diff options
Diffstat (limited to 'cont.c')
| -rw-r--r-- | cont.c | 3827 |
1 files changed, 3392 insertions, 435 deletions
@@ -1,6 +1,6 @@ /********************************************************************** - cont.c - + cont.c - $Author$ created at: Thu May 23 09:03:43 2007 @@ -9,146 +9,1522 @@ **********************************************************************/ -#include "ruby/ruby.h" -#include "vm_core.h" -#include "gc.h" +#include "ruby/internal/config.h" + +#ifndef _WIN32 +#include <unistd.h> +#include <sys/mman.h> +#endif + +// On Solaris, madvise() is NOT declared for SUS (XPG4v2) or later, +// but MADV_* macros are defined when __EXTENSIONS__ is defined. +#ifdef NEED_MADVICE_PROTOTYPE_USING_CADDR_T +#include <sys/types.h> +extern int madvise(caddr_t, size_t, int); +#endif + +#include COROUTINE_H + #include "eval_intern.h" +#include "internal.h" +#include "internal/cont.h" +#include "internal/thread.h" +#include "internal/error.h" +#include "internal/eval.h" +#include "internal/gc.h" +#include "internal/proc.h" +#include "internal/sanitizers.h" +#include "internal/warnings.h" +#include "ruby/fiber/scheduler.h" +#include "yjit.h" +#include "vm_core.h" +#include "vm_sync.h" +#include "id_table.h" +#include "ractor_core.h" +#include "zjit.h" + +enum { + DEBUG = 0, + DEBUG_EXPAND = 0, + DEBUG_ACQUIRE = 0, +}; + +#define RB_PAGE_SIZE (pagesize) +#define RB_PAGE_MASK (~(RB_PAGE_SIZE - 1)) +static long pagesize; + +static const rb_data_type_t rb_cont_data_type; +static const rb_data_type_t rb_fiber_data_type; +static VALUE rb_cContinuation; +static VALUE rb_cFiber; +static VALUE rb_eFiberError; +#ifdef RB_EXPERIMENTAL_FIBER_POOL +static VALUE rb_cFiberPool; +#endif + +#define CAPTURE_JUST_VALID_VM_STACK 1 + +// Defined in `coroutine/$arch/Context.h`: +#ifdef COROUTINE_LIMITED_ADDRESS_SPACE +#define FIBER_POOL_ALLOCATION_FREE +#define FIBER_POOL_MINIMUM_COUNT 8 +#define FIBER_POOL_MAXIMUM_ALLOCATIONS 32 +#else +#define FIBER_POOL_MINIMUM_COUNT 32 +#define FIBER_POOL_MAXIMUM_ALLOCATIONS 1024 +#endif +#ifdef RB_EXPERIMENTAL_FIBER_POOL +#define FIBER_POOL_ALLOCATION_FREE +#endif enum context_type { CONTINUATION_CONTEXT = 0, - FIBER_CONTEXT = 1, - ROOT_FIBER_CONTEXT = 2, + FIBER_CONTEXT = 1 }; +struct cont_saved_vm_stack { + VALUE *ptr; + size_t size; +#ifdef CAPTURE_JUST_VALID_VM_STACK + size_t slen; /* length of stack (head of ec->vm_stack) */ + size_t clen; /* length of control frames (tail of ec->vm_stack) */ +#endif +}; + +struct fiber_pool; + +// Represents a single stack. +struct fiber_pool_stack { + // A pointer to the memory allocation (lowest address) for the stack. + void * base; + + // The current stack pointer, taking into account the direction of the stack. + void * current; + + // The size of the stack excluding any guard pages. + size_t size; + + // The available stack capacity w.r.t. the current stack offset. + size_t available; + + // The pool this stack should be allocated from. + struct fiber_pool * pool; + + // If the stack is allocated, the allocation it came from. + struct fiber_pool_allocation * allocation; +}; + +// A linked list of vacant (unused) stacks. +// This structure is stored in the first page of a stack if it is not in use. +// @sa fiber_pool_vacancy_pointer +struct fiber_pool_vacancy { + // Details about the vacant stack: + struct fiber_pool_stack stack; + + // The vacancy linked list. +#ifdef FIBER_POOL_ALLOCATION_FREE + struct fiber_pool_vacancy * previous; +#endif + struct fiber_pool_vacancy * next; +}; + +// Manages singly linked list of mapped regions of memory which contains 1 more more stack: +// +// base = +-------------------------------+-----------------------+ + +// |VM Stack |VM Stack | | | +// | | | | | +// | | | | | +// +-------------------------------+ | | +// |Machine Stack |Machine Stack | | | +// | | | | | +// | | | | | +// | | | . . . . | | size +// | | | | | +// | | | | | +// | | | | | +// | | | | | +// | | | | | +// +-------------------------------+ | | +// |Guard Page |Guard Page | | | +// +-------------------------------+-----------------------+ v +// +// +-------------------------------------------------------> +// +// count +// +struct fiber_pool_allocation { + // A pointer to the memory mapped region. + void * base; + + // The size of the individual stacks. + size_t size; + + // The stride of individual stacks (including any guard pages or other accounting details). + size_t stride; + + // The number of stacks that were allocated. + size_t count; + +#ifdef FIBER_POOL_ALLOCATION_FREE + // The number of stacks used in this allocation. + size_t used; +#endif + + struct fiber_pool * pool; + + // The allocation linked list. +#ifdef FIBER_POOL_ALLOCATION_FREE + struct fiber_pool_allocation * previous; +#endif + struct fiber_pool_allocation * next; +}; + +// A fiber pool manages vacant stacks to reduce the overhead of creating fibers. +struct fiber_pool { + // A singly-linked list of allocations which contain 1 or more stacks each. + struct fiber_pool_allocation * allocations; + + // Free list that provides O(1) stack "allocation". + struct fiber_pool_vacancy * vacancies; + + // The size of the stack allocations (excluding any guard page). + size_t size; + + // The total number of stacks that have been allocated in this pool. + size_t count; + + // The initial number of stacks to allocate. + size_t minimum_count; + + // If positive, total stacks in this pool cannot exceed this (shared pool only: + // set via RUBY_SHARED_FIBER_POOL_MAXIMUM_COUNT). Expansion fails with errno EAGAIN. + size_t maximum_count; + + // Whether to madvise(free) the stack or not. + // If this value is set to 1, the stack will be madvise(free)ed + // (or equivalent), where possible, when it is returned to the pool. + int free_stacks; + + // The number of stacks that have been used in this pool. + size_t used; + + // The amount to allocate for the vm_stack. + size_t vm_stack_size; +}; + +// Continuation contexts used by JITs +struct rb_jit_cont { + rb_execution_context_t *ec; // continuation ec + struct rb_jit_cont *prev, *next; // used to form lists +}; + +// Doubly linked list for enumerating all on-stack ISEQs. +static struct rb_jit_cont *first_jit_cont; + typedef struct rb_context_struct { + enum context_type type; + int argc; + int kw_splat; VALUE self; VALUE value; - VALUE *vm_stack; - VALUE *machine_stack; - VALUE *machine_stack_src; -#ifdef __ia64 - VALUE *machine_register_stack; - VALUE *machine_register_stack_src; - int machine_register_stack_size; -#endif - rb_thread_t saved_thread; + + struct cont_saved_vm_stack saved_vm_stack; + + struct { + VALUE *stack; + VALUE *stack_src; + size_t stack_size; + } machine; + rb_execution_context_t saved_ec; rb_jmpbuf_t jmpbuf; - int machine_stack_size; - VALUE prev; - int alive; - enum context_type type; + struct rb_jit_cont *jit_cont; // Continuation contexts for JITs } rb_context_t; -static VALUE rb_cContinuation; -static VALUE rb_cFiber; -static VALUE rb_eFiberError; +/* + * Fiber status: + * [Fiber.new] ------> FIBER_CREATED ----> [Fiber#kill] --> | + * | [Fiber#resume] | + * v | + * +--> FIBER_RESUMED ----> [return] ------> | + * [Fiber#resume] | | [Fiber.yield/transfer] | + * [Fiber#transfer] | v | + * +--- FIBER_SUSPENDED --> [Fiber#kill] --> | + * | + * | + * FIBER_TERMINATED <-------------------+ + */ +enum fiber_status { + FIBER_CREATED, + FIBER_RESUMED, + FIBER_SUSPENDED, + FIBER_TERMINATED +}; + +#define FIBER_CREATED_P(fiber) ((fiber)->status == FIBER_CREATED) +#define FIBER_RESUMED_P(fiber) ((fiber)->status == FIBER_RESUMED) +#define FIBER_SUSPENDED_P(fiber) ((fiber)->status == FIBER_SUSPENDED) +#define FIBER_TERMINATED_P(fiber) ((fiber)->status == FIBER_TERMINATED) +#define FIBER_RUNNABLE_P(fiber) (FIBER_CREATED_P(fiber) || FIBER_SUSPENDED_P(fiber)) + +struct rb_fiber_struct { + rb_context_t cont; + VALUE first_proc; + struct rb_fiber_struct *prev; + struct rb_fiber_struct *resuming_fiber; + + BITFIELD(enum fiber_status, status, 2); + /* Whether the fiber is allowed to implicitly yield. */ + unsigned int yielding : 1; + unsigned int blocking : 1; + + unsigned int killed : 1; + + struct coroutine_context context; + struct fiber_pool_stack stack; +}; + +static struct fiber_pool shared_fiber_pool = {NULL, NULL, 0, 0, 0, 0}; + +void +rb_free_shared_fiber_pool(void) +{ + struct fiber_pool_allocation *allocations = shared_fiber_pool.allocations; + while (allocations) { + struct fiber_pool_allocation *next = allocations->next; + SIZED_FREE(allocations); + allocations = next; + } +} + +static ID fiber_initialize_keywords[3] = {0}; + +/* + * FreeBSD require a first (i.e. addr) argument of mmap(2) is not NULL + * if MAP_STACK is passed. + * https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=158755 + */ +#if defined(MAP_STACK) && !defined(__FreeBSD__) && !defined(__FreeBSD_kernel__) +#define FIBER_STACK_FLAGS (MAP_PRIVATE | MAP_ANON | MAP_STACK) +#else +#define FIBER_STACK_FLAGS (MAP_PRIVATE | MAP_ANON) +#endif + +#define ERRNOMSG strerror(errno) + +// Locates the stack vacancy details for the given stack. +inline static struct fiber_pool_vacancy * +fiber_pool_vacancy_pointer(void * base, size_t size) +{ + STACK_GROW_DIR_DETECTION; + + return (struct fiber_pool_vacancy *)( + (char*)base + STACK_DIR_UPPER(0, size - RB_PAGE_SIZE) + ); +} + +#if defined(COROUTINE_SANITIZE_ADDRESS) +// Compute the base pointer for a vacant stack, for the area which can be poisoned. +inline static void * +fiber_pool_stack_poison_base(struct fiber_pool_stack * stack) +{ + STACK_GROW_DIR_DETECTION; + + return (char*)stack->base + STACK_DIR_UPPER(RB_PAGE_SIZE, 0); +} + +// Compute the size of the vacant stack, for the area that can be poisoned. +inline static size_t +fiber_pool_stack_poison_size(struct fiber_pool_stack * stack) +{ + return stack->size - RB_PAGE_SIZE; +} +#endif + +// Reset the current stack pointer and available size of the given stack. +inline static void +fiber_pool_stack_reset(struct fiber_pool_stack * stack) +{ + STACK_GROW_DIR_DETECTION; + + stack->current = (char*)stack->base + STACK_DIR_UPPER(0, stack->size); + stack->available = stack->size; +} + +// A pointer to the base of the current unused portion of the stack. +inline static void * +fiber_pool_stack_base(struct fiber_pool_stack * stack) +{ + STACK_GROW_DIR_DETECTION; + + VM_ASSERT(stack->current); + + return STACK_DIR_UPPER(stack->current, (char*)stack->current - stack->available); +} + +// Allocate some memory from the stack. Used to allocate vm_stack inline with machine stack. +// @sa fiber_initialize_coroutine +inline static void * +fiber_pool_stack_alloca(struct fiber_pool_stack * stack, size_t offset) +{ + STACK_GROW_DIR_DETECTION; + + if (DEBUG) fprintf(stderr, "fiber_pool_stack_alloca(%p): %"PRIuSIZE"/%"PRIuSIZE"\n", (void*)stack, offset, stack->available); + VM_ASSERT(stack->available >= offset); + + // The pointer to the memory being allocated: + void * pointer = STACK_DIR_UPPER(stack->current, (char*)stack->current - offset); + + // Move the stack pointer: + stack->current = STACK_DIR_UPPER((char*)stack->current + offset, (char*)stack->current - offset); + stack->available -= offset; + + return pointer; +} + +// Reset the current stack pointer and available size of the given stack. +inline static void +fiber_pool_vacancy_reset(struct fiber_pool_vacancy * vacancy) +{ + fiber_pool_stack_reset(&vacancy->stack); + + // Consume one page of the stack because it's used for the vacancy list: + fiber_pool_stack_alloca(&vacancy->stack, RB_PAGE_SIZE); +} + +inline static struct fiber_pool_vacancy * +fiber_pool_vacancy_push(struct fiber_pool_vacancy * vacancy, struct fiber_pool_vacancy * head) +{ + vacancy->next = head; + +#ifdef FIBER_POOL_ALLOCATION_FREE + if (head) { + head->previous = vacancy; + vacancy->previous = NULL; + } +#endif + + return vacancy; +} + +#ifdef FIBER_POOL_ALLOCATION_FREE +static void +fiber_pool_vacancy_remove(struct fiber_pool_vacancy * vacancy) +{ + if (vacancy->next) { + vacancy->next->previous = vacancy->previous; + } + + if (vacancy->previous) { + vacancy->previous->next = vacancy->next; + } + else { + // It's the head of the list: + vacancy->stack.pool->vacancies = vacancy->next; + } +} + +inline static struct fiber_pool_vacancy * +fiber_pool_vacancy_pop(struct fiber_pool * pool) +{ + struct fiber_pool_vacancy * vacancy = pool->vacancies; + + if (vacancy) { + fiber_pool_vacancy_remove(vacancy); + } + + return vacancy; +} +#else +inline static struct fiber_pool_vacancy * +fiber_pool_vacancy_pop(struct fiber_pool * pool) +{ + struct fiber_pool_vacancy * vacancy = pool->vacancies; + + if (vacancy) { + pool->vacancies = vacancy->next; + } + + return vacancy; +} +#endif + +// Initialize the vacant stack. The [base, size] allocation should not include the guard page. +// @param base The pointer to the lowest address of the allocated memory. +// @param size The size of the allocated memory. +inline static struct fiber_pool_vacancy * +fiber_pool_vacancy_initialize(struct fiber_pool * fiber_pool, struct fiber_pool_vacancy * vacancies, void * base, size_t size) +{ + struct fiber_pool_vacancy * vacancy = fiber_pool_vacancy_pointer(base, size); + + vacancy->stack.base = base; + vacancy->stack.size = size; + + fiber_pool_vacancy_reset(vacancy); + + vacancy->stack.pool = fiber_pool; -#define GetContPtr(obj, ptr) \ - Data_Get_Struct(obj, rb_context_t, ptr) + return fiber_pool_vacancy_push(vacancy, vacancies); +} + +// Allocate a maximum of count stacks, size given by stride. +// @param count the number of stacks to allocate / were allocated. +// @param stride the size of the individual stacks. +// @return [void *] the allocated memory or NULL if allocation failed. +inline static void * +fiber_pool_allocate_memory(size_t * count, size_t stride) +{ + // We use a divide-by-2 strategy to try and allocate memory. We are trying + // to allocate `count` stacks. In normal situation, this won't fail. But + // if we ran out of address space, or we are allocating more memory than + // the system would allow (e.g. overcommit * physical memory + swap), we + // divide count by two and try again. This condition should only be + // encountered in edge cases, but we handle it here gracefully. + while (*count) { +#if defined(_WIN32) + void * base = VirtualAlloc(0, (*count)*stride, MEM_COMMIT, PAGE_READWRITE); + + if (!base) { + errno = rb_w32_map_errno(GetLastError()); + *count = (*count) >> 1; + } + else { + return base; + } +#else + errno = 0; + size_t mmap_size = (*count)*stride; + void * base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, FIBER_STACK_FLAGS, -1, 0); + + if (base == MAP_FAILED) { + // If the allocation fails, count = count / 2, and try again. + *count = (*count) >> 1; + } + else { + ruby_annotate_mmap(base, mmap_size, "Ruby:fiber_pool_allocate_memory"); +#if defined(MADV_FREE_REUSE) + // On Mac MADV_FREE_REUSE is necessary for the task_info api + // to keep the accounting accurate as possible when a page is marked as reusable + // it can possibly not occurring at first call thus re-iterating if necessary. + while (madvise(base, mmap_size, MADV_FREE_REUSE) == -1 && errno == EAGAIN); +#endif + return base; + } +#endif + } + + return NULL; +} + +// Given an existing fiber pool, expand it by the specified number of stacks. +// +// @param count the maximum number of stacks to allocate. +// @return the new allocation on success, or NULL on failure with errno set. +// @raise NoMemoryError if the struct or memory allocation fails. +// +// Call from fiber_pool_stack_acquire_expand with VM lock held, or from +// fiber_pool_initialize before the pool is shared across threads. +// @sa fiber_pool_allocation_free +static struct fiber_pool_allocation * +fiber_pool_expand(struct fiber_pool * fiber_pool, size_t count) +{ + if (count == 0) { + errno = EAGAIN; + return NULL; + } + + STACK_GROW_DIR_DETECTION; + + size_t size = fiber_pool->size; + size_t stride = size + RB_PAGE_SIZE; + + // If the maximum number of stacks is set, and we have reached it, return NULL. + if (fiber_pool->maximum_count > 0) { + if (fiber_pool->count >= fiber_pool->maximum_count) { + errno = EAGAIN; + return NULL; + } + size_t remaining = fiber_pool->maximum_count - fiber_pool->count; + if (count > remaining) { + count = remaining; + } + } + + // Allocate metadata before mmap: ruby_xmalloc (RB_ALLOC) raises on failure and + // must not run after base is mapped, or the region would leak. + struct fiber_pool_allocation * allocation = RB_ALLOC(struct fiber_pool_allocation); + + // Allocate the memory required for the stacks: + void * base = fiber_pool_allocate_memory(&count, stride); + + if (base == NULL) { + if (!errno) errno = ENOMEM; + ruby_xfree(allocation); + return NULL; + } + + struct fiber_pool_vacancy * vacancies = fiber_pool->vacancies; -NOINLINE(static VALUE cont_capture(volatile int *stat)); + // Initialize fiber pool allocation: + allocation->base = base; + allocation->size = size; + allocation->stride = stride; + allocation->count = count; +#ifdef FIBER_POOL_ALLOCATION_FREE + allocation->used = 0; +#endif + allocation->pool = fiber_pool; + + if (DEBUG_EXPAND) { + fprintf(stderr, "fiber_pool_expand(%"PRIuSIZE"): %p, %"PRIuSIZE"/%"PRIuSIZE" x [%"PRIuSIZE":%"PRIuSIZE"]\n", + count, (void*)fiber_pool, fiber_pool->used, fiber_pool->count, size, fiber_pool->vm_stack_size); + } + + // Iterate over all stacks, initializing the vacancy list: + for (size_t i = 0; i < count; i += 1) { + void * base = (char*)allocation->base + (stride * i); + void * page = (char*)base + STACK_DIR_UPPER(size, 0); +#if defined(_WIN32) + DWORD old_protect; + + if (!VirtualProtect(page, RB_PAGE_SIZE, PAGE_READWRITE | PAGE_GUARD, &old_protect)) { + int error = rb_w32_map_errno(GetLastError()); + VirtualFree(allocation->base, 0, MEM_RELEASE); + ruby_xfree(allocation); + errno = error; + return NULL; + } +#elif defined(__wasi__) + // wasi-libc's mprotect emulation doesn't support PROT_NONE. + (void)page; +#else + if (mprotect(page, RB_PAGE_SIZE, PROT_NONE) < 0) { + int error = errno; + if (!error) error = ENOMEM; + munmap(allocation->base, count*stride); + ruby_xfree(allocation); + errno = error; + return NULL; + } +#endif + + vacancies = fiber_pool_vacancy_initialize( + fiber_pool, vacancies, + (char*)base + STACK_DIR_UPPER(0, RB_PAGE_SIZE), + size + ); + +#ifdef FIBER_POOL_ALLOCATION_FREE + vacancies->stack.allocation = allocation; +#endif + } -void rb_thread_mark(rb_thread_t *th); + // Insert the allocation into the head of the pool: + allocation->next = fiber_pool->allocations; + +#ifdef FIBER_POOL_ALLOCATION_FREE + if (allocation->next) { + allocation->next->previous = allocation; + } + + allocation->previous = NULL; +#endif + + fiber_pool->allocations = allocation; + fiber_pool->vacancies = vacancies; + fiber_pool->count += count; + + return allocation; +} + +// Initialize the specified fiber pool with the given number of stacks. +// @param vm_stack_size The size of the vm stack to allocate. +static void +fiber_pool_initialize(struct fiber_pool * fiber_pool, size_t size, size_t minimum_count, size_t maximum_count, size_t vm_stack_size) +{ + VM_ASSERT(vm_stack_size < size); + + fiber_pool->allocations = NULL; + fiber_pool->vacancies = NULL; + fiber_pool->size = ((size / RB_PAGE_SIZE) + 1) * RB_PAGE_SIZE; + fiber_pool->count = 0; + fiber_pool->minimum_count = minimum_count; + fiber_pool->maximum_count = maximum_count; + fiber_pool->free_stacks = 1; + fiber_pool->used = 0; + fiber_pool->vm_stack_size = vm_stack_size; + + if (fiber_pool->minimum_count > 0) { + if (RB_UNLIKELY(!fiber_pool_expand(fiber_pool, fiber_pool->minimum_count))) { + rb_raise(rb_eFiberError, "can't allocate initial fiber stacks (%"PRIuSIZE" x %"PRIuSIZE" bytes): %s", fiber_pool->minimum_count, fiber_pool->size, strerror(errno)); + } + } +} + +#ifdef FIBER_POOL_ALLOCATION_FREE +// Free the list of fiber pool allocations. +static void +fiber_pool_allocation_free(struct fiber_pool_allocation * allocation) +{ + STACK_GROW_DIR_DETECTION; + + VM_ASSERT(allocation->used == 0); + + if (DEBUG) fprintf(stderr, "fiber_pool_allocation_free: %p base=%p count=%"PRIuSIZE"\n", (void*)allocation, allocation->base, allocation->count); + + size_t i; + for (i = 0; i < allocation->count; i += 1) { + void * base = (char*)allocation->base + (allocation->stride * i) + STACK_DIR_UPPER(0, RB_PAGE_SIZE); + + struct fiber_pool_vacancy * vacancy = fiber_pool_vacancy_pointer(base, allocation->size); + + // Pop the vacant stack off the free list: + fiber_pool_vacancy_remove(vacancy); + } + +#ifdef _WIN32 + VirtualFree(allocation->base, 0, MEM_RELEASE); +#else + munmap(allocation->base, allocation->stride * allocation->count); +#endif + + if (allocation->previous) { + allocation->previous->next = allocation->next; + } + else { + // We are the head of the list, so update the pool: + allocation->pool->allocations = allocation->next; + } + + if (allocation->next) { + allocation->next->previous = allocation->previous; + } + + allocation->pool->count -= allocation->count; + + SIZED_FREE(allocation); +} +#endif + +// Number of stacks to request when expanding the pool (clamped to min/max). +static size_t +fiber_pool_stack_expand_count(const struct fiber_pool *pool) +{ + const size_t maximum_allocations = FIBER_POOL_MAXIMUM_ALLOCATIONS; + const size_t minimum_count = FIBER_POOL_MINIMUM_COUNT; + + // We are going try and double the number of stacks in the pool: + size_t count = pool->count; + if (count > maximum_allocations) count = maximum_allocations; + if (count < minimum_count) count = minimum_count; + + // If we have a maximum count, we need to clamp the number of stacks to the maximum: + if (pool->maximum_count > 0) { + if (pool->count >= pool->maximum_count) { + // No expansion is possible: + return 0; + } + + // Otherwise, compute the number of stacks we can allocate to bring us to the maximum: + size_t remaining = pool->maximum_count - pool->count; + if (count > remaining) { + count = remaining; + } + } + + return count; +} + +// When the vacancy list is empty, grow the pool (and run GC only if mmap fails). Caller holds the VM lock. +// Returns NULL if expansion failed after GC + retry; errno is set. Otherwise returns a vacancy. +static struct fiber_pool_vacancy * +fiber_pool_stack_acquire_expand(struct fiber_pool *fiber_pool) +{ + size_t count = fiber_pool_stack_expand_count(fiber_pool); + + if (DEBUG_ACQUIRE) fprintf(stderr, "fiber_pool_stack_acquire: expanding fiber pool by %"PRIuSIZE" stacks\n", count); + + struct fiber_pool_vacancy *vacancy = NULL; + + if (RB_LIKELY(fiber_pool_expand(fiber_pool, count))) { + return fiber_pool_vacancy_pop(fiber_pool); + } + else { + if (DEBUG_ACQUIRE) fprintf(stderr, "fiber_pool_stack_acquire: expand failed (%s), collecting garbage\n", strerror(errno)); + + rb_gc(); + + // After running GC, the vacancy list may have some stacks: + vacancy = fiber_pool_vacancy_pop(fiber_pool); + if (RB_LIKELY(vacancy)) { + return vacancy; + } + + // Recompute count as gc may have freed up some allocations: + count = fiber_pool_stack_expand_count(fiber_pool); + + // Try to expand the fiber pool again: + if (RB_LIKELY(fiber_pool_expand(fiber_pool, count))) { + return fiber_pool_vacancy_pop(fiber_pool); + } + else { + // Okay, we really failed to acquire a stack. Give up and return NULL with errno set: + return NULL; + } + } +} + +// Acquire a stack from the given fiber pool. If none are available, allocate more. +static struct fiber_pool_stack +fiber_pool_stack_acquire(struct fiber_pool * fiber_pool) +{ + struct fiber_pool_vacancy * vacancy; + + unsigned int lev; + RB_VM_LOCK_ENTER_LEV(&lev); + { + // Fast path: try to acquire a stack from the vacancy list: + vacancy = fiber_pool_vacancy_pop(fiber_pool); + + if (DEBUG) fprintf(stderr, "fiber_pool_stack_acquire: %p used=%"PRIuSIZE"\n", (void*)fiber_pool->vacancies, fiber_pool->used); + + // Slow path: If the pool has no vacancies, expand first. Only run GC when expansion fails (e.g. mmap), so we can reclaim stacks from dead fibers before retrying: + if (RB_UNLIKELY(!vacancy)) { + vacancy = fiber_pool_stack_acquire_expand(fiber_pool); + + // If expansion failed, raise an error: + if (RB_UNLIKELY(!vacancy)) { + RB_VM_LOCK_LEAVE_LEV(&lev); + rb_raise(rb_eFiberError, "can't allocate fiber stack: %s", strerror(errno)); + } + } + + VM_ASSERT(vacancy); + VM_ASSERT(vacancy->stack.base); + +#if defined(COROUTINE_SANITIZE_ADDRESS) + __asan_unpoison_memory_region(fiber_pool_stack_poison_base(&vacancy->stack), fiber_pool_stack_poison_size(&vacancy->stack)); +#endif + + // Take the top item from the free list: + fiber_pool->used += 1; + +#ifdef FIBER_POOL_ALLOCATION_FREE + vacancy->stack.allocation->used += 1; +#endif + + fiber_pool_stack_reset(&vacancy->stack); + } + RB_VM_LOCK_LEAVE_LEV(&lev); + + return vacancy->stack; +} + +// We advise the operating system that the stack memory pages are no longer being used. +// This introduce some performance overhead but allows system to relaim memory when there is pressure. +static inline void +fiber_pool_stack_free(struct fiber_pool_stack * stack) +{ + void * base = fiber_pool_stack_base(stack); + size_t size = stack->available; + + // If this is not true, the vacancy information will almost certainly be destroyed: + VM_ASSERT(size <= (stack->size - RB_PAGE_SIZE)); + + int advice = stack->pool->free_stacks >> 1; + + if (DEBUG) fprintf(stderr, "fiber_pool_stack_free: %p+%"PRIuSIZE" [base=%p, size=%"PRIuSIZE"] advice=%d\n", base, size, stack->base, stack->size, advice); + + // The pages being used by the stack can be returned back to the system. + // That doesn't change the page mapping, but it does allow the system to + // reclaim the physical memory. + // Since we no longer care about the data itself, we don't need to page + // out to disk, since that is costly. Not all systems support that, so + // we try our best to select the most efficient implementation. + // In addition, it's actually slightly desirable to not do anything here, + // but that results in higher memory usage. + +#ifdef __wasi__ + // WebAssembly doesn't support madvise, so we just don't do anything. +#elif VM_CHECK_MODE > 0 && defined(MADV_DONTNEED) + if (!advice) advice = MADV_DONTNEED; + // This immediately discards the pages and the memory is reset to zero. + madvise(base, size, advice); +#elif defined(MADV_FREE_REUSABLE) + if (!advice) advice = MADV_FREE_REUSABLE; + // Darwin / macOS / iOS. + // Acknowledge the kernel down to the task info api we make this + // page reusable for future use. + // As for MADV_FREE_REUSABLE below we ensure in the rare occasions the task was not + // completed at the time of the call to re-iterate. + while (madvise(base, size, advice) == -1 && errno == EAGAIN); +#elif defined(MADV_FREE) + if (!advice) advice = MADV_FREE; + // Recent Linux. + madvise(base, size, advice); +#elif defined(MADV_DONTNEED) + if (!advice) advice = MADV_DONTNEED; + // Old Linux. + madvise(base, size, advice); +#elif defined(POSIX_MADV_DONTNEED) + if (!advice) advice = POSIX_MADV_DONTNEED; + // Solaris? + posix_madvise(base, size, advice); +#elif defined(_WIN32) + VirtualAlloc(base, size, MEM_RESET, PAGE_READWRITE); + // Not available in all versions of Windows. + //DiscardVirtualMemory(base, size); +#endif + +#if defined(COROUTINE_SANITIZE_ADDRESS) + __asan_poison_memory_region(fiber_pool_stack_poison_base(stack), fiber_pool_stack_poison_size(stack)); +#endif +} + +// Release and return a stack to the vacancy list. +static void +fiber_pool_stack_release(struct fiber_pool_stack * stack) +{ + struct fiber_pool * pool = stack->pool; + struct fiber_pool_vacancy * vacancy = fiber_pool_vacancy_pointer(stack->base, stack->size); + + if (DEBUG) fprintf(stderr, "fiber_pool_stack_release: %p used=%"PRIuSIZE"\n", stack->base, stack->pool->used); + + // Copy the stack details into the vacancy area: + vacancy->stack = *stack; + // After this point, be careful about updating/using state in stack, since it's copied to the vacancy area. + + // Reset the stack pointers and reserve space for the vacancy data: + fiber_pool_vacancy_reset(vacancy); + + // Push the vacancy into the vancancies list: + pool->vacancies = fiber_pool_vacancy_push(vacancy, pool->vacancies); + pool->used -= 1; + +#ifdef FIBER_POOL_ALLOCATION_FREE + struct fiber_pool_allocation * allocation = stack->allocation; + + allocation->used -= 1; + + // Release address space and/or dirty memory: + if (allocation->used == 0) { + fiber_pool_allocation_free(allocation); + } + else if (stack->pool->free_stacks) { + fiber_pool_stack_free(&vacancy->stack); + } +#else + // This is entirely optional, but clears the dirty flag from the stack + // memory, so it won't get swapped to disk when there is memory pressure: + if (stack->pool->free_stacks) { + fiber_pool_stack_free(&vacancy->stack); + } +#endif +} + +static inline void +ec_switch(rb_thread_t *th, rb_fiber_t *fiber) +{ + rb_execution_context_t *ec = &fiber->cont.saved_ec; +#ifdef RUBY_ASAN_ENABLED + ec->machine.asan_fake_stack_handle = asan_get_thread_fake_stack_handle(); +#endif + rb_ractor_set_current_ec(th->ractor, th->ec = ec); + // ruby_current_execution_context_ptr = th->ec = ec; + + /* + * timer-thread may set trap interrupt on previous th->ec at any time; + * ensure we do not delay (or lose) the trap interrupt handling. + */ + if (th->vm->ractor.main_thread == th && + rb_signal_buff_size() > 0) { + RUBY_VM_SET_TRAP_INTERRUPT(ec); + } + + VM_ASSERT(ec->fiber_ptr->cont.self == 0 || ec->vm_stack != NULL); +} + +static inline void +fiber_restore_thread(rb_thread_t *th, rb_fiber_t *fiber) +{ + ec_switch(th, fiber); + VM_ASSERT(th->ec->fiber_ptr == fiber); +} + +#ifndef COROUTINE_DECL +# define COROUTINE_DECL COROUTINE +#endif +NORETURN(static COROUTINE_DECL fiber_entry(struct coroutine_context * from, struct coroutine_context * to)); +static COROUTINE +fiber_entry(struct coroutine_context * from, struct coroutine_context * to) +{ + rb_fiber_t *fiber = to->argument; + +#if defined(COROUTINE_SANITIZE_ADDRESS) + // Address sanitizer will copy the previous stack base and stack size into + // the "from" fiber. `coroutine_initialize_main` doesn't generally know the + // stack bounds (base + size). Therefore, the main fiber `stack_base` and + // `stack_size` will be NULL/0. It's specifically important in that case to + // get the (base+size) of the previous fiber and save it, so that later when + // we return to the main coroutine, we don't supply (NULL, 0) to + // __sanitizer_start_switch_fiber which royally messes up the internal state + // of ASAN and causes (sometimes) the following message: + // "WARNING: ASan is ignoring requested __asan_handle_no_return" + __sanitizer_finish_switch_fiber(to->fake_stack, (const void**)&from->stack_base, &from->stack_size); +#endif + + rb_thread_t *thread = fiber->cont.saved_ec.thread_ptr; + +#ifdef COROUTINE_PTHREAD_CONTEXT + ruby_thread_set_native(thread); +#endif + + fiber_restore_thread(thread, fiber); + + rb_fiber_start(fiber); + +#ifndef COROUTINE_PTHREAD_CONTEXT + VM_UNREACHABLE(fiber_entry); +#endif +} + +// Initialize a fiber's coroutine's machine stack and vm stack. +static VALUE * +fiber_initialize_coroutine(rb_fiber_t *fiber, size_t * vm_stack_size) +{ + struct fiber_pool * fiber_pool = fiber->stack.pool; + rb_execution_context_t *sec = &fiber->cont.saved_ec; + void * vm_stack = NULL; + + VM_ASSERT(fiber_pool != NULL); + + fiber->stack = fiber_pool_stack_acquire(fiber_pool); + vm_stack = fiber_pool_stack_alloca(&fiber->stack, fiber_pool->vm_stack_size); + *vm_stack_size = fiber_pool->vm_stack_size; + + coroutine_initialize(&fiber->context, fiber_entry, fiber_pool_stack_base(&fiber->stack), fiber->stack.available); + + // The stack for this execution context is the one we allocated: + sec->machine.stack_start = fiber->stack.current; + sec->machine.stack_maxsize = fiber->stack.available; + + fiber->context.argument = (void*)fiber; + + return vm_stack; +} + +// Release the stack from the fiber, it's execution context, and return it to +// the fiber pool. +static void +fiber_stack_release(rb_fiber_t * fiber) +{ + rb_execution_context_t *ec = &fiber->cont.saved_ec; + + if (DEBUG) fprintf(stderr, "fiber_stack_release: %p, stack.base=%p\n", (void*)fiber, fiber->stack.base); + + // Return the stack back to the fiber pool if it wasn't already: + if (fiber->stack.base) { + fiber_pool_stack_release(&fiber->stack); + fiber->stack.base = NULL; + } + + // The stack is no longer associated with this execution context: + rb_ec_clear_vm_stack(ec); +} + +static void +fiber_stack_release_locked(rb_fiber_t *fiber) +{ + if (!ruby_vm_during_cleanup) { + // We can't try to acquire the VM lock here because MMTK calls free in its own native thread which has no ec. + // This assertion will fail on MMTK but we currently don't have CI for debug releases of MMTK, so we can assert for now. + ASSERT_vm_locking_with_barrier(); + } + fiber_stack_release(fiber); +} + +static const char * +fiber_status_name(enum fiber_status s) +{ + switch (s) { + case FIBER_CREATED: return "created"; + case FIBER_RESUMED: return "resumed"; + case FIBER_SUSPENDED: return "suspended"; + case FIBER_TERMINATED: return "terminated"; + } + VM_UNREACHABLE(fiber_status_name); + return NULL; +} + +static void +fiber_verify(const rb_fiber_t *fiber) +{ +#if VM_CHECK_MODE > 0 + VM_ASSERT(fiber->cont.saved_ec.fiber_ptr == fiber); + + switch (fiber->status) { + case FIBER_RESUMED: + if (fiber->cont.saved_ec.thread_ptr->self == 0) { + VM_ASSERT(fiber->cont.saved_ec.vm_stack != NULL); + } + break; + case FIBER_SUSPENDED: + VM_ASSERT(fiber->cont.saved_ec.vm_stack != NULL); + break; + case FIBER_CREATED: + case FIBER_TERMINATED: + /* TODO */ + break; + default: + VM_UNREACHABLE(fiber_verify); + } +#endif +} + +inline static void +fiber_status_set(rb_fiber_t *fiber, enum fiber_status s) +{ + // if (DEBUG) fprintf(stderr, "fiber: %p, status: %s -> %s\n", (void *)fiber, fiber_status_name(fiber->status), fiber_status_name(s)); + VM_ASSERT(!FIBER_TERMINATED_P(fiber)); + VM_ASSERT(fiber->status != s); + fiber_verify(fiber); + fiber->status = s; +} + +static rb_context_t * +cont_ptr(VALUE obj) +{ + rb_context_t *cont; + + TypedData_Get_Struct(obj, rb_context_t, &rb_cont_data_type, cont); + + return cont; +} + +static rb_fiber_t * +fiber_ptr(VALUE obj) +{ + rb_fiber_t *fiber; + + TypedData_Get_Struct(obj, rb_fiber_t, &rb_fiber_data_type, fiber); + if (!fiber) rb_raise(rb_eFiberError, "uninitialized fiber"); + + return fiber; +} + +NOINLINE(static VALUE cont_capture(volatile int *volatile stat)); + +#define THREAD_MUST_BE_RUNNING(th) do { \ + if (!(th)->ec->tag) rb_raise(rb_eThreadError, "not running thread"); \ + } while (0) + +rb_thread_t* +rb_fiber_threadptr(const rb_fiber_t *fiber) +{ + return fiber->cont.saved_ec.thread_ptr; +} + +static VALUE +cont_thread_value(const rb_context_t *cont) +{ + return cont->saved_ec.thread_ptr->self; +} + +static void +cont_compact(void *ptr) +{ + rb_context_t *cont = ptr; + + if (cont->self) { + cont->self = rb_gc_location(cont->self); + } + cont->value = rb_gc_location(cont->value); + rb_execution_context_update(&cont->saved_ec); +} static void cont_mark(void *ptr) { + rb_context_t *cont = ptr; + RUBY_MARK_ENTER("cont"); - if (ptr) { - rb_context_t *cont = ptr; - rb_gc_mark(cont->value); - rb_gc_mark(cont->prev); - rb_thread_mark(&cont->saved_thread); - - if (cont->vm_stack) { - rb_gc_mark_locations(cont->vm_stack, - cont->vm_stack + cont->saved_thread.stack_size); - } - - if (cont->machine_stack) { - rb_gc_mark_locations(cont->machine_stack, - cont->machine_stack + cont->machine_stack_size); - } -#ifdef __ia64 - if (cont->machine_register_stack) { - rb_gc_mark_locations(cont->machine_register_stack, - cont->machine_register_stack + cont->machine_register_stack_size); - } + if (cont->self) { + rb_gc_mark_movable(cont->self); + } + rb_gc_mark_movable(cont->value); + + rb_execution_context_mark(&cont->saved_ec); + rb_gc_mark(cont_thread_value(cont)); + + if (cont->saved_vm_stack.ptr) { +#ifdef CAPTURE_JUST_VALID_VM_STACK + rb_gc_mark_locations(cont->saved_vm_stack.ptr, + cont->saved_vm_stack.ptr + cont->saved_vm_stack.slen + cont->saved_vm_stack.clen); +#else + rb_gc_mark_locations(cont->saved_vm_stack.ptr, + cont->saved_vm_stack.ptr, cont->saved_ec.stack_size); #endif } + + if (cont->machine.stack) { + if (cont->type == CONTINUATION_CONTEXT) { + /* cont */ + rb_gc_mark_locations(cont->machine.stack, + cont->machine.stack + cont->machine.stack_size); + } + else { + /* fiber machine context is marked as part of rb_execution_context_mark, no need to + * do anything here. */ + } + } + RUBY_MARK_LEAVE("cont"); } +#if 0 +static int +fiber_is_root_p(const rb_fiber_t *fiber) +{ + return fiber == fiber->cont.saved_ec.thread_ptr->root_fiber; +} +#endif + +static void jit_cont_free(struct rb_jit_cont *cont); + static void cont_free(void *ptr) { + rb_context_t *cont = ptr; + RUBY_FREE_ENTER("cont"); - if (ptr) { - rb_context_t *cont = ptr; - RUBY_FREE_UNLESS_NULL(cont->saved_thread.stack); - RUBY_FREE_UNLESS_NULL(cont->machine_stack); -#ifdef __ia64 - RUBY_FREE_UNLESS_NULL(cont->machine_register_stack); -#endif - RUBY_FREE_UNLESS_NULL(cont->vm_stack); - if (cont->type == FIBER_CONTEXT) { - st_free_table(cont->saved_thread.local_storage); - } + if (cont->type == CONTINUATION_CONTEXT) { + SIZED_FREE_N(cont->saved_ec.vm_stack, cont->saved_ec.vm_stack_size); + SIZED_FREE_N(cont->machine.stack, cont->machine.stack_size); + } + else { + rb_fiber_t *fiber = (rb_fiber_t*)cont; + coroutine_destroy(&fiber->context); + fiber_stack_release_locked(fiber); + } - ruby_xfree(ptr); + SIZED_FREE_N(cont->saved_vm_stack.ptr, cont->saved_vm_stack.size); + + VM_ASSERT(cont->jit_cont != NULL); + jit_cont_free(cont->jit_cont); + /* free rb_cont_t or rb_fiber_t */ + if (cont->type == CONTINUATION_CONTEXT) { + SIZED_FREE(cont); + } + else { + SIZED_FREE((rb_fiber_t *)cont); } RUBY_FREE_LEAVE("cont"); } +static size_t +cont_memsize(const void *ptr) +{ + const rb_context_t *cont = ptr; + size_t size = 0; + + size = sizeof(*cont); + if (cont->saved_vm_stack.ptr) { +#ifdef CAPTURE_JUST_VALID_VM_STACK + size_t n = (cont->saved_vm_stack.slen + cont->saved_vm_stack.clen); +#else + size_t n = cont->saved_ec.vm_stack_size; +#endif + size += n * sizeof(*cont->saved_vm_stack.ptr); + } + + if (cont->machine.stack) { + size += cont->machine.stack_size * sizeof(*cont->machine.stack); + } + + return size; +} + +void +rb_fiber_update_self(rb_fiber_t *fiber) +{ + if (fiber->cont.self) { + fiber->cont.self = rb_gc_location(fiber->cont.self); + } + else { + rb_execution_context_update(&fiber->cont.saved_ec); + } +} + +void +rb_fiber_mark_self(const rb_fiber_t *fiber) +{ + rb_gc_mark_movable(fiber->cont.self); +} + +static void +fiber_compact(void *ptr) +{ + rb_fiber_t *fiber = ptr; + fiber->first_proc = rb_gc_location(fiber->first_proc); + + if (fiber->prev) rb_fiber_update_self(fiber->prev); + + cont_compact(&fiber->cont); + fiber_verify(fiber); +} + +static void +fiber_mark(void *ptr) +{ + rb_fiber_t *fiber = ptr; + RUBY_MARK_ENTER("cont"); + fiber_verify(fiber); + rb_gc_mark_movable(fiber->first_proc); + if (fiber->prev) rb_fiber_mark_self(fiber->prev); + cont_mark(&fiber->cont); + RUBY_MARK_LEAVE("cont"); +} + +static void +fiber_free(void *ptr) +{ + rb_fiber_t *fiber = ptr; + RUBY_FREE_ENTER("fiber"); + + if (DEBUG) fprintf(stderr, "fiber_free: %p[%p]\n", (void *)fiber, fiber->stack.base); + + if (fiber->cont.saved_ec.local_storage) { + rb_id_table_free(fiber->cont.saved_ec.local_storage); + } + + cont_free(&fiber->cont); + RUBY_FREE_LEAVE("fiber"); +} + +static size_t +fiber_memsize(const void *ptr) +{ + const rb_fiber_t *fiber = ptr; + size_t size = sizeof(*fiber); + const rb_execution_context_t *saved_ec = &fiber->cont.saved_ec; + const rb_thread_t *th = rb_ec_thread_ptr(saved_ec); + + /* + * vm.c::thread_memsize already counts th->ec->local_storage + */ + if (saved_ec->local_storage && fiber != th->root_fiber) { + size += rb_id_table_memsize(saved_ec->local_storage); + size += rb_obj_memsize_of(saved_ec->storage); + } + + size += cont_memsize(&fiber->cont); + return size; +} + +VALUE +rb_obj_is_fiber(VALUE obj) +{ + return RBOOL(rb_typeddata_is_kind_of(obj, &rb_fiber_data_type)); +} + static void cont_save_machine_stack(rb_thread_t *th, rb_context_t *cont) { - int size; - rb_thread_t *sth = &cont->saved_thread; + const size_t old_stack_size = cont->machine.stack_size; + size_t size; - SET_MACHINE_STACK_END(&th->machine_stack_end); -#ifdef __ia64 - th->machine_register_stack_end = rb_ia64_bsp(); -#endif + SET_MACHINE_STACK_END(&th->ec->machine.stack_end); - if (th->machine_stack_start > th->machine_stack_end) { - size = cont->machine_stack_size = th->machine_stack_start - th->machine_stack_end; - cont->machine_stack_src = th->machine_stack_end; + if (th->ec->machine.stack_start > th->ec->machine.stack_end) { + size = cont->machine.stack_size = th->ec->machine.stack_start - th->ec->machine.stack_end; + cont->machine.stack_src = th->ec->machine.stack_end; } else { - size = cont->machine_stack_size = th->machine_stack_end - th->machine_stack_start; - cont->machine_stack_src = th->machine_stack_start; + size = cont->machine.stack_size = th->ec->machine.stack_end - th->ec->machine.stack_start; + cont->machine.stack_src = th->ec->machine.stack_start; } - if (cont->machine_stack) { - REALLOC_N(cont->machine_stack, VALUE, size); + if (cont->machine.stack) { + SIZED_REALLOC_N(cont->machine.stack, VALUE, cont->machine.stack_size, old_stack_size); } else { - cont->machine_stack = ALLOC_N(VALUE, size); + cont->machine.stack = ALLOC_N(VALUE, cont->machine.stack_size); } FLUSH_REGISTER_WINDOWS; - MEMCPY(cont->machine_stack, cont->machine_stack_src, VALUE, size); + asan_unpoison_memory_region(cont->machine.stack_src, size, false); + MEMCPY(cont->machine.stack, cont->machine.stack_src, VALUE, size); +} + +static void +cont_handle_weak_references(void *ptr) +{ + rb_context_t *cont = ptr; + + if (!cont) return; -#ifdef __ia64 - rb_ia64_flushrs(); - size = cont->machine_register_stack_size = th->machine_register_stack_end - th->machine_register_stack_start; - cont->machine_register_stack_src = th->machine_register_stack_start; - if (cont->machine_register_stack) { - REALLOC_N(cont->machine_register_stack, VALUE, size); + if (!rb_gc_handle_weak_references_alive_p(cont->saved_ec.gen_fields_cache.obj) || + !rb_gc_handle_weak_references_alive_p(cont->saved_ec.gen_fields_cache.fields_obj)) { + cont->saved_ec.gen_fields_cache.obj = Qundef; + cont->saved_ec.gen_fields_cache.fields_obj = Qundef; + } +} + +static const rb_data_type_t rb_cont_data_type = { + "continuation", + {cont_mark, cont_free, cont_memsize, cont_compact, cont_handle_weak_references}, + 0, 0, RUBY_TYPED_FREE_IMMEDIATELY +}; + +static inline void +cont_save_thread(rb_context_t *cont, rb_thread_t *th) +{ + rb_execution_context_t *sec = &cont->saved_ec; + + VM_ASSERT(th->status == THREAD_RUNNABLE); + + /* save thread context */ + *sec = *th->ec; + + /* saved_ec->machine.stack_end should be NULL */ + /* because it may happen GC afterward */ + sec->machine.stack_end = NULL; +} + +static rb_nativethread_lock_t jit_cont_lock; + +// Register a new continuation with execution context `ec`. Return JIT info about +// the continuation. +static struct rb_jit_cont * +jit_cont_new(rb_execution_context_t *ec) +{ + struct rb_jit_cont *cont; + + // We need to use calloc instead of something like ZALLOC to avoid triggering GC here. + // When this function is called from rb_thread_alloc through rb_threadptr_root_fiber_setup, + // the thread is still being prepared and marking it causes SEGV. + cont = ruby_mimcalloc(1, sizeof(struct rb_jit_cont)); + if (cont == NULL) + rb_memerror(); + cont->ec = ec; + + rb_native_mutex_lock(&jit_cont_lock); + if (first_jit_cont == NULL) { + cont->next = cont->prev = NULL; } else { - cont->machine_register_stack = ALLOC_N(VALUE, size); + cont->prev = NULL; + cont->next = first_jit_cont; + first_jit_cont->prev = cont; } + first_jit_cont = cont; + rb_native_mutex_unlock(&jit_cont_lock); - MEMCPY(cont->machine_register_stack, cont->machine_register_stack_src, VALUE, size); -#endif + return cont; +} - sth->machine_stack_start = sth->machine_stack_end = 0; -#ifdef __ia64 - sth->machine_register_stack_start = sth->machine_register_stack_end = 0; +// Unregister continuation `cont`. +static void +jit_cont_free(struct rb_jit_cont *cont) +{ + if (!cont) return; + + rb_native_mutex_lock(&jit_cont_lock); + if (cont == first_jit_cont) { + first_jit_cont = cont->next; + if (first_jit_cont != NULL) + first_jit_cont->prev = NULL; + } + else { + cont->prev->next = cont->next; + if (cont->next != NULL) + cont->next->prev = cont->prev; + } + rb_native_mutex_unlock(&jit_cont_lock); + + ruby_mimfree(cont); +} + +// Call a given callback against all on-stack ISEQs. +void +rb_jit_cont_each_iseq(rb_iseq_callback callback, void *data) +{ + struct rb_jit_cont *cont; + for (cont = first_jit_cont; cont != NULL; cont = cont->next) { + if (cont->ec->vm_stack == NULL) + continue; + + const rb_control_frame_t *cfp = cont->ec->cfp; + while (!RUBY_VM_CONTROL_FRAME_STACK_OVERFLOW_P(cont->ec, cfp)) { + if (CFP_PC(cfp) && CFP_ISEQ(cfp)) { + const rb_iseq_t *iseq = CFP_ISEQ(cfp); + if (iseq && imemo_type((VALUE)iseq) == imemo_iseq) { + callback(iseq, data); + } + } + cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp); + } + } +} + +#if USE_YJIT +// Update the jit_return of all CFPs to leave_exit unless it's leave_exception or not set. +// This prevents jit_exec_exception from jumping to the caller after invalidation. +void +rb_yjit_cancel_jit_return(void *leave_exit, void *leave_exception) +{ + struct rb_jit_cont *cont; + for (cont = first_jit_cont; cont != NULL; cont = cont->next) { + if (cont->ec->vm_stack == NULL) + continue; + + const rb_control_frame_t *cfp = cont->ec->cfp; + while (!RUBY_VM_CONTROL_FRAME_STACK_OVERFLOW_P(cont->ec, cfp)) { + if (cfp->jit_return && cfp->jit_return != leave_exception) { + ((rb_control_frame_t *)cfp)->jit_return = leave_exit; + } + cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp); + } + } +} #endif + +// Finish working with jit_cont. +void +rb_jit_cont_finish(void) +{ + struct rb_jit_cont *cont, *next; + for (cont = first_jit_cont; cont != NULL; cont = next) { + next = cont->next; + ruby_mimfree(cont); // Don't use xfree because it's allocated by mimcalloc. + } + rb_native_mutex_destroy(&jit_cont_lock); +} + +static void +cont_init_jit_cont(rb_context_t *cont) +{ + VM_ASSERT(cont->jit_cont == NULL); + // We always allocate this since YJIT may be enabled later + cont->jit_cont = jit_cont_new(&(cont->saved_ec)); +} + +struct rb_execution_context_struct * +rb_fiberptr_get_ec(struct rb_fiber_struct *fiber) +{ + return &fiber->cont.saved_ec; +} + +static void +cont_init(rb_context_t *cont, rb_thread_t *th) +{ + /* save thread context */ + cont_save_thread(cont, th); + cont->saved_ec.thread_ptr = th; + cont->saved_ec.local_storage = NULL; + cont->saved_ec.local_storage_recursive_hash = Qnil; + cont->saved_ec.local_storage_recursive_hash_for_trace = Qnil; + cont_init_jit_cont(cont); } static rb_context_t * @@ -158,230 +1534,403 @@ cont_new(VALUE klass) volatile VALUE contval; rb_thread_t *th = GET_THREAD(); - contval = Data_Make_Struct(klass, rb_context_t, cont_mark, cont_free, cont); - + THREAD_MUST_BE_RUNNING(th); + contval = TypedData_Make_Struct(klass, rb_context_t, &rb_cont_data_type, cont); + rb_gc_declare_weak_references(contval); cont->self = contval; - cont->alive = Qtrue; + cont_init(cont, th); + return cont; +} - /* save thread context */ - cont->saved_thread = *th; +VALUE +rb_fiberptr_self(struct rb_fiber_struct *fiber) +{ + return fiber->cont.self; +} - return cont; +unsigned int +rb_fiberptr_blocking(struct rb_fiber_struct *fiber) +{ + return fiber->blocking; } -void vm_stack_to_heap(rb_thread_t *th); +// Initialize the jit_cont_lock +void +rb_jit_cont_init(void) +{ + rb_native_mutex_initialize(&jit_cont_lock); +} + +#if 0 +void +show_vm_stack(const rb_execution_context_t *ec) +{ + VALUE *p = ec->vm_stack; + while (p < ec->cfp->sp) { + fprintf(stderr, "%3d ", (int)(p - ec->vm_stack)); + rb_obj_info_dump(*p); + p++; + } +} + +void +show_vm_pcs(const rb_control_frame_t *cfp, + const rb_control_frame_t *end_of_cfp) +{ + int i=0; + while (cfp != end_of_cfp) { + int pc = 0; + if (CFP_ISEQ(cfp)) { + pc = cfp->pc - ISEQ_BODY(CFP_ISEQ(cfp))->iseq_encoded; + } + fprintf(stderr, "%2d pc: %d\n", i++, pc); + cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp); + } +} +#endif static VALUE -cont_capture(volatile int *stat) +cont_capture(volatile int *volatile stat) { - rb_context_t *cont; - rb_thread_t *th = GET_THREAD(), *sth; + rb_context_t *volatile cont; + rb_thread_t *th = GET_THREAD(); volatile VALUE contval; + const rb_execution_context_t *ec = th->ec; - vm_stack_to_heap(th); + THREAD_MUST_BE_RUNNING(th); + rb_vm_stack_to_heap(th->ec); cont = cont_new(rb_cContinuation); contval = cont->self; - sth = &cont->saved_thread; - - cont->vm_stack = ALLOC_N(VALUE, th->stack_size); - MEMCPY(cont->vm_stack, th->stack, VALUE, th->stack_size); - sth->stack = 0; +#ifdef CAPTURE_JUST_VALID_VM_STACK + cont->saved_vm_stack.slen = ec->cfp->sp - ec->vm_stack; + cont->saved_vm_stack.clen = ec->vm_stack + ec->vm_stack_size - (VALUE*)ec->cfp; + cont->saved_vm_stack.size = cont->saved_vm_stack.slen + cont->saved_vm_stack.clen; + cont->saved_vm_stack.ptr = ALLOC_N(VALUE, cont->saved_vm_stack.slen + cont->saved_vm_stack.clen); + MEMCPY(cont->saved_vm_stack.ptr, + ec->vm_stack, + VALUE, cont->saved_vm_stack.slen); + MEMCPY(cont->saved_vm_stack.ptr + cont->saved_vm_stack.slen, + (VALUE*)ec->cfp, + VALUE, + cont->saved_vm_stack.clen); +#else + cont->saved_vm_stack.size = ec->vm_stack_size; + cont->saved_vm_stack.ptr = ALLOC_N(VALUE, ec->vm_stack_size); + MEMCPY(cont->saved_vm_stack.ptr, ec->vm_stack, VALUE, ec->vm_stack_size); +#endif + // At this point, `cfp` is valid but `vm_stack` should be cleared: + rb_ec_set_vm_stack(&cont->saved_ec, NULL, 0); + VM_ASSERT(cont->saved_ec.cfp != NULL); cont_save_machine_stack(th, cont); if (ruby_setjmp(cont->jmpbuf)) { - VALUE value; - - value = cont->value; - cont->value = Qnil; - *stat = 1; - return value; + VALUE value; + + VAR_INITIALIZED(cont); + value = cont->value; + if (cont->argc == -1) rb_exc_raise(value); + cont->value = Qnil; + *stat = 1; + return value; } else { - *stat = 0; - return cont->self; + *stat = 0; + return contval; } } -NORETURN(static void cont_restore_1(rb_context_t *)); - -static void -cont_restore_1(rb_context_t *cont) +static inline void +cont_restore_thread(rb_context_t *cont) { - rb_thread_t *th = GET_THREAD(), *sth = &cont->saved_thread; + rb_thread_t *th = GET_THREAD(); /* restore thread context */ if (cont->type == CONTINUATION_CONTEXT) { - /* continuation */ - VALUE fib; + /* continuation */ + rb_execution_context_t *sec = &cont->saved_ec; + rb_fiber_t *fiber = NULL; + + if (sec->fiber_ptr != NULL) { + fiber = sec->fiber_ptr; + } + else if (th->root_fiber) { + fiber = th->root_fiber; + } + + if (fiber && th->ec != &fiber->cont.saved_ec) { + ec_switch(th, fiber); + } + + if (th->ec->trace_arg != sec->trace_arg) { + rb_raise(rb_eRuntimeError, "can't call across trace_func"); + } + +#if defined(__wasm__) && !defined(__EMSCRIPTEN__) + if (th->ec->tag != sec->tag) { + /* find the lowest common ancestor tag of the current EC and the saved EC */ + + struct rb_vm_tag *lowest_common_ancestor = NULL; + size_t num_tags = 0; + size_t num_saved_tags = 0; + for (struct rb_vm_tag *tag = th->ec->tag; tag != NULL; tag = tag->prev) { + ++num_tags; + } + for (struct rb_vm_tag *tag = sec->tag; tag != NULL; tag = tag->prev) { + ++num_saved_tags; + } + + size_t min_tags = num_tags <= num_saved_tags ? num_tags : num_saved_tags; + + struct rb_vm_tag *tag = th->ec->tag; + while (num_tags > min_tags) { + tag = tag->prev; + --num_tags; + } + + struct rb_vm_tag *saved_tag = sec->tag; + while (num_saved_tags > min_tags) { + saved_tag = saved_tag->prev; + --num_saved_tags; + } + + while (min_tags > 0) { + if (tag == saved_tag) { + lowest_common_ancestor = tag; + break; + } + tag = tag->prev; + saved_tag = saved_tag->prev; + --min_tags; + } + + /* free all the jump buffers between the current EC's tag and the lowest common ancestor tag */ + for (struct rb_vm_tag *tag = th->ec->tag; tag != lowest_common_ancestor; tag = tag->prev) { + rb_vm_tag_jmpbuf_deinit(&tag->buf); + } + } +#endif + + /* copy vm stack */ +#ifdef CAPTURE_JUST_VALID_VM_STACK + MEMCPY(th->ec->vm_stack, + cont->saved_vm_stack.ptr, + VALUE, cont->saved_vm_stack.slen); + MEMCPY(th->ec->vm_stack + th->ec->vm_stack_size - cont->saved_vm_stack.clen, + cont->saved_vm_stack.ptr + cont->saved_vm_stack.slen, + VALUE, cont->saved_vm_stack.clen); +#else + MEMCPY(th->ec->vm_stack, cont->saved_vm_stack.ptr, VALUE, sec->vm_stack_size); +#endif + /* other members of ec */ - th->fiber = sth->fiber; - fib = th->fiber ? th->fiber : th->root_fiber; + th->ec->cfp = sec->cfp; + th->ec->raised_flag = sec->raised_flag; + th->ec->tag = sec->tag; + th->ec->root_lep = sec->root_lep; + th->ec->root_svar = sec->root_svar; + th->ec->errinfo = sec->errinfo; - if (fib) { - rb_context_t *fcont; - GetContPtr(fib, fcont); - th->stack_size = fcont->saved_thread.stack_size; - th->stack = fcont->saved_thread.stack; - } - MEMCPY(th->stack, cont->vm_stack, VALUE, sth->stack_size); + VM_ASSERT(th->ec->vm_stack != NULL); } else { - /* fiber */ - th->stack = sth->stack; - th->stack_size = sth->stack_size; - th->local_storage = sth->local_storage; - th->fiber = cont->self; - } - - th->cfp = sth->cfp; - th->safe_level = sth->safe_level; - th->raised_flag = sth->raised_flag; - th->state = sth->state; - th->status = sth->status; - th->tag = sth->tag; - th->trap_tag = sth->trap_tag; - th->errinfo = sth->errinfo; - th->first_proc = sth->first_proc; + /* fiber */ + fiber_restore_thread(th, (rb_fiber_t*)cont); + } +} - /* restore machine stack */ -#ifdef _M_AMD64 - { - /* workaround for x64 SEH */ - jmp_buf buf; - setjmp(buf); - ((_JUMP_BUFFER*)(&cont->jmpbuf))->Frame = - ((_JUMP_BUFFER*)(&buf))->Frame; +NOINLINE(static void fiber_setcontext(rb_fiber_t *new_fiber, rb_fiber_t *old_fiber)); + +static void +fiber_setcontext(rb_fiber_t *new_fiber, rb_fiber_t *old_fiber) +{ + rb_thread_t *th = GET_THREAD(); + + /* save old_fiber's machine stack - to ensure efficient garbage collection */ + if (!FIBER_TERMINATED_P(old_fiber)) { + STACK_GROW_DIR_DETECTION; + SET_MACHINE_STACK_END(&th->ec->machine.stack_end); + if (STACK_DIR_UPPER(0, 1)) { + old_fiber->cont.machine.stack_size = th->ec->machine.stack_start - th->ec->machine.stack_end; + old_fiber->cont.machine.stack = th->ec->machine.stack_end; + } + else { + old_fiber->cont.machine.stack_size = th->ec->machine.stack_end - th->ec->machine.stack_start; + old_fiber->cont.machine.stack = th->ec->machine.stack_start; + } } + + /* these values are used in rb_gc_mark_machine_context to mark the fiber's stack. */ + old_fiber->cont.saved_ec.machine.stack_start = th->ec->machine.stack_start; + old_fiber->cont.saved_ec.machine.stack_end = FIBER_TERMINATED_P(old_fiber) ? NULL : th->ec->machine.stack_end; + + + // if (DEBUG) fprintf(stderr, "fiber_setcontext: %p[%p] -> %p[%p]\n", (void*)old_fiber, old_fiber->stack.base, (void*)new_fiber, new_fiber->stack.base); + +#if defined(COROUTINE_SANITIZE_ADDRESS) + __sanitizer_start_switch_fiber(FIBER_TERMINATED_P(old_fiber) ? NULL : &old_fiber->context.fake_stack, new_fiber->context.stack_base, new_fiber->context.stack_size); #endif - if (cont->machine_stack_src) { - FLUSH_REGISTER_WINDOWS; - MEMCPY(cont->machine_stack_src, cont->machine_stack, - VALUE, cont->machine_stack_size); - } -#ifdef __ia64 - if (cont->machine_register_stack_src) { - MEMCPY(cont->machine_register_stack_src, cont->machine_register_stack, - VALUE, cont->machine_register_stack_size); - } + /* swap machine context */ + struct coroutine_context * from = coroutine_transfer(&old_fiber->context, &new_fiber->context); + +#if defined(COROUTINE_SANITIZE_ADDRESS) + __sanitizer_finish_switch_fiber(old_fiber->context.fake_stack, NULL, NULL); #endif - ruby_longjmp(cont->jmpbuf, 1); + if (from == NULL) { + rb_syserr_fail(errno, "coroutine_transfer"); + } + + /* restore thread context */ + fiber_restore_thread(th, old_fiber); + + // It's possible to get here, and new_fiber is already freed. + // if (DEBUG) fprintf(stderr, "fiber_setcontext: %p[%p] <- %p[%p]\n", (void*)old_fiber, old_fiber->stack.base, (void*)new_fiber, new_fiber->stack.base); } -NORETURN(NOINLINE(static void cont_restore_0(rb_context_t *, VALUE *))); +NOINLINE(NORETURN(static void cont_restore_1(rb_context_t *))); -#ifdef __ia64 -#define C(a) rse_##a##0, rse_##a##1, rse_##a##2, rse_##a##3, rse_##a##4 -#define E(a) rse_##a##0= rse_##a##1= rse_##a##2= rse_##a##3= rse_##a##4 -static volatile int C(a), C(b), C(c), C(d), C(e); -static volatile int C(f), C(g), C(h), C(i), C(j); -static volatile int C(k), C(l), C(m), C(n), C(o); -static volatile int C(p), C(q), C(r), C(s), C(t); -int rb_dummy_false = 0; -NORETURN(NOINLINE(static void register_stack_extend(rb_context_t *, VALUE *))); static void -register_stack_extend(rb_context_t *cont, VALUE *curr_bsp) -{ - if (rb_dummy_false) { - /* use registers as much as possible */ - E(a) = E(b) = E(c) = E(d) = E(e) = - E(f) = E(g) = E(h) = E(i) = E(j) = - E(k) = E(l) = E(m) = E(n) = E(o) = - E(p) = E(q) = E(r) = E(s) = E(t) = 0; - E(a) = E(b) = E(c) = E(d) = E(e) = - E(f) = E(g) = E(h) = E(i) = E(j) = - E(k) = E(l) = E(m) = E(n) = E(o) = - E(p) = E(q) = E(r) = E(s) = E(t) = 0; - } - if (curr_bsp < cont->machine_register_stack_src+cont->machine_register_stack_size) { - register_stack_extend(cont, (VALUE*)rb_ia64_bsp()); +cont_restore_1(rb_context_t *cont) +{ + cont_restore_thread(cont); + + /* restore machine stack */ +#if (defined(_M_AMD64) && !defined(__MINGW64__)) || defined(_M_ARM64) + { + /* workaround for x64 and arm64 SEH on Windows */ + jmp_buf buf; + setjmp(buf); + _JUMP_BUFFER *bp = (void*)&cont->jmpbuf; + bp->Frame = ((_JUMP_BUFFER*)((void*)&buf))->Frame; } - cont_restore_1(cont); -} -#undef C -#undef E #endif + if (cont->machine.stack_src) { + FLUSH_REGISTER_WINDOWS; + MEMCPY(cont->machine.stack_src, cont->machine.stack, + VALUE, cont->machine.stack_size); + } + + ruby_longjmp(cont->jmpbuf, 1); +} + +NORETURN(NOINLINE(static void cont_restore_0(rb_context_t *, VALUE *))); static void cont_restore_0(rb_context_t *cont, VALUE *addr_in_prev_frame) { - if (cont->machine_stack_src) { -#define STACK_PAD_SIZE 1024 - VALUE space[STACK_PAD_SIZE]; - -#if STACK_GROW_DIRECTION < 0 /* downward */ - if (addr_in_prev_frame > cont->machine_stack_src) { - cont_restore_0(cont, &space[0]); - } -#elif STACK_GROW_DIRECTION > 0 /* upward */ - if (addr_in_prev_frame < cont->machine_stack_src + cont->machine_stack_size) { - cont_restore_0(cont, &space[STACK_PAD_SIZE-1]); - } -#else - if (addr_in_prev_frame > &space[0]) { - /* Stack grows downward */ - if (addr_in_prev_frame > cont->machine_stack_src) { - cont_restore_0(cont, &space[0]); - } - } - else { - /* Stack grows upward */ - if (addr_in_prev_frame < cont->machine_stack_src + cont->machine_stack_size) { - cont_restore_0(cont, &space[STACK_PAD_SIZE-1]); - } - } -#endif - } -#ifdef __ia64 - register_stack_extend(cont, (VALUE*)rb_ia64_bsp()); + if (cont->machine.stack_src) { +#ifdef HAVE_ALLOCA +#define STACK_PAD_SIZE 1 #else - cont_restore_1(cont); +#define STACK_PAD_SIZE 1024 +#endif + VALUE space[STACK_PAD_SIZE]; + +#if !STACK_GROW_DIRECTION + if (addr_in_prev_frame > &space[0]) { + /* Stack grows downward */ #endif +#if STACK_GROW_DIRECTION <= 0 + volatile VALUE *const end = cont->machine.stack_src; + if (&space[0] > end) { +# ifdef HAVE_ALLOCA + volatile VALUE *sp = ALLOCA_N(VALUE, &space[0] - end); + // We need to make sure that the stack pointer is moved, + // but some compilers may remove the allocation by optimization. + // We hope that the following read/write will prevent such an optimization. + *sp = Qfalse; + space[0] = *sp; +# else + cont_restore_0(cont, &space[0]); +# endif + } +#endif +#if !STACK_GROW_DIRECTION + } + else { + /* Stack grows upward */ +#endif +#if STACK_GROW_DIRECTION >= 0 + volatile VALUE *const end = cont->machine.stack_src + cont->machine.stack_size; + if (&space[STACK_PAD_SIZE] < end) { +# ifdef HAVE_ALLOCA + volatile VALUE *sp = ALLOCA_N(VALUE, end - &space[STACK_PAD_SIZE]); + space[0] = *sp; +# else + cont_restore_0(cont, &space[STACK_PAD_SIZE-1]); +# endif + } +#endif +#if !STACK_GROW_DIRECTION + } +#endif + } + cont_restore_1(cont); } /* * Document-class: Continuation * - * Continuation objects are generated by - * <code>Kernel#callcc</code>. They hold a return address and execution - * context, allowing a nonlocal return to the end of the - * <code>callcc</code> block from anywhere within a program. - * Continuations are somewhat analogous to a structured version of C's - * <code>setjmp/longjmp</code> (although they contain more state, so - * you might consider them closer to threads). - * + * Continuation objects are generated by Kernel#callcc, + * after having +require+d <i>continuation</i>. They hold + * a return address and execution context, allowing a nonlocal return + * to the end of the #callcc block from anywhere within a + * program. Continuations are somewhat analogous to a structured + * version of C's <code>setjmp/longjmp</code> (although they contain + * more state, so you might consider them closer to threads). + * * For instance: - * + * + * require "continuation" * arr = [ "Freddie", "Herbie", "Ron", "Max", "Ringo" ] - * callcc{|$cc|} + * callcc{|cc| $cc = cc} * puts(message = arr.shift) * $cc.call unless message =~ /Max/ - * + * * <em>produces:</em> - * + * * Freddie * Herbie * Ron * Max - * + * + * Also you can call callcc in other methods: + * + * require "continuation" + * + * def g + * arr = [ "Freddie", "Herbie", "Ron", "Max", "Ringo" ] + * cc = callcc { |cc| cc } + * puts arr.shift + * return cc, arr.size + * end + * + * def f + * c, size = g + * c.call(c) if size > 1 + * end + * + * f + * * This (somewhat contrived) example allows the inner loop to abandon * processing early: - * + * + * require "continuation" * callcc {|cont| * for i in 0..4 - * print "\n#{i}: " + * print "#{i}: " * for j in i*5...(i+1)*5 * cont.call() if j == 17 * printf "%3d", j * end * end * } - * print "\n" - * + * puts + * * <em>produces:</em> - * + * * 0: 0 1 2 3 4 * 1: 5 6 7 8 9 * 2: 10 11 12 13 14 @@ -390,16 +1939,18 @@ cont_restore_0(rb_context_t *cont, VALUE *addr_in_prev_frame) /* * call-seq: - * callcc {|cont| block } => obj - * - * Generates a <code>Continuation</code> object, which it passes to the - * associated block. Performing a <em>cont</em><code>.call</code> will - * cause the <code>callcc</code> to return (as will falling through the - * end of the block). The value returned by the <code>callcc</code> is - * the value of the block, or the value passed to - * <em>cont</em><code>.call</code>. See class <code>Continuation</code> - * for more details. Also see <code>Kernel::throw</code> for - * an alternative mechanism for unwinding a call stack. + * callcc {|cont| block } -> obj + * + * Generates a Continuation object, which it passes to + * the associated block. You need to <code>require + * 'continuation'</code> before using this method. Performing a + * <em>cont</em><code>.call</code> will cause the #callcc + * to return (as will falling through the end of the block). The + * value returned by the #callcc is the value of the + * block, or the value passed to <em>cont</em><code>.call</code>. See + * class Continuation for more details. Also see + * Kernel#throw for an alternative mechanism for + * unwinding a call stack. */ static VALUE @@ -409,37 +1960,49 @@ rb_callcc(VALUE self) volatile VALUE val = cont_capture(&called); if (called) { - return val; + return val; } else { - return rb_yield(val); + return rb_yield(val); } } +#ifdef RUBY_ASAN_ENABLED +/* callcc can't possibly work with ASAN; see bug #20273. Also this function + * definition below avoids a "defined and not used" warning. */ +MAYBE_UNUSED(static void notusing_callcc(void)) { rb_callcc(Qnil); } +# define rb_callcc rb_f_notimplement +#endif + static VALUE -make_passing_arg(int argc, VALUE *argv) +make_passing_arg(int argc, const VALUE *argv) { - switch(argc) { + switch (argc) { + case -1: + return argv[0]; case 0: - return Qnil; + return Qnil; case 1: - return argv[0]; + return argv[0]; default: - return rb_ary_new4(argc, argv); + return rb_ary_new4(argc, argv); } } +typedef VALUE e_proc(VALUE); + +NORETURN(static VALUE rb_cont_call(int argc, VALUE *argv, VALUE contval)); + /* * call-seq: * cont.call(args, ...) * cont[args, ...] - * - * Invokes the continuation. The program continues from the end of the - * <code>callcc</code> block. If no arguments are given, the original - * <code>callcc</code> returns <code>nil</code>. If one argument is - * given, <code>callcc</code> returns it. Otherwise, an array - * containing <i>args</i> is returned. - * + * + * Invokes the continuation. The program continues from the end of + * the #callcc block. If no arguments are given, the original #callcc + * returns +nil+. If one argument is given, #callcc returns + * it. Otherwise, an array containing <i>args</i> is returned. + * * callcc {|cont| cont.call } #=> nil * callcc {|cont| cont.call 1 } #=> 1 * callcc {|cont| cont.call 1, 2, 3 } #=> [1, 2, 3] @@ -448,320 +2011,1720 @@ make_passing_arg(int argc, VALUE *argv) static VALUE rb_cont_call(int argc, VALUE *argv, VALUE contval) { - rb_context_t *cont; + rb_context_t *cont = cont_ptr(contval); rb_thread_t *th = GET_THREAD(); - GetContPtr(contval, cont); - if (cont->saved_thread.self != th->self) { - rb_raise(rb_eRuntimeError, "continuation called across threads"); - } - if (cont->saved_thread.trap_tag != th->trap_tag) { - rb_raise(rb_eRuntimeError, "continuation called across trap"); + if (cont_thread_value(cont) != th->self) { + rb_raise(rb_eRuntimeError, "continuation called across threads"); } - if (cont->saved_thread.fiber) { - rb_context_t *fcont; - GetContPtr(cont->saved_thread.fiber, fcont); - - if (th->fiber != cont->saved_thread.fiber) { - rb_raise(rb_eRuntimeError, "continuation called across fiber"); - } - - if (!fcont->alive) { - rb_raise(rb_eRuntimeError, "continuation called dead fiber"); - } + if (cont->saved_ec.fiber_ptr) { + if (th->ec->fiber_ptr != cont->saved_ec.fiber_ptr) { + rb_raise(rb_eRuntimeError, "continuation called across fiber"); + } } + cont->argc = argc; cont->value = make_passing_arg(argc, argv); cont_restore_0(cont, &contval); - return Qnil; /* unreachable */ + UNREACHABLE_RETURN(Qnil); } /*********/ /* fiber */ /*********/ -#define FIBER_VM_STACK_SIZE (4 * 1024) +/* + * Document-class: Fiber + * + * Fibers are primitives for implementing light weight cooperative + * concurrency in Ruby. Basically they are a means of creating code blocks + * that can be paused and resumed, much like threads. The main difference + * is that they are never preempted and that the scheduling must be done by + * the programmer and not the VM. + * + * As opposed to other stackless light weight concurrency models, each fiber + * comes with a stack. This enables the fiber to be paused from deeply + * nested function calls within the fiber block. See the ruby(1) + * manpage to configure the size of the fiber stack(s). + * + * When a fiber is created it will not run automatically. Rather it must + * be explicitly asked to run using the Fiber#resume method. + * The code running inside the fiber can give up control by calling + * Fiber.yield in which case it yields control back to caller (the + * caller of the Fiber#resume). + * + * Upon yielding or termination the Fiber returns the value of the last + * executed expression + * + * For instance: + * + * fiber = Fiber.new do + * Fiber.yield 1 + * 2 + * end + * + * puts fiber.resume + * puts fiber.resume + * puts fiber.resume + * + * <em>produces</em> + * + * 1 + * 2 + * FiberError: dead fiber called + * + * The Fiber#resume method accepts an arbitrary number of parameters, + * if it is the first call to #resume then they will be passed as + * block arguments. Otherwise they will be the return value of the + * call to Fiber.yield + * + * Example: + * + * fiber = Fiber.new do |first| + * second = Fiber.yield first + 2 + * end + * + * puts fiber.resume 10 + * puts fiber.resume 1_000_000 + * puts fiber.resume "The fiber will be dead before I can cause trouble" + * + * <em>produces</em> + * + * 12 + * 1000000 + * FiberError: dead fiber called + * + * == Non-blocking Fibers + * + * The concept of <em>non-blocking fiber</em> was introduced in Ruby 3.0. + * A non-blocking fiber, when reaching an operation that would normally block + * the fiber (like <code>sleep</code>, or wait for another process or I/O) + * will yield control to other fibers and allow the <em>scheduler</em> to + * handle blocking and waking up (resuming) this fiber when it can proceed. + * + * For a Fiber to behave as non-blocking, it need to be created in Fiber.new with + * <tt>blocking: false</tt> (which is the default), and Fiber.scheduler + * should be set with Fiber.set_scheduler. If Fiber.scheduler is not set in + * the current thread, blocking and non-blocking fibers' behavior is identical. + * + * Ruby doesn't provide a scheduler class: it is expected to be implemented by + * the user and correspond to Fiber::Scheduler. + * + * There is also Fiber.schedule method, which is expected to immediately perform + * the given block in a non-blocking manner. Its actual implementation is up to + * the scheduler. + * + */ -static rb_context_t * +static void +fiber_handle_weak_references(void *ptr) +{ + rb_fiber_t *fiber = ptr; + + if (!fiber) return; + + if (!rb_gc_handle_weak_references_alive_p(fiber->cont.saved_ec.gen_fields_cache.obj) || + !rb_gc_handle_weak_references_alive_p(fiber->cont.saved_ec.gen_fields_cache.fields_obj)) { + fiber->cont.saved_ec.gen_fields_cache.obj = Qundef; + fiber->cont.saved_ec.gen_fields_cache.fields_obj = Qundef; + } +} + +static const rb_data_type_t rb_fiber_data_type = { + "fiber", + {fiber_mark, fiber_free, fiber_memsize, fiber_compact, fiber_handle_weak_references}, + 0, 0, RUBY_TYPED_FREE_IMMEDIATELY +}; + +static VALUE fiber_alloc(VALUE klass) { - rb_context_t *cont = cont_new(klass); + VALUE obj = TypedData_Wrap_Struct(klass, &rb_fiber_data_type, 0); + rb_gc_declare_weak_references(obj); + return obj; +} - cont->type = FIBER_CONTEXT; - cont->prev = Qnil; +static rb_serial_t +next_ec_serial(rb_ractor_t *cr) +{ + return cr->next_ec_serial++; +} - return cont; +static rb_fiber_t* +fiber_t_alloc(VALUE fiber_value, unsigned int blocking) +{ + rb_fiber_t *fiber; + rb_thread_t *th = GET_THREAD(); + + if (DATA_PTR(fiber_value) != 0) { + rb_raise(rb_eRuntimeError, "cannot initialize twice"); + } + + THREAD_MUST_BE_RUNNING(th); + fiber = ZALLOC(rb_fiber_t); + fiber->cont.self = fiber_value; + fiber->cont.type = FIBER_CONTEXT; + fiber->blocking = blocking; + fiber->killed = 0; + cont_init(&fiber->cont, th); + + fiber->cont.saved_ec.fiber_ptr = fiber; + fiber->cont.saved_ec.serial = next_ec_serial(th->ractor); + rb_ec_clear_vm_stack(&fiber->cont.saved_ec); + + fiber->prev = NULL; + + /* fiber->status == 0 == CREATED + * So that we don't need to set status: fiber_status_set(fiber, FIBER_CREATED); */ + VM_ASSERT(FIBER_CREATED_P(fiber)); + + DATA_PTR(fiber_value) = fiber; + + return fiber; +} + +static inline rb_fiber_t* +fiber_current(void) +{ + rb_execution_context_t *ec = GET_EC(); + return ec->fiber_ptr; +} + +static inline VALUE +current_fiber_storage(void) +{ + rb_execution_context_t *ec = GET_EC(); + return ec->storage; } +static inline VALUE +inherit_fiber_storage(void) +{ + return rb_obj_dup(current_fiber_storage()); +} + +static inline void +fiber_storage_set(struct rb_fiber_struct *fiber, VALUE storage) +{ + fiber->cont.saved_ec.storage = storage; +} + +static inline VALUE +fiber_storage_get(rb_fiber_t *fiber, int allocate) +{ + VALUE storage = fiber->cont.saved_ec.storage; + if (storage == Qnil && allocate) { + storage = rb_hash_new(); + fiber_storage_set(fiber, storage); + } + return storage; +} + +static void +storage_access_must_be_from_same_fiber(VALUE self) +{ + rb_fiber_t *fiber = fiber_ptr(self); + rb_fiber_t *current = fiber_current(); + if (fiber != current) { + rb_raise(rb_eArgError, "Fiber storage can only be accessed from the Fiber it belongs to"); + } +} + +/** + * call-seq: fiber.storage -> hash (dup) + * + * Returns a copy of the storage hash for the fiber. The method can only be called on the + * Fiber.current. + */ static VALUE -fiber_new(VALUE klass, VALUE proc) +rb_fiber_storage_get(VALUE self) { - rb_context_t *cont = fiber_alloc(klass); - VALUE contval = cont->self; - rb_thread_t *th = &cont->saved_thread; + storage_access_must_be_from_same_fiber(self); - /* initialize */ - cont->vm_stack = 0; + VALUE storage = fiber_storage_get(fiber_ptr(self), FALSE); - th->stack = 0; - th->stack_size = FIBER_VM_STACK_SIZE; - th->stack = ALLOC_N(VALUE, th->stack_size); + if (storage == Qnil) { + return Qnil; + } + else { + return rb_obj_dup(storage); + } +} - th->cfp = (void *)(th->stack + th->stack_size); - th->cfp--; - th->cfp->pc = 0; - th->cfp->sp = th->stack + 1; - th->cfp->bp = 0; - th->cfp->lfp = th->stack; - *th->cfp->lfp = 0; - th->cfp->dfp = th->stack; - th->cfp->self = Qnil; - th->cfp->flag = 0; - th->cfp->iseq = 0; - th->cfp->proc = 0; - th->cfp->block_iseq = 0; - th->tag = 0; - th->local_storage = st_init_numtable(); +static int +fiber_storage_validate_each(VALUE key, VALUE value, VALUE _argument) +{ + Check_Type(key, T_SYMBOL); - th->first_proc = proc; + return ST_CONTINUE; +} - MEMCPY(&cont->jmpbuf, &th->root_jmpbuf, rb_jmpbuf_t, 1); +static void +fiber_storage_validate(VALUE value) +{ + // nil is an allowed value and will be lazily initialized. + if (value == Qnil) return; - return contval; + if (!RB_TYPE_P(value, T_HASH)) { + rb_raise(rb_eTypeError, "storage must be a hash"); + } + + if (RB_OBJ_FROZEN(value)) { + rb_raise(rb_eFrozenError, "storage must not be frozen"); + } + + rb_hash_foreach(value, fiber_storage_validate_each, Qundef); } -VALUE -rb_fiber_new(VALUE (*func)(ANYARGS), VALUE obj) +/** + * call-seq: fiber.storage = hash + * + * Sets the storage hash for the fiber. This feature is experimental + * and may change in the future. The method can only be called on the + * Fiber.current. + * + * You should be careful about using this method as you may inadvertently clear + * important fiber-storage state. You should mostly prefer to assign specific + * keys in the storage using Fiber::[]=. + * + * You can also use <tt>Fiber.new(storage: nil)</tt> to create a fiber with an empty + * storage. + * + * Example: + * + * while request = request_queue.pop + * # Reset the per-request state: + * Fiber.current.storage = nil + * handle_request(request) + * end + */ +static VALUE +rb_fiber_storage_set(VALUE self, VALUE value) { - return fiber_new(rb_cFiber, rb_proc_new(func, obj)); + if (rb_warning_category_enabled_p(RB_WARN_CATEGORY_EXPERIMENTAL)) { + rb_category_warn(RB_WARN_CATEGORY_EXPERIMENTAL, + "Fiber#storage= is experimental and may be removed in the future!"); + } + + storage_access_must_be_from_same_fiber(self); + fiber_storage_validate(value); + + fiber_ptr(self)->cont.saved_ec.storage = rb_obj_dup(value); + return value; } +/** + * call-seq: Fiber[key] -> value + * + * Returns the value of the fiber storage variable identified by +key+. + * + * The +key+ must be a symbol, and the value is set by Fiber#[]= or + * Fiber#storage. + * + * See also Fiber::[]=. + */ static VALUE -rb_fiber_s_new(VALUE self) +rb_fiber_storage_aref(VALUE class, VALUE key) { - return fiber_new(self, rb_block_proc()); + key = rb_to_symbol(key); + + VALUE storage = fiber_storage_get(fiber_current(), FALSE); + if (storage == Qnil) return Qnil; + + return rb_hash_aref(storage, key); } +/** + * call-seq: Fiber[key] = value + * + * Assign +value+ to the fiber storage variable identified by +key+. + * The variable is created if it doesn't exist. + * + * +key+ must be a Symbol, otherwise a TypeError is raised. + * + * See also Fiber::[]. + */ static VALUE -return_fiber(void) +rb_fiber_storage_aset(VALUE class, VALUE key, VALUE value) { - rb_context_t *cont; - VALUE curr = rb_fiber_current(); - GetContPtr(curr, cont); + key = rb_to_symbol(key); - if (cont->prev == Qnil) { - rb_thread_t *th = GET_THREAD(); + VALUE storage = fiber_storage_get(fiber_current(), value != Qnil); + if (storage == Qnil) return Qnil; - if (th->root_fiber != curr) { - return th->root_fiber; - } - else { - rb_raise(rb_eFiberError, "can't yield from root fiber"); - } + if (value == Qnil) { + return rb_hash_delete(storage, key); } else { - VALUE prev = cont->prev; - cont->prev = Qnil; - return prev; + return rb_hash_aset(storage, key, value); } } -VALUE rb_fiber_transfer(VALUE fib, int argc, VALUE *argv); +static VALUE +fiber_initialize(VALUE self, VALUE proc, struct fiber_pool * fiber_pool, unsigned int blocking, VALUE storage) +{ + if (storage == Qundef || storage == Qtrue) { + // The default, inherit storage (dup) from the current fiber: + storage = inherit_fiber_storage(); + } + else /* nil, hash, etc. */ { + fiber_storage_validate(storage); + storage = rb_obj_dup(storage); + } + + rb_fiber_t *fiber = fiber_t_alloc(self, blocking); + + fiber->cont.saved_ec.storage = storage; + fiber->first_proc = proc; + fiber->stack.base = NULL; + fiber->stack.pool = fiber_pool; + + return self; +} static void -rb_fiber_terminate(rb_context_t *cont) +fiber_prepare_stack(rb_fiber_t *fiber) +{ + rb_context_t *cont = &fiber->cont; + rb_execution_context_t *sec = &cont->saved_ec; + + size_t vm_stack_size = 0; + VALUE *vm_stack = fiber_initialize_coroutine(fiber, &vm_stack_size); + + /* initialize cont */ + cont->saved_vm_stack.ptr = NULL; + rb_ec_initialize_vm_stack(sec, vm_stack, vm_stack_size / sizeof(VALUE)); + + sec->tag = NULL; + sec->local_storage = NULL; + sec->local_storage_recursive_hash = Qnil; + sec->local_storage_recursive_hash_for_trace = Qnil; +} + +static struct fiber_pool * +rb_fiber_pool_default(VALUE pool) +{ + return &shared_fiber_pool; +} + +VALUE rb_fiber_inherit_storage(struct rb_execution_context_struct *ec, struct rb_fiber_struct *fiber) { - VALUE value = cont->value; - cont->alive = Qfalse; - rb_fiber_transfer(return_fiber(), 1, &value); + VALUE storage = rb_obj_dup(ec->storage); + fiber->cont.saved_ec.storage = storage; + return storage; } +/* :nodoc: */ +static VALUE +rb_fiber_initialize_kw(int argc, VALUE* argv, VALUE self, int kw_splat) +{ + VALUE pool = Qnil; + VALUE blocking = Qfalse; + VALUE storage = Qundef; + + if (kw_splat != RB_NO_KEYWORDS) { + VALUE options = Qnil; + VALUE arguments[3] = {Qundef}; + + argc = rb_scan_args_kw(kw_splat, argc, argv, ":", &options); + rb_get_kwargs(options, fiber_initialize_keywords, 0, 3, arguments); + + if (!UNDEF_P(arguments[0])) { + blocking = arguments[0]; + } + + if (!UNDEF_P(arguments[1])) { + pool = arguments[1]; + } + + storage = arguments[2]; + } + + return fiber_initialize(self, rb_block_proc(), rb_fiber_pool_default(pool), RTEST(blocking), storage); +} + +/* + * call-seq: + * Fiber.new(blocking: false, storage: true) { |*args| ... } -> fiber + * + * Creates new Fiber. Initially, the fiber is not running and can be resumed + * with #resume. Arguments to the first #resume call will be passed to the + * block: + * + * f = Fiber.new do |initial| + * current = initial + * loop do + * puts "current: #{current.inspect}" + * current = Fiber.yield + * end + * end + * f.resume(100) # prints: current: 100 + * f.resume(1, 2, 3) # prints: current: [1, 2, 3] + * f.resume # prints: current: nil + * # ... and so on ... + * + * If <tt>blocking: false</tt> is passed to <tt>Fiber.new</tt>, _and_ current + * thread has a Fiber.scheduler defined, the Fiber becomes non-blocking (see + * "Non-blocking Fibers" section in class docs). + * + * If the <tt>storage</tt> is unspecified, the default is to inherit a copy of + * the storage from the current fiber. This is the same as specifying + * <tt>storage: true</tt>. + * + * Fiber[:x] = 1 + * Fiber.new do + * Fiber[:x] # => 1 + * Fiber[:x] = 2 + * end.resume + * Fiber[:x] # => 1 + * + * If the given <tt>storage</tt> is <tt>nil</tt>, this function will lazy + * initialize the internal storage, which starts as an empty hash. + * + * Fiber[:x] = "Hello World" + * Fiber.new(storage: nil) do + * Fiber[:x] # nil + * end + * + * Otherwise, the given <tt>storage</tt> is used as the new fiber's storage, + * and it must be an instance of Hash. + * + * Explicitly using <tt>storage: true</tt> is currently experimental and may + * change in the future. + */ +static VALUE +rb_fiber_initialize(int argc, VALUE* argv, VALUE self) +{ + return rb_fiber_initialize_kw(argc, argv, self, rb_keyword_given_p()); +} + +VALUE +rb_fiber_new_storage(rb_block_call_func_t func, VALUE obj, VALUE storage) +{ + return fiber_initialize(fiber_alloc(rb_cFiber), rb_proc_new(func, obj), rb_fiber_pool_default(Qnil), 0, storage); +} + +VALUE +rb_fiber_new(rb_block_call_func_t func, VALUE obj) +{ + return rb_fiber_new_storage(func, obj, Qtrue); +} + +static VALUE +rb_fiber_s_schedule_kw(int argc, VALUE* argv, int kw_splat) +{ + rb_thread_t * th = GET_THREAD(); + VALUE scheduler = th->scheduler; + VALUE fiber = Qnil; + + if (scheduler != Qnil) { + fiber = rb_fiber_scheduler_fiber(scheduler, argc, argv, kw_splat); + } + else { + rb_raise(rb_eRuntimeError, "No scheduler is available!"); + } + + return fiber; +} + +/* + * call-seq: + * Fiber.schedule { |*args| ... } -> fiber + * + * The method is <em>expected</em> to immediately run the provided block of code in a + * separate non-blocking fiber. + * + * puts "Go to sleep!" + * + * Fiber.set_scheduler(MyScheduler.new) + * + * Fiber.schedule do + * puts "Going to sleep" + * sleep(1) + * puts "I slept well" + * end + * + * puts "Wakey-wakey, sleepyhead" + * + * Assuming MyScheduler is properly implemented, this program will produce: + * + * Go to sleep! + * Going to sleep + * Wakey-wakey, sleepyhead + * ...1 sec pause here... + * I slept well + * + * ...e.g. on the first blocking operation inside the Fiber (<tt>sleep(1)</tt>), + * the control is yielded to the outside code (main fiber), and <em>at the end + * of that execution</em>, the scheduler takes care of properly resuming all the + * blocked fibers. + * + * Note that the behavior described above is how the method is <em>expected</em> + * to behave, actual behavior is up to the current scheduler's implementation of + * Fiber::Scheduler#fiber method. Ruby doesn't enforce this method to + * behave in any particular way. + * + * If the scheduler is not set, the method raises + * <tt>RuntimeError (No scheduler is available!)</tt>. + * + */ +static VALUE +rb_fiber_s_schedule(int argc, VALUE *argv, VALUE obj) +{ + return rb_fiber_s_schedule_kw(argc, argv, rb_keyword_given_p()); +} + +/* + * call-seq: + * Fiber.scheduler -> obj or nil + * + * Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler. + * Returns +nil+ if no scheduler is set (which is the default), and non-blocking fibers' + * behavior is the same as blocking. + * (see "Non-blocking fibers" section in class docs for details about the scheduler concept). + * + */ +static VALUE +rb_fiber_s_scheduler(VALUE klass) +{ + return rb_fiber_scheduler_get(); +} + +/* + * call-seq: + * Fiber.current_scheduler -> obj or nil + * + * Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler + * if and only if the current fiber is non-blocking. + * + */ +static VALUE +rb_fiber_current_scheduler(VALUE klass) +{ + return rb_fiber_scheduler_current(); +} + +/* + * call-seq: + * Fiber.set_scheduler(scheduler) -> scheduler + * + * Sets the Fiber scheduler for the current thread. If the scheduler is set, non-blocking + * fibers (created by Fiber.new with <tt>blocking: false</tt>, or by Fiber.schedule) + * call that scheduler's hook methods on potentially blocking operations, and the current + * thread will call scheduler's +close+ method on finalization (allowing the scheduler to + * properly manage all non-finished fibers). + * + * +scheduler+ can be an object of any class corresponding to Fiber::Scheduler. Its + * implementation is up to the user. + * + * See also the "Non-blocking fibers" section in class docs. + * + */ +static VALUE +rb_fiber_set_scheduler(VALUE klass, VALUE scheduler) +{ + return rb_fiber_scheduler_set(scheduler); +} + +NORETURN(static void rb_fiber_terminate(rb_fiber_t *fiber, int need_interrupt, VALUE err)); + void -rb_fiber_start(void) +rb_fiber_start(rb_fiber_t *fiber) { - rb_thread_t *th = GET_THREAD(); - rb_context_t *cont; + rb_thread_t * volatile th = fiber->cont.saved_ec.thread_ptr; + rb_proc_t *proc; - VALUE args; - int state; + enum ruby_tag_type state; + + VM_ASSERT(th->ec == GET_EC()); + VM_ASSERT(FIBER_RESUMED_P(fiber)); - GetContPtr(th->fiber, cont); - TH_PUSH_TAG(th); - if ((state = EXEC_TAG()) == 0) { - GetProcPtr(cont->saved_thread.first_proc, proc); - args = cont->value; - cont->value = Qnil; - th->errinfo = Qnil; - th->local_lfp = proc->block.lfp; - th->local_svar = Qnil; + if (fiber->blocking) { + th->blocking += 1; + } - cont->value = vm_invoke_proc(th, proc, proc->block.self, 1, &args, 0); + EC_PUSH_TAG(th->ec); + if ((state = EC_EXEC_TAG()) == TAG_NONE) { + rb_context_t *cont = &VAR_FROM_MEMORY(fiber)->cont; + int argc; + const VALUE *argv, args = cont->value; + GetProcPtr(fiber->first_proc, proc); + argv = (argc = cont->argc) > 1 ? RARRAY_CONST_PTR(args) : &args; + cont->value = Qnil; + th->ec->errinfo = Qnil; + th->ec->root_lep = rb_vm_proc_local_ep(fiber->first_proc); + th->ec->root_svar = Qfalse; + + EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil); + cont->value = rb_vm_invoke_proc(th->ec, proc, argc, argv, cont->kw_splat, VM_BLOCK_HANDLER_NONE); } - TH_POP_TAG(); + EC_POP_TAG(); + int need_interrupt = TRUE; + VALUE err = Qfalse; if (state) { - if (TAG_RAISE) { - th->thrown_errinfo = th->errinfo; - } - else { - th->thrown_errinfo = - vm_make_jump_tag_but_local_jump(state, th->errinfo); - } - RUBY_VM_SET_INTERRUPT(th); + err = th->ec->errinfo; + VM_ASSERT(FIBER_RESUMED_P(fiber)); + + if (state == TAG_RAISE) { + // noop... + } + else if (state == TAG_FATAL && err == RUBY_FATAL_FIBER_KILLED) { + need_interrupt = FALSE; + err = Qfalse; + } + else if (state == TAG_FATAL) { + rb_threadptr_pending_interrupt_enque(th, err); + } + else { + err = rb_vm_make_jump_tag_but_local_jump(state, err); + } } - rb_fiber_terminate(cont); - rb_bug("rb_fiber_start: unreachable"); + rb_fiber_terminate(fiber, need_interrupt, err); } -VALUE -rb_fiber_current() +// Set up a "root fiber", which is the fiber that every Ractor has. +void +rb_threadptr_root_fiber_setup(rb_thread_t *th) { - rb_thread_t *th = GET_THREAD(); - if (th->fiber == 0) { - /* save root */ - rb_context_t *cont = fiber_alloc(rb_cFiber); - cont->type = ROOT_FIBER_CONTEXT; - th->root_fiber = th->fiber = cont->self; + rb_fiber_t *fiber = ZALLOC(rb_fiber_t); + if (!fiber) { + rb_bug("%s", strerror(errno)); /* ... is it possible to call rb_bug here? */ } - return th->fiber; + + fiber->cont.type = FIBER_CONTEXT; + fiber->cont.saved_ec.fiber_ptr = fiber; + fiber->cont.saved_ec.serial = next_ec_serial(th->ractor); + fiber->cont.saved_ec.thread_ptr = th; + fiber->blocking = 1; + fiber->killed = 0; + fiber_status_set(fiber, FIBER_RESUMED); /* skip CREATED */ + + coroutine_initialize_main(&fiber->context); + + th->ec = &fiber->cont.saved_ec; + + cont_init_jit_cont(&fiber->cont); } -static VALUE -fiber_store(rb_context_t *next_cont) +void +rb_root_fiber_obj_setup(rb_thread_t *th) { - rb_thread_t *th = GET_THREAD(); - rb_context_t *cont; + rb_fiber_t *fiber = th->ec->fiber_ptr; + VALUE fiber_value = fiber_alloc(rb_cFiber); + DATA_PTR(fiber_value) = fiber; + fiber->cont.self = fiber_value; +} - if (th->fiber) { - GetContPtr(th->fiber, cont); - cont->saved_thread = *th; +void +rb_threadptr_root_fiber_release(rb_thread_t *th) +{ + if (th->root_fiber) { + /* ignore. A root fiber object will free th->ec */ } else { - /* create current fiber */ - cont = fiber_alloc(rb_cFiber); /* no need to allocate vm stack */ - cont->type = ROOT_FIBER_CONTEXT; - th->root_fiber = th->fiber = cont->self; + rb_execution_context_t *ec = rb_current_execution_context(false); + + VM_ASSERT(th->ec->fiber_ptr->cont.type == FIBER_CONTEXT); + VM_ASSERT(th->ec->fiber_ptr->cont.self == 0); + + if (ec && th->ec == ec) { + rb_ractor_set_current_ec(th->ractor, NULL); + } + fiber_free(th->ec->fiber_ptr); + th->ec = NULL; } +} - cont_save_machine_stack(th, cont); +void +rb_threadptr_root_fiber_terminate(rb_thread_t *th) +{ + rb_fiber_t *fiber = th->ec->fiber_ptr; - if (ruby_setjmp(cont->jmpbuf)) { - /* restored */ - GetContPtr(th->fiber, cont); - return cont->value; + fiber->status = FIBER_TERMINATED; + + // The vm_stack is `alloca`ed on the thread stack, so it's gone too: + rb_ec_clear_vm_stack(th->ec); +} + +static inline rb_fiber_t* +return_fiber(bool terminate) +{ + rb_fiber_t *fiber = fiber_current(); + rb_fiber_t *prev = fiber->prev; + + if (prev) { + fiber->prev = NULL; + prev->resuming_fiber = NULL; + return prev; } else { - return Qundef; + if (!terminate) { + rb_raise(rb_eFiberError, "attempt to yield on a not resumed fiber"); + } + + rb_thread_t *th = GET_THREAD(); + rb_fiber_t *root_fiber = th->root_fiber; + + VM_ASSERT(root_fiber != NULL); + + // search resuming fiber + for (fiber = root_fiber; fiber->resuming_fiber; fiber = fiber->resuming_fiber) { + } + + return fiber; + } +} + +VALUE +rb_fiber_current(void) +{ + return fiber_current()->cont.self; +} + +// Prepare to execute next_fiber on the given thread. +static inline void +fiber_store(rb_fiber_t *next_fiber, rb_thread_t *th) +{ + rb_fiber_t *fiber = th->ec->fiber_ptr; + + if (FIBER_CREATED_P(next_fiber)) { + fiber_prepare_stack(next_fiber); + } + + VM_ASSERT(FIBER_RESUMED_P(fiber) || FIBER_TERMINATED_P(fiber)); + VM_ASSERT(FIBER_RUNNABLE_P(next_fiber)); + + if (FIBER_RESUMED_P(fiber)) fiber_status_set(fiber, FIBER_SUSPENDED); + + fiber_status_set(next_fiber, FIBER_RESUMED); + fiber_setcontext(next_fiber, fiber); +} + +static void +fiber_check_killed(rb_fiber_t *fiber) +{ + VM_ASSERT(fiber == fiber_current()); + + if (fiber->killed) { + rb_thread_t *thread = fiber->cont.saved_ec.thread_ptr; + + thread->ec->errinfo = RUBY_FATAL_FIBER_KILLED; + EC_JUMP_TAG(thread->ec, RUBY_TAG_FATAL); } } static inline VALUE -fiber_switch(VALUE fib, int argc, VALUE *argv, int is_resume) +fiber_switch(rb_fiber_t *fiber, int argc, const VALUE *argv, int kw_splat, rb_fiber_t *resuming_fiber, bool yielding) { VALUE value; - rb_context_t *cont; + rb_context_t *cont = &fiber->cont; rb_thread_t *th = GET_THREAD(); - GetContPtr(fib, cont); + /* make sure the root_fiber object is available */ + if (th->root_fiber == NULL) { + th->root_fiber = th->ec->fiber_ptr; + } - if (cont->saved_thread.self != th->self) { - rb_raise(rb_eFiberError, "fiber called across threads"); + if (th->ec->fiber_ptr == fiber) { + /* ignore fiber context switch + * because destination fiber is the same as current fiber + */ + return make_passing_arg(argc, argv); } - else if (cont->saved_thread.trap_tag != th->trap_tag) { - rb_raise(rb_eFiberError, "fiber called across trap"); + + if (cont_thread_value(cont) != th->self) { + rb_raise(rb_eFiberError, "fiber called across threads"); } - else if (!cont->alive) { - rb_raise(rb_eFiberError, "dead fiber called"); + + if (FIBER_TERMINATED_P(fiber)) { + value = rb_exc_new2(rb_eFiberError, "dead fiber called"); + + if (!FIBER_TERMINATED_P(th->ec->fiber_ptr)) { + rb_exc_raise(value); + VM_UNREACHABLE(fiber_switch); + } + else { + /* th->ec->fiber_ptr is also dead => switch to root fiber */ + /* (this means we're being called from rb_fiber_terminate, */ + /* and the terminated fiber's return_fiber() is already dead) */ + VM_ASSERT(FIBER_SUSPENDED_P(th->root_fiber)); + + cont = &th->root_fiber->cont; + cont->argc = -1; + cont->value = value; + + fiber_setcontext(th->root_fiber, th->ec->fiber_ptr); + + VM_UNREACHABLE(fiber_switch); + } + } + + VM_ASSERT(FIBER_RUNNABLE_P(fiber)); + + rb_fiber_t *current_fiber = fiber_current(); + + VM_ASSERT(!current_fiber->resuming_fiber); + + if (resuming_fiber) { + current_fiber->resuming_fiber = resuming_fiber; + fiber->prev = fiber_current(); + fiber->yielding = 0; } - if (is_resume) { - cont->prev = rb_fiber_current(); + VM_ASSERT(!current_fiber->yielding); + if (yielding) { + current_fiber->yielding = 1; } + if (current_fiber->blocking) { + th->blocking -= 1; + } + + cont->argc = argc; + cont->kw_splat = kw_splat; cont->value = make_passing_arg(argc, argv); - if ((value = fiber_store(cont)) == Qundef) { - cont_restore_0(cont, &value); - rb_bug("rb_fiber_resume: unreachable"); + fiber_store(fiber, th); + + // We cannot free the stack until the pthread is joined: +#ifndef COROUTINE_PTHREAD_CONTEXT + if (FIBER_TERMINATED_P(fiber)) { + RB_VM_LOCKING() { + fiber_stack_release(fiber); + } } +#endif + + if (fiber_current()->blocking) { + th->blocking += 1; + } + + RUBY_VM_CHECK_INTS(th->ec); + + EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil); + + current_fiber = th->ec->fiber_ptr; + value = current_fiber->cont.value; - RUBY_VM_CHECK_INTS(); + fiber_check_killed(current_fiber); + + if (current_fiber->cont.argc == -1) { + // Fiber#raise will trigger this path. + rb_exc_raise(value); + } return value; } VALUE -rb_fiber_transfer(VALUE fib, int argc, VALUE *argv) +rb_fiber_transfer(VALUE fiber_value, int argc, const VALUE *argv) +{ + return fiber_switch(fiber_ptr(fiber_value), argc, argv, RB_NO_KEYWORDS, NULL, false); +} + +/* + * call-seq: + * fiber.blocking? -> true or false + * + * Returns +true+ if +fiber+ is blocking and +false+ otherwise. + * Fiber is non-blocking if it was created via passing <tt>blocking: false</tt> + * to Fiber.new, or via Fiber.schedule. + * + * Note that, even if the method returns +false+, the fiber behaves differently + * only if Fiber.scheduler is set in the current thread. + * + * See the "Non-blocking fibers" section in class docs for details. + * + */ +VALUE +rb_fiber_blocking_p(VALUE fiber) { - return fiber_switch(fib, argc, argv, 0); + return RBOOL(fiber_ptr(fiber)->blocking); } +static VALUE +fiber_blocking_yield(VALUE fiber_value) +{ + rb_fiber_t *fiber = fiber_ptr(fiber_value); + rb_thread_t * volatile th = fiber->cont.saved_ec.thread_ptr; + + VM_ASSERT(fiber->blocking == 0); + + // fiber->blocking is `unsigned int : 1`, so we use it as a boolean: + fiber->blocking = 1; + + // Once the fiber is blocking, and current, we increment the thread blocking state: + th->blocking += 1; + + return rb_yield(fiber_value); +} + +static VALUE +fiber_blocking_ensure(VALUE fiber_value) +{ + rb_fiber_t *fiber = fiber_ptr(fiber_value); + rb_thread_t * volatile th = fiber->cont.saved_ec.thread_ptr; + + // We are no longer blocking: + fiber->blocking = 0; + th->blocking -= 1; + + return Qnil; +} + +/* + * call-seq: + * Fiber.blocking{|fiber| ...} -> result + * + * Forces the fiber to be blocking for the duration of the block. Returns the + * result of the block. + * + * See the "Non-blocking fibers" section in class docs for details. + * + */ VALUE -rb_fiber_resume(VALUE fib, int argc, VALUE *argv) +rb_fiber_blocking(VALUE class) { - rb_context_t *cont; - GetContPtr(fib, cont); + VALUE fiber_value = rb_fiber_current(); + rb_fiber_t *fiber = fiber_ptr(fiber_value); - if (cont->prev != Qnil) { - rb_raise(rb_eFiberError, "double resume"); + // If we are already blocking, this is essentially a no-op: + if (fiber->blocking) { + return rb_yield(fiber_value); + } + else { + return rb_ensure(fiber_blocking_yield, fiber_value, fiber_blocking_ensure, fiber_value); } +} - return fiber_switch(fib, argc, argv, 1); +/* + * call-seq: + * Fiber.blocking? -> false or 1 + * + * Returns +false+ if the current fiber is non-blocking. + * Fiber is non-blocking if it was created via passing <tt>blocking: false</tt> + * to Fiber.new, or via Fiber.schedule. + * + * If the current Fiber is blocking, the method returns 1. + * Future developments may allow for situations where larger integers + * could be returned. + * + * Note that, even if the method returns +false+, Fiber behaves differently + * only if Fiber.scheduler is set in the current thread. + * + * See the "Non-blocking fibers" section in class docs for details. + * + */ +static VALUE +rb_fiber_s_blocking_p(VALUE klass) +{ + rb_thread_t *thread = GET_THREAD(); + unsigned blocking = thread->blocking; + + if (blocking == 0) + return Qfalse; + + return INT2NUM(blocking); +} + +void +rb_fiber_close(rb_fiber_t *fiber) +{ + fiber_status_set(fiber, FIBER_TERMINATED); + rb_ec_close(&fiber->cont.saved_ec); +} + +static void +rb_fiber_terminate(rb_fiber_t *fiber, int need_interrupt, VALUE error) +{ + VALUE value = fiber->cont.value; + + VM_ASSERT(FIBER_RESUMED_P(fiber)); + rb_fiber_close(fiber); + + fiber->cont.machine.stack = NULL; + fiber->cont.machine.stack_size = 0; + + rb_fiber_t *next_fiber = return_fiber(true); + + if (need_interrupt) RUBY_VM_SET_INTERRUPT(&next_fiber->cont.saved_ec); + + if (RTEST(error)) + fiber_switch(next_fiber, -1, &error, RB_NO_KEYWORDS, NULL, false); + else + fiber_switch(next_fiber, 1, &value, RB_NO_KEYWORDS, NULL, false); + ruby_stop(0); +} + +static VALUE +fiber_resume_kw(rb_fiber_t *fiber, int argc, const VALUE *argv, int kw_splat) +{ + rb_fiber_t *current_fiber = fiber_current(); + + if (argc == -1 && FIBER_CREATED_P(fiber)) { + rb_raise(rb_eFiberError, "cannot raise exception on unborn fiber"); + } + else if (FIBER_TERMINATED_P(fiber)) { + rb_raise(rb_eFiberError, "attempt to resume a terminated fiber"); + } + else if (fiber == current_fiber) { + rb_raise(rb_eFiberError, "attempt to resume the current fiber"); + } + else if (fiber->prev != NULL) { + rb_raise(rb_eFiberError, "attempt to resume a resumed fiber (double resume)"); + } + else if (fiber->resuming_fiber) { + rb_raise(rb_eFiberError, "attempt to resume a resuming fiber"); + } + else if (fiber->prev == NULL && + (!fiber->yielding && fiber->status != FIBER_CREATED)) { + rb_raise(rb_eFiberError, "attempt to resume a transferring fiber"); + } + + return fiber_switch(fiber, argc, argv, kw_splat, fiber, false); } VALUE -rb_fiber_yield(int argc, VALUE *argv) +rb_fiber_resume_kw(VALUE self, int argc, const VALUE *argv, int kw_splat) { - return rb_fiber_transfer(return_fiber(), argc, argv); + return fiber_resume_kw(fiber_ptr(self), argc, argv, kw_splat); } VALUE -rb_fiber_alive_p(VALUE fib) +rb_fiber_resume(VALUE self, int argc, const VALUE *argv) { - rb_context_t *cont; - GetContPtr(fib, cont); - return cont->alive; + return fiber_resume_kw(fiber_ptr(self), argc, argv, RB_NO_KEYWORDS); } +VALUE +rb_fiber_yield_kw(int argc, const VALUE *argv, int kw_splat) +{ + return fiber_switch(return_fiber(false), argc, argv, kw_splat, NULL, true); +} + +VALUE +rb_fiber_yield(int argc, const VALUE *argv) +{ + return fiber_switch(return_fiber(false), argc, argv, RB_NO_KEYWORDS, NULL, true); +} + +void +rb_fiber_reset_root_local_storage(rb_thread_t *th) +{ + if (th->root_fiber && th->root_fiber != th->ec->fiber_ptr) { + th->ec->local_storage = th->root_fiber->cont.saved_ec.local_storage; + } +} + +/* + * call-seq: + * fiber.alive? -> true or false + * + * Returns true if the fiber can still be resumed (or transferred + * to). After finishing execution of the fiber block this method will + * always return +false+. + */ +VALUE +rb_fiber_alive_p(VALUE fiber_value) +{ + return RBOOL(!FIBER_TERMINATED_P(fiber_ptr(fiber_value))); +} + +/* + * call-seq: + * fiber.resume(args, ...) -> obj + * + * Resumes the fiber from the point at which the last Fiber.yield was + * called, or starts running it if it is the first call to + * #resume. Arguments passed to resume will be the value of the + * Fiber.yield expression or will be passed as block parameters to + * the fiber's block if this is the first #resume. + * + * Alternatively, when resume is called it evaluates to the arguments passed + * to the next Fiber.yield statement inside the fiber's block + * or to the block value if it runs to completion without any + * Fiber.yield + */ +static VALUE +rb_fiber_m_resume(int argc, VALUE *argv, VALUE fiber) +{ + return rb_fiber_resume_kw(fiber, argc, argv, rb_keyword_given_p()); +} + +/* + * call-seq: + * fiber.backtrace -> array + * fiber.backtrace(start) -> array + * fiber.backtrace(start, count) -> array + * fiber.backtrace(start..end) -> array + * + * Returns the current execution stack of the fiber. +start+, +count+ and +end+ allow + * to select only parts of the backtrace. + * + * def level3 + * Fiber.yield + * end + * + * def level2 + * level3 + * end + * + * def level1 + * level2 + * end + * + * f = Fiber.new { level1 } + * + * # It is empty before the fiber started + * f.backtrace + * #=> [] + * + * f.resume + * + * f.backtrace + * #=> ["test.rb:2:in `yield'", "test.rb:2:in `level3'", "test.rb:6:in `level2'", "test.rb:10:in `level1'", "test.rb:13:in `block in <main>'"] + * p f.backtrace(1) # start from the item 1 + * #=> ["test.rb:2:in `level3'", "test.rb:6:in `level2'", "test.rb:10:in `level1'", "test.rb:13:in `block in <main>'"] + * p f.backtrace(2, 2) # start from item 2, take 2 + * #=> ["test.rb:6:in `level2'", "test.rb:10:in `level1'"] + * p f.backtrace(1..3) # take items from 1 to 3 + * #=> ["test.rb:2:in `level3'", "test.rb:6:in `level2'", "test.rb:10:in `level1'"] + * + * f.resume + * + * # It is nil after the fiber is finished + * f.backtrace + * #=> nil + * + */ +static VALUE +rb_fiber_backtrace(int argc, VALUE *argv, VALUE fiber) +{ + return rb_vm_backtrace(argc, argv, &fiber_ptr(fiber)->cont.saved_ec); +} + +/* + * call-seq: + * fiber.backtrace_locations -> array + * fiber.backtrace_locations(start) -> array + * fiber.backtrace_locations(start, count) -> array + * fiber.backtrace_locations(start..end) -> array + * + * Like #backtrace, but returns each line of the execution stack as a + * Thread::Backtrace::Location. Accepts the same arguments as #backtrace. + * + * f = Fiber.new { Fiber.yield } + * f.resume + * loc = f.backtrace_locations.first + * loc.label #=> "yield" + * loc.path #=> "test.rb" + * loc.lineno #=> 1 + * + * + */ static VALUE -rb_fiber_m_resume(int argc, VALUE *argv, VALUE fib) +rb_fiber_backtrace_locations(int argc, VALUE *argv, VALUE fiber) { - return rb_fiber_resume(fib, argc, argv); + return rb_vm_backtrace_locations(argc, argv, &fiber_ptr(fiber)->cont.saved_ec); } +/* + * call-seq: + * fiber.transfer(args, ...) -> obj + * + * Transfer control to another fiber, resuming it from where it last + * stopped or starting it if it was not resumed before. The calling + * fiber will be suspended much like in a call to + * Fiber.yield. + * + * The fiber which receives the transfer call treats it much like + * a resume call. Arguments passed to transfer are treated like those + * passed to resume. + * + * The two style of control passing to and from fiber (one is #resume and + * Fiber::yield, another is #transfer to and from fiber) can't be freely + * mixed. + * + * * If the Fiber's lifecycle had started with transfer, it will never + * be able to yield or be resumed control passing, only + * finish or transfer back. (It still can resume other fibers that + * are allowed to be resumed.) + * * If the Fiber's lifecycle had started with resume, it can yield + * or transfer to another Fiber, but can receive control back only + * the way compatible with the way it was given away: if it had + * transferred, it only can be transferred back, and if it had + * yielded, it only can be resumed back. After that, it again can + * transfer or yield. + * + * If those rules are broken FiberError is raised. + * + * For an individual Fiber design, yield/resume is easier to use + * (the Fiber just gives away control, it doesn't need to think + * about who the control is given to), while transfer is more flexible + * for complex cases, allowing to build arbitrary graphs of Fibers + * dependent on each other. + * + * + * Example: + * + * manager = nil # For local var to be visible inside worker block + * + * # This fiber would be started with transfer + * # It can't yield, and can't be resumed + * worker = Fiber.new { |work| + * puts "Worker: starts" + * puts "Worker: Performed #{work.inspect}, transferring back" + * # Fiber.yield # this would raise FiberError: attempt to yield on a not resumed fiber + * # manager.resume # this would raise FiberError: attempt to resume a resumed fiber (double resume) + * manager.transfer(work.capitalize) + * } + * + * # This fiber would be started with resume + * # It can yield or transfer, and can be transferred + * # back or resumed + * manager = Fiber.new { + * puts "Manager: starts" + * puts "Manager: transferring 'something' to worker" + * result = worker.transfer('something') + * puts "Manager: worker returned #{result.inspect}" + * # worker.resume # this would raise FiberError: attempt to resume a transferring fiber + * Fiber.yield # this is OK, the fiber transferred from and to, now it can yield + * puts "Manager: finished" + * } + * + * puts "Starting the manager" + * manager.resume + * puts "Resuming the manager" + * # manager.transfer # this would raise FiberError: attempt to transfer to a yielding fiber + * manager.resume + * + * <em>produces</em> + * + * Starting the manager + * Manager: starts + * Manager: transferring 'something' to worker + * Worker: starts + * Worker: Performed "something", transferring back + * Manager: worker returned "Something" + * Resuming the manager + * Manager: finished + * + */ static VALUE -rb_fiber_m_transfer(int argc, VALUE *argv, VALUE fib) +rb_fiber_m_transfer(int argc, VALUE *argv, VALUE self) { - return rb_fiber_transfer(fib, argc, argv); + return rb_fiber_transfer_kw(self, argc, argv, rb_keyword_given_p()); } static VALUE +fiber_transfer_kw(rb_fiber_t *fiber, int argc, const VALUE *argv, int kw_splat) +{ + if (fiber->resuming_fiber) { + rb_raise(rb_eFiberError, "attempt to transfer to a resuming fiber"); + } + + if (fiber->yielding) { + rb_raise(rb_eFiberError, "attempt to transfer to a yielding fiber"); + } + + return fiber_switch(fiber, argc, argv, kw_splat, NULL, false); +} + +VALUE +rb_fiber_transfer_kw(VALUE self, int argc, const VALUE *argv, int kw_splat) +{ + return fiber_transfer_kw(fiber_ptr(self), argc, argv, kw_splat); +} + +/* + * call-seq: + * Fiber.yield(args, ...) -> obj + * + * Yields control back to the context that resumed the fiber, passing + * along any arguments that were passed to it. The fiber will resume + * processing at this point when #resume is called next. + * Any arguments passed to the next #resume will be the value that + * this Fiber.yield expression evaluates to. + */ +static VALUE rb_fiber_s_yield(int argc, VALUE *argv, VALUE klass) { - return rb_fiber_yield(argc, argv); + return rb_fiber_yield_kw(argc, argv, rb_keyword_given_p()); +} + +static VALUE +fiber_raise(rb_fiber_t *fiber, VALUE exception) +{ + if (fiber == fiber_current()) { + rb_exc_raise(exception); + } + else if (fiber->resuming_fiber) { + return fiber_raise(fiber->resuming_fiber, exception); + } + else if (FIBER_SUSPENDED_P(fiber) && !fiber->yielding) { + return fiber_transfer_kw(fiber, -1, &exception, RB_NO_KEYWORDS); + } + else { + return fiber_resume_kw(fiber, -1, &exception, RB_NO_KEYWORDS); + } +} + +VALUE +rb_fiber_raise(VALUE fiber, int argc, VALUE *argv) +{ + VALUE exception = rb_exception_setup(argc, argv); + + return fiber_raise(fiber_ptr(fiber), exception); +} + +/* + * call-seq: + * raise(exception, message = exception.to_s, backtrace = nil, cause: $!) + * raise(message = nil, cause: $!) + * + * Raises an exception in the fiber at the point at which the last + * +Fiber.yield+ was called. + * + * f = Fiber.new { + * puts "Before the yield" + * Fiber.yield 1 # -- exception will be raised here + * puts "After the yield" + * } + * + * p f.resume + * f.raise "Gotcha" + * + * Output + * + * Before the first yield + * 1 + * t.rb:8:in 'Fiber.yield': Gotcha (RuntimeError) + * from t.rb:8:in 'block in <main>' + * + * If the fiber has not been started or has + * already run to completion, raises +FiberError+. If the fiber is + * yielding, it is resumed. If it is transferring, it is transferred into. + * But if it is resuming, raises +FiberError+. + * + * Raises +FiberError+ if called on a Fiber belonging to another +Thread+. + * + * See Kernel#raise for more information on arguments. + * + */ +static VALUE +rb_fiber_m_raise(int argc, VALUE *argv, VALUE self) +{ + return rb_fiber_raise(self, argc, argv); } +/* + * call-seq: + * fiber.kill -> nil + * + * Terminates the fiber by raising an uncatchable exception. + * It only terminates the given fiber and no other fiber, returning +nil+ to + * another fiber if that fiber was calling #resume or #transfer. + * + * <tt>Fiber#kill</tt> only interrupts another fiber when it is in Fiber.yield. + * If called on the current fiber then it raises that exception at the <tt>Fiber#kill</tt> call site. + * + * If the fiber has not been started, transition directly to the terminated state. + * + * If the fiber is already terminated, does nothing. + * + * Raises FiberError if called on a fiber belonging to another thread. + */ +static VALUE +rb_fiber_m_kill(VALUE self) +{ + rb_fiber_t *fiber = fiber_ptr(self); + + if (fiber->killed) return Qfalse; + fiber->killed = 1; + + if (fiber->status == FIBER_CREATED) { + fiber->status = FIBER_TERMINATED; + } + else if (fiber->status != FIBER_TERMINATED) { + if (fiber_current() == fiber) { + fiber_check_killed(fiber); + } + else { + fiber_raise(fiber_ptr(self), Qnil); + } + } + + return self; +} + +/* + * call-seq: + * Fiber.current -> fiber + * + * Returns the current fiber. If you are not running in the context of + * a fiber this method will return the root fiber. + */ static VALUE rb_fiber_s_current(VALUE klass) { return rb_fiber_current(); } +static VALUE +fiber_to_s(VALUE fiber_value) +{ + const rb_fiber_t *fiber = fiber_ptr(fiber_value); + const rb_proc_t *proc; + char status_info[0x20]; + + if (fiber->resuming_fiber) { + snprintf(status_info, 0x20, " (%s by resuming)", fiber_status_name(fiber->status)); + } + else { + snprintf(status_info, 0x20, " (%s)", fiber_status_name(fiber->status)); + } + + if (!rb_obj_is_proc(fiber->first_proc)) { + VALUE str = rb_any_to_s(fiber_value); + strlcat(status_info, ">", sizeof(status_info)); + rb_str_set_len(str, RSTRING_LEN(str)-1); + rb_str_cat_cstr(str, status_info); + return str; + } + GetProcPtr(fiber->first_proc, proc); + return rb_block_to_s(fiber_value, &proc->block, status_info); +} + +#ifdef HAVE_WORKING_FORK +void +rb_fiber_atfork(rb_thread_t *th) +{ + if (th->root_fiber) { + if (&th->root_fiber->cont.saved_ec != th->ec) { + th->root_fiber = th->ec->fiber_ptr; + } + th->root_fiber->prev = 0; + th->root_fiber->blocking = 1; + th->blocking = 1; + } +} +#endif + +#ifdef RB_EXPERIMENTAL_FIBER_POOL +static void +fiber_pool_free(void *ptr) +{ + struct fiber_pool * fiber_pool = ptr; + RUBY_FREE_ENTER("fiber_pool"); + + fiber_pool_allocation_free(fiber_pool->allocations); + SIZED_FREE(fiber_pool); + + RUBY_FREE_LEAVE("fiber_pool"); +} + +static size_t +fiber_pool_memsize(const void *ptr) +{ + const struct fiber_pool * fiber_pool = ptr; + size_t size = sizeof(*fiber_pool); + + size += fiber_pool->count * fiber_pool->size; + + return size; +} + +static const rb_data_type_t FiberPoolDataType = { + "fiber_pool", + {NULL, fiber_pool_free, fiber_pool_memsize,}, + 0, 0, RUBY_TYPED_FREE_IMMEDIATELY +}; + +static VALUE +fiber_pool_alloc(VALUE klass) +{ + struct fiber_pool *fiber_pool; + + return TypedData_Make_Struct(klass, struct fiber_pool, &FiberPoolDataType, fiber_pool); +} + +static VALUE +rb_fiber_pool_initialize(int argc, VALUE* argv, VALUE self) +{ + rb_thread_t *th = GET_THREAD(); + VALUE size = Qnil, count = Qnil, vm_stack_size = Qnil; + struct fiber_pool * fiber_pool = NULL; + + // Maybe these should be keyword arguments. + rb_scan_args(argc, argv, "03", &size, &count, &vm_stack_size); + + if (NIL_P(size)) { + size = SIZET2NUM(th->vm->default_params.fiber_machine_stack_size); + } + + if (NIL_P(count)) { + count = INT2NUM(128); + } + + if (NIL_P(vm_stack_size)) { + vm_stack_size = SIZET2NUM(th->vm->default_params.fiber_vm_stack_size); + } + + TypedData_Get_Struct(self, struct fiber_pool, &FiberPoolDataType, fiber_pool); + + fiber_pool_initialize(fiber_pool, NUM2SIZET(size), NUM2SIZET(count), 0, NUM2SIZET(vm_stack_size)); + + return self; +} +#endif + +/* + * Document-class: FiberError + * + * Raised when an invalid operation is attempted on a Fiber, in + * particular when attempting to call/resume a dead fiber, + * attempting to yield from the root fiber, or calling a fiber across + * threads. + * + * fiber = Fiber.new{} + * fiber.resume #=> nil + * fiber.resume #=> FiberError: dead fiber called + */ + +static size_t +shared_fiber_pool_minimum_count(void) +{ + size_t minimum_count = FIBER_POOL_MINIMUM_COUNT; + + const char *minimum_count_env = getenv("RUBY_SHARED_FIBER_POOL_MINIMUM_COUNT"); + if (minimum_count_env && minimum_count_env[0]) { + char *end; + unsigned long value = strtoul(minimum_count_env, &end, 10); + if (end != minimum_count_env && *end == '\0') { + minimum_count = (size_t)value; + } + else { + rb_warn("invalid RUBY_SHARED_FIBER_POOL_MINIMUM_COUNT=%s (expected a non-negative integer)", minimum_count_env); + } + } + + return minimum_count; +} + +static size_t +shared_fiber_pool_maximum_count(void) +{ + size_t maximum_count = 0; + + const char *maximum_count_env = getenv("RUBY_SHARED_FIBER_POOL_MAXIMUM_COUNT"); + if (maximum_count_env && maximum_count_env[0]) { + char *end; + unsigned long value = strtoul(maximum_count_env, &end, 10); + if (end != maximum_count_env && *end == '\0') { + maximum_count = (size_t)value; + } + else { + rb_warn("invalid RUBY_SHARED_FIBER_POOL_MAXIMUM_COUNT=%s (expected a non-negative integer)", maximum_count_env); + } + } + + return maximum_count; +} + void Init_Cont(void) { - rb_cFiber = rb_define_class("Fiber", rb_cObject); - rb_undef_alloc_func(rb_cFiber); + rb_thread_t *th = GET_THREAD(); + size_t vm_stack_size = th->vm->default_params.fiber_vm_stack_size; + size_t machine_stack_size = th->vm->default_params.fiber_machine_stack_size; + size_t stack_size = machine_stack_size + vm_stack_size; + +#ifdef _WIN32 + SYSTEM_INFO info; + GetSystemInfo(&info); + pagesize = info.dwPageSize; +#else /* not WIN32 */ + pagesize = sysconf(_SC_PAGESIZE); +#endif + SET_MACHINE_STACK_END(&th->ec->machine.stack_end); + rb_eFiberError = rb_define_class("FiberError", rb_eStandardError); - rb_define_singleton_method(rb_cFiber, "new", rb_fiber_s_new, 0); + + size_t minimum_count = shared_fiber_pool_minimum_count(); + size_t maximum_count = shared_fiber_pool_maximum_count(); + fiber_pool_initialize(&shared_fiber_pool, stack_size, minimum_count, maximum_count, vm_stack_size); + + fiber_initialize_keywords[0] = rb_intern_const("blocking"); + fiber_initialize_keywords[1] = rb_intern_const("pool"); + fiber_initialize_keywords[2] = rb_intern_const("storage"); + + const char *fiber_shared_fiber_pool_free_stacks = getenv("RUBY_SHARED_FIBER_POOL_FREE_STACKS"); + if (fiber_shared_fiber_pool_free_stacks) { + shared_fiber_pool.free_stacks = atoi(fiber_shared_fiber_pool_free_stacks); + + if (shared_fiber_pool.free_stacks < 0) { + rb_warn("Setting RUBY_SHARED_FIBER_POOL_FREE_STACKS to a negative value is not allowed."); + shared_fiber_pool.free_stacks = 0; + } + + if (shared_fiber_pool.free_stacks > 1) { + rb_warn("Setting RUBY_SHARED_FIBER_POOL_FREE_STACKS to a value greater than 1 is operating system specific, and may cause crashes."); + } + } + + rb_cFiber = rb_define_class("Fiber", rb_cObject); + rb_define_alloc_func(rb_cFiber, fiber_alloc); rb_define_singleton_method(rb_cFiber, "yield", rb_fiber_s_yield, -1); + rb_define_singleton_method(rb_cFiber, "current", rb_fiber_s_current, 0); + rb_define_singleton_method(rb_cFiber, "blocking", rb_fiber_blocking, 0); + rb_define_singleton_method(rb_cFiber, "[]", rb_fiber_storage_aref, 1); + rb_define_singleton_method(rb_cFiber, "[]=", rb_fiber_storage_aset, 2); + + rb_define_method(rb_cFiber, "initialize", rb_fiber_initialize, -1); + rb_define_method(rb_cFiber, "blocking?", rb_fiber_blocking_p, 0); + rb_define_method(rb_cFiber, "storage", rb_fiber_storage_get, 0); + rb_define_method(rb_cFiber, "storage=", rb_fiber_storage_set, 1); rb_define_method(rb_cFiber, "resume", rb_fiber_m_resume, -1); + rb_define_method(rb_cFiber, "raise", rb_fiber_m_raise, -1); + rb_define_method(rb_cFiber, "kill", rb_fiber_m_kill, 0); + rb_define_method(rb_cFiber, "backtrace", rb_fiber_backtrace, -1); + rb_define_method(rb_cFiber, "backtrace_locations", rb_fiber_backtrace_locations, -1); + rb_define_method(rb_cFiber, "to_s", fiber_to_s, 0); + rb_define_alias(rb_cFiber, "inspect", "to_s"); + rb_define_method(rb_cFiber, "transfer", rb_fiber_m_transfer, -1); + rb_define_method(rb_cFiber, "alive?", rb_fiber_alive_p, 0); + + rb_define_singleton_method(rb_cFiber, "blocking?", rb_fiber_s_blocking_p, 0); + rb_define_singleton_method(rb_cFiber, "scheduler", rb_fiber_s_scheduler, 0); + rb_define_singleton_method(rb_cFiber, "set_scheduler", rb_fiber_set_scheduler, 1); + rb_define_singleton_method(rb_cFiber, "current_scheduler", rb_fiber_current_scheduler, 0); + + rb_define_singleton_method(rb_cFiber, "schedule", rb_fiber_s_schedule, -1); + + rb_thread_t *current_thread = rb_current_thread(); + RUBY_ASSERT(CLASS_OF(current_thread->ec->fiber_ptr->cont.self) == 0); + *(VALUE *)&((struct RBasic *)current_thread->ec->fiber_ptr->cont.self)->klass = rb_cFiber; + +#ifdef RB_EXPERIMENTAL_FIBER_POOL + /* + * Document-class: Fiber::Pool + * :nodoc: experimental + */ + rb_cFiberPool = rb_define_class_under(rb_cFiber, "Pool", rb_cObject); + rb_define_alloc_func(rb_cFiberPool, fiber_pool_alloc); + rb_define_method(rb_cFiberPool, "initialize", rb_fiber_pool_initialize, -1); +#endif + + rb_provide("fiber.so"); } +RUBY_SYMBOL_EXPORT_BEGIN + void -Init_Continuation_body(void) +ruby_Init_Continuation_body(void) { rb_cContinuation = rb_define_class("Continuation", rb_cObject); rb_undef_alloc_func(rb_cContinuation); @@ -771,10 +3734,4 @@ Init_Continuation_body(void) rb_define_global_function("callcc", rb_callcc, 0); } -void -Init_Fiber_as_Coroutine(void) -{ - rb_define_method(rb_cFiber, "transfer", rb_fiber_m_transfer, -1); - rb_define_method(rb_cFiber, "alive?", rb_fiber_alive_p, 0); - rb_define_singleton_method(rb_cFiber, "current", rb_fiber_s_current, 0); -} +RUBY_SYMBOL_EXPORT_END |