| /* |
| * 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. |
| * |
| * 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(__MINGW32__) && defined(WIN32_THREADS) |
| # ifdef GC_BUILD |
| # define GC_API __declspec(dllexport) |
| # else |
| # define GC_API __declspec(dllimport) |
| # endif |
| #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; |
| # define GC_CONST const |
| # else |
| # define GC_PROTO(args) () |
| typedef char * GC_PTR; |
| # define GC_CONST |
| # 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_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_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_finalize_on_demand; |
| /* If nonzero, finalizers will only be run in */ |
| /* response to an eplit 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. */ |
| |
| 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_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. */ |
| |
| 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)); |
| |
| /* 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 a lower bound on the number of free bytes in the heap. */ |
| GC_API size_t GC_get_free_bytes 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, GC_CONST char * s, int i |
| #else |
| # define GC_EXTRAS __FILE__, __LINE__ |
| # define GC_EXTRA_PARAMS GC_CONST char * s, int i |
| #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_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \ |
| GC_debug_register_finalizer_no_order(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_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \ |
| GC_register_finalizer_no_order(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)); |
| |
| /* Another version of the above. It ignores all cycles. */ |
| /* It should probably only be used by Java implementations. */ |
| GC_API void GC_register_finalizer_no_order |
| 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_no_order |
| 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)); |
| |
| /* Returns !=0 if GC_invoke_finalizers has something to do. */ |
| GC_API int GC_should_invoke_finalizers GC_PROTO((void)); |
| |
| 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 */ |
| /* GC-finalize_on_demand is nonzero, 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(USE_LD_WRAP) && \ |
| (defined(IRIX_THREADS) || defined(LINUX_THREADS) || defined(HPUX_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 |
| # define dlopen GC_dlopen |
| |
| #endif /* xxxxx_THREADS */ |
| |
| # if defined(PCR) || defined(SOLARIS_THREADS) || defined(WIN32_THREADS) || \ |
| defined(IRIX_THREADS) || defined(LINUX_THREADS) || \ |
| defined(IRIX_JDK_THREADS) || defined(HPUX_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. */ |
| /* lb must be large enough to hold the pointer field. */ |
| 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 */ |
