/* * 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_version.h" /* Define version numbers here to allow test on build machine */ /* for cross-builds. Note that this defines the header */ /* version number, which may or may not match that of the */ /* dynamic library. GC_get_version() can be used to obtain */ /* the latter. */ #include "gc_config_macros.h" #ifdef __cplusplus extern "C" { #endif /* 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 ptrdiff_t might be */ /* better choices. But those had incorrect definitions on some older */ /* systems. Notably "typedef int size_t" is WRONG. */ #ifdef _WIN64 # ifdef __int64 typedef unsigned __int64 GC_word; typedef __int64 GC_signed_word; # else typedef unsigned long long GC_word; typedef long long GC_signed_word; # endif #else typedef unsigned long GC_word; typedef long GC_signed_word; #endif /* Get the GC library version. The returned value is in the form: */ /* ((version_major<<16) | (version_minor<<8) | alpha_version). */ GC_API unsigned GC_CALL GC_get_version(void); /* Public read-only variables */ /* The supplied getter functions are preferred for new code. */ GC_API GC_word GC_gc_no;/* Counter incremented per collection. */ /* Includes empty GCs at startup. */ GC_API GC_word GC_CALL GC_get_gc_no(void); /* GC_get_gc_no() uses no synchronization, so */ /* it requires GC_call_with_alloc_lock() to */ /* avoid data races on multiprocessors. */ GC_API int GC_parallel; /* GC is parallelized for performance on */ /* multiprocessors. Currently set only */ /* implicitly if collector is built with */ /* PARALLEL_MARK defined 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. */ GC_API int GC_CALL GC_get_parallel(void); /* Public R/W variables */ /* The supplied setter and getter functions are preferred for new code. */ typedef void * (GC_CALLBACK * GC_oom_func)(size_t /* bytes_requested */); GC_API GC_oom_func GC_oom_fn; /* When there is insufficient memory to satisfy */ /* an allocation request, we return */ /* (*GC_oom_fn)(size). By default this just */ /* returns NULL. */ /* If it returns, it must return 0 or a valid */ /* pointer to a previously allocated heap */ /* object. GC_oom_fn must not be 0. */ /* Both the supplied setter and the getter */ /* acquire the GC lock (to avoid data races). */ GC_API void GC_CALL GC_set_oom_fn(GC_oom_func); GC_API GC_oom_func GC_CALL GC_get_oom_fn(void); 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. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_find_leak(int); GC_API int GC_CALL GC_get_find_leak(void); 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. The initial value */ /* depends on whether the GC is built with */ /* ALL_INTERIOR_POINTERS macro defined or not. */ /* 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 void GC_CALL GC_set_all_interior_pointers(int); GC_API int GC_CALL GC_get_all_interior_pointers(void); 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. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_finalize_on_demand(int); GC_API int GC_CALL GC_get_finalize_on_demand(void); GC_API int GC_java_finalization; /* Mark objects reachable from finalizable */ /* objects in a separate post-pass. This makes */ /* it a bit safer to use non-topologically- */ /* ordered finalization. Default value is */ /* determined by JAVA_FINALIZATION macro. */ /* Enables register_finalizer_unreachable to */ /* work correctly. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_java_finalization(int); GC_API int GC_CALL GC_get_java_finalization(void); typedef void (GC_CALLBACK * GC_finalizer_notifier_proc)(void); GC_API GC_finalizer_notifier_proc GC_finalizer_notifier; /* Invoked by the collector when there are */ /* objects to be finalized. Invoked at most */ /* once per GC cycle. Never invoked unless */ /* GC_finalize_on_demand is set. */ /* Typically this will notify a finalization */ /* thread, which will call GC_invoke_finalizers */ /* in response. May be 0 (means no notifier). */ /* Both the supplied setter and the getter */ /* acquire the GC lock (to avoid data races). */ GC_API void GC_CALL GC_set_finalizer_notifier(GC_finalizer_notifier_proc); GC_API GC_finalizer_notifier_proc GC_CALL GC_get_finalizer_notifier(void); GC_API int GC_dont_gc; /* != 0 ==> Don't 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; /* Don't expand the heap unless explicitly */ /* requested or forced to. The setter and */ /* getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_dont_expand(int); GC_API int GC_CALL GC_get_dont_expand(void); GC_API int GC_use_entire_heap; /* Causes the non-incremental 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 large blocks will tend to get broken up */ /* during each GC cycle. It is likely to result in a */ /* larger working set, but lower collection */ /* frequencies, and hence fewer instructions executed */ /* in the collector. */ GC_API 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. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_full_freq(int); GC_API int GC_CALL GC_get_full_freq(void); GC_API GC_word GC_non_gc_bytes; /* Bytes not considered candidates for */ /* collection. Used only to control scheduling */ /* of collections. Updated by */ /* GC_malloc_uncollectable and GC_free. */ /* Wizards only. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_non_gc_bytes(GC_word); GC_API GC_word GC_CALL GC_get_non_gc_bytes(void); GC_API 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. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_no_dls(int); GC_API int GC_CALL GC_get_no_dls(void); 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. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_free_space_divisor(GC_word); GC_API GC_word GC_CALL GC_get_free_space_divisor(void); GC_API GC_word GC_max_retries; /* The maximum number of GCs attempted before */ /* reporting out of memory after heap */ /* expansion fails. Initially 0. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_max_retries(GC_word); GC_API GC_word GC_CALL GC_get_max_retries(void); GC_API 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. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_dont_precollect(int); GC_API int GC_CALL GC_get_dont_precollect(void); 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. */ /* The setter and getter are unsynchronized, so */ /* GC_call_with_alloc_lock() is required to */ /* avoid data races (if the value is modified */ /* after the GC is put to multi-threaded mode). */ GC_API void GC_CALL GC_set_time_limit(unsigned long); GC_API unsigned long GC_CALL GC_get_time_limit(void); /* Public procedures */ /* Initialize the collector. Portable clients should call GC_INIT() */ /* from the main program instead. */ GC_API void GC_CALL 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 non-atomic 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 doesn't really exist */ /* anymore. MANUAL_VDB provides comparable functionality. */ GC_API void * GC_CALL GC_malloc(size_t /* size_in_bytes */) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API void * GC_CALL GC_malloc_atomic(size_t /* size_in_bytes */) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API char * GC_CALL GC_strdup(const char *) GC_ATTR_MALLOC; GC_API void * GC_CALL GC_malloc_uncollectable(size_t /* size_in_bytes */) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API void * GC_CALL GC_malloc_stubborn(size_t /* size_in_bytes */) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); /* GC_memalign() is not well tested. */ GC_API void * GC_CALL GC_memalign(size_t /* align */, size_t /* lb */) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(2); /* The following is only defined if the library has been suitably */ /* compiled: */ GC_API void * GC_CALL GC_malloc_atomic_uncollectable( size_t /* size_in_bytes */) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); /* 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 enabled 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_CALL GC_free(void *); /* 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 non-NULL pointer stores */ /* into the object are considered to be changes. The argument to */ /* GC_end_stubborn_change must be exactly 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_CALL GC_change_stubborn(void *); GC_API void GC_CALL 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_CALL 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_CALL GC_size(const 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 conventions for NULL old_object. */ GC_API void * GC_CALL GC_realloc(void * /* old_object */, size_t /* new_size_in_bytes */) /* 'realloc' attr */ GC_ATTR_ALLOC_SIZE(2); /* Explicitly increase the heap size. */ /* Returns 0 on failure, 1 on success. */ GC_API int GC_CALL GC_expand_hp(size_t /* number_of_bytes */); /* Limit the heap size to n bytes. Useful when you're debugging, */ /* especially on systems that don't handle running out of memory well. */ /* n == 0 ==> unbounded. This is the default. */ GC_API void GC_CALL GC_set_max_heap_size(GC_word /* n */); /* Inform the collector that a certain section of statically allocated */ /* memory contains no pointers to garbage collected memory. Thus it */ /* need not be scanned. This is sometimes important if the application */ /* maps large read/write files into the address space, which could be */ /* mistaken for dynamic library data segments on some systems. */ /* The section (referred to by low_address) must be pointer-aligned. */ /* low_address must not be greater than high_address_plus_1. */ GC_API void GC_CALL GC_exclude_static_roots(void * /* low_address */, void * /* high_address_plus_1 */); /* Clear the set of root segments. Wizards only. */ GC_API void GC_CALL GC_clear_roots(void); /* Add a root segment. Wizards only. */ /* The segment (referred to by low_address) must be pointer-aligned. */ /* low_address must not be greater than high_address_plus_1. */ GC_API void GC_CALL GC_add_roots(void * /* low_address */, void * /* high_address_plus_1 */); /* Remove a root segment. Wizards only. */ /* May be unimplemented on some platforms. */ GC_API void GC_CALL GC_remove_roots(void * /* low_address */, void * /* high_address_plus_1 */); /* Add a displacement to the set of those considered valid by the */ /* collector. GC_register_displacement(n) means that if p was returned */ /* by GC_malloc, then (char *)p + n will be considered to be a valid */ /* pointer to p. N must be small and less than the size of p. */ /* (All pointers to the interior of objects from the stack are */ /* considered valid in any case. This applies to heap objects and */ /* static data.) */ /* Preferably, this should be called before any other GC procedures. */ /* Calling it later adds to the probability of excess memory */ /* retention. */ /* This is a no-op if the collector has recognition of */ /* arbitrary interior pointers enabled, which is now the default. */ GC_API void GC_CALL GC_register_displacement(size_t /* n */); /* The following version should be used if any debugging allocation is */ /* being done. */ GC_API void GC_CALL GC_debug_register_displacement(size_t /* n */); /* Explicitly trigger a full, world-stop collection. */ GC_API void GC_CALL GC_gcollect(void); /* Same as above but ignores the default stop_func setting and tries to */ /* unmap as much memory as possible (regardless of the corresponding */ /* switch setting). The recommended usage: on receiving a system */ /* low-memory event; before retrying a system call failed because of */ /* the system is running out of resources. */ GC_API void GC_CALL GC_gcollect_and_unmap(void); /* Trigger a full world-stopped collection. Abort the collection if */ /* and when stop_func returns a nonzero value. Stop_func will be */ /* called frequently, and should be reasonably fast. (stop_func is */ /* called with the allocation lock held and the world might be stopped; */ /* it's not allowed for stop_func to manipulate pointers to the garbage */ /* collected heap or call most of GC functions.) This works even */ /* if virtual dirty bits, and hence incremental collection is not */ /* available for this architecture. Collections can be aborted faster */ /* than normal pause times for incremental collection. However, */ /* aborted collections do no useful work; the next collection needs */ /* to start from the beginning. stop_func must not be 0. */ /* GC_try_to_collect() returns 0 if the collection was aborted (or the */ /* collections are disabled), 1 if it succeeded. */ typedef int (GC_CALLBACK * GC_stop_func)(void); GC_API int GC_CALL GC_try_to_collect(GC_stop_func /* stop_func */); /* Set and get the default stop_func. The default stop_func is used by */ /* GC_gcollect() and by implicitly trigged collections (except for the */ /* case when handling out of memory). Must not be 0. */ GC_API void GC_CALL GC_set_stop_func(GC_stop_func /* stop_func */); GC_API GC_stop_func GC_CALL GC_get_stop_func(void); /* Return the number of bytes in the heap. Excludes collector private */ /* data structures. Excludes the unmapped memory (retuned to the OS). */ /* Includes empty blocks and fragmentation loss. Includes some pages */ /* that were allocated but never written. */ GC_API size_t GC_CALL GC_get_heap_size(void); /* Return a lower bound on the number of free bytes in the heap */ /* (excluding the unmapped memory space). */ GC_API size_t GC_CALL GC_get_free_bytes(void); /* Return the size (in bytes) of the unmapped memory (which is returned */ /* to the OS but could be remapped back by the collector later unless */ /* the OS runs out of system/virtual memory). */ GC_API size_t GC_CALL GC_get_unmapped_bytes(void); /* Return the number of bytes allocated since the last collection. */ GC_API size_t GC_CALL 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_CALL GC_get_total_bytes(void); /* Disable garbage collection. Even GC_gcollect calls will be */ /* ineffective. */ GC_API void GC_CALL GC_disable(void); /* Re-enable 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_CALL GC_enable(void); /* Enable incremental/generational collection. Not advisable unless */ /* dirty bits are available or most heap objects are pointer-free */ /* (atomic) or immutable. Don't use in leak finding mode. Ignored if */ /* GC_dont_gc is true. Only the generational piece of this is */ /* functional if GC_parallel is TRUE or if GC_time_limit is */ /* GC_TIME_UNLIMITED. Causes thread-local variant of GC_gcj_malloc() */ /* to revert to locked allocation. Must be called before any such */ /* GC_gcj_malloc() calls. For best performance, should be called as */ /* early as possible. On some platforms, calling it later may have */ /* adverse effects. */ /* Safe to call before GC_INIT(). Includes a GC_init() call. */ GC_API void GC_CALL GC_enable_incremental(void); /* 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_CALL 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_CALL GC_collect_a_little(void); /* Allocate an object of size lb bytes. The client guarantees that */ /* as long as the object is live, it will be referenced by a pointer */ /* that points to somewhere within the first 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_CALL GC_malloc_ignore_off_page(size_t /* lb */) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API void * GC_CALL GC_malloc_atomic_ignore_off_page(size_t /* lb */) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); #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 # if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1 || __GLIBC__ > 2) \ && !defined(__ia64__) && !defined(__UCLIBC__) \ && !defined(GC_HAVE_BUILTIN_BACKTRACE) # define GC_HAVE_BUILTIN_BACKTRACE # 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_) && !defined(GC_HAVE_NO_BUILTIN_BACKTRACE) \ && !defined(_WIN32_WCE) && !defined(GC_HAVE_BUILTIN_BACKTRACE) # define GC_HAVE_BUILTIN_BACKTRACE #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_CALL GC_debug_malloc(size_t /* size_in_bytes */, GC_EXTRA_PARAMS) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API void * GC_CALL GC_debug_malloc_atomic(size_t /* size_in_bytes */, GC_EXTRA_PARAMS) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API char * GC_CALL GC_debug_strdup(const char *, GC_EXTRA_PARAMS) GC_ATTR_MALLOC; GC_API void * GC_CALL GC_debug_malloc_uncollectable( size_t /* size_in_bytes */, GC_EXTRA_PARAMS) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API void * GC_CALL GC_debug_malloc_stubborn(size_t /* size_in_bytes */, GC_EXTRA_PARAMS) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API void * GC_CALL GC_debug_malloc_ignore_off_page( size_t /* size_in_bytes */, GC_EXTRA_PARAMS) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API void * GC_CALL GC_debug_malloc_atomic_ignore_off_page( size_t /* size_in_bytes */, GC_EXTRA_PARAMS) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API void GC_CALL GC_debug_free(void *); GC_API void * GC_CALL GC_debug_realloc(void * /* old_object */, size_t /* new_size_in_bytes */, GC_EXTRA_PARAMS) /* 'realloc' attr */ GC_ATTR_ALLOC_SIZE(2); GC_API void GC_CALL GC_debug_change_stubborn(void *); GC_API void GC_CALL 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_CALL GC_debug_malloc_replacement(size_t /* size_in_bytes */) GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1); GC_API void * GC_CALL GC_debug_realloc_replacement(void * /* object_addr */, size_t /* size_in_bytes */) /* 'realloc' attr */ GC_ATTR_ALLOC_SIZE(2); #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 misspecified 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_CALLBACK * GC_finalization_proc)(void * /* obj */, void * /* client_data */); GC_API void GC_CALL GC_register_finalizer(void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */, GC_finalization_proc * /* ofn */, void ** /* ocd */); GC_API void GC_CALL 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 when they are */ /* enqueued for finalization (i.e. become ready to be */ /* finalized). */ /* The old finalizer and client data are stored in */ /* *ofn and *ocd. (ofn and/or ocd may be NULL. */ /* The allocation lock is held while *ofn and *ocd are */ /* updated. In case of error (no memory to register */ /* new finalizer), *ofn and *ocd remain unchanged.) */ /* Fn is never invoked on an accessible object, */ /* provided hidden pointers are converted to real */ /* pointers only if the 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 starting address of an object */ /* allocated by GC_malloc or friends. Obj may also be */ /* NULL or point to something outside GC heap (in this */ /* case, fn is ignored, *ofn and *ocd are set to NULL). */ /* Note that any garbage 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_CALL GC_register_finalizer_ignore_self(void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */, GC_finalization_proc * /* ofn */, void ** /* ocd */); GC_API void GC_CALL GC_debug_register_finalizer_ignore_self(void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */, GC_finalization_proc * /* ofn */, void ** /* ocd */); /* Another version of the above. It ignores all cycles. */ /* It should probably only be used by Java implementations. */ /* Note that cd will still be viewed as accessible, even if it */ /* refers to the object itself. */ GC_API void GC_CALL GC_register_finalizer_no_order(void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */, GC_finalization_proc * /* ofn */, void ** /* ocd */); GC_API void GC_CALL 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_CALL GC_register_finalizer_unreachable(void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */, GC_finalization_proc * /* ofn */, void ** /* ocd */); GC_API void GC_CALL GC_debug_register_finalizer_unreachable(void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */, GC_finalization_proc * /* ofn */, void ** /* ocd */); #define GC_NO_MEMORY 2 /* Failure due to lack of memory. */ /* The following routine may be used to break cycles between */ /* finalizable objects, thus causing cyclic finalizable */ /* objects to be finalized in the correct order. Standard */ /* use involves calling GC_register_disappearing_link(&p), */ /* where p is a pointer that is not followed by finalization */ /* code, and should not be considered in determining */ /* finalization order. */ GC_API int GC_CALL GC_register_disappearing_link(void ** /* link */); /* Link should point to a field of a heap allocated */ /* object obj. *link will be cleared when obj is */ /* found to be inaccessible. This happens BEFORE any */ /* finalization code is invoked, and BEFORE any */ /* decisions about finalization order are made. */ /* This is useful in telling the finalizer that */ /* some pointers are not essential for proper */ /* finalization. This may avoid finalization cycles. */ /* Note that obj may be resurrected by another */ /* finalizer, and thus the clearing of *link may */ /* be visible to non-finalization code. */ /* There's an argument that an arbitrary action should */ /* be allowed here, instead of just clearing a pointer. */ /* But this causes problems if that action alters, or */ /* examines connectivity. Returns GC_DUPLICATE if link */ /* was already registered, GC_SUCCESS if registration */ /* succeeded, GC_NO_MEMORY if it failed for lack of */ /* memory, and GC_oom_fn did not handle the problem. */ /* Only exists for backward compatibility. See below: */ GC_API int GC_CALL GC_general_register_disappearing_link(void ** /* link */, 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, weak pointers are broken before any */ /* object reachable from them gets finalized. */ /* Each link may be registered only with one obj value, */ /* i.e. all objects but the last one (link registered */ /* with) are ignored. This was added after a long */ /* email discussion with John Ellis. */ /* link must be non-NULL (and be properly aligned). */ /* obj must be a pointer to the first word of an object */ /* allocated by GC_malloc or friends. It is unsafe to */ /* explicitly deallocate the object containing link. */ /* Explicit deallocation of obj may or may not cause */ /* link to eventually be cleared. */ /* This function can be used to implement certain types */ /* of weak pointers. Note, however, this generally */ /* requires that the allocation lock is held (see */ /* GC_call_with_alloc_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. Returns GC_SUCCESS if registration */ /* succeeded (a new link is registered), GC_DUPLICATE */ /* if link was already registered (with some object), */ /* GC_NO_MEMORY if registration failed for lack of */ /* memory (and GC_oom_fn did not handle the problem). */ GC_API int GC_CALL GC_unregister_disappearing_link(void ** /* link */); /* Undoes a registration by either of the above two */ /* routines. Returns 0 if link was not actually */ /* registered (otherwise returns 1). */ /* Returns !=0 if GC_invoke_finalizers has something to do. */ GC_API int GC_CALL GC_should_invoke_finalizers(void); GC_API int GC_CALL GC_invoke_finalizers(void); /* Run finalizers for all objects that are ready to */ /* be finalized. Return the number of finalizers */ /* that were run. Normally this is also called */ /* implicitly during some allocations. If */ /* GC_finalize_on_demand is nonzero, it must be called */ /* explicitly. */ /* Explicitly tell the collector that an object is reachable */ /* at a particular program point. This prevents the argument */ /* pointer from being optimized away, even it is otherwise no */ /* longer needed. It should have no visible effect in the */ /* absence of finalizers or disappearing links. But it may be */ /* needed to prevent finalizers from running while the */ /* associated external resource is still in use. */ /* The function is sometimes called keep_alive in other */ /* settings. */ #if defined(__GNUC__) && !defined(__INTEL_COMPILER) # define GC_reachable_here(ptr) \ __asm__ volatile(" " : : "X"(ptr) : "memory"); #else GC_API void GC_CALL GC_noop1(GC_word); # 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. Both the setter and the getter acquire */ /* the GC lock (to avoid data races). */ typedef void (GC_CALLBACK * GC_warn_proc)(char * /* msg */, GC_word /* arg */); GC_API void GC_CALL GC_set_warn_proc(GC_warn_proc /* p */); /* GC_get_warn_proc returns the current warn_proc. */ GC_API GC_warn_proc GC_CALL GC_get_warn_proc(void); /* GC_ignore_warn_proc may be used as an argument for */ /* GC_set_warn_proc() to suppress all warnings (unless */ /* statistics printing is turned on). */ GC_API void GC_CALLBACK GC_ignore_warn_proc(char *, GC_word); /* 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 */ /* The GC-prefixed symbols are preferred for new code (I_HIDE_POINTERS, */ /* HIDE_POINTER and REVEAL_POINTER remain for compatibility). */ #ifdef GC_I_HIDE_POINTERS # define GC_HIDE_POINTER(p) HIDE_POINTER(p) # define GC_REVEAL_POINTER(p) REVEAL_POINTER(p) #endif typedef void * (GC_CALLBACK * GC_fn_type)(void * /* client_data */); GC_API void * GC_CALL 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__) || defined(_M_IA64) void * reg_base; /* Base of separate register stack. */ # endif }; typedef void * (GC_CALLBACK * GC_stack_base_func)( struct GC_stack_base * /* sb */, void * /* arg */); /* Call a function with a stack base structure corresponding to */ /* somewhere in the GC_call_with_stack_base frame. This often can */ /* be used to provide a sufficiently accurate stack base. And we */ /* implement it everywhere. */ GC_API void * GC_CALL GC_call_with_stack_base(GC_stack_base_func /* fn */, void * /* arg */); #define GC_SUCCESS 0 #define GC_DUPLICATE 1 /* Was already registered. */ #define GC_NO_THREADS 2 /* No thread support in GC. */ /* GC_NO_THREADS is not returned by any GC func anymore. */ #define GC_UNIMPLEMENTED 3 /* Not yet implemented on this platform. */ /* GC_allow_register_threads(), GC_register_my_thread() and */ /* GC_unregister_my_thread() are exported only if the library has been */ /* compiled with threads support (GC_THREADS). */ /* Explicitly enable GC_register_my_thread() invocation. */ /* Done implicitly if a GC thread-creation function is called (or */ /* DllMain-based thread registration is enabled). Otherwise, it must */ /* be called from the main (or any previously registered) thread */ /* between the collector initialization and the first explicit */ /* registering of a thread (it should be called as late as possible). */ GC_API void GC_CALL GC_allow_register_threads(void); /* Register the current thread, with the indicated stack base, as */ /* a new thread whose stack(s) should be traced by the GC. If it */ /* is not implicitly called by the GC, this must be called before a */ /* thread can allocate garbage collected memory, or assign pointers */ /* to the garbage collected heap. Once registered, a thread will be */ /* stopped during garbage collections. */ /* This call must be previously enabled (see above). */ /* This should never be called from the main thread, where it is */ /* always done implicitly. This is normally done implicitly if GC_ */ /* functions are called to create the thread, e.g. by defining */ /* GC_THREADS and including gc.h (which redefines some system */ /* functions) before calling the system thread creation function. */ /* It is also always done implicitly under win32 with DllMain-based */ /* thread registration enabled. Except in this latter case, explicit */ /* calls are normally required for threads created by third-party */ /* libraries. */ GC_API int GC_CALL GC_register_my_thread(const struct GC_stack_base *); /* Unregister the current thread. Only an explicity registered thread */ /* (i.e. for which GC_register_my_thread() returns GC_SUCCESS) is */ /* allowed (and required) to call this function. The thread may no */ /* longer allocate garbage collected memory or manipulate pointers to */ /* the garbage collected heap after making this call. */ /* Specifically, if it wants to return or otherwise communicate a */ /* pointer to the garbage-collected heap to another thread, it must */ /* do this before calling GC_unregister_my_thread, most probably */ /* by saving it in a global data structure. Must not be called inside */ /* a GC callback function (except for GC_call_with_stack_base() one). */ GC_API int GC_CALL GC_unregister_my_thread(void); /* Wrapper for functions that are likely to block (or, at least, do not */ /* allocate garbage collected memory and/or manipulate pointers to the */ /* garbage collected heap) for an appreciable length of time. While fn */ /* is running, the collector is said to be in the "inactive" state for */ /* the current thread (this means that the thread is not suspended and */ /* the thread's stack frames "belonging" to the functions in the */ /* "inactive" state are not scanned during garbage collections). It is */ /* allowed for fn to call GC_call_with_gc_active() (even recursively), */ /* thus temporarily toggling the collector's state back to "active". */ GC_API void * GC_CALL GC_do_blocking(GC_fn_type /* fn */, void * /* client_data */); /* Call a function switching to the "active" state of the collector for */ /* the current thread (i.e. the user function is allowed to call any */ /* GC function and/or manipulate pointers to the garbage collected */ /* heap). GC_call_with_gc_active() has the functionality opposite to */ /* GC_do_blocking() one. It is assumed that the collector is already */ /* initialized and the current thread is registered. fn may toggle */ /* the collector thread's state temporarily to "inactive" one by using */ /* GC_do_blocking. GC_call_with_gc_active() often can be used to */ /* provide a sufficiently accurate stack base. */ GC_API void * GC_CALL GC_call_with_gc_active(GC_fn_type /* fn */, void * /* client_data */); /* 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. */ GC_API int GC_CALL 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_CALL 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_CALL GC_pre_incr(void **, ptrdiff_t /* how_much */); GC_API void * GC_CALL GC_post_incr(void **, ptrdiff_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_CALL GC_is_visible(void * /* p */); /* Check that if p is a pointer to a heap page, then it points to */ /* a valid displacement within a heap object. */ /* Fail conspicuously if this property does not hold. */ /* Uninteresting with GC_all_interior_pointers. */ /* Always returns its argument. */ GC_API void * GC_CALL GC_is_valid_displacement(void * /* p */); /* Explicitly dump the GC state. This is most often called from the */ /* debugger, or by setting the GC_DUMP_REGULARLY environment variable, */ /* but it may be useful to call it from client code during debugging. */ /* Defined only if the library has been compiled without NO_DEBUGGING. */ GC_API void GC_CALL GC_dump(void); /* Safer, but slow, pointer addition. Probably useful mainly with */ /* a preprocessor. Useful only for heap pointers. */ /* Only the macros without trailing digits are meant to be used */ /* by clients. These are designed to model the available C pointer */ /* arithmetic expressions. */ /* Even then, these are probably more useful as */ /* documentation than as part of the API. */ /* Note that GC_PTR_ADD evaluates the first argument more than once. */ #if defined(GC_DEBUG) && defined(__GNUC__) # define GC_PTR_ADD3(x, n, type_of_result) \ ((type_of_result)GC_same_obj((x)+(n), (x))) # define GC_PRE_INCR3(x, n, type_of_result) \ ((type_of_result)GC_pre_incr((void **)(&(x)), (n)*sizeof(*x))) # define GC_POST_INCR3(x, n, type_of_result) \ ((type_of_result)GC_post_incr((void **)(&(x)), (n)*sizeof(*x))) # define GC_PTR_ADD(x, n) GC_PTR_ADD3(x, n, typeof(x)) # define GC_PRE_INCR(x, n) GC_PRE_INCR3(x, n, typeof(x)) # define GC_POST_INCR(x) GC_POST_INCR3(x, 1, typeof(x)) # define GC_POST_DECR(x) GC_POST_INCR3(x, -1, typeof(x)) #else /* !GC_DEBUG || !__GNUC__ */ /* We can't do this right without typeof, which ANSI decided was not */ /* sufficiently useful. Without it we resort to the non-debug version. */ /* FIXME: This should eventually support C++0x decltype. */ # define GC_PTR_ADD(x, n) ((x)+(n)) # define GC_PRE_INCR(x, n) ((x) += (n)) # define GC_POST_INCR(x) ((x)++) # define GC_POST_DECR(x) ((x)--) #endif /* !GC_DEBUG || !__GNUC__ */ /* Safer assignment of a pointer to a non-stack location. */ #ifdef GC_DEBUG # define GC_PTR_STORE(p, q) \ (*(void **)GC_is_visible(p) = GC_is_valid_displacement(q)) #else # define GC_PTR_STORE(p, q) (*(p) = (q)) #endif /* Functions called to report pointer checking errors */ GC_API void (GC_CALLBACK * GC_same_obj_print_proc)(void * /* p */, void * /* q */); GC_API void (GC_CALLBACK * GC_is_valid_displacement_print_proc)(void *); GC_API void (GC_CALLBACK * GC_is_visible_print_proc)(void *); #ifdef GC_PTHREADS /* For pthread support, we generally need to intercept a number of */ /* thread library calls. We do that here by macro defining them. */ # include "gc_pthread_redirects.h" #endif /* 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. */ /* Exported only if the library has been compiled with threads support. */ GC_API void * GC_CALL GC_malloc_many(size_t /* lb */); #define GC_NEXT(p) (*(void * *)(p)) /* Retrieve the next element */ /* in returned list. */ /* A filter function to control the scanning of dynamic libraries. */ /* If implemented, called by GC before registering a dynamic library */ /* (discovered by GC) section as a static data root (called only as */ /* a last reason not to register). The filename of the library, the */ /* address and the length of the memory region (section) are passed. */ /* This routine should return nonzero if that region should be scanned. */ /* Always called with the allocation lock held. Depending on the */ /* platform, might be called with the "world" stopped. */ typedef int (GC_CALLBACK * GC_has_static_roots_func)( const char * /* dlpi_name */, void * /* section_start */, size_t /* section_size */); /* Register a new callback (a user-supplied filter) to control the */ /* scanning of dynamic libraries. Replaces any previously registered */ /* callback. May be 0 (means no filtering). May be unused on some */ /* platforms (if the filtering is unimplemented or inappropriate). */ GC_API void GC_CALL GC_register_has_static_roots_callback( GC_has_static_roots_func); #if defined(GC_WIN32_THREADS) && !defined(GC_PTHREADS) # ifndef GC_NO_THREAD_DECLS # ifdef __cplusplus } /* Including windows.h in an extern "C" context no longer works. */ # endif # if !defined(_WIN32_WCE) && !defined(__CEGCC__) # include /* For _beginthreadex, _endthreadex */ # endif # include # ifdef __cplusplus extern "C" { # endif # ifdef GC_UNDERSCORE_STDCALL /* Explicitly prefix exported/imported WINAPI (__stdcall) symbols */ /* with '_' (underscore). Might be useful if MinGW/x86 is used. */ # define GC_CreateThread _GC_CreateThread # define GC_ExitThread _GC_ExitThread # endif /* All threads must be created using GC_CreateThread or */ /* GC_beginthreadex, or must explicitly call GC_register_my_thread */ /* (and call GC_unregister_my_thread before thread termination), so */ /* that they will be recorded in the thread table. For backward */ /* compatibility, it is possible to build the GC with GC_DLL */ /* defined, and to call GC_use_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. */ GC_API HANDLE WINAPI GC_CreateThread( LPSECURITY_ATTRIBUTES /* lpThreadAttributes */, DWORD /* dwStackSize */, LPTHREAD_START_ROUTINE /* lpStartAddress */, LPVOID /* lpParameter */, DWORD /* dwCreationFlags */, LPDWORD /* lpThreadId */); GC_API void WINAPI GC_ExitThread(DWORD /* dwExitCode */); # if !defined(_WIN32_WCE) && !defined(__CEGCC__) # if !defined(_UINTPTR_T) && !defined(_UINTPTR_T_DEFINED) \ && !defined(UINTPTR_MAX) typedef GC_word GC_uintptr_t; # else typedef uintptr_t GC_uintptr_t; # endif GC_API GC_uintptr_t GC_CALL GC_beginthreadex( void * /* security */, unsigned /* stack_size */, unsigned (__stdcall *)(void *), void * /* arglist */, unsigned /* initflag */, unsigned * /* thrdaddr */); GC_API void GC_CALL GC_endthreadex(unsigned /* retval */); # endif /* !_WIN32_WCE */ # endif /* !GC_NO_THREAD_DECLS */ # ifdef GC_WINMAIN_REDIRECT /* win32_threads.c implements the real WinMain(), which will start */ /* a new thread to call GC_WinMain() after initializing the garbage */ /* collector. */ # define WinMain GC_WinMain # endif /* Use implicit thread registration via DllMain. Deprecated. Must */ /* be called before GC_INIT() and other GC routines. Should be */ /* avoided if GC_beginthreadex() or GC_CreateThread() could be called */ /* instead. */ GC_API void GC_CALL GC_use_DllMain(void); # ifndef GC_NO_THREAD_REDIRECTS # define CreateThread GC_CreateThread # define ExitThread GC_ExitThread # undef _beginthreadex # define _beginthreadex GC_beginthreadex # undef _endthreadex # define _endthreadex GC_endthreadex /* #define _beginthread { > "Please use _beginthreadex instead of _beginthread" < } */ # endif /* !GC_NO_THREAD_REDIRECTS */ #endif /* GC_WIN32_THREADS */ /* Public setter and getter for switching "unmap as much as possible" */ /* mode on(1) and off(0). Has no effect unless unmapping is turned on. */ /* Has no effect on implicitly-initiated garbage collections. Initial */ /* value is controlled by GC_FORCE_UNMAP_ON_GCOLLECT. */ GC_API void GC_CALL GC_set_force_unmap_on_gcollect(int); GC_API int GC_CALL GC_get_force_unmap_on_gcollect(void); /* Fully portable code should call GC_INIT() from the main program */ /* before making any other GC_ calls. On most platforms this is a */ /* no-op and the collector self-initializes. But a number of */ /* platforms make that too hard. */ /* A GC_INIT call is required if the collector is built with */ /* THREAD_LOCAL_ALLOC defined and the initial allocation call is not */ /* to GC_malloc() or GC_malloc_atomic(). */ #ifdef __CYGWIN32__ /* Similarly gnu-win32 DLLs need explicit initialization from the */ /* main program, as does AIX. */ extern int _data_start__[], _data_end__[], _bss_start__[], _bss_end__[]; # define GC_DATASTART (_data_start__ < _bss_start__ ? \ (void *)_data_start__ : (void *)_bss_start__) # define GC_DATAEND (_data_end__ > _bss_end__ ? \ (void *)_data_end__ : (void *)_bss_end__) # define GC_INIT_CONF_ROOTS GC_add_roots(GC_DATASTART, GC_DATAEND); \ GC_gcollect() /* For blacklisting. */ /* Required at least if GC is in dll. And doesn't hurt. */ #elif defined(_AIX) extern int _data[], _end[]; # define GC_DATASTART ((void *)((ulong)_data)) # define GC_DATAEND ((void *)((ulong)_end)) # define GC_INIT_CONF_ROOTS GC_add_roots(GC_DATASTART, GC_DATAEND) #else # define GC_INIT_CONF_ROOTS /* empty */ #endif #ifdef GC_DONT_EXPAND /* Set GC_dont_expand to TRUE at start-up */ # define GC_INIT_CONF_DONT_EXPAND GC_set_dont_expand(1) #else # define GC_INIT_CONF_DONT_EXPAND /* empty */ #endif #ifdef GC_FORCE_UNMAP_ON_GCOLLECT /* Turn on "unmap as much as possible on explicit GC" mode at start-up */ # define GC_INIT_CONF_FORCE_UNMAP_ON_GCOLLECT \ GC_set_force_unmap_on_gcollect(1) #else # define GC_INIT_CONF_FORCE_UNMAP_ON_GCOLLECT /* empty */ #endif #ifdef GC_MAX_RETRIES /* Set GC_max_retries to the desired value at start-up */ # define GC_INIT_CONF_MAX_RETRIES GC_set_max_retries(GC_MAX_RETRIES) #else # define GC_INIT_CONF_MAX_RETRIES /* empty */ #endif #ifdef GC_FREE_SPACE_DIVISOR /* Set GC_free_space_divisor to the desired value at start-up */ # define GC_INIT_CONF_FREE_SPACE_DIVISOR \ GC_set_free_space_divisor(GC_FREE_SPACE_DIVISOR) #else # define GC_INIT_CONF_FREE_SPACE_DIVISOR /* empty */ #endif #ifdef GC_FULL_FREQ /* Set GC_full_freq to the desired value at start-up */ # define GC_INIT_CONF_FULL_FREQ GC_set_full_freq(GC_FULL_FREQ) #else # define GC_INIT_CONF_FULL_FREQ /* empty */ #endif #ifdef GC_TIME_LIMIT /* Set GC_time_limit to the desired value at start-up */ # define GC_INIT_CONF_TIME_LIMIT GC_set_time_limit(GC_TIME_LIMIT) #else # define GC_INIT_CONF_TIME_LIMIT /* empty */ #endif #ifdef GC_MAXIMUM_HEAP_SIZE /* Limit the heap size to the desired value (useful for debugging). */ /* The limit could be overridden either at the program start-up by */ /* the similar environment variable or anytime later by the */ /* corresponding API function call. */ # define GC_INIT_CONF_MAXIMUM_HEAP_SIZE \ GC_set_max_heap_size(GC_MAXIMUM_HEAP_SIZE) #else # define GC_INIT_CONF_MAXIMUM_HEAP_SIZE /* empty */ #endif #ifdef GC_IGNORE_WARN /* Turn off all warnings at start-up (after GC initialization) */ # define GC_INIT_CONF_IGNORE_WARN GC_set_warn_proc(GC_ignore_warn_proc) #else # define GC_INIT_CONF_IGNORE_WARN /* empty */ #endif #ifdef GC_INITIAL_HEAP_SIZE /* Set heap size to the desired value at start-up */ # define GC_INIT_CONF_INITIAL_HEAP_SIZE \ { size_t heap_size = GC_get_heap_size(); \ if (heap_size < (GC_INITIAL_HEAP_SIZE)) \ (void)GC_expand_hp((GC_INITIAL_HEAP_SIZE) - heap_size); } #else # define GC_INIT_CONF_INITIAL_HEAP_SIZE /* empty */ #endif #define GC_INIT() { GC_INIT_CONF_DONT_EXPAND; /* pre-init */ \ GC_INIT_CONF_FORCE_UNMAP_ON_GCOLLECT; \ GC_INIT_CONF_MAX_RETRIES; \ GC_INIT_CONF_FREE_SPACE_DIVISOR; \ GC_INIT_CONF_FULL_FREQ; \ GC_INIT_CONF_TIME_LIMIT; \ GC_INIT_CONF_MAXIMUM_HEAP_SIZE; \ GC_init(); /* real GC initialization */ \ GC_INIT_CONF_ROOTS; /* post-init */ \ GC_INIT_CONF_IGNORE_WARN; \ GC_INIT_CONF_INITIAL_HEAP_SIZE; } /* win32S may not free all resources on process exit. */ /* This explicitly deallocates the heap. */ GC_API void GC_CALL GC_win32_free_heap(void); #if defined(_AMIGA) && !defined(GC_AMIGA_MAKINGLIB) /* Allocation really goes through GC_amiga_allocwrapper_do */ # include "gc_amiga_redirects.h" #endif /* * GC_REDIRECT_TO_LOCAL is now redundant; * that's the default with THREAD_LOCAL_ALLOC. */ #ifdef __cplusplus } /* end of extern "C" */ #endif #endif /* GC_H */