldmalloc_increase > objspace->rgengc.oldmalloc_increase_limit) {
+ gc_needs_major_flags |= GPR_FLAG_MAJOR_BY_OLDMALLOC;
+ objspace->rgengc.oldmalloc_increase_limit =
+ (size_t)(objspace->rgengc.oldmalloc_increase_limit * gc_params.oldmalloc_limit_growth_factor);
+
+ if (objspace->rgengc.oldmalloc_increase_limit > gc_params.oldmalloc_limit_max) {
+ objspace->rgengc.oldmalloc_increase_limit = gc_params.oldmalloc_limit_max;
+ }
+ }
+
+ if (0) fprintf(stderr, "%"PRIdSIZE"\t%d\t%"PRId64"\t%"PRIuSIZE"\t%"PRIdSIZE"\n",
+ rb_gc_count(),
+ gc_needs_major_flags,
+ oldmalloc_increase,
+ objspace->rgengc.oldmalloc_increase_limit,
+ gc_params.oldmalloc_limit_max);
+ }
+ else {
+ if ((objspace->profile.latest_gc_info & GPR_FLAG_MAJOR_BY_OLDMALLOC) == 0) {
+ objspace->rgengc.oldmalloc_increase_limit =
+ (size_t)(objspace->rgengc.oldmalloc_increase_limit / ((gc_params.oldmalloc_limit_growth_factor - 1)/10 + 1));
+ if (objspace->rgengc.oldmalloc_increase_limit < gc_params.oldmalloc_limit_min) {
+ objspace->rgengc.oldmalloc_increase_limit = gc_params.oldmalloc_limit_min;
+ }
+ }
+ }
+#endif
+}
+
+static int
+garbage_collect(rb_objspace_t *objspace, unsigned int reason)
+{
+ int ret;
+
+ int lev = RB_GC_VM_LOCK();
+ {
+#if GC_PROFILE_MORE_DETAIL
+ objspace->profile.prepare_time = getrusage_time();
+#endif
+
+ gc_rest(objspace);
+
+#if GC_PROFILE_MORE_DETAIL
+ objspace->profile.prepare_time = getrusage_time() - objspace->profile.prepare_time;
+#endif
+
+ ret = gc_start(objspace, reason);
+ }
+ RB_GC_VM_UNLOCK(lev);
+
+ return ret;
+}
+
+static int
+gc_start(rb_objspace_t *objspace, unsigned int reason)
+{
+ unsigned int do_full_mark = !!(reason & GPR_FLAG_FULL_MARK);
+
+ if (!rb_darray_size(objspace->heap_pages.sorted)) return TRUE; /* heap is not ready */
+ if (!(reason & GPR_FLAG_METHOD) && !ready_to_gc(objspace)) return TRUE; /* GC is not allowed */
+
+ rb_gc_initialize_vm_context(&objspace->vm_context);
+
+ GC_ASSERT(gc_mode(objspace) == gc_mode_none, "gc_mode is %s\n", gc_mode_name(gc_mode(objspace)));
+ GC_ASSERT(!is_lazy_sweeping(objspace));
+ GC_ASSERT(!is_incremental_marking(objspace));
+
+ unsigned int lock_lev;
+ gc_enter(objspace, gc_enter_event_start, &lock_lev);
+
+ /* reason may be clobbered, later, so keep set immediate_sweep here */
+ objspace->flags.immediate_sweep = !!(reason & GPR_FLAG_IMMEDIATE_SWEEP);
+
+#if RGENGC_CHECK_MODE >= 2
+ gc_verify_internal_consistency(objspace);
+#endif
+
+ if (ruby_gc_stressful) {
+ int flag = FIXNUM_P(ruby_gc_stress_mode) ? FIX2INT(ruby_gc_stress_mode) : 0;
+
+ if ((flag & (1 << gc_stress_no_major)) == 0) {
+ do_full_mark = TRUE;
+ }
+
+ objspace->flags.immediate_sweep = !(flag & (1<<gc_stress_no_immediate_sweep));
+ }
+
+ if (gc_needs_major_flags) {
+ reason |= gc_needs_major_flags;
+ do_full_mark = TRUE;
+ }
+
+ /* if major gc has been disabled, never do a full mark */
+ if (!gc_config_full_mark_val) {
+ do_full_mark = FALSE;
+ }
+ gc_needs_major_flags = GPR_FLAG_NONE;
+
+ if (do_full_mark && (reason & GPR_FLAG_MAJOR_MASK) == 0) {
+ reason |= GPR_FLAG_MAJOR_BY_FORCE; /* GC by CAPI, METHOD, and so on. */
+ }
+
+ if (objspace->flags.dont_incremental ||
+ reason & GPR_FLAG_IMMEDIATE_MARK ||
+ ruby_gc_stressful) {
+ objspace->flags.during_incremental_marking = FALSE;
+ }
+ else {
+ objspace->flags.during_incremental_marking = do_full_mark;
+ }
+
+ /* Explicitly enable compaction (GC.compact) */
+ if (do_full_mark && ruby_enable_autocompact) {
+ objspace->flags.during_compacting = TRUE;
+#if RGENGC_CHECK_MODE
+ objspace->rcompactor.compare_func = ruby_autocompact_compare_func;
+#endif
+ }
+ else {
+ objspace->flags.during_compacting = !!(reason & GPR_FLAG_COMPACT);
+ }
+
+ if (!GC_ENABLE_LAZY_SWEEP || objspace->flags.dont_incremental) {
+ objspace->flags.immediate_sweep = TRUE;
+ }
+
+ if (objspace->flags.immediate_sweep) reason |= GPR_FLAG_IMMEDIATE_SWEEP;
+
+ gc_report(1, objspace, "gc_start(reason: %x) => %u, %d, %d\n",
+ reason,
+ do_full_mark, !is_incremental_marking(objspace), objspace->flags.immediate_sweep);
+
+ RB_DEBUG_COUNTER_INC(gc_count);
+
+ if (reason & GPR_FLAG_MAJOR_MASK) {
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_major_nofree, reason & GPR_FLAG_MAJOR_BY_NOFREE);
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_major_oldgen, reason & GPR_FLAG_MAJOR_BY_OLDGEN);
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_major_shady, reason & GPR_FLAG_MAJOR_BY_SHADY);
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_major_force, reason & GPR_FLAG_MAJOR_BY_FORCE);
+#if RGENGC_ESTIMATE_OLDMALLOC
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_major_oldmalloc, reason & GPR_FLAG_MAJOR_BY_OLDMALLOC);
+#endif
+ }
+ else {
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_minor_newobj, reason & GPR_FLAG_NEWOBJ);
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_minor_malloc, reason & GPR_FLAG_MALLOC);
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_minor_method, reason & GPR_FLAG_METHOD);
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_minor_capi, reason & GPR_FLAG_CAPI);
+ (void)RB_DEBUG_COUNTER_INC_IF(gc_minor_stress, reason & GPR_FLAG_STRESS);
+ }
+
+ objspace->profile.count++;
+ objspace->profile.latest_gc_info = reason;
+ objspace->profile.total_allocated_objects_at_gc_start = total_allocated_objects(objspace);
+ objspace->profile.heap_used_at_gc_start = rb_darray_size(objspace->heap_pages.sorted);
+ objspace->profile.heap_total_slots_at_gc_start = objspace_available_slots(objspace);
+ objspace->profile.weak_references_count = 0;
+ gc_prof_setup_new_record(objspace, reason);
+ gc_reset_malloc_info(objspace, do_full_mark);
+
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_START);
+
+ GC_ASSERT(during_gc);
+
+ gc_prof_timer_start(objspace);
+ {
+ if (gc_marks(objspace, do_full_mark)) {
+ gc_sweep(objspace);
+ }
+ }
+ gc_prof_timer_stop(objspace);
+
+ gc_exit(objspace, gc_enter_event_start, &lock_lev);
+ return TRUE;
+}
+
+static void
+gc_rest(rb_objspace_t *objspace)
+{
+ if (is_incremental_marking(objspace) || is_lazy_sweeping(objspace)) {
+ unsigned int lock_lev;
+ gc_enter(objspace, gc_enter_event_rest, &lock_lev);
+
+ if (RGENGC_CHECK_MODE >= 2) gc_verify_internal_consistency(objspace);
+
+ if (is_incremental_marking(objspace)) {
+ gc_marking_enter(objspace);
+ gc_marks_rest(objspace);
+ gc_marking_exit(objspace);
+
+ gc_sweep(objspace);
+ }
+
+ if (is_lazy_sweeping(objspace)) {
+ gc_sweeping_enter(objspace);
+ gc_sweep_rest(objspace);
+ gc_sweeping_exit(objspace);
+ }
+
+ gc_exit(objspace, gc_enter_event_rest, &lock_lev);
+ }
+}
+
+struct objspace_and_reason {
+ rb_objspace_t *objspace;
+ unsigned int reason;
+};
+
+static void
+gc_current_status_fill(rb_objspace_t *objspace, char *buff)
+{
+ int i = 0;
+ if (is_marking(objspace)) {
+ buff[i++] = 'M';
+ if (is_full_marking(objspace)) buff[i++] = 'F';
+ if (is_incremental_marking(objspace)) buff[i++] = 'I';
+ }
+ else if (is_sweeping(objspace)) {
+ buff[i++] = 'S';
+ if (is_lazy_sweeping(objspace)) buff[i++] = 'L';
+ }
+ else {
+ buff[i++] = 'N';
+ }
+ buff[i] = '\0';
+}
+
+static const char *
+gc_current_status(rb_objspace_t *objspace)
+{
+ static char buff[0x10];
+ gc_current_status_fill(objspace, buff);
+ return buff;
+}
+
+#if PRINT_ENTER_EXIT_TICK
+
+static tick_t last_exit_tick;
+static tick_t enter_tick;
+static int enter_count = 0;
+static char last_gc_status[0x10];
+
+static inline void
+gc_record(rb_objspace_t *objspace, int direction, const char *event)
+{
+ if (direction == 0) { /* enter */
+ enter_count++;
+ enter_tick = tick();
+ gc_current_status_fill(objspace, last_gc_status);
+ }
+ else { /* exit */
+ tick_t exit_tick = tick();
+ char current_gc_status[0x10];
+ gc_current_status_fill(objspace, current_gc_status);
+#if 1
+ /* [last mutator time] [gc time] [event] */
+ fprintf(stderr, "%"PRItick"\t%"PRItick"\t%s\t[%s->%s|%c]\n",
+ enter_tick - last_exit_tick,
+ exit_tick - enter_tick,
+ event,
+ last_gc_status, current_gc_status,
+ (objspace->profile.latest_gc_info & GPR_FLAG_MAJOR_MASK) ? '+' : '-');
+ last_exit_tick = exit_tick;
+#else
+ /* [enter_tick] [gc time] [event] */
+ fprintf(stderr, "%"PRItick"\t%"PRItick"\t%s\t[%s->%s|%c]\n",
+ enter_tick,
+ exit_tick - enter_tick,
+ event,
+ last_gc_status, current_gc_status,
+ (objspace->profile.latest_gc_info & GPR_FLAG_MAJOR_MASK) ? '+' : '-');
+#endif
+ }
+}
+#else /* PRINT_ENTER_EXIT_TICK */
+static inline void
+gc_record(rb_objspace_t *objspace, int direction, const char *event)
+{
+ /* null */
+}
+#endif /* PRINT_ENTER_EXIT_TICK */
+
+static const char *
+gc_enter_event_cstr(enum gc_enter_event event)
+{
+ switch (event) {
+ case gc_enter_event_start: return "start";
+ case gc_enter_event_continue: return "continue";
+ case gc_enter_event_rest: return "rest";
+ case gc_enter_event_finalizer: return "finalizer";
+ }
+ return NULL;
+}
+
+static void
+gc_enter_count(enum gc_enter_event event)
+{
+ switch (event) {
+ case gc_enter_event_start: RB_DEBUG_COUNTER_INC(gc_enter_start); break;
+ case gc_enter_event_continue: RB_DEBUG_COUNTER_INC(gc_enter_continue); break;
+ case gc_enter_event_rest: RB_DEBUG_COUNTER_INC(gc_enter_rest); break;
+ case gc_enter_event_finalizer: RB_DEBUG_COUNTER_INC(gc_enter_finalizer); break;
+ }
+}
+
+static bool current_process_time(struct timespec *ts);
+
+static void
+gc_clock_start(struct timespec *ts)
+{
+ if (!current_process_time(ts)) {
+ ts->tv_sec = 0;
+ ts->tv_nsec = 0;
+ }
+}
+
+static unsigned long long
+gc_clock_end(struct timespec *ts)
+{
+ struct timespec end_time;
+
+ if ((ts->tv_sec > 0 || ts->tv_nsec > 0) &&
+ current_process_time(&end_time) &&
+ end_time.tv_sec >= ts->tv_sec) {
+ return (unsigned long long)(end_time.tv_sec - ts->tv_sec) * (1000 * 1000 * 1000) +
+ (end_time.tv_nsec - ts->tv_nsec);
+ }
+
+ return 0;
+}
+
+static inline void
+gc_enter(rb_objspace_t *objspace, enum gc_enter_event event, unsigned int *lock_lev)
+{
+ *lock_lev = RB_GC_VM_LOCK();
+
+ switch (event) {
+ case gc_enter_event_rest:
+ case gc_enter_event_start:
+ case gc_enter_event_continue:
+ // stop other ractors
+ rb_gc_vm_barrier();
+ break;
+ default:
+ break;
+ }
+
+ gc_enter_count(event);
+ if (RB_UNLIKELY(during_gc != 0)) rb_bug("during_gc != 0");
+ if (RGENGC_CHECK_MODE >= 3) gc_verify_internal_consistency(objspace);
+
+ during_gc = TRUE;
+ RUBY_DEBUG_LOG("%s (%s)",gc_enter_event_cstr(event), gc_current_status(objspace));
+ gc_report(1, objspace, "gc_enter: %s [%s]\n", gc_enter_event_cstr(event), gc_current_status(objspace));
+ gc_record(objspace, 0, gc_enter_event_cstr(event));
+
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_ENTER);
+}
+
+static inline void
+gc_exit(rb_objspace_t *objspace, enum gc_enter_event event, unsigned int *lock_lev)
+{
+ GC_ASSERT(during_gc != 0);
+
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_EXIT);
+
+ gc_record(objspace, 1, gc_enter_event_cstr(event));
+ RUBY_DEBUG_LOG("%s (%s)", gc_enter_event_cstr(event), gc_current_status(objspace));
+ gc_report(1, objspace, "gc_exit: %s [%s]\n", gc_enter_event_cstr(event), gc_current_status(objspace));
+ during_gc = FALSE;
+
+ RB_GC_VM_UNLOCK(*lock_lev);
+}
+
+#ifndef MEASURE_GC
+#define MEASURE_GC (objspace->flags.measure_gc)
+#endif
+
+static void
+gc_marking_enter(rb_objspace_t *objspace)
+{
+ GC_ASSERT(during_gc != 0);
+
+ if (MEASURE_GC) {
+ gc_clock_start(&objspace->profile.marking_start_time);
+ }
+
+ rb_gc_initialize_vm_context(&objspace->vm_context);
+}
+
+static void
+gc_marking_exit(rb_objspace_t *objspace)
+{
+ GC_ASSERT(during_gc != 0);
+
+ if (MEASURE_GC) {
+ objspace->profile.marking_time_ns += gc_clock_end(&objspace->profile.marking_start_time);
+ }
+}
+
+static void
+gc_sweeping_enter(rb_objspace_t *objspace)
+{
+ GC_ASSERT(during_gc != 0);
+
+ if (MEASURE_GC) {
+ gc_clock_start(&objspace->profile.sweeping_start_time);
+ }
+}
+
+static void
+gc_sweeping_exit(rb_objspace_t *objspace)
+{
+ GC_ASSERT(during_gc != 0);
+
+ if (MEASURE_GC) {
+ objspace->profile.sweeping_time_ns += gc_clock_end(&objspace->profile.sweeping_start_time);
+ }
+}
+
+static void *
+gc_with_gvl(void *ptr)
+{
+ struct objspace_and_reason *oar = (struct objspace_and_reason *)ptr;
+ return (void *)(VALUE)garbage_collect(oar->objspace, oar->reason);
+}
+
+int ruby_thread_has_gvl_p(void);
+
+static int
+garbage_collect_with_gvl(rb_objspace_t *objspace, unsigned int reason)
+{
+ if (dont_gc_val()) {
+ return TRUE;
+ }
+ else if (!ruby_native_thread_p()) {
+ return TRUE;
+ }
+ else if (!ruby_thread_has_gvl_p()) {
+ void *ret;
+ struct objspace_and_reason oar;
+ oar.objspace = objspace;
+ oar.reason = reason;
+ ret = rb_thread_call_with_gvl(gc_with_gvl, (void *)&oar);
+
+ return !!ret;
+ }
+ else {
+ return garbage_collect(objspace, reason);
+ }
+}
+
+static int
+gc_set_candidate_object_i(void *vstart, void *vend, size_t stride, void *data)
+{
+ rb_objspace_t *objspace = (rb_objspace_t *)data;
+
+ VALUE v = (VALUE)vstart;
+ for (; v != (VALUE)vend; v += stride) {
+ asan_unpoisoning_object(v) {
+ switch (BUILTIN_TYPE(v)) {
+ case T_NONE:
+ case T_ZOMBIE:
+ break;
+ default:
+ rb_gc_prepare_heap_process_object(v);
+ if (!RVALUE_OLD_P(objspace, v) && !RVALUE_WB_UNPROTECTED(objspace, v)) {
+ RVALUE_AGE_SET_CANDIDATE(objspace, v);
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+void
+rb_gc_impl_start(void *objspace_ptr, bool full_mark, bool immediate_mark, bool immediate_sweep, bool compact)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ unsigned int reason = (GPR_FLAG_FULL_MARK |
+ GPR_FLAG_IMMEDIATE_MARK |
+ GPR_FLAG_IMMEDIATE_SWEEP |
+ GPR_FLAG_METHOD);
+
+ int full_marking_p = gc_config_full_mark_val;
+ gc_config_full_mark_set(TRUE);
+
+ /* For now, compact implies full mark / sweep, so ignore other flags */
+ if (compact) {
+ GC_ASSERT(GC_COMPACTION_SUPPORTED);
+
+ reason |= GPR_FLAG_COMPACT;
+ }
+ else {
+ if (!full_mark) reason &= ~GPR_FLAG_FULL_MARK;
+ if (!immediate_mark) reason &= ~GPR_FLAG_IMMEDIATE_MARK;
+ if (!immediate_sweep) reason &= ~GPR_FLAG_IMMEDIATE_SWEEP;
+ }
+
+ garbage_collect(objspace, reason);
+ gc_finalize_deferred(objspace);
+
+ gc_config_full_mark_set(full_marking_p);
+}
+
+void
+rb_gc_impl_prepare_heap(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ size_t orig_total_slots = objspace_available_slots(objspace);
+ size_t orig_allocatable_bytes = objspace->heap_pages.allocatable_bytes;
+
+ rb_gc_impl_each_objects(objspace, gc_set_candidate_object_i, objspace_ptr);
+
+ double orig_max_free_slots = gc_params.heap_free_slots_max_ratio;
+ /* Ensure that all empty pages are moved onto empty_pages. */
+ gc_params.heap_free_slots_max_ratio = 0.0;
+ rb_gc_impl_start(objspace, true, true, true, true);
+ gc_params.heap_free_slots_max_ratio = orig_max_free_slots;
+
+ objspace->heap_pages.allocatable_bytes = 0;
+ heap_pages_freeable_pages = objspace->empty_pages_count;
+ heap_pages_free_unused_pages(objspace_ptr);
+ GC_ASSERT(heap_pages_freeable_pages == 0);
+ GC_ASSERT(objspace->empty_pages_count == 0);
+ objspace->heap_pages.allocatable_bytes = orig_allocatable_bytes;
+
+ size_t total_slots = objspace_available_slots(objspace);
+ if (orig_total_slots > total_slots) {
+ objspace->heap_pages.allocatable_bytes += (orig_total_slots - total_slots) * heaps[0].slot_size;
+ }
+
+#if defined(HAVE_MALLOC_TRIM) && !defined(RUBY_ALTERNATIVE_MALLOC_HEADER)
+ malloc_trim(0);
+#endif
+}
+
+static int
+gc_is_moveable_obj(rb_objspace_t *objspace, VALUE obj)
+{
+ GC_ASSERT(!SPECIAL_CONST_P(obj));
+
+ switch (BUILTIN_TYPE(obj)) {
+ case T_NONE:
+ case T_MOVED:
+ case T_ZOMBIE:
+ return FALSE;
+ case T_SYMBOL:
+ case T_STRING:
+ case T_OBJECT:
+ case T_FLOAT:
+ case T_IMEMO:
+ case T_ARRAY:
+ case T_BIGNUM:
+ case T_ICLASS:
+ case T_MODULE:
+ case T_REGEXP:
+ case T_DATA:
+ case T_MATCH:
+ case T_STRUCT:
+ case T_HASH:
+ case T_FILE:
+ case T_COMPLEX:
+ case T_RATIONAL:
+ case T_NODE:
+ case T_CLASS:
+ if (FL_TEST_RAW(obj, FL_FINALIZE)) {
+ /* The finalizer table is a numtable. It looks up objects by address.
+ * We can't mark the keys in the finalizer table because that would
+ * prevent the objects from being collected. This check prevents
+ * objects that are keys in the finalizer table from being moved
+ * without directly pinning them. */
+ GC_ASSERT(st_is_member(finalizer_table, obj));
+
+ return FALSE;
+ }
+ GC_ASSERT(RVALUE_MARKED(objspace, obj));
+ GC_ASSERT(!RVALUE_PINNED(objspace, obj));
+
+ return TRUE;
+
+ default:
+ rb_bug("gc_is_moveable_obj: unreachable (%d)", (int)BUILTIN_TYPE(obj));
+ break;
+ }
+
+ return FALSE;
+}
+
+void rb_mv_generic_ivar(VALUE src, VALUE dst);
+
+static VALUE
+gc_move(rb_objspace_t *objspace, VALUE src, VALUE dest, struct heap_page *src_page, struct heap_page *dest_page)
+{
+ size_t src_slot_size = src_page->slot_size;
+ size_t slot_size = dest_page->slot_size;
+
+ int marked;
+ int wb_unprotected;
+ int uncollectible;
+ int age;
+
+ gc_report(4, objspace, "Moving object: %p -> %p\n", (void *)src, (void *)dest);
+
+ GC_ASSERT(BUILTIN_TYPE(src) != T_NONE);
+ GC_ASSERT(!MARKED_IN_BITMAP(GET_HEAP_MARK_BITS(dest), dest));
+
+ GC_ASSERT(!RVALUE_MARKING(objspace, src));
+
+ /* Save off bits for current object. */
+ marked = RVALUE_MARKED(objspace, src);
+ wb_unprotected = RVALUE_WB_UNPROTECTED(objspace, src);
+ uncollectible = RVALUE_UNCOLLECTIBLE(objspace, src);
+ bool remembered = RVALUE_REMEMBERED(objspace, src);
+ age = RVALUE_AGE_GET(src);
+
+ /* Clear bits for eventual T_MOVED */
+ CLEAR_IN_BITMAP(GET_HEAP_MARK_BITS(src), src);
+ CLEAR_IN_BITMAP(GET_HEAP_WB_UNPROTECTED_BITS(src), src);
+ CLEAR_IN_BITMAP(GET_HEAP_UNCOLLECTIBLE_BITS(src), src);
+ CLEAR_IN_BITMAP(GET_HEAP_PAGE(src)->remembered_bits, src);
+
+ /* Move the object */
+ memcpy((void *)dest, (void *)src, MIN(src_slot_size, slot_size));
+
+ if (src_slot_size != slot_size && RB_TYPE_P(src, T_OBJECT)) {
+ rb_gc_obj_changed_pool(dest, dest_page->heap - heaps);
+ }
+
+ if (RVALUE_OVERHEAD > 0) {
+ void *dest_overhead = (void *)(((uintptr_t)dest) + slot_size - RVALUE_OVERHEAD);
+ void *src_overhead = (void *)(((uintptr_t)src) + src_slot_size - RVALUE_OVERHEAD);
+
+ memcpy(dest_overhead, src_overhead, RVALUE_OVERHEAD);
+ }
+
+ memset((void *)src, 0, src_slot_size);
+ RVALUE_AGE_SET_BITMAP(src, 0);
+
+ /* Set bits for object in new location */
+ if (remembered) {
+ MARK_IN_BITMAP(GET_HEAP_PAGE(dest)->remembered_bits, dest);
+ }
+ else {
+ CLEAR_IN_BITMAP(GET_HEAP_PAGE(dest)->remembered_bits, dest);
+ }
+
+ if (marked) {
+ MARK_IN_BITMAP(GET_HEAP_MARK_BITS(dest), dest);
+ }
+ else {
+ CLEAR_IN_BITMAP(GET_HEAP_MARK_BITS(dest), dest);
+ }
+
+ if (wb_unprotected) {
+ MARK_IN_BITMAP(GET_HEAP_WB_UNPROTECTED_BITS(dest), dest);
+ }
+ else {
+ CLEAR_IN_BITMAP(GET_HEAP_WB_UNPROTECTED_BITS(dest), dest);
+ }
+
+ if (uncollectible) {
+ MARK_IN_BITMAP(GET_HEAP_UNCOLLECTIBLE_BITS(dest), dest);
+ }
+ else {
+ CLEAR_IN_BITMAP(GET_HEAP_UNCOLLECTIBLE_BITS(dest), dest);
+ }
+
+ RVALUE_AGE_SET(dest, age);
+ /* Assign forwarding address */
+ RMOVED(src)->flags = T_MOVED;
+ RMOVED(src)->dummy = Qundef;
+ RMOVED(src)->destination = dest;
+ GC_ASSERT(BUILTIN_TYPE(dest) != T_NONE);
+
+ GET_HEAP_PAGE(src)->heap->total_freed_objects++;
+ GET_HEAP_PAGE(dest)->heap->total_allocated_objects++;
+
+ return src;
+}
+
+#if GC_CAN_COMPILE_COMPACTION
+static int
+compare_pinned_slots(const void *left, const void *right, void *dummy)
+{
+ struct heap_page *left_page;
+ struct heap_page *right_page;
+
+ left_page = *(struct heap_page * const *)left;
+ right_page = *(struct heap_page * const *)right;
+
+ return left_page->pinned_slots - right_page->pinned_slots;
+}
+
+static int
+compare_free_slots(const void *left, const void *right, void *dummy)
+{
+ struct heap_page *left_page;
+ struct heap_page *right_page;
+
+ left_page = *(struct heap_page * const *)left;
+ right_page = *(struct heap_page * const *)right;
+
+ return left_page->free_slots - right_page->free_slots;
+}
+
+static void
+gc_sort_heap_by_compare_func(rb_objspace_t *objspace, gc_compact_compare_func compare_func)
+{
+ for (int j = 0; j < HEAP_COUNT; j++) {
+ rb_heap_t *heap = &heaps[j];
+
+ size_t total_pages = heap->total_pages;
+ size_t size = rb_size_mul_or_raise(total_pages, sizeof(struct heap_page *), rb_eRuntimeError);
+ struct heap_page *page = 0, **page_list = malloc(size);
+ size_t i = 0;
+
+ heap->free_pages = NULL;
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ page_list[i++] = page;
+ GC_ASSERT(page);
+ }
+
+ GC_ASSERT((size_t)i == total_pages);
+
+ /* Sort the heap so "filled pages" are first. `heap_add_page` adds to the
+ * head of the list, so empty pages will end up at the start of the heap */
+ ruby_qsort(page_list, total_pages, sizeof(struct heap_page *), compare_func, NULL);
+
+ /* Reset the eden heap */
+ ccan_list_head_init(&heap->pages);
+
+ for (i = 0; i < total_pages; i++) {
+ ccan_list_add(&heap->pages, &page_list[i]->page_node);
+ if (page_list[i]->free_slots != 0) {
+ heap_add_freepage(heap, page_list[i]);
+ }
+ }
+
+ free(page_list);
+ }
+}
+#endif
+
+void
+rb_gc_impl_register_pinning_obj(void *objspace_ptr, VALUE obj)
+{
+ /* no-op */
+}
+
+bool
+rb_gc_impl_object_moved_p(void *objspace_ptr, VALUE obj)
+{
+ return gc_object_moved_p(objspace_ptr, obj);
+}
+
+static int
+gc_ref_update(void *vstart, void *vend, size_t stride, rb_objspace_t *objspace, struct heap_page *page)
+{
+ VALUE v = (VALUE)vstart;
+
+ page->flags.has_uncollectible_wb_unprotected_objects = FALSE;
+ page->flags.has_remembered_objects = FALSE;
+
+ /* For each object on the page */
+ for (; v != (VALUE)vend; v += stride) {
+ asan_unpoisoning_object(v) {
+ switch (BUILTIN_TYPE(v)) {
+ case T_NONE:
+ case T_MOVED:
+ case T_ZOMBIE:
+ break;
+ default:
+ if (RVALUE_WB_UNPROTECTED(objspace, v)) {
+ page->flags.has_uncollectible_wb_unprotected_objects = TRUE;
+ }
+ if (RVALUE_REMEMBERED(objspace, v)) {
+ page->flags.has_remembered_objects = TRUE;
+ }
+ if (page->flags.before_sweep) {
+ if (RVALUE_MARKED(objspace, v)) {
+ rb_gc_update_object_references(objspace, v);
+ }
+ }
+ else {
+ rb_gc_update_object_references(objspace, v);
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int
+gc_update_references_weak_table_i(VALUE obj, void *data)
+{
+ int ret;
+ asan_unpoisoning_object(obj) {
+ ret = BUILTIN_TYPE(obj) == T_MOVED ? ST_REPLACE : ST_CONTINUE;
+ }
+ return ret;
+}
+
+static int
+gc_update_references_weak_table_replace_i(VALUE *obj, void *data)
+{
+ *obj = rb_gc_location(*obj);
+
+ return ST_CONTINUE;
+}
+
+static void
+gc_update_references(rb_objspace_t *objspace)
+{
+ objspace->flags.during_reference_updating = true;
+
+ rb_gc_before_updating_jit_code();
+
+ struct heap_page *page = NULL;
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ bool should_set_mark_bits = TRUE;
+ rb_heap_t *heap = &heaps[i];
+
+ ccan_list_for_each(&heap->pages, page, page_node) {
+ uintptr_t start = (uintptr_t)page->start;
+ uintptr_t end = start + (page->total_slots * heap->slot_size);
+
+ gc_ref_update((void *)start, (void *)end, heap->slot_size, objspace, page);
+ if (page == heap->sweeping_page) {
+ should_set_mark_bits = FALSE;
+ }
+ if (should_set_mark_bits) {
+ gc_setup_mark_bits(page);
+ }
+ }
+ }
+
+ gc_update_table_refs(finalizer_table);
+
+ rb_gc_update_vm_references((void *)objspace);
+
+ for (int table = 0; table < RB_GC_VM_WEAK_TABLE_COUNT; table++) {
+ rb_gc_vm_weak_table_foreach(
+ gc_update_references_weak_table_i,
+ gc_update_references_weak_table_replace_i,
+ NULL,
+ false,
+ table
+ );
+ }
+
+ rb_gc_after_updating_jit_code();
+
+ objspace->flags.during_reference_updating = false;
+}
+
+#if GC_CAN_COMPILE_COMPACTION
+static void
+root_obj_check_moved_i(const char *category, VALUE obj, void *data)
+{
+ rb_objspace_t *objspace = data;
+
+ if (gc_object_moved_p(objspace, obj)) {
+ rb_bug("ROOT %s points to MOVED: %p -> %s", category, (void *)obj, rb_obj_info(rb_gc_impl_location(objspace, obj)));
+ }
+}
+
+static void
+reachable_object_check_moved_i(VALUE ref, void *data)
+{
+ VALUE parent = (VALUE)data;
+ if (gc_object_moved_p(rb_gc_get_objspace(), ref)) {
+ rb_bug("Object %s points to MOVED: %p -> %s", rb_obj_info(parent), (void *)ref, rb_obj_info(rb_gc_impl_location(rb_gc_get_objspace(), ref)));
+ }
+}
+
+static int
+heap_check_moved_i(void *vstart, void *vend, size_t stride, void *data)
+{
+ rb_objspace_t *objspace = data;
+
+ VALUE v = (VALUE)vstart;
+ for (; v != (VALUE)vend; v += stride) {
+ if (gc_object_moved_p(objspace, v)) {
+ /* Moved object still on the heap, something may have a reference. */
+ }
+ else {
+ asan_unpoisoning_object(v) {
+ switch (BUILTIN_TYPE(v)) {
+ case T_NONE:
+ case T_ZOMBIE:
+ break;
+ default:
+ if (!rb_gc_impl_garbage_object_p(objspace, v)) {
+ rb_objspace_reachable_objects_from(v, reachable_object_check_moved_i, (void *)v);
+ }
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+#endif
+
+bool
+rb_gc_impl_during_gc_p(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ return during_gc;
+}
+
+#if RGENGC_PROFILE >= 2
+
+static const char*
+type_name(int type, VALUE obj)
+{
+ switch ((enum ruby_value_type)type) {
+ case RUBY_T_NONE: return "T_NONE";
+ case RUBY_T_OBJECT: return "T_OBJECT";
+ case RUBY_T_CLASS: return "T_CLASS";
+ case RUBY_T_MODULE: return "T_MODULE";
+ case RUBY_T_FLOAT: return "T_FLOAT";
+ case RUBY_T_STRING: return "T_STRING";
+ case RUBY_T_REGEXP: return "T_REGEXP";
+ case RUBY_T_ARRAY: return "T_ARRAY";
+ case RUBY_T_HASH: return "T_HASH";
+ case RUBY_T_STRUCT: return "T_STRUCT";
+ case RUBY_T_BIGNUM: return "T_BIGNUM";
+ case RUBY_T_FILE: return "T_FILE";
+ case RUBY_T_DATA: return "T_DATA";
+ case RUBY_T_MATCH: return "T_MATCH";
+ case RUBY_T_COMPLEX: return "T_COMPLEX";
+ case RUBY_T_RATIONAL: return "T_RATIONAL";
+ case RUBY_T_NIL: return "T_NIL";
+ case RUBY_T_TRUE: return "T_TRUE";
+ case RUBY_T_FALSE: return "T_FALSE";
+ case RUBY_T_SYMBOL: return "T_SYMBOL";
+ case RUBY_T_FIXNUM: return "T_FIXNUM";
+ case RUBY_T_UNDEF: return "T_UNDEF";
+ case RUBY_T_IMEMO: return "T_IMEMO";
+ case RUBY_T_NODE: return "T_NODE";
+ case RUBY_T_ICLASS: return "T_ICLASS";
+ case RUBY_T_ZOMBIE: return "T_ZOMBIE";
+ case RUBY_T_MOVED: return "T_MOVED";
+ default: return "unknown";
+ }
+}
+
+static void
+gc_count_add_each_types(VALUE hash, const char *name, const size_t *types)
+{
+ VALUE result = rb_hash_new_with_size(T_MASK);
+ int i;
+ for (i=0; i<T_MASK; i++) {
+ const char *type = type_name(i, 0);
+ rb_hash_aset(result, ID2SYM(rb_intern(type)), SIZET2NUM(types[i]));
+ }
+ rb_hash_aset(hash, ID2SYM(rb_intern(name)), result);
+}
+#endif
+
+size_t
+rb_gc_impl_gc_count(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ return objspace->profile.count;
+}
+
+static VALUE
+gc_info_decode(rb_objspace_t *objspace, const VALUE hash_or_key, const unsigned int orig_flags)
+{
+ static VALUE sym_major_by = Qnil, sym_gc_by, sym_immediate_sweep, sym_have_finalizer, sym_state, sym_need_major_by;
+ static VALUE sym_nofree, sym_oldgen, sym_shady, sym_force, sym_stress;
+#if RGENGC_ESTIMATE_OLDMALLOC
+ static VALUE sym_oldmalloc;
+#endif
+ static VALUE sym_newobj, sym_malloc, sym_method, sym_capi;
+ static VALUE sym_none, sym_marking, sym_sweeping;
+ static VALUE sym_weak_references_count;
+ VALUE hash = Qnil, key = Qnil;
+ VALUE major_by, need_major_by;
+ unsigned int flags = orig_flags ? orig_flags : objspace->profile.latest_gc_info;
+
+ if (SYMBOL_P(hash_or_key)) {
+ key = hash_or_key;
+ }
+ else if (RB_TYPE_P(hash_or_key, T_HASH)) {
+ hash = hash_or_key;
+ }
+ else {
+ rb_bug("gc_info_decode: non-hash or symbol given");
+ }
+
+ if (NIL_P(sym_major_by)) {
+#define S(s) sym_##s = ID2SYM(rb_intern_const(#s))
+ S(major_by);
+ S(gc_by);
+ S(immediate_sweep);
+ S(have_finalizer);
+ S(state);
+ S(need_major_by);
+
+ S(stress);
+ S(nofree);
+ S(oldgen);
+ S(shady);
+ S(force);
+#if RGENGC_ESTIMATE_OLDMALLOC
+ S(oldmalloc);
+#endif
+ S(newobj);
+ S(malloc);
+ S(method);
+ S(capi);
+
+ S(none);
+ S(marking);
+ S(sweeping);
+
+ S(weak_references_count);
+#undef S
+ }
+
+#define SET(name, attr) \
+ if (key == sym_##name) \
+ return (attr); \
+ else if (hash != Qnil) \
+ rb_hash_aset(hash, sym_##name, (attr));
+
+ major_by =
+ (flags & GPR_FLAG_MAJOR_BY_NOFREE) ? sym_nofree :
+ (flags & GPR_FLAG_MAJOR_BY_OLDGEN) ? sym_oldgen :
+ (flags & GPR_FLAG_MAJOR_BY_SHADY) ? sym_shady :
+ (flags & GPR_FLAG_MAJOR_BY_FORCE) ? sym_force :
+#if RGENGC_ESTIMATE_OLDMALLOC
+ (flags & GPR_FLAG_MAJOR_BY_OLDMALLOC) ? sym_oldmalloc :
+#endif
+ Qnil;
+ SET(major_by, major_by);
+
+ if (orig_flags == 0) { /* set need_major_by only if flags not set explicitly */
+ unsigned int need_major_flags = gc_needs_major_flags;
+ need_major_by =
+ (need_major_flags & GPR_FLAG_MAJOR_BY_NOFREE) ? sym_nofree :
+ (need_major_flags & GPR_FLAG_MAJOR_BY_OLDGEN) ? sym_oldgen :
+ (need_major_flags & GPR_FLAG_MAJOR_BY_SHADY) ? sym_shady :
+ (need_major_flags & GPR_FLAG_MAJOR_BY_FORCE) ? sym_force :
+#if RGENGC_ESTIMATE_OLDMALLOC
+ (need_major_flags & GPR_FLAG_MAJOR_BY_OLDMALLOC) ? sym_oldmalloc :
+#endif
+ Qnil;
+ SET(need_major_by, need_major_by);
+ }
+
+ SET(gc_by,
+ (flags & GPR_FLAG_NEWOBJ) ? sym_newobj :
+ (flags & GPR_FLAG_MALLOC) ? sym_malloc :
+ (flags & GPR_FLAG_METHOD) ? sym_method :
+ (flags & GPR_FLAG_CAPI) ? sym_capi :
+ (flags & GPR_FLAG_STRESS) ? sym_stress :
+ Qnil
+ );
+
+ SET(have_finalizer, (flags & GPR_FLAG_HAVE_FINALIZE) ? Qtrue : Qfalse);
+ SET(immediate_sweep, (flags & GPR_FLAG_IMMEDIATE_SWEEP) ? Qtrue : Qfalse);
+
+ if (orig_flags == 0) {
+ SET(state, gc_mode(objspace) == gc_mode_none ? sym_none :
+ gc_mode(objspace) == gc_mode_marking ? sym_marking : sym_sweeping);
+ }
+
+ SET(weak_references_count, LONG2FIX(objspace->profile.weak_references_count));
+#undef SET
+
+ if (!NIL_P(key)) {
+ // Matched key should return above
+ return Qundef;
+ }
+
+ return hash;
+}
+
+VALUE
+rb_gc_impl_latest_gc_info(void *objspace_ptr, VALUE key)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ return gc_info_decode(objspace, key, 0);
+}
+
+
+enum gc_stat_sym {
+ gc_stat_sym_count,
+ gc_stat_sym_time,
+ gc_stat_sym_marking_time,
+ gc_stat_sym_sweeping_time,
+ gc_stat_sym_heap_allocated_pages,
+ gc_stat_sym_heap_empty_pages,
+ gc_stat_sym_heap_allocatable_bytes,
+ gc_stat_sym_heap_available_slots,
+ gc_stat_sym_heap_live_slots,
+ gc_stat_sym_heap_free_slots,
+ gc_stat_sym_heap_final_slots,
+ gc_stat_sym_heap_marked_slots,
+ gc_stat_sym_heap_eden_pages,
+ gc_stat_sym_total_allocated_pages,
+ gc_stat_sym_total_freed_pages,
+ gc_stat_sym_total_allocated_objects,
+ gc_stat_sym_total_freed_objects,
+ gc_stat_sym_total_malloc_bytes,
+ gc_stat_sym_total_free_bytes,
+ gc_stat_sym_malloc_increase_bytes,
+ gc_stat_sym_malloc_increase_bytes_limit,
+ gc_stat_sym_minor_gc_count,
+ gc_stat_sym_major_gc_count,
+ gc_stat_sym_compact_count,
+ gc_stat_sym_read_barrier_faults,
+ gc_stat_sym_total_moved_objects,
+ gc_stat_sym_remembered_wb_unprotected_objects,
+ gc_stat_sym_remembered_wb_unprotected_objects_limit,
+ gc_stat_sym_old_objects,
+ gc_stat_sym_old_objects_limit,
+#if RGENGC_ESTIMATE_OLDMALLOC
+ gc_stat_sym_oldmalloc_increase_bytes,
+ gc_stat_sym_oldmalloc_increase_bytes_limit,
+#endif
+#if RGENGC_PROFILE
+ gc_stat_sym_total_generated_normal_object_count,
+ gc_stat_sym_total_generated_shady_object_count,
+ gc_stat_sym_total_shade_operation_count,
+ gc_stat_sym_total_promoted_count,
+ gc_stat_sym_total_remembered_normal_object_count,
+ gc_stat_sym_total_remembered_shady_object_count,
+#endif
+ gc_stat_sym_last
+};
+
+static VALUE gc_stat_symbols[gc_stat_sym_last];
+
+static void
+setup_gc_stat_symbols(void)
+{
+ if (gc_stat_symbols[0] == 0) {
+#define S(s) gc_stat_symbols[gc_stat_sym_##s] = ID2SYM(rb_intern_const(#s))
+ S(count);
+ S(time);
+ S(marking_time),
+ S(sweeping_time),
+ S(heap_allocated_pages);
+ S(heap_empty_pages);
+ S(heap_allocatable_bytes);
+ S(heap_available_slots);
+ S(heap_live_slots);
+ S(heap_free_slots);
+ S(heap_final_slots);
+ S(heap_marked_slots);
+ S(heap_eden_pages);
+ S(total_allocated_pages);
+ S(total_freed_pages);
+ S(total_allocated_objects);
+ S(total_freed_objects);
+ S(total_malloc_bytes);
+ S(total_free_bytes);
+ S(malloc_increase_bytes);
+ S(malloc_increase_bytes_limit);
+ S(minor_gc_count);
+ S(major_gc_count);
+ S(compact_count);
+ S(read_barrier_faults);
+ S(total_moved_objects);
+ S(remembered_wb_unprotected_objects);
+ S(remembered_wb_unprotected_objects_limit);
+ S(old_objects);
+ S(old_objects_limit);
+#if RGENGC_ESTIMATE_OLDMALLOC
+ S(oldmalloc_increase_bytes);
+ S(oldmalloc_increase_bytes_limit);
+#endif
+#if RGENGC_PROFILE
+ S(total_generated_normal_object_count);
+ S(total_generated_shady_object_count);
+ S(total_shade_operation_count);
+ S(total_promoted_count);
+ S(total_remembered_normal_object_count);
+ S(total_remembered_shady_object_count);
+#endif /* RGENGC_PROFILE */
+#undef S
+ }
+}
+
+static uint64_t
+ns_to_ms(uint64_t ns)
+{
+ return ns / (1000 * 1000);
+}
+
+static void malloc_increase_local_flush(rb_objspace_t *objspace);
+
+VALUE
+rb_gc_impl_stat(void *objspace_ptr, VALUE hash_or_sym)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ VALUE hash = Qnil, key = Qnil;
+
+ setup_gc_stat_symbols();
+
+ ractor_cache_flush_count(objspace, rb_gc_get_ractor_newobj_cache());
+ malloc_increase_local_flush(objspace);
+
+ if (RB_TYPE_P(hash_or_sym, T_HASH)) {
+ hash = hash_or_sym;
+ }
+ else if (SYMBOL_P(hash_or_sym)) {
+ key = hash_or_sym;
+ }
+ else {
+ rb_bug("non-hash or symbol given");
+ }
+
+#define SET(name, attr) \
+ if (key == gc_stat_symbols[gc_stat_sym_##name]) \
+ return SIZET2NUM(attr); \
+ else if (hash != Qnil) \
+ rb_hash_aset(hash, gc_stat_symbols[gc_stat_sym_##name], SIZET2NUM(attr));
+#define SET64(name, attr) \
+ if (key == gc_stat_symbols[gc_stat_sym_##name]) \
+ return ULL2NUM(attr); \
+ else if (hash != Qnil) \
+ rb_hash_aset(hash, gc_stat_symbols[gc_stat_sym_##name], ULL2NUM(attr));
+
+ SET(count, objspace->profile.count);
+ SET(time, (size_t)ns_to_ms(objspace->profile.marking_time_ns + objspace->profile.sweeping_time_ns)); // TODO: UINT64T2NUM
+ SET(marking_time, (size_t)ns_to_ms(objspace->profile.marking_time_ns));
+ SET(sweeping_time, (size_t)ns_to_ms(objspace->profile.sweeping_time_ns));
+
+ {
+ uint64_t total_malloc = (uint64_t)gc_counter_load_relaxed(&objspace->malloc_counters.counters.malloc);
+ uint64_t total_free = (uint64_t)gc_counter_load_relaxed(&objspace->malloc_counters.counters.free);
+ SET64(total_malloc_bytes, total_malloc);
+ SET64(total_free_bytes, total_free);
+ }
+
+ /* implementation dependent counters (small / fixnum-safe) */
+ SET(heap_allocated_pages, rb_darray_size(objspace->heap_pages.sorted));
+ SET(heap_empty_pages, objspace->empty_pages_count)
+ SET(heap_allocatable_bytes, objspace->heap_pages.allocatable_bytes);
+ SET(heap_eden_pages, heap_eden_total_pages(objspace));
+ SET(total_allocated_pages, objspace->heap_pages.allocated_pages);
+ SET(total_freed_pages, objspace->heap_pages.freed_pages);
+ SET(malloc_increase_bytes, gc_malloc_counters_increase_unsigned(objspace, &objspace->malloc_counters.counters));
+ SET(malloc_increase_bytes_limit, malloc_limit);
+ SET(minor_gc_count, objspace->profile.minor_gc_count);
+ SET(major_gc_count, objspace->profile.major_gc_count);
+ SET(compact_count, objspace->profile.compact_count);
+ SET(read_barrier_faults, objspace->profile.read_barrier_faults);
+ SET(total_moved_objects, objspace->rcompactor.total_moved);
+ SET(remembered_wb_unprotected_objects, objspace->rgengc.uncollectible_wb_unprotected_objects);
+ SET(remembered_wb_unprotected_objects_limit, objspace->rgengc.uncollectible_wb_unprotected_objects_limit);
+ SET(old_objects, objspace->rgengc.old_objects);
+ SET(old_objects_limit, objspace->rgengc.old_objects_limit);
+#if RGENGC_ESTIMATE_OLDMALLOC
+ SET(oldmalloc_increase_bytes, gc_malloc_counters_increase_unsigned(objspace, &objspace->malloc_counters.oldcounters));
+ SET(oldmalloc_increase_bytes_limit, objspace->rgengc.oldmalloc_increase_limit);
+#endif
+
+ ractor_cache_flush_count(objspace, rb_gc_get_ractor_newobj_cache());
+ SET(total_allocated_objects, total_allocated_objects(objspace));
+ SET(total_freed_objects, total_freed_objects(objspace));
+ SET(heap_available_slots, objspace_available_slots(objspace));
+ SET(heap_live_slots, objspace_live_slots(objspace));
+ SET(heap_free_slots, objspace_free_slots(objspace));
+ SET(heap_final_slots, total_final_slots_count(objspace));
+ SET(heap_marked_slots, objspace->marked_slots);
+
+#if RGENGC_PROFILE
+ SET(total_generated_normal_object_count, objspace->profile.total_generated_normal_object_count);
+ SET(total_generated_shady_object_count, objspace->profile.total_generated_shady_object_count);
+ SET(total_shade_operation_count, objspace->profile.total_shade_operation_count);
+ SET(total_promoted_count, objspace->profile.total_promoted_count);
+ SET(total_remembered_normal_object_count, objspace->profile.total_remembered_normal_object_count);
+ SET(total_remembered_shady_object_count, objspace->profile.total_remembered_shady_object_count);
+#endif /* RGENGC_PROFILE */
+#undef SET
+#undef SET64
+
+ if (!NIL_P(key)) {
+ // Matched key should return above
+ return Qundef;
+ }
+
+#if defined(RGENGC_PROFILE) && RGENGC_PROFILE >= 2
+ if (hash != Qnil) {
+ gc_count_add_each_types(hash, "generated_normal_object_count_types", objspace->profile.generated_normal_object_count_types);
+ gc_count_add_each_types(hash, "generated_shady_object_count_types", objspace->profile.generated_shady_object_count_types);
+ gc_count_add_each_types(hash, "shade_operation_count_types", objspace->profile.shade_operation_count_types);
+ gc_count_add_each_types(hash, "promoted_types", objspace->profile.promoted_types);
+ gc_count_add_each_types(hash, "remembered_normal_object_count_types", objspace->profile.remembered_normal_object_count_types);
+ gc_count_add_each_types(hash, "remembered_shady_object_count_types", objspace->profile.remembered_shady_object_count_types);
+ }
+#endif
+
+ return hash;
+}
+
+enum gc_stat_heap_sym {
+ gc_stat_heap_sym_slot_size,
+ gc_stat_heap_sym_heap_live_slots,
+ gc_stat_heap_sym_heap_free_slots,
+ gc_stat_heap_sym_heap_final_slots,
+ gc_stat_heap_sym_heap_eden_pages,
+ gc_stat_heap_sym_heap_eden_slots,
+ gc_stat_heap_sym_total_allocated_pages,
+ gc_stat_heap_sym_force_major_gc_count,
+ gc_stat_heap_sym_force_incremental_marking_finish_count,
+ gc_stat_heap_sym_heap_allocatable_slots,
+ gc_stat_heap_sym_total_allocated_objects,
+ gc_stat_heap_sym_total_freed_objects,
+ gc_stat_heap_sym_last
+};
+
+static VALUE gc_stat_heap_symbols[gc_stat_heap_sym_last];
+
+static void
+setup_gc_stat_heap_symbols(void)
+{
+ if (gc_stat_heap_symbols[0] == 0) {
+#define S(s) gc_stat_heap_symbols[gc_stat_heap_sym_##s] = ID2SYM(rb_intern_const(#s))
+ S(slot_size);
+ S(heap_live_slots);
+ S(heap_free_slots);
+ S(heap_final_slots);
+ S(heap_eden_pages);
+ S(heap_eden_slots);
+ S(heap_allocatable_slots);
+ S(total_allocated_pages);
+ S(force_major_gc_count);
+ S(force_incremental_marking_finish_count);
+ S(total_allocated_objects);
+ S(total_freed_objects);
+#undef S
+ }
+}
+
+static VALUE
+stat_one_heap(rb_objspace_t *objspace, rb_heap_t *heap, VALUE hash, VALUE key)
+{
+#define SET(name, attr) \
+ if (key == gc_stat_heap_symbols[gc_stat_heap_sym_##name]) \
+ return SIZET2NUM(attr); \
+ else if (hash != Qnil) \
+ rb_hash_aset(hash, gc_stat_heap_symbols[gc_stat_heap_sym_##name], SIZET2NUM(attr));
+
+ SET(slot_size, heap->slot_size);
+ SET(heap_live_slots, heap->total_allocated_objects - heap->total_freed_objects - heap->final_slots_count);
+ SET(heap_free_slots, heap->total_slots - (heap->total_allocated_objects - heap->total_freed_objects));
+ SET(heap_final_slots, heap->final_slots_count);
+ SET(heap_eden_pages, heap->total_pages);
+ SET(heap_eden_slots, heap->total_slots);
+ SET(heap_allocatable_slots, objspace->heap_pages.allocatable_bytes / heap->slot_size);
+ SET(total_allocated_pages, heap->total_allocated_pages);
+ SET(force_major_gc_count, heap->force_major_gc_count);
+ SET(force_incremental_marking_finish_count, heap->force_incremental_marking_finish_count);
+ SET(total_allocated_objects, heap->total_allocated_objects);
+ SET(total_freed_objects, heap->total_freed_objects);
+#undef SET
+
+ if (!NIL_P(key)) {
+ // Matched key should return above
+ return Qundef;
+ }
+
+ return hash;
+}
+
+VALUE
+rb_gc_impl_stat_heap(void *objspace_ptr, VALUE heap_name, VALUE hash_or_sym)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ ractor_cache_flush_count(objspace, rb_gc_get_ractor_newobj_cache());
+
+ setup_gc_stat_heap_symbols();
+
+ if (NIL_P(heap_name)) {
+ if (!RB_TYPE_P(hash_or_sym, T_HASH)) {
+ rb_bug("non-hash given");
+ }
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ VALUE hash = rb_hash_aref(hash_or_sym, INT2FIX(i));
+ if (NIL_P(hash)) {
+ hash = rb_hash_new();
+ rb_hash_aset(hash_or_sym, INT2FIX(i), hash);
+ }
+
+ stat_one_heap(objspace, &heaps[i], hash, Qnil);
+ }
+ }
+ else if (FIXNUM_P(heap_name)) {
+ int heap_idx = FIX2INT(heap_name);
+
+ if (heap_idx < 0 || heap_idx >= HEAP_COUNT) {
+ rb_raise(rb_eArgError, "size pool index out of range");
+ }
+
+ if (SYMBOL_P(hash_or_sym)) {
+ return stat_one_heap(objspace, &heaps[heap_idx], Qnil, hash_or_sym);
+ }
+ else if (RB_TYPE_P(hash_or_sym, T_HASH)) {
+ return stat_one_heap(objspace, &heaps[heap_idx], hash_or_sym, Qnil);
+ }
+ else {
+ rb_bug("non-hash or symbol given");
+ }
+ }
+ else {
+ rb_bug("heap_name must be nil or an Integer");
+ }
+
+ return hash_or_sym;
+}
+
+/* I could include internal.h for this, but doing so undefines some Array macros
+ * necessary for initialising objects, and I don't want to include all the array
+ * headers to get them back
+ * TODO: Investigate why RARRAY_AREF gets undefined in internal.h
+ */
+#ifndef RBOOL
+#define RBOOL(v) (v ? Qtrue : Qfalse)
+#endif
+
+VALUE
+rb_gc_impl_config_get(void *objspace_ptr)
+{
+#define sym(name) ID2SYM(rb_intern_const(name))
+ rb_objspace_t *objspace = objspace_ptr;
+ VALUE hash = rb_hash_new();
+
+ rb_hash_aset(hash, sym("rgengc_allow_full_mark"), RBOOL(gc_config_full_mark_val));
+
+ return hash;
+}
+
+static int
+gc_config_set_key(VALUE key, VALUE value, VALUE data)
+{
+ rb_objspace_t *objspace = (rb_objspace_t *)data;
+ if (rb_sym2id(key) == rb_intern("rgengc_allow_full_mark")) {
+ gc_rest(objspace);
+ gc_config_full_mark_set(RTEST(value));
+ }
+ return ST_CONTINUE;
+}
+
+void
+rb_gc_impl_config_set(void *objspace_ptr, VALUE hash)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (!RB_TYPE_P(hash, T_HASH)) {
+ rb_raise(rb_eArgError, "expected keyword arguments");
+ }
+
+ rb_hash_foreach(hash, gc_config_set_key, (st_data_t)objspace);
+}
+
+VALUE
+rb_gc_impl_stress_get(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ return ruby_gc_stress_mode;
+}
+
+void
+rb_gc_impl_stress_set(void *objspace_ptr, VALUE flag)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ objspace->flags.gc_stressful = RTEST(flag);
+ objspace->gc_stress_mode = flag;
+}
+
+static int
+get_envparam_size(const char *name, size_t *default_value, size_t lower_bound)
+{
+ const char *ptr = getenv(name);
+ ssize_t val;
+
+ if (ptr != NULL && *ptr) {
+ size_t unit = 0;
+ char *end;
+#if SIZEOF_SIZE_T == SIZEOF_LONG_LONG
+ val = strtoll(ptr, &end, 0);
+#else
+ val = strtol(ptr, &end, 0);
+#endif
+ switch (*end) {
+ case 'k': case 'K':
+ unit = 1024;
+ ++end;
+ break;
+ case 'm': case 'M':
+ unit = 1024*1024;
+ ++end;
+ break;
+ case 'g': case 'G':
+ unit = 1024*1024*1024;
+ ++end;
+ break;
+ }
+ while (*end && isspace((unsigned char)*end)) end++;
+ if (*end) {
+ if (RTEST(ruby_verbose)) fprintf(stderr, "invalid string for %s: %s\n", name, ptr);
+ return 0;
+ }
+ if (unit > 0) {
+ if (val < -(ssize_t)(SIZE_MAX / 2 / unit) || (ssize_t)(SIZE_MAX / 2 / unit) < val) {
+ if (RTEST(ruby_verbose)) fprintf(stderr, "%s=%s is ignored because it overflows\n", name, ptr);
+ return 0;
+ }
+ val *= unit;
+ }
+ if (val > 0 && (size_t)val > lower_bound) {
+ if (RTEST(ruby_verbose)) {
+ fprintf(stderr, "%s=%"PRIdSIZE" (default value: %"PRIuSIZE")\n", name, val, *default_value);
+ }
+ *default_value = (size_t)val;
+ return 1;
+ }
+ else {
+ if (RTEST(ruby_verbose)) {
+ fprintf(stderr, "%s=%"PRIdSIZE" (default value: %"PRIuSIZE") is ignored because it must be greater than %"PRIuSIZE".\n",
+ name, val, *default_value, lower_bound);
+ }
+ return 0;
+ }
+ }
+ return 0;
+}
+
+static int
+get_envparam_double(const char *name, double *default_value, double lower_bound, double upper_bound, int accept_zero)
+{
+ const char *ptr = getenv(name);
+ double val;
+
+ if (ptr != NULL && *ptr) {
+ char *end;
+ val = strtod(ptr, &end);
+ if (!*ptr || *end) {
+ if (RTEST(ruby_verbose)) fprintf(stderr, "invalid string for %s: %s\n", name, ptr);
+ return 0;
+ }
+
+ if (accept_zero && val == 0.0) {
+ goto accept;
+ }
+ else if (val <= lower_bound) {
+ if (RTEST(ruby_verbose)) {
+ fprintf(stderr, "%s=%f (default value: %f) is ignored because it must be greater than %f.\n",
+ name, val, *default_value, lower_bound);
+ }
+ }
+ else if (upper_bound != 0.0 && /* ignore upper_bound if it is 0.0 */
+ val > upper_bound) {
+ if (RTEST(ruby_verbose)) {
+ fprintf(stderr, "%s=%f (default value: %f) is ignored because it must be lower than %f.\n",
+ name, val, *default_value, upper_bound);
+ }
+ }
+ else {
+ goto accept;
+ }
+ }
+ return 0;
+
+ accept:
+ if (RTEST(ruby_verbose)) fprintf(stderr, "%s=%f (default value: %f)\n", name, val, *default_value);
+ *default_value = val;
+ return 1;
+}
+
+/*
+ * GC tuning environment variables
+ *
+ * * RUBY_GC_HEAP_FREE_SLOTS
+ * - Prepare at least this amount of slots after GC.
+ * - Allocate slots if there are not enough slots.
+ * * RUBY_GC_HEAP_GROWTH_FACTOR (new from 2.1)
+ * - Allocate slots by this factor.
+ * - (next slots number) = (current slots number) * (this factor)
+ * * RUBY_GC_HEAP_GROWTH_MAX_BYTES (was RUBY_GC_HEAP_GROWTH_MAX_SLOTS)
+ * - Allocation rate is limited to this number of bytes.
+ * * RUBY_GC_HEAP_FREE_SLOTS_MIN_RATIO (new from 2.4)
+ * - Allocate additional pages when the number of free slots is
+ * lower than the value (total_slots * (this ratio)).
+ * * RUBY_GC_HEAP_FREE_SLOTS_GOAL_RATIO (new from 2.4)
+ * - Allocate slots to satisfy this formula:
+ * free_slots = total_slots * goal_ratio
+ * - In other words, prepare (total_slots * goal_ratio) free slots.
+ * - if this value is 0.0, then use RUBY_GC_HEAP_GROWTH_FACTOR directly.
+ * * RUBY_GC_HEAP_FREE_SLOTS_MAX_RATIO (new from 2.4)
+ * - Allow to free pages when the number of free slots is
+ * greater than the value (total_slots * (this ratio)).
+ * * RUBY_GC_HEAP_OLDOBJECT_LIMIT_FACTOR (new from 2.1.1)
+ * - Do full GC when the number of old objects is more than R * N
+ * where R is this factor and
+ * N is the number of old objects just after last full GC.
+ *
+ * * obsolete
+ * * RUBY_FREE_MIN -> RUBY_GC_HEAP_FREE_SLOTS (from 2.1)
+ * * RUBY_HEAP_MIN_SLOTS -> RUBY_GC_HEAP_INIT_SLOTS (from 2.1) -> RUBY_GC_HEAP_INIT_BYTES
+ *
+ * * RUBY_GC_MALLOC_LIMIT
+ * * RUBY_GC_MALLOC_LIMIT_MAX (new from 2.1)
+ * * RUBY_GC_MALLOC_LIMIT_GROWTH_FACTOR (new from 2.1)
+ *
+ * * RUBY_GC_OLDMALLOC_LIMIT (new from 2.1)
+ * * RUBY_GC_OLDMALLOC_LIMIT_MAX (new from 2.1)
+ * * RUBY_GC_OLDMALLOC_LIMIT_GROWTH_FACTOR (new from 2.1)
+ */
+
+void
+rb_gc_impl_set_params(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ /* RUBY_GC_HEAP_FREE_SLOTS */
+ if (get_envparam_size("RUBY_GC_HEAP_FREE_SLOTS", &gc_params.heap_free_slots, 0)) {
+ /* ok */
+ }
+
+ get_envparam_size("RUBY_GC_HEAP_INIT_BYTES", &gc_params.heap_init_bytes, 0);
+
+ get_envparam_double("RUBY_GC_HEAP_GROWTH_FACTOR", &gc_params.growth_factor, 1.0, 0.0, FALSE);
+ get_envparam_size ("RUBY_GC_HEAP_GROWTH_MAX_BYTES", &gc_params.growth_max_bytes, 0);
+ get_envparam_double("RUBY_GC_HEAP_FREE_SLOTS_MIN_RATIO", &gc_params.heap_free_slots_min_ratio,
+ 0.0, 1.0, FALSE);
+ get_envparam_double("RUBY_GC_HEAP_FREE_SLOTS_MAX_RATIO", &gc_params.heap_free_slots_max_ratio,
+ gc_params.heap_free_slots_min_ratio, 1.0, FALSE);
+ get_envparam_double("RUBY_GC_HEAP_FREE_SLOTS_GOAL_RATIO", &gc_params.heap_free_slots_goal_ratio,
+ gc_params.heap_free_slots_min_ratio, gc_params.heap_free_slots_max_ratio, TRUE);
+ get_envparam_double("RUBY_GC_HEAP_OLDOBJECT_LIMIT_FACTOR", &gc_params.oldobject_limit_factor, 0.0, 0.0, TRUE);
+ get_envparam_double("RUBY_GC_HEAP_REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO", &gc_params.uncollectible_wb_unprotected_objects_limit_ratio, 0.0, 0.0, TRUE);
+
+ if (get_envparam_size("RUBY_GC_MALLOC_LIMIT", &gc_params.malloc_limit_min, 0)) {
+ malloc_limit = gc_params.malloc_limit_min;
+ }
+ get_envparam_size ("RUBY_GC_MALLOC_LIMIT_MAX", &gc_params.malloc_limit_max, 0);
+ if (!gc_params.malloc_limit_max) { /* ignore max-check if 0 */
+ gc_params.malloc_limit_max = SIZE_MAX;
+ }
+ get_envparam_double("RUBY_GC_MALLOC_LIMIT_GROWTH_FACTOR", &gc_params.malloc_limit_growth_factor, 1.0, 0.0, FALSE);
+
+#if RGENGC_ESTIMATE_OLDMALLOC
+ if (get_envparam_size("RUBY_GC_OLDMALLOC_LIMIT", &gc_params.oldmalloc_limit_min, 0)) {
+ objspace->rgengc.oldmalloc_increase_limit = gc_params.oldmalloc_limit_min;
+ }
+ get_envparam_size ("RUBY_GC_OLDMALLOC_LIMIT_MAX", &gc_params.oldmalloc_limit_max, 0);
+ get_envparam_double("RUBY_GC_OLDMALLOC_LIMIT_GROWTH_FACTOR", &gc_params.oldmalloc_limit_growth_factor, 1.0, 0.0, FALSE);
+#endif
+}
+
+static inline size_t
+objspace_malloc_size(rb_objspace_t *objspace, void *ptr, size_t hint)
+{
+#ifdef HAVE_MALLOC_USABLE_SIZE
+ if (!hint) {
+ hint = malloc_usable_size(ptr);
+ }
+#endif
+ return hint;
+}
+
+enum memop_type {
+ MEMOP_TYPE_MALLOC = 0,
+ MEMOP_TYPE_FREE,
+ MEMOP_TYPE_REALLOC
+};
+
+static inline void
+atomic_sub_nounderflow(size_t *var, size_t sub)
+{
+ if (sub == 0) return;
+
+ while (1) {
+ size_t val = *var;
+ if (val < sub) sub = val;
+ if (RUBY_ATOMIC_SIZE_CAS(*var, val, val-sub) == val) break;
+ }
+}
+
+#define gc_stress_full_mark_after_malloc_p() \
+ (FIXNUM_P(ruby_gc_stress_mode) && (FIX2LONG(ruby_gc_stress_mode) & (1<<gc_stress_full_mark_after_malloc)))
+
+static void
+objspace_malloc_gc_stress(rb_objspace_t *objspace)
+{
+ if (ruby_gc_stressful && ruby_native_thread_p()) {
+ unsigned int reason = (GPR_FLAG_IMMEDIATE_MARK | GPR_FLAG_IMMEDIATE_SWEEP |
+ GPR_FLAG_STRESS | GPR_FLAG_MALLOC);
+
+ if (gc_stress_full_mark_after_malloc_p()) {
+ reason |= GPR_FLAG_FULL_MARK;
+ }
+ garbage_collect_with_gvl(objspace, reason);
+ }
+}
+
+static void
+malloc_increase_commit(rb_objspace_t *objspace, size_t new_size, size_t old_size)
+{
+ if (new_size > old_size) {
+ size_t delta = new_size - old_size;
+ MALLOC_COUNTERS_LOCK(objspace);
+ gc_counter_add(&objspace->malloc_counters.counters.malloc, delta);
+#if RGENGC_ESTIMATE_OLDMALLOC
+ gc_counter_add(&objspace->malloc_counters.oldcounters.malloc, delta);
+#endif
+ MALLOC_COUNTERS_UNLOCK(objspace);
+ }
+ else if (old_size > new_size) {
+ size_t delta = old_size - new_size;
+ MALLOC_COUNTERS_LOCK(objspace);
+ gc_counter_add(&objspace->malloc_counters.counters.free, delta);
+#if RGENGC_ESTIMATE_OLDMALLOC
+ gc_counter_add(&objspace->malloc_counters.oldcounters.free, delta);
+#endif
+ MALLOC_COUNTERS_UNLOCK(objspace);
+ }
+}
+
+#if USE_MALLOC_INCREASE_LOCAL
+static void
+malloc_increase_local_flush(rb_objspace_t *objspace)
+{
+ int delta = malloc_increase_local;
+ if (delta == 0) return;
+
+ malloc_increase_local = 0;
+ if (delta > 0) {
+ malloc_increase_commit(objspace, (size_t)delta, 0);
+ }
+ else {
+ malloc_increase_commit(objspace, 0, (size_t)(-delta));
+ }
+}
+#else
+static void
+malloc_increase_local_flush(rb_objspace_t *objspace)
+{
+}
+#endif
+
+static inline bool
+objspace_malloc_increase_report(rb_objspace_t *objspace, void *mem, size_t new_size, size_t old_size, enum memop_type type, bool gc_allowed)
+{
+ if (0) fprintf(stderr, "increase - ptr: %p, type: %s, new_size: %"PRIdSIZE", old_size: %"PRIdSIZE"\n",
+ mem,
+ type == MEMOP_TYPE_MALLOC ? "malloc" :
+ type == MEMOP_TYPE_FREE ? "free " :
+ type == MEMOP_TYPE_REALLOC ? "realloc": "error",
+ new_size, old_size);
+ return false;
+}
+
+static bool
+objspace_malloc_increase_body(rb_objspace_t *objspace, void *mem, size_t new_size, size_t old_size, enum memop_type type, bool gc_allowed)
+{
+#if USE_MALLOC_INCREASE_LOCAL
+ if (new_size < GC_MALLOC_INCREASE_LOCAL_THRESHOLD &&
+ old_size < GC_MALLOC_INCREASE_LOCAL_THRESHOLD) {
+ malloc_increase_local += (int)new_size - (int)old_size;
+
+ if (malloc_increase_local >= GC_MALLOC_INCREASE_LOCAL_THRESHOLD ||
+ malloc_increase_local <= -GC_MALLOC_INCREASE_LOCAL_THRESHOLD) {
+ malloc_increase_local_flush(objspace);
+ }
+ }
+ else {
+ malloc_increase_local_flush(objspace);
+ malloc_increase_commit(objspace, new_size, old_size);
+ }
+#else
+ malloc_increase_commit(objspace, new_size, old_size);
+#endif
+
+ if (type == MEMOP_TYPE_MALLOC && gc_allowed) {
+ retry:
+ if (malloc_increase > malloc_limit && ruby_native_thread_p() && !dont_gc_val()) {
+ if (ruby_thread_has_gvl_p() && is_lazy_sweeping(objspace)) {
+ gc_rest(objspace); /* gc_rest can reduce malloc_increase */
+ goto retry;
+ }
+ garbage_collect_with_gvl(objspace, GPR_FLAG_MALLOC);
+ }
+ }
+
+#if MALLOC_ALLOCATED_SIZE
+ if (new_size >= old_size) {
+ RUBY_ATOMIC_SIZE_ADD(objspace->malloc_params.allocated_size, new_size - old_size);
+ }
+ else {
+ size_t dec_size = old_size - new_size;
+
+#if MALLOC_ALLOCATED_SIZE_CHECK
+ size_t allocated_size = objspace->malloc_params.allocated_size;
+ if (allocated_size < dec_size) {
+ rb_bug("objspace_malloc_increase: underflow malloc_params.allocated_size.");
+ }
+#endif
+ atomic_sub_nounderflow(&objspace->malloc_params.allocated_size, dec_size);
+ }
+
+ switch (type) {
+ case MEMOP_TYPE_MALLOC:
+ RUBY_ATOMIC_SIZE_INC(objspace->malloc_params.allocations);
+ break;
+ case MEMOP_TYPE_FREE:
+ {
+ size_t allocations = objspace->malloc_params.allocations;
+ if (allocations > 0) {
+ atomic_sub_nounderflow(&objspace->malloc_params.allocations, 1);
+ }
+#if MALLOC_ALLOCATED_SIZE_CHECK
+ else {
+ GC_ASSERT(objspace->malloc_params.allocations > 0);
+ }
+#endif
+ }
+ break;
+ case MEMOP_TYPE_REALLOC: /* ignore */ break;
+ }
+#endif
+ return true;
+}
+
+#define objspace_malloc_increase(...) \
+ for (bool malloc_increase_done = objspace_malloc_increase_report(__VA_ARGS__); \
+ !malloc_increase_done; \
+ malloc_increase_done = objspace_malloc_increase_body(__VA_ARGS__))
+
+struct malloc_obj_info { /* 4 words */
+ size_t size;
+};
+
+static inline size_t
+objspace_malloc_prepare(rb_objspace_t *objspace, size_t size)
+{
+ if (size == 0) size = 1;
+
+#if CALC_EXACT_MALLOC_SIZE
+ size += sizeof(struct malloc_obj_info);
+#endif
+
+ return size;
+}
+
+static bool
+malloc_during_gc_p(rb_objspace_t *objspace)
+{
+ /* malloc is not allowed during GC when we're not using multiple ractors
+ * (since ractors can run while another thread is sweeping) and when we
+ * have the GVL (since if we don't have the GVL, we'll try to acquire the
+ * GVL which will block and ensure the other thread finishes GC). */
+ return during_gc && !dont_gc_val() && !rb_gc_multi_ractor_p() && ruby_thread_has_gvl_p();
+}
+
+static inline void *
+objspace_malloc_fixup(rb_objspace_t *objspace, void *mem, size_t size, bool gc_allowed)
+{
+ size = objspace_malloc_size(objspace, mem, size);
+ objspace_malloc_increase(objspace, mem, size, 0, MEMOP_TYPE_MALLOC, gc_allowed) {}
+
+#if CALC_EXACT_MALLOC_SIZE
+ {
+ struct malloc_obj_info *info = mem;
+ info->size = size;
+ mem = info + 1;
+ }
+#endif
+
+ return mem;
+}
+
+#if defined(__GNUC__) && RUBY_DEBUG
+#define RB_BUG_INSTEAD_OF_RB_MEMERROR 1
+#endif
+
+#ifndef RB_BUG_INSTEAD_OF_RB_MEMERROR
+# define RB_BUG_INSTEAD_OF_RB_MEMERROR 0
+#endif
+
+#define GC_MEMERROR(...) \
+ ((RB_BUG_INSTEAD_OF_RB_MEMERROR+0) ? rb_bug("" __VA_ARGS__) : (void)0)
+
+#define TRY_WITH_GC(siz, expr) do { \
+ const gc_profile_record_flag gpr = \
+ GPR_FLAG_FULL_MARK | \
+ GPR_FLAG_IMMEDIATE_MARK | \
+ GPR_FLAG_IMMEDIATE_SWEEP | \
+ GPR_FLAG_MALLOC; \
+ objspace_malloc_gc_stress(objspace); \
+ \
+ if (RB_LIKELY((expr))) { \
+ /* Success on 1st try */ \
+ } \
+ else if (gc_allowed && !garbage_collect_with_gvl(objspace, gpr)) { \
+ /* @shyouhei thinks this doesn't happen */ \
+ GC_MEMERROR("TRY_WITH_GC: could not GC"); \
+ } \
+ else if ((expr)) { \
+ /* Success on 2nd try */ \
+ } \
+ else { \
+ GC_MEMERROR("TRY_WITH_GC: could not allocate:" \
+ "%"PRIdSIZE" bytes for %s", \
+ siz, # expr); \
+ } \
+ } while (0)
+
+static void
+check_malloc_not_in_gc(rb_objspace_t *objspace, const char *msg)
+{
+ if (RB_UNLIKELY(malloc_during_gc_p(objspace))) {
+ dont_gc_on();
+ during_gc = false;
+ rb_bug("Cannot %s during GC", msg);
+ }
+}
+
+void
+rb_gc_impl_free(void *objspace_ptr, void *ptr, size_t old_size)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (!ptr) {
+ /*
+ * ISO/IEC 9899 says "If ptr is a null pointer, no action occurs" since
+ * its first version. We would better follow.
+ */
+ return;
+ }
+#if CALC_EXACT_MALLOC_SIZE
+ struct malloc_obj_info *info = (struct malloc_obj_info *)ptr - 1;
+#if VERIFY_FREE_SIZE
+ if (!info->size) {
+ rb_bug("buffer %p has no recorded size. Was it allocated with ruby_mimalloc? If so it should be freed with ruby_mimfree", ptr);
+ }
+
+ if (old_size && (old_size + sizeof(struct malloc_obj_info)) != info->size) {
+ rb_bug("buffer %p freed with old_size=%zu, but was allocated with size=%zu", ptr, old_size, info->size - sizeof(struct malloc_obj_info));
+ }
+#endif
+ ptr = info;
+ old_size = info->size;
+#endif
+ old_size = objspace_malloc_size(objspace, ptr, old_size);
+
+ objspace_malloc_increase(objspace, ptr, 0, old_size, MEMOP_TYPE_FREE, true) {
+ free(ptr);
+ ptr = NULL;
+ RB_DEBUG_COUNTER_INC(heap_xfree);
+ }
+}
+
+void *
+rb_gc_impl_malloc(void *objspace_ptr, size_t size, bool gc_allowed)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+ check_malloc_not_in_gc(objspace, "malloc");
+
+ void *mem;
+
+ size = objspace_malloc_prepare(objspace, size);
+ TRY_WITH_GC(size, mem = malloc(size));
+ RB_DEBUG_COUNTER_INC(heap_xmalloc);
+ if (!mem) return mem;
+ return objspace_malloc_fixup(objspace, mem, size, gc_allowed);
+}
+
+void *
+rb_gc_impl_calloc(void *objspace_ptr, size_t size, bool gc_allowed)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (RB_UNLIKELY(malloc_during_gc_p(objspace))) {
+ rb_warn("calloc during GC detected, this could cause crashes if it triggers another GC");
+#if RGENGC_CHECK_MODE || RUBY_DEBUG
+ rb_bug("Cannot calloc during GC");
+#endif
+ }
+
+ void *mem;
+
+ size = objspace_malloc_prepare(objspace, size);
+ TRY_WITH_GC(size, mem = calloc1(size));
+ if (!mem) return mem;
+ return objspace_malloc_fixup(objspace, mem, size, gc_allowed);
+}
+
+void *
+rb_gc_impl_realloc(void *objspace_ptr, void *ptr, size_t new_size, size_t old_size, bool gc_allowed)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ check_malloc_not_in_gc(objspace, "realloc");
+
+ void *mem;
+
+ if (!ptr) return rb_gc_impl_malloc(objspace, new_size, gc_allowed);
+
+ /*
+ * The behavior of realloc(ptr, 0) is implementation defined.
+ * Therefore we don't use realloc(ptr, 0) for portability reason.
+ * see http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_400.htm
+ */
+ if (new_size == 0) {
+ if ((mem = rb_gc_impl_malloc(objspace, 0, gc_allowed)) != NULL) {
+ /*
+ * - OpenBSD's malloc(3) man page says that when 0 is passed, it
+ * returns a non-NULL pointer to an access-protected memory page.
+ * The returned pointer cannot be read / written at all, but
+ * still be a valid argument of free().
+ *
+ * https://man.openbsd.org/malloc.3
+ *
+ * - Linux's malloc(3) man page says that it _might_ perhaps return
+ * a non-NULL pointer when its argument is 0. That return value
+ * is safe (and is expected) to be passed to free().
+ *
+ * https://man7.org/linux/man-pages/man3/malloc.3.html
+ *
+ * - As I read the implementation jemalloc's malloc() returns fully
+ * normal 16 bytes memory region when its argument is 0.
+ *
+ * - As I read the implementation musl libc's malloc() returns
+ * fully normal 32 bytes memory region when its argument is 0.
+ *
+ * - Other malloc implementations can also return non-NULL.
+ */
+ rb_gc_impl_free(objspace, ptr, old_size);
+ return mem;
+ }
+ else {
+ /*
+ * It is dangerous to return NULL here, because that could lead to
+ * RCE. Fallback to 1 byte instead of zero.
+ *
+ * https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-11932
+ */
+ new_size = 1;
+ }
+ }
+
+#if CALC_EXACT_MALLOC_SIZE
+ {
+ struct malloc_obj_info *info = (struct malloc_obj_info *)ptr - 1;
+ new_size += sizeof(struct malloc_obj_info);
+ ptr = info;
+#if VERIFY_FREE_SIZE
+ if (old_size && (old_size + sizeof(struct malloc_obj_info)) != info->size) {
+ rb_bug("buffer %p realloced with old_size=%zu, but was allocated with size=%zu", ptr, old_size, info->size - sizeof(struct malloc_obj_info));
+ }
+#endif
+ old_size = info->size;
+ }
+#endif
+
+ old_size = objspace_malloc_size(objspace, ptr, old_size);
+ TRY_WITH_GC(new_size, mem = RB_GNUC_EXTENSION_BLOCK(realloc(ptr, new_size)));
+ if (!mem) return mem;
+ new_size = objspace_malloc_size(objspace, mem, new_size);
+
+#if CALC_EXACT_MALLOC_SIZE
+ {
+ struct malloc_obj_info *info = mem;
+ info->size = new_size;
+ mem = info + 1;
+ }
+#endif
+
+ objspace_malloc_increase(objspace, mem, new_size, old_size, MEMOP_TYPE_REALLOC, gc_allowed);
+
+ RB_DEBUG_COUNTER_INC(heap_xrealloc);
+ return mem;
+}
+
+void
+rb_gc_impl_adjust_memory_usage(void *objspace_ptr, ssize_t diff)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (diff > 0) {
+ objspace_malloc_increase(objspace, 0, diff, 0, MEMOP_TYPE_REALLOC, true);
+ }
+ else if (diff < 0) {
+ objspace_malloc_increase(objspace, 0, 0, -diff, MEMOP_TYPE_REALLOC, true);
+ }
+}
+
+// TODO: move GC profiler stuff back into gc.c
+/*
+ ------------------------------ GC profiler ------------------------------
+*/
+
+#define GC_PROFILE_RECORD_DEFAULT_SIZE 100
+
+static bool
+current_process_time(struct timespec *ts)
+{
+#if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_PROCESS_CPUTIME_ID)
+ {
+ static int try_clock_gettime = 1;
+ if (try_clock_gettime && clock_gettime(CLOCK_PROCESS_CPUTIME_ID, ts) == 0) {
+ return true;
+ }
+ else {
+ try_clock_gettime = 0;
+ }
+ }
+#endif
+
+#ifdef RUSAGE_SELF
+ {
+ struct rusage usage;
+ struct timeval time;
+ if (getrusage(RUSAGE_SELF, &usage) == 0) {
+ time = usage.ru_utime;
+ ts->tv_sec = time.tv_sec;
+ ts->tv_nsec = (int32_t)time.tv_usec * 1000;
+ return true;
+ }
+ }
+#endif
+
+#ifdef _WIN32
+ {
+ FILETIME creation_time, exit_time, kernel_time, user_time;
+ ULARGE_INTEGER ui;
+
+ if (GetProcessTimes(GetCurrentProcess(),
+ &creation_time, &exit_time, &kernel_time, &user_time) != 0) {
+ memcpy(&ui, &user_time, sizeof(FILETIME));
+#define PER100NSEC (uint64_t)(1000 * 1000 * 10)
+ ts->tv_nsec = (long)(ui.QuadPart % PER100NSEC);
+ ts->tv_sec = (time_t)(ui.QuadPart / PER100NSEC);
+ return true;
+ }
+ }
+#endif
+
+ return false;
+}
+
+static double
+getrusage_time(void)
+{
+ struct timespec ts;
+ if (current_process_time(&ts)) {
+ return ts.tv_sec + ts.tv_nsec * 1e-9;
+ }
+ else {
+ return 0.0;
+ }
+}
+
+
+static inline void
+gc_prof_setup_new_record(rb_objspace_t *objspace, unsigned int reason)
+{
+ if (objspace->profile.run) {
+ size_t index = objspace->profile.next_index;
+ gc_profile_record *record;
+
+ /* create new record */
+ objspace->profile.next_index++;
+
+ if (!objspace->profile.records) {
+ objspace->profile.size = GC_PROFILE_RECORD_DEFAULT_SIZE;
+ objspace->profile.records = malloc(xmalloc2_size(sizeof(gc_profile_record), objspace->profile.size));
+ }
+ if (index >= objspace->profile.size) {
+ void *ptr;
+ objspace->profile.size += 1000;
+ ptr = realloc(objspace->profile.records, xmalloc2_size(sizeof(gc_profile_record), objspace->profile.size));
+ if (!ptr) rb_memerror();
+ objspace->profile.records = ptr;
+ }
+ if (!objspace->profile.records) {
+ rb_bug("gc_profile malloc or realloc miss");
+ }
+ record = objspace->profile.current_record = &objspace->profile.records[objspace->profile.next_index - 1];
+ MEMZERO(record, gc_profile_record, 1);
+
+ /* setup before-GC parameter */
+ record->flags = reason | (ruby_gc_stressful ? GPR_FLAG_STRESS : 0);
+#if MALLOC_ALLOCATED_SIZE
+ record->allocated_size = malloc_allocated_size;
+#endif
+#if GC_PROFILE_MORE_DETAIL && GC_PROFILE_DETAIL_MEMORY
+#ifdef RUSAGE_SELF
+ {
+ struct rusage usage;
+ if (getrusage(RUSAGE_SELF, &usage) == 0) {
+ record->maxrss = usage.ru_maxrss;
+ record->minflt = usage.ru_minflt;
+ record->majflt = usage.ru_majflt;
+ }
+ }
+#endif
+#endif
+ }
+}
+
+static inline void
+gc_prof_timer_start(rb_objspace_t *objspace)
+{
+ if (gc_prof_enabled(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+#if GC_PROFILE_MORE_DETAIL
+ record->prepare_time = objspace->profile.prepare_time;
+#endif
+ record->gc_time = 0;
+ record->gc_invoke_time = getrusage_time();
+ }
+}
+
+static double
+elapsed_time_from(double time)
+{
+ double now = getrusage_time();
+ if (now > time) {
+ return now - time;
+ }
+ else {
+ return 0;
+ }
+}
+
+static inline void
+gc_prof_timer_stop(rb_objspace_t *objspace)
+{
+ if (gc_prof_enabled(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+ record->gc_time = elapsed_time_from(record->gc_invoke_time);
+ record->gc_invoke_time -= objspace->profile.invoke_time;
+ }
+}
+
+#ifdef BUILDING_MODULAR_GC
+# define RUBY_DTRACE_GC_HOOK(name)
+#else
+# define RUBY_DTRACE_GC_HOOK(name) \
+ do {if (RUBY_DTRACE_GC_##name##_ENABLED()) RUBY_DTRACE_GC_##name();} while (0)
+#endif
+
+static inline void
+gc_prof_mark_timer_start(rb_objspace_t *objspace)
+{
+ RUBY_DTRACE_GC_HOOK(MARK_BEGIN);
+#if GC_PROFILE_MORE_DETAIL
+ if (gc_prof_enabled(objspace)) {
+ gc_prof_record(objspace)->gc_mark_time = getrusage_time();
+ }
+#endif
+}
+
+static inline void
+gc_prof_mark_timer_stop(rb_objspace_t *objspace)
+{
+ RUBY_DTRACE_GC_HOOK(MARK_END);
+#if GC_PROFILE_MORE_DETAIL
+ if (gc_prof_enabled(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+ record->gc_mark_time = elapsed_time_from(record->gc_mark_time);
+ }
+#endif
+}
+
+static inline void
+gc_prof_sweep_timer_start(rb_objspace_t *objspace)
+{
+ RUBY_DTRACE_GC_HOOK(SWEEP_BEGIN);
+ if (gc_prof_enabled(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+
+ if (record->gc_time > 0 || GC_PROFILE_MORE_DETAIL) {
+ objspace->profile.gc_sweep_start_time = getrusage_time();
+ }
+ }
+}
+
+static inline void
+gc_prof_sweep_timer_stop(rb_objspace_t *objspace)
+{
+ RUBY_DTRACE_GC_HOOK(SWEEP_END);
+
+ if (gc_prof_enabled(objspace)) {
+ double sweep_time;
+ gc_profile_record *record = gc_prof_record(objspace);
+
+ if (record->gc_time > 0) {
+ sweep_time = elapsed_time_from(objspace->profile.gc_sweep_start_time);
+ /* need to accumulate GC time for lazy sweep after gc() */
+ record->gc_time += sweep_time;
+ }
+ else if (GC_PROFILE_MORE_DETAIL) {
+ sweep_time = elapsed_time_from(objspace->profile.gc_sweep_start_time);
+ }
+
+#if GC_PROFILE_MORE_DETAIL
+ record->gc_sweep_time += sweep_time;
+ if (heap_pages_deferred_final) record->flags |= GPR_FLAG_HAVE_FINALIZE;
+#endif
+ if (heap_pages_deferred_final) objspace->profile.latest_gc_info |= GPR_FLAG_HAVE_FINALIZE;
+ }
+}
+
+static inline void
+gc_prof_set_malloc_info(rb_objspace_t *objspace)
+{
+#if GC_PROFILE_MORE_DETAIL
+ if (gc_prof_enabled(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+ record->allocate_increase = malloc_increase;
+ record->allocate_limit = malloc_limit;
+ }
+#endif
+}
+
+static inline void
+gc_prof_set_heap_info(rb_objspace_t *objspace)
+{
+ if (gc_prof_enabled(objspace)) {
+ gc_profile_record *record = gc_prof_record(objspace);
+
+ /* Sum across all size pools since each has a different slot size. */
+ size_t total = 0;
+ size_t use_size = 0;
+ size_t total_size = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ size_t heap_live = heap->total_allocated_objects - heap->total_freed_objects - heap->final_slots_count;
+ total += heap->total_slots;
+ use_size += heap_live * heap->slot_size;
+ total_size += heap->total_slots * heap->slot_size;
+ }
+
+#if GC_PROFILE_MORE_DETAIL
+ size_t live = objspace->profile.total_allocated_objects_at_gc_start - total_freed_objects(objspace);
+ record->heap_use_pages = objspace->profile.heap_used_at_gc_start;
+ record->heap_live_objects = live;
+ record->heap_free_objects = total - live;
+#endif
+
+ record->heap_total_objects = total;
+ record->heap_use_size = use_size;
+ record->heap_total_size = total_size;
+ }
+}
+
+/*
+ * call-seq:
+ * GC::Profiler.clear -> nil
+ *
+ * Clears the \GC profiler data.
+ *
+ */
+
+static VALUE
+gc_profile_clear(VALUE _)
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+ void *p = objspace->profile.records;
+ objspace->profile.records = NULL;
+ objspace->profile.size = 0;
+ objspace->profile.next_index = 0;
+ objspace->profile.current_record = 0;
+ free(p);
+ return Qnil;
+}
+
+/*
+ * call-seq:
+ * GC::Profiler.raw_data -> [Hash, ...]
+ *
+ * Returns an Array of individual raw profile data Hashes ordered
+ * from earliest to latest by +:GC_INVOKE_TIME+.
+ *
+ * For example:
+ *
+ * [
+ * {
+ * :GC_TIME=>1.3000000000000858e-05,
+ * :GC_INVOKE_TIME=>0.010634999999999999,
+ * :HEAP_USE_SIZE=>289640,
+ * :HEAP_TOTAL_SIZE=>588960,
+ * :HEAP_TOTAL_OBJECTS=>14724,
+ * :GC_IS_MARKED=>false
+ * },
+ * # ...
+ * ]
+ *
+ * The keys mean:
+ *
+ * +:GC_TIME+::
+ * Time elapsed in seconds for this GC run
+ * +:GC_INVOKE_TIME+::
+ * Time elapsed in seconds from startup to when the GC was invoked
+ * +:HEAP_USE_SIZE+::
+ * Total bytes of heap used
+ * +:HEAP_TOTAL_SIZE+::
+ * Total size of heap in bytes
+ * +:HEAP_TOTAL_OBJECTS+::
+ * Total number of objects
+ * +:GC_IS_MARKED+::
+ * Returns +true+ if the GC is in mark phase
+ *
+ * If ruby was built with +GC_PROFILE_MORE_DETAIL+, you will also have access
+ * to the following hash keys:
+ *
+ * +:GC_MARK_TIME+::
+ * +:GC_SWEEP_TIME+::
+ * +:ALLOCATE_INCREASE+::
+ * +:ALLOCATE_LIMIT+::
+ * +:HEAP_USE_PAGES+::
+ * +:HEAP_LIVE_OBJECTS+::
+ * +:HEAP_FREE_OBJECTS+::
+ * +:HAVE_FINALIZE+::
+ *
+ */
+
+static VALUE
+gc_profile_record_get(VALUE _)
+{
+ VALUE prof;
+ VALUE gc_profile = rb_ary_new();
+ size_t i;
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+
+ if (!objspace->profile.run) {
+ return Qnil;
+ }
+
+ for (i =0; i < objspace->profile.next_index; i++) {
+ gc_profile_record *record = &objspace->profile.records[i];
+
+ prof = rb_hash_new();
+ rb_hash_aset(prof, ID2SYM(rb_intern("GC_FLAGS")), gc_info_decode(objspace, rb_hash_new(), record->flags));
+ rb_hash_aset(prof, ID2SYM(rb_intern("GC_TIME")), DBL2NUM(record->gc_time));
+ rb_hash_aset(prof, ID2SYM(rb_intern("GC_INVOKE_TIME")), DBL2NUM(record->gc_invoke_time));
+ rb_hash_aset(prof, ID2SYM(rb_intern("HEAP_USE_SIZE")), SIZET2NUM(record->heap_use_size));
+ rb_hash_aset(prof, ID2SYM(rb_intern("HEAP_TOTAL_SIZE")), SIZET2NUM(record->heap_total_size));
+ rb_hash_aset(prof, ID2SYM(rb_intern("HEAP_TOTAL_OBJECTS")), SIZET2NUM(record->heap_total_objects));
+ rb_hash_aset(prof, ID2SYM(rb_intern("MOVED_OBJECTS")), SIZET2NUM(record->moved_objects));
+ rb_hash_aset(prof, ID2SYM(rb_intern("GC_IS_MARKED")), Qtrue);
+#if GC_PROFILE_MORE_DETAIL
+ rb_hash_aset(prof, ID2SYM(rb_intern("GC_MARK_TIME")), DBL2NUM(record->gc_mark_time));
+ rb_hash_aset(prof, ID2SYM(rb_intern("GC_SWEEP_TIME")), DBL2NUM(record->gc_sweep_time));
+ rb_hash_aset(prof, ID2SYM(rb_intern("ALLOCATE_INCREASE")), SIZET2NUM(record->allocate_increase));
+ rb_hash_aset(prof, ID2SYM(rb_intern("ALLOCATE_LIMIT")), SIZET2NUM(record->allocate_limit));
+ rb_hash_aset(prof, ID2SYM(rb_intern("HEAP_USE_PAGES")), SIZET2NUM(record->heap_use_pages));
+ rb_hash_aset(prof, ID2SYM(rb_intern("HEAP_LIVE_OBJECTS")), SIZET2NUM(record->heap_live_objects));
+ rb_hash_aset(prof, ID2SYM(rb_intern("HEAP_FREE_OBJECTS")), SIZET2NUM(record->heap_free_objects));
+
+ rb_hash_aset(prof, ID2SYM(rb_intern("REMOVING_OBJECTS")), SIZET2NUM(record->removing_objects));
+ rb_hash_aset(prof, ID2SYM(rb_intern("EMPTY_OBJECTS")), SIZET2NUM(record->empty_objects));
+
+ rb_hash_aset(prof, ID2SYM(rb_intern("HAVE_FINALIZE")), (record->flags & GPR_FLAG_HAVE_FINALIZE) ? Qtrue : Qfalse);
+#endif
+
+#if RGENGC_PROFILE > 0
+ rb_hash_aset(prof, ID2SYM(rb_intern("OLD_OBJECTS")), SIZET2NUM(record->old_objects));
+ rb_hash_aset(prof, ID2SYM(rb_intern("REMEMBERED_NORMAL_OBJECTS")), SIZET2NUM(record->remembered_normal_objects));
+ rb_hash_aset(prof, ID2SYM(rb_intern("REMEMBERED_SHADY_OBJECTS")), SIZET2NUM(record->remembered_shady_objects));
+#endif
+ rb_ary_push(gc_profile, prof);
+ }
+
+ return gc_profile;
+}
+
+#if GC_PROFILE_MORE_DETAIL
+#define MAJOR_REASON_MAX 0x10
+
+static char *
+gc_profile_dump_major_reason(unsigned int flags, char *buff)
+{
+ unsigned int reason = flags & GPR_FLAG_MAJOR_MASK;
+ int i = 0;
+
+ if (reason == GPR_FLAG_NONE) {
+ buff[0] = '-';
+ buff[1] = 0;
+ }
+ else {
+#define C(x, s) \
+ if (reason & GPR_FLAG_MAJOR_BY_##x) { \
+ buff[i++] = #x[0]; \
+ if (i >= MAJOR_REASON_MAX) rb_bug("gc_profile_dump_major_reason: overflow"); \
+ buff[i] = 0; \
+ }
+ C(NOFREE, N);
+ C(OLDGEN, O);
+ C(SHADY, S);
+#if RGENGC_ESTIMATE_OLDMALLOC
+ C(OLDMALLOC, M);
+#endif
+#undef C
+ }
+ return buff;
+}
+#endif
+
+
+
+static void
+gc_profile_dump_on(VALUE out, VALUE (*append)(VALUE, VALUE))
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+ size_t count = objspace->profile.next_index;
+#ifdef MAJOR_REASON_MAX
+ char reason_str[MAJOR_REASON_MAX];
+#endif
+
+ if (objspace->profile.run && count /* > 1 */) {
+ size_t i;
+ const gc_profile_record *record;
+
+ append(out, rb_sprintf("GC %"PRIuSIZE" invokes.\n", objspace->profile.count));
+ append(out, rb_str_new_cstr("Index Invoke Time(sec) Use Size(byte) Total Size(byte) Total Object GC Time(ms)\n"));
+
+ for (i = 0; i < count; i++) {
+ record = &objspace->profile.records[i];
+ append(out, rb_sprintf("%5"PRIuSIZE" %19.3f %20"PRIuSIZE" %20"PRIuSIZE" %20"PRIuSIZE" %30.20f\n",
+ i+1, record->gc_invoke_time, record->heap_use_size,
+ record->heap_total_size, record->heap_total_objects, record->gc_time*1000));
+ }
+
+#if GC_PROFILE_MORE_DETAIL
+ const char *str = "\n\n" \
+ "More detail.\n" \
+ "Prepare Time = Previously GC's rest sweep time\n"
+ "Index Flags Allocate Inc. Allocate Limit"
+#if CALC_EXACT_MALLOC_SIZE
+ " Allocated Size"
+#endif
+ " Use Page Mark Time(ms) Sweep Time(ms) Prepare Time(ms) LivingObj FreeObj RemovedObj EmptyObj"
+#if RGENGC_PROFILE
+ " OldgenObj RemNormObj RemShadObj"
+#endif
+#if GC_PROFILE_DETAIL_MEMORY
+ " MaxRSS(KB) MinorFLT MajorFLT"
+#endif
+ "\n";
+ append(out, rb_str_new_cstr(str));
+
+ for (i = 0; i < count; i++) {
+ record = &objspace->profile.records[i];
+ append(out, rb_sprintf("%5"PRIuSIZE" %4s/%c/%6s%c %13"PRIuSIZE" %15"PRIuSIZE
+#if CALC_EXACT_MALLOC_SIZE
+ " %15"PRIuSIZE
+#endif
+ " %9"PRIuSIZE" %17.12f %17.12f %17.12f %10"PRIuSIZE" %10"PRIuSIZE" %10"PRIuSIZE" %10"PRIuSIZE
+#if RGENGC_PROFILE
+ "%10"PRIuSIZE" %10"PRIuSIZE" %10"PRIuSIZE
+#endif
+#if GC_PROFILE_DETAIL_MEMORY
+ "%11ld %8ld %8ld"
+#endif
+
+ "\n",
+ i+1,
+ gc_profile_dump_major_reason(record->flags, reason_str),
+ (record->flags & GPR_FLAG_HAVE_FINALIZE) ? 'F' : '.',
+ (record->flags & GPR_FLAG_NEWOBJ) ? "NEWOBJ" :
+ (record->flags & GPR_FLAG_MALLOC) ? "MALLOC" :
+ (record->flags & GPR_FLAG_METHOD) ? "METHOD" :
+ (record->flags & GPR_FLAG_CAPI) ? "CAPI__" : "??????",
+ (record->flags & GPR_FLAG_STRESS) ? '!' : ' ',
+ record->allocate_increase, record->allocate_limit,
+#if CALC_EXACT_MALLOC_SIZE
+ record->allocated_size,
+#endif
+ record->heap_use_pages,
+ record->gc_mark_time*1000,
+ record->gc_sweep_time*1000,
+ record->prepare_time*1000,
+
+ record->heap_live_objects,
+ record->heap_free_objects,
+ record->removing_objects,
+ record->empty_objects
+#if RGENGC_PROFILE
+ ,
+ record->old_objects,
+ record->remembered_normal_objects,
+ record->remembered_shady_objects
+#endif
+#if GC_PROFILE_DETAIL_MEMORY
+ ,
+ record->maxrss / 1024,
+ record->minflt,
+ record->majflt
+#endif
+
+ ));
+ }
+#endif
+ }
+}
+
+/*
+ * call-seq:
+ * GC::Profiler.result -> String
+ *
+ * Returns a profile data report such as:
+ *
+ * GC 1 invokes.
+ * Index Invoke Time(sec) Use Size(byte) Total Size(byte) Total Object GC time(ms)
+ * 1 0.012 159240 212940 10647 0.00000000000001530000
+ */
+
+static VALUE
+gc_profile_result(VALUE _)
+{
+ VALUE str = rb_str_buf_new(0);
+ gc_profile_dump_on(str, rb_str_buf_append);
+ return str;
+}
+
+/*
+ * call-seq:
+ * GC::Profiler.report
+ * GC::Profiler.report(io)
+ *
+ * Writes the GC::Profiler.result to <tt>$stdout</tt> or the given IO object.
+ *
+ */
+
+static VALUE
+gc_profile_report(int argc, VALUE *argv, VALUE self)
+{
+ VALUE out;
+
+ out = (!rb_check_arity(argc, 0, 1) ? rb_stdout : argv[0]);
+ gc_profile_dump_on(out, rb_io_write);
+
+ return Qnil;
+}
+
+/*
+ * call-seq:
+ * GC::Profiler.total_time -> float
+ *
+ * The total time used for garbage collection in seconds
+ */
+
+static VALUE
+gc_profile_total_time(VALUE self)
+{
+ double time = 0;
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+
+ if (objspace->profile.run && objspace->profile.next_index > 0) {
+ size_t i;
+ size_t count = objspace->profile.next_index;
+
+ for (i = 0; i < count; i++) {
+ time += objspace->profile.records[i].gc_time;
+ }
+ }
+ return DBL2NUM(time);
+}
+
+/*
+ * call-seq:
+ * GC::Profiler.enabled? -> true or false
+ *
+ * The current status of \GC profile mode.
+ */
+
+static VALUE
+gc_profile_enable_get(VALUE self)
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+ return objspace->profile.run ? Qtrue : Qfalse;
+}
+
+/*
+ * call-seq:
+ * GC::Profiler.enable -> nil
+ *
+ * Starts the \GC profiler.
+ *
+ */
+
+static VALUE
+gc_profile_enable(VALUE _)
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+ objspace->profile.run = TRUE;
+ objspace->profile.current_record = 0;
+ return Qnil;
+}
+
+/*
+ * call-seq:
+ * GC::Profiler.disable -> nil
+ *
+ * Stops the \GC profiler.
+ *
+ */
+
+static VALUE
+gc_profile_disable(VALUE _)
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+
+ objspace->profile.run = FALSE;
+ objspace->profile.current_record = 0;
+ return Qnil;
+}
+
+void
+rb_gc_verify_internal_consistency(void)
+{
+ gc_verify_internal_consistency(rb_gc_get_objspace());
+}
+
+/*
+ * call-seq:
+ * GC.verify_internal_consistency -> nil
+ *
+ * Verify internal consistency.
+ *
+ * This method is implementation specific.
+ * Now this method checks generational consistency
+ * if RGenGC is supported.
+ */
+static VALUE
+gc_verify_internal_consistency_m(VALUE dummy)
+{
+ rb_gc_verify_internal_consistency();
+ return Qnil;
+}
+
+#if GC_CAN_COMPILE_COMPACTION
+/*
+ * call-seq:
+ * GC.auto_compact = flag
+ *
+ * Updates automatic compaction mode.
+ *
+ * When enabled, the compactor will execute on every major collection.
+ *
+ * Enabling compaction will degrade performance on major collections.
+ */
+static VALUE
+gc_set_auto_compact(VALUE _, VALUE v)
+{
+ GC_ASSERT(GC_COMPACTION_SUPPORTED);
+
+ ruby_enable_autocompact = RTEST(v);
+
+#if RGENGC_CHECK_MODE
+ ruby_autocompact_compare_func = NULL;
+
+ if (SYMBOL_P(v)) {
+ ID id = RB_SYM2ID(v);
+ if (id == rb_intern("empty")) {
+ ruby_autocompact_compare_func = compare_free_slots;
+ }
+ }
+#endif
+
+ return v;
+}
+#else
+# define gc_set_auto_compact rb_f_notimplement
+#endif
+
+#if GC_CAN_COMPILE_COMPACTION
+/*
+ * call-seq:
+ * GC.auto_compact -> true or false
+ *
+ * Returns whether or not automatic compaction has been enabled.
+ */
+static VALUE
+gc_get_auto_compact(VALUE _)
+{
+ return ruby_enable_autocompact ? Qtrue : Qfalse;
+}
+#else
+# define gc_get_auto_compact rb_f_notimplement
+#endif
+
+#if GC_CAN_COMPILE_COMPACTION
+/*
+ * call-seq:
+ * GC.latest_compact_info -> hash
+ *
+ * Returns information about object moved in the most recent \GC compaction.
+ *
+ * The returned +hash+ contains the following keys:
+ *
+ * [considered]
+ * Hash containing the type of the object as the key and the number of
+ * objects of that type that were considered for movement.
+ * [moved]
+ * Hash containing the type of the object as the key and the number of
+ * objects of that type that were actually moved.
+ * [moved_up]
+ * Hash containing the type of the object as the key and the number of
+ * objects of that type that were increased in size.
+ * [moved_down]
+ * Hash containing the type of the object as the key and the number of
+ * objects of that type that were decreased in size.
+ *
+ * Some objects can't be moved (due to pinning) so these numbers can be used to
+ * calculate compaction efficiency.
+ */
+static VALUE
+gc_compact_stats(VALUE self)
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+ VALUE h = rb_hash_new();
+ VALUE considered = rb_hash_new();
+ VALUE moved = rb_hash_new();
+ VALUE moved_up = rb_hash_new();
+ VALUE moved_down = rb_hash_new();
+
+ for (size_t i = 0; i < T_MASK; i++) {
+ if (objspace->rcompactor.considered_count_table[i]) {
+ rb_hash_aset(considered, type_sym(i), SIZET2NUM(objspace->rcompactor.considered_count_table[i]));
+ }
+
+ if (objspace->rcompactor.moved_count_table[i]) {
+ rb_hash_aset(moved, type_sym(i), SIZET2NUM(objspace->rcompactor.moved_count_table[i]));
+ }
+
+ if (objspace->rcompactor.moved_up_count_table[i]) {
+ rb_hash_aset(moved_up, type_sym(i), SIZET2NUM(objspace->rcompactor.moved_up_count_table[i]));
+ }
+
+ if (objspace->rcompactor.moved_down_count_table[i]) {
+ rb_hash_aset(moved_down, type_sym(i), SIZET2NUM(objspace->rcompactor.moved_down_count_table[i]));
+ }
+ }
+
+ rb_hash_aset(h, ID2SYM(rb_intern("considered")), considered);
+ rb_hash_aset(h, ID2SYM(rb_intern("moved")), moved);
+ rb_hash_aset(h, ID2SYM(rb_intern("moved_up")), moved_up);
+ rb_hash_aset(h, ID2SYM(rb_intern("moved_down")), moved_down);
+
+ return h;
+}
+#else
+# define gc_compact_stats rb_f_notimplement
+#endif
+
+#if GC_CAN_COMPILE_COMPACTION
+/*
+ * call-seq:
+ * GC.compact -> hash
+ *
+ * This function compacts objects together in Ruby's heap. It eliminates
+ * unused space (or fragmentation) in the heap by moving objects in to that
+ * unused space.
+ *
+ * The returned +hash+ contains statistics about the objects that were moved;
+ * see GC.latest_compact_info.
+ *
+ * This method is only expected to work on CRuby.
+ *
+ * To test whether \GC compaction is supported, use the idiom:
+ *
+ * GC.respond_to?(:compact)
+ */
+static VALUE
+gc_compact(VALUE self)
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+ int full_marking_p = gc_config_full_mark_val;
+ gc_config_full_mark_set(TRUE);
+
+ /* Run GC with compaction enabled */
+ rb_gc_impl_start(rb_gc_get_objspace(), true, true, true, true);
+ gc_config_full_mark_set(full_marking_p);
+
+ return gc_compact_stats(self);
+}
+#else
+# define gc_compact rb_f_notimplement
+#endif
+
+#if GC_CAN_COMPILE_COMPACTION
+struct desired_compaction_pages_i_data {
+ rb_objspace_t *objspace;
+ size_t required_slots[HEAP_COUNT];
+};
+
+static int
+desired_compaction_pages_i(struct heap_page *page, void *data)
+{
+ struct desired_compaction_pages_i_data *tdata = data;
+ rb_objspace_t *objspace = tdata->objspace;
+ VALUE vstart = (VALUE)page->start;
+ VALUE vend = vstart + (VALUE)(page->total_slots * page->heap->slot_size);
+
+
+ for (VALUE v = vstart; v != vend; v += page->heap->slot_size) {
+ asan_unpoisoning_object(v) {
+ /* skip T_NONEs; they won't be moved */
+ if (BUILTIN_TYPE(v) != T_NONE) {
+ rb_heap_t *dest_pool = gc_compact_destination_pool(objspace, page->heap, v);
+ size_t dest_pool_idx = dest_pool - heaps;
+ tdata->required_slots[dest_pool_idx]++;
+ }
+ }
+ }
+
+ return 0;
+}
+
+/* call-seq:
+ * GC.verify_compaction_references(toward: nil, double_heap: false) -> hash
+ *
+ * Verify compaction reference consistency.
+ *
+ * This method is implementation specific. During compaction, objects that
+ * were moved are replaced with T_MOVED objects. No object should have a
+ * reference to a T_MOVED object after compaction.
+ *
+ * This function expands the heap to ensure room to move all objects,
+ * compacts the heap to make sure everything moves, updates all references,
+ * then performs a full \GC. If any object contains a reference to a T_MOVED
+ * object, that object should be pushed on the mark stack, and will
+ * make a SEGV.
+ */
+static VALUE
+gc_verify_compaction_references(int argc, VALUE* argv, VALUE self)
+{
+ static ID keywords[3] = {0};
+ if (!keywords[0]) {
+ keywords[0] = rb_intern("toward");
+ keywords[1] = rb_intern("double_heap");
+ keywords[2] = rb_intern("expand_heap");
+ }
+
+ VALUE options;
+ rb_scan_args_kw(rb_keyword_given_p(), argc, argv, ":", &options);
+
+ VALUE arguments[3] = { Qnil, Qfalse, Qfalse };
+ int kwarg_count = rb_get_kwargs(options, keywords, 0, 3, arguments);
+ bool toward_empty = kwarg_count > 0 && SYMBOL_P(arguments[0]) && SYM2ID(arguments[0]) == rb_intern("empty");
+ bool expand_heap = (kwarg_count > 1 && RTEST(arguments[1])) || (kwarg_count > 2 && RTEST(arguments[2]));
+
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+
+ /* Clear the heap. */
+ rb_gc_impl_start(objspace, true, true, true, false);
+
+ unsigned int lev = RB_GC_VM_LOCK();
+ {
+ gc_rest(objspace);
+
+ /* if both double_heap and expand_heap are set, expand_heap takes precedence */
+ if (expand_heap) {
+ struct desired_compaction_pages_i_data desired_compaction = {
+ .objspace = objspace,
+ .required_slots = {0},
+ };
+ /* Work out how many objects want to be in each size pool, taking account of moves */
+ objspace_each_pages(objspace, desired_compaction_pages_i, &desired_compaction, TRUE);
+
+ /* Find out which pool has the most pages */
+ size_t max_existing_pages = 0;
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ max_existing_pages = MAX(max_existing_pages, heap->total_pages);
+ }
+
+ /* Add pages to each size pool so that compaction is guaranteed to move every object */
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+
+ size_t pages_to_add = 0;
+ /*
+ * Step 1: Make sure every pool has the same number of pages, by adding empty pages
+ * to smaller pools. This is required to make sure the compact cursor can advance
+ * through all of the pools in `gc_sweep_compact` without hitting the "sweep &
+ * compact cursors met" condition on some pools before fully compacting others
+ */
+ pages_to_add += max_existing_pages - heap->total_pages;
+ /*
+ * Step 2: Now add additional free pages to each size pool sufficient to hold all objects
+ * that want to be in that size pool, whether moved into it or moved within it
+ */
+ objspace->heap_pages.allocatable_bytes = desired_compaction.required_slots[i] * heap->slot_size;
+ while (objspace->heap_pages.allocatable_bytes > 0) {
+ heap_page_allocate_and_initialize(objspace, heap);
+ }
+ /*
+ * Step 3: Add two more pages so that the compact & sweep cursors will meet _after_ all objects
+ * have been moved, and not on the last iteration of the `gc_sweep_compact` loop
+ */
+ pages_to_add += 2;
+
+ for (; pages_to_add > 0; pages_to_add--) {
+ heap_page_allocate_and_initialize_force(objspace, heap);
+ }
+ }
+ }
+
+ if (toward_empty) {
+ objspace->rcompactor.compare_func = compare_free_slots;
+ }
+ }
+ RB_GC_VM_UNLOCK(lev);
+
+ rb_gc_impl_start(rb_gc_get_objspace(), true, true, true, true);
+
+ rb_objspace_reachable_objects_from_root(root_obj_check_moved_i, objspace);
+ objspace_each_objects(objspace, heap_check_moved_i, objspace, TRUE);
+
+ objspace->rcompactor.compare_func = NULL;
+
+ return gc_compact_stats(self);
+}
+#else
+# define gc_verify_compaction_references rb_f_notimplement
+#endif
+
+void
+rb_gc_impl_objspace_free(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ if (is_lazy_sweeping(objspace))
+ rb_bug("lazy sweeping underway when freeing object space");
+
+ free(objspace->profile.records);
+ objspace->profile.records = NULL;
+
+ for (size_t i = 0; i < rb_darray_size(objspace->heap_pages.sorted); i++) {
+ heap_page_free(objspace, rb_darray_get(objspace->heap_pages.sorted, i));
+ }
+ rb_darray_free_without_gc(objspace->heap_pages.sorted);
+ heap_pages_lomem = 0;
+ heap_pages_himem = 0;
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+ heap->total_pages = 0;
+ heap->total_slots = 0;
+ }
+
+ free_stack_chunks(&objspace->mark_stack);
+ mark_stack_free_cache(&objspace->mark_stack);
+
+ rb_darray_free_without_gc(objspace->weak_references);
+
+#ifdef MALLOC_COUNTERS_NEED_LOCK
+ rb_native_mutex_destroy(&objspace->malloc_counters.lock);
+#endif
+
+ free(objspace);
+}
+
+#if MALLOC_ALLOCATED_SIZE
+/*
+ * call-seq:
+ * GC.malloc_allocated_size -> Integer
+ *
+ * Returns the size of memory allocated by malloc().
+ *
+ * Only available if ruby was built with +CALC_EXACT_MALLOC_SIZE+.
+ */
+
+static VALUE
+gc_malloc_allocated_size(VALUE self)
+{
+ rb_objspace_t *objspace = (rb_objspace_t *)rb_gc_get_objspace();
+ return ULL2NUM(objspace->malloc_params.allocated_size);
+}
+
+/*
+ * call-seq:
+ * GC.malloc_allocations -> Integer
+ *
+ * Returns the number of malloc() allocations.
+ *
+ * Only available if ruby was built with +CALC_EXACT_MALLOC_SIZE+.
+ */
+
+static VALUE
+gc_malloc_allocations(VALUE self)
+{
+ rb_objspace_t *objspace = (rb_objspace_t *)rb_gc_get_objspace();
+ return ULL2NUM(objspace->malloc_params.allocations);
+}
+#endif
+
+void
+rb_gc_impl_before_fork(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ objspace->fork_vm_lock_lev = RB_GC_VM_LOCK();
+ rb_gc_vm_barrier();
+}
+
+void
+rb_gc_impl_after_fork(void *objspace_ptr, rb_pid_t pid)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ RB_GC_VM_UNLOCK(objspace->fork_vm_lock_lev);
+ objspace->fork_vm_lock_lev = 0;
+
+ if (pid == 0) { /* child process */
+ rb_gc_ractor_newobj_cache_foreach(gc_ractor_newobj_cache_clear, NULL);
+ }
+}
+
+VALUE rb_ident_hash_new_with_size(st_index_t size);
+
+#if GC_DEBUG_STRESS_TO_CLASS
+/*
+ * call-seq:
+ * GC.add_stress_to_class(class[, ...])
+ *
+ * Raises NoMemoryError when allocating an instance of the given classes.
+ *
+ */
+static VALUE
+rb_gcdebug_add_stress_to_class(int argc, VALUE *argv, VALUE self)
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+
+ if (!stress_to_class) {
+ set_stress_to_class(rb_ident_hash_new_with_size(argc));
+ }
+
+ for (int i = 0; i < argc; i++) {
+ VALUE klass = argv[i];
+ rb_hash_aset(stress_to_class, klass, Qtrue);
+ }
+
+ return self;
+}
+
+/*
+ * call-seq:
+ * GC.remove_stress_to_class(class[, ...])
+ *
+ * No longer raises NoMemoryError when allocating an instance of the
+ * given classes.
+ *
+ */
+static VALUE
+rb_gcdebug_remove_stress_to_class(int argc, VALUE *argv, VALUE self)
+{
+ rb_objspace_t *objspace = rb_gc_get_objspace();
+
+ if (stress_to_class) {
+ for (int i = 0; i < argc; ++i) {
+ rb_hash_delete(stress_to_class, argv[i]);
+ }
+
+ if (rb_hash_size(stress_to_class) == 0) {
+ stress_to_class = 0;
+ }
+ }
+
+ return Qnil;
+}
+#endif
+
+void *
+rb_gc_impl_objspace_alloc(void)
+{
+ rb_objspace_t *objspace = calloc1(sizeof(rb_objspace_t));
+
+ return objspace;
+}
+
+void
+rb_gc_impl_objspace_init(void *objspace_ptr)
+{
+ rb_objspace_t *objspace = objspace_ptr;
+
+ gc_config_full_mark_set(TRUE);
+
+ objspace->flags.measure_gc = true;
+ malloc_limit = gc_params.malloc_limit_min;
+#ifdef MALLOC_COUNTERS_NEED_LOCK
+ rb_native_mutex_initialize(&objspace->malloc_counters.lock);
+#endif
+ objspace->finalize_deferred_pjob = rb_postponed_job_preregister(0, gc_finalize_deferred, objspace);
+ if (objspace->finalize_deferred_pjob == POSTPONED_JOB_HANDLE_INVALID) {
+ rb_bug("Could not preregister postponed job for GC");
+ }
+
+ /* A standard RVALUE (RBasic + embedded VALUEs + debug overhead) must fit
+ * in at least one pool. In debug builds RVALUE_OVERHEAD can push this
+ * beyond the 48-byte pool into the 64-byte pool, which is fine. */
+ GC_ASSERT(rb_gc_impl_size_allocatable_p(sizeof(struct RBasic) + sizeof(VALUE[RBIMPL_RVALUE_EMBED_LEN_MAX])));
+
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ rb_heap_t *heap = &heaps[i];
+
+ heap->slot_size = pool_slot_sizes[i];
+
+ ccan_list_head_init(&heap->pages);
+ }
+
+ init_size_to_heap_idx();
+
+ rb_darray_make_without_gc(&objspace->heap_pages.sorted, 0);
+ rb_darray_make_without_gc(&objspace->weak_references, 0);
+
+#if defined(INIT_HEAP_PAGE_ALLOC_USE_MMAP)
+ /* Need to determine if we can use mmap at runtime. */
+ heap_page_alloc_use_mmap = INIT_HEAP_PAGE_ALLOC_USE_MMAP;
+#endif
+#if RGENGC_ESTIMATE_OLDMALLOC
+ objspace->rgengc.oldmalloc_increase_limit = gc_params.oldmalloc_limit_min;
+#endif
+ gc_params.heap_init_bytes = GC_HEAP_INIT_BYTES;
+
+ init_mark_stack(&objspace->mark_stack);
+
+ objspace->profile.invoke_time = getrusage_time();
+ finalizer_table = st_init_numtable();
+}
+
+void
+rb_gc_impl_init(void)
+{
+ VALUE gc_constants = rb_hash_new();
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("DEBUG")), GC_DEBUG ? Qtrue : Qfalse);
+ /* Minimum slot size that fits a standard RVALUE */
+ size_t rvalue_pool = 0;
+ for (size_t i = 0; i < HEAP_COUNT; i++) {
+ if (pool_slot_sizes[i] >= RVALUE_SLOT_SIZE) { rvalue_pool = pool_slot_sizes[i]; break; }
+ }
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVALUE_SIZE")), SIZET2NUM(rvalue_pool - RVALUE_OVERHEAD));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RBASIC_SIZE")), SIZET2NUM(sizeof(struct RBasic)));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVALUE_OVERHEAD")), SIZET2NUM(RVALUE_OVERHEAD));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("HEAP_PAGE_BITMAP_SIZE")), SIZET2NUM(HEAP_PAGE_BITMAP_SIZE));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("HEAP_PAGE_SIZE")), SIZET2NUM(HEAP_PAGE_SIZE));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("HEAP_COUNT")), LONG2FIX(HEAP_COUNT));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVARGC_MAX_ALLOCATE_SIZE")), LONG2FIX(heap_slot_size(HEAP_COUNT - 1)));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVALUE_OLD_AGE")), LONG2FIX(RVALUE_OLD_AGE));
+ if (RB_BUG_INSTEAD_OF_RB_MEMERROR+0) {
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RB_BUG_INSTEAD_OF_RB_MEMERROR")), Qtrue);
+ }
+ OBJ_FREEZE(gc_constants);
+ /* Internal constants in the garbage collector. */
+ rb_define_const(rb_mGC, "INTERNAL_CONSTANTS", gc_constants);
+
+ if (GC_COMPACTION_SUPPORTED) {
+ rb_define_singleton_method(rb_mGC, "compact", gc_compact, 0);
+ rb_define_singleton_method(rb_mGC, "auto_compact", gc_get_auto_compact, 0);
+ rb_define_singleton_method(rb_mGC, "auto_compact=", gc_set_auto_compact, 1);
+ rb_define_singleton_method(rb_mGC, "latest_compact_info", gc_compact_stats, 0);
+ rb_define_singleton_method(rb_mGC, "verify_compaction_references", gc_verify_compaction_references, -1);
+ }
+ else {
+ rb_define_singleton_method(rb_mGC, "compact", rb_f_notimplement, 0);
+ rb_define_singleton_method(rb_mGC, "auto_compact", rb_f_notimplement, 0);
+ rb_define_singleton_method(rb_mGC, "auto_compact=", rb_f_notimplement, 1);
+ rb_define_singleton_method(rb_mGC, "latest_compact_info", rb_f_notimplement, 0);
+ rb_define_singleton_method(rb_mGC, "verify_compaction_references", rb_f_notimplement, -1);
+ }
+
+#if GC_DEBUG_STRESS_TO_CLASS
+ rb_define_singleton_method(rb_mGC, "add_stress_to_class", rb_gcdebug_add_stress_to_class, -1);
+ rb_define_singleton_method(rb_mGC, "remove_stress_to_class", rb_gcdebug_remove_stress_to_class, -1);
+#endif
+
+ /* internal methods */
+ rb_define_singleton_method(rb_mGC, "verify_internal_consistency", gc_verify_internal_consistency_m, 0);
+
+#if MALLOC_ALLOCATED_SIZE
+ rb_define_singleton_method(rb_mGC, "malloc_allocated_size", gc_malloc_allocated_size, 0);
+ rb_define_singleton_method(rb_mGC, "malloc_allocations", gc_malloc_allocations, 0);
+#endif
+
+ VALUE rb_mProfiler = rb_define_module_under(rb_mGC, "Profiler");
+ rb_define_singleton_method(rb_mProfiler, "enabled?", gc_profile_enable_get, 0);
+ rb_define_singleton_method(rb_mProfiler, "enable", gc_profile_enable, 0);
+ rb_define_singleton_method(rb_mProfiler, "raw_data", gc_profile_record_get, 0);
+ rb_define_singleton_method(rb_mProfiler, "disable", gc_profile_disable, 0);
+ rb_define_singleton_method(rb_mProfiler, "clear", gc_profile_clear, 0);
+ rb_define_singleton_method(rb_mProfiler, "result", gc_profile_result, 0);
+ rb_define_singleton_method(rb_mProfiler, "report", gc_profile_report, -1);
+ rb_define_singleton_method(rb_mProfiler, "total_time", gc_profile_total_time, 0);
+
+ {
+ VALUE opts;
+ /* \GC build options */
+ rb_define_const(rb_mGC, "OPTS", opts = rb_ary_new());
+#define OPT(o) if (o) rb_ary_push(opts, rb_interned_str(#o, sizeof(#o) - 1))
+ OPT(GC_DEBUG);
+ OPT(USE_RGENGC);
+ OPT(RGENGC_DEBUG);
+ OPT(RGENGC_CHECK_MODE);
+ OPT(RGENGC_PROFILE);
+ OPT(RGENGC_ESTIMATE_OLDMALLOC);
+ OPT(GC_PROFILE_MORE_DETAIL);
+ OPT(GC_ENABLE_LAZY_SWEEP);
+ OPT(CALC_EXACT_MALLOC_SIZE);
+ OPT(MALLOC_ALLOCATED_SIZE);
+ OPT(MALLOC_ALLOCATED_SIZE_CHECK);
+ OPT(GC_PROFILE_DETAIL_MEMORY);
+ OPT(GC_COMPACTION_SUPPORTED);
+#undef OPT
+ OBJ_FREEZE(opts);
+ }
+}
diff --git a/gc/default/extconf.rb b/gc/default/extconf.rb
new file mode 100644
index 0000000000..2940a4c962
--- /dev/null
+++ b/gc/default/extconf.rb
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+require_relative "../extconf_base"
+
+create_gc_makefile("default")
diff --git a/gc/extconf_base.rb b/gc/extconf_base.rb
new file mode 100644
index 0000000000..2a224b9b0e
--- /dev/null
+++ b/gc/extconf_base.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+require "mkmf"
+
+srcdir = File.join(__dir__, "..")
+$INCFLAGS << " -I#{srcdir}"
+
+$CPPFLAGS << " -DBUILDING_MODULAR_GC"
+
+append_cflags("-fPIC")
+
+def create_gc_makefile(name, &block)
+ create_makefile("librubygc.#{name}", &block)
+end
diff --git a/gc/gc.h b/gc/gc.h
new file mode 100644
index 0000000000..ea8056c671
--- /dev/null
+++ b/gc/gc.h
@@ -0,0 +1,291 @@
+#ifndef GC_GC_H
+#define GC_GC_H
+/**
+ * @author Ruby developers <ruby-core@ruby-lang.org>
+ * @copyright This file is a part of the programming language Ruby.
+ * Permission is hereby granted, to either redistribute and/or
+ * modify this file, provided that the conditions mentioned in the
+ * file COPYING are met. Consult the file for details.
+ * @brief Private header for the default GC and other GC implementations
+ * first introduced for [Feature #20470].
+ */
+#include "ruby/ruby.h"
+#include "ruby/assert.h"
+
+#include "ruby/thread_native.h"
+
+#ifndef VM_CHECK_MODE
+# define VM_CHECK_MODE RUBY_DEBUG
+#endif
+
+// From ractor_core.h
+#ifndef RACTOR_CHECK_MODE
+# define RACTOR_CHECK_MODE (VM_CHECK_MODE || RUBY_DEBUG) && (SIZEOF_UINT64_T == SIZEOF_VALUE)
+#endif
+
+#if RACTOR_CHECK_MODE
+void rb_ractor_setup_belonging(VALUE obj);
+
+struct rb_gc_obj_suffix {
+ uint32_t _ractor_belonging_id;
+};
+
+# define RB_GC_OBJ_HAS_SUFFIX 1
+# define RB_GC_OBJ_SUFFIX_SIZE (sizeof(struct rb_gc_obj_suffix))
+#else
+# define RB_GC_OBJ_HAS_SUFFIX 0
+# define RB_GC_OBJ_SUFFIX_SIZE 0
+#endif
+
+struct rb_gc_vm_context {
+ rb_nativethread_lock_t lock;
+
+ struct rb_execution_context_struct *ec;
+};
+
+typedef int (*vm_table_foreach_callback_func)(VALUE value, void *data);
+typedef int (*vm_table_update_callback_func)(VALUE *value, void *data);
+
+enum rb_gc_vm_weak_tables {
+ RB_GC_VM_CI_TABLE,
+ RB_GC_VM_OVERLOADED_CME_TABLE,
+ RB_GC_VM_GLOBAL_SYMBOLS_TABLE,
+ RB_GC_VM_ID2REF_TABLE,
+ RB_GC_VM_GENERIC_FIELDS_TABLE,
+ RB_GC_VM_FROZEN_STRINGS_TABLE,
+ RB_GC_VM_WEAK_TABLE_COUNT
+};
+
+#define RB_GC_VM_LOCK() rb_gc_vm_lock(__FILE__, __LINE__)
+#define RB_GC_VM_UNLOCK(lev) rb_gc_vm_unlock(lev, __FILE__, __LINE__)
+#define RB_GC_CR_LOCK() rb_gc_cr_lock(__FILE__, __LINE__)
+#define RB_GC_CR_UNLOCK(lev) rb_gc_cr_unlock(lev, __FILE__, __LINE__)
+#define RB_GC_VM_LOCK_NO_BARRIER() rb_gc_vm_lock_no_barrier(__FILE__, __LINE__)
+#define RB_GC_VM_UNLOCK_NO_BARRIER(lev) rb_gc_vm_unlock_no_barrier(lev, __FILE__, __LINE__)
+
+#if USE_MODULAR_GC
+# define MODULAR_GC_FN
+#else
+// This takes advantage of internal linkage winning when appearing first.
+// See C99 6.2.2p4.
+# define MODULAR_GC_FN static
+#endif
+
+#if USE_MODULAR_GC
+RUBY_SYMBOL_EXPORT_BEGIN
+#endif
+
+// These functions cannot be defined as static because they are used by other
+// files in Ruby.
+size_t rb_size_mul_or_raise(size_t x, size_t y, VALUE exc);
+void rb_objspace_reachable_objects_from(VALUE obj, void (func)(VALUE, void *), void *data);
+const char *rb_raw_obj_info(char *const buff, const size_t buff_size, VALUE obj);
+const char *rb_obj_info(VALUE obj);
+size_t rb_obj_memsize_of(VALUE obj);
+bool ruby_free_at_exit_p(void);
+void rb_objspace_reachable_objects_from_root(void (func)(const char *category, VALUE, void *), void *passing_data);
+void rb_gc_verify_shareable(VALUE);
+
+MODULAR_GC_FN unsigned int rb_gc_vm_lock(const char *file, int line);
+MODULAR_GC_FN void rb_gc_vm_unlock(unsigned int lev, const char *file, int line);
+MODULAR_GC_FN unsigned int rb_gc_cr_lock(const char *file, int line);
+MODULAR_GC_FN void rb_gc_cr_unlock(unsigned int lev, const char *file, int line);
+MODULAR_GC_FN unsigned int rb_gc_vm_lock_no_barrier(const char *file, int line);
+MODULAR_GC_FN void rb_gc_vm_unlock_no_barrier(unsigned int lev, const char *file, int line);
+MODULAR_GC_FN void rb_gc_vm_barrier(void);
+MODULAR_GC_FN size_t rb_gc_obj_optimal_size(VALUE obj);
+MODULAR_GC_FN void rb_gc_mark_children(void *objspace, VALUE obj);
+MODULAR_GC_FN void rb_gc_vm_weak_table_foreach(vm_table_foreach_callback_func callback, vm_table_update_callback_func update_callback, void *data, bool weak_only, enum rb_gc_vm_weak_tables table);
+MODULAR_GC_FN void rb_gc_update_object_references(void *objspace, VALUE obj);
+MODULAR_GC_FN void rb_gc_update_vm_references(void *objspace);
+MODULAR_GC_FN void rb_gc_event_hook(VALUE obj, rb_event_flag_t event);
+MODULAR_GC_FN void *rb_gc_get_objspace(void);
+MODULAR_GC_FN void rb_gc_run_obj_finalizer(VALUE objid, long count, VALUE (*callback)(long i, void *data), void *data);
+MODULAR_GC_FN void rb_gc_set_pending_interrupt(void);
+MODULAR_GC_FN void rb_gc_unset_pending_interrupt(void);
+MODULAR_GC_FN void rb_gc_obj_free_vm_weak_references(VALUE obj);
+MODULAR_GC_FN bool rb_gc_obj_free(void *objspace, VALUE obj);
+MODULAR_GC_FN void rb_gc_save_machine_context(void);
+MODULAR_GC_FN void rb_gc_mark_roots(void *objspace, const char **categoryp);
+MODULAR_GC_FN void rb_gc_ractor_newobj_cache_foreach(void (*func)(void *cache, void *data), void *data);
+MODULAR_GC_FN bool rb_gc_multi_ractor_p(void);
+MODULAR_GC_FN bool rb_gc_shutdown_call_finalizer_p(VALUE obj);
+MODULAR_GC_FN void rb_gc_obj_changed_pool(VALUE obj, size_t heap_id);
+MODULAR_GC_FN void rb_gc_prepare_heap_process_object(VALUE obj);
+MODULAR_GC_FN bool rb_memerror_reentered(void);
+MODULAR_GC_FN bool rb_obj_id_p(VALUE);
+MODULAR_GC_FN void rb_gc_before_updating_jit_code(void);
+MODULAR_GC_FN void rb_gc_after_updating_jit_code(void);
+MODULAR_GC_FN bool rb_gc_obj_shareable_p(VALUE);
+MODULAR_GC_FN void rb_gc_rp(VALUE);
+MODULAR_GC_FN void rb_gc_handle_weak_references(VALUE obj);
+MODULAR_GC_FN bool rb_gc_obj_needs_cleanup_p(VALUE obj);
+
+#if USE_MODULAR_GC
+MODULAR_GC_FN bool rb_gc_event_hook_required_p(rb_event_flag_t event);
+MODULAR_GC_FN void *rb_gc_get_ractor_newobj_cache(void);
+MODULAR_GC_FN void rb_gc_initialize_vm_context(struct rb_gc_vm_context *context);
+MODULAR_GC_FN void rb_gc_move_obj_during_marking(VALUE from, VALUE to);
+MODULAR_GC_FN void rb_gc_print_backtrace();
+#endif
+
+#if USE_MODULAR_GC
+RUBY_SYMBOL_EXPORT_END
+#endif
+
+void rb_ractor_finish_marking(void);
+
+// -------------------Private section begin------------------------
+// Functions in this section are private to the default GC and gc.c
+
+#ifdef BUILDING_MODULAR_GC
+RBIMPL_WARNING_PUSH()
+RBIMPL_WARNING_IGNORED(-Wunused-function)
+#endif
+
+/* RGENGC_CHECK_MODE
+ * 0: disable all assertions
+ * 1: enable assertions (to debug RGenGC)
+ * 2: enable internal consistency check at each GC (for debugging)
+ * 3: enable internal consistency check at each GC steps (for debugging)
+ * 4: enable liveness check
+ * 5: show all references
+ */
+#ifndef RGENGC_CHECK_MODE
+# define RGENGC_CHECK_MODE 0
+#endif
+
+#ifndef GC_ASSERT
+# define GC_ASSERT(expr, ...) RUBY_ASSERT_MESG_WHEN(RGENGC_CHECK_MODE > 0, expr, #expr RBIMPL_VA_OPT_ARGS(__VA_ARGS__))
+#endif
+
+static int
+hash_foreach_replace_value(st_data_t key, st_data_t value, st_data_t argp, int error)
+{
+ if (rb_gc_location((VALUE)value) != (VALUE)value) {
+ return ST_REPLACE;
+ }
+ return ST_CONTINUE;
+}
+
+static int
+hash_replace_ref_value(st_data_t *key, st_data_t *value, st_data_t argp, int existing)
+{
+ *value = rb_gc_location((VALUE)*value);
+
+ return ST_CONTINUE;
+}
+
+static void
+gc_ref_update_table_values_only(st_table *tbl)
+{
+ if (!tbl || tbl->num_entries == 0) return;
+
+ if (st_foreach_with_replace(tbl, hash_foreach_replace_value, hash_replace_ref_value, 0)) {
+ rb_raise(rb_eRuntimeError, "hash modified during iteration");
+ }
+}
+
+static int
+gc_mark_tbl_no_pin_i(st_data_t key, st_data_t value, st_data_t data)
+{
+ rb_gc_mark_movable((VALUE)value);
+
+ return ST_CONTINUE;
+}
+
+static int
+gc_mark_set_no_pin_i(st_data_t key, st_data_t value, st_data_t data)
+{
+ rb_gc_mark_movable((VALUE)key);
+
+ return ST_CONTINUE;
+}
+
+static int
+hash_foreach_replace(st_data_t key, st_data_t value, st_data_t argp, int error)
+{
+ if (rb_gc_location((VALUE)key) != (VALUE)key) {
+ return ST_REPLACE;
+ }
+
+ if (rb_gc_location((VALUE)value) != (VALUE)value) {
+ return ST_REPLACE;
+ }
+
+ return ST_CONTINUE;
+}
+
+static int
+hash_replace_ref(st_data_t *key, st_data_t *value, st_data_t argp, int existing)
+{
+ if (rb_gc_location((VALUE)*key) != (VALUE)*key) {
+ *key = rb_gc_location((VALUE)*key);
+ }
+
+ if (rb_gc_location((VALUE)*value) != (VALUE)*value) {
+ *value = rb_gc_location((VALUE)*value);
+ }
+
+ return ST_CONTINUE;
+}
+
+static void
+gc_update_table_refs(st_table *tbl)
+{
+ if (!tbl || tbl->num_entries == 0) return;
+
+ if (st_foreach_with_replace(tbl, hash_foreach_replace, hash_replace_ref, 0)) {
+ rb_raise(rb_eRuntimeError, "hash modified during iteration");
+ }
+}
+
+static inline size_t
+xmalloc2_size(const size_t count, const size_t elsize)
+{
+ return rb_size_mul_or_raise(count, elsize, rb_eArgError);
+}
+
+static VALUE
+type_sym(size_t type)
+{
+ switch (type) {
+#define COUNT_TYPE(t) case (t): return ID2SYM(rb_intern(#t)); break;
+ COUNT_TYPE(T_NONE);
+ COUNT_TYPE(T_OBJECT);
+ COUNT_TYPE(T_CLASS);
+ COUNT_TYPE(T_MODULE);
+ COUNT_TYPE(T_FLOAT);
+ COUNT_TYPE(T_STRING);
+ COUNT_TYPE(T_REGEXP);
+ COUNT_TYPE(T_ARRAY);
+ COUNT_TYPE(T_HASH);
+ COUNT_TYPE(T_STRUCT);
+ COUNT_TYPE(T_BIGNUM);
+ COUNT_TYPE(T_FILE);
+ COUNT_TYPE(T_DATA);
+ COUNT_TYPE(T_MATCH);
+ COUNT_TYPE(T_COMPLEX);
+ COUNT_TYPE(T_RATIONAL);
+ COUNT_TYPE(T_NIL);
+ COUNT_TYPE(T_TRUE);
+ COUNT_TYPE(T_FALSE);
+ COUNT_TYPE(T_SYMBOL);
+ COUNT_TYPE(T_FIXNUM);
+ COUNT_TYPE(T_IMEMO);
+ COUNT_TYPE(T_UNDEF);
+ COUNT_TYPE(T_NODE);
+ COUNT_TYPE(T_ICLASS);
+ COUNT_TYPE(T_ZOMBIE);
+ COUNT_TYPE(T_MOVED);
+#undef COUNT_TYPE
+ default: return SIZET2NUM(type); break;
+ }
+}
+
+#ifdef BUILDING_MODULAR_GC
+RBIMPL_WARNING_POP()
+#endif
+// -------------------Private section end------------------------
+
+#endif
diff --git a/gc/gc_impl.h b/gc/gc_impl.h
new file mode 100644
index 0000000000..d9e44cc66d
--- /dev/null
+++ b/gc/gc_impl.h
@@ -0,0 +1,127 @@
+#ifndef GC_GC_IMPL_H
+#define GC_GC_IMPL_H
+/**
+ * @author Ruby developers <ruby-core@ruby-lang.org>
+ * @copyright This file is a part of the programming language Ruby.
+ * Permission is hereby granted, to either redistribute and/or
+ * modify this file, provided that the conditions mentioned in the
+ * file COPYING are met. Consult the file for details.
+ * @brief Header for GC implementations introduced in [Feature #20470].
+ */
+#include "ruby/ruby.h"
+
+#ifndef RB_GC_OBJECT_METADATA_ENTRY_DEFINED
+# define RB_GC_OBJECT_METADATA_ENTRY_DEFINED
+struct rb_gc_object_metadata_entry {
+ ID name;
+ VALUE val;
+};
+#endif
+
+#ifdef BUILDING_MODULAR_GC
+# define GC_IMPL_FN
+#else
+// `GC_IMPL_FN` is an implementation detail of `!USE_MODULAR_GC` builds
+// to have the default GC in the same translation unit as gc.c for
+// the sake of optimizer visibility. It expands to nothing unless
+// you're the default GC.
+//
+// For the default GC, do not copy-paste this when implementing
+// these functions. This takes advantage of internal linkage winning
+// when appearing first. See C99 6.2.2p4.
+# define GC_IMPL_FN static
+#endif
+
+// Bootup
+GC_IMPL_FN void *rb_gc_impl_objspace_alloc(void);
+GC_IMPL_FN void rb_gc_impl_objspace_init(void *objspace_ptr);
+GC_IMPL_FN void *rb_gc_impl_ractor_cache_alloc(void *objspace_ptr, void *ractor);
+GC_IMPL_FN void rb_gc_impl_set_params(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_init(void);
+GC_IMPL_FN size_t *rb_gc_impl_heap_sizes(void *objspace_ptr);
+// Shutdown
+GC_IMPL_FN void rb_gc_impl_shutdown_free_objects(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_objspace_free(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_ractor_cache_free(void *objspace_ptr, void *cache);
+// GC
+GC_IMPL_FN void rb_gc_impl_start(void *objspace_ptr, bool full_mark, bool immediate_mark, bool immediate_sweep, bool compact);
+GC_IMPL_FN bool rb_gc_impl_during_gc_p(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_prepare_heap(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_gc_enable(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_gc_disable(void *objspace_ptr, bool finish_current_gc);
+GC_IMPL_FN bool rb_gc_impl_gc_enabled_p(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_stress_set(void *objspace_ptr, VALUE flag);
+GC_IMPL_FN VALUE rb_gc_impl_stress_get(void *objspace_ptr);
+GC_IMPL_FN VALUE rb_gc_impl_config_get(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_config_set(void *objspace_ptr, VALUE hash);
+GC_IMPL_FN struct rb_gc_vm_context *rb_gc_impl_get_vm_context(void *objspace_ptr);
+// Object allocation
+GC_IMPL_FN VALUE rb_gc_impl_new_obj(void *objspace_ptr, void *cache_ptr, VALUE klass, VALUE flags, bool wb_protected, size_t alloc_size);
+GC_IMPL_FN size_t rb_gc_impl_obj_slot_size(VALUE obj);
+GC_IMPL_FN size_t rb_gc_impl_heap_id_for_size(void *objspace_ptr, size_t size);
+GC_IMPL_FN bool rb_gc_impl_size_allocatable_p(size_t size);
+// Malloc
+/*
+ * BEWARE: These functions may or may not run under GVL.
+ *
+ * You might want to make them thread-safe.
+ * Garbage collecting inside is possible if and only if you
+ * already have GVL. Also raising exceptions without one is a
+ * total disaster.
+ *
+ * When you absolutely cannot allocate the requested amount of
+ * memory just return NULL (with appropriate errno set).
+ * The caller side takes care of that situation.
+ */
+GC_IMPL_FN void *rb_gc_impl_malloc(void *objspace_ptr, size_t size, bool gc_allowed);
+GC_IMPL_FN void *rb_gc_impl_calloc(void *objspace_ptr, size_t size, bool gc_allowed);
+GC_IMPL_FN void *rb_gc_impl_realloc(void *objspace_ptr, void *ptr, size_t new_size, size_t old_size, bool gc_allowed);
+GC_IMPL_FN void rb_gc_impl_free(void *objspace_ptr, void *ptr, size_t old_size);
+GC_IMPL_FN void rb_gc_impl_adjust_memory_usage(void *objspace_ptr, ssize_t diff);
+// Marking
+GC_IMPL_FN void rb_gc_impl_mark(void *objspace_ptr, VALUE obj);
+GC_IMPL_FN void rb_gc_impl_mark_and_move(void *objspace_ptr, VALUE *ptr);
+GC_IMPL_FN void rb_gc_impl_mark_and_pin(void *objspace_ptr, VALUE obj);
+GC_IMPL_FN void rb_gc_impl_mark_maybe(void *objspace_ptr, VALUE obj);
+// Weak references
+GC_IMPL_FN void rb_gc_impl_declare_weak_references(void *objspace_ptr, VALUE obj);
+GC_IMPL_FN bool rb_gc_impl_handle_weak_references_alive_p(void *objspace_ptr, VALUE obj);
+// Compaction
+GC_IMPL_FN void rb_gc_impl_register_pinning_obj(void *objspace_ptr, VALUE obj);
+GC_IMPL_FN bool rb_gc_impl_object_moved_p(void *objspace_ptr, VALUE obj);
+GC_IMPL_FN VALUE rb_gc_impl_location(void *objspace_ptr, VALUE value);
+// Write barriers
+GC_IMPL_FN void rb_gc_impl_writebarrier(void *objspace_ptr, VALUE a, VALUE b);
+GC_IMPL_FN void rb_gc_impl_writebarrier_unprotect(void *objspace_ptr, VALUE obj);
+GC_IMPL_FN void rb_gc_impl_writebarrier_remember(void *objspace_ptr, VALUE obj);
+// Heap walking
+GC_IMPL_FN void rb_gc_impl_each_objects(void *objspace_ptr, int (*callback)(void *, void *, size_t, void *), void *data);
+GC_IMPL_FN void rb_gc_impl_each_object(void *objspace_ptr, void (*func)(VALUE obj, void *data), void *data);
+// Finalizers
+GC_IMPL_FN void rb_gc_impl_make_zombie(void *objspace_ptr, VALUE obj, void (*dfree)(void *), void *data);
+GC_IMPL_FN VALUE rb_gc_impl_define_finalizer(void *objspace_ptr, VALUE obj, VALUE block);
+GC_IMPL_FN void rb_gc_impl_undefine_finalizer(void *objspace_ptr, VALUE obj);
+GC_IMPL_FN void rb_gc_impl_copy_finalizer(void *objspace_ptr, VALUE dest, VALUE obj);
+GC_IMPL_FN void rb_gc_impl_shutdown_call_finalizer(void *objspace_ptr);
+// Forking
+GC_IMPL_FN void rb_gc_impl_before_fork(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_after_fork(void *objspace_ptr, rb_pid_t pid);
+// Statistics
+GC_IMPL_FN void rb_gc_impl_set_measure_total_time(void *objspace_ptr, VALUE flag);
+GC_IMPL_FN bool rb_gc_impl_get_measure_total_time(void *objspace_ptr);
+GC_IMPL_FN unsigned long long rb_gc_impl_get_total_time(void *objspace_ptr);
+GC_IMPL_FN size_t rb_gc_impl_gc_count(void *objspace_ptr);
+GC_IMPL_FN VALUE rb_gc_impl_latest_gc_info(void *objspace_ptr, VALUE key);
+GC_IMPL_FN VALUE rb_gc_impl_stat(void *objspace_ptr, VALUE hash_or_sym);
+GC_IMPL_FN VALUE rb_gc_impl_stat_heap(void *objspace_ptr, VALUE heap_name, VALUE hash_or_sym);
+GC_IMPL_FN const char *rb_gc_impl_active_gc_name(void);
+// Miscellaneous
+GC_IMPL_FN struct rb_gc_object_metadata_entry *rb_gc_impl_object_metadata(void *objspace_ptr, VALUE obj);
+GC_IMPL_FN bool rb_gc_impl_pointer_to_heap_p(void *objspace_ptr, const void *ptr);
+GC_IMPL_FN bool rb_gc_impl_garbage_object_p(void *objspace_ptr, VALUE obj);
+GC_IMPL_FN void rb_gc_impl_set_event_hook(void *objspace_ptr, const rb_event_flag_t event);
+GC_IMPL_FN void rb_gc_impl_copy_attributes(void *objspace_ptr, VALUE dest, VALUE obj);
+
+#undef GC_IMPL_FN
+
+#endif
diff --git a/gc/mmtk/.gitignore b/gc/mmtk/.gitignore
new file mode 100644
index 0000000000..eb5a316cbd
--- /dev/null
+++ b/gc/mmtk/.gitignore
@@ -0,0 +1 @@
+target
diff --git a/gc/mmtk/Cargo.lock b/gc/mmtk/Cargo.lock
new file mode 100644
index 0000000000..910048fa80
--- /dev/null
+++ b/gc/mmtk/Cargo.lock
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+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+
+[[package]]
+name = "wit-bindgen-rt"
+version = "0.39.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f42320e61fe2cfd34354ecb597f86f413484a798ba44a8ca1165c58d42da6c1"
+dependencies = [
+ "bitflags",
+]
diff --git a/gc/mmtk/Cargo.toml b/gc/mmtk/Cargo.toml
new file mode 100644
index 0000000000..d856122900
--- /dev/null
+++ b/gc/mmtk/Cargo.toml
@@ -0,0 +1,42 @@
+[package]
+name = "mmtk_ruby"
+version = "0.1.0"
+authors = []
+edition = "2021"
+
+[lib]
+name = "mmtk_ruby"
+crate-type = ["cdylib", "staticlib"]
+
+[profile.release]
+lto = true
+
+[dependencies]
+libc = "0.2"
+log = "0.4.14"
+env_logger = "0.11.3"
+once_cell = "1.17.0"
+atomic_refcell = "0.1.9"
+probe = "0.5"
+sysinfo = "0.32.0"
+
+[dependencies.mmtk]
+features = ["is_mmtk_object", "object_pinning", "sticky_immix_non_moving_nursery"]
+
+# Uncomment the following lines to use mmtk-core from the official repository.
+git = "https://github.com/mmtk/mmtk-core.git"
+rev = "c6317a3f1c262e33fc2e427e4cc999c17bcc4791"
+
+# Uncomment the following line to use mmtk-core from a local repository.
+# path = "../../../mmtk-core"
+
+[features]
+default = []
+
+# When moving an object, clear its original copy.
+clear_old_copy = []
+
+# Enable extra assertions in release build. For debugging.
+extra_assert = []
+
+[workspace]
diff --git a/gc/mmtk/cbindgen.toml b/gc/mmtk/cbindgen.toml
new file mode 100644
index 0000000000..b99c30efc8
--- /dev/null
+++ b/gc/mmtk/cbindgen.toml
@@ -0,0 +1,36 @@
+language = "C"
+
+include_guard = "MMTK_H"
+
+autogen_warning = "/* Warning, this file is autogenerated by cbindgen from the mmtk-ruby repository. Don't modify this manually. */"
+
+tab_width = 4
+
+usize_is_size_t = true
+
+after_includes = """
+
+typedef struct MMTk_Builder MMTk_Builder;
+typedef struct MMTk_Mutator MMTk_Mutator;
+
+typedef struct MMTk_ractor_cache *MMTk_VMThread;
+typedef struct MMTk_ractor_cache *MMTk_VMMutatorThread;
+typedef struct MMTk_GCThreadTLS *MMTk_VMWorkerThread;
+typedef void *MMTk_Address;
+typedef void *MMTk_ObjectReference;
+typedef void *MMTk_NullableObjectReference;
+typedef uint32_t MMTk_AllocationSemantics;
+
+typedef struct MMTk_BumpPointer {
+ uintptr_t cursor;
+ uintptr_t limit;
+} MMTk_BumpPointer;
+"""
+
+[export]
+exclude = ["RubyMutator"]
+prefix = "MMTk_"
+
+[export.rename]
+"MMTKBuilder" = "Builder"
+"RubyMutator" = "Mutator"
diff --git a/gc/mmtk/depend b/gc/mmtk/depend
new file mode 100644
index 0000000000..77b229af36
--- /dev/null
+++ b/gc/mmtk/depend
@@ -0,0 +1,18 @@
+$(TARGET_SO): $(MMTK_BUILD)/$(LIBMMTK_RUBY)
+
+# Add the `libmmtk_ruby.a` target to run `cargo build`
+
+release/$(LIBMMTK_RUBY) debug/$(LIBMMTK_RUBY): $(RUSTSRCS) $(srcdir)/Cargo.toml $(srcdir)/Cargo.toml
+
+release/$(LIBMMTK_RUBY):
+ CARGO_TARGET_DIR="." cargo build --manifest-path=$(srcdir)/Cargo.toml --release
+
+debug/$(LIBMMTK_RUBY):
+ CARGO_TARGET_DIR="." cargo build --manifest-path=$(srcdir)/Cargo.toml
+
+clean: clean-mmtk
+
+.PHONY: clean-mmtk
+clean-mmtk:
+ -$(Q)$(RM_RF) debug release
+ -$(Q)$(RM) .rustc_info.json
diff --git a/gc/mmtk/extconf.rb b/gc/mmtk/extconf.rb
new file mode 100644
index 0000000000..c0e788037e
--- /dev/null
+++ b/gc/mmtk/extconf.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require_relative "../extconf_base"
+
+# Statically link `libmmtk_ruby.a`
+$LIBS << " $(MMTK_BUILD)/$(LIBMMTK_RUBY)"
+
+rustsrcs = Dir.glob("src/*.rs", base: __dir__).map {|s| "$(srcdir)/#{s}"}
+
+create_gc_makefile("mmtk") do |makefile|
+ [
+ *makefile,
+
+ <<~MAKEFILE,
+ MMTK_BUILD = debug
+ LIBMMTK_RUBY = libmmtk_ruby.#$LIBEXT
+ RUSTSRCS = #{rustsrcs.join(" \\\n\t ")}
+
+ ifeq ($(MMTK_BUILD), debug)
+ CPPFLAGS += -DMMTK_DEBUG
+ endif
+ MAKEFILE
+ ]
+end
diff --git a/gc/mmtk/mmtk.c b/gc/mmtk/mmtk.c
new file mode 100644
index 0000000000..96e9e32ef6
--- /dev/null
+++ b/gc/mmtk/mmtk.c
@@ -0,0 +1,1655 @@
+#include <pthread.h>
+#include <stdbool.h>
+
+#include "ruby/assert.h"
+#include "ruby/atomic.h"
+#include "ruby/debug.h"
+
+#include "gc/gc.h"
+#include "gc/gc_impl.h"
+#include "gc/mmtk/mmtk.h"
+
+#include "ccan/list/list.h"
+#include "darray.h"
+
+#ifdef __APPLE__
+#include <sys/sysctl.h>
+#endif
+
+struct objspace {
+ bool measure_gc_time;
+ bool gc_stress;
+
+ size_t gc_count;
+ size_t moving_gc_count;
+ size_t total_gc_time;
+ size_t total_allocated_objects;
+
+ st_table *finalizer_table;
+ struct MMTk_final_job *finalizer_jobs;
+ rb_postponed_job_handle_t finalizer_postponed_job;
+
+ struct ccan_list_head ractor_caches;
+ unsigned long live_ractor_cache_count;
+
+ pthread_mutex_t mutex;
+ rb_atomic_t mutator_blocking_count;
+ bool world_stopped;
+ pthread_cond_t cond_world_stopped;
+ pthread_cond_t cond_world_started;
+ size_t start_the_world_count;
+
+ pthread_mutex_t event_hook_mutex;
+
+ struct {
+ bool gc_thread_crashed;
+ char crash_msg[256];
+ } crash_context;
+
+ struct rb_gc_vm_context vm_context;
+
+ unsigned int fork_hook_vm_lock_lev;
+};
+
+#define OBJ_FREE_BUF_CAPACITY 128
+
+struct MMTk_ractor_cache {
+ struct ccan_list_node list_node;
+
+ MMTk_Mutator *mutator;
+ bool gc_mutator_p;
+
+ MMTk_BumpPointer *bump_pointer;
+
+ MMTk_ObjectReference obj_free_parallel_buf[OBJ_FREE_BUF_CAPACITY];
+ size_t obj_free_parallel_count;
+ MMTk_ObjectReference obj_free_non_parallel_buf[OBJ_FREE_BUF_CAPACITY];
+ size_t obj_free_non_parallel_count;
+};
+
+struct MMTk_final_job {
+ struct MMTk_final_job *next;
+ enum {
+ MMTK_FINAL_JOB_DFREE,
+ MMTK_FINAL_JOB_FINALIZE,
+ } kind;
+ union {
+ struct {
+ void (*func)(void *);
+ void *data;
+ } dfree;
+ struct {
+ /* HACK: we store the object ID on the 0th element of this array. */
+ VALUE finalizer_array;
+ } finalize;
+ } as;
+};
+
+#ifdef RB_THREAD_LOCAL_SPECIFIER
+RB_THREAD_LOCAL_SPECIFIER struct MMTk_GCThreadTLS *rb_mmtk_gc_thread_tls;
+
+RB_THREAD_LOCAL_SPECIFIER VALUE marking_parent_object;
+#else
+# error We currently need language-supported TLS
+#endif
+
+#ifdef MMTK_DEBUG
+# define MMTK_ASSERT(expr, ...) RUBY_ASSERT_ALWAYS(expr, #expr RBIMPL_VA_OPT_ARGS(__VA_ARGS__))
+#else
+# define MMTK_ASSERT(expr, ...) ((void)0)
+#endif
+
+#include <pthread.h>
+
+static inline VALUE rb_mmtk_call_object_closure(VALUE obj, bool pin);
+
+static void
+rb_mmtk_init_gc_worker_thread(MMTk_VMWorkerThread gc_thread_tls)
+{
+ rb_mmtk_gc_thread_tls = gc_thread_tls;
+}
+
+static bool
+rb_mmtk_is_mutator(void)
+{
+ return ruby_native_thread_p();
+}
+
+static void
+rb_mmtk_stop_the_world(void)
+{
+ struct objspace *objspace = rb_gc_get_objspace();
+
+ int err;
+ if ((err = pthread_mutex_lock(&objspace->mutex)) != 0) {
+ rb_bug("ERROR: cannot lock objspace->mutex: %s", strerror(err));
+ }
+
+ while (!objspace->world_stopped) {
+ pthread_cond_wait(&objspace->cond_world_stopped, &objspace->mutex);
+ }
+
+ if ((err = pthread_mutex_unlock(&objspace->mutex)) != 0) {
+ rb_bug("ERROR: cannot release objspace->mutex: %s", strerror(err));
+ }
+}
+
+static void
+rb_mmtk_resume_mutators(bool current_gc_may_move)
+{
+ struct objspace *objspace = rb_gc_get_objspace();
+
+ int err;
+ if ((err = pthread_mutex_lock(&objspace->mutex)) != 0) {
+ rb_bug("ERROR: cannot lock objspace->mutex: %s", strerror(err));
+ }
+
+ objspace->world_stopped = false;
+ objspace->gc_count++;
+ if (current_gc_may_move) objspace->moving_gc_count++;
+ pthread_cond_broadcast(&objspace->cond_world_started);
+
+ if ((err = pthread_mutex_unlock(&objspace->mutex)) != 0) {
+ rb_bug("ERROR: cannot release objspace->mutex: %s", strerror(err));
+ }
+}
+
+static void mmtk_flush_obj_free_buffer(struct MMTk_ractor_cache *cache);
+
+static void
+rb_mmtk_block_for_gc(MMTk_VMMutatorThread mutator)
+{
+ struct objspace *objspace = rb_gc_get_objspace();
+
+ size_t starting_gc_count = objspace->gc_count;
+ RUBY_ATOMIC_INC(objspace->mutator_blocking_count);
+ int lock_lev = RB_GC_VM_LOCK();
+ RUBY_ATOMIC_DEC(objspace->mutator_blocking_count);
+ int err;
+ if ((err = pthread_mutex_lock(&objspace->mutex)) != 0) {
+ rb_bug("ERROR: cannot lock objspace->mutex: %s", strerror(err));
+ }
+
+ if (objspace->gc_count == starting_gc_count) {
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_START);
+
+ rb_gc_initialize_vm_context(&objspace->vm_context);
+
+ mutator->gc_mutator_p = true;
+
+ struct timespec gc_start_time;
+ if (objspace->measure_gc_time) {
+ clock_gettime(CLOCK_MONOTONIC, &gc_start_time);
+ }
+
+ rb_gc_save_machine_context();
+
+ rb_gc_vm_barrier();
+
+ struct MMTk_ractor_cache *rc;
+ ccan_list_for_each(&objspace->ractor_caches, rc, list_node) {
+ mmtk_flush_obj_free_buffer(rc);
+ }
+
+ objspace->world_stopped = true;
+
+ pthread_cond_broadcast(&objspace->cond_world_stopped);
+
+ // Wait for GC end
+ while (objspace->world_stopped) {
+ pthread_cond_wait(&objspace->cond_world_started, &objspace->mutex);
+ }
+
+ if (RB_UNLIKELY(objspace->crash_context.gc_thread_crashed)) {
+ rb_bug("%s", objspace->crash_context.crash_msg);
+ }
+
+ if (objspace->measure_gc_time) {
+ struct timespec gc_end_time;
+ clock_gettime(CLOCK_MONOTONIC, &gc_end_time);
+
+ objspace->total_gc_time +=
+ (gc_end_time.tv_sec - gc_start_time.tv_sec) * (1000 * 1000 * 1000) +
+ (gc_end_time.tv_nsec - gc_start_time.tv_nsec);
+ }
+ }
+
+ if ((err = pthread_mutex_unlock(&objspace->mutex)) != 0) {
+ rb_bug("ERROR: cannot release objspace->mutex: %s", strerror(err));
+ }
+ RB_GC_VM_UNLOCK(lock_lev);
+}
+
+static void
+rb_mmtk_before_updating_jit_code(void)
+{
+ rb_gc_before_updating_jit_code();
+}
+
+static void
+rb_mmtk_after_updating_jit_code(void)
+{
+ rb_gc_after_updating_jit_code();
+}
+
+static size_t
+rb_mmtk_number_of_mutators(void)
+{
+ struct objspace *objspace = rb_gc_get_objspace();
+ return objspace->live_ractor_cache_count;
+}
+
+static void
+rb_mmtk_get_mutators(void (*visit_mutator)(MMTk_Mutator *mutator, void *data), void *data)
+{
+ struct objspace *objspace = rb_gc_get_objspace();
+ struct MMTk_ractor_cache *ractor_cache;
+
+ ccan_list_for_each(&objspace->ractor_caches, ractor_cache, list_node) {
+ visit_mutator(ractor_cache->mutator, data);
+ }
+}
+
+static void
+rb_mmtk_scan_gc_roots(void)
+{
+ struct objspace *objspace = rb_gc_get_objspace();
+
+ rb_gc_mark_roots(objspace, NULL);
+}
+
+static int
+pin_value(st_data_t key, st_data_t value, st_data_t data)
+{
+ rb_gc_impl_mark_and_pin((void *)data, (VALUE)value);
+
+ return ST_CONTINUE;
+}
+
+static void
+rb_mmtk_scan_objspace(void)
+{
+ struct objspace *objspace = rb_gc_get_objspace();
+
+ if (objspace->finalizer_table != NULL) {
+ st_foreach(objspace->finalizer_table, pin_value, (st_data_t)objspace);
+ }
+
+ struct MMTk_final_job *job = objspace->finalizer_jobs;
+ while (job != NULL) {
+ switch (job->kind) {
+ case MMTK_FINAL_JOB_DFREE:
+ break;
+ case MMTK_FINAL_JOB_FINALIZE:
+ rb_gc_impl_mark(objspace, job->as.finalize.finalizer_array);
+ break;
+ default:
+ rb_bug("rb_mmtk_scan_objspace: unknown final job type %d", job->kind);
+ }
+
+ job = job->next;
+ }
+}
+
+static void
+rb_mmtk_move_obj_during_marking(MMTk_ObjectReference from, MMTk_ObjectReference to)
+{
+ rb_gc_move_obj_during_marking((VALUE)from, (VALUE)to);
+}
+
+static void
+rb_mmtk_update_object_references(MMTk_ObjectReference mmtk_object)
+{
+ VALUE object = (VALUE)mmtk_object;
+
+ if (!RB_FL_TEST(object, RUBY_FL_WEAK_REFERENCE)) {
+ marking_parent_object = object;
+ rb_gc_update_object_references(rb_gc_get_objspace(), object);
+ marking_parent_object = 0;
+ }
+}
+
+static void
+rb_mmtk_call_gc_mark_children(MMTk_ObjectReference object)
+{
+ marking_parent_object = (VALUE)object;
+ rb_gc_mark_children(rb_gc_get_objspace(), (VALUE)object);
+ marking_parent_object = 0;
+}
+
+static void
+rb_mmtk_handle_weak_references(MMTk_ObjectReference mmtk_object, bool moving)
+{
+ VALUE object = (VALUE)mmtk_object;
+
+ marking_parent_object = object;
+
+ rb_gc_handle_weak_references(object);
+
+ if (moving) {
+ rb_gc_update_object_references(rb_gc_get_objspace(), object);
+ }
+
+ marking_parent_object = 0;
+}
+
+static void
+rb_mmtk_call_obj_free(MMTk_ObjectReference object)
+{
+ VALUE obj = (VALUE)object;
+ struct objspace *objspace = rb_gc_get_objspace();
+
+ if (RB_UNLIKELY(rb_gc_event_hook_required_p(RUBY_INTERNAL_EVENT_FREEOBJ))) {
+ pthread_mutex_lock(&objspace->event_hook_mutex);
+ rb_gc_event_hook(obj, RUBY_INTERNAL_EVENT_FREEOBJ);
+ pthread_mutex_unlock(&objspace->event_hook_mutex);
+ }
+
+ rb_gc_obj_free(objspace, obj);
+
+#ifdef MMTK_DEBUG
+ memset((void *)obj, 0, rb_gc_impl_obj_slot_size(obj));
+#endif
+}
+
+static size_t
+rb_mmtk_vm_live_bytes(void)
+{
+ return 0;
+}
+
+static void
+make_final_job(struct objspace *objspace, VALUE obj, VALUE table)
+{
+ MMTK_ASSERT(RB_BUILTIN_TYPE(table) == T_ARRAY);
+
+ struct MMTk_final_job *job = xmalloc(sizeof(struct MMTk_final_job));
+ job->next = objspace->finalizer_jobs;
+ job->kind = MMTK_FINAL_JOB_FINALIZE;
+ job->as.finalize.finalizer_array = table;
+
+ objspace->finalizer_jobs = job;
+}
+
+static int
+rb_mmtk_update_finalizer_table_i(st_data_t key, st_data_t value, st_data_t data, int error)
+{
+ MMTK_ASSERT(mmtk_is_reachable((MMTk_ObjectReference)value));
+ MMTK_ASSERT(RB_BUILTIN_TYPE(value) == T_ARRAY);
+
+ struct objspace *objspace = (struct objspace *)data;
+
+ if (mmtk_is_reachable((MMTk_ObjectReference)key)) {
+ VALUE new_key_location = rb_mmtk_call_object_closure((VALUE)key, false);
+
+ MMTK_ASSERT(RB_FL_TEST(new_key_location, RUBY_FL_FINALIZE));
+
+ if (new_key_location != key) {
+ return ST_REPLACE;
+ }
+ }
+ else {
+ make_final_job(objspace, (VALUE)key, (VALUE)value);
+
+ rb_postponed_job_trigger(objspace->finalizer_postponed_job);
+
+ return ST_DELETE;
+ }
+
+ return ST_CONTINUE;
+}
+
+static int
+rb_mmtk_update_finalizer_table_replace_i(st_data_t *key, st_data_t *value, st_data_t data, int existing)
+{
+ *key = rb_mmtk_call_object_closure((VALUE)*key, false);
+
+ return ST_CONTINUE;
+}
+
+static void
+rb_mmtk_update_finalizer_table(void)
+{
+ struct objspace *objspace = rb_gc_get_objspace();
+
+ st_foreach_with_replace(
+ objspace->finalizer_table,
+ rb_mmtk_update_finalizer_table_i,
+ rb_mmtk_update_finalizer_table_replace_i,
+ (st_data_t)objspace
+ );
+}
+
+static int
+rb_mmtk_global_tables_count(void)
+{
+ return RB_GC_VM_WEAK_TABLE_COUNT;
+}
+
+static inline VALUE rb_mmtk_call_object_closure(VALUE obj, bool pin);
+
+static int
+rb_mmtk_update_global_tables_i(VALUE val, void *data)
+{
+ if (!mmtk_is_reachable((MMTk_ObjectReference)val)) {
+ return ST_DELETE;
+ }
+
+ // TODO: check only if in moving GC
+ if (rb_mmtk_call_object_closure(val, false) != val) {
+ return ST_REPLACE;
+ }
+
+ return ST_CONTINUE;
+}
+
+static int
+rb_mmtk_update_global_tables_replace_i(VALUE *ptr, void *data)
+{
+ // TODO: cache the new location so we don't call rb_mmtk_call_object_closure twice
+ *ptr = rb_mmtk_call_object_closure(*ptr, false);
+
+ return ST_CONTINUE;
+}
+
+static void
+rb_mmtk_update_global_tables(int table, bool moving)
+{
+ MMTK_ASSERT(table < RB_GC_VM_WEAK_TABLE_COUNT);
+
+ rb_gc_vm_weak_table_foreach(
+ rb_mmtk_update_global_tables_i,
+ rb_mmtk_update_global_tables_replace_i,
+ NULL,
+ !moving,
+ (enum rb_gc_vm_weak_tables)table
+ );
+}
+
+static bool
+rb_mmtk_special_const_p(MMTk_ObjectReference object)
+{
+ VALUE obj = (VALUE)object;
+
+ return RB_SPECIAL_CONST_P(obj);
+}
+
+RBIMPL_ATTR_FORMAT(RBIMPL_PRINTF_FORMAT, 1, 2)
+RBIMPL_ATTR_NORETURN()
+static void
+rb_mmtk_gc_thread_bug(const char *msg, ...)
+{
+ struct objspace *objspace = rb_gc_get_objspace();
+
+ objspace->crash_context.gc_thread_crashed = true;
+
+ va_list args;
+ va_start(args, msg);
+ vsnprintf(objspace->crash_context.crash_msg, sizeof(objspace->crash_context.crash_msg), msg, args);
+ va_end(args);
+
+ fprintf(stderr, "-- GC thread backtrace "
+ "-------------------------------------------\n");
+ rb_gc_print_backtrace();
+ fprintf(stderr, "\n");
+
+ rb_mmtk_resume_mutators(false);
+
+ sleep(5);
+
+ rb_bug("rb_mmtk_gc_thread_bug");
+}
+
+static void
+rb_mmtk_gc_thread_panic_handler(void)
+{
+ rb_mmtk_gc_thread_bug("MMTk GC thread panicked");
+}
+
+RBIMPL_ATTR_NORETURN()
+static void
+rb_mmtk_mutator_thread_panic_handler(void)
+{
+ rb_bug("Ruby mutator thread panicked");
+}
+
+// Bootup
+MMTk_RubyUpcalls ruby_upcalls = {
+ rb_mmtk_init_gc_worker_thread,
+ rb_mmtk_is_mutator,
+ rb_mmtk_stop_the_world,
+ rb_mmtk_resume_mutators,
+ rb_mmtk_block_for_gc,
+ rb_mmtk_before_updating_jit_code,
+ rb_mmtk_after_updating_jit_code,
+ rb_mmtk_number_of_mutators,
+ rb_mmtk_get_mutators,
+ rb_mmtk_scan_gc_roots,
+ rb_mmtk_scan_objspace,
+ rb_mmtk_move_obj_during_marking,
+ rb_mmtk_update_object_references,
+ rb_mmtk_call_gc_mark_children,
+ rb_mmtk_handle_weak_references,
+ rb_mmtk_call_obj_free,
+ rb_mmtk_vm_live_bytes,
+ rb_mmtk_update_global_tables,
+ rb_mmtk_global_tables_count,
+ rb_mmtk_update_finalizer_table,
+ rb_mmtk_special_const_p,
+ rb_mmtk_mutator_thread_panic_handler,
+ rb_mmtk_gc_thread_panic_handler,
+};
+
+// Use max 80% of the available memory by default for MMTk
+#define RB_MMTK_HEAP_LIMIT_PERC 80
+#define RB_MMTK_DEFAULT_HEAP_MIN (1024 * 1024)
+#define RB_MMTK_DEFAULT_HEAP_MAX (rb_mmtk_system_physical_memory() / 100 * RB_MMTK_HEAP_LIMIT_PERC)
+
+enum mmtk_heap_mode {
+ RB_MMTK_DYNAMIC_HEAP,
+ RB_MMTK_FIXED_HEAP
+};
+
+MMTk_Builder *
+rb_mmtk_builder_init(void)
+{
+ MMTk_Builder *builder = mmtk_builder_default();
+ return builder;
+}
+
+void *
+rb_gc_impl_objspace_alloc(void)
+{
+ MMTk_Builder *builder = rb_mmtk_builder_init();
+ MMTk_RubyBindingOptions binding_options = {
+ .suffix_size = RB_GC_OBJ_SUFFIX_SIZE,
+ };
+ mmtk_init_binding(builder, &binding_options, &ruby_upcalls);
+
+ return calloc(1, sizeof(struct objspace));
+}
+
+static void gc_run_finalizers(void *data);
+
+void
+rb_gc_impl_objspace_init(void *objspace_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ objspace->measure_gc_time = true;
+
+ objspace->finalizer_table = st_init_numtable();
+ objspace->finalizer_postponed_job = rb_postponed_job_preregister(0, gc_run_finalizers, objspace);
+
+ ccan_list_head_init(&objspace->ractor_caches);
+
+ objspace->mutex = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;
+ objspace->cond_world_stopped = (pthread_cond_t)PTHREAD_COND_INITIALIZER;
+ objspace->cond_world_started = (pthread_cond_t)PTHREAD_COND_INITIALIZER;
+
+ objspace->event_hook_mutex = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;
+}
+
+void
+rb_gc_impl_objspace_free(void *objspace_ptr)
+{
+ free(objspace_ptr);
+}
+
+void *
+rb_gc_impl_ractor_cache_alloc(void *objspace_ptr, void *ractor)
+{
+ struct objspace *objspace = objspace_ptr;
+ if (objspace->live_ractor_cache_count == 0) {
+ mmtk_initialize_collection(ractor);
+ }
+ objspace->live_ractor_cache_count++;
+
+ struct MMTk_ractor_cache *cache = calloc(1, sizeof(struct MMTk_ractor_cache));
+ ccan_list_add(&objspace->ractor_caches, &cache->list_node);
+
+ cache->mutator = mmtk_bind_mutator(cache);
+ cache->bump_pointer = mmtk_get_bump_pointer_allocator(cache->mutator);
+
+ return cache;
+}
+
+void
+rb_gc_impl_ractor_cache_free(void *objspace_ptr, void *cache_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+ struct MMTk_ractor_cache *cache = cache_ptr;
+
+ ccan_list_del(&cache->list_node);
+
+ mmtk_flush_obj_free_buffer(cache);
+
+ if (ruby_free_at_exit_p()) {
+ MMTK_ASSERT(objspace->live_ractor_cache_count > 0);
+ }
+ else {
+ MMTK_ASSERT(objspace->live_ractor_cache_count > 1);
+ }
+
+ objspace->live_ractor_cache_count--;
+
+ mmtk_destroy_mutator(cache->mutator);
+}
+
+void rb_gc_impl_set_params(void *objspace_ptr) { }
+
+static VALUE gc_verify_internal_consistency(VALUE self) { return Qnil; }
+
+#if SIZEOF_VALUE >= 8
+#define MMTK_HEAP_COUNT 12
+#define MMTK_MAX_OBJ_SIZE 1024
+static size_t heap_sizes[MMTK_HEAP_COUNT + 1] = {
+ 32, 40, 64, 80, 96, 128, 160, 256, 512, 640, 768, MMTK_MAX_OBJ_SIZE, 0
+};
+#else
+#define MMTK_HEAP_COUNT 5
+#define MMTK_MAX_OBJ_SIZE 512
+static size_t heap_sizes[MMTK_HEAP_COUNT + 1] = {
+ 32, 64, 128, 256, MMTK_MAX_OBJ_SIZE, 0
+};
+#endif
+
+void
+rb_gc_impl_init(void)
+{
+ VALUE gc_constants = rb_hash_new();
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVALUE_SIZE")), SIZET2NUM(SIZEOF_VALUE >= 8 ? 64 : 32));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RBASIC_SIZE")), SIZET2NUM(sizeof(struct RBasic)));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVALUE_OVERHEAD")), INT2NUM(0));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVARGC_MAX_ALLOCATE_SIZE")), LONG2FIX(MMTK_MAX_OBJ_SIZE));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("HEAP_COUNT")), LONG2FIX(MMTK_HEAP_COUNT));
+ // TODO: correctly set RVALUE_OLD_AGE when we have generational GC support
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVALUE_OLD_AGE")), INT2FIX(0));
+ OBJ_FREEZE(gc_constants);
+ rb_define_const(rb_mGC, "INTERNAL_CONSTANTS", gc_constants);
+
+ // no-ops for compatibility
+ rb_define_singleton_method(rb_mGC, "verify_internal_consistency", gc_verify_internal_consistency, 0);
+
+ rb_define_singleton_method(rb_mGC, "compact", rb_f_notimplement, 0);
+ rb_define_singleton_method(rb_mGC, "auto_compact", rb_f_notimplement, 0);
+ rb_define_singleton_method(rb_mGC, "auto_compact=", rb_f_notimplement, 1);
+ rb_define_singleton_method(rb_mGC, "latest_compact_info", rb_f_notimplement, 0);
+ rb_define_singleton_method(rb_mGC, "verify_compaction_references", rb_f_notimplement, -1);
+}
+
+size_t *
+rb_gc_impl_heap_sizes(void *objspace_ptr)
+{
+ return heap_sizes;
+}
+
+int
+rb_mmtk_obj_free_iter_wrapper(VALUE obj, void *data)
+{
+ struct objspace *objspace = data;
+
+ if (!RB_TYPE_P(obj, T_NONE)) {
+ rb_gc_obj_free_vm_weak_references(obj);
+ rb_gc_obj_free(objspace, obj);
+ }
+
+ return 0;
+}
+
+// Shutdown
+static void each_object(struct objspace *objspace, int (*func)(VALUE, void *), void *data);
+
+void
+rb_gc_impl_shutdown_free_objects(void *objspace_ptr)
+{
+ mmtk_set_gc_enabled(false);
+ each_object(objspace_ptr, rb_mmtk_obj_free_iter_wrapper, objspace_ptr);
+ mmtk_set_gc_enabled(true);
+}
+
+// GC
+void
+rb_gc_impl_start(void *objspace_ptr, bool full_mark, bool immediate_mark, bool immediate_sweep, bool compact)
+{
+ mmtk_handle_user_collection_request(rb_gc_get_ractor_newobj_cache(), true, full_mark);
+}
+
+bool
+rb_gc_impl_during_gc_p(void *objspace_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+ return objspace->world_stopped;
+}
+
+static void
+rb_gc_impl_prepare_heap_i(MMTk_ObjectReference obj, void *d)
+{
+ rb_gc_prepare_heap_process_object((VALUE)obj);
+}
+
+void
+rb_gc_impl_prepare_heap(void *objspace_ptr)
+{
+ mmtk_enumerate_objects(rb_gc_impl_prepare_heap_i, NULL);
+}
+
+void
+rb_gc_impl_gc_enable(void *objspace_ptr)
+{
+ mmtk_set_gc_enabled(true);
+}
+
+void
+rb_gc_impl_gc_disable(void *objspace_ptr, bool finish_current_gc)
+{
+ mmtk_set_gc_enabled(false);
+}
+
+bool
+rb_gc_impl_gc_enabled_p(void *objspace_ptr)
+{
+ return mmtk_gc_enabled_p();
+}
+
+void
+rb_gc_impl_stress_set(void *objspace_ptr, VALUE flag)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ objspace->gc_stress = RTEST(flag);
+}
+
+VALUE
+rb_gc_impl_stress_get(void *objspace_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ return objspace->gc_stress ? Qtrue : Qfalse;
+}
+
+VALUE
+rb_gc_impl_config_get(void *objspace_ptr)
+{
+ VALUE hash = rb_hash_new();
+
+ rb_hash_aset(hash, ID2SYM(rb_intern_const("mmtk_worker_count")), RB_ULONG2NUM(mmtk_worker_count()));
+ rb_hash_aset(hash, ID2SYM(rb_intern_const("mmtk_plan")), rb_str_new_cstr((const char *)mmtk_plan()));
+ rb_hash_aset(hash, ID2SYM(rb_intern_const("mmtk_heap_mode")), rb_str_new_cstr((const char *)mmtk_heap_mode()));
+ size_t heap_min = mmtk_heap_min();
+ if (heap_min > 0) rb_hash_aset(hash, ID2SYM(rb_intern_const("mmtk_heap_min")), RB_ULONG2NUM(heap_min));
+ rb_hash_aset(hash, ID2SYM(rb_intern_const("mmtk_heap_max")), RB_ULONG2NUM(mmtk_heap_max()));
+
+ return hash;
+}
+
+void
+rb_gc_impl_config_set(void *objspace_ptr, VALUE hash)
+{
+ // TODO
+}
+
+struct rb_gc_vm_context *
+rb_gc_impl_get_vm_context(void *objspace_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ return &objspace->vm_context;
+}
+
+// Object allocation
+
+static VALUE
+rb_mmtk_alloc_fast_path(struct objspace *objspace, struct MMTk_ractor_cache *ractor_cache, size_t size, size_t align)
+{
+ MMTk_BumpPointer *bump_pointer = ractor_cache->bump_pointer;
+ if (bump_pointer == NULL) return 0;
+
+ uintptr_t cursor = bump_pointer->cursor;
+
+ // Ensure cursor is aligned
+ size_t mask = align - 1;
+ cursor = (cursor + mask) & ~mask;
+
+ cursor += size;
+
+ if (cursor > bump_pointer->limit) {
+ return 0;
+ }
+ else {
+ VALUE obj = cursor - size;
+ bump_pointer->cursor = cursor;
+ return obj;
+ }
+}
+
+static bool
+obj_can_parallel_free_p(VALUE obj)
+{
+ switch (RB_BUILTIN_TYPE(obj)) {
+ case T_ARRAY:
+ case T_BIGNUM:
+ case T_COMPLEX:
+ case T_FLOAT:
+ case T_HASH:
+ case T_OBJECT:
+ case T_RATIONAL:
+ case T_REGEXP:
+ case T_STRING:
+ case T_STRUCT:
+ case T_SYMBOL:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static void
+mmtk_flush_obj_free_buffer(struct MMTk_ractor_cache *cache)
+{
+ if (cache->obj_free_parallel_count > 0) {
+ mmtk_add_obj_free_candidates(cache->obj_free_parallel_buf,
+ cache->obj_free_parallel_count, true);
+ cache->obj_free_parallel_count = 0;
+ }
+ if (cache->obj_free_non_parallel_count > 0) {
+ mmtk_add_obj_free_candidates(cache->obj_free_non_parallel_buf,
+ cache->obj_free_non_parallel_count, false);
+ cache->obj_free_non_parallel_count = 0;
+ }
+}
+
+static inline void
+mmtk_buffer_obj_free_candidate(struct MMTk_ractor_cache *cache, VALUE obj)
+{
+ if (obj_can_parallel_free_p(obj)) {
+ cache->obj_free_parallel_buf[cache->obj_free_parallel_count++] = (MMTk_ObjectReference)obj;
+ if (cache->obj_free_parallel_count >= OBJ_FREE_BUF_CAPACITY) {
+ mmtk_add_obj_free_candidates(cache->obj_free_parallel_buf,
+ cache->obj_free_parallel_count, true);
+ cache->obj_free_parallel_count = 0;
+ }
+ }
+ else {
+ cache->obj_free_non_parallel_buf[cache->obj_free_non_parallel_count++] = (MMTk_ObjectReference)obj;
+ if (cache->obj_free_non_parallel_count >= OBJ_FREE_BUF_CAPACITY) {
+ mmtk_add_obj_free_candidates(cache->obj_free_non_parallel_buf,
+ cache->obj_free_non_parallel_count, false);
+ cache->obj_free_non_parallel_count = 0;
+ }
+ }
+}
+
+VALUE
+rb_gc_impl_new_obj(void *objspace_ptr, void *cache_ptr, VALUE klass, VALUE flags, bool wb_protected, size_t alloc_size)
+{
+#define MMTK_ALLOCATION_SEMANTICS_DEFAULT 0
+ struct objspace *objspace = objspace_ptr;
+ struct MMTk_ractor_cache *ractor_cache = cache_ptr;
+
+ if (alloc_size > MMTK_MAX_OBJ_SIZE) rb_bug("too big");
+ for (int i = 0; i < MMTK_HEAP_COUNT; i++) {
+ if (alloc_size == heap_sizes[i]) break;
+ if (alloc_size < heap_sizes[i]) {
+ alloc_size = heap_sizes[i];
+ break;
+ }
+ }
+
+ if (objspace->gc_stress) {
+ mmtk_handle_user_collection_request(ractor_cache, false, false);
+ }
+
+ // Layout: [hidden size header (sizeof(VALUE))][payload (alloc_size)][suffix (RB_GC_OBJ_SUFFIX_SIZE)]
+ alloc_size += sizeof(VALUE) + RB_GC_OBJ_SUFFIX_SIZE;
+
+ VALUE *alloc_obj = (VALUE *)rb_mmtk_alloc_fast_path(objspace, ractor_cache, alloc_size, MMTk_MIN_OBJ_ALIGN);
+ if (!alloc_obj) {
+ alloc_obj = mmtk_alloc(ractor_cache->mutator, alloc_size, MMTk_MIN_OBJ_ALIGN, 0, MMTK_ALLOCATION_SEMANTICS_DEFAULT);
+ }
+
+ alloc_obj++;
+ alloc_obj[-1] = alloc_size - sizeof(VALUE) - RB_GC_OBJ_SUFFIX_SIZE;
+ alloc_obj[0] = flags;
+ alloc_obj[1] = klass;
+
+ // TODO: implement fast path for mmtk_post_alloc
+ mmtk_post_alloc(ractor_cache->mutator, (void*)alloc_obj, alloc_size, MMTK_ALLOCATION_SEMANTICS_DEFAULT);
+
+ // TODO: only add when object needs obj_free to be called
+ mmtk_buffer_obj_free_candidate(ractor_cache, (VALUE)alloc_obj);
+
+ objspace->total_allocated_objects++;
+
+ return (VALUE)alloc_obj;
+}
+
+size_t
+rb_gc_impl_obj_slot_size(VALUE obj)
+{
+ return ((VALUE *)obj)[-1];
+}
+
+size_t
+rb_gc_impl_heap_id_for_size(void *objspace_ptr, size_t size)
+{
+ for (int i = 0; i < MMTK_HEAP_COUNT; i++) {
+ if (size == heap_sizes[i]) return i;
+ if (size < heap_sizes[i]) return i;
+ }
+
+ rb_bug("size too big");
+}
+
+bool
+rb_gc_impl_size_allocatable_p(size_t size)
+{
+ return size <= MMTK_MAX_OBJ_SIZE;
+}
+
+// Malloc
+void *
+rb_gc_impl_malloc(void *objspace_ptr, size_t size, bool gc_allowed)
+{
+ // TODO: don't use system malloc
+ return malloc(size);
+}
+
+void *
+rb_gc_impl_calloc(void *objspace_ptr, size_t size, bool gc_allowed)
+{
+ // TODO: don't use system calloc
+ return calloc(1, size);
+}
+
+void *
+rb_gc_impl_realloc(void *objspace_ptr, void *ptr, size_t new_size, size_t old_size, bool gc_allowed)
+{
+ // TODO: don't use system realloc
+ return realloc(ptr, new_size);
+}
+
+void
+rb_gc_impl_free(void *objspace_ptr, void *ptr, size_t old_size)
+{
+ // TODO: don't use system free
+ free(ptr);
+}
+
+void rb_gc_impl_adjust_memory_usage(void *objspace_ptr, ssize_t diff) { }
+
+// Marking
+static inline VALUE
+rb_mmtk_call_object_closure(VALUE obj, bool pin)
+{
+ if (RB_UNLIKELY(RB_BUILTIN_TYPE(obj) == T_NONE)) {
+ const size_t info_size = 256;
+ char obj_info_buf[info_size];
+ rb_raw_obj_info(obj_info_buf, info_size, obj);
+
+ char parent_obj_info_buf[info_size];
+ rb_raw_obj_info(parent_obj_info_buf, info_size, marking_parent_object);
+
+ rb_mmtk_gc_thread_bug("try to mark T_NONE object (obj: %s, parent: %s)", obj_info_buf, parent_obj_info_buf);
+ }
+
+ return (VALUE)rb_mmtk_gc_thread_tls->object_closure.c_function(
+ rb_mmtk_gc_thread_tls->object_closure.rust_closure,
+ rb_mmtk_gc_thread_tls->gc_context,
+ (MMTk_ObjectReference)obj,
+ pin
+ );
+}
+
+void
+rb_gc_impl_mark(void *objspace_ptr, VALUE obj)
+{
+ if (RB_SPECIAL_CONST_P(obj)) return;
+
+ rb_mmtk_call_object_closure(obj, false);
+}
+
+void
+rb_gc_impl_mark_and_move(void *objspace_ptr, VALUE *ptr)
+{
+ if (RB_SPECIAL_CONST_P(*ptr)) return;
+
+ VALUE new_obj = rb_mmtk_call_object_closure(*ptr, false);
+ if (new_obj != *ptr) {
+ *ptr = new_obj;
+ }
+}
+
+void
+rb_gc_impl_mark_and_pin(void *objspace_ptr, VALUE obj)
+{
+ if (RB_SPECIAL_CONST_P(obj)) return;
+
+ rb_mmtk_call_object_closure(obj, true);
+}
+
+void
+rb_gc_impl_mark_maybe(void *objspace_ptr, VALUE obj)
+{
+ if (rb_gc_impl_pointer_to_heap_p(objspace_ptr, (const void *)obj)) {
+ rb_gc_impl_mark_and_pin(objspace_ptr, obj);
+ }
+}
+
+void
+rb_gc_impl_declare_weak_references(void *objspace_ptr, VALUE obj)
+{
+ RB_FL_SET(obj, RUBY_FL_WEAK_REFERENCE);
+ mmtk_declare_weak_references((MMTk_ObjectReference)obj);
+}
+
+bool
+rb_gc_impl_handle_weak_references_alive_p(void *objspace_ptr, VALUE obj)
+{
+ return mmtk_weak_references_alive_p((MMTk_ObjectReference)obj);
+}
+
+// Compaction
+void
+rb_gc_impl_register_pinning_obj(void *objspace_ptr, VALUE obj)
+{
+ mmtk_register_pinning_obj((MMTk_ObjectReference)obj);
+}
+
+bool
+rb_gc_impl_object_moved_p(void *objspace_ptr, VALUE obj)
+{
+ return rb_mmtk_call_object_closure(obj, false) != obj;
+}
+
+VALUE
+rb_gc_impl_location(void *objspace_ptr, VALUE obj)
+{
+ return rb_mmtk_call_object_closure(obj, false);
+}
+
+// Write barriers
+void
+rb_gc_impl_writebarrier(void *objspace_ptr, VALUE a, VALUE b)
+{
+ struct MMTk_ractor_cache *cache = rb_gc_get_ractor_newobj_cache();
+
+ if (SPECIAL_CONST_P(b)) return;
+
+#ifdef MMTK_DEBUG
+ if (!rb_gc_impl_pointer_to_heap_p(objspace_ptr, (void *)a)) {
+ char buff[256];
+ rb_bug("a: %s is not an object", rb_raw_obj_info(buff, 256, a));
+ }
+
+ if (!rb_gc_impl_pointer_to_heap_p(objspace_ptr, (void *)b)) {
+ char buff[256];
+ rb_bug("b: %s is not an object", rb_raw_obj_info(buff, 256, b));
+ }
+#endif
+
+ MMTK_ASSERT(BUILTIN_TYPE(a) != T_NONE);
+ MMTK_ASSERT(BUILTIN_TYPE(b) != T_NONE);
+
+ mmtk_object_reference_write_post(cache->mutator, (MMTk_ObjectReference)a);
+}
+
+void
+rb_gc_impl_writebarrier_unprotect(void *objspace_ptr, VALUE obj)
+{
+ mmtk_register_wb_unprotected_object((MMTk_ObjectReference)obj);
+}
+
+void
+rb_gc_impl_writebarrier_remember(void *objspace_ptr, VALUE obj)
+{
+ struct MMTk_ractor_cache *cache = rb_gc_get_ractor_newobj_cache();
+
+ mmtk_object_reference_write_post(cache->mutator, (MMTk_ObjectReference)obj);
+}
+
+// Heap walking
+static void
+each_objects_i(MMTk_ObjectReference obj, void *d)
+{
+ rb_darray(VALUE) *objs = d;
+
+ rb_darray_append(objs, (VALUE)obj);
+}
+
+static void
+each_object(struct objspace *objspace, int (*func)(VALUE, void *), void *data)
+{
+ rb_darray(VALUE) objs;
+ rb_darray_make(&objs, 0);
+
+ mmtk_enumerate_objects(each_objects_i, &objs);
+
+ VALUE *obj_ptr;
+ rb_darray_foreach(objs, i, obj_ptr) {
+ if (!mmtk_is_mmtk_object((MMTk_ObjectReference)*obj_ptr)) continue;
+
+ if (func(*obj_ptr, data) != 0) {
+ break;
+ }
+ }
+
+ rb_darray_free(objs);
+}
+
+struct rb_gc_impl_each_objects_data {
+ int (*func)(void *, void *, size_t, void *);
+ void *data;
+};
+
+static int
+rb_gc_impl_each_objects_i(VALUE obj, void *d)
+{
+ struct rb_gc_impl_each_objects_data *data = d;
+
+ size_t slot_size = rb_gc_impl_obj_slot_size(obj);
+
+ return data->func((void *)obj, (void *)(obj + slot_size), slot_size, data->data);
+}
+
+void
+rb_gc_impl_each_objects(void *objspace_ptr, int (*func)(void *, void *, size_t, void *), void *data)
+{
+ struct rb_gc_impl_each_objects_data each_objects_data = {
+ .func = func,
+ .data = data
+ };
+
+ each_object(objspace_ptr, rb_gc_impl_each_objects_i, &each_objects_data);
+}
+
+struct rb_gc_impl_each_object_data {
+ void (*func)(VALUE, void *);
+ void *data;
+};
+
+static int
+rb_gc_impl_each_object_i(VALUE obj, void *d)
+{
+ struct rb_gc_impl_each_object_data *data = d;
+
+ data->func(obj, data->data);
+
+ return 0;
+}
+
+void
+rb_gc_impl_each_object(void *objspace_ptr, void (*func)(VALUE, void *), void *data)
+{
+ struct rb_gc_impl_each_object_data each_object_data = {
+ .func = func,
+ .data = data
+ };
+
+ each_object(objspace_ptr, rb_gc_impl_each_object_i, &each_object_data);
+}
+
+// Finalizers
+static VALUE
+gc_run_finalizers_get_final(long i, void *data)
+{
+ VALUE table = (VALUE)data;
+
+ return RARRAY_AREF(table, i + 1);
+}
+
+static void
+gc_run_finalizers(void *data)
+{
+ struct objspace *objspace = data;
+
+ rb_gc_set_pending_interrupt();
+
+ while (objspace->finalizer_jobs != NULL) {
+ struct MMTk_final_job *job = objspace->finalizer_jobs;
+ objspace->finalizer_jobs = job->next;
+
+ switch (job->kind) {
+ case MMTK_FINAL_JOB_DFREE:
+ job->as.dfree.func(job->as.dfree.data);
+ break;
+ case MMTK_FINAL_JOB_FINALIZE: {
+ VALUE finalizer_array = job->as.finalize.finalizer_array;
+
+ rb_gc_run_obj_finalizer(
+ RARRAY_AREF(finalizer_array, 0),
+ RARRAY_LEN(finalizer_array) - 1,
+ gc_run_finalizers_get_final,
+ (void *)finalizer_array
+ );
+
+ RB_GC_GUARD(finalizer_array);
+ break;
+ }
+ }
+
+ xfree(job);
+ }
+
+ rb_gc_unset_pending_interrupt();
+}
+
+void
+rb_gc_impl_make_zombie(void *objspace_ptr, VALUE obj, void (*dfree)(void *), void *data)
+{
+ if (dfree == NULL) return;
+
+ struct objspace *objspace = objspace_ptr;
+
+ struct MMTk_final_job *job = xmalloc(sizeof(struct MMTk_final_job));
+ job->kind = MMTK_FINAL_JOB_DFREE;
+ job->as.dfree.func = dfree;
+ job->as.dfree.data = data;
+
+ struct MMTk_final_job *prev;
+ do {
+ job->next = objspace->finalizer_jobs;
+ prev = RUBY_ATOMIC_PTR_CAS(objspace->finalizer_jobs, job->next, job);
+ } while (prev != job->next);
+
+ if (!ruby_free_at_exit_p()) {
+ rb_postponed_job_trigger(objspace->finalizer_postponed_job);
+ }
+}
+
+VALUE
+rb_gc_impl_define_finalizer(void *objspace_ptr, VALUE obj, VALUE block)
+{
+ struct objspace *objspace = objspace_ptr;
+ VALUE table;
+ st_data_t data;
+
+ RBASIC(obj)->flags |= FL_FINALIZE;
+
+ int lev = RB_GC_VM_LOCK();
+
+ if (st_lookup(objspace->finalizer_table, obj, &data)) {
+ table = (VALUE)data;
+
+ /* avoid duplicate block, table is usually small */
+ {
+ long len = RARRAY_LEN(table);
+ long i;
+
+ for (i = 0; i < len; i++) {
+ VALUE recv = RARRAY_AREF(table, i);
+ if (rb_equal(recv, block)) {
+ RB_GC_VM_UNLOCK(lev);
+ return recv;
+ }
+ }
+ }
+
+ rb_ary_push(table, block);
+ }
+ else {
+ table = rb_ary_new3(2, rb_obj_id(obj), block);
+ rb_obj_hide(table);
+ st_add_direct(objspace->finalizer_table, obj, table);
+ }
+
+ RB_GC_VM_UNLOCK(lev);
+
+ return block;
+}
+
+void
+rb_gc_impl_undefine_finalizer(void *objspace_ptr, VALUE obj)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ st_data_t data = obj;
+
+ int lev = RB_GC_VM_LOCK();
+ st_delete(objspace->finalizer_table, &data, 0);
+ RB_GC_VM_UNLOCK(lev);
+
+ FL_UNSET(obj, FL_FINALIZE);
+}
+
+void
+rb_gc_impl_copy_finalizer(void *objspace_ptr, VALUE dest, VALUE obj)
+{
+ struct objspace *objspace = objspace_ptr;
+ VALUE table;
+ st_data_t data;
+
+ if (!FL_TEST(obj, FL_FINALIZE)) return;
+
+ int lev = RB_GC_VM_LOCK();
+ if (RB_LIKELY(st_lookup(objspace->finalizer_table, obj, &data))) {
+ table = rb_ary_dup((VALUE)data);
+ RARRAY_ASET(table, 0, rb_obj_id(dest));
+ st_insert(objspace->finalizer_table, dest, table);
+ FL_SET(dest, FL_FINALIZE);
+ }
+ else {
+ rb_bug("rb_gc_copy_finalizer: FL_FINALIZE set but not found in finalizer_table: %s", rb_obj_info(obj));
+ }
+ RB_GC_VM_UNLOCK(lev);
+}
+
+static int
+move_finalizer_from_table_i(st_data_t key, st_data_t val, st_data_t arg)
+{
+ struct objspace *objspace = (struct objspace *)arg;
+
+ make_final_job(objspace, (VALUE)key, (VALUE)val);
+
+ return ST_DELETE;
+}
+
+void
+rb_gc_impl_shutdown_call_finalizer(void *objspace_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ while (objspace->finalizer_table->num_entries) {
+ st_foreach(objspace->finalizer_table, move_finalizer_from_table_i, (st_data_t)objspace);
+
+ gc_run_finalizers(objspace);
+ }
+
+ unsigned int lev = RB_GC_VM_LOCK();
+ {
+ struct MMTk_ractor_cache *rc;
+ ccan_list_for_each(&objspace->ractor_caches, rc, list_node) {
+ mmtk_flush_obj_free_buffer(rc);
+ }
+
+ struct MMTk_RawVecOfObjRef registered_candidates = mmtk_get_all_obj_free_candidates();
+ for (size_t i = 0; i < registered_candidates.len; i++) {
+ VALUE obj = (VALUE)registered_candidates.ptr[i];
+
+ if (rb_gc_shutdown_call_finalizer_p(obj)) {
+ rb_gc_obj_free(objspace_ptr, obj);
+ RBASIC(obj)->flags = 0;
+ }
+ }
+ mmtk_free_raw_vec_of_obj_ref(registered_candidates);
+ }
+ RB_GC_VM_UNLOCK(lev);
+
+ gc_run_finalizers(objspace);
+}
+
+// Forking
+
+void
+rb_gc_impl_before_fork(void *objspace_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ retry:
+ objspace->fork_hook_vm_lock_lev = RB_GC_VM_LOCK();
+ rb_gc_vm_barrier();
+
+ /* At this point, we know that all the Ractors are paused because of the
+ * rb_gc_vm_barrier above. Since rb_mmtk_block_for_gc is a barrier point,
+ * one or more Ractors could be paused there. However, mmtk_before_fork is
+ * not compatible with that because it assumes that the MMTk workers are idle,
+ * but the workers are not idle because they are busy working on a GC.
+ *
+ * This essentially implements a trylock. It will optimistically lock but will
+ * release the lock if it detects that any other Ractors are waiting in
+ * rb_mmtk_block_for_gc.
+ */
+ rb_atomic_t mutator_blocking_count = RUBY_ATOMIC_LOAD(objspace->mutator_blocking_count);
+ if (mutator_blocking_count != 0) {
+ RB_GC_VM_UNLOCK(objspace->fork_hook_vm_lock_lev);
+ goto retry;
+ }
+
+ mmtk_before_fork();
+}
+
+void
+rb_gc_impl_after_fork(void *objspace_ptr, rb_pid_t pid)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ mmtk_after_fork(rb_gc_get_ractor_newobj_cache());
+
+ RB_GC_VM_UNLOCK(objspace->fork_hook_vm_lock_lev);
+}
+
+// Statistics
+
+void
+rb_gc_impl_set_measure_total_time(void *objspace_ptr, VALUE flag)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ objspace->measure_gc_time = RTEST(flag);
+}
+
+bool
+rb_gc_impl_get_measure_total_time(void *objspace_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ return objspace->measure_gc_time;
+}
+
+unsigned long long
+rb_gc_impl_get_total_time(void *objspace_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ return objspace->total_gc_time;
+}
+
+size_t
+rb_gc_impl_gc_count(void *objspace_ptr)
+{
+ struct objspace *objspace = objspace_ptr;
+
+ return objspace->gc_count;
+}
+
+VALUE
+rb_gc_impl_latest_gc_info(void *objspace_ptr, VALUE hash_or_key)
+{
+ VALUE hash = Qnil, key = Qnil;
+
+ if (SYMBOL_P(hash_or_key)) {
+ key = hash_or_key;
+ }
+ else if (RB_TYPE_P(hash_or_key, T_HASH)) {
+ hash = hash_or_key;
+ }
+ else {
+ rb_bug("gc_info_decode: non-hash or symbol given");
+ }
+
+#define SET(name, attr) \
+ if (key == ID2SYM(rb_intern_const(#name))) \
+ return (attr); \
+ else if (hash != Qnil) \
+ rb_hash_aset(hash, ID2SYM(rb_intern_const(#name)), (attr));
+
+ /* Hack to get StackProf working because it calls rb_gc_latest_gc_info with
+ * the :state key and expects a result. This always returns the :none state. */
+ SET(state, ID2SYM(rb_intern_const("none")));
+#undef SET
+
+ if (!NIL_P(key)) {
+ // Matched key should return above
+ return Qundef;
+ }
+
+ return hash;
+}
+
+enum gc_stat_sym {
+ gc_stat_sym_count,
+ gc_stat_sym_moving_gc_count,
+ gc_stat_sym_time,
+ gc_stat_sym_total_allocated_objects,
+ gc_stat_sym_total_bytes,
+ gc_stat_sym_used_bytes,
+ gc_stat_sym_free_bytes,
+ gc_stat_sym_starting_heap_address,
+ gc_stat_sym_last_heap_address,
+ gc_stat_sym_weak_references_count,
+ gc_stat_sym_last
+};
+
+static VALUE gc_stat_symbols[gc_stat_sym_last];
+
+static void
+setup_gc_stat_symbols(void)
+{
+ if (gc_stat_symbols[0] == 0) {
+#define S(s) gc_stat_symbols[gc_stat_sym_##s] = ID2SYM(rb_intern_const(#s))
+ S(count);
+ S(moving_gc_count);
+ S(time);
+ S(total_allocated_objects);
+ S(total_bytes);
+ S(used_bytes);
+ S(free_bytes);
+ S(starting_heap_address);
+ S(last_heap_address);
+ S(weak_references_count);
+ }
+}
+
+VALUE
+rb_gc_impl_stat(void *objspace_ptr, VALUE hash_or_sym)
+{
+ struct objspace *objspace = objspace_ptr;
+ VALUE hash = Qnil, key = Qnil;
+
+ setup_gc_stat_symbols();
+
+ if (RB_TYPE_P(hash_or_sym, T_HASH)) {
+ hash = hash_or_sym;
+ }
+ else if (SYMBOL_P(hash_or_sym)) {
+ key = hash_or_sym;
+ }
+ else {
+ rb_bug("non-hash or symbol given");
+ }
+
+#define SET(name, attr) \
+ if (key == gc_stat_symbols[gc_stat_sym_##name]) \
+ return SIZET2NUM(attr); \
+ else if (hash != Qnil) \
+ rb_hash_aset(hash, gc_stat_symbols[gc_stat_sym_##name], SIZET2NUM(attr));
+
+ SET(count, objspace->gc_count);
+ SET(moving_gc_count, objspace->moving_gc_count);
+ SET(time, objspace->total_gc_time / (1000 * 1000));
+ SET(total_allocated_objects, objspace->total_allocated_objects);
+ SET(total_bytes, mmtk_total_bytes());
+ SET(used_bytes, mmtk_used_bytes());
+ SET(free_bytes, mmtk_free_bytes());
+ SET(starting_heap_address, (size_t)mmtk_starting_heap_address());
+ SET(last_heap_address, (size_t)mmtk_last_heap_address());
+ SET(weak_references_count, mmtk_weak_references_count());
+#undef SET
+
+ if (!NIL_P(key)) {
+ // Matched key should return above
+ return Qundef;
+ }
+
+ return hash;
+}
+
+VALUE
+rb_gc_impl_stat_heap(void *objspace_ptr, VALUE heap_name, VALUE hash_or_sym)
+{
+ if (FIXNUM_P(heap_name) && SYMBOL_P(hash_or_sym)) {
+ int heap_idx = FIX2INT(heap_name);
+ if (heap_idx < 0 || heap_idx >= MMTK_HEAP_COUNT) {
+ rb_raise(rb_eArgError, "size pool index out of range");
+ }
+
+ if (hash_or_sym == ID2SYM(rb_intern("slot_size"))) {
+ return SIZET2NUM(heap_sizes[heap_idx]);
+ }
+
+ return Qundef;
+ }
+
+ if (RB_TYPE_P(hash_or_sym, T_HASH)) {
+ return hash_or_sym;
+ }
+
+ return Qundef;
+}
+
+// Miscellaneous
+
+#define RB_GC_OBJECT_METADATA_ENTRY_COUNT 1
+static struct rb_gc_object_metadata_entry object_metadata_entries[RB_GC_OBJECT_METADATA_ENTRY_COUNT + 1];
+
+struct rb_gc_object_metadata_entry *
+rb_gc_impl_object_metadata(void *objspace_ptr, VALUE obj)
+{
+ static ID ID_object_id;
+
+ if (!ID_object_id) {
+#define I(s) ID_##s = rb_intern(#s);
+ I(object_id);
+#undef I
+ }
+
+ size_t n = 0;
+
+#define SET_ENTRY(na, v) do { \
+ MMTK_ASSERT(n <= RB_GC_OBJECT_METADATA_ENTRY_COUNT); \
+ object_metadata_entries[n].name = ID_##na; \
+ object_metadata_entries[n].val = v; \
+ n++; \
+} while (0)
+
+ if (rb_obj_id_p(obj)) SET_ENTRY(object_id, rb_obj_id(obj));
+
+ object_metadata_entries[n].name = 0;
+ object_metadata_entries[n].val = 0;
+
+ return object_metadata_entries;
+}
+
+bool
+rb_gc_impl_pointer_to_heap_p(void *objspace_ptr, const void *ptr)
+{
+ if (ptr == NULL) return false;
+ if ((uintptr_t)ptr % sizeof(void*) != 0) return false;
+ return mmtk_is_mmtk_object((MMTk_Address)ptr);
+}
+
+bool
+rb_gc_impl_garbage_object_p(void *objspace_ptr, VALUE obj)
+{
+ return false;
+}
+
+void rb_gc_impl_set_event_hook(void *objspace_ptr, const rb_event_flag_t event) { }
+
+void
+rb_gc_impl_copy_attributes(void *objspace_ptr, VALUE dest, VALUE obj)
+{
+ if (mmtk_object_wb_unprotected_p((MMTk_ObjectReference)obj)) {
+ rb_gc_impl_writebarrier_unprotect(objspace_ptr, dest);
+ }
+
+ rb_gc_impl_copy_finalizer(objspace_ptr, dest, obj);
+}
+
+// GC Identification
+
+const char *
+rb_gc_impl_active_gc_name(void)
+{
+ return "mmtk";
+}
diff --git a/gc/mmtk/mmtk.h b/gc/mmtk/mmtk.h
new file mode 100644
index 0000000000..b11e2873e3
--- /dev/null
+++ b/gc/mmtk/mmtk.h
@@ -0,0 +1,175 @@
+#ifndef MMTK_H
+#define MMTK_H
+
+/* Warning, this file is autogenerated by cbindgen from the mmtk-ruby repository. Don't modify this manually. */
+
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef struct MMTk_Builder MMTk_Builder;
+typedef struct MMTk_Mutator MMTk_Mutator;
+
+typedef struct MMTk_ractor_cache *MMTk_VMThread;
+typedef struct MMTk_ractor_cache *MMTk_VMMutatorThread;
+typedef struct MMTk_GCThreadTLS *MMTk_VMWorkerThread;
+typedef void *MMTk_Address;
+typedef void *MMTk_ObjectReference;
+typedef void *MMTk_NullableObjectReference;
+typedef uint32_t MMTk_AllocationSemantics;
+
+typedef struct MMTk_BumpPointer {
+ uintptr_t cursor;
+ uintptr_t limit;
+} MMTk_BumpPointer;
+
+
+#define MMTk_OBJREF_OFFSET 8
+
+#define MMTk_MIN_OBJ_ALIGN 8
+
+#define MMTk_GC_THREAD_KIND_WORKER 1
+
+typedef struct MMTk_RubyBindingOptions {
+ size_t suffix_size;
+} MMTk_RubyBindingOptions;
+
+typedef MMTk_ObjectReference (*MMTk_ObjectClosureFunction)(void*, void*, MMTk_ObjectReference, bool);
+
+typedef struct MMTk_ObjectClosure {
+ /**
+ * The function to be called from C.
+ */
+ MMTk_ObjectClosureFunction c_function;
+ /**
+ * The pointer to the Rust-level closure object.
+ */
+ void *rust_closure;
+} MMTk_ObjectClosure;
+
+typedef struct MMTk_GCThreadTLS {
+ int kind;
+ void *gc_context;
+ struct MMTk_ObjectClosure object_closure;
+} MMTk_GCThreadTLS;
+
+typedef struct MMTk_RubyUpcalls {
+ void (*init_gc_worker_thread)(struct MMTk_GCThreadTLS *gc_worker_tls);
+ bool (*is_mutator)(void);
+ void (*stop_the_world)(void);
+ void (*resume_mutators)(bool gc_may_move);
+ void (*block_for_gc)(MMTk_VMMutatorThread tls);
+ void (*before_updating_jit_code)(void);
+ void (*after_updating_jit_code)(void);
+ size_t (*number_of_mutators)(void);
+ void (*get_mutators)(void (*visit_mutator)(MMTk_Mutator*, void*), void *data);
+ void (*scan_gc_roots)(void);
+ void (*scan_objspace)(void);
+ void (*move_obj_during_marking)(MMTk_ObjectReference from, MMTk_ObjectReference to);
+ void (*update_object_references)(MMTk_ObjectReference object);
+ void (*call_gc_mark_children)(MMTk_ObjectReference object);
+ void (*handle_weak_references)(MMTk_ObjectReference object, bool moving);
+ void (*call_obj_free)(MMTk_ObjectReference object);
+ size_t (*vm_live_bytes)(void);
+ void (*update_global_tables)(int tbl_idx, bool moving);
+ int (*global_tables_count)(void);
+ void (*update_finalizer_table)(void);
+ bool (*special_const_p)(MMTk_ObjectReference object);
+ void (*mutator_thread_panic_handler)(void);
+ void (*gc_thread_panic_handler)(void);
+} MMTk_RubyUpcalls;
+
+typedef struct MMTk_RawVecOfObjRef {
+ MMTk_ObjectReference *ptr;
+ size_t len;
+ size_t capa;
+} MMTk_RawVecOfObjRef;
+
+bool mmtk_is_live_object(MMTk_ObjectReference object);
+
+bool mmtk_is_reachable(MMTk_ObjectReference object);
+
+MMTk_Builder *mmtk_builder_default(void);
+
+void mmtk_init_binding(MMTk_Builder *builder,
+ const struct MMTk_RubyBindingOptions *binding_options,
+ const struct MMTk_RubyUpcalls *upcalls);
+
+void mmtk_initialize_collection(MMTk_VMThread tls);
+
+MMTk_Mutator *mmtk_bind_mutator(MMTk_VMMutatorThread tls);
+
+MMTk_BumpPointer *mmtk_get_bump_pointer_allocator(MMTk_Mutator *m);
+
+void mmtk_destroy_mutator(MMTk_Mutator *mutator);
+
+void mmtk_handle_user_collection_request(MMTk_VMMutatorThread tls, bool force, bool exhaustive);
+
+void mmtk_set_gc_enabled(bool enable);
+
+bool mmtk_gc_enabled_p(void);
+
+MMTk_Address mmtk_alloc(MMTk_Mutator *mutator,
+ size_t size,
+ size_t align,
+ size_t offset,
+ MMTk_AllocationSemantics semantics);
+
+void mmtk_post_alloc(MMTk_Mutator *mutator,
+ MMTk_ObjectReference refer,
+ size_t bytes,
+ MMTk_AllocationSemantics semantics);
+
+void mmtk_add_obj_free_candidates(const MMTk_ObjectReference *objects,
+ size_t count,
+ bool can_parallel_free);
+
+void mmtk_declare_weak_references(MMTk_ObjectReference object);
+
+bool mmtk_weak_references_alive_p(MMTk_ObjectReference object);
+
+size_t mmtk_weak_references_count(void);
+
+void mmtk_register_pinning_obj(MMTk_ObjectReference obj);
+
+void mmtk_object_reference_write_post(MMTk_Mutator *mutator, MMTk_ObjectReference object);
+
+void mmtk_register_wb_unprotected_object(MMTk_ObjectReference object);
+
+bool mmtk_object_wb_unprotected_p(MMTk_ObjectReference object);
+
+void mmtk_enumerate_objects(void (*callback)(MMTk_ObjectReference, void*), void *data);
+
+struct MMTk_RawVecOfObjRef mmtk_get_all_obj_free_candidates(void);
+
+void mmtk_free_raw_vec_of_obj_ref(struct MMTk_RawVecOfObjRef raw_vec);
+
+void mmtk_before_fork(void);
+
+void mmtk_after_fork(MMTk_VMThread tls);
+
+size_t mmtk_total_bytes(void);
+
+size_t mmtk_used_bytes(void);
+
+size_t mmtk_free_bytes(void);
+
+MMTk_Address mmtk_starting_heap_address(void);
+
+MMTk_Address mmtk_last_heap_address(void);
+
+size_t mmtk_worker_count(void);
+
+const uint8_t *mmtk_plan(void);
+
+const uint8_t *mmtk_heap_mode(void);
+
+size_t mmtk_heap_min(void);
+
+size_t mmtk_heap_max(void);
+
+bool mmtk_is_mmtk_object(MMTk_Address addr);
+
+#endif /* MMTK_H */
diff --git a/gc/mmtk/src/abi.rs b/gc/mmtk/src/abi.rs
new file mode 100644
index 0000000000..30890e0853
--- /dev/null
+++ b/gc/mmtk/src/abi.rs
@@ -0,0 +1,335 @@
+use crate::api::RubyMutator;
+use crate::extra_assert;
+use crate::Ruby;
+use libc::c_int;
+use mmtk::scheduler::GCWorker;
+use mmtk::util::Address;
+use mmtk::util::ObjectReference;
+use mmtk::util::VMMutatorThread;
+use mmtk::util::VMWorkerThread;
+
+// For the C binding
+pub const OBJREF_OFFSET: usize = 8;
+pub const MIN_OBJ_ALIGN: usize = 8; // Even on 32-bit machine. A Ruby object is at least 40 bytes large.
+
+pub const GC_THREAD_KIND_WORKER: libc::c_int = 1;
+
+const HIDDEN_SIZE_MASK: usize = 0x0000FFFFFFFFFFFF;
+
+// An opaque type for the C counterpart.
+#[allow(non_camel_case_types)]
+pub struct st_table;
+
+#[repr(C)]
+pub struct HiddenHeader {
+ pub prefix: usize,
+}
+
+impl HiddenHeader {
+ #[inline(always)]
+ pub fn is_sane(&self) -> bool {
+ self.prefix & !HIDDEN_SIZE_MASK == 0
+ }
+
+ #[inline(always)]
+ fn assert_sane(&self) {
+ extra_assert!(
+ self.is_sane(),
+ "Hidden header is corrupted: {:x}",
+ self.prefix
+ );
+ }
+
+ pub fn payload_size(&self) -> usize {
+ self.assert_sane();
+ self.prefix & HIDDEN_SIZE_MASK
+ }
+}
+
+/// Provide convenient methods for accessing Ruby objects.
+/// TODO: Wrap C functions in `RubyUpcalls` as Rust-friendly methods.
+pub struct RubyObjectAccess {
+ objref: ObjectReference,
+}
+
+impl RubyObjectAccess {
+ pub fn from_objref(objref: ObjectReference) -> Self {
+ Self { objref }
+ }
+
+ pub fn obj_start(&self) -> Address {
+ self.objref.to_raw_address().sub(Self::prefix_size())
+ }
+
+ pub fn payload_addr(&self) -> Address {
+ self.objref.to_raw_address()
+ }
+
+ pub fn suffix_addr(&self) -> Address {
+ self.objref.to_raw_address().add(self.payload_size())
+ }
+
+ pub fn obj_end(&self) -> Address {
+ self.suffix_addr() + Self::suffix_size()
+ }
+
+ fn hidden_header(&self) -> &'static HiddenHeader {
+ unsafe { self.obj_start().as_ref() }
+ }
+
+ #[allow(unused)] // Maybe we need to mutate the hidden header in the future.
+ fn hidden_header_mut(&self) -> &'static mut HiddenHeader {
+ unsafe { self.obj_start().as_mut_ref() }
+ }
+
+ pub fn payload_size(&self) -> usize {
+ self.hidden_header().payload_size()
+ }
+
+ fn flags_field(&self) -> Address {
+ self.objref.to_raw_address()
+ }
+
+ pub fn load_flags(&self) -> usize {
+ unsafe { self.flags_field().load::<usize>() }
+ }
+
+ pub fn prefix_size() -> usize {
+ // Currently, a hidden size field of word size is placed before each object.
+ OBJREF_OFFSET
+ }
+
+ pub fn suffix_size() -> usize {
+ // In RACTOR_CHECK_MODE, Ruby hides a field after each object to hold the Ractor ID.
+ unsafe { crate::BINDING_FAST.suffix_size }
+ }
+
+ pub fn object_size(&self) -> usize {
+ Self::prefix_size() + self.payload_size() + Self::suffix_size()
+ }
+}
+
+type ObjectClosureFunction =
+ extern "C" fn(*mut libc::c_void, *mut libc::c_void, ObjectReference, bool) -> ObjectReference;
+
+#[repr(C)]
+pub struct ObjectClosure {
+ /// The function to be called from C.
+ pub c_function: ObjectClosureFunction,
+ /// The pointer to the Rust-level closure object.
+ pub rust_closure: *mut libc::c_void,
+}
+
+impl Default for ObjectClosure {
+ fn default() -> Self {
+ Self {
+ c_function: THE_UNREGISTERED_CLOSURE_FUNC,
+ rust_closure: std::ptr::null_mut(),
+ }
+ }
+}
+
+/// Rust doesn't require function items to have a unique address.
+/// We therefore force using this particular constant.
+///
+/// See: https://rust-lang.github.io/rust-clippy/master/index.html#fn_address_comparisons
+const THE_UNREGISTERED_CLOSURE_FUNC: ObjectClosureFunction = ObjectClosure::c_function_unregistered;
+
+impl ObjectClosure {
+ /// Set this ObjectClosure temporarily to `visit_object`, and execute `f`. During the execution of
+ /// `f`, the Ruby VM may call this ObjectClosure. When the Ruby VM calls this ObjectClosure,
+ /// it effectively calls `visit_object`.
+ ///
+ /// This method is intended to run Ruby VM code in `f` with temporarily modified behavior of
+ /// `rb_gc_mark`, `rb_gc_mark_movable` and `rb_gc_location`
+ ///
+ /// Both `f` and `visit_object` may access and modify local variables in the environment where
+ /// `set_temporarily_and_run_code` called.
+ ///
+ /// Note that this function is not reentrant. Don't call this function in either `callback` or
+ /// `f`.
+ pub fn set_temporarily_and_run_code<'env, T, F1, F2>(
+ &mut self,
+ mut visit_object: F1,
+ f: F2,
+ ) -> T
+ where
+ F1: 'env + FnMut(&'static mut GCWorker<Ruby>, ObjectReference, bool) -> ObjectReference,
+ F2: 'env + FnOnce() -> T,
+ {
+ debug_assert!(
+ std::ptr::fn_addr_eq(self.c_function, THE_UNREGISTERED_CLOSURE_FUNC),
+ "set_temporarily_and_run_code is recursively called."
+ );
+ self.c_function = Self::c_function_registered::<F1>;
+ self.rust_closure = &mut visit_object as *mut F1 as *mut libc::c_void;
+ let result = f();
+ *self = Default::default();
+ result
+ }
+
+ extern "C" fn c_function_registered<F>(
+ rust_closure: *mut libc::c_void,
+ worker: *mut libc::c_void,
+ object: ObjectReference,
+ pin: bool,
+ ) -> ObjectReference
+ where
+ F: FnMut(&'static mut GCWorker<Ruby>, ObjectReference, bool) -> ObjectReference,
+ {
+ let rust_closure = unsafe { &mut *(rust_closure as *mut F) };
+ let worker = unsafe { &mut *(worker as *mut GCWorker<Ruby>) };
+ rust_closure(worker, object, pin)
+ }
+
+ extern "C" fn c_function_unregistered(
+ _rust_closure: *mut libc::c_void,
+ worker: *mut libc::c_void,
+ object: ObjectReference,
+ pin: bool,
+ ) -> ObjectReference {
+ let worker = unsafe { &mut *(worker as *mut GCWorker<Ruby>) };
+ panic!(
+ "object_closure is not set. worker ordinal: {}, object: {}, pin: {}",
+ worker.ordinal, object, pin
+ );
+ }
+}
+
+#[repr(C)]
+pub struct GCThreadTLS {
+ pub kind: libc::c_int,
+ pub gc_context: *mut libc::c_void,
+ pub object_closure: ObjectClosure,
+}
+
+impl GCThreadTLS {
+ fn new(kind: libc::c_int, gc_context: *mut libc::c_void) -> Self {
+ Self {
+ kind,
+ gc_context,
+ object_closure: Default::default(),
+ }
+ }
+
+ pub fn for_worker(gc_context: *mut GCWorker<Ruby>) -> Self {
+ Self::new(GC_THREAD_KIND_WORKER, gc_context as *mut libc::c_void)
+ }
+
+ pub fn from_vwt(vwt: VMWorkerThread) -> *mut GCThreadTLS {
+ unsafe { std::mem::transmute(vwt) }
+ }
+
+ /// Cast a pointer to `GCThreadTLS` to a ref, with assertion for null pointer.
+ ///
+ /// # Safety
+ ///
+ /// Has undefined behavior if `ptr` is invalid.
+ pub unsafe fn check_cast(ptr: *mut GCThreadTLS) -> &'static mut GCThreadTLS {
+ assert!(!ptr.is_null());
+ let result = unsafe { &mut *ptr };
+ debug_assert!({
+ let kind = result.kind;
+ kind == GC_THREAD_KIND_WORKER
+ });
+ result
+ }
+
+ /// Cast a pointer to `VMWorkerThread` to a ref, with assertion for null pointer.
+ ///
+ /// # Safety
+ ///
+ /// Has undefined behavior if `ptr` is invalid.
+ pub unsafe fn from_vwt_check(vwt: VMWorkerThread) -> &'static mut GCThreadTLS {
+ let ptr = Self::from_vwt(vwt);
+ unsafe { Self::check_cast(ptr) }
+ }
+
+ #[allow(clippy::not_unsafe_ptr_arg_deref)] // `transmute` does not dereference pointer
+ pub fn to_vwt(ptr: *mut Self) -> VMWorkerThread {
+ unsafe { std::mem::transmute(ptr) }
+ }
+
+ pub fn worker<'w>(&mut self) -> &'w mut GCWorker<Ruby> {
+ // NOTE: The returned ref points to the worker which does not have the same lifetime as self.
+ assert!(self.kind == GC_THREAD_KIND_WORKER);
+ unsafe { &mut *(self.gc_context as *mut GCWorker<Ruby>) }
+ }
+}
+
+#[repr(C)]
+#[derive(Clone)]
+pub struct RawVecOfObjRef {
+ pub ptr: *mut ObjectReference,
+ pub len: usize,
+ pub capa: usize,
+}
+
+impl RawVecOfObjRef {
+ pub fn from_vec(vec: Vec<ObjectReference>) -> RawVecOfObjRef {
+ // Note: Vec::into_raw_parts is unstable. We implement it manually.
+ let mut vec = std::mem::ManuallyDrop::new(vec);
+ let (ptr, len, capa) = (vec.as_mut_ptr(), vec.len(), vec.capacity());
+
+ RawVecOfObjRef { ptr, len, capa }
+ }
+
+ /// # Safety
+ ///
+ /// This function turns raw pointer into a Vec without check.
+ pub unsafe fn into_vec(self) -> Vec<ObjectReference> {
+ unsafe { Vec::from_raw_parts(self.ptr, self.len, self.capa) }
+ }
+}
+
+impl From<Vec<ObjectReference>> for RawVecOfObjRef {
+ fn from(v: Vec<ObjectReference>) -> Self {
+ Self::from_vec(v)
+ }
+}
+
+#[repr(C)]
+#[derive(Clone)]
+pub struct RubyBindingOptions {
+ pub suffix_size: usize,
+}
+
+#[repr(C)]
+#[derive(Clone)]
+pub struct RubyUpcalls {
+ pub init_gc_worker_thread: extern "C" fn(gc_worker_tls: *mut GCThreadTLS),
+ pub is_mutator: extern "C" fn() -> bool,
+ pub stop_the_world: extern "C" fn(),
+ pub resume_mutators: extern "C" fn(gc_may_move: bool),
+ pub block_for_gc: extern "C" fn(tls: VMMutatorThread),
+ pub before_updating_jit_code: extern "C" fn(),
+ pub after_updating_jit_code: extern "C" fn(),
+ pub number_of_mutators: extern "C" fn() -> usize,
+ pub get_mutators: extern "C" fn(
+ visit_mutator: extern "C" fn(*mut RubyMutator, *mut libc::c_void),
+ data: *mut libc::c_void,
+ ),
+ pub scan_gc_roots: extern "C" fn(),
+ pub scan_objspace: extern "C" fn(),
+ pub move_obj_during_marking: extern "C" fn(from: ObjectReference, to: ObjectReference),
+ pub update_object_references: extern "C" fn(object: ObjectReference),
+ pub call_gc_mark_children: extern "C" fn(object: ObjectReference),
+ pub handle_weak_references: extern "C" fn(object: ObjectReference, moving: bool),
+ pub call_obj_free: extern "C" fn(object: ObjectReference),
+ pub vm_live_bytes: extern "C" fn() -> usize,
+ pub update_global_tables: extern "C" fn(tbl_idx: c_int, moving: bool),
+ pub global_tables_count: extern "C" fn() -> c_int,
+ pub update_finalizer_table: extern "C" fn(),
+ pub special_const_p: extern "C" fn(object: ObjectReference) -> bool,
+ pub mutator_thread_panic_handler: extern "C" fn(),
+ pub gc_thread_panic_handler: extern "C" fn(),
+}
+
+unsafe impl Sync for RubyUpcalls {}
+
+#[repr(C)]
+#[derive(Clone)]
+pub struct HeapBounds {
+ pub start: *mut libc::c_void,
+ pub end: *mut libc::c_void,
+}
diff --git a/gc/mmtk/src/active_plan.rs b/gc/mmtk/src/active_plan.rs
new file mode 100644
index 0000000000..80372a7576
--- /dev/null
+++ b/gc/mmtk/src/active_plan.rs
@@ -0,0 +1,56 @@
+use std::collections::VecDeque;
+use std::marker::PhantomData;
+
+use crate::mmtk;
+use crate::upcalls;
+use crate::Ruby;
+use mmtk::util::opaque_pointer::*;
+use mmtk::vm::ActivePlan;
+use mmtk::Mutator;
+
+pub struct VMActivePlan {}
+
+impl ActivePlan<Ruby> for VMActivePlan {
+ fn number_of_mutators() -> usize {
+ (upcalls().number_of_mutators)()
+ }
+
+ fn is_mutator(_tls: VMThread) -> bool {
+ (upcalls().is_mutator)()
+ }
+
+ fn mutator(_tls: VMMutatorThread) -> &'static mut Mutator<Ruby> {
+ unimplemented!()
+ }
+
+ fn mutators<'a>() -> Box<dyn Iterator<Item = &'a mut Mutator<Ruby>> + 'a> {
+ let mut mutators = VecDeque::new();
+ (upcalls().get_mutators)(
+ add_mutator_to_vec,
+ &mut mutators as *mut VecDeque<&mut Mutator<Ruby>> as _,
+ );
+
+ Box::new(RubyMutatorIterator {
+ mutators,
+ phantom_data: PhantomData,
+ })
+ }
+}
+
+extern "C" fn add_mutator_to_vec(mutator: *mut Mutator<Ruby>, mutators: *mut libc::c_void) {
+ let mutators = unsafe { &mut *(mutators as *mut VecDeque<*mut Mutator<Ruby>>) };
+ mutators.push_back(unsafe { &mut *mutator });
+}
+
+struct RubyMutatorIterator<'a> {
+ mutators: VecDeque<&'a mut Mutator<Ruby>>,
+ phantom_data: PhantomData<&'a ()>,
+}
+
+impl<'a> Iterator for RubyMutatorIterator<'a> {
+ type Item = &'a mut Mutator<Ruby>;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ self.mutators.pop_front()
+ }
+}
diff --git a/gc/mmtk/src/api.rs b/gc/mmtk/src/api.rs
new file mode 100644
index 0000000000..c0540fe0c8
--- /dev/null
+++ b/gc/mmtk/src/api.rs
@@ -0,0 +1,551 @@
+// Functions in this module are unsafe for one reason:
+// They are called by C functions and they need to pass raw pointers to Rust.
+#![allow(clippy::missing_safety_doc)]
+
+use mmtk::util::alloc::BumpPointer;
+use mmtk::util::alloc::ImmixAllocator;
+use mmtk::util::conversions;
+use mmtk::util::options::PlanSelector;
+use std::str::FromStr;
+use std::sync::atomic::Ordering;
+
+use crate::abi::RawVecOfObjRef;
+use crate::abi::RubyBindingOptions;
+use crate::abi::RubyUpcalls;
+use crate::binding;
+use crate::binding::RubyBinding;
+use crate::heap::CpuHeapTriggerConfig;
+use crate::heap::RubyHeapTriggerConfig;
+use crate::heap::CPU_HEAP_TRIGGER_CONFIG;
+use crate::heap::RUBY_HEAP_TRIGGER_CONFIG;
+use crate::mmtk;
+use crate::utils::default_heap_max;
+use crate::utils::parse_capacity;
+use crate::Ruby;
+use crate::RubySlot;
+use mmtk::memory_manager;
+use mmtk::memory_manager::mmtk_init;
+use mmtk::util::constants::MIN_OBJECT_SIZE;
+use mmtk::util::options::GCTriggerSelector;
+use mmtk::util::Address;
+use mmtk::util::ObjectReference;
+use mmtk::util::VMMutatorThread;
+use mmtk::util::VMThread;
+use mmtk::AllocationSemantics;
+use mmtk::MMTKBuilder;
+use mmtk::Mutator;
+
+pub type RubyMutator = Mutator<Ruby>;
+
+#[no_mangle]
+pub extern "C" fn mmtk_is_live_object(object: ObjectReference) -> bool {
+ memory_manager::is_live_object(object)
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_is_reachable(object: ObjectReference) -> bool {
+ object.is_reachable()
+}
+
+// =============== Bootup ===============
+
+fn parse_env_var_with<T, F: FnOnce(&str) -> Option<T>>(key: &str, parse: F) -> Option<T> {
+ let val = match std::env::var(key) {
+ Ok(val) => val,
+ Err(std::env::VarError::NotPresent) => return None,
+ Err(std::env::VarError::NotUnicode(os_string)) => {
+ eprintln!("[FATAL] Invalid {key} {os_string:?}");
+ std::process::exit(1);
+ }
+ };
+
+ let parsed = parse(&val).unwrap_or_else(|| {
+ eprintln!("[FATAL] Invalid {key} {val}");
+ std::process::exit(1);
+ });
+
+ Some(parsed)
+}
+
+fn parse_env_var<T: FromStr>(key: &str) -> Option<T> {
+ parse_env_var_with(key, |s| s.parse().ok())
+}
+
+fn mmtk_builder_default_parse_threads() -> Option<usize> {
+ parse_env_var("MMTK_THREADS")
+}
+
+fn mmtk_builder_default_parse_heap_min() -> usize {
+ const DEFAULT_HEAP_MIN: usize = 1 << 20;
+ parse_env_var_with("MMTK_HEAP_MIN", parse_capacity).unwrap_or(DEFAULT_HEAP_MIN)
+}
+
+fn mmtk_builder_default_parse_heap_max() -> usize {
+ parse_env_var_with("MMTK_HEAP_MAX", parse_capacity).unwrap_or_else(default_heap_max)
+}
+
+fn parse_float_env_var(key: &str, default: f64, min: f64, max: f64) -> f64 {
+ parse_env_var_with(key, |s| {
+ let mut float = f64::from_str(s).unwrap_or(default);
+
+ if float <= min {
+ eprintln!(
+ "{key} has value {float} which must be greater than {min}, using default instead"
+ );
+ float = default;
+ }
+
+ if float >= max {
+ eprintln!(
+ "{key} has value {float} which must be less than {max}, using default instead"
+ );
+ float = default;
+ }
+
+ Some(float)
+ })
+ .unwrap_or(default)
+}
+
+fn mmtk_builder_default_parse_heap_mode(heap_min: usize, heap_max: usize) -> GCTriggerSelector {
+ let make_fixed = || GCTriggerSelector::FixedHeapSize(heap_max);
+ let make_dynamic = || GCTriggerSelector::DynamicHeapSize(heap_min, heap_max);
+
+ parse_env_var_with("MMTK_HEAP_MODE", |s| match s {
+ "fixed" => Some(make_fixed()),
+ "dynamic" => Some(make_dynamic()),
+ "ruby" => {
+ let min_ratio = parse_float_env_var("RUBY_GC_HEAP_FREE_SLOTS_MIN_RATIO", 0.2, 0.0, 1.0);
+ let goal_ratio =
+ parse_float_env_var("RUBY_GC_HEAP_FREE_SLOTS_GOAL_RATIO", 0.4, min_ratio, 1.0);
+ let max_ratio =
+ parse_float_env_var("RUBY_GC_HEAP_FREE_SLOTS_MAX_RATIO", 0.65, goal_ratio, 1.0);
+
+ crate::heap::RUBY_HEAP_TRIGGER_CONFIG
+ .set(RubyHeapTriggerConfig {
+ min_heap_pages: conversions::bytes_to_pages_up(heap_min),
+ max_heap_pages: conversions::bytes_to_pages_up(heap_max),
+ heap_pages_min_ratio: min_ratio,
+ heap_pages_goal_ratio: goal_ratio,
+ heap_pages_max_ratio: max_ratio,
+ })
+ .unwrap_or_else(|_| panic!("RUBY_HEAP_TRIGGER_CONFIG is already set"));
+
+ Some(GCTriggerSelector::Delegated)
+ }
+ "cpu" => {
+ // CPU-overhead-driven heap sizing based on Tavakolisomeh et al.,
+ // "Heap Size Adjustment with CPU Control", MPLR '23.
+ //
+ // Target is expressed as a percentage (0, 100) via
+ // `MMTK_GC_CPU_TARGET`. The paper recommends 15 for ZGC (a
+ // concurrent collector); we default to 5 for MMTk-Ruby. With
+ // MMTk's stop-the-world Immix, every percent of GC CPU is also
+ // a percent of wall-clock the mutator is blocked on, so a much
+ // smaller budget is appropriate. An empirical sweep across
+ // ruby-bench (railsbench, lobsters, psych-load, liquid-render,
+ // lee) found target=5 to be Pareto-optimal: ~6% geomean speedup
+ // vs. the `ruby` heap mode with effectively identical geomean
+ // peak RSS.
+ let target_percent = parse_float_env_var("MMTK_GC_CPU_TARGET", 5.0, 0.0, 100.0);
+ let window_size = parse_env_var::<usize>("MMTK_GC_CPU_WINDOW").unwrap_or(3);
+ let window_size = window_size.max(1);
+
+ let min_heap_pages = conversions::bytes_to_pages_up(heap_min);
+ let max_heap_pages = conversions::bytes_to_pages_up(heap_max);
+ // Start at the min heap size, as the other delegated triggers do.
+ // The control loop will adjust from here after the first GC cycle.
+ let initial_heap_pages = min_heap_pages;
+
+ CPU_HEAP_TRIGGER_CONFIG
+ .set(CpuHeapTriggerConfig {
+ min_heap_pages,
+ max_heap_pages,
+ initial_heap_pages,
+ target_gc_cpu: target_percent / 100.0,
+ window_size,
+ })
+ .unwrap_or_else(|_| panic!("CPU_HEAP_TRIGGER_CONFIG is already set"));
+
+ Some(GCTriggerSelector::Delegated)
+ }
+ _ => None,
+ })
+ .unwrap_or_else(make_dynamic)
+}
+
+fn mmtk_builder_default_parse_plan() -> PlanSelector {
+ parse_env_var_with("MMTK_PLAN", |s| match s {
+ "NoGC" => Some(PlanSelector::NoGC),
+ "MarkSweep" => Some(PlanSelector::MarkSweep),
+ "Immix" => Some(PlanSelector::Immix),
+ _ => None,
+ })
+ .unwrap_or(PlanSelector::Immix)
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_builder_default() -> *mut MMTKBuilder {
+ let mut builder = MMTKBuilder::new_no_env_vars();
+ builder.options.no_finalizer.set(true);
+
+ if let Some(threads) = mmtk_builder_default_parse_threads() {
+ if !builder.options.threads.set(threads) {
+ // MMTk will validate it and reject 0.
+ eprintln!("[FATAL] Failed to set the number of MMTk threads to {threads}");
+ std::process::exit(1);
+ }
+ }
+
+ let heap_min = mmtk_builder_default_parse_heap_min();
+
+ let heap_max = mmtk_builder_default_parse_heap_max();
+
+ if heap_min >= heap_max {
+ eprintln!("[FATAL] MMTK_HEAP_MIN({heap_min}) >= MMTK_HEAP_MAX({heap_max})");
+ std::process::exit(1);
+ }
+
+ builder
+ .options
+ .gc_trigger
+ .set(mmtk_builder_default_parse_heap_mode(heap_min, heap_max));
+
+ builder.options.plan.set(mmtk_builder_default_parse_plan());
+
+ Box::into_raw(Box::new(builder))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mmtk_init_binding(
+ builder: *mut MMTKBuilder,
+ binding_options: *const RubyBindingOptions,
+ upcalls: *const RubyUpcalls,
+) {
+ crate::MUTATOR_THREAD_PANIC_HANDLER
+ .set((unsafe { (*upcalls).clone() }).mutator_thread_panic_handler)
+ .unwrap_or_else(|_| panic!("MUTATOR_THREAD_PANIC_HANDLER is already initialized"));
+
+ crate::set_panic_hook();
+
+ let builder: Box<MMTKBuilder> = unsafe { Box::from_raw(builder) };
+ let binding_options = unsafe { (*binding_options).clone() };
+ let mmtk_boxed = mmtk_init(&builder);
+ let mmtk_static = Box::leak(Box::new(mmtk_boxed));
+
+ let mut binding = RubyBinding::new(mmtk_static, &binding_options, upcalls);
+ binding
+ .weak_proc
+ .init_parallel_obj_free_candidates(memory_manager::num_of_workers(binding.mmtk));
+
+ crate::BINDING
+ .set(binding)
+ .unwrap_or_else(|_| panic!("Binding is already initialized"));
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_initialize_collection(tls: VMThread) {
+ memory_manager::initialize_collection(mmtk(), tls)
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_bind_mutator(tls: VMMutatorThread) -> *mut RubyMutator {
+ Box::into_raw(memory_manager::bind_mutator(mmtk(), tls))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mmtk_get_bump_pointer_allocator(m: *mut RubyMutator) -> *mut BumpPointer {
+ match *crate::BINDING.get().unwrap().mmtk.get_options().plan {
+ PlanSelector::Immix => {
+ let mutator: &mut Mutator<Ruby> = unsafe { &mut *m };
+ let allocator =
+ unsafe { mutator.allocator_mut(mmtk::util::alloc::AllocatorSelector::Immix(0)) };
+
+ if let Some(immix_allocator) = allocator.downcast_mut::<ImmixAllocator<Ruby>>() {
+ &mut immix_allocator.bump_pointer as *mut BumpPointer
+ } else {
+ panic!("Failed to get bump pointer allocator");
+ }
+ }
+ _ => std::ptr::null_mut(),
+ }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mmtk_destroy_mutator(mutator: *mut RubyMutator) {
+ // notify mmtk-core about destroyed mutator
+ memory_manager::destroy_mutator(unsafe { &mut *mutator });
+ // turn the ptr back to a box, and let Rust properly reclaim it
+ let _ = unsafe { Box::from_raw(mutator) };
+}
+
+// =============== GC ===============
+
+#[no_mangle]
+pub extern "C" fn mmtk_handle_user_collection_request(
+ tls: VMMutatorThread,
+ force: bool,
+ exhaustive: bool,
+) {
+ crate::mmtk().handle_user_collection_request(tls, force, exhaustive);
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_set_gc_enabled(enable: bool) {
+ crate::CONFIGURATION
+ .gc_enabled
+ .store(enable, Ordering::Relaxed);
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_gc_enabled_p() -> bool {
+ crate::CONFIGURATION.gc_enabled.load(Ordering::Relaxed)
+}
+
+// =============== Object allocation ===============
+
+#[no_mangle]
+pub unsafe extern "C" fn mmtk_alloc(
+ mutator: *mut RubyMutator,
+ size: usize,
+ align: usize,
+ offset: usize,
+ semantics: AllocationSemantics,
+) -> Address {
+ let clamped_size = size.max(MIN_OBJECT_SIZE);
+ memory_manager::alloc::<Ruby>(
+ unsafe { &mut *mutator },
+ clamped_size,
+ align,
+ offset,
+ semantics,
+ )
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mmtk_post_alloc(
+ mutator: *mut RubyMutator,
+ refer: ObjectReference,
+ bytes: usize,
+ semantics: AllocationSemantics,
+) {
+ memory_manager::post_alloc::<Ruby>(unsafe { &mut *mutator }, refer, bytes, semantics)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mmtk_add_obj_free_candidates(
+ objects: *const ObjectReference,
+ count: usize,
+ can_parallel_free: bool,
+) {
+ let objects = unsafe { std::slice::from_raw_parts(objects, count) };
+ binding()
+ .weak_proc
+ .add_obj_free_candidates_batch(objects, can_parallel_free)
+}
+
+// =============== Weak references ===============
+
+#[no_mangle]
+pub extern "C" fn mmtk_declare_weak_references(object: ObjectReference) {
+ binding().weak_proc.add_weak_reference(object);
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_weak_references_alive_p(object: ObjectReference) -> bool {
+ object.is_reachable()
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_weak_references_count() -> usize {
+ binding().weak_proc.weak_references_count()
+}
+
+// =============== Compaction ===============
+
+#[no_mangle]
+pub extern "C" fn mmtk_register_pinning_obj(obj: ObjectReference) {
+ crate::binding().pinning_registry.register(obj);
+}
+
+// =============== Write barriers ===============
+
+#[no_mangle]
+pub unsafe extern "C" fn mmtk_object_reference_write_post(
+ mutator: *mut RubyMutator,
+ object: ObjectReference,
+) {
+ let ignored_slot = RubySlot::from_address(Address::ZERO);
+ let ignored_target = ObjectReference::from_raw_address(Address::ZERO);
+ mmtk::memory_manager::object_reference_write_post(
+ unsafe { &mut *mutator },
+ object,
+ ignored_slot,
+ ignored_target,
+ )
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_register_wb_unprotected_object(object: ObjectReference) {
+ crate::binding().register_wb_unprotected_object(object)
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_object_wb_unprotected_p(object: ObjectReference) -> bool {
+ crate::binding().object_wb_unprotected_p(object)
+}
+
+// =============== Heap walking ===============
+
+#[no_mangle]
+pub extern "C" fn mmtk_enumerate_objects(
+ callback: extern "C" fn(ObjectReference, *mut libc::c_void),
+ data: *mut libc::c_void,
+) {
+ crate::mmtk().enumerate_objects(|object| {
+ callback(object, data);
+ })
+}
+
+// =============== Finalizers ===============
+
+#[no_mangle]
+pub extern "C" fn mmtk_get_all_obj_free_candidates() -> RawVecOfObjRef {
+ let vec = binding().weak_proc.get_all_obj_free_candidates();
+ RawVecOfObjRef::from_vec(vec)
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_free_raw_vec_of_obj_ref(raw_vec: RawVecOfObjRef) {
+ unsafe { raw_vec.into_vec() };
+}
+
+// =============== Forking ===============
+
+#[no_mangle]
+pub extern "C" fn mmtk_before_fork() {
+ mmtk().prepare_to_fork();
+ binding().join_all_gc_threads();
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_after_fork(tls: VMThread) {
+ mmtk().after_fork(tls);
+}
+
+// =============== Statistics ===============
+
+#[no_mangle]
+pub extern "C" fn mmtk_total_bytes() -> usize {
+ memory_manager::total_bytes(mmtk())
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_used_bytes() -> usize {
+ memory_manager::used_bytes(mmtk())
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_free_bytes() -> usize {
+ memory_manager::free_bytes(mmtk())
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_starting_heap_address() -> Address {
+ memory_manager::starting_heap_address()
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_last_heap_address() -> Address {
+ memory_manager::last_heap_address()
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_worker_count() -> usize {
+ memory_manager::num_of_workers(mmtk())
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_plan() -> *const u8 {
+ static NO_GC: &[u8] = b"NoGC\0";
+ static MARK_SWEEP: &[u8] = b"MarkSweep\0";
+ static IMMIX: &[u8] = b"Immix\0";
+
+ match *crate::BINDING.get().unwrap().mmtk.get_options().plan {
+ PlanSelector::NoGC => NO_GC.as_ptr(),
+ PlanSelector::MarkSweep => MARK_SWEEP.as_ptr(),
+ PlanSelector::Immix => IMMIX.as_ptr(),
+ _ => panic!("Unknown plan"),
+ }
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_heap_mode() -> *const u8 {
+ static FIXED_HEAP: &[u8] = b"fixed\0";
+ static DYNAMIC_HEAP: &[u8] = b"dynamic\0";
+ static RUBY_HEAP: &[u8] = b"ruby\0";
+ static CPU_HEAP: &[u8] = b"cpu\0";
+
+ match *crate::BINDING.get().unwrap().mmtk.get_options().gc_trigger {
+ GCTriggerSelector::FixedHeapSize(_) => FIXED_HEAP.as_ptr(),
+ GCTriggerSelector::DynamicHeapSize(_, _) => DYNAMIC_HEAP.as_ptr(),
+ GCTriggerSelector::Delegated => {
+ // Two delegated triggers exist; disambiguate via the populated
+ // config singleton.
+ if CPU_HEAP_TRIGGER_CONFIG.get().is_some() {
+ CPU_HEAP.as_ptr()
+ } else {
+ RUBY_HEAP.as_ptr()
+ }
+ }
+ }
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_heap_min() -> usize {
+ match *crate::BINDING.get().unwrap().mmtk.get_options().gc_trigger {
+ GCTriggerSelector::FixedHeapSize(_) => 0,
+ GCTriggerSelector::DynamicHeapSize(min_size, _) => min_size,
+ GCTriggerSelector::Delegated => {
+ if let Some(cfg) = CPU_HEAP_TRIGGER_CONFIG.get() {
+ conversions::pages_to_bytes(cfg.min_heap_pages)
+ } else {
+ conversions::pages_to_bytes(
+ RUBY_HEAP_TRIGGER_CONFIG
+ .get()
+ .expect("RUBY_HEAP_TRIGGER_CONFIG not set")
+ .min_heap_pages,
+ )
+ }
+ }
+ }
+}
+
+#[no_mangle]
+pub extern "C" fn mmtk_heap_max() -> usize {
+ match *crate::BINDING.get().unwrap().mmtk.get_options().gc_trigger {
+ GCTriggerSelector::FixedHeapSize(max_size) => max_size,
+ GCTriggerSelector::DynamicHeapSize(_, max_size) => max_size,
+ GCTriggerSelector::Delegated => {
+ if let Some(cfg) = CPU_HEAP_TRIGGER_CONFIG.get() {
+ conversions::pages_to_bytes(cfg.max_heap_pages)
+ } else {
+ conversions::pages_to_bytes(
+ RUBY_HEAP_TRIGGER_CONFIG
+ .get()
+ .expect("RUBY_HEAP_TRIGGER_CONFIG not set")
+ .max_heap_pages,
+ )
+ }
+ }
+ }
+}
+
+// =============== Miscellaneous ===============
+
+#[no_mangle]
+pub extern "C" fn mmtk_is_mmtk_object(addr: Address) -> bool {
+ debug_assert!(!addr.is_zero());
+ debug_assert!(addr.is_aligned_to(mmtk::util::is_mmtk_object::VO_BIT_REGION_SIZE));
+ memory_manager::is_mmtk_object(addr).is_some()
+}
diff --git a/gc/mmtk/src/binding.rs b/gc/mmtk/src/binding.rs
new file mode 100644
index 0000000000..36d4a992fd
--- /dev/null
+++ b/gc/mmtk/src/binding.rs
@@ -0,0 +1,129 @@
+use std::collections::HashSet;
+use std::ffi::CString;
+use std::sync::atomic::AtomicBool;
+use std::sync::Mutex;
+use std::thread::JoinHandle;
+
+use mmtk::util::ObjectReference;
+use mmtk::MMTK;
+
+use crate::abi;
+use crate::abi::RubyBindingOptions;
+use crate::pinning_registry::PinningRegistry;
+use crate::weak_proc::WeakProcessor;
+use crate::Ruby;
+
+pub struct RubyBindingFast {
+ pub suffix_size: usize,
+}
+
+impl Default for RubyBindingFast {
+ fn default() -> Self {
+ Self::new()
+ }
+}
+
+impl RubyBindingFast {
+ pub const fn new() -> Self {
+ Self { suffix_size: 0 }
+ }
+}
+
+pub struct RubyConfiguration {
+ pub gc_enabled: AtomicBool,
+}
+
+impl Default for RubyConfiguration {
+ fn default() -> Self {
+ Self::new()
+ }
+}
+
+impl RubyConfiguration {
+ pub const fn new() -> Self {
+ Self {
+ // Mimic the old behavior when the gc_enabled flag was in mmtk-core.
+ // We may refactor it so that it is false by default.
+ gc_enabled: AtomicBool::new(true),
+ }
+ }
+}
+
+pub struct RubyBinding {
+ pub mmtk: &'static MMTK<Ruby>,
+ pub options: RubyBindingOptions,
+ pub upcalls: *const abi::RubyUpcalls,
+ pub plan_name: Mutex<Option<CString>>,
+ pub weak_proc: WeakProcessor,
+ pub pinning_registry: PinningRegistry,
+ pub gc_thread_join_handles: Mutex<Vec<JoinHandle<()>>>,
+ pub wb_unprotected_objects: Mutex<HashSet<ObjectReference>>,
+}
+
+unsafe impl Sync for RubyBinding {}
+unsafe impl Send for RubyBinding {}
+
+impl RubyBinding {
+ pub fn new(
+ mmtk: &'static MMTK<Ruby>,
+ binding_options: &RubyBindingOptions,
+ upcalls: *const abi::RubyUpcalls,
+ ) -> Self {
+ unsafe {
+ crate::BINDING_FAST.suffix_size = binding_options.suffix_size;
+ }
+
+ Self {
+ mmtk,
+ options: binding_options.clone(),
+ upcalls,
+ plan_name: Mutex::new(None),
+ weak_proc: WeakProcessor::new(),
+ pinning_registry: PinningRegistry::new(),
+ gc_thread_join_handles: Default::default(),
+ wb_unprotected_objects: Default::default(),
+ }
+ }
+
+ pub fn upcalls(&self) -> &'static abi::RubyUpcalls {
+ unsafe { &*self.upcalls as &'static abi::RubyUpcalls }
+ }
+
+ pub fn get_plan_name_c(&self) -> *const libc::c_char {
+ let mut plan_name = self.plan_name.lock().unwrap();
+ if plan_name.is_none() {
+ let name_string = format!("{:?}", *self.mmtk.get_options().plan);
+ let c_string = CString::new(name_string)
+ .unwrap_or_else(|e| panic!("Failed converting plan name to CString: {e}"));
+ *plan_name = Some(c_string);
+ }
+ plan_name.as_deref().unwrap().as_ptr()
+ }
+
+ pub fn join_all_gc_threads(&self) {
+ let handles = {
+ let mut guard = self.gc_thread_join_handles.lock().unwrap();
+ std::mem::take(&mut *guard)
+ };
+
+ debug!("Joining GC threads...");
+ let total = handles.len();
+ let mut joined = 0;
+ for handle in handles {
+ handle.join().unwrap();
+ joined += 1;
+ debug!("{joined}/{total} GC threads joined.");
+ }
+ }
+
+ pub fn register_wb_unprotected_object(&self, object: ObjectReference) {
+ debug!("Registering WB-unprotected object: {object}");
+ let mut objects = self.wb_unprotected_objects.lock().unwrap();
+ objects.insert(object);
+ }
+
+ pub fn object_wb_unprotected_p(&self, object: ObjectReference) -> bool {
+ let objects = self.wb_unprotected_objects.lock().unwrap();
+ objects.contains(&object)
+ }
+}
diff --git a/gc/mmtk/src/collection.rs b/gc/mmtk/src/collection.rs
new file mode 100644
index 0000000000..648efa4e27
--- /dev/null
+++ b/gc/mmtk/src/collection.rs
@@ -0,0 +1,122 @@
+use crate::abi::GCThreadTLS;
+
+use crate::api::RubyMutator;
+use crate::heap::CpuHeapTrigger;
+use crate::heap::RubyHeapTrigger;
+use crate::heap::CPU_HEAP_TRIGGER_CONFIG;
+use crate::mmtk;
+use crate::upcalls;
+use crate::Ruby;
+use mmtk::memory_manager;
+use mmtk::scheduler::*;
+use mmtk::util::heap::GCTriggerPolicy;
+use mmtk::util::VMMutatorThread;
+use mmtk::util::VMThread;
+use mmtk::util::VMWorkerThread;
+use mmtk::vm::Collection;
+use mmtk::vm::GCThreadContext;
+use std::sync::atomic::AtomicBool;
+use std::sync::atomic::Ordering;
+use std::thread;
+
+static CURRENT_GC_MAY_MOVE: AtomicBool = AtomicBool::new(false);
+
+pub struct VMCollection {}
+
+impl Collection<Ruby> for VMCollection {
+ fn is_collection_enabled() -> bool {
+ crate::CONFIGURATION.gc_enabled.load(Ordering::Relaxed)
+ }
+
+ fn stop_all_mutators<F>(tls: VMWorkerThread, mut mutator_visitor: F)
+ where
+ F: FnMut(&'static mut mmtk::Mutator<Ruby>),
+ {
+ (upcalls().stop_the_world)();
+
+ if crate::mmtk().get_plan().current_gc_may_move_object() {
+ CURRENT_GC_MAY_MOVE.store(true, Ordering::Relaxed);
+ (upcalls().before_updating_jit_code)();
+ } else {
+ CURRENT_GC_MAY_MOVE.store(false, Ordering::Relaxed);
+ }
+
+ crate::binding().pinning_registry.pin_children(tls);
+
+ (upcalls().get_mutators)(
+ Self::notify_mutator_ready::<F>,
+ &mut mutator_visitor as *mut F as *mut _,
+ );
+ }
+
+ fn resume_mutators(_tls: VMWorkerThread) {
+ let current_gc_may_move = CURRENT_GC_MAY_MOVE.load(Ordering::Relaxed);
+
+ if current_gc_may_move {
+ (upcalls().after_updating_jit_code)();
+ }
+
+ (upcalls().resume_mutators)(current_gc_may_move);
+ }
+
+ fn block_for_gc(tls: VMMutatorThread) {
+ (upcalls().block_for_gc)(tls);
+ }
+
+ fn spawn_gc_thread(_tls: VMThread, ctx: GCThreadContext<Ruby>) {
+ let join_handle = match ctx {
+ GCThreadContext::Worker(mut worker) => thread::Builder::new()
+ .name("MMTk Worker Thread".to_string())
+ .spawn(move || {
+ let ordinal = worker.ordinal;
+ debug!("Hello! This is MMTk Worker Thread running! ordinal: {ordinal}");
+ crate::register_gc_thread(thread::current().id());
+ let ptr_worker = &mut *worker as *mut GCWorker<Ruby>;
+ let gc_thread_tls =
+ Box::into_raw(Box::new(GCThreadTLS::for_worker(ptr_worker)));
+ (upcalls().init_gc_worker_thread)(gc_thread_tls);
+ memory_manager::start_worker(
+ mmtk(),
+ GCThreadTLS::to_vwt(gc_thread_tls),
+ worker,
+ );
+ debug!("An MMTk Worker Thread is quitting. Good bye! ordinal: {ordinal}");
+ crate::unregister_gc_thread(thread::current().id());
+ })
+ .unwrap(),
+ };
+
+ {
+ let mut handles = crate::binding().gc_thread_join_handles.lock().unwrap();
+ handles.push(join_handle);
+ }
+ }
+
+ fn vm_live_bytes() -> usize {
+ (upcalls().vm_live_bytes)()
+ }
+
+ fn create_gc_trigger() -> Box<dyn GCTriggerPolicy<Ruby>> {
+ // `GCTriggerSelector::Delegated` is currently used by two different
+ // heap modes: `ruby` (the Ruby-like free-slot ratio trigger) and `cpu`
+ // (the CPU-overhead trigger from Tavakolisomeh et al., MPLR '23).
+ // Which one is active is determined by which `OnceCell` config the
+ // `MMTK_HEAP_MODE` parser populated.
+ if CPU_HEAP_TRIGGER_CONFIG.get().is_some() {
+ Box::new(CpuHeapTrigger::default())
+ } else {
+ Box::new(RubyHeapTrigger::default())
+ }
+ }
+}
+
+impl VMCollection {
+ extern "C" fn notify_mutator_ready<F>(mutator_ptr: *mut RubyMutator, data: *mut libc::c_void)
+ where
+ F: FnMut(&'static mut mmtk::Mutator<Ruby>),
+ {
+ let mutator = unsafe { &mut *mutator_ptr };
+ let mutator_visitor = unsafe { &mut *(data as *mut F) };
+ mutator_visitor(mutator);
+ }
+}
diff --git a/gc/mmtk/src/heap/cpu_heap_trigger.rs b/gc/mmtk/src/heap/cpu_heap_trigger.rs
new file mode 100644
index 0000000000..ef5a79fe9a
--- /dev/null
+++ b/gc/mmtk/src/heap/cpu_heap_trigger.rs
@@ -0,0 +1,370 @@
+//! A GC trigger that adjusts the heap size based on the CPU overhead of GC.
+//!
+//! This is an implementation of the heap sizing policy described in
+//! Tavakolisomeh, Shimchenko, Österlund, Bruno, Ferreira, Wrigstad,
+//! "Heap Size Adjustment with CPU Control", MPLR '23.
+//! <https://doi.org/10.1145/3617651.3622988>
+//!
+//! The idea: rather than letting heap size control GC frequency, let a
+//! user-supplied *target GC CPU overhead* control the heap size. After each GC
+//! cycle, we measure the GC CPU overhead (fraction of process CPU time spent
+//! in GC) and compare it to the target. If GC is over budget we grow the heap
+//! (reducing GC frequency); if it is under budget we shrink the heap (trading
+//! memory for more frequent collections).
+//!
+//! ## Algorithm
+//!
+//! After each GC cycle we compute, using an average of the last `n` cycles:
+//!
+//! ```text
+//! GC_CPU = T_GC / T_APP (Eq. 1)
+//! overhead_error = GC_CPU - target (Eq. 2)
+//! sigmoid_error = 1 / (1 + e^(-overhead_error)) (Eq. 3)
+//! adjustment_factor = sigmoid_error + 0.5 (in (0.5, 1.5)) (Eq. 4)
+//! new_size = current_size * adjustment_factor (Eq. 5)
+//! ```
+//!
+//! where:
+//! - `T_GC` is the wall-clock duration of each GC cycle.
+//! - `T_APP` is process CPU time elapsed between consecutive GC cycles (sum of
+//! CPU time over all threads — mutators, GC workers, compilers, etc.), read
+//! via `clock_gettime(CLOCK_PROCESS_CPUTIME_ID)`.
+//!
+//! The final heap size is then clamped to the range
+//! `[max(1.1 * used, min_heap_pages), max_heap_pages]`, providing 10% headroom
+//! above current live memory to avoid triggering GC on an effectively-empty
+//! heap.
+//!
+//! ## Differences from the paper
+//!
+//! The paper targets ZGC, a concurrent generational collector. MMTk's Ruby
+//! binding currently ships stop-the-world collectors (Immix, MarkSweep). The
+//! paper's formula still applies: with a STW collector the process CPU time
+//! during GC closely tracks the wall-clock GC time, and mutator CPU time
+//! during the mutator phase is correctly attributed. For generational plans
+//! we skip nursery-only GCs, consistent with MemBalancer.
+
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
+use std::sync::Mutex;
+
+use mmtk::util::heap::GCTriggerPolicy;
+use mmtk::util::heap::SpaceStats;
+use mmtk::Plan;
+use mmtk::MMTK;
+use once_cell::sync::OnceCell;
+
+use crate::Ruby;
+
+pub static CPU_HEAP_TRIGGER_CONFIG: OnceCell<CpuHeapTriggerConfig> = OnceCell::new();
+
+/// Configuration for the [`CpuHeapTrigger`].
+pub struct CpuHeapTriggerConfig {
+ /// Lower bound on heap size (in pages). The trigger will never shrink below
+ /// this value.
+ pub min_heap_pages: usize,
+ /// Upper bound on heap size (in pages). The trigger will never grow above
+ /// this value.
+ pub max_heap_pages: usize,
+ /// Initial heap size (in pages).
+ pub initial_heap_pages: usize,
+ /// Target GC CPU overhead as a fraction of total process CPU time. For
+ /// example, `0.15` means the policy will try to keep GC CPU usage near 15%.
+ /// Valid range: `(0.0, 1.0)`.
+ pub target_gc_cpu: f64,
+ /// Number of recent GC cycles averaged together when computing the CPU
+ /// overhead signal. Smoothes out short-term fluctuations. The paper uses 3.
+ pub window_size: usize,
+}
+
+/// A single GC cycle's timing measurements.
+#[derive(Clone, Copy, Debug, Default)]
+struct GcSample {
+ /// Wall-clock seconds spent inside this GC cycle.
+ gc_seconds: f64,
+ /// Seconds of process CPU time elapsed since the previous GC cycle ended.
+ /// This covers both mutator time and (on multi-threaded mutators) any
+ /// mutator CPU time consumed in parallel with the previous GC.
+ app_cpu_seconds: f64,
+}
+
+struct CpuHeapTriggerState {
+ /// Ring buffer of the last `window_size` samples. Oldest-first.
+ samples: Vec<GcSample>,
+ /// Wall-clock time when the current GC cycle started. `None` when no GC is
+ /// in progress.
+ gc_start_wall: Option<std::time::Instant>,
+ /// Process CPU time (seconds) recorded at the end of the previous GC
+ /// cycle. `None` until the first cycle completes.
+ last_gc_end_cpu: Option<f64>,
+}
+
+impl CpuHeapTriggerState {
+ fn new() -> Self {
+ Self {
+ samples: Vec::new(),
+ gc_start_wall: None,
+ last_gc_end_cpu: None,
+ }
+ }
+
+ /// Pushes a new sample, dropping the oldest when the window is full.
+ fn push_sample(&mut self, sample: GcSample, window_size: usize) {
+ if self.samples.len() >= window_size {
+ self.samples.remove(0);
+ }
+ self.samples.push(sample);
+ }
+
+ /// Returns the arithmetic mean GC CPU overhead across the window, or
+ /// `None` if we don't yet have a full sample (which happens on the first
+ /// GC cycle — we have no baseline for `app_cpu_seconds`).
+ fn mean_gc_cpu(&self) -> Option<f64> {
+ if self.samples.is_empty() {
+ return None;
+ }
+ let total_gc: f64 = self.samples.iter().map(|s| s.gc_seconds).sum();
+ let total_app: f64 = self.samples.iter().map(|s| s.app_cpu_seconds).sum();
+ if total_app <= 0.0 {
+ return None;
+ }
+ Some(total_gc / total_app)
+ }
+}
+
+pub struct CpuHeapTrigger {
+ /// Target heap size in pages. Updated at the end of each GC cycle.
+ target_heap_pages: AtomicUsize,
+ /// Mutable timing state. Wrapped in a `Mutex` because `on_gc_start` and
+ /// `on_gc_end` are the only mutation sites and they are not on an
+ /// allocation hot path; avoiding the complexity of lock-free state is
+ /// worth the trivial contention.
+ state: Mutex<CpuHeapTriggerState>,
+}
+
+impl Default for CpuHeapTrigger {
+ fn default() -> Self {
+ let cfg = Self::get_config();
+ Self {
+ target_heap_pages: AtomicUsize::new(cfg.initial_heap_pages),
+ state: Mutex::new(CpuHeapTriggerState::new()),
+ }
+ }
+}
+
+impl GCTriggerPolicy<Ruby> for CpuHeapTrigger {
+ fn is_gc_required(
+ &self,
+ space_full: bool,
+ space: Option<SpaceStats<Ruby>>,
+ plan: &dyn Plan<VM = Ruby>,
+ ) -> bool {
+ // Let the plan decide, matching the other triggers.
+ plan.collection_required(space_full, space)
+ }
+
+ fn on_gc_start(&self, _mmtk: &'static MMTK<Ruby>) {
+ let mut state = self.state.lock().unwrap();
+ state.gc_start_wall = Some(std::time::Instant::now());
+ }
+
+ fn on_gc_end(&self, mmtk: &'static MMTK<Ruby>) {
+ // Skip nursery-only GCs for generational plans. The heap resizing
+ // decision is driven by the (much more expensive) full collections
+ // where the signal-to-noise ratio is high enough to be useful.
+ if let Some(gen_plan) = mmtk.get_plan().generational() {
+ if gen_plan.is_current_gc_nursery() {
+ return;
+ }
+ }
+
+ let cfg = Self::get_config();
+ let gc_end_cpu = process_cpu_time_seconds();
+
+ let mut state = self.state.lock().unwrap();
+
+ // Duration of this GC cycle (wall clock).
+ let gc_seconds = state
+ .gc_start_wall
+ .take()
+ .map(|start| start.elapsed().as_secs_f64())
+ .unwrap_or(0.0);
+
+ // Process CPU time elapsed since the previous GC cycle ended. We
+ // require at least one previous end timestamp to produce a valid
+ // sample — without it we cannot compute `T_APP`.
+ if let (Some(last_end), Some(now)) = (state.last_gc_end_cpu, gc_end_cpu) {
+ let app_cpu_seconds = (now - last_end).max(0.0);
+ // Only record non-degenerate samples to avoid poisoning the window
+ // with zero-time entries from back-to-back GCs.
+ if app_cpu_seconds > 0.0 {
+ state.push_sample(
+ GcSample {
+ gc_seconds,
+ app_cpu_seconds,
+ },
+ cfg.window_size,
+ );
+ }
+ }
+ state.last_gc_end_cpu = gc_end_cpu;
+
+ // Compute the new heap size only when we have samples to average over.
+ if let Some(gc_cpu) = state.mean_gc_cpu() {
+ // Drop the lock before doing the (relatively cheap) math and
+ // atomic update; nothing below needs the state.
+ drop(state);
+
+ let overhead_error = gc_cpu - cfg.target_gc_cpu; // Eq. (2)
+ let sigmoid_error = sigmoid(overhead_error); // Eq. (3)
+ let adjustment_factor = sigmoid_error + 0.5; // Eq. (4), range (0.5, 1.5)
+
+ let current = self.target_heap_pages.load(Ordering::Relaxed);
+ let suggested = ((current as f64) * adjustment_factor) as usize; // Eq. (5)
+
+ // Clamp:
+ // - upper bound: configured max
+ // - lower bound: max(1.1 * used, min) — 10% headroom above current
+ // live memory, so we never request a heap so small that GC is
+ // triggered immediately on return from this one.
+ let used = mmtk.get_plan().get_used_pages();
+ let floor = ((used as f64) * 1.1).ceil() as usize;
+ let lower = floor.max(cfg.min_heap_pages).min(cfg.max_heap_pages);
+ let upper = cfg.max_heap_pages;
+ let new_target = suggested.clamp(lower, upper);
+
+ self.target_heap_pages.store(new_target, Ordering::Relaxed);
+
+ info!(
+ "CpuHeapTrigger: gc_cpu={:.4} target={:.4} factor={:.4} \
+ pages {} -> {} (used={}, clamp=[{}, {}])",
+ gc_cpu,
+ cfg.target_gc_cpu,
+ adjustment_factor,
+ current,
+ new_target,
+ used,
+ lower,
+ upper
+ );
+ }
+ }
+
+ fn is_heap_full(&self, plan: &dyn Plan<VM = Ruby>) -> bool {
+ plan.get_reserved_pages() > self.target_heap_pages.load(Ordering::Relaxed)
+ }
+
+ fn get_current_heap_size_in_pages(&self) -> usize {
+ self.target_heap_pages.load(Ordering::Relaxed)
+ }
+
+ fn get_max_heap_size_in_pages(&self) -> usize {
+ Self::get_config().max_heap_pages
+ }
+
+ fn can_heap_size_grow(&self) -> bool {
+ self.target_heap_pages.load(Ordering::Relaxed) < Self::get_config().max_heap_pages
+ }
+}
+
+impl CpuHeapTrigger {
+ fn get_config<'b>() -> &'b CpuHeapTriggerConfig {
+ CPU_HEAP_TRIGGER_CONFIG
+ .get()
+ .expect("Attempt to use CPU_HEAP_TRIGGER_CONFIG before it is initialized")
+ }
+}
+
+/// Standard logistic sigmoid. Returns 0.5 when x == 0, asymptotes to 0 and 1.
+fn sigmoid(x: f64) -> f64 {
+ 1.0 / (1.0 + (-x).exp())
+}
+
+/// Reads the process-wide CPU time as a floating-point number of seconds,
+/// summed across all threads of this process. Returns `None` if the clock
+/// query fails (which should be essentially impossible on supported
+/// platforms).
+fn process_cpu_time_seconds() -> Option<f64> {
+ let mut ts = libc::timespec {
+ tv_sec: 0,
+ tv_nsec: 0,
+ };
+ // SAFETY: `clock_gettime` writes exactly `sizeof(timespec)` bytes to the
+ // pointer we pass, which is a valid local stack allocation.
+ let rc = unsafe { libc::clock_gettime(libc::CLOCK_PROCESS_CPUTIME_ID, &mut ts) };
+ if rc != 0 {
+ return None;
+ }
+ Some((ts.tv_sec as f64) + (ts.tv_nsec as f64) / 1_000_000_000.0)
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ #[test]
+ fn sigmoid_is_well_behaved() {
+ assert!((sigmoid(0.0) - 0.5).abs() < 1e-12);
+ assert!(sigmoid(-100.0) < 1e-9);
+ assert!(sigmoid(100.0) > 1.0 - 1e-9);
+ // Monotonic.
+ assert!(sigmoid(-1.0) < sigmoid(0.0));
+ assert!(sigmoid(0.0) < sigmoid(1.0));
+ }
+
+ #[test]
+ fn adjustment_factor_is_within_paper_bounds() {
+ // Eq. (4): adjustment_factor = sigmoid(e) + 0.5 must lie in (0.5, 1.5).
+ for e in [-10.0_f64, -1.0, 0.0, 1.0, 10.0] {
+ let f = sigmoid(e) + 0.5;
+ assert!(f > 0.5 && f < 1.5, "factor {f} out of range for e={e}");
+ }
+ }
+
+ #[test]
+ fn mean_gc_cpu_is_total_weighted() {
+ let mut state = CpuHeapTriggerState::new();
+ state.push_sample(
+ GcSample {
+ gc_seconds: 1.0,
+ app_cpu_seconds: 10.0,
+ },
+ 3,
+ );
+ state.push_sample(
+ GcSample {
+ gc_seconds: 3.0,
+ app_cpu_seconds: 10.0,
+ },
+ 3,
+ );
+ // (1 + 3) / (10 + 10) = 0.2
+ assert!((state.mean_gc_cpu().unwrap() - 0.2).abs() < 1e-12);
+ }
+
+ #[test]
+ fn window_drops_oldest() {
+ let mut state = CpuHeapTriggerState::new();
+ for i in 0..5 {
+ state.push_sample(
+ GcSample {
+ gc_seconds: i as f64,
+ app_cpu_seconds: 1.0,
+ },
+ 3,
+ );
+ }
+ assert_eq!(state.samples.len(), 3);
+ // After pushing 0,1,2,3,4 with window 3, we should have [2,3,4].
+ assert_eq!(state.samples[0].gc_seconds, 2.0);
+ assert_eq!(state.samples[2].gc_seconds, 4.0);
+ }
+
+ #[test]
+ fn no_sample_without_prior_gc() {
+ // First GC cycle cannot produce a sample (no previous end time). The
+ // push happens only when last_gc_end_cpu is Some.
+ let state = CpuHeapTriggerState::new();
+ assert!(state.mean_gc_cpu().is_none());
+ }
+}
diff --git a/gc/mmtk/src/heap/mod.rs b/gc/mmtk/src/heap/mod.rs
new file mode 100644
index 0000000000..05a35efb23
--- /dev/null
+++ b/gc/mmtk/src/heap/mod.rs
@@ -0,0 +1,9 @@
+mod cpu_heap_trigger;
+mod ruby_heap_trigger;
+
+pub use cpu_heap_trigger::CpuHeapTrigger;
+pub use cpu_heap_trigger::CpuHeapTriggerConfig;
+pub use cpu_heap_trigger::CPU_HEAP_TRIGGER_CONFIG;
+pub use ruby_heap_trigger::RubyHeapTrigger;
+pub use ruby_heap_trigger::RubyHeapTriggerConfig;
+pub use ruby_heap_trigger::RUBY_HEAP_TRIGGER_CONFIG;
diff --git a/gc/mmtk/src/heap/ruby_heap_trigger.rs b/gc/mmtk/src/heap/ruby_heap_trigger.rs
new file mode 100644
index 0000000000..fe1130043d
--- /dev/null
+++ b/gc/mmtk/src/heap/ruby_heap_trigger.rs
@@ -0,0 +1,105 @@
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
+
+use mmtk::util::heap::GCTriggerPolicy;
+use mmtk::util::heap::SpaceStats;
+use mmtk::Plan;
+use mmtk::MMTK;
+use once_cell::sync::OnceCell;
+
+use crate::Ruby;
+
+pub static RUBY_HEAP_TRIGGER_CONFIG: OnceCell<RubyHeapTriggerConfig> = OnceCell::new();
+
+pub struct RubyHeapTriggerConfig {
+ /// Min heap size
+ pub min_heap_pages: usize,
+ /// Max heap size
+ pub max_heap_pages: usize,
+ /// Minimum ratio of empty space after a GC before the heap will grow
+ pub heap_pages_min_ratio: f64,
+ /// Ratio the heap will grow by
+ pub heap_pages_goal_ratio: f64,
+ /// Maximum ratio of empty space after a GC before the heap will shrink
+ pub heap_pages_max_ratio: f64,
+}
+
+pub struct RubyHeapTrigger {
+ /// Target number of heap pages
+ target_heap_pages: AtomicUsize,
+}
+
+impl GCTriggerPolicy<Ruby> for RubyHeapTrigger {
+ fn is_gc_required(
+ &self,
+ space_full: bool,
+ space: Option<SpaceStats<Ruby>>,
+ plan: &dyn Plan<VM = Ruby>,
+ ) -> bool {
+ // Let the plan decide
+ plan.collection_required(space_full, space)
+ }
+
+ fn on_gc_end(&self, mmtk: &'static MMTK<Ruby>) {
+ if let Some(plan) = mmtk.get_plan().generational() {
+ if plan.is_current_gc_nursery() {
+ // Nursery GC
+ } else {
+ // Full GC
+ }
+
+ panic!("TODO: support for generational GC not implemented")
+ } else {
+ let used_pages = mmtk.get_plan().get_used_pages();
+
+ let target_min =
+ (used_pages as f64 * (1.0 + Self::get_config().heap_pages_min_ratio)) as usize;
+ let target_max =
+ (used_pages as f64 * (1.0 + Self::get_config().heap_pages_max_ratio)) as usize;
+ let new_target =
+ (((used_pages as f64) * (1.0 + Self::get_config().heap_pages_goal_ratio)) as usize)
+ .clamp(
+ Self::get_config().min_heap_pages,
+ Self::get_config().max_heap_pages,
+ );
+
+ if used_pages < target_min || used_pages > target_max {
+ self.target_heap_pages.store(new_target, Ordering::Relaxed);
+ }
+ }
+ }
+
+ fn is_heap_full(&self, plan: &dyn Plan<VM = Ruby>) -> bool {
+ plan.get_reserved_pages() > self.target_heap_pages.load(Ordering::Relaxed)
+ }
+
+ fn get_current_heap_size_in_pages(&self) -> usize {
+ self.target_heap_pages.load(Ordering::Relaxed)
+ }
+
+ fn get_max_heap_size_in_pages(&self) -> usize {
+ Self::get_config().max_heap_pages
+ }
+
+ fn can_heap_size_grow(&self) -> bool {
+ self.target_heap_pages.load(Ordering::Relaxed) < Self::get_config().max_heap_pages
+ }
+}
+
+impl Default for RubyHeapTrigger {
+ fn default() -> Self {
+ let min_heap_pages = Self::get_config().min_heap_pages;
+
+ Self {
+ target_heap_pages: AtomicUsize::new(min_heap_pages),
+ }
+ }
+}
+
+impl RubyHeapTrigger {
+ fn get_config<'b>() -> &'b RubyHeapTriggerConfig {
+ RUBY_HEAP_TRIGGER_CONFIG
+ .get()
+ .expect("Attempt to use RUBY_HEAP_TRIGGER_CONFIG before it is initialized")
+ }
+}
diff --git a/gc/mmtk/src/lib.rs b/gc/mmtk/src/lib.rs
new file mode 100644
index 0000000000..52dc782051
--- /dev/null
+++ b/gc/mmtk/src/lib.rs
@@ -0,0 +1,161 @@
+// Warn about unsafe operations in functions that are already marked as unsafe.
+// This will become default in Rust 2024 edition.
+#![warn(unsafe_op_in_unsafe_fn)]
+
+extern crate libc;
+extern crate mmtk;
+#[macro_use]
+extern crate log;
+extern crate probe;
+
+use std::collections::HashSet;
+use std::panic::PanicHookInfo;
+use std::sync::Mutex;
+use std::thread::ThreadId;
+
+use abi::RubyUpcalls;
+use binding::RubyBinding;
+use binding::RubyBindingFast;
+use binding::RubyConfiguration;
+use mmtk::vm::slot::SimpleSlot;
+use mmtk::vm::slot::UnimplementedMemorySlice;
+use mmtk::vm::VMBinding;
+use mmtk::MMTK;
+use once_cell::sync::OnceCell;
+
+pub mod abi;
+pub mod active_plan;
+pub mod api;
+pub mod binding;
+pub mod collection;
+pub mod heap;
+pub mod object_model;
+pub mod pinning_registry;
+pub mod reference_glue;
+pub mod scanning;
+pub mod utils;
+pub mod weak_proc;
+
+#[derive(Default)]
+pub struct Ruby;
+
+/// Ruby slot type, i.e. a slot that holds a VALUE.
+/// Currently we use SimpleSlot.
+/// It doesn't matter, becaues we have not started using slot-enqueuing, yet.
+pub type RubySlot = SimpleSlot;
+
+/// Ruby memory slice, i.e. an array of VALUEs.
+/// It is used by array-copy barriers which is supposed to perform bettern than copying array
+/// elements one by one. At this moment, we just leave it unimplemented.
+pub type RubyMemorySlice = UnimplementedMemorySlice<RubySlot>;
+
+impl VMBinding for Ruby {
+ type VMObjectModel = object_model::VMObjectModel;
+ type VMScanning = scanning::VMScanning;
+ type VMCollection = collection::VMCollection;
+ type VMActivePlan = active_plan::VMActivePlan;
+ type VMReferenceGlue = reference_glue::VMReferenceGlue;
+
+ type VMSlot = RubySlot;
+ type VMMemorySlice = RubyMemorySlice;
+}
+
+/// The callback for mutator thread panic handler (which calls rb_bug to output
+/// debugging information such as the Ruby backtrace and memory maps).
+/// This is set before BINDING is set because mmtk_init could panic.
+pub static MUTATOR_THREAD_PANIC_HANDLER: OnceCell<extern "C" fn()> = OnceCell::new();
+
+/// The singleton object for the Ruby binding itself.
+pub static BINDING: OnceCell<RubyBinding> = OnceCell::new();
+
+/// Some data needs to be accessed fast.
+/// We sacrifice safety for speed using unsynchronized global variables.
+pub static mut BINDING_FAST: RubyBindingFast = RubyBindingFast::new();
+
+/// Some data needs to be accessed fast.
+pub static CONFIGURATION: RubyConfiguration = RubyConfiguration::new();
+
+pub fn binding<'b>() -> &'b RubyBinding {
+ BINDING
+ .get()
+ .expect("Attempt to use the binding before it is initialization")
+}
+
+pub fn mmtk() -> &'static MMTK<Ruby> {
+ binding().mmtk
+}
+
+pub fn upcalls() -> &'static RubyUpcalls {
+ binding().upcalls()
+}
+
+pub static GC_THREADS: OnceCell<Mutex<HashSet<ThreadId>>> = OnceCell::new();
+
+pub(crate) fn register_gc_thread(thread_id: ThreadId) {
+ let mut gc_threads = GC_THREADS.get().unwrap().lock().unwrap();
+ gc_threads.insert(thread_id);
+}
+
+pub(crate) fn unregister_gc_thread(thread_id: ThreadId) {
+ let mut gc_threads = GC_THREADS.get().unwrap().lock().unwrap();
+ gc_threads.remove(&thread_id);
+}
+
+pub(crate) fn is_gc_thread(thread_id: ThreadId) -> bool {
+ let gc_threads = GC_THREADS.get().unwrap().lock().unwrap();
+ gc_threads.contains(&thread_id)
+}
+
+fn handle_gc_thread_panic(panic_info: &PanicHookInfo) {
+ eprintln!("ERROR: An MMTk GC thread panicked. This is a bug.");
+ eprintln!("{panic_info}");
+
+ let bt = std::backtrace::Backtrace::capture();
+ match bt.status() {
+ std::backtrace::BacktraceStatus::Unsupported => {
+ eprintln!("Backtrace is unsupported.")
+ }
+ std::backtrace::BacktraceStatus::Disabled => {
+ eprintln!("Backtrace is disabled.");
+ eprintln!("run with `RUST_BACKTRACE=1` environment variable to display a backtrace");
+ }
+ std::backtrace::BacktraceStatus::Captured => {
+ eprintln!("{bt}");
+ }
+ s => {
+ eprintln!("Unknown backtrace status: {s:?}");
+ }
+ }
+}
+
+pub(crate) fn set_panic_hook() {
+ if GC_THREADS.set(Default::default()).is_err() {
+ return;
+ }
+
+ let old_hook = std::panic::take_hook();
+
+ std::panic::set_hook(Box::new(move |panic_info| {
+ if is_gc_thread(std::thread::current().id()) {
+ handle_gc_thread_panic(panic_info);
+
+ (crate::binding().upcalls().gc_thread_panic_handler)();
+ } else {
+ old_hook(panic_info);
+ (crate::MUTATOR_THREAD_PANIC_HANDLER
+ .get()
+ .expect("MUTATOR_THREAD_PANIC_HANDLER is not set"))();
+ }
+ }));
+}
+
+/// This kind of assertion is enabled if either building in debug mode or the
+/// "extra_assert" feature is enabled.
+#[macro_export]
+macro_rules! extra_assert {
+ ($($arg:tt)*) => {
+ if std::cfg!(any(debug_assertions, feature = "extra_assert")) {
+ std::assert!($($arg)*);
+ }
+ };
+}
diff --git a/gc/mmtk/src/object_model.rs b/gc/mmtk/src/object_model.rs
new file mode 100644
index 0000000000..d673ca11a0
--- /dev/null
+++ b/gc/mmtk/src/object_model.rs
@@ -0,0 +1,124 @@
+use std::ptr::copy_nonoverlapping;
+
+use crate::abi;
+use crate::abi::RubyObjectAccess;
+use crate::abi::MIN_OBJ_ALIGN;
+use crate::abi::OBJREF_OFFSET;
+use crate::Ruby;
+use mmtk::util::constants::BITS_IN_BYTE;
+use mmtk::util::copy::CopySemantics;
+use mmtk::util::copy::GCWorkerCopyContext;
+use mmtk::util::Address;
+use mmtk::util::ObjectReference;
+use mmtk::vm::*;
+
+pub struct VMObjectModel {}
+
+impl VMObjectModel {
+ const OBJREF_OFFSET: usize = abi::OBJREF_OFFSET;
+}
+
+impl ObjectModel<Ruby> for VMObjectModel {
+ const GLOBAL_LOG_BIT_SPEC: VMGlobalLogBitSpec = VMGlobalLogBitSpec::side_first();
+
+ // We overwrite the prepended word which were used to hold object sizes.
+ const LOCAL_FORWARDING_POINTER_SPEC: VMLocalForwardingPointerSpec =
+ VMLocalForwardingPointerSpec::in_header(-((OBJREF_OFFSET * BITS_IN_BYTE) as isize));
+
+ const LOCAL_FORWARDING_BITS_SPEC: VMLocalForwardingBitsSpec =
+ VMLocalForwardingBitsSpec::side_first();
+
+ const LOCAL_MARK_BIT_SPEC: VMLocalMarkBitSpec =
+ VMLocalMarkBitSpec::side_after(Self::LOCAL_FORWARDING_BITS_SPEC.as_spec());
+
+ const LOCAL_PINNING_BIT_SPEC: VMLocalPinningBitSpec =
+ VMLocalPinningBitSpec::side_after(Self::LOCAL_MARK_BIT_SPEC.as_spec());
+
+ const LOCAL_LOS_MARK_NURSERY_SPEC: VMLocalLOSMarkNurserySpec =
+ VMLocalLOSMarkNurserySpec::side_after(Self::LOCAL_PINNING_BIT_SPEC.as_spec());
+
+ const UNIFIED_OBJECT_REFERENCE_ADDRESS: bool = false;
+ const OBJECT_REF_OFFSET_LOWER_BOUND: isize = Self::OBJREF_OFFSET as isize;
+
+ const NEED_VO_BITS_DURING_TRACING: bool = true;
+
+ fn copy(
+ from: ObjectReference,
+ semantics: CopySemantics,
+ copy_context: &mut GCWorkerCopyContext<Ruby>,
+ ) -> ObjectReference {
+ let from_acc = RubyObjectAccess::from_objref(from);
+ let from_start = from_acc.obj_start();
+ let object_size = from_acc.object_size();
+ let to_start = copy_context.alloc_copy(from, object_size, MIN_OBJ_ALIGN, 0, semantics);
+ debug_assert!(!to_start.is_zero());
+ let to_payload = to_start.add(OBJREF_OFFSET);
+ unsafe {
+ copy_nonoverlapping::<u8>(from_start.to_ptr(), to_start.to_mut_ptr(), object_size);
+ }
+ let to_obj = unsafe { ObjectReference::from_raw_address_unchecked(to_payload) };
+ copy_context.post_copy(to_obj, object_size, semantics);
+ trace!("Copied object from {} to {}", from, to_obj);
+
+ (crate::binding().upcalls().move_obj_during_marking)(from, to_obj);
+
+ #[cfg(feature = "clear_old_copy")]
+ {
+ trace!(
+ "Clearing old copy {} ({}-{})",
+ from,
+ from_start,
+ from_start + object_size
+ );
+ // For debug purpose, we clear the old copy so that if the Ruby VM reads from the old
+ // copy again, it will likely result in an error.
+ unsafe { std::ptr::write_bytes::<u8>(from_start.to_mut_ptr(), 0, object_size) }
+ }
+
+ to_obj
+ }
+
+ fn copy_to(_from: ObjectReference, _to: ObjectReference, _region: Address) -> Address {
+ unimplemented!(
+ "This function cannot be called because we do not support MarkCompact for Ruby."
+ )
+ }
+
+ fn get_reference_when_copied_to(_from: ObjectReference, _to: Address) -> ObjectReference {
+ unimplemented!(
+ "This function cannot be called because we do not support MarkCompact for Ruby."
+ )
+ }
+
+ fn get_current_size(object: ObjectReference) -> usize {
+ RubyObjectAccess::from_objref(object).object_size()
+ }
+
+ fn get_type_descriptor(_reference: ObjectReference) -> &'static [i8] {
+ todo!()
+ }
+
+ fn ref_to_object_start(object: ObjectReference) -> Address {
+ RubyObjectAccess::from_objref(object).obj_start()
+ }
+
+ fn ref_to_header(object: ObjectReference) -> Address {
+ RubyObjectAccess::from_objref(object).payload_addr()
+ }
+
+ fn get_size_when_copied(object: ObjectReference) -> usize {
+ Self::get_current_size(object)
+ }
+
+ fn get_align_when_copied(_object: ObjectReference) -> usize {
+ todo!()
+ }
+
+ fn get_align_offset_when_copied(_object: ObjectReference) -> usize {
+ todo!()
+ }
+
+ fn dump_object(_object: ObjectReference) {
+ todo!()
+ }
+}
diff --git a/gc/mmtk/src/pinning_registry.rs b/gc/mmtk/src/pinning_registry.rs
new file mode 100644
index 0000000000..b498b508f1
--- /dev/null
+++ b/gc/mmtk/src/pinning_registry.rs
@@ -0,0 +1,187 @@
+use std::sync::Mutex;
+
+use mmtk::memory_manager;
+use mmtk::scheduler::GCWork;
+use mmtk::scheduler::GCWorker;
+use mmtk::scheduler::WorkBucketStage;
+use mmtk::util::ObjectReference;
+use mmtk::util::VMWorkerThread;
+use mmtk::MMTK;
+
+use crate::abi::GCThreadTLS;
+use crate::upcalls;
+use crate::Ruby;
+
+pub struct PinningRegistry {
+ pinning_objs: Mutex<Vec<ObjectReference>>,
+ pinned_objs: Mutex<Vec<ObjectReference>>,
+}
+
+impl PinningRegistry {
+ pub fn new() -> Self {
+ Self {
+ pinning_objs: Default::default(),
+ pinned_objs: Default::default(),
+ }
+ }
+
+ pub fn register(&self, object: ObjectReference) {
+ let mut pinning_objs = self.pinning_objs.lock().unwrap();
+ pinning_objs.push(object);
+ }
+
+ pub fn pin_children(&self, tls: VMWorkerThread) {
+ if !crate::mmtk().get_plan().current_gc_may_move_object() {
+ log::debug!("The current GC is non-moving, skipping pinning children.");
+ return;
+ }
+
+ let gc_tls = unsafe { GCThreadTLS::from_vwt_check(tls) };
+ let worker = gc_tls.worker();
+
+ let pinning_objs = self
+ .pinning_objs
+ .try_lock()
+ .expect("PinningRegistry should not have races during GC.");
+
+ let packet_size = 512;
+ let work_packets = pinning_objs
+ .chunks(packet_size)
+ .map(|chunk| {
+ Box::new(PinPinningChildren {
+ pinning_objs: chunk.to_vec(),
+ }) as _
+ })
+ .collect();
+
+ worker.scheduler().work_buckets[WorkBucketStage::Prepare].bulk_add(work_packets);
+ }
+
+ pub fn cleanup(&self, worker: &mut GCWorker<Ruby>) {
+ worker.scheduler().work_buckets[WorkBucketStage::VMRefClosure].add(RemoveDeadPinnings);
+ if crate::mmtk().get_plan().current_gc_may_move_object() {
+ let packet = {
+ let mut pinned_objs = self
+ .pinned_objs
+ .try_lock()
+ .expect("Unexpected contention on pinned_objs");
+ UnpinPinnedObjects {
+ objs: std::mem::take(&mut pinned_objs),
+ }
+ };
+
+ worker.scheduler().work_buckets[WorkBucketStage::VMRefClosure].add(packet);
+ } else {
+ debug!("The current GC is non-moving, skipping unpinning objects.");
+ debug_assert_eq!(
+ {
+ let pinned_objs = self
+ .pinned_objs
+ .try_lock()
+ .expect("Unexpected contention on pinned_objs");
+ pinned_objs.len()
+ },
+ 0
+ );
+ }
+ }
+}
+
+impl Default for PinningRegistry {
+ fn default() -> Self {
+ Self::new()
+ }
+}
+
+struct PinPinningChildren {
+ pinning_objs: Vec<ObjectReference>,
+}
+
+impl GCWork<Ruby> for PinPinningChildren {
+ fn do_work(&mut self, worker: &mut GCWorker<Ruby>, _mmtk: &'static MMTK<Ruby>) {
+ let gc_tls = unsafe { GCThreadTLS::from_vwt_check(worker.tls) };
+ let mut pinned_objs = vec![];
+ let mut newly_pinned_objs = vec![];
+
+ let visit_object = |_worker, target_object: ObjectReference, pin| {
+ log::trace!(
+ " -> {} {}",
+ if pin { "(pin)" } else { " " },
+ target_object
+ );
+ if pin {
+ debug_assert!(
+ target_object.get_forwarded_object().is_none(),
+ "Trying to pin {target_object} but has been moved"
+ );
+
+ pinned_objs.push(target_object);
+ }
+ target_object
+ };
+
+ gc_tls
+ .object_closure
+ .set_temporarily_and_run_code(visit_object, || {
+ for obj in self.pinning_objs.iter().cloned() {
+ log::trace!(" Pinning: {}", obj);
+ (upcalls().call_gc_mark_children)(obj);
+ }
+ });
+
+ for target_object in pinned_objs {
+ if memory_manager::pin_object(target_object) {
+ newly_pinned_objs.push(target_object);
+ }
+ }
+
+ let mut pinned_objs = crate::binding()
+ .pinning_registry
+ .pinned_objs
+ .lock()
+ .unwrap();
+ pinned_objs.append(&mut newly_pinned_objs);
+ }
+}
+
+struct RemoveDeadPinnings;
+
+impl GCWork<Ruby> for RemoveDeadPinnings {
+ fn do_work(&mut self, _worker: &mut GCWorker<Ruby>, _mmtk: &'static MMTK<Ruby>) {
+ log::debug!("Removing dead Pinnings...");
+
+ let registry = &crate::binding().pinning_registry;
+ {
+ let mut pinning_objs = registry
+ .pinning_objs
+ .try_lock()
+ .expect("PinningRegistry should not have races during GC.");
+
+ pinning_objs.retain_mut(|obj| {
+ if obj.is_live() {
+ let new_obj = obj.get_forwarded_object().unwrap_or(*obj);
+ *obj = new_obj;
+ true
+ } else {
+ log::trace!(" Dead Pinning removed: {}", *obj);
+ false
+ }
+ });
+ }
+ }
+}
+
+struct UnpinPinnedObjects {
+ objs: Vec<ObjectReference>,
+}
+
+impl GCWork<Ruby> for UnpinPinnedObjects {
+ fn do_work(&mut self, _worker: &mut GCWorker<Ruby>, _mmtk: &'static MMTK<Ruby>) {
+ log::debug!("Unpinning pinned objects...");
+
+ for obj in self.objs.iter() {
+ let unpinned = memory_manager::unpin_object(*obj);
+ debug_assert!(unpinned);
+ }
+ }
+}
diff --git a/gc/mmtk/src/reference_glue.rs b/gc/mmtk/src/reference_glue.rs
new file mode 100644
index 0000000000..1272bd54c1
--- /dev/null
+++ b/gc/mmtk/src/reference_glue.rs
@@ -0,0 +1,26 @@
+use crate::Ruby;
+use mmtk::util::ObjectReference;
+use mmtk::util::VMWorkerThread;
+use mmtk::vm::ReferenceGlue;
+
+pub struct VMReferenceGlue {}
+
+impl ReferenceGlue<Ruby> for VMReferenceGlue {
+ type FinalizableType = ObjectReference;
+
+ fn get_referent(_object: ObjectReference) -> Option<ObjectReference> {
+ unimplemented!()
+ }
+
+ fn set_referent(_reff: ObjectReference, _referent: ObjectReference) {
+ unimplemented!()
+ }
+
+ fn enqueue_references(_references: &[ObjectReference], _tls: VMWorkerThread) {
+ unimplemented!()
+ }
+
+ fn clear_referent(_new_reference: ObjectReference) {
+ unimplemented!()
+ }
+}
diff --git a/gc/mmtk/src/scanning.rs b/gc/mmtk/src/scanning.rs
new file mode 100644
index 0000000000..355a2e7759
--- /dev/null
+++ b/gc/mmtk/src/scanning.rs
@@ -0,0 +1,291 @@
+use crate::abi::GCThreadTLS;
+
+use crate::upcalls;
+use crate::utils::ChunkedVecCollector;
+use crate::Ruby;
+use crate::RubySlot;
+use mmtk::memory_manager;
+use mmtk::scheduler::GCWork;
+use mmtk::scheduler::GCWorker;
+use mmtk::scheduler::WorkBucketStage;
+use mmtk::util::ObjectReference;
+use mmtk::util::VMWorkerThread;
+use mmtk::vm::ObjectTracer;
+use mmtk::vm::RootsWorkFactory;
+use mmtk::vm::Scanning;
+use mmtk::vm::SlotVisitor;
+use mmtk::Mutator;
+
+pub struct VMScanning {}
+
+impl Scanning<Ruby> for VMScanning {
+ const UNIQUE_OBJECT_ENQUEUING: bool = true;
+
+ fn support_slot_enqueuing(_tls: VMWorkerThread, _object: ObjectReference) -> bool {
+ false
+ }
+
+ fn scan_object<EV: SlotVisitor<RubySlot>>(
+ _tls: VMWorkerThread,
+ _object: ObjectReference,
+ _slot_visitor: &mut EV,
+ ) {
+ unreachable!("We have not enabled slot enqueuing for any types, yet.");
+ }
+
+ fn scan_object_and_trace_edges<OT: ObjectTracer>(
+ tls: VMWorkerThread,
+ object: ObjectReference,
+ object_tracer: &mut OT,
+ ) {
+ debug_assert!(
+ mmtk::memory_manager::is_mmtk_object(object.to_raw_address()).is_some(),
+ "Not an MMTk object: {object}",
+ );
+ let gc_tls = unsafe { GCThreadTLS::from_vwt_check(tls) };
+ let visit_object = |_worker, target_object: ObjectReference, pin| {
+ trace!(
+ "Tracing edge: {} -> {}{}",
+ object,
+ target_object,
+ if pin { " pin" } else { "" }
+ );
+ debug_assert!(
+ mmtk::memory_manager::is_mmtk_object(target_object.to_raw_address()).is_some(),
+ "Destination is not an MMTk object. Src: {object} dst: {target_object}"
+ );
+
+ debug_assert!(
+ // If we are in a moving GC, all objects should be pinned by PinningRegistry.
+ // If it is requested that target_object be pinned but it is not pinned, then
+ // it is a bug because it could be moved.
+ if crate::mmtk().get_plan().current_gc_may_move_object() && pin {
+ memory_manager::is_pinned(target_object)
+ } else {
+ true
+ },
+ "Object {object} is trying to pin {target_object}"
+ );
+
+ let forwarded_target = object_tracer.trace_object(target_object);
+ if forwarded_target != target_object {
+ trace!(" Forwarded target {target_object} -> {forwarded_target}");
+ }
+ forwarded_target
+ };
+ gc_tls
+ .object_closure
+ .set_temporarily_and_run_code(visit_object, || {
+ (upcalls().call_gc_mark_children)(object);
+
+ if crate::mmtk().get_plan().current_gc_may_move_object() {
+ (upcalls().update_object_references)(object);
+ }
+ });
+ }
+
+ fn notify_initial_thread_scan_complete(_partial_scan: bool, _tls: VMWorkerThread) {
+ // Do nothing
+ }
+
+ fn scan_roots_in_mutator_thread(
+ _tls: VMWorkerThread,
+ _mutator: &'static mut Mutator<Ruby>,
+ mut _factory: impl RootsWorkFactory<RubySlot>,
+ ) {
+ // Do nothing. All stacks (including Ruby stacks and machine stacks) are reachable from
+ // `rb_vm_t` -> ractor -> thread -> fiber -> stacks. It is part of `ScanGCRoots` which
+ // calls `rb_gc_mark_roots` -> `rb_vm_mark`.
+ }
+
+ fn scan_vm_specific_roots(tls: VMWorkerThread, factory: impl RootsWorkFactory<RubySlot>) {
+ let gc_tls = unsafe { GCThreadTLS::from_vwt_check(tls) };
+ let root_scanning_work_packets: Vec<Box<dyn GCWork<Ruby>>> = vec![
+ Box::new(ScanGCRoots::new(factory.clone())),
+ Box::new(ScanObjspace::new(factory.clone())),
+ ];
+ gc_tls.worker().scheduler().work_buckets[WorkBucketStage::Prepare]
+ .bulk_add(root_scanning_work_packets);
+
+ // Generate WB-unprotected roots scanning work packets
+
+ 'gen_wb_unprotected_work: {
+ let is_nursery_gc = (crate::mmtk().get_plan().generational())
+ .is_some_and(|gen| gen.is_current_gc_nursery());
+ if !is_nursery_gc {
+ break 'gen_wb_unprotected_work;
+ }
+
+ let vecs = {
+ let guard = crate::binding()
+ .wb_unprotected_objects
+ .try_lock()
+ .expect("Someone is holding the lock of wb_unprotected_objects?");
+ if guard.is_empty() {
+ break 'gen_wb_unprotected_work;
+ }
+
+ let mut collector = ChunkedVecCollector::new(128);
+ collector.extend(guard.iter().copied());
+ collector.into_vecs()
+ };
+
+ let packets = vecs
+ .into_iter()
+ .map(|objects| {
+ let factory = factory.clone();
+ Box::new(ScanWbUnprotectedRoots { factory, objects }) as _
+ })
+ .collect::<Vec<_>>();
+
+ gc_tls.worker().scheduler().work_buckets[WorkBucketStage::Prepare].bulk_add(packets);
+ }
+ }
+
+ fn supports_return_barrier() -> bool {
+ false
+ }
+
+ fn prepare_for_roots_re_scanning() {
+ todo!()
+ }
+
+ fn process_weak_refs(
+ worker: &mut GCWorker<Ruby>,
+ tracer_context: impl mmtk::vm::ObjectTracerContext<Ruby>,
+ ) -> bool {
+ crate::binding()
+ .weak_proc
+ .process_weak_stuff(worker, tracer_context);
+ crate::binding().pinning_registry.cleanup(worker);
+ false
+ }
+
+ fn forward_weak_refs(
+ _worker: &mut GCWorker<Ruby>,
+ _tracer_context: impl mmtk::vm::ObjectTracerContext<Ruby>,
+ ) {
+ panic!("We can't use MarkCompact in Ruby.");
+ }
+}
+
+impl VMScanning {
+ const OBJECT_BUFFER_SIZE: usize = 4096;
+
+ fn collect_object_roots_in<F: FnOnce()>(
+ root_scan_kind: &str,
+ gc_tls: &mut GCThreadTLS,
+ factory: &mut impl RootsWorkFactory<RubySlot>,
+ callback: F,
+ ) {
+ let mut buffer: Vec<ObjectReference> = Vec::new();
+ let visit_object = |_, object: ObjectReference, pin| {
+ debug!(
+ "[{}] Visiting object: {}{}",
+ root_scan_kind,
+ object,
+ if pin {
+ "(unmovable root)"
+ } else {
+ "(movable, but we pin it anyway)"
+ }
+ );
+ debug_assert!(
+ mmtk::memory_manager::is_mmtk_object(object.to_raw_address()).is_some(),
+ "Root does not point to MMTk object. object: {object}"
+ );
+ buffer.push(object);
+ if buffer.len() >= Self::OBJECT_BUFFER_SIZE {
+ factory.create_process_pinning_roots_work(std::mem::take(&mut buffer));
+ }
+ object
+ };
+ gc_tls
+ .object_closure
+ .set_temporarily_and_run_code(visit_object, callback);
+
+ if !buffer.is_empty() {
+ factory.create_process_pinning_roots_work(buffer);
+ }
+ }
+}
+
+trait GlobaRootScanningWork {
+ type F: RootsWorkFactory<RubySlot>;
+ const NAME: &'static str;
+
+ fn new(factory: Self::F) -> Self;
+ fn scan_roots();
+ fn roots_work_factory(&mut self) -> &mut Self::F;
+
+ fn do_work(&mut self, worker: &mut GCWorker<Ruby>, _mmtk: &'static mmtk::MMTK<Ruby>) {
+ let gc_tls = unsafe { GCThreadTLS::from_vwt_check(worker.tls) };
+
+ let factory = self.roots_work_factory();
+
+ VMScanning::collect_object_roots_in(Self::NAME, gc_tls, factory, || {
+ Self::scan_roots();
+ });
+ }
+}
+
+macro_rules! define_global_root_scanner {
+ ($name: ident, $code: expr) => {
+ struct $name<F: RootsWorkFactory<RubySlot>> {
+ factory: F,
+ }
+ impl<F: RootsWorkFactory<RubySlot>> GlobaRootScanningWork for $name<F> {
+ type F = F;
+ const NAME: &'static str = stringify!($name);
+ fn new(factory: Self::F) -> Self {
+ Self { factory }
+ }
+ fn scan_roots() {
+ $code
+ }
+ fn roots_work_factory(&mut self) -> &mut Self::F {
+ &mut self.factory
+ }
+ }
+ impl<F: RootsWorkFactory<RubySlot>> GCWork<Ruby> for $name<F> {
+ fn do_work(&mut self, worker: &mut GCWorker<Ruby>, mmtk: &'static mmtk::MMTK<Ruby>) {
+ GlobaRootScanningWork::do_work(self, worker, mmtk);
+ }
+ }
+ };
+}
+
+define_global_root_scanner!(ScanGCRoots, {
+ (crate::upcalls().scan_gc_roots)();
+});
+
+define_global_root_scanner!(ScanObjspace, {
+ (crate::upcalls().scan_objspace)();
+});
+
+struct ScanWbUnprotectedRoots<F: RootsWorkFactory<RubySlot>> {
+ factory: F,
+ objects: Vec<ObjectReference>,
+}
+
+impl<F: RootsWorkFactory<RubySlot>> GCWork<Ruby> for ScanWbUnprotectedRoots<F> {
+ fn do_work(&mut self, worker: &mut GCWorker<Ruby>, _mmtk: &'static mmtk::MMTK<Ruby>) {
+ let gc_tls = unsafe { GCThreadTLS::from_vwt_check(worker.tls) };
+ VMScanning::collect_object_roots_in("wb_unprot_roots", gc_tls, &mut self.factory, || {
+ for object in self.objects.iter().copied() {
+ if object.is_reachable() {
+ debug!("[wb_unprot_roots] Visiting WB-unprotected object (parent): {object}");
+ (upcalls().call_gc_mark_children)(object);
+
+ if crate::mmtk().get_plan().current_gc_may_move_object() {
+ (upcalls().update_object_references)(object);
+ }
+ } else {
+ debug!(
+ "[wb_unprot_roots] Skipping young WB-unprotected object (parent): {object}"
+ );
+ }
+ }
+ });
+ }
+}
diff --git a/gc/mmtk/src/utils.rs b/gc/mmtk/src/utils.rs
new file mode 100644
index 0000000000..d1979eaf58
--- /dev/null
+++ b/gc/mmtk/src/utils.rs
@@ -0,0 +1,161 @@
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
+
+use atomic_refcell::AtomicRefCell;
+use mmtk::scheduler::GCWork;
+use mmtk::scheduler::GCWorker;
+use mmtk::scheduler::WorkBucketStage;
+
+use crate::Ruby;
+use sysinfo::System;
+
+pub struct ChunkedVecCollector<T> {
+ vecs: Vec<Vec<T>>,
+ current_vec: Vec<T>,
+ chunk_size: usize,
+}
+
+impl<T> ChunkedVecCollector<T> {
+ pub fn new(chunk_size: usize) -> Self {
+ Self {
+ vecs: vec![],
+ current_vec: Vec::with_capacity(chunk_size),
+ chunk_size,
+ }
+ }
+
+ pub fn add(&mut self, item: T) {
+ self.current_vec.push(item);
+ if self.current_vec.len() == self.chunk_size {
+ self.flush();
+ }
+ }
+
+ fn flush(&mut self) {
+ let new_vec = Vec::with_capacity(self.chunk_size);
+ let old_vec = std::mem::replace(&mut self.current_vec, new_vec);
+ self.vecs.push(old_vec);
+ }
+
+ pub fn into_vecs(mut self) -> Vec<Vec<T>> {
+ if !self.current_vec.is_empty() {
+ self.flush();
+ }
+ self.vecs
+ }
+}
+
+impl<A> Extend<A> for ChunkedVecCollector<A> {
+ fn extend<T: IntoIterator<Item = A>>(&mut self, iter: T) {
+ for item in iter {
+ self.add(item);
+ }
+ }
+}
+
+pub struct AfterAll {
+ counter: AtomicUsize,
+ stage: WorkBucketStage,
+ packets: AtomicRefCell<Vec<Box<dyn GCWork<Ruby>>>>,
+}
+
+unsafe impl Sync for AfterAll {}
+
+impl AfterAll {
+ pub fn new(stage: WorkBucketStage) -> Self {
+ Self {
+ counter: AtomicUsize::new(0),
+ stage,
+ packets: AtomicRefCell::new(vec![]),
+ }
+ }
+
+ pub fn add_packets(&self, mut packets: Vec<Box<dyn GCWork<Ruby>>>) {
+ let mut borrow = self.packets.borrow_mut();
+ borrow.append(&mut packets);
+ }
+
+ pub fn count_up(&self, n: usize) {
+ self.counter.fetch_add(n, Ordering::SeqCst);
+ }
+
+ pub fn count_down(&self, worker: &mut GCWorker<Ruby>) {
+ let old = self.counter.fetch_sub(1, Ordering::SeqCst);
+ if old == 1 {
+ let packets = {
+ let mut borrow = self.packets.borrow_mut();
+ std::mem::take(borrow.as_mut())
+ };
+ worker.scheduler().work_buckets[self.stage].bulk_add(packets);
+ }
+ }
+}
+
+pub fn default_heap_max() -> usize {
+ let mut s = System::new();
+ s.refresh_memory();
+ s.total_memory()
+ .checked_mul(80)
+ .and_then(|v| v.checked_div(100))
+ .expect("Invalid Memory size") as usize
+}
+
+pub fn parse_capacity(input: &str) -> Option<usize> {
+ let trimmed = input.trim();
+
+ const KIBIBYTE: usize = 1024;
+ const MEBIBYTE: usize = 1024 * KIBIBYTE;
+ const GIBIBYTE: usize = 1024 * MEBIBYTE;
+
+ let (number, suffix) = if let Some(pos) = trimmed.find(|c: char| !c.is_numeric()) {
+ trimmed.split_at(pos)
+ } else {
+ (trimmed, "")
+ };
+
+ let Ok(v) = number.parse::<usize>() else {
+ return None;
+ };
+
+ match suffix {
+ "GiB" => Some(v * GIBIBYTE),
+ "MiB" => Some(v * MEBIBYTE),
+ "KiB" => Some(v * KIBIBYTE),
+ "" => Some(v),
+ _ => None,
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ #[test]
+ fn test_parse_capacity_parses_bare_bytes() {
+ assert_eq!(Some(1234), parse_capacity("1234"));
+ }
+
+ #[test]
+ fn test_parse_capacity_parses_kibibytes() {
+ assert_eq!(Some(10240), parse_capacity("10KiB"));
+ }
+
+ #[test]
+ fn test_parse_capacity_parses_mebibytes() {
+ assert_eq!(Some(10485760), parse_capacity("10MiB"))
+ }
+
+ #[test]
+ fn test_parse_capacity_parses_gibibytes() {
+ assert_eq!(Some(10737418240), parse_capacity("10GiB"))
+ }
+
+ #[test]
+ fn test_parse_capacity_parses_nonsense_values() {
+ assert_eq!(None, parse_capacity("notanumber"));
+ assert_eq!(None, parse_capacity("5tartswithanumber"));
+ assert_eq!(None, parse_capacity("number1nthemiddle"));
+ assert_eq!(None, parse_capacity("numberattheend111"));
+ assert_eq!(None, parse_capacity("mult1pl3numb3r5"));
+ }
+}
diff --git a/gc/mmtk/src/weak_proc.rs b/gc/mmtk/src/weak_proc.rs
new file mode 100644
index 0000000000..d38dbe04a4
--- /dev/null
+++ b/gc/mmtk/src/weak_proc.rs
@@ -0,0 +1,328 @@
+use std::sync::Mutex;
+
+use mmtk::scheduler::GCWork;
+use mmtk::scheduler::GCWorker;
+use mmtk::scheduler::WorkBucketStage;
+use mmtk::util::ObjectReference;
+use mmtk::vm::ObjectTracerContext;
+
+use crate::abi::GCThreadTLS;
+use crate::upcalls;
+use crate::Ruby;
+
+pub struct WeakProcessor {
+ non_parallel_obj_free_candidates: Mutex<Vec<ObjectReference>>,
+ parallel_obj_free_candidates: Vec<Mutex<Vec<ObjectReference>>>,
+
+ /// Objects that needs `obj_free` called when dying.
+ /// If it is a bottleneck, replace it with a lock-free data structure,
+ /// or add candidates in batch.
+ weak_references: Mutex<Vec<ObjectReference>>,
+}
+
+impl Default for WeakProcessor {
+ fn default() -> Self {
+ Self::new()
+ }
+}
+
+impl WeakProcessor {
+ pub fn new() -> Self {
+ Self {
+ non_parallel_obj_free_candidates: Mutex::new(Vec::new()),
+ parallel_obj_free_candidates: vec![Mutex::new(Vec::new())],
+ weak_references: Mutex::new(Vec::new()),
+ }
+ }
+
+ pub fn init_parallel_obj_free_candidates(&mut self, num_workers: usize) {
+ debug_assert_eq!(self.parallel_obj_free_candidates.len(), 1);
+
+ for _ in 1..num_workers {
+ self.parallel_obj_free_candidates
+ .push(Mutex::new(Vec::new()));
+ }
+ }
+
+ /// Add a batch of objects as candidates for `obj_free`.
+ ///
+ /// Amortizes mutex acquisition over the entire batch. Called when a
+ /// mutator's local buffer is flushed (buffer full or stop-the-world).
+ pub fn add_obj_free_candidates_batch(
+ &self,
+ objects: &[ObjectReference],
+ can_parallel_free: bool,
+ ) {
+ if objects.is_empty() {
+ return;
+ }
+
+ if can_parallel_free {
+ let num_buckets = self.parallel_obj_free_candidates.len();
+ for idx in 0..num_buckets {
+ let mut bucket = self.parallel_obj_free_candidates[idx].lock().unwrap();
+ for (i, &obj) in objects.iter().enumerate() {
+ if i % num_buckets == idx {
+ bucket.push(obj);
+ }
+ }
+ }
+ } else {
+ self.non_parallel_obj_free_candidates
+ .lock()
+ .unwrap()
+ .extend_from_slice(objects);
+ }
+ }
+
+ pub fn get_all_obj_free_candidates(&self) -> Vec<ObjectReference> {
+ // let mut obj_free_candidates = self.obj_free_candidates.lock().unwrap();
+ let mut all_obj_free_candidates = self
+ .non_parallel_obj_free_candidates
+ .lock()
+ .unwrap()
+ .to_vec();
+
+ for candidates_mutex in &self.parallel_obj_free_candidates {
+ all_obj_free_candidates.extend(candidates_mutex.lock().unwrap().to_vec());
+ }
+
+ std::mem::take(all_obj_free_candidates.as_mut())
+ }
+
+ pub fn add_weak_reference(&self, object: ObjectReference) {
+ let mut weak_references = self.weak_references.lock().unwrap();
+ weak_references.push(object);
+ }
+
+ pub fn weak_references_count(&self) -> usize {
+ self.weak_references.lock().unwrap().len()
+ }
+
+ pub fn process_weak_stuff(
+ &self,
+ worker: &mut GCWorker<Ruby>,
+ _tracer_context: impl ObjectTracerContext<Ruby>,
+ ) {
+ worker.add_work(
+ WorkBucketStage::VMRefClosure,
+ ProcessNonParallelObjFreeCanadidates {},
+ );
+
+ for index in 0..self.parallel_obj_free_candidates.len() {
+ worker.add_work(
+ WorkBucketStage::VMRefClosure,
+ ProcessParallelObjFreeCandidates { index },
+ );
+ }
+
+ worker.add_work(WorkBucketStage::VMRefClosure, ProcessWeakReferences);
+
+ worker.add_work(WorkBucketStage::Prepare, UpdateFinalizerObjIdTables);
+
+ let global_tables_count = (crate::upcalls().global_tables_count)();
+ let work_packets = (0..global_tables_count)
+ .map(|i| Box::new(UpdateGlobalTables { idx: i }) as _)
+ .collect();
+
+ worker.scheduler().work_buckets[WorkBucketStage::VMRefClosure].bulk_add(work_packets);
+
+ worker.scheduler().work_buckets[WorkBucketStage::VMRefClosure]
+ .bulk_add(vec![Box::new(UpdateWbUnprotectedObjectsList) as _]);
+ }
+}
+
+fn process_obj_free_candidates(obj_free_candidates: &mut Vec<ObjectReference>) {
+ // Process obj_free
+ let mut new_candidates = Vec::new();
+
+ for object in obj_free_candidates.iter().copied() {
+ if object.is_reachable() {
+ // Forward and add back to the candidate list.
+ let new_object = object.forward();
+ trace!("Forwarding obj_free candidate: {object} -> {new_object}");
+ new_candidates.push(new_object);
+ } else {
+ (upcalls().call_obj_free)(object);
+ }
+ }
+
+ *obj_free_candidates = new_candidates;
+}
+
+struct ProcessParallelObjFreeCandidates {
+ index: usize,
+}
+
+impl GCWork<Ruby> for ProcessParallelObjFreeCandidates {
+ fn do_work(&mut self, _worker: &mut GCWorker<Ruby>, _mmtk: &'static mmtk::MMTK<Ruby>) {
+ let mut obj_free_candidates = crate::binding().weak_proc.parallel_obj_free_candidates
+ [self.index]
+ .try_lock()
+ .expect("Lock for parallel_obj_free_candidates should not be held");
+
+ process_obj_free_candidates(&mut obj_free_candidates);
+ }
+}
+
+struct ProcessNonParallelObjFreeCanadidates;
+
+impl GCWork<Ruby> for ProcessNonParallelObjFreeCanadidates {
+ fn do_work(&mut self, _worker: &mut GCWorker<Ruby>, _mmtk: &'static mmtk::MMTK<Ruby>) {
+ let mut obj_free_candidates = crate::binding()
+ .weak_proc
+ .non_parallel_obj_free_candidates
+ .try_lock()
+ .expect("Lock for non_parallel_obj_free_candidates should not be held");
+
+ process_obj_free_candidates(&mut obj_free_candidates);
+ }
+}
+
+struct ProcessWeakReferences;
+
+impl GCWork<Ruby> for ProcessWeakReferences {
+ fn do_work(&mut self, worker: &mut GCWorker<Ruby>, _mmtk: &'static mmtk::MMTK<Ruby>) {
+ if crate::mmtk().get_plan().current_gc_may_move_object() {
+ let gc_tls: &mut GCThreadTLS = unsafe { GCThreadTLS::from_vwt_check(worker.tls) };
+
+ let visit_object = |_worker, target_object: ObjectReference, _pin| {
+ debug_assert!(
+ mmtk::memory_manager::is_mmtk_object(target_object.to_raw_address()).is_some(),
+ "Destination is not an MMTk object"
+ );
+
+ target_object
+ .get_forwarded_object()
+ .unwrap_or(target_object)
+ };
+
+ gc_tls
+ .object_closure
+ .set_temporarily_and_run_code(visit_object, || {
+ self.process_weak_references(true);
+ })
+ } else {
+ self.process_weak_references(false);
+ }
+ }
+}
+
+impl ProcessWeakReferences {
+ fn process_weak_references(&mut self, moving_gc: bool) {
+ let mut weak_references = crate::binding()
+ .weak_proc
+ .weak_references
+ .try_lock()
+ .expect("Mutators should not be holding the lock.");
+
+ weak_references.retain_mut(|object_ptr| {
+ let object = object_ptr.get_forwarded_object().unwrap_or(*object_ptr);
+
+ if object != *object_ptr {
+ *object_ptr = object;
+ }
+
+ if object.is_reachable() {
+ (upcalls().handle_weak_references)(object, moving_gc);
+
+ true
+ } else {
+ false
+ }
+ });
+ }
+}
+
+trait GlobalTableProcessingWork {
+ fn process_table(&mut self);
+
+ fn do_work(&mut self, worker: &mut GCWorker<Ruby>, _mmtk: &'static mmtk::MMTK<Ruby>) {
+ let gc_tls = unsafe { GCThreadTLS::from_vwt_check(worker.tls) };
+
+ // `hash_foreach_replace` depends on `gb_object_moved_p` which has to have the semantics
+ // of `trace_object` due to the way it is used in `UPDATE_IF_MOVED`.
+ let forward_object = |_worker, object: ObjectReference, _pin| {
+ debug_assert!(
+ mmtk::memory_manager::is_mmtk_object(object.to_raw_address()).is_some(),
+ "{object} is not an MMTk object"
+ );
+ let result = object.forward();
+ trace!("Forwarding reference: {object} -> {result}");
+ result
+ };
+
+ gc_tls
+ .object_closure
+ .set_temporarily_and_run_code(forward_object, || {
+ self.process_table();
+ });
+ }
+}
+
+struct UpdateFinalizerObjIdTables;
+impl GlobalTableProcessingWork for UpdateFinalizerObjIdTables {
+ fn process_table(&mut self) {
+ (crate::upcalls().update_finalizer_table)();
+ }
+}
+impl GCWork<Ruby> for UpdateFinalizerObjIdTables {
+ fn do_work(&mut self, worker: &mut GCWorker<Ruby>, mmtk: &'static mmtk::MMTK<Ruby>) {
+ GlobalTableProcessingWork::do_work(self, worker, mmtk);
+ }
+}
+
+struct UpdateGlobalTables {
+ idx: i32,
+}
+impl GlobalTableProcessingWork for UpdateGlobalTables {
+ fn process_table(&mut self) {
+ (crate::upcalls().update_global_tables)(
+ self.idx,
+ crate::mmtk().get_plan().current_gc_may_move_object(),
+ )
+ }
+}
+impl GCWork<Ruby> for UpdateGlobalTables {
+ fn do_work(&mut self, worker: &mut GCWorker<Ruby>, mmtk: &'static mmtk::MMTK<Ruby>) {
+ GlobalTableProcessingWork::do_work(self, worker, mmtk);
+ }
+}
+
+struct UpdateWbUnprotectedObjectsList;
+
+impl GCWork<Ruby> for UpdateWbUnprotectedObjectsList {
+ fn do_work(&mut self, _worker: &mut GCWorker<Ruby>, _mmtk: &'static mmtk::MMTK<Ruby>) {
+ let mut objects = crate::binding().wb_unprotected_objects.try_lock().expect(
+ "Someone is holding the lock of wb_unprotected_objects during weak processing phase?",
+ );
+
+ let old_objects = std::mem::take(&mut *objects);
+
+ debug!("Updating {} WB-unprotected objects", old_objects.len());
+
+ for object in old_objects {
+ if object.is_reachable() {
+ // Forward and add back to the candidate list.
+ let new_object = object.forward();
+ trace!("Forwarding WB-unprotected object: {object} -> {new_object}");
+ objects.insert(new_object);
+ } else {
+ trace!("Removing WB-unprotected object from list: {object}");
+ }
+ }
+
+ debug!("Retained {} live WB-unprotected objects.", objects.len());
+ }
+}
+
+// Provide a shorthand `object.forward()`.
+trait Forwardable {
+ fn forward(&self) -> Self;
+}
+
+impl Forwardable for ObjectReference {
+ fn forward(&self) -> Self {
+ self.get_forwarded_object().unwrap_or(*self)
+ }
+}
diff --git a/gc/wbcheck/extconf.rb b/gc/wbcheck/extconf.rb
new file mode 100644
index 0000000000..18b32d820d
--- /dev/null
+++ b/gc/wbcheck/extconf.rb
@@ -0,0 +1,3 @@
+require_relative '../extconf_base'
+
+create_gc_makefile("wbcheck")
diff --git a/gc/wbcheck/wbcheck.c b/gc/wbcheck/wbcheck.c
new file mode 100644
index 0000000000..a7d4cd6ccf
--- /dev/null
+++ b/gc/wbcheck/wbcheck.c
@@ -0,0 +1,1936 @@
+#include "internal.h"
+#include "ruby/ruby.h"
+#include "ruby/assert.h"
+#include "ruby/atomic.h"
+#include "ruby/debug.h"
+#include "ruby/internal/core/rbasic.h"
+#include "ruby/st.h"
+#include "internal/object.h"
+#include "internal/array.h"
+#include "internal/class.h"
+
+#include "ruby/thread.h"
+#include "gc/gc.h"
+#include "gc/gc_impl.h"
+
+#include <stdbool.h>
+#include <stdarg.h>
+
+// Debug output control
+static bool wbcheck_debug_enabled = false;
+
+// Verification after write barrier control
+static bool wbcheck_verify_after_wb_enabled = false;
+
+// Useless write barrier warning control
+static bool wbcheck_warn_useless_wb_enabled = false;
+
+static void
+wbcheck_debug(const char *format, ...)
+{
+ if (!wbcheck_debug_enabled) return;
+
+ va_list args;
+ va_start(args, format);
+ vfprintf(stderr, format, args);
+ va_end(args);
+}
+
+#define WBCHECK_DEBUG(...) do { \
+ if (wbcheck_debug_enabled) { \
+ wbcheck_debug(__VA_ARGS__); \
+ } \
+} while (0)
+
+static void
+wbcheck_debug_obj_info_dump(VALUE obj)
+{
+ if (!wbcheck_debug_enabled) return;
+ char buff[0x100];
+ fprintf(stderr, "%s\n", rb_raw_obj_info(buff, sizeof(buff), obj));
+}
+
+// Forward declaration
+static void lock_and_maybe_gc(void *objspace_ptr);
+static void force_gc(void *objspace_ptr);
+
+// Configure wbcheck from environment variables
+static void
+wbcheck_configure_from_env(void)
+{
+ // Configure debug output based on environment variable
+ const char *debug_env = getenv("WBCHECK_DEBUG");
+ if (debug_env && (strcmp(debug_env, "1") == 0 || strcmp(debug_env, "true") == 0)) {
+ wbcheck_debug_enabled = true;
+ }
+
+ // Configure verification after write barrier based on environment variable
+ const char *verify_after_wb_env = getenv("WBCHECK_VERIFY_AFTER_WB");
+ if (verify_after_wb_env && (strcmp(verify_after_wb_env, "1") == 0 || strcmp(verify_after_wb_env, "true") == 0)) {
+ wbcheck_verify_after_wb_enabled = true;
+ }
+
+ // Configure useless write barrier warnings based on environment variable
+ const char *warn_useless_wb_env = getenv("WBCHECK_WARN_USELESS_WB");
+ if (warn_useless_wb_env && (strcmp(warn_useless_wb_env, "1") == 0 || strcmp(warn_useless_wb_env, "true") == 0)) {
+ wbcheck_warn_useless_wb_enabled = true;
+ }
+}
+
+// Define same heap sizes as the default GC
+static size_t heap_sizes[] = {
+ 32,
+ 40,
+ 48,
+ 56,
+ 64,
+ 72,
+ 80,
+ 96,
+ 128,
+ 160,
+ 256,
+ 512,
+ 640,
+ 768,
+ 1024,
+ 0
+};
+
+#define HEAP_COUNT ((int)(sizeof(heap_sizes) / sizeof(heap_sizes[0])) - 1)
+#define MAX_HEAP_SIZE (heap_sizes[(HEAP_COUNT) - 1])
+
+// Object states for verification tracking
+typedef enum {
+ WBCHECK_STATE_CLEAR, // Just allocated or writebarrier_remember, needs reference capture
+ WBCHECK_STATE_MARKED, // Has valid snapshot, ready for normal operation
+ WBCHECK_STATE_DIRTY // Has seen writebarrier since last snapshot, queued for verification
+} wbcheck_object_state_t;
+
+// Tri-color marking colors
+typedef enum {
+ WBCHECK_COLOR_WHITE, // Unmarked - will be swept
+ WBCHECK_COLOR_GRAY, // Marked but children not processed
+ WBCHECK_COLOR_BLACK // Marked and children processed
+} wbcheck_color_t;
+
+// GC phases
+typedef enum {
+ WBCHECK_PHASE_MUTATOR, // Normal execution
+ WBCHECK_PHASE_SNAPSHOT, // Collecting references for verification
+ WBCHECK_PHASE_FULL_GC // Marking objects during full GC
+} wbcheck_phase_t;
+
+// List of objects
+typedef struct {
+ VALUE *items;
+ size_t count;
+ size_t capacity;
+} wbcheck_object_list_t;
+
+// Helper functions for object list
+static wbcheck_object_list_t *
+wbcheck_object_list_init_with_capacity(size_t capacity)
+{
+ wbcheck_object_list_t *list = calloc(1, sizeof(wbcheck_object_list_t));
+ if (!list) rb_bug("wbcheck: failed to allocate object list structure");
+
+ if (capacity < 4) capacity = 4;
+ list->items = malloc(capacity * sizeof(VALUE));
+ if (!list->items) rb_bug("wbcheck: failed to allocate object list array");
+ list->capacity = capacity;
+ list->count = 0;
+ return list;
+}
+
+static wbcheck_object_list_t *
+wbcheck_object_list_init(void)
+{
+ return wbcheck_object_list_init_with_capacity(4);
+}
+
+static void
+wbcheck_object_list_append(wbcheck_object_list_t *list, VALUE obj)
+{
+ if (list->count >= list->capacity) {
+ size_t new_capacity = list->capacity == 0 ? 4 : list->capacity * 2;
+ VALUE *new_items = realloc(list->items, new_capacity * sizeof(VALUE));
+ if (!new_items) rb_bug("wbcheck: failed to reallocate object list array");
+ list->items = new_items;
+ list->capacity = new_capacity;
+ }
+ list->items[list->count++] = obj;
+}
+
+static void
+wbcheck_object_list_free(wbcheck_object_list_t *list)
+{
+ if (!list) return;
+ if (list->items) {
+ free(list->items);
+ }
+ free(list);
+}
+
+static void
+wbcheck_object_list_debug_print(wbcheck_object_list_t *list)
+{
+ if (!wbcheck_debug_enabled) return;
+ for (size_t i = 0; i < list->count; i++) {
+ char buff[0x100];
+ fprintf(stderr, "-> %s\n", rb_raw_obj_info(buff, sizeof(buff), list->items[i]));
+ }
+}
+
+static bool
+wbcheck_object_list_contains(wbcheck_object_list_t *list, VALUE obj)
+{
+ for (size_t i = 0; i < list->count; i++) {
+ if (list->items[i] == obj) {
+ return true;
+ }
+ }
+ return false;
+}
+
+// Information tracked for each object
+typedef struct {
+ size_t alloc_size; // Allocated size (static)
+ bool wb_protected; // Write barrier protection status (static)
+ VALUE finalizers; // Ruby Array of finalizers like [finalizer1, finalizer2, ...]
+ wbcheck_object_list_t *gc_mark_snapshot; // Snapshot of references from last GC mark
+ wbcheck_object_list_t *mark_maybe_snapshot; // Conservative refs reported via mark_maybe; needed for liveness, not verifiable
+ wbcheck_object_list_t *writebarrier_children; // References added via write barriers since last snapshot
+ wbcheck_object_state_t state; // Current state in verification lifecycle
+ wbcheck_color_t color; // Tri-color marking color
+} rb_wbcheck_object_info_t;
+
+// Finalizer job types
+struct wbcheck_final_job {
+ struct wbcheck_final_job *next;
+ enum {
+ WBCHECK_FINAL_JOB_DFREE,
+ WBCHECK_FINAL_JOB_FINALIZE,
+ } kind;
+ union {
+ struct {
+ void (*func)(void *);
+ void *data;
+ } dfree;
+ struct {
+ VALUE finalizer_array;
+ } finalize;
+ } as;
+};
+
+// wbcheck objspace structure to track all objects
+typedef struct {
+ st_table *object_table; // Hash table to track all allocated objects (VALUE -> rb_wbcheck_object_info_t*)
+ wbcheck_object_list_t *objects_to_capture; // Objects that need initial reference capture
+ wbcheck_object_list_t *objects_to_verify; // Objects that need verification after write barriers
+ wbcheck_object_list_t *current_refs; // Current list for collecting references during marking
+ wbcheck_object_list_t *current_maybe_refs; // Current list for collecting mark_maybe references during marking
+ wbcheck_object_list_t *mark_queue; // Queue of gray objects for tri-color marking
+ wbcheck_object_list_t *weak_references; // Objects holding weak references, found during marking
+ wbcheck_phase_t phase; // Current GC phase
+ bool gc_enabled; // Whether GC is allowed to run
+ bool gc_stress; // GC stress mode (run GC on every allocation)
+ size_t gc_threshold; // Trigger GC when object count reaches this
+ size_t missed_write_barrier_parents; // Number of parent objects with missed write barriers
+ size_t missed_write_barrier_children; // Total number of missed write barriers detected
+ size_t simulated_gc_count; // Simulated GC count incremented on each GC.start
+ bool measure_total_time; // Whether to accumulate :time in stats
+ struct wbcheck_final_job *finalizer_jobs; // Linked list of finalizer jobs
+ rb_nativethread_lock_t finalizer_lock; // Protects finalizer_jobs list
+ rb_postponed_job_handle_t finalizer_postponed_job; // Postponed job handle for finalizers
+} rb_wbcheck_objspace_t;
+
+// Global objspace pointer for accessing from obj_slot_size function
+static rb_wbcheck_objspace_t *wbcheck_global_objspace = NULL;
+
+// Forward declarations
+static void wbcheck_foreach_object(rb_wbcheck_objspace_t *objspace, int (*callback)(VALUE obj, rb_wbcheck_object_info_t *info, void *data), void *data);
+static int wbcheck_verify_all_references_callback(VALUE obj, rb_wbcheck_object_info_t *info, void *data);
+static int wbcheck_update_all_snapshots_callback(VALUE obj, rb_wbcheck_object_info_t *info, void *data);
+static void wbcheck_run_finalizers_for_object(VALUE obj, rb_wbcheck_object_info_t *info);
+static void gc_run_finalizers(void *data);
+static void make_final_job(rb_wbcheck_objspace_t *objspace, VALUE obj, VALUE finalizer_array);
+
+// Helper functions for object tracking
+static rb_wbcheck_object_info_t *
+wbcheck_get_object_info(VALUE obj)
+{
+ // Objspace must be initialized by this point
+ GC_ASSERT(wbcheck_global_objspace);
+
+ st_data_t value;
+ if (st_lookup(wbcheck_global_objspace->object_table, (st_data_t)obj, &value)) {
+ return (rb_wbcheck_object_info_t *)value;
+ }
+
+ fprintf(stderr, "wbcheck: object not found in tracking table\n");
+ char buff[0x100];
+ fprintf(stderr, "%s\n", rb_raw_obj_info(buff, sizeof(buff), obj));
+
+ // Force ASAN crash?
+ ((volatile VALUE *)obj)[0];
+
+ // Object not found in tracking table - this should never happen
+ rb_bug("wbcheck: object not found in tracking table");
+}
+
+static void
+wbcheck_report_error(void *objspace_ptr, VALUE parent_obj, wbcheck_object_list_t *current_refs, wbcheck_object_list_t *gc_mark_snapshot, wbcheck_object_list_t *writebarrier_children, wbcheck_object_list_t *missed_refs)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+
+ rb_wbcheck_object_info_t *parent_info = wbcheck_get_object_info(parent_obj);
+
+ size_t snapshot_count = gc_mark_snapshot ? gc_mark_snapshot->count : 0;
+ size_t wb_count = writebarrier_children ? writebarrier_children->count : 0;
+
+ fprintf(stderr, "WBCHECK ERROR: Missed write barrier detected!\n");
+ fprintf(stderr, " Parent object: %p (wb_protected: %s)\n",
+ (void *)parent_obj, parent_info->wb_protected ? "true" : "false");
+ char buff[0x100];
+ fprintf(stderr, " %s\n", rb_raw_obj_info(buff, sizeof(buff), parent_obj));
+ fprintf(stderr, " Reference counts - snapshot: %zu, writebarrier: %zu, current: %zu, missed: %zu\n",
+ snapshot_count, wb_count, current_refs->count, missed_refs->count);
+
+ for (size_t i = 0; i < missed_refs->count; i++) {
+ VALUE missed_ref = missed_refs->items[i];
+ char buff[0x100];
+ fprintf(stderr, " Missing reference to: %p\n %s\n", (void *)missed_ref, rb_raw_obj_info(buff, sizeof(buff), missed_ref));
+ }
+
+ fprintf(stderr, "\n");
+ objspace->missed_write_barrier_parents++;
+ objspace->missed_write_barrier_children += missed_refs->count;
+}
+
+static void
+wbcheck_compare_references(void *objspace_ptr, VALUE parent_obj, wbcheck_object_list_t *current_refs, wbcheck_object_list_t *gc_mark_snapshot, wbcheck_object_list_t *writebarrier_children)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ (void)objspace;
+
+ size_t snapshot_count = gc_mark_snapshot ? gc_mark_snapshot->count : 0;
+ size_t wb_count = writebarrier_children ? writebarrier_children->count : 0;
+
+ WBCHECK_DEBUG("wbcheck: comparing references for object %p\n", (void *)parent_obj);
+ WBCHECK_DEBUG("wbcheck: current refs: %zu, snapshot refs: %zu, wb refs: %zu\n",
+ current_refs->count, snapshot_count, wb_count);
+
+ // Collect missed references (lazily allocated)
+ wbcheck_object_list_t *missed_refs = NULL;
+
+ // Use circular comparison for better performance when lists are mostly similar
+ size_t snapshot_idx = 0;
+
+ // Check each object in current_refs to see if it's in either stored list
+ for (size_t i = 0; i < current_refs->count; i++) {
+ VALUE current_ref = current_refs->items[i];
+
+ // Usually the lists are nearly identical. We take advantage of this by
+ // attempting to loop over both lists in sequence. When the next element
+ // of the snapshot doesn't match the next element of our current_refs,
+ // we'll loop around the list to try to find it and continue from that
+ // match, so any runs of identical items can be matched efficiently.
+ //
+ // Pathologically this is O(N**2), but is O(N * num_changes)
+ bool found_in_snapshot = false;
+ if (gc_mark_snapshot && snapshot_count > 0) {
+ size_t start_idx = snapshot_idx;
+ do {
+ if (gc_mark_snapshot->items[snapshot_idx] == current_ref) {
+ found_in_snapshot = true;
+ snapshot_idx++;
+ if (snapshot_idx >= snapshot_count) snapshot_idx = 0;
+ break;
+ }
+ snapshot_idx++;
+ if (snapshot_idx >= snapshot_count) snapshot_idx = 0;
+ } while (snapshot_idx != start_idx);
+ }
+
+ if (found_in_snapshot) {
+ continue;
+ }
+
+ // Built-in immortal classes can be assigned via RBASIC_SET_CLASS_RAW,
+ // which bypasses the write barrier. They're pinned as VM roots and
+ // can never be collected, so a missing WB to them is harmless.
+ if (RB_TYPE_P(current_ref, T_CLASS) && FL_TEST_RAW(current_ref, RCLASS_IS_ROOT)) {
+ continue;
+ }
+
+ // Self reference... Weird but okay I guess
+ if (current_ref == parent_obj) {
+ continue;
+ }
+
+
+ // Check if reference exists in writebarrier_children
+ if (writebarrier_children && wbcheck_object_list_contains(writebarrier_children, current_ref)) {
+ continue;
+ }
+
+ // If we get here, the reference wasn't found in either list
+ // Lazily allocate missed_refs list on first miss
+ if (!missed_refs) {
+ missed_refs = wbcheck_object_list_init();
+ }
+ wbcheck_object_list_append(missed_refs, current_ref);
+ }
+
+ // Report any errors found
+ if (missed_refs) {
+ wbcheck_report_error(objspace_ptr, parent_obj, current_refs, gc_mark_snapshot, writebarrier_children, missed_refs);
+ wbcheck_object_list_free(missed_refs);
+ }
+}
+
+static void
+wbcheck_register_object(void *objspace_ptr, VALUE obj, size_t alloc_size, bool wb_protected)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ GC_ASSERT(objspace);
+
+ // Allocate and initialize object info structure
+ rb_wbcheck_object_info_t *info = calloc(1, sizeof(rb_wbcheck_object_info_t));
+ if (!info) rb_bug("wbcheck_register_object: failed to allocate object info");
+
+ info->alloc_size = alloc_size;
+ info->wb_protected = wb_protected;
+ info->finalizers = 0; /* No finalizers initially */
+ info->gc_mark_snapshot = NULL; /* No snapshot initially */
+ info->mark_maybe_snapshot = NULL; /* No mark_maybe snapshot initially */
+ info->writebarrier_children = NULL; /* No write barrier children initially */
+ info->state = WBCHECK_STATE_CLEAR; /* Start in clear state */
+ info->color = WBCHECK_COLOR_BLACK; /* Start as black to survive current GC */
+
+ // Store object info in hash table (VALUE -> rb_wbcheck_object_info_t*)
+ st_insert(objspace->object_table, (st_data_t)obj, (st_data_t)info);
+}
+
+static void
+wbcheck_unregister_object(void *objspace_ptr, VALUE obj)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ rb_wbcheck_object_info_t *info;
+
+ if (st_delete(objspace->object_table, (st_data_t *)&obj, (st_data_t *)&info)) {
+ // Free object lists if they were allocated
+ wbcheck_object_list_free(info->gc_mark_snapshot);
+ wbcheck_object_list_free(info->mark_maybe_snapshot);
+ wbcheck_object_list_free(info->writebarrier_children);
+ free(info);
+ } else {
+ rb_bug("wbcheck_unregister_object: object not found in table");
+ }
+}
+
+// Bootup
+void *
+rb_gc_impl_objspace_alloc(void)
+{
+ wbcheck_configure_from_env();
+
+ rb_wbcheck_objspace_t *objspace = calloc(1, sizeof(rb_wbcheck_objspace_t));
+ if (!objspace) rb_bug("wbcheck: failed to allocate objspace");
+
+ objspace->object_table = st_init_numtable();
+ if (!objspace->object_table) {
+ free(objspace);
+ rb_bug("wbcheck: failed to create object table");
+ }
+
+ objspace->objects_to_capture = wbcheck_object_list_init(); // Initialize empty list
+ objspace->objects_to_verify = wbcheck_object_list_init(); // Initialize empty list
+ objspace->current_refs = NULL; // No current refs initially
+ objspace->current_maybe_refs = NULL; // No current maybe refs initially
+ objspace->mark_queue = wbcheck_object_list_init(); // Initialize mark queue
+ objspace->weak_references = wbcheck_object_list_init(); // Initialize weak references array
+ objspace->phase = WBCHECK_PHASE_MUTATOR; // Start in mutator phase
+ objspace->gc_enabled = true; // GC enabled by default (like default GC)
+ objspace->gc_stress = false; // GC stress disabled by default
+ objspace->gc_threshold = 1000; // Start with 1000 objects, will adjust after first GC
+ objspace->missed_write_barrier_parents = 0; // No errors found yet
+ objspace->missed_write_barrier_children = 0; // No errors found yet
+ objspace->simulated_gc_count = 0; // Start with GC count of 0
+ objspace->measure_total_time = true; // On by default
+
+ return objspace;
+}
+
+void
+rb_gc_impl_objspace_init(void *objspace_ptr)
+{
+ rb_wbcheck_objspace_t *objspace = objspace_ptr;
+
+ // Object table is already initialized in objspace_alloc
+ // Set up global objspace pointer for obj_slot_size function
+ wbcheck_global_objspace = objspace;
+
+ // Initialize postponed job for finalizers
+ rb_native_mutex_initialize(&objspace->finalizer_lock);
+ objspace->finalizer_postponed_job = rb_postponed_job_preregister(0, gc_run_finalizers, objspace);
+}
+
+void *
+rb_gc_impl_ractor_cache_alloc(void *objspace_ptr, void *ractor)
+{
+ // Stub implementation
+ return NULL;
+}
+
+void
+rb_gc_impl_set_params(void *objspace_ptr)
+{
+ // Stub implementation
+}
+
+static VALUE
+gc_verify_internal_consistency(VALUE self)
+{
+ return Qnil;
+}
+
+void
+rb_gc_impl_init(void)
+{
+ VALUE gc_constants = rb_hash_new();
+ //rb_hash_aset(gc_constants, ID2SYM(rb_intern("BASE_SLOT_SIZE")), SIZET2NUM(BASE_SLOT_SIZE));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVALUE_SIZE")), SIZET2NUM(sizeof(struct RBasic) + sizeof(VALUE[RBIMPL_RVALUE_EMBED_LEN_MAX])));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RBASIC_SIZE")), SIZET2NUM(sizeof(struct RBasic)));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVALUE_OVERHEAD")), INT2NUM(0));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVARGC_MAX_ALLOCATE_SIZE")), LONG2FIX(MAX_HEAP_SIZE));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("HEAP_COUNT")), LONG2FIX(HEAP_COUNT));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("SIZE_POOL_COUNT")), LONG2FIX(HEAP_COUNT));
+ rb_hash_aset(gc_constants, ID2SYM(rb_intern("RVALUE_OLD_AGE")), INT2FIX(3));
+ OBJ_FREEZE(gc_constants);
+ rb_define_const(rb_mGC, "INTERNAL_CONSTANTS", gc_constants);
+
+ // no-ops for compatibility
+ rb_define_singleton_method(rb_mGC, "verify_internal_consistency", gc_verify_internal_consistency, 0);
+
+ rb_define_singleton_method(rb_mGC, "compact", rb_f_notimplement, 0);
+ rb_define_singleton_method(rb_mGC, "auto_compact", rb_f_notimplement, 0);
+ rb_define_singleton_method(rb_mGC, "auto_compact=", rb_f_notimplement, 1);
+ rb_define_singleton_method(rb_mGC, "latest_compact_info", rb_f_notimplement, 0);
+ rb_define_singleton_method(rb_mGC, "verify_compaction_references", rb_f_notimplement, -1);
+ // Stub implementation
+}
+
+size_t *
+rb_gc_impl_heap_sizes(void *objspace_ptr)
+{
+ return heap_sizes;
+}
+
+// Shutdown
+void
+rb_gc_impl_shutdown_free_objects(void *objspace_ptr)
+{
+ // Stub implementation
+}
+
+void
+rb_gc_impl_objspace_free(void *objspace_ptr)
+{
+ // This should free everything, but we'll just let it leak
+}
+
+void
+rb_gc_impl_ractor_cache_free(void *objspace_ptr, void *cache)
+{
+ // Stub implementation
+}
+
+// GC
+void
+rb_gc_impl_start(void *objspace_ptr, bool full_mark, bool immediate_mark, bool immediate_sweep, bool compact)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ if (objspace) {
+ objspace->simulated_gc_count++;
+ }
+
+ if (!ruby_native_thread_p()) return;
+
+ unsigned int lev = RB_GC_VM_LOCK();
+ rb_gc_vm_barrier();
+ force_gc(objspace_ptr);
+ RB_GC_VM_UNLOCK(lev);
+}
+
+bool
+rb_gc_impl_during_gc_p(void *objspace_ptr)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ return objspace->phase != WBCHECK_PHASE_MUTATOR;
+}
+
+static void
+wbcheck_prepare_heap_i(VALUE obj, void *data)
+{
+ rb_gc_prepare_heap_process_object(obj);
+}
+
+void
+rb_gc_impl_prepare_heap(void *objspace_ptr)
+{
+ rb_gc_impl_each_object(objspace_ptr, wbcheck_prepare_heap_i, NULL);
+}
+
+void
+rb_gc_impl_gc_enable(void *objspace_ptr)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ objspace->gc_enabled = true;
+}
+
+void
+rb_gc_impl_gc_disable(void *objspace_ptr, bool finish_current_gc)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ objspace->gc_enabled = false;
+}
+
+bool
+rb_gc_impl_gc_enabled_p(void *objspace_ptr)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ return objspace->gc_enabled;
+}
+
+void
+rb_gc_impl_stress_set(void *objspace_ptr, VALUE flag)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ objspace->gc_stress = RTEST(flag);
+}
+
+VALUE
+rb_gc_impl_stress_get(void *objspace_ptr)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ return objspace->gc_stress ? Qtrue : Qfalse;
+}
+
+VALUE
+rb_gc_impl_config_get(void *objspace_ptr)
+{
+ return rb_hash_new();
+}
+
+void
+rb_gc_impl_config_set(void *objspace_ptr, VALUE hash)
+{
+}
+
+static wbcheck_object_list_t *
+wbcheck_collect_references_from_object(VALUE obj, rb_wbcheck_object_info_t *info)
+{
+ rb_wbcheck_objspace_t *objspace = wbcheck_global_objspace;
+
+ // Use combination of writebarrier children and last snapshot as capacity hint
+ size_t snapshot_count = (info->gc_mark_snapshot) ? info->gc_mark_snapshot->count : 0;
+ size_t wb_children_count = (info->writebarrier_children) ? info->writebarrier_children->count : 0;
+ size_t capacity_hint = snapshot_count + wb_children_count;
+ wbcheck_object_list_t *new_list = wbcheck_object_list_init_with_capacity(capacity_hint);
+
+ // Set up objspace state for marking. current_maybe_refs is allocated lazily
+ // by rb_gc_impl_mark_maybe, since most objects have no conservative refs.
+ objspace->current_refs = new_list;
+ objspace->current_maybe_refs = NULL;
+ objspace->phase = WBCHECK_PHASE_SNAPSHOT;
+
+ // Use the marking infrastructure to collect references
+ rb_gc_mark_children(objspace, obj);
+
+ // Clean up objspace state
+ objspace->phase = WBCHECK_PHASE_MUTATOR;
+ objspace->current_refs = NULL;
+
+ // Update the mark_maybe snapshot in place. These references don't participate
+ // in verification, but we need to keep them so full GC can mark them gray.
+ wbcheck_object_list_free(info->mark_maybe_snapshot);
+ info->mark_maybe_snapshot = objspace->current_maybe_refs;
+ objspace->current_maybe_refs = NULL;
+
+ if (wbcheck_debug_enabled) {
+ WBCHECK_DEBUG("wbcheck: collected %zu references from %p\n", new_list->count, (void *)obj);
+ char buff[0x100];
+ fprintf(stderr, "%s\n", rb_raw_obj_info(buff, sizeof(buff), obj));
+ wbcheck_object_list_debug_print(new_list);
+ }
+
+ return new_list;
+}
+
+static void
+wbcheck_collect_initial_references(void *objspace_ptr, VALUE obj)
+{
+ WBCHECK_DEBUG("wbcheck: collecting initial references from %p:\n", obj);
+ wbcheck_debug_obj_info_dump(obj);
+
+ // Get the object info and set the initial GC mark snapshot
+ rb_wbcheck_object_info_t *info = wbcheck_get_object_info(obj);
+ wbcheck_object_list_t *new_list = wbcheck_collect_references_from_object(obj, info);
+ RUBY_ASSERT(!info->gc_mark_snapshot);
+ RUBY_ASSERT(info->state == WBCHECK_STATE_CLEAR);
+ info->gc_mark_snapshot = new_list; // Set the initial snapshot
+ info->state = WBCHECK_STATE_MARKED; // Transition to marked state
+}
+
+static void
+wbcheck_verify_object_references(void *objspace_ptr, VALUE obj)
+{
+ rb_wbcheck_object_info_t *info = wbcheck_get_object_info(obj);
+
+ // Ignore objects which are not write barrier protected
+ if (!info->wb_protected) {
+ return;
+ }
+
+ // We hadn't captured initial references
+ if (info->state == WBCHECK_STATE_CLEAR) {
+ RUBY_ASSERT(!info->gc_mark_snapshot);
+ return;
+ }
+
+ WBCHECK_DEBUG("wbcheck: verifying references for object:\n");
+ wbcheck_debug_obj_info_dump(obj);
+
+ // Get the current references from the object
+ wbcheck_object_list_t *current_refs = wbcheck_collect_references_from_object(obj, info);
+
+ // Check for useless write barriers before clearing them
+ if (wbcheck_warn_useless_wb_enabled && info->writebarrier_children) {
+ for (size_t i = 0; i < info->writebarrier_children->count; i++) {
+ VALUE wb_ref = info->writebarrier_children->items[i];
+ if (!wbcheck_object_list_contains(current_refs, wb_ref)) {
+ fprintf(stderr, "WBCHECK WARNING: Potentially useless write barrier detected for object %p\n", (void *)obj);
+ fprintf(stderr, " Write barrier was recorded for reference to %p, but object no longer references it\n", (void *)wb_ref);
+ char buff[0x100];
+ fprintf(stderr, " Parent: %s\n", rb_raw_obj_info(buff, sizeof(buff), obj));
+ fprintf(stderr, " Stale reference: %s\n", rb_raw_obj_info(buff, sizeof(buff), wb_ref));
+ }
+ }
+ }
+
+ // Compare current_refs against both stored lists to detect missed write barriers
+ wbcheck_compare_references(objspace_ptr, obj, current_refs, info->gc_mark_snapshot, info->writebarrier_children);
+
+ // Update the snapshot with current references and clear write barrier children
+ wbcheck_object_list_free(info->gc_mark_snapshot);
+ wbcheck_object_list_free(info->writebarrier_children);
+ info->gc_mark_snapshot = current_refs;
+ info->writebarrier_children = NULL;
+ info->state = WBCHECK_STATE_MARKED; // Back to marked state after verification
+}
+
+// Mark object as gray (add to mark queue)
+static void
+wbcheck_mark_gray(rb_wbcheck_objspace_t *objspace, VALUE obj)
+{
+ if (RB_SPECIAL_CONST_P(obj)) return;
+
+ st_data_t value;
+ if (!st_lookup(objspace->object_table, (st_data_t)obj, &value)) {
+ rb_bug("wbcheck: asked to mark object %p not in our object table", (void *)obj);
+ }
+
+ rb_wbcheck_object_info_t *info = (rb_wbcheck_object_info_t *)value;
+ if (info->color != WBCHECK_COLOR_WHITE) {
+ return; // Already marked
+ }
+
+ info->color = WBCHECK_COLOR_GRAY;
+ wbcheck_object_list_append(objspace->mark_queue, obj);
+
+ if (RB_FL_TEST_RAW(obj, RUBY_FL_WEAK_REFERENCE)) {
+ wbcheck_object_list_append(objspace->weak_references, obj);
+ }
+
+ WBCHECK_DEBUG("wbcheck: marked gray: %p\n", (void *)obj);
+}
+
+// Reset all objects to white
+static int
+st_foreach_reset_white(st_data_t key, st_data_t val, st_data_t arg)
+{
+ rb_wbcheck_object_info_t *info = (rb_wbcheck_object_info_t *)val;
+ info->color = WBCHECK_COLOR_WHITE;
+ return ST_CONTINUE;
+}
+
+// Mark all finalizer arrays to keep them alive during GC
+static int
+st_foreach_mark_finalizers(st_data_t key, st_data_t val, st_data_t arg)
+{
+ rb_wbcheck_object_info_t *info = (rb_wbcheck_object_info_t *)val;
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)arg;
+
+ if (info->finalizers) {
+ wbcheck_mark_gray(objspace, info->finalizers);
+ }
+
+ return ST_CONTINUE;
+}
+
+// Full mark phase using tri-color marking with snapshots
+static void
+wbcheck_mark_phase(rb_wbcheck_objspace_t *objspace)
+{
+ WBCHECK_DEBUG("wbcheck: starting GC mark phase\n");
+
+ objspace->phase = WBCHECK_PHASE_FULL_GC;
+
+ // Clear mark queue and reset all objects to white
+ objspace->mark_queue->count = 0;
+ st_foreach(objspace->object_table, st_foreach_reset_white, 0);
+
+ // Mark all finalizer arrays first to keep them alive
+ st_foreach(objspace->object_table, st_foreach_mark_finalizers, (st_data_t)objspace);
+
+ // Mark finalizer arrays in pending jobs to keep them alive.
+ // No lock needed: all other threads are stopped during GC.
+ struct wbcheck_final_job *job = objspace->finalizer_jobs;
+ while (job != NULL) {
+ switch (job->kind) {
+ case WBCHECK_FINAL_JOB_DFREE:
+ break;
+ case WBCHECK_FINAL_JOB_FINALIZE:
+ wbcheck_mark_gray(objspace, job->as.finalize.finalizer_array);
+ break;
+ default:
+ rb_bug("wbcheck_mark_phase: unknown final job type %d", job->kind);
+ }
+ job = job->next;
+ }
+
+ // Mark roots gray
+ rb_gc_save_machine_context();
+ rb_gc_mark_roots(objspace, NULL);
+
+ // Process gray queue until empty
+ while (objspace->mark_queue->count > 0) {
+ // Get last object from queue (LIFO)
+ VALUE obj = objspace->mark_queue->items[--objspace->mark_queue->count];
+
+ st_data_t value;
+ if (st_lookup(objspace->object_table, (st_data_t)obj, &value)) {
+ rb_wbcheck_object_info_t *info = (rb_wbcheck_object_info_t *)value;
+ if (info->color == WBCHECK_COLOR_GRAY) {
+ // Mark all children from snapshot gray
+ if (info->gc_mark_snapshot) {
+ for (size_t i = 0; i < info->gc_mark_snapshot->count; i++) {
+ wbcheck_mark_gray(objspace, info->gc_mark_snapshot->items[i]);
+ }
+ }
+
+ // Conservatively-scanned children must also be kept alive
+ if (info->mark_maybe_snapshot) {
+ for (size_t i = 0; i < info->mark_maybe_snapshot->count; i++) {
+ wbcheck_mark_gray(objspace, info->mark_maybe_snapshot->items[i]);
+ }
+ }
+
+ // Mark this object black
+ info->color = WBCHECK_COLOR_BLACK;
+ WBCHECK_DEBUG("wbcheck: marked black: %p\n", (void *)obj);
+ }
+ }
+ }
+
+ objspace->phase = WBCHECK_PHASE_MUTATOR;
+
+ WBCHECK_DEBUG("wbcheck: tri-color mark phase complete\n");
+}
+
+// Sweep phase callback - free white objects
+static int
+wbcheck_sweep_callback(st_data_t key, st_data_t val, st_data_t arg, int error)
+{
+ VALUE obj = (VALUE)key;
+ rb_wbcheck_object_info_t *info = (rb_wbcheck_object_info_t *)val;
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)arg;
+
+ if (info->color == WBCHECK_COLOR_WHITE) {
+ WBCHECK_DEBUG("wbcheck: sweeping unmarked object %p\n", (void *)obj);
+
+ rb_gc_event_hook(obj, RUBY_INTERNAL_EVENT_FREEOBJ);
+
+ // Clear weak references first
+ rb_gc_obj_free_vm_weak_references(obj);
+
+ // Queue finalizers for postponed job if they exist
+ if (info->finalizers) {
+ make_final_job(objspace, obj, info->finalizers);
+ rb_postponed_job_trigger(objspace->finalizer_postponed_job);
+ }
+
+ // Call rb_gc_obj_free which handles finalizers/zombies
+ if (rb_gc_obj_free(objspace, obj)) {
+ // Object was actually freed, clean up our tracking
+ wbcheck_object_list_free(info->gc_mark_snapshot);
+ wbcheck_object_list_free(info->mark_maybe_snapshot);
+ wbcheck_object_list_free(info->writebarrier_children);
+ free(info);
+
+ // Free the actual object memory
+ free((void *)obj);
+
+ return ST_DELETE; // Remove from hash table
+ } else {
+ // Object became a zombie - it will be freed by postponed job
+ // Remove from tracking since we can't safely access it anymore
+ wbcheck_object_list_free(info->gc_mark_snapshot);
+ wbcheck_object_list_free(info->mark_maybe_snapshot);
+ wbcheck_object_list_free(info->writebarrier_children);
+ free(info);
+
+ // Free the actual object memory
+ free((void *)obj);
+
+ return ST_DELETE; // Remove from hash table
+ }
+ }
+
+ return ST_CONTINUE; // Keep marked objects
+}
+
+static void
+wbcheck_sweep_phase(rb_wbcheck_objspace_t *objspace)
+{
+ WBCHECK_DEBUG("wbcheck: starting sweep phase\n");
+
+ size_t objects_before = st_table_size(objspace->object_table);
+
+ // Sweep unmarked objects
+ st_foreach_check(objspace->object_table, wbcheck_sweep_callback, (st_data_t)objspace, 0);
+
+ size_t objects_after = st_table_size(objspace->object_table);
+ size_t freed_objects = objects_before - objects_after;
+
+ // Update GC threshold: 2x the live set after GC
+ objspace->gc_threshold = objects_after * 2;
+
+ WBCHECK_DEBUG("wbcheck: sweep phase complete - freed %zu objects (%zu -> %zu), new threshold: %zu\n",
+ freed_objects, objects_before, objects_after, objspace->gc_threshold);
+}
+
+// Process weak references after marking - call rb_gc_handle_weak_references
+// on each object that was flagged with RUBY_FL_WEAK_REFERENCE and collected
+// during the mark phase.
+static void
+wbcheck_process_weak_references(rb_wbcheck_objspace_t *objspace)
+{
+ WBCHECK_DEBUG("wbcheck: processing %zu weak reference objects\n", objspace->weak_references->count);
+
+ for (size_t i = 0; i < objspace->weak_references->count; i++) {
+ VALUE obj = objspace->weak_references->items[i];
+ rb_gc_handle_weak_references(obj);
+ }
+
+ objspace->weak_references->count = 0;
+}
+
+// Full GC: verify all objects then mark from roots
+static void
+wbcheck_full_gc(rb_wbcheck_objspace_t *objspace)
+{
+ WBCHECK_DEBUG("wbcheck: starting full GC\n");
+
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_ENTER);
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_START);
+
+ // First, update snapshots for all objects (verify wb_protected ones)
+ WBCHECK_DEBUG("wbcheck: updating snapshots for all objects\n");
+ wbcheck_foreach_object(objspace, wbcheck_update_all_snapshots_callback, objspace);
+
+ // Now start tri-color marking
+ wbcheck_mark_phase(objspace);
+
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_END_MARK);
+
+ // Process weak references after marking, before sweeping
+ wbcheck_process_weak_references(objspace);
+
+ // Sweep unmarked objects
+ wbcheck_sweep_phase(objspace);
+
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_END_SWEEP);
+ rb_gc_event_hook(0, RUBY_INTERNAL_EVENT_GC_EXIT);
+
+ WBCHECK_DEBUG("wbcheck: full GC complete\n");
+}
+
+static void
+gc_step(void *objspace_ptr, bool force)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+
+ // Not initialized yet
+ if (!objspace) return;
+
+ if (!objspace->gc_enabled && !force) return;
+
+ // Process all objects that need verification after write barriers (if enabled)
+ if (wbcheck_verify_after_wb_enabled) {
+ for (size_t i = 0; i < objspace->objects_to_verify->count; i++) {
+ VALUE obj = objspace->objects_to_verify->items[i];
+ wbcheck_verify_object_references(objspace_ptr, obj);
+ }
+
+ // Clear the list after processing
+ objspace->objects_to_verify->count = 0;
+
+ // If any new errors were detected during verification, exit immediately
+ if (objspace->missed_write_barrier_parents > 0) {
+ rb_bug("wbcheck: missed write barrier detected during immediate verification (WBCHECK_VERIFY_AFTER_WB=1)");
+ }
+ }
+
+ // Process all objects that need initial reference capture
+ for (size_t i = 0; i < objspace->objects_to_capture->count; i++) {
+ VALUE obj = objspace->objects_to_capture->items[i];
+ wbcheck_collect_initial_references(objspace_ptr, obj);
+ }
+
+ // Clear the list after processing
+ objspace->objects_to_capture->count = 0;
+
+ // Run full GC if forced, if we exceed the threshold, or if gc_stress is enabled
+ if (ruby_native_thread_p() &&
+ (force ||
+ (objspace->gc_enabled &&
+ (objspace->gc_stress || st_table_size(objspace->object_table) >= objspace->gc_threshold)))) {
+ wbcheck_full_gc(objspace);
+ }
+
+}
+
+static void
+maybe_gc(void *objspace_ptr)
+{
+ gc_step(objspace_ptr, false);
+}
+
+static void
+force_gc(void *objspace_ptr)
+{
+ gc_step(objspace_ptr, true);
+}
+
+int ruby_thread_has_gvl_p(void);
+
+static void *
+lock_and_maybe_gc_gvl(void *objspace_ptr)
+{
+ unsigned int lev = RB_GC_VM_LOCK();
+ rb_gc_vm_barrier();
+
+ maybe_gc(objspace_ptr);
+
+ RB_GC_VM_UNLOCK(lev);
+ return NULL;
+}
+
+static void
+lock_and_maybe_gc(void *objspace_ptr)
+{
+ if (!ruby_native_thread_p()) return;
+
+ if (!ruby_thread_has_gvl_p()) {
+ rb_thread_call_with_gvl(lock_and_maybe_gc_gvl, objspace_ptr);
+ }
+ else {
+ lock_and_maybe_gc_gvl(objspace_ptr);
+ }
+}
+
+VALUE
+rb_gc_impl_new_obj(void *objspace_ptr, void *cache_ptr, VALUE klass, VALUE flags, bool wb_protected, size_t alloc_size)
+{
+ unsigned int lev = RB_GC_VM_LOCK();
+ rb_gc_vm_barrier();
+
+ // Check if we should trigger GC before allocating
+ maybe_gc(objspace_ptr);
+
+ // Ensure minimum allocation size of BASE_SLOT_SIZE
+ alloc_size = heap_sizes[rb_gc_impl_heap_id_for_size(objspace_ptr, alloc_size)];
+
+ // Allocate memory for the object
+ VALUE *mem = malloc(alloc_size);
+ if (!mem) rb_bug("FIXME: malloc failed");
+
+ // Initialize the object
+ VALUE obj = (VALUE)mem;
+ RBASIC(obj)->flags = flags;
+ *((VALUE *)&RBASIC(obj)->klass) = klass;
+
+ // Register the new object in our tracking table
+ wbcheck_register_object(objspace_ptr, obj, alloc_size, wb_protected);
+
+ // Add this object to the list of objects that need initial reference capture
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ wbcheck_object_list_append(objspace->objects_to_capture, obj);
+
+ RB_GC_VM_UNLOCK(lev);
+ return obj;
+}
+
+size_t
+rb_gc_impl_obj_slot_size(VALUE obj)
+{
+ unsigned int lev = RB_GC_VM_LOCK();
+
+ rb_wbcheck_object_info_t *info = wbcheck_get_object_info(obj);
+ size_t result = info->alloc_size;
+
+ RB_GC_VM_UNLOCK(lev);
+ return result;
+}
+
+size_t
+rb_gc_impl_heap_id_for_size(void *objspace_ptr, size_t size)
+{
+ for (int i = 0; i < HEAP_COUNT; i++) {
+ if (size <= heap_sizes[i]) return i;
+ }
+ rb_bug("size too big");
+}
+
+bool
+rb_gc_impl_size_allocatable_p(size_t size)
+{
+ // Only allow sizes up to the largest heap size
+ return size <= MAX_HEAP_SIZE;
+}
+
+// Malloc
+void *
+rb_gc_impl_malloc(void *objspace_ptr, size_t size, bool gc_allowed)
+{
+ if (gc_allowed) {
+ lock_and_maybe_gc(objspace_ptr);
+ }
+ return malloc(size);
+}
+
+void *
+rb_gc_impl_calloc(void *objspace_ptr, size_t size, bool gc_allowed)
+{
+ if (gc_allowed) {
+ lock_and_maybe_gc(objspace_ptr);
+ }
+ return calloc(1, size);
+}
+
+void *
+rb_gc_impl_realloc(void *objspace_ptr, void *ptr, size_t new_size, size_t old_size, bool gc_allowed)
+{
+ if (gc_allowed) {
+ lock_and_maybe_gc(objspace_ptr);
+ }
+ return realloc(ptr, new_size);
+}
+
+void
+rb_gc_impl_free(void *objspace_ptr, void *ptr, size_t old_size)
+{
+ free(ptr);
+}
+
+void
+rb_gc_impl_adjust_memory_usage(void *objspace_ptr, ssize_t diff)
+{
+ // For wbcheck, we don't track memory usage
+}
+
+// Marking
+static void
+gc_mark(rb_wbcheck_objspace_t *objspace, VALUE obj)
+{
+ WBCHECK_DEBUG("wbcheck: gc_mark called\n");
+ wbcheck_debug_obj_info_dump(obj);
+
+ if (RB_SPECIAL_CONST_P(obj)) return;
+
+ switch (objspace->phase) {
+ case WBCHECK_PHASE_SNAPSHOT:
+ // Collecting references during verification
+ GC_ASSERT(objspace->current_refs);
+ wbcheck_object_list_append(objspace->current_refs, obj);
+ break;
+ case WBCHECK_PHASE_FULL_GC:
+ // Marking during full GC
+ wbcheck_mark_gray(objspace, obj);
+ break;
+ case WBCHECK_PHASE_MUTATOR:
+ // Should not be called during mutator phase
+ rb_bug("wbcheck: gc_mark called during mutator phase");
+ break;
+ }
+}
+
+void
+rb_gc_impl_mark(void *objspace_ptr, VALUE obj)
+{
+ rb_wbcheck_objspace_t *objspace = objspace_ptr;
+ gc_mark(objspace, obj);
+}
+
+void
+rb_gc_impl_mark_and_move(void *objspace_ptr, VALUE *ptr)
+{
+ rb_wbcheck_objspace_t *objspace = objspace_ptr;
+ gc_mark(objspace, *ptr);
+}
+
+void
+rb_gc_impl_mark_and_pin(void *objspace_ptr, VALUE obj)
+{
+ rb_wbcheck_objspace_t *objspace = objspace_ptr;
+ gc_mark(objspace, obj);
+}
+
+void
+rb_gc_impl_mark_maybe(void *objspace_ptr, VALUE obj)
+{
+ rb_wbcheck_objspace_t *objspace = objspace_ptr;
+
+ if (!rb_gc_impl_pointer_to_heap_p(objspace_ptr, (void *)obj)) return;
+
+ switch (objspace->phase) {
+ case WBCHECK_PHASE_SNAPSHOT:
+ // We don't know if this is actually a reference or just a value
+ // that looks like one, so we can't expect a write barrier for it.
+ // Keep it separate from the verifiable refs, but retain it so full
+ // GC can mark the target gray if it does turn out to be live.
+ if (!objspace->current_maybe_refs) {
+ objspace->current_maybe_refs = wbcheck_object_list_init();
+ }
+ wbcheck_object_list_append(objspace->current_maybe_refs, obj);
+ break;
+ case WBCHECK_PHASE_FULL_GC:
+ wbcheck_mark_gray(objspace, obj);
+ break;
+ case WBCHECK_PHASE_MUTATOR:
+ rb_bug("wbcheck: rb_gc_impl_mark_maybe called during mutator phase");
+ break;
+ }
+}
+
+// Weak references
+void
+rb_gc_impl_declare_weak_references(void *objspace_ptr, VALUE obj)
+{
+ FL_SET_RAW(obj, RUBY_FL_WEAK_REFERENCE);
+}
+
+bool
+rb_gc_impl_handle_weak_references_alive_p(void *objspace_ptr, VALUE obj)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+
+ st_data_t value;
+ if (st_lookup(objspace->object_table, (st_data_t)obj, &value)) {
+ rb_wbcheck_object_info_t *info = (rb_wbcheck_object_info_t *)value;
+ return info->color != WBCHECK_COLOR_WHITE;
+ }
+
+ return false;
+}
+
+// Compaction
+void
+rb_gc_impl_register_pinning_obj(void *objspace_ptr, VALUE obj)
+{
+ /* no-op */
+}
+
+bool
+rb_gc_impl_object_moved_p(void *objspace_ptr, VALUE obj)
+{
+ // Stub implementation
+ return false;
+}
+
+VALUE
+rb_gc_impl_location(void *objspace_ptr, VALUE value)
+{
+ // Stub implementation
+ return Qnil;
+}
+
+// Write barriers
+void
+rb_gc_impl_writebarrier(void *objspace_ptr, VALUE a, VALUE b)
+{
+ if (RB_SPECIAL_CONST_P(b)) return;
+
+ unsigned int lev = RB_GC_VM_LOCK_NO_BARRIER();
+
+ rb_wbcheck_objspace_t *objspace = objspace_ptr;
+
+ // Get the object info for the parent object (a)
+ rb_wbcheck_object_info_t *info = wbcheck_get_object_info(a);
+
+ // Only record the write barrier if we have a valid snapshot
+ if (info->state != WBCHECK_STATE_CLEAR) {
+ RUBY_ASSERT(info->gc_mark_snapshot);
+
+ // Initialize writebarrier_children list if it doesn't exist
+ if (!info->writebarrier_children) {
+ info->writebarrier_children = wbcheck_object_list_init();
+ }
+
+ // Add the new reference to the write barrier children list
+ wbcheck_object_list_append(info->writebarrier_children, b);
+
+ WBCHECK_DEBUG("wbcheck: write barrier recorded reference from %p to %p\n", (void *)a, (void *)b);
+
+ // If verification after write barrier is enabled, queue the object for verification
+ if (wbcheck_verify_after_wb_enabled && info->state != WBCHECK_STATE_DIRTY) {
+ WBCHECK_DEBUG("wbcheck: queueing object for verification after write barrier\n");
+ info->state = WBCHECK_STATE_DIRTY; // Mark as dirty
+ wbcheck_object_list_append(objspace->objects_to_verify, a);
+ }
+ } else {
+ WBCHECK_DEBUG("wbcheck: write barrier skipped (snapshot not initialized) from %p to %p\n", (void *)a, (void *)b);
+ }
+
+ RB_GC_VM_UNLOCK_NO_BARRIER(lev);
+}
+
+void
+rb_gc_impl_writebarrier_unprotect(void *objspace_ptr, VALUE obj)
+{
+ WBCHECK_DEBUG("wbcheck: writebarrier_unprotect called on object %p\n", (void *)obj);
+
+ unsigned int lev = RB_GC_VM_LOCK_NO_BARRIER();
+
+ rb_wbcheck_object_info_t *info = wbcheck_get_object_info(obj);
+ info->wb_protected = false;
+
+ RB_GC_VM_UNLOCK_NO_BARRIER(lev);
+}
+
+void
+rb_gc_impl_writebarrier_remember(void *objspace_ptr, VALUE obj)
+{
+ WBCHECK_DEBUG("wbcheck: writebarrier_remember called on object %p\n", (void *)obj);
+
+ unsigned int lev = RB_GC_VM_LOCK_NO_BARRIER();
+
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ rb_wbcheck_object_info_t *info = wbcheck_get_object_info(obj);
+
+ // Clear existing references since they may be stale
+ if (info->state != WBCHECK_STATE_CLEAR) {
+ RUBY_ASSERT(info->gc_mark_snapshot);
+ wbcheck_object_list_free(info->gc_mark_snapshot);
+ info->gc_mark_snapshot = NULL;
+
+ wbcheck_object_list_free(info->mark_maybe_snapshot);
+ info->mark_maybe_snapshot = NULL;
+
+ // Only re-add to objects_to_capture if it had previous snapshot
+ // (new objects don't need to be re-added since they'll be captured at allocation)
+ wbcheck_object_list_append(objspace->objects_to_capture, obj);
+
+ // Also clear write barrier children
+ if (info->writebarrier_children) {
+ wbcheck_object_list_free(info->writebarrier_children);
+ info->writebarrier_children = NULL;
+ }
+
+ // Reset to clear state
+ info->state = WBCHECK_STATE_CLEAR;
+ }
+ RUBY_ASSERT(!info->gc_mark_snapshot);
+ RUBY_ASSERT(!info->mark_maybe_snapshot);
+ RUBY_ASSERT(!info->writebarrier_children);
+
+ RB_GC_VM_UNLOCK_NO_BARRIER(lev);
+}
+
+// Heap walking
+struct wbcheck_foreach_data {
+ int (*callback)(VALUE obj, rb_wbcheck_object_info_t *info, void *data);
+ void *data;
+};
+
+static int
+wbcheck_foreach_object_i(st_data_t key, st_data_t val, st_data_t arg)
+{
+ VALUE obj = (VALUE)key;
+ rb_wbcheck_object_info_t *info = (rb_wbcheck_object_info_t *)val;
+ struct wbcheck_foreach_data *foreach_data = (struct wbcheck_foreach_data *)arg;
+
+ return foreach_data->callback(obj, info, foreach_data->data);
+}
+
+static void
+wbcheck_foreach_object(rb_wbcheck_objspace_t *objspace, int (*callback)(VALUE obj, rb_wbcheck_object_info_t *info, void *data), void *data)
+{
+ struct wbcheck_foreach_data foreach_data = {
+ .callback = callback,
+ .data = data
+ };
+
+ st_foreach(objspace->object_table, wbcheck_foreach_object_i, (st_data_t)&foreach_data);
+}
+
+// Helper to collect all objects into a snapshot list
+static int
+wbcheck_snapshot_collector(st_data_t key, st_data_t val, st_data_t arg)
+{
+ VALUE obj = (VALUE)key;
+ wbcheck_object_list_t *snapshot = (wbcheck_object_list_t *)arg;
+ wbcheck_object_list_append(snapshot, obj);
+ return ST_CONTINUE;
+}
+
+// Take a snapshot of all objects for safe iteration
+static wbcheck_object_list_t *
+wbcheck_take_object_snapshot(rb_wbcheck_objspace_t *objspace)
+{
+ size_t object_count = st_table_size(objspace->object_table);
+ wbcheck_object_list_t *snapshot = wbcheck_object_list_init_with_capacity(object_count);
+ st_foreach(objspace->object_table, wbcheck_snapshot_collector, (st_data_t)snapshot);
+ return snapshot;
+}
+
+
+void
+rb_gc_impl_each_objects(void *objspace_ptr, int (*callback)(void *, void *, size_t, void *), void *data)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ GC_ASSERT(objspace);
+
+ wbcheck_object_list_t *snapshot = wbcheck_take_object_snapshot(objspace);
+
+ for (size_t i = 0; i < snapshot->count; i++) {
+ VALUE obj = snapshot->items[i];
+ st_data_t value;
+ if (st_lookup(objspace->object_table, (st_data_t)obj, &value)) {
+ rb_wbcheck_object_info_t *info = (rb_wbcheck_object_info_t *)value;
+ int result = callback(
+ (void *)obj,
+ (void *)((char *)obj + info->alloc_size),
+ info->alloc_size,
+ data
+ );
+ if (result != 0) break;
+ }
+ }
+
+ wbcheck_object_list_free(snapshot);
+}
+
+void
+rb_gc_impl_each_object(void *objspace_ptr, void (*func)(VALUE obj, void *data), void *data)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ GC_ASSERT(objspace);
+
+ wbcheck_object_list_t *snapshot = wbcheck_take_object_snapshot(objspace);
+
+ for (size_t i = 0; i < snapshot->count; i++) {
+ VALUE obj = snapshot->items[i];
+ st_data_t value;
+ if (st_lookup(objspace->object_table, (st_data_t)obj, &value)) {
+ func(obj, data);
+ }
+ }
+
+ wbcheck_object_list_free(snapshot);
+}
+
+static void
+finalizer_jobs_push(rb_wbcheck_objspace_t *objspace, struct wbcheck_final_job *job)
+{
+ rb_native_mutex_lock(&objspace->finalizer_lock);
+ job->next = objspace->finalizer_jobs;
+ objspace->finalizer_jobs = job;
+ rb_native_mutex_unlock(&objspace->finalizer_lock);
+}
+
+static struct wbcheck_final_job *
+finalizer_jobs_pop(rb_wbcheck_objspace_t *objspace)
+{
+ rb_native_mutex_lock(&objspace->finalizer_lock);
+ struct wbcheck_final_job *job = objspace->finalizer_jobs;
+ if (job) {
+ objspace->finalizer_jobs = job->next;
+ }
+ rb_native_mutex_unlock(&objspace->finalizer_lock);
+ return job;
+}
+
+// Finalizers
+void
+rb_gc_impl_make_zombie(void *objspace_ptr, VALUE obj, void (*dfree)(void *), void *data)
+{
+ if (dfree == NULL) return;
+
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+
+ struct wbcheck_final_job *job = malloc(sizeof(struct wbcheck_final_job));
+ job->kind = WBCHECK_FINAL_JOB_DFREE;
+ job->as.dfree.func = dfree;
+ job->as.dfree.data = data;
+
+ finalizer_jobs_push(objspace, job);
+
+ if (!ruby_free_at_exit_p()) {
+ rb_postponed_job_trigger(objspace->finalizer_postponed_job);
+ }
+
+ WBCHECK_DEBUG("wbcheck: made zombie for object %p with dfree function\n", (void *)obj);
+}
+
+VALUE
+rb_gc_impl_define_finalizer(void *objspace_ptr, VALUE obj, VALUE block)
+{
+ unsigned int lev = RB_GC_VM_LOCK();
+
+ (void)objspace_ptr;
+ rb_wbcheck_object_info_t *info = wbcheck_get_object_info(obj);
+
+ GC_ASSERT(!OBJ_FROZEN(obj));
+
+ RBASIC(obj)->flags |= FL_FINALIZE;
+
+ VALUE table = info->finalizers;
+ VALUE result = block;
+
+ if (!table) {
+ /* First finalizer for this object - store object ID as first element */
+ table = rb_ary_new3(2, rb_obj_id(obj), block);
+ rb_obj_hide(table);
+ info->finalizers = table;
+ } else {
+ /* Check for duplicate finalizers (skip index 0 which is object ID) */
+ long len = RARRAY_LEN(table);
+ long i;
+
+ for (i = 1; i < len; i++) {
+ VALUE recv = RARRAY_AREF(table, i);
+ if (rb_equal(recv, block)) {
+ result = recv; /* Duplicate found, return existing */
+ goto unlock_and_return;
+ }
+ }
+
+ rb_ary_push(table, block);
+ }
+
+unlock_and_return:
+ RB_GC_VM_UNLOCK(lev);
+ return result;
+}
+
+void
+rb_gc_impl_undefine_finalizer(void *objspace_ptr, VALUE obj)
+{
+ unsigned int lev = RB_GC_VM_LOCK();
+
+ (void)objspace_ptr;
+ rb_wbcheck_object_info_t *info = wbcheck_get_object_info(obj);
+
+ GC_ASSERT(!OBJ_FROZEN(obj));
+
+ info->finalizers = 0;
+ FL_UNSET(obj, FL_FINALIZE);
+
+ RB_GC_VM_UNLOCK(lev);
+}
+
+void
+rb_gc_impl_copy_finalizer(void *objspace_ptr, VALUE dest, VALUE obj)
+{
+ (void)objspace_ptr;
+
+ if (!FL_TEST(obj, FL_FINALIZE)) return;
+
+ unsigned int lev = RB_GC_VM_LOCK();
+
+ rb_wbcheck_object_info_t *src_info = wbcheck_get_object_info(obj);
+ rb_wbcheck_object_info_t *dest_info = wbcheck_get_object_info(dest);
+
+ if (src_info->finalizers) {
+ VALUE table = rb_ary_dup(src_info->finalizers);
+ RARRAY_ASET(table, 0, rb_obj_id(dest));
+ rb_obj_hide(table);
+ dest_info->finalizers = table;
+ FL_SET(dest, FL_FINALIZE);
+ }
+
+ RB_GC_VM_UNLOCK(lev);
+}
+
+static VALUE
+wbcheck_get_final(long i, void *data)
+{
+ VALUE table = (VALUE)data;
+
+ return RARRAY_AREF(table, i + 1);
+}
+
+static void
+make_final_job(rb_wbcheck_objspace_t *objspace, VALUE obj, VALUE finalizer_array)
+{
+ RUBY_ASSERT(RB_FL_TEST(obj, FL_FINALIZE));
+ RUBY_ASSERT(RB_BUILTIN_TYPE(finalizer_array) == T_ARRAY);
+
+ RB_FL_UNSET(obj, FL_FINALIZE);
+
+ struct wbcheck_final_job *job = malloc(sizeof(struct wbcheck_final_job));
+ job->kind = WBCHECK_FINAL_JOB_FINALIZE;
+ job->as.finalize.finalizer_array = finalizer_array;
+
+ finalizer_jobs_push(objspace, job);
+}
+
+static void
+gc_run_finalizers(void *data)
+{
+ rb_wbcheck_objspace_t *objspace = data;
+
+ rb_gc_set_pending_interrupt();
+
+ struct wbcheck_final_job *job;
+ while ((job = finalizer_jobs_pop(objspace)) != NULL) {
+ switch (job->kind) {
+ case WBCHECK_FINAL_JOB_DFREE:
+ job->as.dfree.func(job->as.dfree.data);
+ break;
+ case WBCHECK_FINAL_JOB_FINALIZE: {
+ VALUE finalizer_array = job->as.finalize.finalizer_array;
+
+ rb_gc_run_obj_finalizer(
+ RARRAY_AREF(finalizer_array, 0),
+ RARRAY_LEN(finalizer_array) - 1,
+ wbcheck_get_final,
+ (void *)finalizer_array
+ );
+
+ RB_GC_GUARD(finalizer_array);
+ break;
+ }
+ }
+
+ free(job);
+ }
+
+ rb_gc_unset_pending_interrupt();
+}
+
+static void
+wbcheck_run_finalizers_for_object(VALUE obj, rb_wbcheck_object_info_t *info)
+{
+ if (info->finalizers) {
+ VALUE table = info->finalizers;
+ long count = RARRAY_LEN(table) - 1;
+ rb_gc_run_obj_finalizer(RARRAY_AREF(table, 0), count, wbcheck_get_final, (void *)table);
+ FL_UNSET(obj, FL_FINALIZE);
+ }
+ info->finalizers = 0;
+}
+
+static int
+wbcheck_shutdown_call_finalizer_callback(VALUE obj, rb_wbcheck_object_info_t *info, void *data)
+{
+ wbcheck_run_finalizers_for_object(obj, info);
+ return ST_CONTINUE; /* Keep iterating through all objects */
+}
+
+static int
+wbcheck_verify_all_references_callback(VALUE obj, rb_wbcheck_object_info_t *info, void *data)
+{
+ void *objspace_ptr = data;
+ wbcheck_verify_object_references(objspace_ptr, obj);
+ return ST_CONTINUE;
+}
+
+static int
+wbcheck_update_all_snapshots_callback(VALUE obj, rb_wbcheck_object_info_t *info, void *data)
+{
+ void *objspace_ptr = data;
+
+ // For wb_protected objects, do full verification if they have a snapshot
+ if (info->wb_protected && info->state != WBCHECK_STATE_CLEAR) {
+ wbcheck_verify_object_references(objspace_ptr, obj);
+ } else {
+ // For CLEAR objects (wb_protected or not) and non-wb_protected objects, just take a new snapshot
+ wbcheck_object_list_t *current_refs = wbcheck_collect_references_from_object(obj, info);
+ wbcheck_object_list_free(info->gc_mark_snapshot);
+ info->gc_mark_snapshot = current_refs;
+ info->state = WBCHECK_STATE_MARKED;
+ }
+
+ return ST_CONTINUE;
+}
+
+static int
+wbcheck_shutdown_finalizer_callback(VALUE obj, rb_wbcheck_object_info_t *info, void *data)
+{
+ void *objspace_ptr = data;
+
+ if (rb_gc_shutdown_call_finalizer_p(obj)) {
+ WBCHECK_DEBUG("wbcheck: finalizing object during shutdown: %p\n", (void *)obj);
+ rb_gc_obj_free_vm_weak_references(obj);
+ if (rb_gc_obj_free(objspace_ptr, obj)) {
+ RBASIC(obj)->flags = 0;
+ }
+ }
+
+ return ST_CONTINUE;
+}
+
+
+void
+rb_gc_impl_shutdown_call_finalizer(void *objspace_ptr)
+{
+ rb_wbcheck_objspace_t *objspace = objspace_ptr;
+
+ // Call all finalizers for all objects using our shared iteration helper
+ wbcheck_foreach_object(objspace, wbcheck_shutdown_call_finalizer_callback, NULL);
+
+ // After all finalizers have been called, verify all object references
+ unsigned int verify_lev = RB_GC_VM_LOCK();
+ WBCHECK_DEBUG("wbcheck: verifying references for all objects after finalizers\n");
+ wbcheck_foreach_object(objspace, wbcheck_verify_all_references_callback, objspace_ptr);
+ WBCHECK_DEBUG("wbcheck: finished verifying all object references\n");
+ RB_GC_VM_UNLOCK(verify_lev);
+
+ // Print summary and exit with error code if violations were found
+ if (objspace->missed_write_barrier_parents > 0 || objspace->missed_write_barrier_children > 0) {
+ fprintf(stderr, "WBCHECK SUMMARY: Found %zu objects with missed write barriers (%zu total violations)\n",
+ objspace->missed_write_barrier_parents, objspace->missed_write_barrier_children);
+
+
+ exit(1); // Exit with error code to indicate violations were found
+ } else {
+ WBCHECK_DEBUG("wbcheck: no write barrier violations detected\n");
+ }
+
+ // Call rb_gc_obj_free on objects that need shutdown finalization (File, Data with dfree, etc.)
+ unsigned int lev = RB_GC_VM_LOCK();
+ WBCHECK_DEBUG("wbcheck: calling rb_gc_obj_free on objects that need shutdown finalization\n");
+ wbcheck_foreach_object(objspace, wbcheck_shutdown_finalizer_callback, objspace_ptr);
+ WBCHECK_DEBUG("wbcheck: finished calling rb_gc_obj_free\n");
+
+ // Run any pending finalizer jobs (dfree functions)
+ WBCHECK_DEBUG("wbcheck: running pending finalizer jobs\n");
+ gc_run_finalizers(objspace);
+ WBCHECK_DEBUG("wbcheck: finished running finalizer jobs\n");
+ RB_GC_VM_UNLOCK(lev);
+}
+
+// Forking
+void
+rb_gc_impl_before_fork(void *objspace_ptr)
+{
+ // Stub implementation
+}
+
+void
+rb_gc_impl_after_fork(void *objspace_ptr, rb_pid_t pid)
+{
+ // Stub implementation
+}
+
+// Statistics
+void
+rb_gc_impl_set_measure_total_time(void *objspace_ptr, VALUE flag)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ objspace->measure_total_time = RTEST(flag);
+}
+
+bool
+rb_gc_impl_get_measure_total_time(void *objspace_ptr)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ return objspace->measure_total_time;
+}
+
+unsigned long long
+rb_gc_impl_get_total_time(void *objspace_ptr)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ return objspace->measure_total_time ? objspace->simulated_gc_count : 0;
+}
+
+size_t
+rb_gc_impl_gc_count(void *objspace_ptr)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ if (objspace) {
+ return objspace->simulated_gc_count;
+ }
+ return 0;
+}
+
+VALUE
+rb_gc_impl_latest_gc_info(void *objspace_ptr, VALUE key)
+{
+ // Stub implementation
+ return Qnil;
+}
+
+VALUE
+rb_gc_impl_stat(void *objspace_ptr, VALUE hash_or_sym)
+{
+ rb_wbcheck_objspace_t *objspace = (rb_wbcheck_objspace_t *)objspace_ptr;
+ GC_ASSERT(objspace);
+
+ VALUE hash = Qnil, key = Qnil;
+
+ if (RB_TYPE_P(hash_or_sym, T_HASH)) {
+ hash = hash_or_sym;
+ }
+ else if (SYMBOL_P(hash_or_sym)) {
+ key = hash_or_sym;
+ }
+ else {
+ rb_bug("non-hash or symbol given");
+ }
+
+#define SET(name, attr) \
+ if (key == ID2SYM(rb_intern(#name))) \
+ return SIZET2NUM(attr); \
+ else if (hash != Qnil) \
+ rb_hash_aset(hash, ID2SYM(rb_intern(#name)), SIZET2NUM(attr));
+
+ /* Pretend each GC takes 1ms; :time is reported in milliseconds. */
+ SET(count, objspace->simulated_gc_count);
+ SET(time, objspace->measure_total_time ? objspace->simulated_gc_count : 0);
+ SET(tracked_objects, st_table_size(objspace->object_table));
+#undef SET
+
+ if (!NIL_P(key)) {
+ rb_raise(rb_eArgError, "unknown key: %"PRIsVALUE, rb_sym2str(key));
+ }
+
+ rb_hash_aset(hash, ID2SYM(rb_intern("gc_implementation")), rb_str_new_cstr("wbcheck"));
+
+ return hash;
+}
+
+VALUE
+rb_gc_impl_stat_heap(void *objspace_ptr, VALUE heap_name, VALUE hash_or_sym)
+{
+ if (FIXNUM_P(heap_name) && SYMBOL_P(hash_or_sym)) {
+ int heap_idx = FIX2INT(heap_name);
+ if (heap_idx < 0 || heap_idx >= HEAP_COUNT) {
+ rb_raise(rb_eArgError, "size pool index out of range");
+ }
+
+ if (hash_or_sym == ID2SYM(rb_intern("slot_size"))) {
+ return SIZET2NUM(heap_sizes[heap_idx]);
+ }
+
+ return Qundef;
+ }
+
+ if (RB_TYPE_P(hash_or_sym, T_HASH)) {
+ return hash_or_sym;
+ }
+
+ return Qundef;
+}
+
+const char *
+rb_gc_impl_active_gc_name(void)
+{
+ // Stub implementation
+ return "wbcheck";
+}
+
+// Miscellaneous
+#define WBCHECK_OBJECT_METADATA_ENTRY_COUNT 2
+static struct rb_gc_object_metadata_entry object_metadata_entries[WBCHECK_OBJECT_METADATA_ENTRY_COUNT + 1];
+
+struct rb_gc_object_metadata_entry *
+rb_gc_impl_object_metadata(void *objspace_ptr, VALUE obj)
+{
+ static ID ID_object_id, ID_shareable;
+
+ if (!ID_object_id) {
+ ID_object_id = rb_intern("object_id");
+ ID_shareable = rb_intern("shareable");
+ }
+
+ size_t n = 0;
+
+#define SET_ENTRY(na, v) do { \
+ GC_ASSERT(n < WBCHECK_OBJECT_METADATA_ENTRY_COUNT); \
+ object_metadata_entries[n].name = ID_##na; \
+ object_metadata_entries[n].val = v; \
+ n++; \
+} while (0)
+
+ if (rb_obj_id_p(obj)) SET_ENTRY(object_id, rb_obj_id(obj));
+ if (FL_TEST(obj, FL_SHAREABLE)) SET_ENTRY(shareable, Qtrue);
+#undef SET_ENTRY
+
+ object_metadata_entries[n].name = 0;
+ object_metadata_entries[n].val = 0;
+
+ return object_metadata_entries;
+}
+
+bool
+rb_gc_impl_pointer_to_heap_p(void *objspace_ptr, const void *ptr)
+{
+ GC_ASSERT(wbcheck_global_objspace);
+
+ unsigned int lev = RB_GC_VM_LOCK();
+
+ // Check if this pointer exists in our object tracking table
+ st_data_t value;
+ bool result = st_lookup(wbcheck_global_objspace->object_table, (st_data_t)ptr, &value);
+
+ RB_GC_VM_UNLOCK(lev);
+ return result;
+}
+
+bool
+rb_gc_impl_garbage_object_p(void *objspace_ptr, VALUE obj)
+{
+ unsigned int lev = RB_GC_VM_LOCK();
+
+ // Check if this pointer exists in our object tracking table
+ st_data_t value;
+ bool result = st_lookup(wbcheck_global_objspace->object_table, (st_data_t)obj, &value);
+
+ RB_GC_VM_UNLOCK(lev);
+ return !result;
+}
+
+void
+rb_gc_impl_set_event_hook(void *objspace_ptr, const rb_event_flag_t event)
+{
+ // Stub implementation
+}
+
+void
+rb_gc_impl_copy_attributes(void *objspace_ptr, VALUE dest, VALUE obj)
+{
+ rb_wbcheck_object_info_t *src_info = wbcheck_get_object_info(obj);
+
+ if (!src_info->wb_protected) {
+ rb_gc_impl_writebarrier_unprotect(objspace_ptr, dest);
+ }
+ rb_gc_impl_copy_finalizer(objspace_ptr, dest, obj);
+}
+