diff options
Diffstat (limited to 'include/ruby/debug.h')
| -rw-r--r-- | include/ruby/debug.h | 206 |
1 files changed, 179 insertions, 27 deletions
diff --git a/include/ruby/debug.h b/include/ruby/debug.h index c88da9c43d..f7c8e6ca8d 100644 --- a/include/ruby/debug.h +++ b/include/ruby/debug.h @@ -10,6 +10,7 @@ * modify this file, provided that the conditions mentioned in the * file COPYING are met. Consult the file for details. */ +#include "ruby/internal/attr/deprecated.h" #include "ruby/internal/attr/nonnull.h" #include "ruby/internal/attr/returns_nonnull.h" #include "ruby/internal/dllexport.h" @@ -51,6 +52,25 @@ RBIMPL_ATTR_NONNULL((3)) int rb_profile_frames(int start, int limit, VALUE *buff, int *lines); /** + * Queries mysterious "frame"s of the given range. + * + * A per-thread version of rb_profile_frames(). + * Arguments and return values are the same with rb_profile_frames() with the + * exception of the first argument _thread_, which accepts the Thread to be + * profiled/queried. + * + * @param[in] thread The Ruby Thread to be profiled. + * @param[in] start Start position (0 means the topmost). + * @param[in] limit Number objects of `buff`. + * @param[out] buff Return buffer. + * @param[out] lines Return buffer. + * @return Number of objects filled into `buff`. + * @post `buff` is filled with backtrace pointers. + * @post `lines` is filled with `__LINE__` of each backtraces. + */ +int rb_profile_thread_frames(VALUE thread, int start, int limit, VALUE *buff, int *lines); + +/** * Queries the path of the passed backtrace. * * @param[in] frame What rb_profile_frames() returned. @@ -207,6 +227,17 @@ typedef VALUE (*rb_debug_inspector_func_t)(const rb_debug_inspector_t *dc, void VALUE rb_debug_inspector_open(rb_debug_inspector_func_t func, void *data); /** + * Queries the backtrace object of the context. This is as if you call + * `caller_locations` at the point of debugger. + * + * @param[in] dc A debug context. + * @return An array of `Thread::Backtrace::Location` which represents the + * current point of execution at `dc`. + + */ +VALUE rb_debug_inspector_backtrace_locations(const rb_debug_inspector_t *dc); + +/** * Queries the current receiver of the passed context's upper frame. * * @param[in] dc A debug context. @@ -250,15 +281,27 @@ VALUE rb_debug_inspector_frame_binding_get(const rb_debug_inspector_t *dc, long VALUE rb_debug_inspector_frame_iseq_get(const rb_debug_inspector_t *dc, long index); /** - * Queries the backtrace object of the context. This is as if you call - * `caller_locations` at the point of debugger. + * Queries the depth of the passed context's upper frame. * - * @param[in] dc A debug context. - * @return An array of `Thread::Backtrace::Location` which represents the - * current point of execution at `dc`. + * Note that the depth is not same as the frame index because debug_inspector + * skips some special frames but the depth counts all frames. + * + * @param[in] dc A debug context. + * @param[in] index Index of the frame from top to bottom. + * @exception rb_eArgError `index` out of range. + * @retval The depth at `index`-th frame in Integer. + */ +VALUE rb_debug_inspector_frame_depth(const rb_debug_inspector_t *dc, long index); + +// A macro to recognize `rb_debug_inspector_frame_depth()` is available or not +#define RB_DEBUG_INSPECTOR_FRAME_DEPTH(dc, index) rb_debug_inspector_frame_depth(dc, index) +/** + * Return current frmae depth. + * + * @retval The depth of the current frame in Integer. */ -VALUE rb_debug_inspector_backtrace_locations(const rb_debug_inspector_t *dc); +VALUE rb_debug_inspector_current_depth(void); /** @} */ @@ -573,48 +616,157 @@ VALUE rb_tracearg_object(rb_trace_arg_t *trace_arg); /* * Postponed Job API - * rb_postponed_job_register and rb_postponed_job_register_one are - * async-signal-safe and used via SIGPROF by the "stackprof" RubyGem + * + * This API is designed to be called from contexts where it is not safe to run Ruby + * code (e.g. because they do not hold the GVL or because GC is in progress), and + * defer a callback to run in a context where it _is_ safe. The primary intended + * users of this API is for sampling profilers like the "stackprof" gem; these work + * by scheduling the periodic delivery of a SIGPROF signal, and inside the C-level + * signal handler, deferring a job to collect a Ruby backtrace when it is next safe + * to do so. + * + * Ruby maintains a small, fixed-size postponed job table. An extension using this + * API should first call `rb_postponed_job_preregister` to register a callback + * function in this table and obtain a handle of type `rb_postponed_job_handle_t` + * to it. Subsequently, the callback can be triggered by calling + * `rb_postponed_job_trigger` with that handle, or the `data` associated with the + * callback function can be changed by calling `rb_postponed_job_preregister` again. + * + * Because the postponed job table is quite small (it only has 32 entries on most + * common systems), extensions should generally only preregister one or two `func` + * values. + * + * Historically, this API provided two functions `rb_postponed_job_register` and + * `rb_postponed_job_register_one`, which claimed to be fully async-signal-safe and + * would call back the provided `func` and `data` at an appropriate time. However, + * these functions were subject to race conditions which could cause crashes when + * racing with Ruby's internal use of them. These two functions are still present, + * but are marked as deprecated and have slightly changed semantics: + * + * * rb_postponed_job_register now works like rb_postponed_job_register_one i.e. + * `func` will only be executed at most one time each time Ruby checks for + * interrupts, no matter how many times it is registered + * * They are also called with the last `data` to be registered, not the first + * (which is how rb_postponed_job_register_one previously worked) */ + /** * Type of postponed jobs. * - * @param[in,out] arg What was passed to rb_postponed_job_register(). + * @param[in,out] arg What was passed to `rb_postponed_job_preregister` */ typedef void (*rb_postponed_job_func_t)(void *arg); /** - * Registers a postponed job. + * The type of a handle returned from `rb_postponed_job_preregister` and + * passed to `rb_postponed_job_trigger` + */ +typedef unsigned int rb_postponed_job_handle_t; +#define POSTPONED_JOB_HANDLE_INVALID ((rb_postponed_job_handle_t)UINT_MAX) + +/** + * Pre-registers a func in Ruby's postponed job preregistration table, + * returning an opaque handle which can be used to trigger the job later. Generally, + * this function will be called during the initialization routine of an extension. + * + * The returned handle can be used later to call `rb_postponed_job_trigger`. This will + * cause Ruby to call back into the registered `func` with `data` at a later time, in + * a context where the GVL is held and it is safe to perform Ruby allocations. + * + * If the given `func` was already pre-registered, this function will overwrite the + * stored data with the newly passed data, and return the same handle instance as + * was previously returned. + * + * If this function is called concurrently with the same `func`, then the stored data + * could be the value from either call (but will definitely be one of them). + * + * If this function is called to update the data concurrently with a call to + * `rb_postponed_job_trigger` on the same handle, it's undefined whether `func` will + * be called with the old data or the new data. + * + * Although the current implementation of this function is in fact async-signal-safe and + * has defined semantics when called concurrently on the same `func`, a future Ruby + * version might require that this method be called under the GVL; thus, programs which + * aim to be forward-compatible should call this method whilst holding the GVL. + * + * @param[in] flags Unused and ignored + * @param[in] func The function to be pre-registered + * @param[in] data The data to be pre-registered + * @retval POSTPONED_JOB_HANDLE_INVALID The job table is full; this registration + * did not succeed and no further registration will do so for + * the lifetime of the program. + * @retval otherwise A handle which can be passed to `rb_postponed_job_trigger` + */ +rb_postponed_job_handle_t rb_postponed_job_preregister(unsigned int flags, rb_postponed_job_func_t func, void *data); + +/** + * Triggers a pre-registered job registered with rb_postponed_job_preregister, + * scheduling it for execution the next time the Ruby VM checks for interrupts. + * The context in which the job is called in holds the GVL and is safe to perform + * Ruby allocations within (i.e. it is not during GC). + * + * This method is async-signal-safe and can be called from any thread, at any + * time, including in signal handlers. * - * There are situations when running a ruby program is not possible. For - * instance when a program is in a signal handler; for another instance when - * the GC is busy. On such situations however, there might be needs to do - * something. We cannot but defer such operations until we are 100% sure it is - * safe to execute them. This mechanism is called postponed jobs. This - * function registers a new one. The registered job would eventually gets - * executed. + * If this method is called multiple times, Ruby will coalesce this into only + * one call to the job the next time it checks for interrupts. + * + * @params[in] h A handle returned from rb_postponed_job_preregister + */ +void rb_postponed_job_trigger(rb_postponed_job_handle_t h); + +/** + * Schedules the given `func` to be called with `data` when Ruby next checks for + * interrupts. If this function is called multiple times in between Ruby checking + * for interrupts, then `func` will be called only once with the `data` value from + * the first call to this function. * - * @param[in] flags (Unused) reserved for future extensions. + * Like `rb_postponed_job_trigger`, the context in which the job is called + * holds the GVL and can allocate Ruby objects. + * + * This method essentially has the same semantics as: + * + * ``` + * rb_postponed_job_trigger(rb_postponed_job_preregister(func, data)); + * ``` + * + * @note Previous versions of Ruby promised that the (`func`, `data`) pairs would + * be executed as many times as they were registered with this function; in + * reality this was always subject to race conditions and this function no + * longer provides this guarantee. Instead, multiple calls to this function + * can be coalesced into a single execution of the passed `func`, with the + * most recent `data` registered at that time passed in. + * + * @deprecated This interface implies that arbitrarily many `func`'s can be enqueued + * over the lifetime of the program, whilst in reality the registration + * slots for postponed jobs are a finite resource. This is made clearer + * by the `rb_postponed_job_preregister` and `rb_postponed_job_trigger` + * functions, and a future version of Ruby might delete this function. + * + * @param[in] flags Unused and ignored. * @param[in] func Job body. * @param[in,out] data Passed as-is to `func`. - * @retval 0 Postponed job buffer is full. Failed. - * @retval otherwise Opaque return value. - * @post The passed job is postponed. + * @retval 0 Postponed job registration table is full. Failed. + * @retval 1 Registration succeeded. + * @post The passed job will run on the next interrupt check. */ + RBIMPL_ATTR_DEPRECATED(("use rb_postponed_job_preregister and rb_postponed_job_trigger")) int rb_postponed_job_register(unsigned int flags, rb_postponed_job_func_t func, void *data); /** - * Identical to rb_postponed_job_register_one(), except it additionally checks - * for duplicated registration. In case the passed job is already in the - * postponed job buffer this function does nothing. + * Identical to `rb_postponed_job_register` + * + * @deprecated This is deprecated for the same reason as `rb_postponed_job_register` * - * @param[in] flags (Unused) reserved for future extensions. + * @param[in] flags Unused and ignored. * @param[in] func Job body. * @param[in,out] data Passed as-is to `func`. - * @retval 0 Postponed job buffer is full. Failed. - * @retval otherwise Opaque return value. + * @retval 0 Postponed job registration table is full. Failed. + * @retval 1 Registration succeeded. + * @post The passed job will run on the next interrupt check. */ + RBIMPL_ATTR_DEPRECATED(("use rb_postponed_job_preregister and rb_postponed_job_trigger")) int rb_postponed_job_register_one(unsigned int flags, rb_postponed_job_func_t func, void *data); /** @} */ |