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/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
* Copyright 1996-1999 by Silicon Graphics. All rights reserved.
* Copyright 1999 by Hewlett-Packard Company. All rights reserved.
* Copyright (C) 2007 Free Software Foundation, Inc
*
* 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.
* If you are using Solaris threads, look at the end of this file.
* Everything else is best ignored unless you encounter performance
* problems.
*/
#ifndef _GC_H
# define _GC_H
# include "gc_config_macros.h"
# ifdef __cplusplus
extern "C" {
# endif
/* Define word and signed_word to be unsigned and signed types of the */
/* size as char * or void *. There seems to be no way to do this */
/* even semi-portably. The following is probably no better/worse */
/* than almost anything else. */
/* The ANSI standard suggests that size_t and ptr_diff_t might be */
/* better choices. But those had incorrect definitions on some older */
/* systems. Notably "typedef int size_t" is WRONG. */
#ifndef _WIN64
typedef unsigned long GC_word;
typedef long GC_signed_word;
#else
/* Win64 isn't really supported yet, but this is the first step. And */
/* it might cause error messages to show up in more plausible places. */
/* This needs basetsd.h, which is included by windows.h. */
typedef unsigned long long GC_word;
typedef long long GC_signed_word;
#endif
/* Public read-only variables */
GC_API GC_word GC_gc_no;/* Counter incremented per collection. */
/* Includes empty GCs at startup. */
GC_API int GC_parallel; /* GC is parallelized for performance on */
/* multiprocessors. Currently set only */
/* implicitly if collector is built with */
/* -DPARALLEL_MARK and if either: */
/* Env variable GC_NPROC is set to > 1, or */
/* GC_NPROC is not set and this is an MP. */
/* If GC_parallel is set, incremental */
/* collection is only partially functional, */
/* and may not be desirable. */
/* Public R/W variables */
GC_API void * (*GC_oom_fn) (size_t bytes_requested);
/* When there is insufficient memory to satisfy */
/* an allocation request, we return */
/* (*GC_oom_fn)(). By default this just */
/* returns 0. */
/* If it returns, it must return 0 or a valid */
/* pointer to a previously allocated heap */
/* object. */
GC_API int GC_find_leak;
/* 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. */
GC_API int GC_all_interior_pointers;
/* Arrange for pointers to object interiors to */
/* be recognized as valid. May not be changed */
/* after GC initialization. */
/* Initial value is determined by */
/* -DALL_INTERIOR_POINTERS. */
/* Unless DONT_ADD_BYTE_AT_END is defined, this */
/* also affects whether sizes are increased by */
/* at least a byte to allow "off the end" */
/* pointer recognition. */
/* MUST BE 0 or 1. */
GC_API 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. */
GC_API int GC_java_finalization;
/* Mark objects reachable from finalizable */
/* objects in a separate postpass. This makes */
/* it a bit safer to use non-topologically- */
/* ordered finalization. Default value is */
/* determined by JAVA_FINALIZATION macro. */
/* Enables register_finalizer_unreachable to */
/* work correctly. */
GC_API void (* GC_finalizer_notifier)(void);
/* 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. */
GC_API int GC_dont_gc; /* != 0 ==> Dont collect. In versions 6.2a1+, */
/* this overrides explicit GC_gcollect() calls. */
/* 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. */
GC_API int GC_dont_expand;
/* Dont expand heap unless explicitly requested */
/* or forced to. */
GC_API int GC_use_entire_heap;
/* Causes the nonincremental collector to use the */
/* entire heap before collecting. This was the only */
/* option for GC versions < 5.0. This sometimes */
/* results in more large block fragmentation, since */
/* very larg 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 int GC_full_freq; /* Number of partial collections between */
/* full collections. Matters only if */
/* GC_incremental is set. */
/* Full collections are also triggered if */
/* the collector detects a substantial */
/* increase in the number of in-use heap */
/* blocks. Values in the tens are now */
/* perfectly reasonable, unlike for */
/* earlier GC versions. */
GC_API 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. */
GC_API int GC_no_dls;
/* Don't register dynamic library data segments. */
/* Wizards only. Should be used only if the */
/* application explicitly registers all roots. */
/* In Microsoft Windows environments, this will */
/* usually also prevent registration of the */
/* main data segment as part of the root set. */
GC_API 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. */
/* Initially, GC_free_space_divisor = 3. */
/* Increasing its value will use less space */
/* but more collection time. Decreasing it */
/* will appreciably decrease collection time */
/* at the expense of space. */
GC_API GC_word GC_max_retries;
/* The maximum number of GCs attempted before */
/* reporting out of memory after heap */
/* expansion fails. Initially 0. */
GC_API char *GC_stackbottom; /* Cool end 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 multithreaded code, this is the */
/* cold end of the stack for the */
/* primordial thread. */
GC_API int GC_dont_precollect; /* Don't collect as part of */
/* 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. */
GC_API unsigned long GC_time_limit;
/* If incremental collection is enabled, */
/* We try to terminate collections */
/* after this many milliseconds. Not a */
/* hard time bound. Setting this to */
/* GC_TIME_UNLIMITED will essentially */
/* disable incremental collection while */
/* leaving generational collection */
/* enabled. */
# define GC_TIME_UNLIMITED 999999
/* Setting GC_time_limit to this value */
/* will disable the "pause time exceeded"*/
/* tests. */
/* Public procedures */
/* Initialize the collector. This is only required when using thread-local
* allocation, since unlike the regular allocation routines, GC_local_malloc
* is not self-initializing. If you use GC_local_malloc you should arrange
* to call this somehow (e.g. from a constructor) before doing any allocation.
* For win32 threads, it needs to be called explicitly.
*/
GC_API void GC_init(void);
/*
* general purpose allocation routines, with roughly malloc calling conv.
* The atomic versions promise that no relevant pointers are contained
* in the object. The nonatomic versions guarantee that the new object
* is cleared. GC_malloc_stubborn promises that no changes to the object
* will occur after GC_end_stubborn_change has been called on the
* result of GC_malloc_stubborn. GC_malloc_uncollectable allocates an object
* that is scanned for pointers to collectable objects, but is not itself
* collectable. 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.
*
* Note that the GC_malloc_stubborn support is stubbed out by default
* starting in 6.0. GC_malloc_stubborn is an alias for GC_malloc unless
* the collector is built with STUBBORN_ALLOC defined.
*/
GC_API void * GC_malloc(size_t size_in_bytes);
GC_API void * GC_malloc_atomic(size_t size_in_bytes);
GC_API char * GC_strdup (const char *str);
GC_API void * GC_malloc_uncollectable(size_t size_in_bytes);
GC_API void * GC_malloc_stubborn(size_t size_in_bytes);
/* The following is only defined if the library has been suitably */
/* compiled: */
GC_API void * GC_malloc_atomic_uncollectable(size_t size_in_bytes);
/* Explicitly deallocate an object. Dangerous if used incorrectly. */
/* Requires a pointer to the base of an object. */
/* If the argument is stubborn, it should not be changeable when freed. */
/* An object should not be enable for finalization when it is */
/* explicitly deallocated. */
/* GC_free(0) is a no-op, as required by ANSI C for free. */
GC_API void GC_free(void * object_addr);
/*
* Stubborn objects may be changed only if the collector is explicitly informed.
* The collector is implicitly informed of coming change when such
* an object is first allocated. The following routines inform the
* collector that an object will no longer be changed, or that it will
* once again be changed. Only nonNIL pointer stores into the object
* are considered to be changes. The argument to GC_end_stubborn_change
* must be exacly the value returned by GC_malloc_stubborn or passed to
* GC_change_stubborn. (In the second case it may be an interior pointer
* within 512 bytes of the beginning of the objects.)
* There is a performance penalty for allowing more than
* one stubborn object to be changed at once, but it is acceptable to
* do so. The same applies to dropping stubborn objects that are still
* changeable.
*/
GC_API void GC_change_stubborn(void *);
GC_API void GC_end_stubborn_change(void *);
/* 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 bas 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_base(void * displaced_pointer);
/* Given a pointer to the base of an object, return its size in bytes. */
/* The returned size may be slightly larger than what was originally */
/* requested. */
GC_API size_t GC_size(void * object_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. */
/* If the argument is stubborn, the result will have changes enabled. */
/* It is an error to have changes enabled for the original object. */
/* Follows ANSI comventions for NULL old_object. */
GC_API void * GC_realloc(void * old_object, size_t new_size_in_bytes);
/* Explicitly increase the heap size. */
/* Returns 0 on failure, 1 on success. */
GC_API int 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. */
GC_API void 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. */
GC_API void GC_exclude_static_roots(void * low_address,
void * high_address_plus_1);
/* Clear the set of root segments. Wizards only. */
GC_API void GC_clear_roots(void);
/* Add a root segment. Wizards only. */
GC_API void GC_add_roots(void * low_address, void * high_address_plus_1);
/* Remove a root segment. Wizards only. */
GC_API void 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_register_displacement(size_t n);
/* The following version should be used if any debugging allocation is */
/* being done. */
GC_API void GC_debug_register_displacement(size_t n);
/* Explicitly trigger a full, world-stop collection. */
GC_API void GC_gcollect(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. 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. */
/* Return 0 if the collection was aborted, 1 if it succeeded. */
typedef int (* GC_stop_func)(void);
GC_API int GC_try_to_collect(GC_stop_func stop_func);
/* Return the number of bytes in the heap. Excludes collector private */
/* data structures. Includes empty blocks and fragmentation loss. */
/* Includes some pages that were allocated but never written. */
GC_API size_t GC_get_heap_size(void);
/* Return a lower bound on the number of free bytes in the heap. */
GC_API size_t GC_get_free_bytes(void);
/* Return the number of bytes allocated since the last collection. */
GC_API size_t GC_get_bytes_since_gc(void);
/* Return the total number of bytes allocated in this process. */
/* Never decreases, except due to wrapping. */
GC_API size_t GC_get_total_bytes(void);
/* Disable garbage collection. Even GC_gcollect calls will be */
/* ineffective. */
GC_API void GC_disable(void);
/* Reenable garbage collection. GC_disable() and GC_enable() calls */
/* nest. Garbage collection is enabled if the number of calls to both */
/* both functions is equal. */
GC_API void GC_enable(void);
/* Enable incremental/generational collection. */
/* Not advisable unless dirty bits are */
/* available or most heap objects are */
/* pointerfree(atomic) or immutable. */
/* Don't use in leak finding mode. */
/* Ignored if GC_dont_gc is true. */
/* Only the generational piece of this is */
/* functional if GC_parallel is TRUE */
/* or if GC_time_limit is GC_TIME_UNLIMITED. */
/* Causes GC_local_gcj_malloc() to revert to */
/* locked allocation. Must be called */
/* before any GC_local_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_enable_incremental(void);
/* Does incremental mode write-protect pages? Returns zero or */
/* more of the following, or'ed together: */
#define GC_PROTECTS_POINTER_HEAP 1 /* May protect non-atomic objs. */
#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
GC_API int GC_incremental_protection_needs(void);
/* Perform some garbage collection work, if appropriate. */
/* Return 0 if there is no more work to be done. */
/* 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. */
GC_API int 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 256 bytes 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 MS Windows system this is recommended */
/* for arrays likely to be larger than 100K 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 void * GC_malloc_ignore_off_page(size_t lb);
GC_API void * GC_malloc_atomic_ignore_off_page(size_t lb);
#if defined(__sgi) && !defined(__GNUC__) && _COMPILER_VERSION >= 720
# define GC_ADD_CALLER
# define GC_RETURN_ADDR (GC_word)__return_address
#endif
#if defined(__linux__) || defined(__GLIBC__)
# include <features.h>
# if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1 || __GLIBC__ > 2) \
&& !defined(__ia64__)
# ifndef GC_HAVE_BUILTIN_BACKTRACE
# define GC_HAVE_BUILTIN_BACKTRACE
# endif
# endif
# if defined(__i386__) || defined(__x86_64__)
# define GC_CAN_SAVE_CALL_STACKS
# endif
#endif
#if defined(_MSC_VER) && _MSC_VER >= 1200 /* version 12.0+ (MSVC 6.0+) */ \
&& !defined(_AMD64_)
# ifndef GC_HAVE_NO_BUILTIN_BACKTRACE
# define GC_HAVE_BUILTIN_BACKTRACE
# endif
#endif
#if defined(GC_HAVE_BUILTIN_BACKTRACE) && !defined(GC_CAN_SAVE_CALL_STACKS)
# define GC_CAN_SAVE_CALL_STACKS
#endif
#if defined(__sparc__)
# define GC_CAN_SAVE_CALL_STACKS
#endif
/* If we're on an a platform on which we can't save call stacks, but */
/* gcc is normally used, we go ahead and define GC_ADD_CALLER. */
/* We make this decision independent of whether gcc is actually being */
/* used, in order to keep the interface consistent, and allow mixing */
/* of compilers. */
/* This may also be desirable if it is possible but expensive to */
/* retrieve the call chain. */
#if (defined(__linux__) || defined(__NetBSD__) || defined(__OpenBSD__) \
|| defined(__FreeBSD__) || defined(__DragonFly__)) & !defined(GC_CAN_SAVE_CALL_STACKS)
# define GC_ADD_CALLER
# if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
/* gcc knows how to retrieve return address, but we don't know */
/* how to generate call stacks. */
# define GC_RETURN_ADDR (GC_word)__builtin_return_address(0)
# else
/* Just pass 0 for gcc compatibility. */
# define GC_RETURN_ADDR 0
# endif
#endif
#ifdef GC_ADD_CALLER
# define GC_EXTRAS GC_RETURN_ADDR, __FILE__, __LINE__
# define GC_EXTRA_PARAMS GC_word ra, const char * s, int i
#else
# define GC_EXTRAS __FILE__, __LINE__
# define GC_EXTRA_PARAMS const char * s, int i
#endif
/* Debugging (annotated) allocation. GC_gcollect will check */
/* objects allocated in this way for overwrites, etc. */
GC_API void * GC_debug_malloc(size_t size_in_bytes, GC_EXTRA_PARAMS);
GC_API void * GC_debug_malloc_atomic(size_t size_in_bytes, GC_EXTRA_PARAMS);
GC_API char * GC_debug_strdup(const char *str, GC_EXTRA_PARAMS);
GC_API void * GC_debug_malloc_uncollectable
(size_t size_in_bytes, GC_EXTRA_PARAMS);
GC_API void * GC_debug_malloc_stubborn
(size_t size_in_bytes, GC_EXTRA_PARAMS);
GC_API void * GC_debug_malloc_ignore_off_page
(size_t size_in_bytes, GC_EXTRA_PARAMS);
GC_API void * GC_debug_malloc_atomic_ignore_off_page
(size_t size_in_bytes, GC_EXTRA_PARAMS);
GC_API void GC_debug_free (void * object_addr);
GC_API void * GC_debug_realloc
(void * old_object, size_t new_size_in_bytes, GC_EXTRA_PARAMS);
GC_API void GC_debug_change_stubborn(void *);
GC_API void GC_debug_end_stubborn_change(void *);
/* 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 void * GC_debug_malloc_replacement (size_t size_in_bytes);
GC_API void * GC_debug_realloc_replacement
(void * object_addr, size_t size_in_bytes);
# ifdef GC_DEBUG
# define GC_MALLOC(sz) GC_debug_malloc(sz, GC_EXTRAS)
# define GC_MALLOC_ATOMIC(sz) GC_debug_malloc_atomic(sz, GC_EXTRAS)
# define GC_STRDUP(s) GC_debug_strdup((s), 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_REALLOC(old, sz) GC_debug_realloc(old, 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_MALLOC_STUBBORN(sz) GC_debug_malloc_stubborn(sz, GC_EXTRAS);
# define GC_CHANGE_STUBBORN(p) GC_debug_change_stubborn(p)
# define GC_END_STUBBORN_CHANGE(p) GC_debug_end_stubborn_change(p)
# define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
GC_general_register_disappearing_link(link, GC_base(obj))
# define GC_REGISTER_DISPLACEMENT(n) GC_debug_register_displacement(n)
# else
# define GC_MALLOC(sz) GC_malloc(sz)
# define GC_MALLOC_ATOMIC(sz) GC_malloc_atomic(sz)
# define GC_STRDUP(s) GC_strdup(s)
# 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_REALLOC(old, sz) GC_realloc(old, 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_MALLOC_STUBBORN(sz) GC_malloc_stubborn(sz)
# define GC_CHANGE_STUBBORN(p) GC_change_stubborn(p)
# define GC_END_STUBBORN_CHANGE(p) GC_end_stubborn_change(p)
# define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
GC_general_register_disappearing_link(link, obj)
# define GC_REGISTER_DISPLACEMENT(n) GC_register_displacement(n)
# endif
/* The following are included because they are often convenient, and */
/* reduce the chance for a misspecifed size argument. But calls may */
/* expand to something syntactically incorrect if t is a complicated */
/* type expression. */
# define GC_NEW(t) (t *)GC_MALLOC(sizeof (t))
# define GC_NEW_ATOMIC(t) (t *)GC_MALLOC_ATOMIC(sizeof (t))
# define GC_NEW_STUBBORN(t) (t *)GC_MALLOC_STUBBORN(sizeof (t))
# define GC_NEW_UNCOLLECTABLE(t) (t *)GC_MALLOC_UNCOLLECTABLE(sizeof (t))
/* 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_finalization_proc) (void * obj, void * client_data);
GC_API void GC_register_finalizer(void * obj, GC_finalization_proc fn,
void * cd, GC_finalization_proc *ofn,
void * *ocd);
GC_API void GC_debug_register_finalizer
(void * obj, GC_finalization_proc fn, void * cd,
GC_finalization_proc *ofn, void * *ocd);
/* 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. */
/* Finalization may be removed by passing 0 as fn. */
/* Finalizers are implicitly unregistered just before */
/* they are invoked. */
/* The old finalizer and client data are stored in */
/* *ofn and *ocd. */
/* Fn is never invoked on an accessible object, */
/* provided hidden pointers are converted to real */
/* pointers only if the allocation lock is held, 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 nonNULL starting address of an */
/* object allocated by GC_malloc or friends. */
/* Note that any garbage collectable 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_register_finalizer_ignore_self
(void * obj, GC_finalization_proc fn, void * cd,
GC_finalization_proc *ofn, void * *ocd);
GC_API void GC_debug_register_finalizer_ignore_self
(void * obj, GC_finalization_proc fn, void * cd,
GC_finalization_proc *ofn, void * *ocd);
/* 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_register_finalizer_no_order
(void * obj, GC_finalization_proc fn, void * cd,
GC_finalization_proc *ofn, void * *ocd);
GC_API void GC_debug_register_finalizer_no_order
(void * obj, GC_finalization_proc fn, void * cd,
GC_finalization_proc *ofn, void * *ocd);
/* 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_register_finalizer_unreachable
(void * obj, GC_finalization_proc fn, void * cd,
GC_finalization_proc *ofn, void * *ocd);
GC_API void GC_debug_register_finalizer_unreachable
(void * obj, GC_finalization_proc fn, void * cd,
GC_finalization_proc *ofn, void * *ocd);
/* 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_register_disappearing_link(void * * link );
/* 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 1 if link was already registered, 0 */
/* otherwise. */
/* Only exists for backward compatibility. See below: */
GC_API int GC_general_register_disappearing_link (void * * link, void * obj);
/* 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 */
/* holding a disguised pointer to obj. (A pointer */
/* inside an "atomic" object is effectively */
/* disguised.) In this way soft */
/* pointers are broken before any object */
/* reachable from them are finalized. Each link */
/* May be registered only once, i.e. with one obj */
/* value. This was added after a long email discussion */
/* with John Ellis. */
/* Obj must be a pointer to the first word of an object */
/* we allocated. It is unsafe to explicitly deallocate */
/* the object containing link. Explicitly deallocating */
/* obj may or may not cause link to eventually be */
/* cleared. */
/* This can be used to implement certain types of */
/* weak pointers. Note however that this generally */
/* requires that thje allocation lock is held (see */
/* GC_call_with_allock_lock() below) 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. */
GC_API int GC_unregister_disappearing_link (void * * link);
/* Returns 0 if link was not actually registered. */
/* Undoes a registration by either of the above two */
/* routines. */
/* Returns !=0 if GC_invoke_finalizers has something to do. */
GC_API int GC_should_invoke_finalizers(void);
GC_API int 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)
# define GC_reachable_here(ptr) \
__asm__ volatile(" " : : "X"(ptr) : "memory");
# else
GC_API void GC_noop1(GC_word x);
# define GC_reachable_here(ptr) GC_noop1((GC_word)(ptr));
#endif
/* GC_set_warn_proc can be used to redirect or filter warning messages. */
/* p may not be a NULL pointer. */
typedef void (*GC_warn_proc) (char *msg, GC_word arg);
GC_API GC_warn_proc GC_set_warn_proc(GC_warn_proc p);
/* Returns old warning procedure. */
GC_API GC_word GC_set_free_space_divisor(GC_word value);
/* Set free_space_divisor. See above for definition. */
/* Returns old value. */
/* 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. */
/* Note that putting pointers in atomic objects or in */
/* nonpointer slots of "typed" objects is equivalent to */
/* disguising them in this way, and may have other advantages. */
# if defined(I_HIDE_POINTERS) || defined(GC_I_HIDE_POINTERS)
typedef GC_word GC_hidden_pointer;
# define HIDE_POINTER(p) (~(GC_hidden_pointer)(p))
# define REVEAL_POINTER(p) ((void *)(HIDE_POINTER(p)))
/* Converting a hidden pointer to a real pointer requires verifying */
/* that the object still exists. This involves acquiring the */
/* allocator lock to avoid a race with the collector. */
# endif /* I_HIDE_POINTERS */
typedef void * (*GC_fn_type) (void * client_data);
GC_API void * GC_call_with_alloc_lock (GC_fn_type fn, void * client_data);
/* 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 base for thread */
/* stacks on all platforms. */
/* Structure representing the base of a thread stack. On most */
/* platforms this contains just a single address. */
struct GC_stack_base {
void * mem_base; /* Base of memory stack. */
# if defined(__ia64) || defined(__ia64__)
void * reg_base; /* Base of separate register stack. */
# endif
};
typedef void * (*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 base. And we */
/* implement it everywhere. */
void * GC_call_with_stack_base(GC_stack_base_func fn, void *arg);
/* Register the current thread, with the indicated stack base, as */
/* a new thread whose stack(s) should be traced by the GC. If a */
/* platform does not implicitly do so, 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. */
/* Return codes: */
#define GC_SUCCESS 0
#define GC_DUPLICATE 1 /* Was already registered. */
#define GC_NO_THREADS 2 /* No thread support in GC. */
#define GC_UNIMPLEMENTED 3 /* Not yet implemented on this platform. */
int GC_register_my_thread(struct GC_stack_base *);
/* Unregister the current 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. */
int GC_unregister_my_thread(void);
/* Attempt to fill in the GC_stack_base structure with the stack base */
/* 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. */
int GC_get_stack_base(struct GC_stack_base *);
/* 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. */
/* Check that p and q point to the same object. */
/* Fail conspicuously if they don't. */
/* Returns the first argument. */
/* Succeeds if neither p nor q points to the heap. */
/* May succeed if both p and q point to between heap objects. */
GC_API void * GC_same_obj (void * p, void * q);
/* 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_pre_incr (void * *p, size_t how_much);
GC_API void * GC_post_incr (void * *p, size_t how_much);
/* Check that p is visible */
/* to the collector as a possibly pointer containing location. */
/* If it isn't fail conspicuously. */
/* Returns the argument in all cases. May erroneously succeed */
/* in hard cases. (This 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 multithreaded worlds. */
GC_API void * 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. */
/* Fail conspicuously if this property does not hold. */
/* Uninteresting with GC_all_interior_pointers. */
/* Always returns its argument. */
GC_API void * 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. */
void GC_dump(void);
/* Safer, but slow, pointer addition. Probably useful mainly with */
/* a preprocessor. Useful only for heap pointers. */
#ifdef GC_DEBUG
# 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(&(x), (n)*sizeof(*x))
# define GC_POST_INCR2(x, type_of_result) \
((type_of_result)GC_post_incr(&(x), sizeof(*x))
# ifdef __GNUC__
# 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, n) \
GC_POST_INCR3(x, typeof(x))
# else
/* We can't do this right without typeof, which ANSI */
/* decided was not sufficiently useful. Repeatedly */
/* mentioning the arguments seems too dangerous to be */
/* useful. So does not casting the result. */
# define GC_PTR_ADD(x, n) ((x)+(n))
# endif
#else /* !GC_DEBUG */
# define GC_PTR_ADD3(x, n, type_of_result) ((x)+(n))
# define GC_PTR_ADD(x, n) ((x)+(n))
# define GC_PRE_INCR3(x, n, type_of_result) ((x) += (n))
# define GC_PRE_INCR(x, n) ((x) += (n))
# define GC_POST_INCR2(x, n, type_of_result) ((x)++)
# define GC_POST_INCR(x, n) ((x)++)
#endif
/* Safer assignment of a pointer to a nonstack location. */
#ifdef GC_DEBUG
# define GC_PTR_STORE(p, q) \
(*(void **)GC_is_visible(p) = GC_is_valid_displacement(q))
#else /* !GC_DEBUG */
# define GC_PTR_STORE(p, q) *((p) = (q))
#endif
/* Functions called to report pointer checking errors */
GC_API void (*GC_same_obj_print_proc) (void * p, void * q);
GC_API void (*GC_is_valid_displacement_print_proc) (void * p);
GC_API void (*GC_is_visible_print_proc) (void * p);
/* For pthread support, we generally need to intercept a number of */
/* thread library calls. We do that here by macro defining them. */
#if !defined(GC_USE_LD_WRAP) && \
(defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS))
# include "gc_pthread_redirects.h"
#endif
# if defined(PCR) || defined(GC_SOLARIS_THREADS) || \
defined(GC_PTHREADS) || defined(GC_WIN32_THREADS)
/* Any flavor of threads. */
/* This returns a list of objects, linked through their first */
/* word. Its use can greatly reduce lock contention problems, since */
/* the allocation lock can be acquired and released many fewer times. */
/* It is used internally by gc_local_alloc.h, which provides a simpler */
/* programming interface on Linux. */
void * GC_malloc_many(size_t lb);
#define GC_NEXT(p) (*(void * *)(p)) /* Retrieve the next element */
/* in returned list. */
extern void GC_thr_init(void); /* Needed for Solaris/X86 ?? */
#endif /* THREADS */
/* Register a callback to control the scanning of dynamic libraries.
When the GC scans the static data of a dynamic library, it will
first call a user-supplied routine with filename of the library and
the address and length of the memory region. This routine should
return nonzero if that region should be scanned. */
GC_API void
GC_register_has_static_roots_callback
(int (*callback)(const char *, void *, size_t));
#if defined(GC_WIN32_THREADS) && !defined(__CYGWIN32__) \
&& !defined(__CYGWIN__) \
&& !defined(GC_PTHREADS)
#ifdef __cplusplus
} /* Including windows.h in an extern "C" context no longer works. */
#endif
# include <windows.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* All threads must be created using GC_CreateThread or GC_beginthreadex,
* or must explicitly call GC_register_my_thread,
* so that they will be recorded in the thread table.
* For backwards compatibility, it is possible to build the GC
* with GC_DLL defined, and to call GC_use_DllMain().
* 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. (An explicit call
* to GC_unregister_my_thread() should also work, but risks unregistering
* the thread twice.)
*/
GC_API HANDLE WINAPI GC_CreateThread(
LPSECURITY_ATTRIBUTES lpThreadAttributes,
DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,
LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId );
GC_API uintptr_t GC_beginthreadex(
void *security, unsigned stack_size,
unsigned ( __stdcall *start_address )( void * ),
void *arglist, unsigned initflag, unsigned *thrdaddr);
GC_API void GC_endthreadex(unsigned retval);
GC_API void WINAPI GC_ExitThread(DWORD dwExitCode);
# if defined(_WIN32_WCE)
/*
* win32_threads.c implements the real WinMain, which will start a new thread
* to call GC_WinMain after initializing the garbage collector.
*/
GC_API int WINAPI GC_WinMain(
HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPWSTR lpCmdLine,
int nCmdShow );
# ifndef GC_BUILD
# define WinMain GC_WinMain
# endif
# endif /* defined(_WIN32_WCE) */
/*
* Use implicit thread registration via DllMain.
*/
GC_API void GC_use_DllMain(void);
# define CreateThread GC_CreateThread
# define ExitThread GC_ExitThread
# define _beginthreadex GC_beginthreadex
# define _endthreadex GC_endthreadex
# define _beginthread { > "Please use _beginthreadex instead of _beginthread" < }
#endif /* defined(GC_WIN32_THREADS) && !cygwin */
/*
* 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().
*/
#if defined(__CYGWIN32__) || defined (_AIX)
/*
* Similarly gnu-win32 DLLs need explicit initialization from
* the main program, as does AIX.
*/
# ifdef __CYGWIN32__
extern int _data_start__[];
extern int _data_end__[];
extern int _bss_start__[];
extern int _bss_end__[];
# define GC_MAX(x,y) ((x) > (y) ? (x) : (y))
# define GC_MIN(x,y) ((x) < (y) ? (x) : (y))
# define GC_DATASTART ((void *) GC_MIN(_data_start__, _bss_start__))
# define GC_DATAEND ((void *) GC_MAX(_data_end__, _bss_end__))
# if defined(GC_DLL)
# define GC_INIT() { GC_add_roots(GC_DATASTART, GC_DATAEND); \
GC_gcollect(); /* For blacklisting. */}
# else
/* Main program init not required */
# define GC_INIT() { GC_init(); }
# endif
# endif
# if defined(_AIX)
extern int _data[], _end[];
# define GC_DATASTART ((void *)((ulong)_data))
# define GC_DATAEND ((void *)((ulong)_end))
# define GC_INIT() { GC_add_roots(GC_DATASTART, GC_DATAEND); }
# endif
#else
# define GC_INIT() { GC_init(); }
#endif
#if !defined(_WIN32_WCE) \
&& ((defined(_MSDOS) || defined(_MSC_VER)) && (_M_IX86 >= 300) \
|| defined(_WIN32) && !defined(__CYGWIN32__) && !defined(__CYGWIN__))
/* win32S may not free all resources on process exit. */
/* This explicitly deallocates the heap. */
GC_API void GC_win32_free_heap ();
#endif
#if ( defined(_AMIGA) && !defined(GC_AMIGA_MAKINGLIB) )
/* Allocation really goes through GC_amiga_allocwrapper_do */
# include "gc_amiga_redirects.h"
#endif
#if defined(GC_REDIRECT_TO_LOCAL) && !defined(GC_LOCAL_ALLOC_H)
# include "gc_local_alloc.h"
#endif
#ifdef __cplusplus
} /* end of extern "C" */
#endif
#endif /* _GC_H */