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/*
* Copyright (c) 1988-1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
* Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
* Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
* Copyright (c) 2007 Free Software Foundation, Inc.
* Copyright (c) 2000-2011 by Hewlett-Packard Development Company.
* Copyright (c) 2009-2022 Ivan Maidanski
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*/
/*
* Note that this defines a large number of tuning hooks, which can
* safely be ignored in nearly all cases. For normal use it suffices
* to call only GC_MALLOC and perhaps GC_REALLOC.
* For better performance, also look at GC_MALLOC_ATOMIC, and
* GC_enable_incremental. If you need an action to be performed
* immediately before an object is collected, look at GC_register_finalizer.
* Everything else is best ignored unless you encounter performance
* problems.
*/
#ifndef GC_H
#define GC_H
/* Help debug mixed up preprocessor symbols. */
#if (defined(WIN64) && !defined(_WIN64)) && defined(_MSC_VER)
#pragma message("Warning: Expecting _WIN64 for x64 targets! Notice the leading underscore!")
#endif
#include "gc_version.h"
/* Define version numbers here to allow test on build machine */
/* for cross-builds. Note that this defines the header */
/* version number, which may or may not match that of the */
/* dynamic library. GC_get_version() can be used to obtain */
/* the latter. */
#include "gc_config_macros.h"
#ifdef __cplusplus
extern "C" {
#endif
typedef void * GC_PTR; /* preserved only for backward compatibility */
/* Define word and signed word to be unsigned and signed types of the */
/* size as char* or void*. */
typedef GC_UNSIGNEDWORD GC_word;
typedef GC_SIGNEDWORD GC_signed_word;
#undef GC_SIGNEDWORD
#undef GC_UNSIGNEDWORD
#if (defined(_UINTPTR_T) || defined(_UINTPTR_T_DEFINED)) \
&& !defined(__MSYS__)
/* Note: MSYS2 might provide __uintptr_t instead of uintptr_t. */
typedef uintptr_t GC_uintptr_t;
#else
typedef GC_word GC_uintptr_t;
#endif
/* Is first pointer has a smaller address than the second one? The */
/* arguments should be of the same pointer type, e.g. of char* type. */
/* Ancient compilers might treat a pointer as a signed value, thus we */
/* need a cast to unsigned word of each compared pointer. */
#if defined(__GNUC__)
# define GC_ADDR_LT(p,q) ((p) < (q))
#else
# define GC_ADDR_LT(p,q) ((GC_word)(p) < (GC_word)(q))
#endif
/* Get the GC library version. The returned value is a constant in the */
/* form: ((version_major<<16) | (version_minor<<8) | version_micro). */
GC_API GC_VERSION_VAL_T GC_CALL GC_get_version(void);
/* Public read-only variables */
/* The supplied getter functions are preferred for new code. */
GC_API GC_ATTR_DEPRECATED GC_word GC_gc_no;
/* Counter incremented per collection. */
/* Includes empty GCs at startup. */
GC_API GC_word GC_CALL GC_get_gc_no(void);
/* GC_get_gc_no() is unsynchronized, so */
/* it requires GC_call_with_reader_lock() to */
/* avoid data race on multiprocessors. */
#ifdef GC_THREADS
/* GC is parallelized for performance on multiprocessors. Set to */
/* a non-zero value when client calls GC_start_mark_threads() */
/* directly or starts the first non-main thread, provided the */
/* collector is built with PARALLEL_MARK defined, and either */
/* GC_MARKERS (or GC_NPROCS) environment variable is set to a value */
/* bigger than 1, or multiple cores (processors) are available, or */
/* the client calls GC_set_markers_count() before GC initialization. */
/* After setting, GC_parallel value is equal to the number of marker */
/* threads minus one (i.e. the number of existing parallel marker */
/* threads excluding the initiating one). */
GC_API GC_ATTR_DEPRECATED int GC_parallel;
#endif
/* Return value of GC_parallel. Does not acquire the allocator lock. */
GC_API int GC_CALL GC_get_parallel(void);
/* Set the number of marker threads (including the initiating one) */
/* to the desired value at start-up. Zero value means the collector */
/* is to decide. If the correct non-zero value is passed, then later */
/* GC_parallel will be set to the value minus one. Has no effect if */
/* called after GC initialization. Does not itself cause creation of */
/* the marker threads. Does not use any synchronization. */
GC_API void GC_CALL GC_set_markers_count(unsigned);
/* Public R/W variables */
/* The supplied setter and getter functions are preferred for new code. */
typedef void * (GC_CALLBACK * GC_oom_func)(size_t /* bytes_requested */);
GC_API GC_ATTR_DEPRECATED GC_oom_func GC_oom_fn;
/* When there is insufficient memory to satisfy */
/* an allocation request, we return */
/* (*GC_oom_fn)(size). If it returns, it must */
/* return either NULL or a valid pointer to */
/* a previously allocated heap object. */
/* By default, this just returns NULL. */
/* GC_oom_fn must not be 0. Both the setter */
/* and the getter acquire the allocator lock */
/* (in the reader mode in case of the getter) */
/* to avoid data race. */
GC_API void GC_CALL GC_set_oom_fn(GC_oom_func) GC_ATTR_NONNULL(1);
GC_API GC_oom_func GC_CALL GC_get_oom_fn(void);
typedef void (GC_CALLBACK * GC_on_heap_resize_proc)(GC_word /* new_size */);
GC_API GC_ATTR_DEPRECATED GC_on_heap_resize_proc GC_on_heap_resize;
/* Invoked when the heap grows or shrinks. */
/* Called with the world stopped (and the */
/* allocator lock held). May be 0. */
GC_API void GC_CALL GC_set_on_heap_resize(GC_on_heap_resize_proc);
GC_API GC_on_heap_resize_proc GC_CALL GC_get_on_heap_resize(void);
/* Both the setter and the getter acquire the */
/* allocator lock (in the reader mode in case */
/* of the getter). */
typedef enum {
GC_EVENT_START /* COLLECTION */,
GC_EVENT_MARK_START,
GC_EVENT_MARK_END,
GC_EVENT_RECLAIM_START,
GC_EVENT_RECLAIM_END,
GC_EVENT_END /* COLLECTION */,
GC_EVENT_PRE_STOP_WORLD /* STOPWORLD_BEGIN */,
GC_EVENT_POST_STOP_WORLD /* STOPWORLD_END */,
GC_EVENT_PRE_START_WORLD /* STARTWORLD_BEGIN */,
GC_EVENT_POST_START_WORLD /* STARTWORLD_END */,
GC_EVENT_THREAD_SUSPENDED,
GC_EVENT_THREAD_UNSUSPENDED
} GC_EventType;
typedef void (GC_CALLBACK * GC_on_collection_event_proc)(GC_EventType);
/* Invoked to indicate progress through the */
/* collection process. Not used for thread */
/* suspend/resume notifications. Called with */
/* the allocator lock held (or, even, the world */
/* stopped). May be 0 (means no notifier). */
GC_API void GC_CALL GC_set_on_collection_event(GC_on_collection_event_proc);
GC_API GC_on_collection_event_proc GC_CALL GC_get_on_collection_event(void);
/* Both the setter and the getter acquire the */
/* allocator lock (in the reader mode in case */
/* of the getter). */
#if defined(GC_THREADS) || (defined(GC_BUILD) && defined(NN_PLATFORM_CTR))
typedef void (GC_CALLBACK * GC_on_thread_event_proc)(GC_EventType,
void * /* thread_id */);
/* Invoked when a thread is suspended or */
/* resumed during collection. Called with the */
/* allocator lock held (and the world stopped */
/* partially). May be 0 (means no notifier). */
GC_API void GC_CALL GC_set_on_thread_event(GC_on_thread_event_proc);
GC_API GC_on_thread_event_proc GC_CALL GC_get_on_thread_event(void);
/* Both the setter and the getter acquire the */
/* allocator lock (in the reader mode in case */
/* of the getter). */
#endif
GC_API GC_ATTR_DEPRECATED int GC_find_leak;
/* Set to true to turn on the leak-finding mode */
/* (do not actually garbage collect, but simply */
/* report inaccessible memory that was not */
/* deallocated with GC_FREE). Initial value */
/* is determined by FIND_LEAK macro. */
/* The value should not typically be modified */
/* after GC initialization (and, thus, it does */
/* not use or need synchronization). */
GC_API void GC_CALL GC_set_find_leak(int);
GC_API int GC_CALL GC_get_find_leak(void);
GC_API GC_ATTR_DEPRECATED int GC_all_interior_pointers;
/* Arrange for pointers to object interiors to */
/* be recognized as valid. Typically should */
/* not be changed after GC initialization (in */
/* case of calling it after the GC is */
/* initialized, the setter acquires the */
/* allocator lock. Must be only 0 or 1. The */
/* initial value depends on whether the GC is */
/* built with ALL_INTERIOR_POINTERS macro */
/* defined or not. This also affects, unless */
/* GC_get_dont_add_byte_at_end() returns */
/* a non-zero value, whether the object sizes */
/* are increased by at least a byte to allow */
/* "off the end" pointer recognition (but the */
/* size is not increased for uncollectible */
/* objects as well as for ignore-off-page */
/* objects of at least heap block size). */
GC_API void GC_CALL GC_set_all_interior_pointers(int);
GC_API int GC_CALL GC_get_all_interior_pointers(void);
GC_API GC_ATTR_DEPRECATED int GC_finalize_on_demand;
/* If nonzero, finalizers will only be run in */
/* response to an explicit GC_invoke_finalizers */
/* call. The default is determined by whether */
/* the FINALIZE_ON_DEMAND macro is defined */
/* when the collector is built. The setter and */
/* the getter are unsynchronized. */
GC_API void GC_CALL GC_set_finalize_on_demand(int);
GC_API int GC_CALL GC_get_finalize_on_demand(void);
GC_API GC_ATTR_DEPRECATED int GC_java_finalization;
/* Mark objects reachable from finalizable */
/* objects in a separate post-pass. This makes */
/* it a bit safer to use non-topologically- */
/* ordered finalization. Default value is */
/* determined by JAVA_FINALIZATION macro. */
/* Enables GC_register_finalizer_unreachable to */
/* work correctly. The setter and the getter */
/* are unsynchronized. */
GC_API void GC_CALL GC_set_java_finalization(int);
GC_API int GC_CALL GC_get_java_finalization(void);
typedef void (GC_CALLBACK * GC_finalizer_notifier_proc)(void);
GC_API GC_ATTR_DEPRECATED GC_finalizer_notifier_proc GC_finalizer_notifier;
/* Invoked by the collector when there are */
/* objects to be finalized. Invoked at most */
/* once per GC cycle. Never invoked unless */
/* GC_finalize_on_demand is set. */
/* Typically this will notify a finalization */
/* thread, which will call GC_invoke_finalizers */
/* in response. May be 0 (means no notifier). */
/* Both the setter and the getter acquire the */
/* allocator lock (in the reader mode in case */
/* of the getter). */
GC_API void GC_CALL GC_set_finalizer_notifier(GC_finalizer_notifier_proc);
GC_API GC_finalizer_notifier_proc GC_CALL GC_get_finalizer_notifier(void);
/* The functions called to report pointer checking errors. Called */
/* without the allocator lock held. The default behavior is to fail */
/* with the appropriate message which includes the pointers. The */
/* functions (variables) must not be 0. Both the setters and the */
/* getters are unsynchronized. */
typedef void (GC_CALLBACK * GC_valid_ptr_print_proc_t)(void *);
typedef void (GC_CALLBACK * GC_same_obj_print_proc_t)(void * /* p */,
void * /* q */);
GC_API GC_ATTR_DEPRECATED GC_same_obj_print_proc_t GC_same_obj_print_proc;
GC_API GC_ATTR_DEPRECATED GC_valid_ptr_print_proc_t
GC_is_valid_displacement_print_proc;
GC_API GC_ATTR_DEPRECATED GC_valid_ptr_print_proc_t GC_is_visible_print_proc;
GC_API void GC_CALL GC_set_same_obj_print_proc(GC_same_obj_print_proc_t)
GC_ATTR_NONNULL(1);
GC_API GC_same_obj_print_proc_t GC_CALL GC_get_same_obj_print_proc(void);
GC_API void GC_CALL GC_set_is_valid_displacement_print_proc(
GC_valid_ptr_print_proc_t) GC_ATTR_NONNULL(1);
GC_API GC_valid_ptr_print_proc_t GC_CALL
GC_get_is_valid_displacement_print_proc(void);
GC_API void GC_CALL GC_set_is_visible_print_proc(GC_valid_ptr_print_proc_t)
GC_ATTR_NONNULL(1);
GC_API GC_valid_ptr_print_proc_t GC_CALL GC_get_is_visible_print_proc(void);
GC_API
# ifndef GC_DONT_GC
GC_ATTR_DEPRECATED
# endif
int GC_dont_gc; /* != 0 ==> Do not collect. This overrides */
/* explicit GC_gcollect() calls as well. */
/* Used as a counter, so that nested enabling */
/* and disabling work correctly. Should */
/* normally be updated with GC_enable() and */
/* GC_disable() calls. Direct assignment to */
/* GC_dont_gc is deprecated. To check whether */
/* GC is disabled, GC_is_disabled() is */
/* preferred for new code. */
GC_API GC_ATTR_DEPRECATED int GC_dont_expand;
/* Do not expand the heap unless explicitly */
/* requested or forced to. The setter and the */
/* getter are unsynchronized. */
GC_API void GC_CALL GC_set_dont_expand(int);
GC_API int GC_CALL GC_get_dont_expand(void);
GC_API GC_ATTR_DEPRECATED int GC_use_entire_heap;
/* Causes the non-incremental collector to use the */
/* entire heap before collecting. This sometimes */
/* results in more large block fragmentation, since */
/* very large blocks will tend to get broken up */
/* during each GC cycle. It is likely to result in a */
/* larger working set, but lower collection */
/* frequencies, and hence fewer instructions executed */
/* in the collector. */
GC_API GC_ATTR_DEPRECATED int GC_full_freq;
/* Number of partial collections between full */
/* collections. Matters only if */
/* GC_is_incremental_mode(). Full collections */
/* are also triggered if the collector detects */
/* a substantial increase in the number of the */
/* in-use heap blocks. Values in the tens are */
/* now perfectly reasonable, unlike for earlier */
/* GC versions. The setter and the getter are */
/* unsynchronized, so GC_call_with_alloc_lock() */
/* (GC_call_with_reader_lock() in case of the */
/* getter) is required to avoid data race (if */
/* the value is modified after the GC is put */
/* into the multi-threaded mode). */
GC_API void GC_CALL GC_set_full_freq(int);
GC_API int GC_CALL GC_get_full_freq(void);
GC_API GC_ATTR_DEPRECATED GC_word GC_non_gc_bytes;
/* Bytes not considered candidates for */
/* collection. Used only to control scheduling */
/* of collections. Updated by */
/* GC_malloc_uncollectable and GC_free. */
/* Wizards only. The setter and the getter are */
/* unsynchronized, so GC_call_with_alloc_lock() */
/* (GC_call_with_reader_lock() in case of the */
/* getter) is required to avoid data race (if */
/* the value is modified after the GC is put */
/* into the multi-threaded mode). */
GC_API void GC_CALL GC_set_non_gc_bytes(GC_word);
GC_API GC_word GC_CALL GC_get_non_gc_bytes(void);
GC_API GC_ATTR_DEPRECATED int GC_no_dls;
/* Do not register dynamic library data */
/* segments automatically. Also, if set by the */
/* collector itself (during GC), this means */
/* that such a registration is not supported. */
/* Wizards only. Should be set only if the */
/* application explicitly registers all roots. */
/* (In some environments like Microsoft Windows */
/* and Apple's Darwin, this may also prevent */
/* registration of the main data segment as a */
/* part of the root set.) The setter and the */
/* getter are unsynchronized. */
GC_API void GC_CALL GC_set_no_dls(int);
GC_API int GC_CALL GC_get_no_dls(void);
GC_API GC_ATTR_DEPRECATED GC_word GC_free_space_divisor;
/* We try to make sure that we allocate at */
/* least N/GC_free_space_divisor bytes between */
/* collections, where N is twice the number */
/* of traced bytes, plus the number of untraced */
/* bytes (bytes in "atomic" objects), plus */
/* a rough estimate of the root set size. */
/* N approximates GC tracing work per GC. */
/* The initial value is GC_FREE_SPACE_DIVISOR. */
/* Increasing its value will use less space */
/* but more collection time. Decreasing it */
/* will appreciably decrease collection time */
/* at the expense of space. */
/* The setter and the getter are */
/* unsynchronized, so GC_call_with_alloc_lock() */
/* (GC_call_with_reader_lock() in case of the */
/* getter) is required to avoid data race (if */
/* the value is modified after the GC is put */
/* into the multi-threaded mode). In GC v7.1 */
/* and before, the setter returned the old */
/* value. */
GC_API void GC_CALL GC_set_free_space_divisor(GC_word);
GC_API GC_word GC_CALL GC_get_free_space_divisor(void);
GC_API GC_ATTR_DEPRECATED GC_word GC_max_retries;
/* The maximum number of GCs attempted before */
/* reporting out of memory after heap */
/* expansion fails. */
/* Initially 0. The setter and getter are */
/* unsynchronized, so GC_call_with_alloc_lock() */
/* (GC_call_with_reader_lock() in case of the */
/* getter) is required to avoid data race (if */
/* the value is modified after the GC is put */
/* into the multi-threaded mode). */
GC_API void GC_CALL GC_set_max_retries(GC_word);
GC_API GC_word GC_CALL GC_get_max_retries(void);
GC_API GC_ATTR_DEPRECATED char *GC_stackbottom;
/* The cold end (bottom) of user stack. */
/* May be set in the client prior to */
/* calling any GC_ routines. This */
/* avoids some overhead, and */
/* potentially some signals that can */
/* confuse debuggers. Otherwise the */
/* collector attempts to set it */
/* automatically. For multi-threaded */
/* code, this is the cold end of the */
/* stack for the primordial thread. */
/* For multi-threaded code, altering */
/* GC_stackbottom value directly after */
/* GC initialization has no effect. */
/* Portable clients should use */
/* GC_set_stackbottom(), */
/* GC_get_stack_base(), */
/* GC_call_with_gc_active() and */
/* GC_register_my_thread() instead. */
GC_API GC_ATTR_DEPRECATED int GC_dont_precollect;
/* Do not collect as part of GC */
/* initialization. Should be set only */
/* if the client wants a chance to */
/* manually initialize the root set */
/* before the first collection. */
/* Interferes with blacklisting. */
/* Wizards only. The setter and the */
/* getter are unsynchronized (and no */
/* external locking is needed since the */
/* value is accessed at the GC */
/* initialization only). */
GC_API void GC_CALL GC_set_dont_precollect(int);
GC_API int GC_CALL GC_get_dont_precollect(void);
#define GC_TIME_UNLIMITED 999999
GC_API GC_ATTR_DEPRECATED unsigned long GC_time_limit;
/* If incremental collection is enabled, we try */
/* to terminate collections after this many */
/* milliseconds (plus the amount of nanoseconds */
/* as given in the latest GC_set_time_limit_tv */
/* call, if any). Not a hard time bound. */
/* Setting this variable to GC_TIME_UNLIMITED */
/* essentially disables incremental collection */
/* (i.e. disables the "pause time exceeded" */
/* tests) while leaving generational collection */
/* enabled. The setter and the getter are */
/* unsynchronized, so GC_call_with_alloc_lock() */
/* (GC_call_with_reader_lock() in case of the */
/* getter) is required to avoid data race (if */
/* the value is modified after the GC is put */
/* into the multi-threaded mode). The setter */
/* does not update the value of the nanosecond */
/* part of the time limit (it is zero unless */
/* ever set by GC_set_time_limit_tv call). */
GC_API void GC_CALL GC_set_time_limit(unsigned long);
GC_API unsigned long GC_CALL GC_get_time_limit(void);
/* A portable type definition of time with a nanosecond precision. */
struct GC_timeval_s {
unsigned long tv_ms; /* time in milliseconds */
unsigned long tv_nsec;/* nanoseconds fraction (<1000000) */
};
/* Public procedures */
/* Set/get the time limit of the incremental collections. This is */
/* similar to GC_set_time_limit and GC_get_time_limit but the time is */
/* provided with the nanosecond precision. The value of tv_nsec part */
/* should be less than a million. If the value of tv_ms part is */
/* GC_TIME_UNLIMITED then tv_nsec is ignored. Initially, the value of */
/* tv_nsec part of the time limit is zero. The functions do not use */
/* any synchronization. Defined only if the library has been compiled */
/* without NO_CLOCK. */
GC_API void GC_CALL GC_set_time_limit_tv(struct GC_timeval_s);
GC_API struct GC_timeval_s GC_CALL GC_get_time_limit_tv(void);
/* Set/get the minimum value of the ratio of allocated bytes since GC */
/* to the amount of finalizers created since that GC (value > */
/* GC_bytes_allocd / (GC_fo_entries - last_fo_entries)) which triggers */
/* the collection instead heap expansion. The value has no effect in */
/* the GC incremental mode. The default value is 10000 unless */
/* GC_ALLOCD_BYTES_PER_FINALIZER macro with a custom value is defined */
/* to build libgc. The default value might be not the right choice for */
/* clients where e.g. most objects have a finalizer. Zero value */
/* effectively disables taking amount of finalizers in the decision */
/* whether to collect or not. The functions do not use any */
/* synchronization. */
GC_API void GC_CALL GC_set_allocd_bytes_per_finalizer(GC_word);
GC_API GC_word GC_CALL GC_get_allocd_bytes_per_finalizer(void);
/* Tell the collector to start various performance measurements. */
/* Only the total time taken by full collections is calculated, as */
/* of now. And, currently, there is no way to stop the measurements. */
/* The function does not use any synchronization. Defined only if the */
/* library has been compiled without NO_CLOCK. */
GC_API void GC_CALL GC_start_performance_measurement(void);
/* Get the total time of all full collections since the start of the */
/* performance measurements. Includes time spent in the supplementary */
/* actions like blacklists promotion, marks clearing, free lists */
/* reconstruction and objects finalization. The measurement unit is a */
/* millisecond. Note that the returned value wraps around on overflow. */
/* The function does not use any synchronization. Defined only if the */
/* library has been compiled without NO_CLOCK. */
GC_API unsigned long GC_CALL GC_get_full_gc_total_time(void);
/* Same as GC_get_full_gc_total_time but takes into account all mark */
/* phases with the world stopped and nothing else. */
GC_API unsigned long GC_CALL GC_get_stopped_mark_total_time(void);
/* Set whether the GC will allocate executable memory pages or not. */
/* A non-zero argument instructs the collector to allocate memory with */
/* the executable flag on. Must be called before the collector is */
/* initialized. May have no effect on some platforms. The default */
/* value is controlled by NO_EXECUTE_PERMISSION macro (if present then */
/* the flag is off). Portable clients should have */
/* GC_set_pages_executable(1) call (before GC_INIT) provided they are */
/* going to execute code on any of the GC-allocated memory objects. */
GC_API void GC_CALL GC_set_pages_executable(int);
/* Returns non-zero value if the GC is set to the allocate-executable */
/* mode. The mode could be changed by GC_set_pages_executable (before */
/* GC_INIT) unless the former has no effect on the platform. Does not */
/* use or need synchronization. */
GC_API int GC_CALL GC_get_pages_executable(void);
/* The setter and the getter of the minimum value returned by the */
/* internal min_bytes_allocd(). The value should not be zero; the */
/* default value is one. Not synchronized. */
GC_API void GC_CALL GC_set_min_bytes_allocd(size_t);
GC_API size_t GC_CALL GC_get_min_bytes_allocd(void);
/* Set/get the size in pages of units operated by GC_collect_a_little. */
/* The value should not be zero. Not synchronized. */
GC_API void GC_CALL GC_set_rate(int);
GC_API int GC_CALL GC_get_rate(void);
/* Set/get the maximum number of prior attempts at the world-stop */
/* marking. Not synchronized. */
GC_API void GC_CALL GC_set_max_prior_attempts(int);
GC_API int GC_CALL GC_get_max_prior_attempts(void);
/* Control whether to disable algorithm deciding if a collection should */
/* be started when we allocated enough to amortize GC. Both the setter */
/* and the getter acquire the allocator lock (in the reader mode in */
/* case of the getter) to avoid data race. */
GC_API void GC_CALL GC_set_disable_automatic_collection(int);
GC_API int GC_CALL GC_get_disable_automatic_collection(void);
/* Overrides the default handle-fork mode. Non-zero value means GC */
/* should install proper pthread_atfork handlers. Has effect only if */
/* called before GC_INIT. Clients should invoke GC_set_handle_fork */
/* with non-zero argument if going to use fork with GC functions called */
/* in the forked child. (Note that such client and atfork handlers */
/* activities are not fully POSIX-compliant.) GC_set_handle_fork */
/* instructs GC_init to setup GC fork handlers using pthread_atfork, */
/* the latter might fail (or, even, absent on some targets) causing */
/* abort at GC initialization. Issues with missing (or failed) */
/* pthread_atfork() could be avoided by invocation */
/* of GC_set_handle_fork(-1) at application start-up and surrounding */
/* each fork() with the relevant GC_atfork_prepare/parent/child calls. */
GC_API void GC_CALL GC_set_handle_fork(int);
/* Routines to handle POSIX fork() manually (no-op if handled */
/* automatically). GC_atfork_prepare should be called immediately */
/* before fork(); GC_atfork_parent should be invoked just after fork in */
/* the branch that corresponds to parent process (i.e., fork result is */
/* non-zero); GC_atfork_child is to be called immediately in the child */
/* branch (i.e., fork result is 0). Note that GC_atfork_child() call */
/* should, of course, precede GC_start_mark_threads call (if any). */
GC_API void GC_CALL GC_atfork_prepare(void);
GC_API void GC_CALL GC_atfork_parent(void);
GC_API void GC_CALL GC_atfork_child(void);
/* Initialize the collector. Portable clients should call GC_INIT() */
/* from the main program instead. */
GC_API void GC_CALL GC_init(void);
/* Return 1 (true) if the collector is initialized (or, at least, the */
/* initialization is in progress), 0 otherwise. */
GC_API int GC_CALL GC_is_init_called(void);
/* Perform the collector shutdown. (E.g. dispose critical sections on */
/* Win32 target.) A duplicate invocation is a no-op. GC_INIT should */
/* not be called after the shutdown. See also GC_win32_free_heap(). */
GC_API void GC_CALL GC_deinit(void);
/* General purpose allocation routines, with roughly malloc calling */
/* conv. The atomic versions promise that no relevant pointers are */
/* contained in the object. The non-atomic versions guarantee that the */
/* new object is cleared. GC_malloc_uncollectable allocates */
/* an object that is scanned for pointers to collectible */
/* objects, but is not itself collectible. The object is scanned even */
/* if it does not appear to be reachable. GC_malloc_uncollectable and */
/* GC_free called on the resulting object implicitly update */
/* GC_non_gc_bytes appropriately. */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_malloc(size_t /* size_in_bytes */);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_malloc_atomic(size_t /* size_in_bytes */);
GC_API GC_ATTR_MALLOC char * GC_CALL GC_strdup(const char *);
GC_API GC_ATTR_MALLOC char * GC_CALL
GC_strndup(const char *, size_t) GC_ATTR_NONNULL(1);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_malloc_uncollectable(size_t /* size_in_bytes */);
GC_API GC_ATTR_DEPRECATED void * GC_CALL GC_malloc_stubborn(size_t);
/* The routines that guarantee the requested alignment of the allocated */
/* memory object. The align argument should be non-zero and a power */
/* of two; GC_posix_memalign() also requires it to be not less than */
/* size of a pointer. Note that posix_memalign() does not change value */
/* of (*memptr) in case of failure (i.e. when the result is non-zero). */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(2) void * GC_CALL
GC_memalign(size_t /* align */, size_t /* lb */);
GC_API int GC_CALL GC_posix_memalign(void ** /* memptr */, size_t /* align */,
size_t /* lb */) GC_ATTR_NONNULL(1);
#ifndef GC_NO_VALLOC
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_valloc(size_t /* lb */);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_pvalloc(size_t /* lb */);
#endif /* !GC_NO_VALLOC */
/* Explicitly deallocate an object. Dangerous if used incorrectly. */
/* Requires a pointer to the base of an object. */
/* An object should not be enabled for finalization (and it should not */
/* contain registered disappearing links of any kind) when it is */
/* explicitly deallocated. */
/* GC_free(0) is a no-op, as required by ANSI C for free. */
GC_API void GC_CALL GC_free(void *);
/* A symbol to be intercepted by heap profilers so that they can */
/* accurately track allocations. Programs such as Valgrind massif */
/* and KDE heaptrack do tracking of allocated objects by overriding */
/* common allocator methods (e.g. malloc and free). However, because */
/* the collector does not work by calling standard allocation methods */
/* on objects that were reclaimed, we need a way to tell the profiler */
/* that an object has been freed. This function is not intended to */
/* be called by the client, it should be used for the interception */
/* purpose only. The collector calls this function internally whenever */
/* an object is freed. Defined only if the library has been compiled */
/* with VALGRIND_TRACKING. */
GC_API void GC_CALLBACK GC_free_profiler_hook(void *);
/* The "stubborn" objects allocation is not supported anymore. Exists */
/* only for the backward compatibility. */
#define GC_MALLOC_STUBBORN(sz) GC_MALLOC(sz)
#define GC_NEW_STUBBORN(t) GC_NEW(t)
#define GC_CHANGE_STUBBORN(p) GC_change_stubborn(p)
GC_API GC_ATTR_DEPRECATED void GC_CALL GC_change_stubborn(const void *);
/* Inform the collector that the object has been changed. */
/* Only non-NULL pointer stores into the object are considered to be */
/* changes. Matters only if the incremental collection is enabled in */
/* the manual VDB mode (otherwise the function does nothing). */
/* Should be followed typically by GC_reachable_here called for each */
/* of the stored pointers. */
GC_API void GC_CALL GC_end_stubborn_change(const void *) GC_ATTR_NONNULL(1);
/* Return a pointer to the base (lowest address) of an object given */
/* a pointer to a location within the object. */
/* I.e., map an interior pointer to the corresponding base pointer. */
/* Note that with debugging allocation, this returns a pointer to the */
/* actual base of the object, i.e. the debug information, not to */
/* the base of the user object. */
/* Return 0 if displaced_pointer doesn't point to within a valid */
/* object. */
/* Note that a deallocated object in the garbage collected heap */
/* may be considered valid, even if it has been deallocated with */
/* GC_free. */
GC_API void * GC_CALL GC_base(void * /* displaced_pointer */);
/* Return 1 (true) if the argument points to somewhere in the GC heap, */
/* 0 otherwise. Primary use is as a fast alternative to GC_base() to */
/* check whether the given object is allocated by the collector or not. */
/* It is assumed that the collector is already initialized. */
GC_API int GC_CALL GC_is_heap_ptr(const void *);
/* Given a pointer to the base of an object, return its size in bytes. */
/* (For small objects this also happens to work from interior pointers, */
/* but that should not be relied upon.) The returned size may be */
/* slightly larger than what was originally requested. The argument */
/* may be NULL (causing 0 to be returned). */
GC_API size_t GC_CALL GC_size(const void * /* obj_addr */);
/* For compatibility with C library. This is occasionally faster than */
/* a malloc followed by a bcopy. But if you rely on that, either here */
/* or with the standard C library, your code is broken. In my */
/* opinion, it shouldn't have been invented, but now we're stuck. -HB */
/* The resulting object has the same kind as the original. */
/* It is an error to have changes enabled for the original object. */
/* It does not change the content of the object from its beginning to */
/* the minimum of old size and new_size_in_bytes; the content above in */
/* case of object size growth is initialized to zero (not guaranteed */
/* for atomic object type). The function follows ANSI conventions for */
/* NULL old_object (i.e., equivalent to GC_malloc regardless of new */
/* size). If new size is zero (and old_object is non-NULL) then the */
/* call is equivalent to GC_free (and NULL is returned). If old_object */
/* is non-NULL, it must have been returned by an earlier call to */
/* GC_malloc* or GC_realloc. In case of the allocation failure, the */
/* memory pointed by old_object is untouched (and not freed). */
/* If the returned pointer is not the same as old_object and both of */
/* them are non-NULL then old_object is freed. Returns either NULL (in */
/* case of the allocation failure or zero new size) or pointer to the */
/* allocated memory. */
GC_API void * GC_CALL GC_realloc(void * /* old_object */,
size_t /* new_size_in_bytes */)
/* 'realloc' attr */ GC_ATTR_ALLOC_SIZE(2);
/* Increase the heap size explicitly. Includes a GC_init() call. */
/* Returns 0 on failure, 1 on success. */
GC_API int GC_CALL GC_expand_hp(size_t /* number_of_bytes */);
/* Limit the heap size to n bytes. Useful when you're debugging, */
/* especially on systems that don't handle running out of memory well. */
/* n == 0 ==> unbounded. This is the default. This setter function is */
/* unsynchronized (so it might require GC_call_with_alloc_lock to avoid */
/* data race). */
GC_API void GC_CALL GC_set_max_heap_size(GC_word /* n */);
/* Inform the collector that a certain section of statically allocated */
/* memory contains no pointers to garbage collected memory. Thus it */
/* need not be scanned. This is sometimes important if the application */
/* maps large read/write files into the address space, which could be */
/* mistaken for dynamic library data segments on some systems. */
/* Both section start and end are not needed to be pointer-aligned. */
GC_API void GC_CALL GC_exclude_static_roots(void * /* low_address */,
void * /* high_address_plus_1 */);
/* Clear the number of entries in the exclusion table. Wizards only. */
/* Should be called typically with the allocator lock held. */
GC_API void GC_CALL GC_clear_exclusion_table(void);
/* Clear the set of root segments. Wizards only. */
GC_API void GC_CALL GC_clear_roots(void);
/* Add a root segment. Wizards only. */
/* May merge adjacent or overlapping segments if appropriate. */
/* Both segment start and end are not needed to be pointer-aligned. */
/* low_address must not be greater than high_address_plus_1. */
GC_API void GC_CALL GC_add_roots(void * /* low_address */,
void * /* high_address_plus_1 */);
/* Remove root segments located fully in the region. Wizards only. */
GC_API void GC_CALL GC_remove_roots(void * /* low_address */,
void * /* high_address_plus_1 */);
/* Add a displacement to the set of those considered valid by the */
/* collector. GC_register_displacement(n) means that if p was returned */
/* by GC_malloc, then (char *)p + n will be considered to be a valid */
/* pointer to p. N must be small and less than the size of p. */
/* (All pointers to the interior of objects from the stack are */
/* considered valid in any case. This applies to heap objects and */
/* static data.) */
/* Preferably, this should be called before any other GC procedures. */
/* Calling it later adds to the probability of excess memory */
/* retention. */
/* This is a no-op if the collector has recognition of */
/* arbitrary interior pointers enabled, which is now the default. */
GC_API void GC_CALL GC_register_displacement(size_t /* n */);
/* The following version should be used if any debugging allocation is */
/* being done. */
GC_API void GC_CALL GC_debug_register_displacement(size_t /* n */);
/* Explicitly trigger a full, world-stop collection. */
GC_API void GC_CALL GC_gcollect(void);
/* Same as above but ignores the default stop_func setting and tries to */
/* unmap as much memory as possible (regardless of the corresponding */
/* switch setting). The recommended usage: on receiving a system */
/* low-memory event; before retrying a system call failed because of */
/* the system is running out of resources. */
GC_API void GC_CALL GC_gcollect_and_unmap(void);
/* Trigger a full world-stopped collection. Abort the collection if */
/* and when stop_func returns a nonzero value. Stop_func will be */
/* called frequently, and should be reasonably fast. (stop_func is */
/* called with the allocator lock held and the world might be stopped; */
/* it's not allowed for stop_func to manipulate pointers to the garbage */
/* collected heap or call most of GC functions.) This works even */
/* if virtual dirty bits, and hence incremental collection is not */
/* available for this architecture. Collections can be aborted faster */
/* than normal pause times for incremental collection. However, */
/* aborted collections do no useful work; the next collection needs */
/* to start from the beginning. stop_func must not be 0. */
/* GC_try_to_collect() returns 0 if the collection was aborted (or the */
/* collections are disabled), 1 if it succeeded. */
typedef int (GC_CALLBACK * GC_stop_func)(void);
GC_API int GC_CALL GC_try_to_collect(GC_stop_func /* stop_func */)
GC_ATTR_NONNULL(1);
/* Set and get the default stop_func. The default stop_func is used by */
/* GC_gcollect() and by implicitly triggered collections (except for */
/* the case when handling out of memory). Must not be 0. Both the */
/* setter and the getter acquire the allocator lock (in the reader mode */
/* in case of the getter) to avoid data race. */
GC_API void GC_CALL GC_set_stop_func(GC_stop_func /* stop_func */)
GC_ATTR_NONNULL(1);
GC_API GC_stop_func GC_CALL GC_get_stop_func(void);
/* Return the number of bytes in the heap. Excludes collector private */
/* data structures. Excludes the unmapped memory (returned to the OS). */
/* Includes empty blocks and fragmentation loss. Includes some pages */
/* that were allocated but never written. This is an unsynchronized */
/* getter, so it should be called typically with the allocator lock */
/* held, at least in the reader mode, to avoid data race on */
/* multiprocessors (the alternative way is to use GC_get_prof_stats or */
/* GC_get_heap_usage_safe API calls instead). */
/* This getter remains lock-free (unsynchronized) for compatibility */
/* reason since some existing clients call it from a GC callback */
/* holding the allocator lock. (This API function and the following */
/* four ones below were made thread-safe in GC v7.2alpha1 and */
/* reverted back in v7.2alpha7 for the reason described.) */
GC_API size_t GC_CALL GC_get_heap_size(void);
/* Return a lower bound on the number of free bytes in the heap */
/* (excluding the unmapped memory space). This is an unsynchronized */
/* getter (see GC_get_heap_size comment regarding thread-safety). */
GC_API size_t GC_CALL GC_get_free_bytes(void);
/* Return the size (in bytes) of the unmapped memory (which is returned */
/* to the OS but could be remapped back by the collector later unless */
/* the OS runs out of system/virtual memory). This is an unsynchronized */
/* getter (see GC_get_heap_size comment regarding thread-safety). */
GC_API size_t GC_CALL GC_get_unmapped_bytes(void);
/* Return the number of bytes allocated since the last collection. */
/* This is an unsynchronized getter (see GC_get_heap_size comment */
/* regarding thread-safety). */
GC_API size_t GC_CALL GC_get_bytes_since_gc(void);
/* Return the number of explicitly deallocated bytes of memory since */
/* the recent collection. This is an unsynchronized getter. */
GC_API size_t GC_CALL GC_get_expl_freed_bytes_since_gc(void);
/* Return the total number of bytes allocated in this process. */
/* Never decreases, except due to wrapping. This is an unsynchronized */
/* getter (see GC_get_heap_size comment regarding thread-safety). */
GC_API size_t GC_CALL GC_get_total_bytes(void);
/* Return the total number of bytes obtained from OS. Includes the */
/* unmapped memory. Never decreases. It is an unsynchronized getter. */
GC_API size_t GC_CALL GC_get_obtained_from_os_bytes(void);
/* Return the heap usage information. This is a thread-safe (atomic) */
/* alternative for the five above getters. (This function acquires */
/* the allocator lock in the reader mode, thus preventing data race and */
/* returning the consistent result.) Passing NULL pointer is allowed */
/* for any argument. Returned (filled in) values are of word type. */
GC_API void GC_CALL GC_get_heap_usage_safe(GC_word * /* pheap_size */,
GC_word * /* pfree_bytes */,
GC_word * /* punmapped_bytes */,
GC_word * /* pbytes_since_gc */,
GC_word * /* ptotal_bytes */);
/* Structure used to query GC statistics (profiling information). */
/* More fields could be added in the future. To preserve compatibility */
/* new fields should be added only to the end, and no deprecated fields */
/* should be removed from. */
struct GC_prof_stats_s {
GC_word heapsize_full;
/* Heap size in bytes (including the area unmapped to OS). */
/* Same as GC_get_heap_size() + GC_get_unmapped_bytes(). */
GC_word free_bytes_full;
/* Total bytes contained in free and unmapped blocks. */
/* Same as GC_get_free_bytes() + GC_get_unmapped_bytes(). */
GC_word unmapped_bytes;
/* Amount of memory unmapped to OS. Same as the value */
/* returned by GC_get_unmapped_bytes(). */
GC_word bytes_allocd_since_gc;
/* Number of bytes allocated since the recent collection. */
/* Same as returned by GC_get_bytes_since_gc(). */
GC_word allocd_bytes_before_gc;
/* Number of bytes allocated before the recent garbage */
/* collection. The value may wrap. Same as the result of */
/* GC_get_total_bytes() - GC_get_bytes_since_gc(). */
GC_word non_gc_bytes;
/* Number of bytes not considered candidates for garbage */
/* collection. Same as returned by GC_get_non_gc_bytes(). */
GC_word gc_no;
/* Garbage collection cycle number. The value may wrap */
/* (and could be -1). Same as returned by GC_get_gc_no(). */
GC_word markers_m1;
/* Number of marker threads (excluding the initiating one). */
/* Same as returned by GC_get_parallel (or 0 if the */
/* collector is single-threaded). */
GC_word bytes_reclaimed_since_gc;
/* Approximate number of reclaimed bytes after recent GC. */
GC_word reclaimed_bytes_before_gc;
/* Approximate number of bytes reclaimed before the recent */
/* garbage collection. The value may wrap. */
GC_word expl_freed_bytes_since_gc;
/* Number of bytes freed explicitly since the recent GC. */
/* Same as returned by GC_get_expl_freed_bytes_since_gc(). */
GC_word obtained_from_os_bytes;
/* Total amount of memory obtained from OS, in bytes. */
};
/* Atomically get GC statistics (various global counters). Clients */
/* should pass the size of the buffer (of GC_prof_stats_s type) to fill */
/* in the values - this is for interoperability between different GC */
/* versions, an old client could have fewer fields, and vice versa, */
/* client could use newer gc.h (with more entries declared in the */
/* structure) than that of the linked libgc binary; in the latter case, */
/* unsupported (unknown) fields are filled in with -1. Return the size */
/* (in bytes) of the filled in part of the structure (excluding all */
/* unknown fields, if any). */
GC_API size_t GC_CALL GC_get_prof_stats(struct GC_prof_stats_s *,
size_t /* stats_sz */);
#ifdef GC_THREADS
/* Same as above but unsynchronized (i.e., not holding the allocator */
/* lock). Clients should call it using GC_call_with_reader_lock() to */
/* avoid data race on multiprocessors. */
GC_API size_t GC_CALL GC_get_prof_stats_unsafe(struct GC_prof_stats_s *,
size_t /* stats_sz */);
#endif
/* Get the element value (converted to bytes) at a given index of */
/* size_map table which provides requested-to-actual allocation size */
/* mapping. Assumes the collector is initialized. Returns -1 if the */
/* index is out of size_map table bounds. Does not use synchronization, */
/* thus clients should call it using GC_call_with_reader_lock() */
/* typically to avoid data race on multiprocessors. */
GC_API size_t GC_CALL GC_get_size_map_at(int i);
/* Return the total memory use (in bytes) by all allocated blocks. */
/* The result is equal to GC_get_heap_size() - GC_get_free_bytes(). */
/* Acquires the allocator lock in the reader mode. */
GC_API GC_word GC_CALL GC_get_memory_use(void);
/* Disable garbage collection. Even GC_gcollect calls will be */
/* ineffective. */
GC_API void GC_CALL GC_disable(void);
/* Return 1 (true) if the garbage collection is disabled (i.e., the */
/* value of GC_dont_gc is non-zero), 0 otherwise. Does not acquire */
/* the allocator lock. */
GC_API int GC_CALL GC_is_disabled(void);
/* Try to re-enable garbage collection. GC_disable() and GC_enable() */
/* calls nest. Garbage collection is enabled if the number of calls to */
/* both functions is equal. */
GC_API void GC_CALL GC_enable(void);
/* Select whether to use the manual VDB mode for the incremental */
/* collection. Has no effect if called after enabling the incremental */
/* collection. The default value is off unless the collector is */
/* compiled with MANUAL_VDB defined. The manual VDB mode should be */
/* used only if the client has the appropriate GC_END_STUBBORN_CHANGE */
/* and GC_reachable_here (or, alternatively, GC_PTR_STORE_AND_DIRTY) */
/* calls (to ensure proper write barriers). The setter and the getter */
/* are not synchronized. */
GC_API void GC_CALL GC_set_manual_vdb_allowed(int);
GC_API int GC_CALL GC_get_manual_vdb_allowed(void);
/* The constants to represent available VDB techniques. */
#define GC_VDB_NONE 0 /* means the incremental mode is unsupported */
#define GC_VDB_MPROTECT 0x1
#define GC_VDB_MANUAL 0x2 /* means GC_set_manual_vdb_allowed(1) has effect */
#define GC_VDB_DEFAULT 0x4 /* means no other technique is usable */
#define GC_VDB_GWW 0x8
#define GC_VDB_PCR 0x10
#define GC_VDB_PROC 0x20
#define GC_VDB_SOFT 0x40
/* Get the list of available virtual dirty bits (VDB) techniques. */
/* The returned value is a constant one, either GC_VDB_NONE, or one or */
/* more of the above GC_VDB_* constants, or'ed together. May be called */
/* before the collector is initialized. */
GC_API unsigned GC_CALL GC_get_supported_vdbs(void);
/* Enable incremental/generational collection. Not advisable unless */
/* dirty bits are available or most heap objects are pointer-free */
/* (atomic) or immutable. Don't use in leak finding mode. Ignored if */
/* GC_dont_gc is non-zero. Only the generational piece of this is */
/* functional if GC_time_limit is set to GC_TIME_UNLIMITED. Causes */
/* thread-local variant of GC_gcj_malloc() to revert to locked */
/* allocation. Must be called before any such GC_gcj_malloc() calls. */
/* For best performance, should be called as early as possible. */
/* On some platforms, calling it later may have adverse effects. */
/* Safe to call before GC_INIT(). Includes a GC_init() call. */
GC_API void GC_CALL GC_enable_incremental(void);
/* Return 1 (true) if the incremental mode is on, 0 otherwise. */
/* Does not acquire the allocator lock. */
GC_API int GC_CALL GC_is_incremental_mode(void);
/* An extended version of GC_is_incremental_mode() to return one of */
/* GC_VDB_* constants designating which VDB technique is used exactly. */
/* Does not acquire the allocator lock. */
GC_API unsigned GC_CALL GC_get_actual_vdb(void);
#define GC_PROTECTS_POINTER_HEAP 1 /* May protect non-atomic objects. */
#define GC_PROTECTS_PTRFREE_HEAP 2
#define GC_PROTECTS_STATIC_DATA 4 /* Currently never. */
#define GC_PROTECTS_STACK 8 /* Probably impractical. */
#define GC_PROTECTS_NONE 0
/* Does incremental mode write-protect pages? Returns zero or */
/* more of the above GC_PROTECTS_*, or'ed together. */
/* The collector is assumed to be initialized before this call. */
/* The result is not affected by GC_set_manual_vdb_allowed(). */
/* Call of GC_enable_incremental() may change the result to */
/* GC_PROTECTS_NONE if some implementation is chosen at runtime */
/* not needing to write-protect the pages. */
GC_API int GC_CALL GC_incremental_protection_needs(void);
/* Force start of incremental collection. Acquires the allocator lock. */
/* No-op unless GC incremental mode is on. */
GC_API void GC_CALL GC_start_incremental_collection(void);
/* Perform some garbage collection work, if appropriate. */
/* Return 0 if there is no more work to be done (including the */
/* case when garbage collection is not appropriate). */
/* Typically performs an amount of work corresponding roughly */
/* to marking from one page. May do more work if further */
/* progress requires it, e.g. if incremental collection is */
/* disabled. It is reasonable to call this in a wait loop */
/* until it returns 0. If GC is disabled but the incremental */
/* collection is already ongoing, then perform marking anyway */
/* but not stopping the world (and without the reclaim phase). */
GC_API int GC_CALL GC_collect_a_little(void);
/* Allocate an object of size lb bytes. The client guarantees that as */
/* long as the object is live, it will be referenced by a pointer that */
/* points to somewhere within the first GC heap block (hblk) of the */
/* object. (This should normally be declared volatile to prevent the */
/* compiler from invalidating this assertion.) This routine is only */
/* useful if a large array is being allocated. It reduces the chance */
/* of accidentally retaining such an array as a result of scanning an */
/* integer that happens to be an address inside the array. (Actually, */
/* it reduces the chance of the allocator not finding space for such */
/* an array, since it will try hard to avoid introducing such a false */
/* reference.) On a SunOS 4.X or Windows system this is recommended */
/* for arrays likely to be larger than 100 KB or so. For other systems,*/
/* or if the collector is not configured to recognize all interior */
/* pointers, the threshold is normally much higher. */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_malloc_ignore_off_page(size_t /* lb */);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_malloc_atomic_ignore_off_page(size_t /* lb */);
#if (defined(GC_CAN_SAVE_CALL_STACKS) || defined(GC_ADD_CALLER)) \
&& !defined(GC_RETURN_ADDR_T_DEFINED)
/* A type to hold a function return address (pointer). Never used */
/* for calling a function. */
# if defined(__GNUC__)
/* Define it as a data (object) pointer type to avoid the compiler */
/* complain that ISO C forbids conversion between object and */
/* function pointer types. */
typedef void *GC_return_addr_t;
# else
typedef void (*GC_return_addr_t)(void);
# endif
# define GC_RETURN_ADDR_T_DEFINED
#endif /* GC_CAN_SAVE_CALL_STACKS || GC_ADD_CALLER */
#ifdef GC_ADD_CALLER
# define GC_EXTRAS GC_RETURN_ADDR, __FILE__, __LINE__
# define GC_EXTRA_PARAMS GC_return_addr_t ra, const char * s, int i
#else
# define GC_EXTRAS __FILE__, __LINE__
# define GC_EXTRA_PARAMS const char * s, int i
#endif
/* The following is only defined if the library has been suitably */
/* compiled: */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_malloc_atomic_uncollectable(size_t /* size_in_bytes */);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_debug_malloc_atomic_uncollectable(size_t, GC_EXTRA_PARAMS);
/* Debugging (annotated) allocation. GC_gcollect will check */
/* objects allocated in this way for overwrites, etc. */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_debug_malloc(size_t /* size_in_bytes */, GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_debug_malloc_atomic(size_t /* size_in_bytes */, GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC char * GC_CALL
GC_debug_strdup(const char *, GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC char * GC_CALL
GC_debug_strndup(const char *, size_t, GC_EXTRA_PARAMS)
GC_ATTR_NONNULL(1);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_debug_malloc_uncollectable(size_t /* size_in_bytes */,
GC_EXTRA_PARAMS);
GC_API GC_ATTR_DEPRECATED void * GC_CALL
GC_debug_malloc_stubborn(size_t /* size_in_bytes */, GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_debug_malloc_ignore_off_page(size_t /* size_in_bytes */,
GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_debug_malloc_atomic_ignore_off_page(size_t /* size_in_bytes */,
GC_EXTRA_PARAMS);
GC_API void GC_CALL GC_debug_free(void *);
GC_API void * GC_CALL GC_debug_realloc(void * /* old_object */,
size_t /* new_size_in_bytes */, GC_EXTRA_PARAMS)
/* 'realloc' attr */ GC_ATTR_ALLOC_SIZE(2);
GC_API GC_ATTR_DEPRECATED void GC_CALL GC_debug_change_stubborn(const void *);
GC_API void GC_CALL GC_debug_end_stubborn_change(const void *)
GC_ATTR_NONNULL(1);
/* Routines that allocate objects with debug information (like the */
/* above), but just fill in dummy file and line number information. */
/* Thus they can serve as drop-in malloc/realloc replacements. This */
/* can be useful for two reasons: */
/* 1) It allows the collector to be built with DBG_HDRS_ALL defined */
/* even if some allocation calls come from 3rd party libraries */
/* that can't be recompiled. */
/* 2) On some platforms, the file and line information is redundant, */
/* since it can be reconstructed from a stack trace. On such */
/* platforms it may be more convenient not to recompile, e.g. for */
/* leak detection. This can be accomplished by instructing the */
/* linker to replace malloc/realloc with these. */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void * GC_CALL
GC_debug_malloc_replacement(size_t /* size_in_bytes */);
GC_API /* 'realloc' attr */ GC_ATTR_ALLOC_SIZE(2) void * GC_CALL
GC_debug_realloc_replacement(void * /* object_addr */,
size_t /* size_in_bytes */);
#ifdef __cplusplus
# define GC_CAST_AWAY_CONST_PVOID(p) \
reinterpret_cast</* no const */ void *>(reinterpret_cast<GC_uintptr_t>(p))
#else
# define GC_CAST_AWAY_CONST_PVOID(p) ((/* no const */ void *)(GC_uintptr_t)(p))
#endif
/* Convenient macros for disappearing links registration working both */
/* for debug and non-debug allocated objects, and accepting interior */
/* pointers to object. */
#define GC_GENERAL_REGISTER_DISAPPEARING_LINK_SAFE(link, obj) \
GC_general_register_disappearing_link(link, \
GC_base(GC_CAST_AWAY_CONST_PVOID(obj)))
#define GC_REGISTER_LONG_LINK_SAFE(link, obj) \
GC_register_long_link(link, GC_base(GC_CAST_AWAY_CONST_PVOID(obj)))
#ifdef GC_DEBUG_REPLACEMENT
# define GC_MALLOC(sz) GC_debug_malloc_replacement(sz)
# define GC_REALLOC(old, sz) GC_debug_realloc_replacement(old, sz)
#elif defined(GC_DEBUG)
# define GC_MALLOC(sz) GC_debug_malloc(sz, GC_EXTRAS)
# define GC_REALLOC(old, sz) GC_debug_realloc(old, sz, GC_EXTRAS)
#else
# define GC_MALLOC(sz) GC_malloc(sz)
# define GC_REALLOC(old, sz) GC_realloc(old, sz)
#endif /* !GC_DEBUG_REPLACEMENT && !GC_DEBUG */
#ifdef GC_DEBUG
# define GC_MALLOC_ATOMIC(sz) GC_debug_malloc_atomic(sz, GC_EXTRAS)
# define GC_STRDUP(s) GC_debug_strdup(s, GC_EXTRAS)
# define GC_STRNDUP(s, sz) GC_debug_strndup(s, sz, GC_EXTRAS)
# define GC_MALLOC_ATOMIC_UNCOLLECTABLE(sz) \
GC_debug_malloc_atomic_uncollectable(sz, GC_EXTRAS)
# define GC_MALLOC_UNCOLLECTABLE(sz) \
GC_debug_malloc_uncollectable(sz, GC_EXTRAS)
# define GC_MALLOC_IGNORE_OFF_PAGE(sz) \
GC_debug_malloc_ignore_off_page(sz, GC_EXTRAS)
# define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \
GC_debug_malloc_atomic_ignore_off_page(sz, GC_EXTRAS)
# define GC_FREE(p) GC_debug_free(p)
# define GC_REGISTER_FINALIZER(p, f, d, of, od) \
GC_debug_register_finalizer(p, f, d, of, od)
# define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
GC_debug_register_finalizer_ignore_self(p, f, d, of, od)
# define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
GC_debug_register_finalizer_no_order(p, f, d, of, od)
# define GC_REGISTER_FINALIZER_UNREACHABLE(p, f, d, of, od) \
GC_debug_register_finalizer_unreachable(p, f, d, of, od)
# define GC_TOGGLEREF_ADD(p, is_strong) GC_debug_toggleref_add(p, is_strong)
# define GC_END_STUBBORN_CHANGE(p) GC_debug_end_stubborn_change(p)
# define GC_PTR_STORE_AND_DIRTY(p, q) GC_debug_ptr_store_and_dirty(p, q)
# define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
GC_GENERAL_REGISTER_DISAPPEARING_LINK_SAFE(link, obj)
# define GC_REGISTER_LONG_LINK(link, obj) \
GC_REGISTER_LONG_LINK_SAFE(link, obj)
# define GC_REGISTER_DISPLACEMENT(n) GC_debug_register_displacement(n)
#else
# define GC_MALLOC_ATOMIC(sz) GC_malloc_atomic(sz)
# define GC_STRDUP(s) GC_strdup(s)
# define GC_STRNDUP(s, sz) GC_strndup(s, sz)
# define GC_MALLOC_ATOMIC_UNCOLLECTABLE(sz) GC_malloc_atomic_uncollectable(sz)
# define GC_MALLOC_UNCOLLECTABLE(sz) GC_malloc_uncollectable(sz)
# define GC_MALLOC_IGNORE_OFF_PAGE(sz) \
GC_malloc_ignore_off_page(sz)
# define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \
GC_malloc_atomic_ignore_off_page(sz)
# define GC_FREE(p) GC_free(p)
# define GC_REGISTER_FINALIZER(p, f, d, of, od) \
GC_register_finalizer(p, f, d, of, od)
# define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
GC_register_finalizer_ignore_self(p, f, d, of, od)
# define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
GC_register_finalizer_no_order(p, f, d, of, od)
# define GC_REGISTER_FINALIZER_UNREACHABLE(p, f, d, of, od) \
GC_register_finalizer_unreachable(p, f, d, of, od)
# define GC_TOGGLEREF_ADD(p, is_strong) GC_toggleref_add(p, is_strong)
# define GC_END_STUBBORN_CHANGE(p) GC_end_stubborn_change(p)
# define GC_PTR_STORE_AND_DIRTY(p, q) GC_ptr_store_and_dirty(p, q)
# define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
GC_general_register_disappearing_link(link, obj)
# define GC_REGISTER_LONG_LINK(link, obj) \
GC_register_long_link(link, obj)
# define GC_REGISTER_DISPLACEMENT(n) GC_register_displacement(n)
#endif /* !GC_DEBUG */
/* The following are included because they are often convenient, and */
/* reduce the chance for a misspecified size argument. But calls may */
/* expand to something syntactically incorrect if t is a complicated */
/* type expression. Note that, unlike C++ new operator, these ones */
/* may return NULL (if out of memory). */
#define GC_NEW(t) ((t*)GC_MALLOC(sizeof(t)))
#define GC_NEW_ATOMIC(t) ((t*)GC_MALLOC_ATOMIC(sizeof(t)))
#define GC_NEW_UNCOLLECTABLE(t) ((t*)GC_MALLOC_UNCOLLECTABLE(sizeof(t)))
#ifdef GC_REQUIRE_WCSDUP
/* This might be unavailable on some targets (or not needed). */
/* wchar_t should be defined in stddef.h */
GC_API GC_ATTR_MALLOC wchar_t * GC_CALL
GC_wcsdup(const wchar_t *) GC_ATTR_NONNULL(1);
GC_API GC_ATTR_MALLOC wchar_t * GC_CALL
GC_debug_wcsdup(const wchar_t *, GC_EXTRA_PARAMS) GC_ATTR_NONNULL(1);
# ifdef GC_DEBUG
# define GC_WCSDUP(s) GC_debug_wcsdup(s, GC_EXTRAS)
# else
# define GC_WCSDUP(s) GC_wcsdup(s)
# endif
#endif /* GC_REQUIRE_WCSDUP */
/* Finalization. Some of these primitives are grossly unsafe. */
/* The idea is to make them both cheap, and sufficient to build */
/* a safer layer, closer to Modula-3, Java, or PCedar finalization. */
/* The interface represents my conclusions from a long discussion */
/* with Alan Demers, Dan Greene, Carl Hauser, Barry Hayes, */
/* Christian Jacobi, and Russ Atkinson. It's not perfect, and */
/* probably nobody else agrees with it. Hans-J. Boehm 3/13/92 */
typedef void (GC_CALLBACK * GC_finalization_proc)(void * /* obj */,
void * /* client_data */);
GC_API void GC_CALL GC_register_finalizer(void * /* obj */,
GC_finalization_proc /* fn */, void * /* cd */,
GC_finalization_proc * /* ofn */, void ** /* ocd */)
GC_ATTR_NONNULL(1);
GC_API void GC_CALL GC_debug_register_finalizer(void * /* obj */,
GC_finalization_proc /* fn */, void * /* cd */,
GC_finalization_proc * /* ofn */, void ** /* ocd */)
GC_ATTR_NONNULL(1);
/* When obj is no longer accessible, invoke */
/* (*fn)(obj, cd). If a and b are inaccessible, and */
/* a points to b (after disappearing links have been */
/* made to disappear), then only a will be */
/* finalized. (If this does not create any new */
/* pointers to b, then b will be finalized after the */
/* next collection.) Any finalizable object that */
/* is reachable from itself by following one or more */
/* pointers will not be finalized (or collected). */
/* Thus cycles involving finalizable objects should */
/* be avoided, or broken by disappearing links. */
/* All but the last finalizer registered for an object */
/* is ignored. */
/* No-op in the leak-finding mode. */
/* Finalization may be removed by passing 0 as fn. */
/* Finalizers are implicitly unregistered when they are */
/* enqueued for finalization (i.e. become ready to be */
/* finalized). */
/* The old finalizer and client data are stored in */
/* *ofn and *ocd. (ofn and/or ocd may be NULL. */
/* The allocator lock is held while *ofn and *ocd are */
/* updated. In case of error (no memory to register */
/* new finalizer), *ofn and *ocd remain unchanged.) */
/* Fn is never invoked on an accessible object, */
/* provided hidden pointers are converted to real */
/* pointers only if the allocator lock is held, at */
/* least in the reader mode, and such conversions are */
/* not performed by finalization routines. */
/* If GC_register_finalizer is aborted as a result of */
/* a signal, the object may be left with no */
/* finalization, even if neither the old nor new */
/* finalizer were NULL. */
/* Obj should be the starting address of an object */
/* allocated by GC_malloc or friends. Obj may also be */
/* NULL or point to something outside GC heap (in this */
/* case, fn is ignored, *ofn and *ocd are set to NULL). */
/* Note that any garbage collectible object referenced */
/* by cd will be considered accessible until the */
/* finalizer is invoked. */
/* Another versions of the above follow. It ignores */
/* self-cycles, i.e. pointers from a finalizable object to */
/* itself. There is a stylistic argument that this is wrong, */
/* but it's unavoidable for C++, since the compiler may */
/* silently introduce these. It's also benign in that specific */
/* case. And it helps if finalizable objects are split to */
/* avoid cycles. */
/* Note that cd will still be viewed as accessible, even if it */
/* refers to the object itself. */
GC_API void GC_CALL GC_register_finalizer_ignore_self(void * /* obj */,
GC_finalization_proc /* fn */, void * /* cd */,
GC_finalization_proc * /* ofn */, void ** /* ocd */)
GC_ATTR_NONNULL(1);
GC_API void GC_CALL GC_debug_register_finalizer_ignore_self(void * /* obj */,
GC_finalization_proc /* fn */, void * /* cd */,
GC_finalization_proc * /* ofn */, void ** /* ocd */)
GC_ATTR_NONNULL(1);
/* Another version of the above. It ignores all cycles. */
/* It should probably only be used by Java implementations. */
/* Note that cd will still be viewed as accessible, even if it */
/* refers to the object itself. */
GC_API void GC_CALL GC_register_finalizer_no_order(void * /* obj */,
GC_finalization_proc /* fn */, void * /* cd */,
GC_finalization_proc * /* ofn */, void ** /* ocd */)
GC_ATTR_NONNULL(1);
GC_API void GC_CALL GC_debug_register_finalizer_no_order(void * /* obj */,
GC_finalization_proc /* fn */, void * /* cd */,
GC_finalization_proc * /* ofn */, void ** /* ocd */)
GC_ATTR_NONNULL(1);
/* This is a special finalizer that is useful when an object's */
/* finalizer must be run when the object is known to be no */
/* longer reachable, not even from other finalizable objects. */
/* It behaves like "normal" finalization, except that the */
/* finalizer is not run while the object is reachable from */
/* other objects specifying unordered finalization. */
/* Effectively it allows an object referenced, possibly */
/* indirectly, from an unordered finalizable object to override */
/* the unordered finalization request. */
/* This can be used in combination with finalizer_no_order so */
/* as to release resources that must not be released while an */
/* object can still be brought back to life by other */
/* finalizers. */
/* Only works if GC_java_finalization is set. Probably only */
/* of interest when implementing a language that requires */
/* unordered finalization (e.g. Java, C#). */
GC_API void GC_CALL GC_register_finalizer_unreachable(void * /* obj */,
GC_finalization_proc /* fn */, void * /* cd */,
GC_finalization_proc * /* ofn */, void ** /* ocd */)
GC_ATTR_NONNULL(1);
GC_API void GC_CALL GC_debug_register_finalizer_unreachable(void * /* obj */,
GC_finalization_proc /* fn */, void * /* cd */,
GC_finalization_proc * /* ofn */, void ** /* ocd */)
GC_ATTR_NONNULL(1);
#define GC_NO_MEMORY 2 /* Failure due to lack of memory. */
/* The following routine may be used to break cycles between */
/* finalizable objects, thus causing cyclic finalizable */
/* objects to be finalized in the correct order. Standard */
/* use involves calling GC_register_disappearing_link(&p), */
/* where p is a pointer that is not followed by finalization */
/* code, and should not be considered in determining */
/* finalization order. */
GC_API int GC_CALL GC_register_disappearing_link(void ** /* link */)
GC_ATTR_NONNULL(1);
/* Link should point to a field of a heap allocated */
/* object obj. *link will be cleared when obj is */
/* found to be inaccessible. This happens BEFORE any */
/* finalization code is invoked, and BEFORE any */
/* decisions about finalization order are made. */
/* This is useful in telling the finalizer that */
/* some pointers are not essential for proper */
/* finalization. This may avoid finalization cycles. */
/* Note that obj may be resurrected by another */
/* finalizer, and thus the clearing of *link may */
/* be visible to non-finalization code. */
/* There's an argument that an arbitrary action should */
/* be allowed here, instead of just clearing a pointer. */
/* But this causes problems if that action alters, or */
/* examines connectivity. Returns GC_DUPLICATE if link */
/* was already registered, GC_SUCCESS if registration */
/* succeeded, GC_NO_MEMORY if it failed for lack of */
/* memory, and GC_oom_fn did not handle the problem. */
/* Only exists for backward compatibility. See below: */
GC_API int GC_CALL GC_general_register_disappearing_link(void ** /* link */,
const void * /* obj */)
GC_ATTR_NONNULL(1) GC_ATTR_NONNULL(2);
/* A slight generalization of the above. *link is */
/* cleared when obj first becomes inaccessible. This */
/* can be used to implement weak pointers easily and */
/* safely. Typically link will point to a location */
/* (in a GC-allocated object or not) holding */
/* a disguised pointer to obj. (A pointer inside */
/* an "atomic" object is effectively disguised.) */
/* In this way, weak pointers are broken before any */
/* object reachable from them gets finalized. */
/* Each link may be registered only with one obj value, */
/* i.e. all objects but the last one (link registered */
/* with) are ignored. This was added after a long */
/* email discussion with John Ellis. */
/* link must be non-NULL (and be properly aligned). */
/* obj must be a pointer to the beginning of an object */
/* allocated by GC_malloc or friends. A link */
/* disappears when it is unregistered manually, or when */
/* (*link) is cleared, or when the object containing */
/* this link is garbage collected. It is unsafe to */
/* explicitly deallocate the object containing link. */
/* Explicit deallocation of obj may or may not cause */
/* link to eventually be cleared. No-op in the */
/* leak-finding mode. This function can be used to */
/* implement certain types of weak pointers. Note, */
/* however, this generally requires that the allocator */
/* lock is held, at least in the reader mode (e.g. */
/* using GC_call_with_reader_lock), when the disguised */
/* pointer is accessed. Otherwise a strong pointer */
/* could be recreated between the time the collector */
/* decides to reclaim the object and the link is */
/* cleared. Returns GC_SUCCESS if registration */
/* succeeded (a new link is registered), GC_DUPLICATE */
/* if link was already registered (with some object), */
/* GC_NO_MEMORY if registration failed for lack of */
/* memory (and GC_oom_fn did not handle the problem), */
/* GC_UNIMPLEMENTED if GC_find_leak is true. */
GC_API int GC_CALL GC_move_disappearing_link(void ** /* link */,
void ** /* new_link */)
GC_ATTR_NONNULL(2);
/* Moves a link previously registered via */
/* GC_general_register_disappearing_link (or */
/* GC_register_disappearing_link). Does not change the */
/* target object of the weak reference. Does not */
/* change (*new_link) content. May be called with */
/* new_link equal to link (to check whether link has */
/* been registered). Returns GC_SUCCESS on success, */
/* GC_DUPLICATE if there is already another */
/* disappearing link at the new location (never */
/* returned if new_link is equal to link), GC_NOT_FOUND */
/* if no link is registered at the original location. */
GC_API int GC_CALL GC_unregister_disappearing_link(void ** /* link */);
/* Undoes a registration by either of the above two */
/* routines. Returns 0 if link was not actually */
/* registered (otherwise returns 1). */
GC_API int GC_CALL GC_register_long_link(void ** /* link */,
const void * /* obj */)
GC_ATTR_NONNULL(1) GC_ATTR_NONNULL(2);
/* Similar to GC_general_register_disappearing_link but */
/* *link only gets cleared when obj becomes truly */
/* inaccessible. An object becomes truly inaccessible */
/* when it can no longer be resurrected from its */
/* finalizer (e.g. by assigning itself to a pointer */
/* traceable from root). This can be used to implement */
/* long weak pointers easily and safely. */
GC_API int GC_CALL GC_move_long_link(void ** /* link */,
void ** /* new_link */)
GC_ATTR_NONNULL(2);
/* Similar to GC_move_disappearing_link but for a link */
/* previously registered via GC_register_long_link. */
GC_API int GC_CALL GC_unregister_long_link(void ** /* link */);
/* Similar to GC_unregister_disappearing_link but for a */
/* registration by either of the above two routines. */
/* Support of toggle-ref style of external memory management */
/* without hooking up to the host retain/release machinery. */
/* The idea of toggle-ref is that an external reference to */
/* an object is kept and it can be either a strong or weak */
/* reference; a weak reference is used when the external peer */
/* has no interest in the object, and a strong otherwise. */
typedef enum {
GC_TOGGLE_REF_DROP,
GC_TOGGLE_REF_STRONG,
GC_TOGGLE_REF_WEAK
} GC_ToggleRefStatus;
/* The callback is to decide (return) the new state of a given */
/* object. Invoked by the collector for all objects registered */
/* for toggle-ref processing. Invoked with the allocator lock */
/* held but the world is running. */
typedef GC_ToggleRefStatus (GC_CALLBACK * GC_toggleref_func)(void * /* obj */);
/* Set (register) a callback that decides the state of a given */
/* object (by, probably, inspecting its native state). */
/* The argument may be 0 (means no callback). Both the setter */
/* and the getter acquire the allocator lock (in the reader */
/* mode in case of the getter). */
GC_API void GC_CALL GC_set_toggleref_func(GC_toggleref_func);
GC_API GC_toggleref_func GC_CALL GC_get_toggleref_func(void);
/* Register a given object for toggle-ref processing. It will */
/* be stored internally and the toggle-ref callback will be */
/* invoked on the object until the callback returns */
/* GC_TOGGLE_REF_DROP or the object is collected. If is_strong */
/* is true, then the object is registered with a strong ref, */
/* a weak one otherwise. Obj should be the starting address */
/* of an object allocated by GC_malloc (GC_debug_malloc) or */
/* friends. Returns GC_SUCCESS if registration succeeded (or */
/* no callback is registered yet), GC_NO_MEMORY if it failed */
/* for a lack of memory reason. */
GC_API int GC_CALL GC_toggleref_add(void * /* obj */, int /* is_strong */)
GC_ATTR_NONNULL(1);
GC_API int GC_CALL GC_debug_toggleref_add(void * /* obj */,
int /* is_strong */) GC_ATTR_NONNULL(1);
/* Finalizer callback support. Invoked by the collector (with */
/* the allocator lock held) for each unreachable object */
/* enqueued for finalization. */
typedef void (GC_CALLBACK * GC_await_finalize_proc)(void * /* obj */);
GC_API void GC_CALL GC_set_await_finalize_proc(GC_await_finalize_proc);
GC_API GC_await_finalize_proc GC_CALL GC_get_await_finalize_proc(void);
/* Zero means no callback. The setter */
/* and the getter acquire the allocator */
/* lock too (in the reader mode in case */
/* of the getter). */
/* Returns !=0 if GC_invoke_finalizers has something to do. */
/* Does not use any synchronization. */
GC_API int GC_CALL GC_should_invoke_finalizers(void);
/* Set maximum amount of finalizers to run during a single */
/* invocation of GC_invoke_finalizers. Zero means no limit. */
/* Both the setter and the getter acquire the allocator lock */
/* (in the reader mode in case of the getter). Note that */
/* invocation of GC_finalize_all resets the maximum amount */
/* value. */
GC_API void GC_CALL GC_set_interrupt_finalizers(unsigned);
GC_API unsigned GC_CALL GC_get_interrupt_finalizers(void);
GC_API int GC_CALL GC_invoke_finalizers(void);
/* Run finalizers for all objects that are ready to */
/* be finalized. Return the number of finalizers */
/* that were run. Normally this is also called */
/* implicitly during some allocations. If */
/* GC_finalize_on_demand is nonzero, it must be called */
/* explicitly. */
/* Explicitly tell the collector that an object is reachable */
/* at a particular program point. This prevents the argument */
/* pointer from being optimized away, even it is otherwise no */
/* longer needed. It should have no visible effect in the */
/* absence of finalizers or disappearing links. But it may be */
/* needed to prevent finalizers from running while the */
/* associated external resource is still in use. */
/* The function is sometimes called keep_alive in other */
/* settings. */
#if defined(__GNUC__) && !defined(__INTEL_COMPILER) \
&& !(defined(__APPLE__) && defined(__arm__) && defined(__TINYC__))
/* TCC (as of v0.9.28rc) does not support asm on macOS/arm. */
# if defined(__e2k__)
# define GC_reachable_here(ptr) \
__asm__ __volatile__ (" " : : "r"(ptr) : "memory")
# elif defined(__TINYC__)
# define GC_reachable_here(ptr) \
__asm__ __volatile__ (" " : : "g"(ptr) : "memory")
# else
# define GC_reachable_here(ptr) \
__asm__ __volatile__ (" " : : "X"(ptr) : "memory")
# endif
#elif defined(LINT2)
# define GC_reachable_here(ptr) GC_noop1(~(GC_word)(ptr)^(~(GC_word)0))
/* The expression is similar to that of COVERT_DATAFLOW(). */
#else
# define GC_reachable_here(ptr) GC_noop1_ptr(GC_CAST_AWAY_CONST_PVOID(ptr))
#endif
/* Make the argument of word type appear live to compiler. This could */
/* be used to prevent certain compiler false positive (FP) warnings and */
/* misoptimizations. Should be robust against the whole program */
/* analysis. */
GC_API void GC_CALL GC_noop1(GC_word);
/* Same as GC_noop1() but for a pointer. */
GC_API void GC_CALL GC_noop1_ptr(volatile void *);
/* GC_set_warn_proc can be used to redirect or filter warning messages. */
/* p may not be a NULL pointer. msg is printf format string (arg must */
/* match the format). Both the setter and the getter acquire the */
/* allocator lock (in the reader mode in case of the getter) to avoid */
/* data race. In GC v7.1 and before: the setter returned the value of */
/* old warn_proc. In GC v8.2.x and before: msg pointer type had no */
/* const qualifier. */
typedef void (GC_CALLBACK * GC_warn_proc)(const char * /* msg */,
GC_uintptr_t /* arg */);
GC_API void GC_CALL GC_set_warn_proc(GC_warn_proc /* p */) GC_ATTR_NONNULL(1);
GC_API GC_warn_proc GC_CALL GC_get_warn_proc(void);
/* GC_ignore_warn_proc may be used as an argument for GC_set_warn_proc */
/* to suppress all warnings (unless statistics printing is turned on). */
GC_API void GC_CALLBACK GC_ignore_warn_proc(const char *, GC_uintptr_t);
/* Change file descriptor of GC log. Unavailable on some targets. */
GC_API void GC_CALL GC_set_log_fd(int);
/* abort_func is invoked on GC fatal aborts (just before OS-dependent */
/* abort or exit(1) is called). Must be non-NULL. The default one */
/* outputs msg to stderr provided msg is non-NULL. msg is NULL if */
/* invoked before exit(1) otherwise msg is non-NULL (i.e., if invoked */
/* before abort). Both the setter and the getter acquire the allocator */
/* lock (in the reader mode in case of the getter). The setter does */
/* not change abort_func if the library has been compiled with */
/* SMALL_CONFIG defined. */
typedef void (GC_CALLBACK * GC_abort_func)(const char * /* msg */);
GC_API void GC_CALL GC_set_abort_func(GC_abort_func) GC_ATTR_NONNULL(1);
GC_API GC_abort_func GC_CALL GC_get_abort_func(void);
/* A portable way to abort the application because of not enough */
/* memory. */
GC_API void GC_CALL GC_abort_on_oom(void);
/* The following is intended to be used by a higher level (e.g. */
/* Java-like) finalization facility. It is expected that finalization */
/* code will arrange for hidden pointers to disappear. Otherwise, */
/* objects can be accessed after they have been collected. Should not */
/* be used in the leak-finding mode. */
/* Note that putting pointers in atomic objects or in non-pointer slots */
/* of "typed" objects is equivalent to disguising them in this way, and */
/* may have other advantages. Note also that some code relies on that */
/* the least significant bit of the argument (including for NULL) is */
/* inverted by these primitives. */
/* Important: converting a hidden pointer to a real pointer requires */
/* verifying that the object still exists; this should involve */
/* acquiring the allocator lock, at least in the reader mode, to avoid */
/* a race with the collector (e.g., one thread might fetch hidden link */
/* value, while another thread might collect the relevant object and */
/* reuse the free space for another object). */
typedef GC_uintptr_t GC_hidden_pointer;
#define GC_HIDE_POINTER(p) (~(GC_hidden_pointer)(p))
#define GC_REVEAL_POINTER(p) ((void *)GC_HIDE_POINTER(p))
#if defined(I_HIDE_POINTERS) || defined(GC_I_HIDE_POINTERS)
/* This exists only for compatibility (the GC-prefixed symbols are */
/* preferred for new code). */
# define HIDE_POINTER(p) GC_HIDE_POINTER(p)
# define REVEAL_POINTER(p) GC_REVEAL_POINTER(p)
#endif
/* A slightly modified version of GC_HIDE_POINTER which guarantees not */
/* to "hide" NULL (i.e. passing zero argument gives zero result). This */
/* might be useful in conjunction with GC_register_disappearing_link. */
/* Note that unlike GC_HIDE_POINTER, inversion of the least significant */
/* bit of the argument is not guaranteed. */
#define GC_HIDE_NZ_POINTER(p) ((GC_hidden_pointer)(-(GC_signed_word)(p)))
#define GC_REVEAL_NZ_POINTER(p) ((void *)GC_HIDE_NZ_POINTER(p))
/* The routines to acquire/release the GC (allocator) lock. */
/* The lock is not reentrant. GC_alloc_unlock() should not be called */
/* unless the allocator lock is acquired by the current thread. */
#ifdef GC_THREADS
GC_API void GC_CALL GC_alloc_lock(void);
GC_API void GC_CALL GC_alloc_unlock(void);
#else
/* No need for real locking if the client is single-threaded. */
# define GC_alloc_lock() (void)0
# define GC_alloc_unlock() (void)0
#endif /* !GC_THREADS */
typedef void * (GC_CALLBACK * GC_fn_type)(void * /* client_data */);
/* Execute given function with the allocator lock held (in the */
/* exclusive mode). */
GC_API void * GC_CALL GC_call_with_alloc_lock(GC_fn_type /* fn */,
void * /* client_data */) GC_ATTR_NONNULL(1);
/* Execute given function with the allocator lock held in the reader */
/* (shared) mode. The 3rd argument (release), if non-zero, indicates */
/* that fn wrote some data that should be made visible to the thread */
/* which acquires the allocator lock in the exclusive mode later. */
#ifdef GC_THREADS
GC_API void * GC_CALL GC_call_with_reader_lock(GC_fn_type /* fn */,
void * /* client_data */,
int /* release */) GC_ATTR_NONNULL(1);
#else
# define GC_call_with_reader_lock(fn, cd, r) ((void)(r), (fn)(cd))
#endif
/* These routines are intended to explicitly notify the collector */
/* of new threads. Often this is unnecessary because thread creation */
/* is implicitly intercepted by the collector, using header-file */
/* defines, or linker-based interception. In the long run the intent */
/* is to always make redundant registration safe. In the short run, */
/* this is being implemented a platform at a time. */
/* The interface is complicated by the fact that we probably will not */
/* ever be able to automatically determine the stack bottom for thread */
/* stacks on all platforms. */
/* Structure representing the bottom (cold end) of a thread stack. */
/* On most platforms this contains just a single address. */
struct GC_stack_base {
void * mem_base; /* the bottom of the general-purpose stack */
# if defined(__e2k__) \
|| defined(__ia64) || defined(__ia64__) || defined(_M_IA64)
void * reg_base; /* the bottom of the register stack */
# endif
};
typedef void * (GC_CALLBACK * GC_stack_base_func)(
struct GC_stack_base * /* sb */, void * /* arg */);
/* Call a function with a stack base structure corresponding to */
/* somewhere in the GC_call_with_stack_base frame. This often can */
/* be used to provide a sufficiently accurate stack bottom. And we */
/* implement it everywhere. */
GC_API void * GC_CALL GC_call_with_stack_base(GC_stack_base_func /* fn */,
void * /* arg */) GC_ATTR_NONNULL(1);
#define GC_SUCCESS 0
#define GC_DUPLICATE 1 /* Was already registered. */
#define GC_NO_THREADS 2 /* No thread support in GC. */
/* GC_NO_THREADS is not returned by any GC function anymore. */
#define GC_UNIMPLEMENTED 3 /* Not yet implemented on this platform. */
#define GC_NOT_FOUND 4 /* Requested link not found (returned */
/* by GC_move_disappearing_link). */
/* Start the parallel marker threads, if available. Useful, e.g., */
/* after POSIX fork in a child process (provided not followed by exec) */
/* or in single-threaded clients (provided it is OK for the client to */
/* perform marking in parallel). Acquires the allocator lock to avoid */
/* a race. */
GC_API void GC_CALL GC_start_mark_threads(void);
#if defined(GC_DARWIN_THREADS) || defined(GC_WIN32_THREADS)
/* Use implicit thread registration and processing (via Win32 DllMain */
/* or Darwin task_threads). Deprecated. Must be called before */
/* GC_INIT() and other GC routines. Should be avoided if */
/* GC_pthread_create, GC_beginthreadex (or GC_CreateThread), or */
/* GC_register_my_thread could be called instead. */
/* Includes a GC_init() call. Disables parallelized GC on Win32. */
GC_API void GC_CALL GC_use_threads_discovery(void);
#endif
#ifdef GC_THREADS
/* Suggest the GC to use the specific signal to suspend threads. */
/* Has no effect after GC_init and on non-POSIX systems. */
GC_API void GC_CALL GC_set_suspend_signal(int);
/* Suggest the GC to use the specific signal to resume threads. */
/* Has no effect after GC_init and on non-POSIX systems. */
/* The same signal might be used for threads suspension and restart. */
GC_API void GC_CALL GC_set_thr_restart_signal(int);
/* Return the signal number (constant after initialization) used by */
/* the GC to suspend threads on POSIX systems. Return -1 otherwise. */
GC_API int GC_CALL GC_get_suspend_signal(void);
/* Return the signal number (constant after initialization) used by */
/* the garbage collector to restart (resume) threads on POSIX */
/* systems. Return -1 otherwise. */
GC_API int GC_CALL GC_get_thr_restart_signal(void);
/* Explicitly enable GC_register_my_thread() invocation. */
/* Done implicitly if a GC thread-creation function is called (or */
/* implicit thread registration is activated, or the collector is */
/* compiled with GC_ALWAYS_MULTITHREADED defined). Otherwise, it */
/* must be called from the main (or any previously registered) thread */
/* between the collector initialization and the first explicit */
/* registering of a thread (it should be called as late as possible). */
/* Includes a GC_start_mark_threads() call. */
GC_API void GC_CALL GC_allow_register_threads(void);
/* Register the current thread, with the indicated stack bottom, as */
/* a new thread whose stack(s) should be traced by the GC. If it */
/* is not implicitly called by the GC, this must be called before a */
/* thread can allocate garbage collected memory, or assign pointers */
/* to the garbage collected heap. Once registered, a thread will be */
/* stopped during garbage collections. */
/* This call must be previously enabled (see above). */
/* This should never be called from the main thread, where it is */
/* always done implicitly. This is normally done implicitly if GC_ */
/* functions are called to create the thread, e.g. by including gc.h */
/* (which redefines some system functions) before calling the system */
/* thread creation function. Nonetheless, thread cleanup routines */
/* (e.g., pthread key destructor) typically require manual thread */
/* registering (and unregistering) if pointers to GC-allocated */
/* objects are manipulated inside. */
/* It is also always done implicitly on some platforms if */
/* GC_use_threads_discovery() is called at start-up. Except for the */
/* latter case, the explicit call is normally required for threads */
/* created by third-party libraries. */
/* A manually registered thread requires manual unregistering. */
/* Returns GC_SUCCESS on success, GC_DUPLICATE if already registered. */
GC_API int GC_CALL GC_register_my_thread(const struct GC_stack_base *)
GC_ATTR_NONNULL(1);
/* Return 1 (true) if the calling (current) thread is registered with */
/* the garbage collector, 0 otherwise. Acquires the allocator lock */
/* in the reader mode. If the thread is finished (e.g. running in */
/* a destructor and not registered manually again), it is considered */
/* as not registered. */
GC_API int GC_CALL GC_thread_is_registered(void);
/* Notify the collector about the stack and the alt-stack of the */
/* current thread. normstack and normstack_size are used to */
/* determine the "normal" stack boundaries when a thread is suspended */
/* while it is on an alt-stack. Acquires the allocator lock in the */
/* reader mode. */
GC_API void GC_CALL GC_register_altstack(void * /* normstack */,
size_t /* normstack_size */,
void * /* altstack */,
size_t /* altstack_size */);
/* Unregister the current thread. Only an explicitly registered */
/* thread (i.e. for which GC_register_my_thread() returns GC_SUCCESS) */
/* is allowed (and required) to call this function. (As a special */
/* exception, it is also allowed to once unregister the main thread.) */
/* The thread may no longer allocate garbage collected memory or */
/* manipulate pointers to the garbage collected heap after making */
/* this call. Specifically, if it wants to return or otherwise */
/* communicate a pointer to the garbage-collected heap to another */
/* thread, it must do this before calling GC_unregister_my_thread, */
/* most probably by saving it in a global data structure. Must not */
/* be called inside a GC callback function (except for */
/* GC_call_with_stack_base() one). Always returns GC_SUCCESS. */
GC_API int GC_CALL GC_unregister_my_thread(void);
/* Stop/start the world explicitly. Not recommended for general use. */
GC_API void GC_CALL GC_stop_world_external(void);
GC_API void GC_CALL GC_start_world_external(void);
/* Provide a verifier/modifier of the stack pointer when pushing the */
/* thread stacks. This might be useful for a crude integration */
/* with certain coroutine implementations. (*sp_ptr) is the captured */
/* stack pointer of the suspended thread with pthread_id (the latter */
/* is actually of pthread_t type). The functionality is unsupported */
/* on some targets (the getter always returns 0 in such a case). */
/* Both the setter and the getter acquire the allocator lock (in the */
/* reader mode in case of the getter). The client function (if */
/* provided) is called with the allocator lock held and, might be, */
/* with the world stopped. */
typedef void (GC_CALLBACK * GC_sp_corrector_proc)(void ** /* sp_ptr */,
void * /* pthread_id */);
GC_API void GC_CALL GC_set_sp_corrector(GC_sp_corrector_proc);
GC_API GC_sp_corrector_proc GC_CALL GC_get_sp_corrector(void);
#endif /* GC_THREADS */
/* Wrapper for functions that are likely to block (or, at least, do not */
/* allocate garbage collected memory and/or manipulate pointers to the */
/* garbage collected heap) for an appreciable length of time. While fn */
/* is running, the collector is said to be in the "inactive" state for */
/* the current thread (this means that the thread is not suspended and */
/* the thread's stack frames "belonging" to the functions in the */
/* "inactive" state are not scanned during garbage collections). It is */
/* assumed that the collector is already initialized and the current */
/* thread is registered. It is allowed for fn to call */
/* GC_call_with_gc_active() (even recursively), thus temporarily */
/* toggling the collector's state back to "active". The latter */
/* technique might be used to make stack scanning more precise (i.e. */
/* scan only stack frames of functions that allocate garbage collected */
/* memory and/or manipulate pointers to the garbage collected heap). */
/* Acquires the allocator lock in the reader mode (but fn is called */
/* not holding it). */
GC_API void * GC_CALL GC_do_blocking(GC_fn_type /* fn */,
void * /* client_data */) GC_ATTR_NONNULL(1);
/* Call a function switching to the "active" state of the collector for */
/* the current thread (i.e. the user function is allowed to call any */
/* GC function and/or manipulate pointers to the garbage collected */
/* heap). GC_call_with_gc_active() has the functionality opposite to */
/* GC_do_blocking() one. It is assumed that the collector is already */
/* initialized and the current thread is registered. fn may toggle */
/* the collector thread's state temporarily to "inactive" one by using */
/* GC_do_blocking. GC_call_with_gc_active() often can be used to */
/* provide a sufficiently accurate stack bottom. Acquires the */
/* allocator lock in the reader mode (but fn is called not holding it). */
GC_API void * GC_CALL GC_call_with_gc_active(GC_fn_type /* fn */,
void * /* client_data */) GC_ATTR_NONNULL(1);
/* Attempt to fill in the GC_stack_base structure with the stack bottom */
/* for this thread. This appears to be required to implement anything */
/* like the JNI AttachCurrentThread in an environment in which new */
/* threads are not automatically registered with the collector. */
/* It is also unfortunately hard to implement well on many platforms. */
/* Returns GC_SUCCESS or GC_UNIMPLEMENTED. Acquires the allocator lock */
/* on some platforms. */
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *)
GC_ATTR_NONNULL(1);
/* Fill in the GC_stack_base structure with the cold end (bottom) of */
/* the stack of the current thread (or coroutine). */
/* Unlike GC_get_stack_base, it retrieves the value stored in the */
/* collector (which is initially set by the collector upon the thread */
/* is started or registered manually but it could be later updated by */
/* client using GC_set_stackbottom). Returns the GC-internal non-NULL */
/* handle of the thread which could be passed to GC_set_stackbottom */
/* later. It is assumed that the collector is already initialized and */
/* the thread is registered. Acquires the allocator lock in the reader */
/* mode. */
GC_API void * GC_CALL GC_get_my_stackbottom(struct GC_stack_base *)
GC_ATTR_NONNULL(1);
/* Set the cool end of the user (coroutine) stack of the specified */
/* thread. The GC thread handle is either the one returned by */
/* GC_get_my_stackbottom or NULL (the latter designates the current */
/* thread). The caller should hold the allocator lock (e.g. using */
/* GC_call_with_reader_lock with release argument set to 1), the reader */
/* mode should be enough typically, at least for the collector itself */
/* (the client is responsible to avoid data race between this and */
/* GC_get_my_stackbottom functions if the client acquires the allocator */
/* lock in the reader mode). Also, the function could be used for */
/* setting GC_stackbottom value (the bottom of the primordial thread) */
/* before the collector is initialized (the allocator lock is not */
/* needed to be acquired at all in this case). */
GC_API void GC_CALL GC_set_stackbottom(void * /* gc_thread_handle */,
const struct GC_stack_base *)
GC_ATTR_NONNULL(2);
/* The following routines are primarily intended for use with a */
/* preprocessor which inserts calls to check C pointer arithmetic. */
/* They indicate failure by invoking the corresponding _print_proc. */
/* Checked pointer pre- and post- increment operations. Note that */
/* the second argument is in units of bytes, not multiples of the */
/* object size. This should either be invoked from a macro, or the */
/* call should be automatically generated. */
GC_API void * GC_CALL GC_pre_incr(void **, ptrdiff_t /* how_much */)
GC_ATTR_NONNULL(1);
GC_API void * GC_CALL GC_post_incr(void **, ptrdiff_t /* how_much */)
GC_ATTR_NONNULL(1);
/* Check that p and q point to the same object. GC_same_obj_print_proc */
/* is called (fail by default) if they do not. Succeeds, as well, if */
/* neither p nor q points to the heap. (May succeed also if both p and */
/* q point to between heap objects.) Returns the first argument. */
/* (The returned value may be hard to use due to typing issues. But if */
/* we had a suitable preprocessor...) We assume this is somewhat */
/* performance critical (it should not be called by production code, */
/* of course, but it can easily make even debugging intolerably slow). */
GC_API void * GC_CALL GC_same_obj(void * /* p */, void * /* q */);
/* Check that p is visible to the collector as a possibly pointer */
/* containing location. If it is not, invoke GC_is_visible_print_proc */
/* (fail by default). Always returns the argument. May erroneously */
/* succeed in hard cases. The function is intended for debugging use */
/* with untyped allocations. (The idea is that it should be possible, */
/* though slow, to add such a call to all indirect pointer stores.) */
/* Currently useless for the multi-threaded worlds. */
GC_API void * GC_CALL GC_is_visible(void * /* p */);
/* Check that if p is a pointer to a heap page, then it points to */
/* a valid displacement within a heap object. If it is not, invoke */
/* GC_is_valid_displacement_print_proc (fail by default). Always */
/* returns the argument. Uninteresting with all-interior-pointers on. */
/* Note that we do not acquire the allocator lock, since nothing */
/* relevant about the header should change while we have a valid object */
/* pointer to the block. */
GC_API void * GC_CALL GC_is_valid_displacement(void * /* p */);
/* Explicitly dump the GC state. This is most often called from the */
/* debugger, or by setting the GC_DUMP_REGULARLY environment variable, */
/* but it may be useful to call it from client code during debugging. */
/* The current collection number is printed in the header of the dump. */
/* Acquires the allocator lock in the reader mode to avoid data race. */
/* Defined only if the library has been compiled without NO_DEBUGGING. */
GC_API void GC_CALL GC_dump(void);
/* The same as GC_dump but allows to specify the name of dump and does */
/* not acquire the allocator lock. If name is non-NULL, it is printed */
/* to help identifying individual dumps. Otherwise the current */
/* collection number is used as the name. */
/* Defined only if the library has been compiled without NO_DEBUGGING. */
GC_API void GC_CALL GC_dump_named(const char * /* name */);
/* Dump information about each block of every GC memory section. */
/* Defined only if the library has been compiled without NO_DEBUGGING. */
GC_API void GC_CALL GC_dump_regions(void);
/* Dump information about every registered disappearing link and */
/* finalizable object. */
/* Defined only if the library has been compiled without NO_DEBUGGING. */
GC_API void GC_CALL GC_dump_finalization(void);
/* Safer, but slow, pointer addition. Probably useful mainly with */
/* a preprocessor. Useful only for heap pointers. */
/* Only the macros without trailing digits are meant to be used */
/* by clients. These are designed to model the available C pointer */
/* arithmetic expressions. */
/* Even then, these are probably more useful as */
/* documentation than as part of the API. */
/* Note that GC_PTR_ADD evaluates the first argument more than once. */
#if defined(GC_DEBUG) && (defined(__GNUC__) || defined(__clang__))
# define GC_PTR_ADD3(x, n, type_of_result) \
((type_of_result)GC_same_obj((x) + (n), (x)))
# define GC_PRE_INCR3(x, n, type_of_result) \
((type_of_result)GC_pre_incr((void **)&(x), (n) * sizeof(*(x))))
# define GC_POST_INCR3(x, n, type_of_result) \
((type_of_result)GC_post_incr((void **)&(x), (n) * sizeof(*(x))))
# define GC_PTR_ADD(x, n) GC_PTR_ADD3(x, n, __typeof__(x))
# define GC_PRE_INCR(x, n) GC_PRE_INCR3(x, n, __typeof__(x))
# define GC_POST_INCR(x) GC_POST_INCR3(x, 1, __typeof__(x))
# define GC_POST_DECR(x) GC_POST_INCR3(x, -1, __typeof__(x))
#else /* !GC_DEBUG || !__GNUC__ */
/* We can't do this right without typeof, which ANSI decided was not */
/* sufficiently useful. Without it we resort to the non-debug version. */
/* TODO: This should eventually support C++0x decltype. */
# define GC_PTR_ADD(x, n) ((x) + (n))
# define GC_PRE_INCR(x, n) ((x) += (n))
# define GC_POST_INCR(x) ((x)++)
# define GC_POST_DECR(x) ((x)--)
#endif /* !GC_DEBUG || !__GNUC__ */
/* Safer assignment of a pointer to a non-stack location. */
#ifdef GC_DEBUG
# define GC_PTR_STORE(p, q) \
(*(void **)GC_is_visible((void *)(p)) = \
GC_is_valid_displacement((void *)(q)))
#else
# define GC_PTR_STORE(p, q) (*(void **)(p) = (void *)(q))
#endif
/* GC_PTR_STORE_AND_DIRTY(p,q) is equivalent to GC_PTR_STORE(p,q) */
/* followed by GC_END_STUBBORN_CHANGE(p) and GC_reachable_here(q) */
/* (assuming p and q do not have side effects). */
GC_API void GC_CALL GC_ptr_store_and_dirty(void * /* p */,
const void * /* q */);
GC_API void GC_CALL GC_debug_ptr_store_and_dirty(void * /* p */,
const void * /* q */);
#ifdef GC_PTHREADS
/* For pthread support, we generally need to intercept a number of */
/* thread library calls. We do that here by macro defining them. */
# ifdef __cplusplus
} /* extern "C" */
# endif
# include "gc_pthread_redirects.h"
# ifdef __cplusplus
extern "C" {
# endif
#endif
/* This returns a list of objects with the link pointer located at the */
/* beginning of each object. The use of such list can greatly reduce */
/* lock contention problems, since the allocator lock can be acquired */
/* and released many fewer times. Note that there is no "atomic" */
/* version of this function, as otherwise the links would not be seen */
/* by the collector. If the argument is zero, then it is treated as 1. */
GC_API GC_ATTR_MALLOC void * GC_CALL GC_malloc_many(size_t /* lb */);
#define GC_NEXT(p) (*(void * *)(p)) /* Retrieve the next element */
/* in the returned list. */
/* A filter function to control the scanning of dynamic libraries. */
/* If implemented, called by GC before registering a dynamic library */
/* (discovered by GC) section as a static data root (called only as */
/* a last reason not to register). The filename of the library, the */
/* address and the length of the memory region (section) are passed. */
/* This routine should return nonzero if that region should be scanned. */
/* Always called with the allocator lock held. Depending on the */
/* platform, might be called with the "world" stopped. */
typedef int (GC_CALLBACK * GC_has_static_roots_func)(
const char * /* dlpi_name */,
void * /* section_start */,
size_t /* section_size */);
/* Register a new callback (a user-supplied filter) to control the */
/* scanning of dynamic libraries. Replaces any previously registered */
/* callback. May be 0 (means no filtering). May be unused on some */
/* platforms (if the filtering is unimplemented or inappropriate). */
GC_API void GC_CALL GC_register_has_static_roots_callback(
GC_has_static_roots_func);
#if !defined(CPPCHECK) && !defined(GC_WINDOWS_H_INCLUDED) && defined(WINAPI)
/* windows.h is included before gc.h */
# define GC_WINDOWS_H_INCLUDED
#endif
#if defined(GC_WIN32_THREADS) \
&& (!defined(GC_PTHREADS) || defined(GC_BUILD) \
|| defined(GC_WINDOWS_H_INCLUDED))
/* Note: for Cygwin and pthreads-win32, this is skipped */
/* unless windows.h is included before gc.h. */
# if (!defined(GC_NO_THREAD_DECLS) || defined(GC_BUILD)) \
&& !defined(GC_DONT_INCL_WINDOWS_H)
# ifdef __cplusplus
} /* Including windows.h in an extern "C" context no longer works. */
# endif
# if !defined(_WIN32_WCE) && !defined(__CEGCC__)
# include <process.h> /* For _beginthreadex, _endthreadex */
# endif
# if defined(GC_BUILD) || !defined(GC_DONT_INCLUDE_WINDOWS_H)
# include <windows.h>
# define GC_WINDOWS_H_INCLUDED
# endif
# ifdef __cplusplus
extern "C" {
# endif
# ifdef GC_UNDERSCORE_STDCALL
/* Explicitly prefix exported/imported WINAPI (__stdcall) symbols */
/* with '_' (underscore). Might be useful if MinGW/x86 is used. */
# define GC_CreateThread _GC_CreateThread
# define GC_ExitThread _GC_ExitThread
# endif
# ifndef DECLSPEC_NORETURN
/* Typically defined in winnt.h. */
# ifdef GC_WINDOWS_H_INCLUDED
# define DECLSPEC_NORETURN /* empty */
# else
# define DECLSPEC_NORETURN __declspec(noreturn)
# endif
# endif
# ifdef _WIN64
# define GC_WIN32_SIZE_T GC_uintptr_t
# elif defined(GC_WINDOWS_H_INCLUDED)
# define GC_WIN32_SIZE_T DWORD
# else
# define GC_WIN32_SIZE_T unsigned long
# endif
# ifdef GC_INSIDE_DLL
/* Export GC DllMain to be invoked from client DllMain. */
# ifdef GC_UNDERSCORE_STDCALL
# define GC_DllMain _GC_DllMain
# endif
# ifdef GC_WINDOWS_H_INCLUDED
GC_API BOOL WINAPI GC_DllMain(HINSTANCE /* inst */,
ULONG /* reason */,
LPVOID /* reserved */);
# else
GC_API int __stdcall GC_DllMain(void *, unsigned long, void *);
# endif
# endif /* GC_INSIDE_DLL */
/* All threads must be created using GC_CreateThread or */
/* GC_beginthreadex, or must explicitly call GC_register_my_thread */
/* (and call GC_unregister_my_thread before thread termination), so */
/* that they will be recorded in the thread table. For backward */
/* compatibility, it is possible to build the GC with GC_DLL */
/* defined, and to call GC_use_threads_discovery. This implicitly */
/* registers all created threads, but appears to be less robust. */
/* Currently the collector expects all threads to fall through and */
/* terminate normally, or call GC_endthreadex() or GC_ExitThread, */
/* so that the thread is properly unregistered. */
# ifdef GC_WINDOWS_H_INCLUDED
GC_API HANDLE WINAPI GC_CreateThread(
LPSECURITY_ATTRIBUTES /* lpThreadAttributes */,
GC_WIN32_SIZE_T /* dwStackSize */,
LPTHREAD_START_ROUTINE /* lpStartAddress */,
LPVOID /* lpParameter */, DWORD /* dwCreationFlags */,
LPDWORD /* lpThreadId */);
GC_API DECLSPEC_NORETURN void WINAPI GC_ExitThread(
DWORD /* dwExitCode */);
# else
struct _SECURITY_ATTRIBUTES;
GC_API void *__stdcall GC_CreateThread(struct _SECURITY_ATTRIBUTES *,
GC_WIN32_SIZE_T,
unsigned long (__stdcall *)(void *),
void *, unsigned long, unsigned long *);
GC_API DECLSPEC_NORETURN void __stdcall GC_ExitThread(unsigned long);
# endif
# if !defined(_WIN32_WCE) && !defined(__CEGCC__)
GC_API GC_uintptr_t GC_CALL GC_beginthreadex(
void * /* security */, unsigned /* stack_size */,
unsigned (__stdcall *)(void *),
void * /* arglist */, unsigned /* initflag */,
unsigned * /* thrdaddr */);
/* Note: _endthreadex() is not currently marked as no-return in */
/* VC++ and MinGW headers, so we don't mark it neither. */
GC_API void GC_CALL GC_endthreadex(unsigned /* retval */);
# endif /* !_WIN32_WCE */
# endif /* !GC_NO_THREAD_DECLS */
# ifdef GC_WINMAIN_REDIRECT
/* The collector provides the real WinMain(), which starts a new */
/* thread to call GC_WinMain() after initializing the GC. */
# define WinMain GC_WinMain
# endif
/* For compatibility only. */
# define GC_use_DllMain GC_use_threads_discovery
# ifndef GC_NO_THREAD_REDIRECTS
# define CreateThread GC_CreateThread
# define ExitThread GC_ExitThread
# undef _beginthreadex
# define _beginthreadex GC_beginthreadex
# undef _endthreadex
# define _endthreadex GC_endthreadex
/* #define _beginthread { > "Please use _beginthreadex instead of _beginthread" < } */
# endif /* !GC_NO_THREAD_REDIRECTS */
#endif /* GC_WIN32_THREADS */
/* The setter and the getter for switching "unmap as much as possible" */
/* mode on(1) and off(0). Has no effect unless unmapping is turned on. */
/* Has no effect on implicitly-initiated garbage collections. Initial */
/* value is controlled by GC_FORCE_UNMAP_ON_GCOLLECT. The setter and */
/* the getter are unsynchronized. */
GC_API void GC_CALL GC_set_force_unmap_on_gcollect(int);
GC_API int GC_CALL GC_get_force_unmap_on_gcollect(void);
/* Fully portable code should call GC_INIT() from the main program */
/* before making any other GC_ calls. On most platforms this is a */
/* no-op and the collector self-initializes. But a number of */
/* platforms make that too hard. */
/* A GC_INIT call is required if the collector is built with */
/* THREAD_LOCAL_ALLOC defined and the initial allocation call is not */
/* to GC_malloc() or GC_malloc_atomic(). */
#if defined(__CYGWIN32__) || defined(__CYGWIN__)
/* Similarly gnu-win32 DLLs need explicit initialization from the */
/* main program, as does AIX. */
# ifdef __x86_64__
/* Cygwin/x64 does not add leading underscore to symbols anymore. */
extern int __data_start__[], __data_end__[];
extern int __bss_start__[], __bss_end__[];
# define GC_DATASTART (GC_ADDR_LT((char *)__data_start__, \
(char *)__bss_start__) \
? (void *)__data_start__ : (void *)__bss_start__)
# define GC_DATAEND (GC_ADDR_LT((char *)__bss_end__, (char *)__data_end__) \
? (void *)__data_end__ : (void *)__bss_end__)
# else
extern int _data_start__[], _data_end__[], _bss_start__[], _bss_end__[];
# define GC_DATASTART (GC_ADDR_LT((char *)_data_start__, \
(char *)_bss_start__) \
? (void *)_data_start__ : (void *)_bss_start__)
# define GC_DATAEND (GC_ADDR_LT((char *)_bss_end__, (char *)_data_end__) \
? (void *)_data_end__ : (void *)_bss_end__)
# endif /* !__x86_64__ */
# define GC_INIT_CONF_ROOTS GC_add_roots(GC_DATASTART, GC_DATAEND); \
GC_gcollect() /* For blacklisting. */
/* Required at least if GC is in a DLL. And doesn't hurt. */
#elif defined(_AIX)
extern int _data[], _end[];
# define GC_DATASTART ((void *)_data)
# define GC_DATAEND ((void *)_end)
# define GC_INIT_CONF_ROOTS GC_add_roots(GC_DATASTART, GC_DATAEND)
#elif (defined(HOST_ANDROID) || defined(__ANDROID__)) \
&& defined(IGNORE_DYNAMIC_LOADING)
/* This is ugly but seems the only way to register data roots of the */
/* client shared library if the GC dynamic loading support is off. */
# pragma weak __dso_handle
extern int __dso_handle[];
GC_API void * GC_CALL GC_find_limit(void * /* start */, int /* up */);
# define GC_INIT_CONF_ROOTS (void)(__dso_handle != 0 \
? (GC_add_roots(__dso_handle, \
GC_find_limit(__dso_handle, \
1 /*up*/)), 0) : 0)
#else
# define GC_INIT_CONF_ROOTS /* empty */
#endif
#ifdef GC_DONT_EXPAND
/* Set GC_dont_expand to true at start-up. */
# define GC_INIT_CONF_DONT_EXPAND GC_set_dont_expand(1)
#else
# define GC_INIT_CONF_DONT_EXPAND /* empty */
#endif
#ifdef GC_FORCE_UNMAP_ON_GCOLLECT
/* Turn on "unmap as much as possible on explicit GC" mode at start-up */
# define GC_INIT_CONF_FORCE_UNMAP_ON_GCOLLECT \
GC_set_force_unmap_on_gcollect(1)
#else
# define GC_INIT_CONF_FORCE_UNMAP_ON_GCOLLECT /* empty */
#endif
#ifdef GC_DONT_GC
/* This is for debugging only (useful if environment variables are */
/* unsupported); cannot call GC_disable as goes before GC_init. */
# define GC_INIT_CONF_MAX_RETRIES (void)(GC_dont_gc = 1)
#elif defined(GC_MAX_RETRIES) && !defined(CPPCHECK)
/* Set GC_max_retries to the desired value at start-up */
# define GC_INIT_CONF_MAX_RETRIES GC_set_max_retries(GC_MAX_RETRIES)
#else
# define GC_INIT_CONF_MAX_RETRIES /* empty */
#endif
#if defined(GC_ALLOCD_BYTES_PER_FINALIZER) && !defined(CPPCHECK)
/* Set GC_allocd_bytes_per_finalizer to the desired value at start-up. */
# define GC_INIT_CONF_ALLOCD_BYTES_PER_FINALIZER \
GC_set_allocd_bytes_per_finalizer(GC_ALLOCD_BYTES_PER_FINALIZER)
#else
# define GC_INIT_CONF_ALLOCD_BYTES_PER_FINALIZER /* empty */
#endif
#if defined(GC_FREE_SPACE_DIVISOR) && !defined(CPPCHECK)
/* Set GC_free_space_divisor to the desired value at start-up */
# define GC_INIT_CONF_FREE_SPACE_DIVISOR \
GC_set_free_space_divisor(GC_FREE_SPACE_DIVISOR)
#else
# define GC_INIT_CONF_FREE_SPACE_DIVISOR /* empty */
#endif
#if defined(GC_FULL_FREQ) && !defined(CPPCHECK)
/* Set GC_full_freq to the desired value at start-up */
# define GC_INIT_CONF_FULL_FREQ GC_set_full_freq(GC_FULL_FREQ)
#else
# define GC_INIT_CONF_FULL_FREQ /* empty */
#endif
#if defined(GC_TIME_LIMIT) && !defined(CPPCHECK)
/* Set GC_time_limit (in ms) to the desired value at start-up. */
# define GC_INIT_CONF_TIME_LIMIT GC_set_time_limit(GC_TIME_LIMIT)
#else
# define GC_INIT_CONF_TIME_LIMIT /* empty */
#endif
#if defined(GC_MARKERS) && defined(GC_THREADS) && !defined(CPPCHECK)
/* Set the number of marker threads (including the initiating */
/* one) to the desired value at start-up. */
# define GC_INIT_CONF_MARKERS GC_set_markers_count(GC_MARKERS)
#else
# define GC_INIT_CONF_MARKERS /* empty */
#endif
#if defined(GC_SIG_SUSPEND) && defined(GC_THREADS) && !defined(CPPCHECK)
# define GC_INIT_CONF_SUSPEND_SIGNAL GC_set_suspend_signal(GC_SIG_SUSPEND)
#else
# define GC_INIT_CONF_SUSPEND_SIGNAL /* empty */
#endif
#if defined(GC_SIG_THR_RESTART) && defined(GC_THREADS) && !defined(CPPCHECK)
# define GC_INIT_CONF_THR_RESTART_SIGNAL \
GC_set_thr_restart_signal(GC_SIG_THR_RESTART)
#else
# define GC_INIT_CONF_THR_RESTART_SIGNAL /* empty */
#endif
#if defined(GC_MAXIMUM_HEAP_SIZE) && !defined(CPPCHECK)
/* Limit the heap size to the desired value (useful for debugging). */
/* The limit could be overridden either at the program start-up by */
/* the similar environment variable or anytime later by the */
/* corresponding API function call. */
# define GC_INIT_CONF_MAXIMUM_HEAP_SIZE \
GC_set_max_heap_size(GC_MAXIMUM_HEAP_SIZE)
#else
# define GC_INIT_CONF_MAXIMUM_HEAP_SIZE /* empty */
#endif
#ifdef GC_IGNORE_WARN
/* Turn off all warnings at start-up (after GC initialization) */
# define GC_INIT_CONF_IGNORE_WARN GC_set_warn_proc(GC_ignore_warn_proc)
#else
# define GC_INIT_CONF_IGNORE_WARN /* empty */
#endif
#if defined(GC_INITIAL_HEAP_SIZE) && !defined(CPPCHECK)
/* Set heap size to the desired value at start-up */
# define GC_INIT_CONF_INITIAL_HEAP_SIZE \
{ size_t heap_size = GC_get_heap_size(); \
if (heap_size < (GC_INITIAL_HEAP_SIZE)) \
(void)GC_expand_hp((GC_INITIAL_HEAP_SIZE) - heap_size); }
#else
# define GC_INIT_CONF_INITIAL_HEAP_SIZE /* empty */
#endif
/* Portable clients should call this at the program start-up. More */
/* over, some platforms require this call to be done strictly from the */
/* primordial thread. Multiple invocations are harmless. */
#define GC_INIT() { GC_INIT_CONF_DONT_EXPAND; /* pre-init */ \
GC_INIT_CONF_FORCE_UNMAP_ON_GCOLLECT; \
GC_INIT_CONF_MAX_RETRIES; \
GC_INIT_CONF_ALLOCD_BYTES_PER_FINALIZER; \
GC_INIT_CONF_FREE_SPACE_DIVISOR; \
GC_INIT_CONF_FULL_FREQ; \
GC_INIT_CONF_TIME_LIMIT; \
GC_INIT_CONF_MARKERS; \
GC_INIT_CONF_SUSPEND_SIGNAL; \
GC_INIT_CONF_THR_RESTART_SIGNAL; \
GC_INIT_CONF_MAXIMUM_HEAP_SIZE; \
GC_init(); /* real GC initialization */ \
GC_INIT_CONF_ROOTS; /* post-init */ \
GC_INIT_CONF_IGNORE_WARN; \
GC_INIT_CONF_INITIAL_HEAP_SIZE; }
/* win32s may not free all resources on process exit. */
/* This explicitly deallocates the heap. Defined only for Windows. */
GC_API void GC_CALL GC_win32_free_heap(void);
#if defined(__SYMBIAN32__)
void GC_init_global_static_roots(void);
#endif
#if defined(_AMIGA) && !defined(GC_AMIGA_MAKINGLIB)
/* Allocation really goes through GC_amiga_allocwrapper_do. */
void *GC_amiga_realloc(void *, size_t);
# define GC_realloc(a,b) GC_amiga_realloc(a,b)
void GC_amiga_set_toany(void (*)(void));
extern int GC_amiga_free_space_divisor_inc;
extern void *(*GC_amiga_allocwrapper_do)(size_t, void *(GC_CALL *)(size_t));
# define GC_malloc(a) \
(*GC_amiga_allocwrapper_do)(a,GC_malloc)
# define GC_malloc_atomic(a) \
(*GC_amiga_allocwrapper_do)(a,GC_malloc_atomic)
# define GC_malloc_uncollectable(a) \
(*GC_amiga_allocwrapper_do)(a,GC_malloc_uncollectable)
# define GC_malloc_atomic_uncollectable(a) \
(*GC_amiga_allocwrapper_do)(a,GC_malloc_atomic_uncollectable)
# define GC_malloc_ignore_off_page(a) \
(*GC_amiga_allocwrapper_do)(a,GC_malloc_ignore_off_page)
# define GC_malloc_atomic_ignore_off_page(a) \
(*GC_amiga_allocwrapper_do)(a,GC_malloc_atomic_ignore_off_page)
#endif /* _AMIGA && !GC_AMIGA_MAKINGLIB */
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* GC_H */
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