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gecko-dev/gc/boehm/gc.h
beard%netscape.com e7aa503dfd added GC_remove_roots.
1999-09-30 05:14:39 +00:00

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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 by Silicon Graphics. All rights reserved.
*
* 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
# define __GC
# include <stddef.h>
#if defined(__CYGWIN32__) && defined(GC_USE_DLL)
#include "libgc_globals.h"
#endif
#if defined(_MSC_VER) && defined(_DLL)
# ifdef GC_BUILD
# define GC_API __declspec(dllexport)
# else
# define GC_API __declspec(dllimport)
# endif
#endif
#if defined(__WATCOMC__) && defined(GC_DLL)
# ifdef GC_BUILD
# define GC_API extern __declspec(dllexport)
# else
# define GC_API extern __declspec(dllimport)
# endif
#endif
#ifndef GC_API
#define GC_API extern
#endif
# if defined(__STDC__) || defined(__cplusplus)
# define GC_PROTO(args) args
typedef void * GC_PTR;
# else
# define GC_PROTO(args) ()
typedef char * GC_PTR;
# endif
# 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 appear to have incorrect definitions */
/* on may systems. Notably "typedef int size_t" seems to be both */
/* frequent and WRONG. */
typedef unsigned long GC_word;
typedef long GC_signed_word;
/* Public read-only variables */
GC_API GC_word GC_gc_no;/* Counter incremented per collection. */
/* Includes empty GCs at startup. */
/* Public R/W variables */
GC_API GC_PTR (*GC_oom_fn) GC_PROTO((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_quiet; /* Disable statistics output. Only matters if */
/* collector has been compiled with statistics */
/* enabled. This involves a performance cost, */
/* and is thus not the default. */
GC_API int GC_dont_gc; /* Dont collect unless explicitly requested, e.g. */
/* because it's not safe. */
GC_API int GC_dont_expand;
/* Dont expand heap unless explicitly requested */
/* or forced to. */
GC_API int GC_full_freq; /* Number of partial collections between */
/* full collections. Matters only if */
/* GC_incremental is set. */
GC_API GC_word GC_non_gc_bytes;
/* Bytes not considered candidates for collection. */
/* Used only to control scheduling of collections. */
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 the heap size plus */
/* a rough estimate of the root set size. */
/* Initially, GC_free_space_divisor = 4. */
/* Increasing its value will use less space */
/* but more collection time. Decreasing it */
/* will appreciably decrease collection time */
/* at the expense of space. */
/* GC_free_space_divisor = 1 will effectively */
/* disable collections. */
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. */
/* Public procedures */
/*
* 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. GC_malloc_uncollectable and GC_free called on the resulting
* object implicitly update GC_non_gc_bytes appropriately.
*/
GC_API GC_PTR GC_malloc GC_PROTO((size_t size_in_bytes));
GC_API GC_PTR GC_malloc_atomic GC_PROTO((size_t size_in_bytes));
GC_API GC_PTR GC_malloc_uncollectable GC_PROTO((size_t size_in_bytes));
GC_API GC_PTR GC_malloc_stubborn GC_PROTO((size_t size_in_bytes));
/* The following is only defined if the library has been suitably */
/* compiled: */
GC_API GC_PTR GC_malloc_atomic_uncollectable GC_PROTO((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 GC_PROTO((GC_PTR 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 GC_PROTO((GC_PTR));
GC_API void GC_end_stubborn_change GC_PROTO((GC_PTR));
/* Return a pointer to the base (lowest address) of an object given */
/* a pointer to a location within the object. */
/* Return 0 if displaced_pointer doesn't point to within a valid */
/* object. */
GC_API GC_PTR GC_base GC_PROTO((GC_PTR 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 GC_PROTO((GC_PTR 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 GC_PTR GC_realloc
GC_PROTO((GC_PTR 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 GC_PROTO((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_PROTO((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 GC_PROTO((GC_PTR start, GC_PTR finish));
/* Clear the set of root segments. Wizards only. */
GC_API void GC_clear_roots GC_PROTO((void));
/* Add a root segment. Wizards only. */
GC_API void GC_add_roots GC_PROTO((char * low_address,
char * high_address_plus_1));
/* Remove a root segment. Wizards only. */
GC_API void GC_remove_roots GC_PROTO((char * low_address,
char * 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 n. 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 was compiled with recognition of */
/* arbitrary interior pointers enabled, which is now the default. */
GC_API void GC_register_displacement GC_PROTO((GC_word n));
/* The following version should be used if any debugging allocation is */
/* being done. */
GC_API void GC_debug_register_displacement GC_PROTO((GC_word n));
/* Explicitly trigger a full, world-stop collection. */
GC_API void GC_gcollect GC_PROTO((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) GC_PROTO((void));
GC_API int GC_try_to_collect GC_PROTO((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 GC_PROTO((void));
/* Return the number of bytes allocated since the last collection. */
GC_API size_t GC_get_bytes_since_gc GC_PROTO((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. */
GC_API void GC_enable_incremental GC_PROTO((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 GC_PROTO((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 GC_PTR GC_malloc_ignore_off_page GC_PROTO((size_t lb));
GC_API GC_PTR GC_malloc_atomic_ignore_off_page GC_PROTO((size_t lb));
#if defined(__sgi) && !defined(__GNUC__) && _COMPILER_VERSION >= 720
# define GC_ADD_CALLER
# define GC_RETURN_ADDR (GC_word)__return_address
#endif
#ifdef GC_ADD_CALLER
# define GC_EXTRAS GC_RETURN_ADDR, __FILE__, __LINE__
# define GC_EXTRA_PARAMS GC_word ra, char * descr_string, int descr_int
#else
# define GC_EXTRAS __FILE__, __LINE__
# define GC_EXTRA_PARAMS char * descr_string, int descr_int
#endif
/* Debugging (annotated) allocation. GC_gcollect will check */
/* objects allocated in this way for overwrites, etc. */
GC_API GC_PTR GC_debug_malloc
GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
GC_API GC_PTR GC_debug_malloc_atomic
GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
GC_API GC_PTR GC_debug_malloc_uncollectable
GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
GC_API GC_PTR GC_debug_malloc_stubborn
GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
GC_API void GC_debug_free GC_PROTO((GC_PTR object_addr));
GC_API GC_PTR GC_debug_realloc
GC_PROTO((GC_PTR old_object, size_t new_size_in_bytes,
GC_EXTRA_PARAMS));
GC_API void GC_debug_change_stubborn GC_PROTO((GC_PTR));
GC_API void GC_debug_end_stubborn_change GC_PROTO((GC_PTR));
# 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_MALLOC_UNCOLLECTABLE(sz) GC_debug_malloc_uncollectable(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_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_MALLOC_UNCOLLECTABLE(sz) GC_malloc_uncollectable(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_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 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)
GC_PROTO((GC_PTR obj, GC_PTR client_data));
GC_API void GC_register_finalizer
GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
GC_finalization_proc *ofn, GC_PTR *ocd));
GC_API void GC_debug_register_finalizer
GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
GC_finalization_proc *ofn, GC_PTR *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. */
GC_API void GC_register_finalizer_ignore_self
GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
GC_finalization_proc *ofn, GC_PTR *ocd));
GC_API void GC_debug_register_finalizer_ignore_self
GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
GC_finalization_proc *ofn, GC_PTR *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 GC_PROTO((GC_PTR * /* 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
GC_PROTO((GC_PTR * /* link */, GC_PTR 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. */
GC_API int GC_unregister_disappearing_link GC_PROTO((GC_PTR * /* link */));
/* Returns 0 if link was not actually registered. */
/* Undoes a registration by either of the above two */
/* routines. */
/* Auxiliary fns to make finalization work correctly with displaced */
/* pointers introduced by the debugging allocators. */
GC_API GC_PTR GC_make_closure GC_PROTO((GC_finalization_proc fn, GC_PTR data));
GC_API void GC_debug_invoke_finalizer GC_PROTO((GC_PTR obj, GC_PTR data));
GC_API int GC_invoke_finalizers GC_PROTO((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 */
/* FINALIZE_ON_DEMAND is defined, it must be called */
/* explicitly. */
/* 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) GC_PROTO((char *msg, GC_word arg));
GC_API GC_warn_proc GC_set_warn_proc GC_PROTO((GC_warn_proc p));
/* Returns old warning procedure. */
/* The following is intended to be used by a higher level */
/* (e.g. cedar-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) ((GC_PTR)(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 GC_PTR (*GC_fn_type) GC_PROTO((GC_PTR client_data));
GC_API GC_PTR GC_call_with_alloc_lock
GC_PROTO((GC_fn_type fn, GC_PTR client_data));
/* 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 GC_PTR GC_same_obj GC_PROTO((GC_PTR p, GC_PTR 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 GC_PTR GC_pre_incr GC_PROTO((GC_PTR *p, size_t how_much));
GC_API GC_PTR GC_post_incr GC_PROTO((GC_PTR *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 GC_PTR GC_is_visible GC_PROTO((GC_PTR 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 ALL_INTERIOR_POINTERS. */
/* Always returns its argument. */
GC_API GC_PTR GC_is_valid_displacement GC_PROTO((GC_PTR p));
/* 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
# ifdef __STDC__
# define GC_PTR_STORE(p, q) \
(*(void **)GC_is_visible(p) = GC_is_valid_displacement(q))
# else
# define GC_PTR_STORE(p, q) \
(*(char **)GC_is_visible(p) = GC_is_valid_displacement(q))
# endif
#else /* !GC_DEBUG */
# define GC_PTR_STORE(p, q) *((p) = (q))
#endif
/* Fynctions called to report pointer checking errors */
GC_API void (*GC_same_obj_print_proc) GC_PROTO((GC_PTR p, GC_PTR q));
GC_API void (*GC_is_valid_displacement_print_proc)
GC_PROTO((GC_PTR p));
GC_API void (*GC_is_visible_print_proc)
GC_PROTO((GC_PTR p));
#if defined(_SOLARIS_PTHREADS) && !defined(SOLARIS_THREADS)
# define SOLARIS_THREADS
#endif
#ifdef SOLARIS_THREADS
/* We need to intercept calls to many of the threads primitives, so */
/* that we can locate thread stacks and stop the world. */
/* Note also that the collector cannot see thread specific data. */
/* Thread specific data should generally consist of pointers to */
/* uncollectable objects, which are deallocated using the destructor */
/* facility in thr_keycreate. */
# include <thread.h>
# include <signal.h>
int GC_thr_create(void *stack_base, size_t stack_size,
void *(*start_routine)(void *), void *arg, long flags,
thread_t *new_thread);
int GC_thr_join(thread_t wait_for, thread_t *departed, void **status);
int GC_thr_suspend(thread_t target_thread);
int GC_thr_continue(thread_t target_thread);
void * GC_dlopen(const char *path, int mode);
# ifdef _SOLARIS_PTHREADS
# include <pthread.h>
extern int GC_pthread_create(pthread_t *new_thread,
const pthread_attr_t *attr,
void * (*thread_execp)(void *), void *arg);
extern int GC_pthread_join(pthread_t wait_for, void **status);
# undef thread_t
# define pthread_join GC_pthread_join
# define pthread_create GC_pthread_create
#endif
# define thr_create GC_thr_create
# define thr_join GC_thr_join
# define thr_suspend GC_thr_suspend
# define thr_continue GC_thr_continue
# define dlopen GC_dlopen
# endif /* SOLARIS_THREADS */
#if defined(IRIX_THREADS) || defined(LINUX_THREADS)
/* We treat these similarly. */
# include <pthread.h>
# include <signal.h>
int GC_pthread_create(pthread_t *new_thread,
const pthread_attr_t *attr,
void *(*start_routine)(void *), void *arg);
int GC_pthread_sigmask(int how, const sigset_t *set, sigset_t *oset);
int GC_pthread_join(pthread_t thread, void **retval);
# define pthread_create GC_pthread_create
# define pthread_sigmask GC_pthread_sigmask
# define pthread_join GC_pthread_join
#endif /* IRIX_THREADS || LINUX_THREADS */
# if defined(PCR) || defined(SOLARIS_THREADS) || defined(WIN32_THREADS) || \
defined(IRIX_THREADS) || defined(LINUX_THREADS) || \
defined(IRIX_JDK_THREADS)
/* Any flavor of threads except SRC_M3. */
/* 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. */
GC_PTR GC_malloc_many(size_t lb);
#define GC_NEXT(p) (*(GC_PTR *)(p)) /* Retrieve the next element */
/* in returned list. */
extern void GC_thr_init(); /* Needed for Solaris/X86 */
#endif /* THREADS && !SRC_M3 */
/*
* If you are planning on putting
* the collector in a SunOS 5 dynamic library, you need to call GC_INIT()
* from the statically loaded program section.
* This circumvents a Solaris 2.X (X<=4) linker bug.
*/
#if defined(sparc) || defined(__sparc)
# define GC_INIT() { extern end, etext; \
GC_noop(&end, &etext); }
#else
# if defined(__CYGWIN32__) && defined(GC_USE_DLL)
/*
* Similarly gnu-win32 DLLs need explicit initialization
*/
# define GC_INIT() { GC_add_roots(DATASTART, DATAEND); }
# else
# define GC_INIT()
# endif
#endif
#if (defined(_MSDOS) || defined(_MSC_VER)) && (_M_IX86 >= 300) \
|| defined(_WIN32)
/* win32S may not free all resources on process exit. */
/* This explicitly deallocates the heap. */
GC_API void GC_win32_free_heap ();
#endif
#ifdef __cplusplus
} /* end of extern "C" */
#endif
#endif /* _GC_H */
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