2 * boehm-gc.c: GC implementation using either the installed or included Boehm GC.
4 * Copyright 2001-2003 Ximian, Inc (http://www.ximian.com)
5 * Copyright 2004-2011 Novell, Inc (http://www.novell.com)
6 * Copyright 2011-2012 Xamarin, Inc (http://www.xamarin.com)
7 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
14 #define GC_I_HIDE_POINTERS
15 #include <mono/metadata/gc-internals.h>
16 #include <mono/metadata/mono-gc.h>
17 #include <mono/metadata/profiler-private.h>
18 #include <mono/metadata/class-internals.h>
19 #include <mono/metadata/method-builder.h>
20 #include <mono/metadata/opcodes.h>
21 #include <mono/metadata/domain-internals.h>
22 #include <mono/metadata/metadata-internals.h>
23 #include <mono/metadata/marshal.h>
24 #include <mono/metadata/runtime.h>
25 #include <mono/metadata/sgen-toggleref.h>
26 #include <mono/utils/atomic.h>
27 #include <mono/utils/mono-logger-internals.h>
28 #include <mono/utils/mono-memory-model.h>
29 #include <mono/utils/mono-time.h>
30 #include <mono/utils/mono-threads.h>
31 #include <mono/utils/dtrace.h>
32 #include <mono/utils/gc_wrapper.h>
33 #include <mono/utils/mono-os-mutex.h>
34 #include <mono/utils/mono-counters.h>
40 #define THREAD_LOCAL_ALLOC 1
41 #include "private/pthread_support.h"
43 #if defined(PLATFORM_MACOSX) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
44 void *pthread_get_stackaddr_np(pthread_t);
47 #define GC_NO_DESCRIPTOR ((gpointer)(0 | GC_DS_LENGTH))
48 /*Boehm max heap cannot be smaller than 16MB*/
49 #define MIN_BOEHM_MAX_HEAP_SIZE_IN_MB 16
50 #define MIN_BOEHM_MAX_HEAP_SIZE (MIN_BOEHM_MAX_HEAP_SIZE_IN_MB << 20)
52 static gboolean gc_initialized = FALSE;
53 static mono_mutex_t mono_gc_lock;
56 boehm_thread_register (MonoThreadInfo* info, void *baseptr);
58 boehm_thread_unregister (MonoThreadInfo *p);
60 register_test_toggleref_callback (void);
62 #define BOEHM_GC_BIT_FINALIZER_AWARE 1
63 static MonoGCFinalizerCallbacks fin_callbacks;
67 static mono_mutex_t handle_section;
68 #define lock_handles(handles) mono_os_mutex_lock (&handle_section)
69 #define unlock_handles(handles) mono_os_mutex_unlock (&handle_section)
76 guint slot_hint : 24; /* starting slot for search in bitmap */
77 /* 2^16 appdomains should be enough for everyone (though I know I'll regret this in 20 years) */
78 /* we alloc this only for weak refs, since we can get the domain directly in the other cases */
82 #define EMPTY_HANDLE_DATA(type) {NULL, NULL, 0, (type), 0, NULL}
84 /* weak and weak-track arrays will be allocated in malloc memory
86 static HandleData gc_handles [] = {
87 EMPTY_HANDLE_DATA (HANDLE_WEAK),
88 EMPTY_HANDLE_DATA (HANDLE_WEAK_TRACK),
89 EMPTY_HANDLE_DATA (HANDLE_NORMAL),
90 EMPTY_HANDLE_DATA (HANDLE_PINNED)
94 mono_gc_warning (char *msg, GC_word arg)
96 mono_trace (G_LOG_LEVEL_WARNING, MONO_TRACE_GC, msg, (unsigned long)arg);
100 mono_gc_base_init (void)
102 MonoThreadInfoCallbacks cb;
109 mono_counters_init ();
112 * Handle the case when we are called from a thread different from the main thread,
114 * FIXME: Move this to libgc where it belongs.
116 * we used to do this only when running on valgrind,
117 * but it happens also in other setups.
119 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK) && !defined(__native_client__)
124 pthread_getattr_np (pthread_self (), &attr);
125 pthread_attr_getstack (&attr, &sstart, &size);
126 pthread_attr_destroy (&attr);
127 /*g_print ("stackbottom pth is: %p\n", (char*)sstart + size);*/
130 * The calculation above doesn't seem to work on ia64, also we need to set
131 * GC_register_stackbottom as well, but don't know how.
134 /* apparently with some linuxthreads implementations sstart can be NULL,
135 * fallback to the more imprecise method (bug# 78096).
138 GC_stackbottom = (char*)sstart + size;
141 gsize stack_bottom = (gsize)&dummy;
142 stack_bottom += 4095;
143 stack_bottom &= ~4095;
144 GC_stackbottom = (char*)stack_bottom;
148 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
149 GC_stackbottom = (char*)pthread_get_stackaddr_np (pthread_self ());
150 #elif defined(__OpenBSD__)
151 # include <pthread_np.h>
156 rslt = pthread_stackseg_np(pthread_self(), &ss);
157 g_assert (rslt == 0);
159 GC_stackbottom = (char*)ss.ss_sp;
161 #elif defined(__native_client__)
162 /* Do nothing, GC_stackbottom is set correctly in libgc */
166 gsize stack_bottom = (gsize)&dummy;
167 stack_bottom += 4095;
168 stack_bottom &= ~4095;
169 /*g_print ("stackbottom is: %p\n", (char*)stack_bottom);*/
170 GC_stackbottom = (char*)stack_bottom;
174 #if !defined(PLATFORM_ANDROID)
175 /* If GC_no_dls is set to true, GC_find_limit is not called. This causes a seg fault on Android. */
179 if ((env = g_getenv ("MONO_GC_DEBUG"))) {
180 char **opts = g_strsplit (env, ",", -1);
181 for (char **ptr = opts; ptr && *ptr; ptr ++) {
183 if (!strcmp (opt, "do-not-finalize")) {
184 mono_do_not_finalize = 1;
185 } else if (!strcmp (opt, "log-finalizers")) {
194 GC_set_warn_proc (mono_gc_warning);
195 GC_finalize_on_demand = 1;
196 GC_finalizer_notifier = mono_gc_finalize_notify;
198 GC_init_gcj_malloc (5, NULL);
199 GC_allow_register_threads ();
201 if ((env = g_getenv ("MONO_GC_PARAMS"))) {
202 char **ptr, **opts = g_strsplit (env, ",", -1);
203 for (ptr = opts; *ptr; ++ptr) {
205 if (g_str_has_prefix (opt, "max-heap-size=")) {
208 opt = strchr (opt, '=') + 1;
209 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
210 if (max_heap < MIN_BOEHM_MAX_HEAP_SIZE) {
211 fprintf (stderr, "max-heap-size must be at least %dMb.\n", MIN_BOEHM_MAX_HEAP_SIZE_IN_MB);
214 GC_set_max_heap_size (max_heap);
216 fprintf (stderr, "max-heap-size must be an integer.\n");
220 } else if (g_str_has_prefix (opt, "toggleref-test")) {
221 register_test_toggleref_callback ();
224 /* Could be a parameter for sgen */
226 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
227 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
235 memset (&cb, 0, sizeof (cb));
236 cb.thread_register = boehm_thread_register;
237 cb.thread_unregister = boehm_thread_unregister;
238 cb.mono_method_is_critical = (gboolean (*)(void *))mono_runtime_is_critical_method;
240 mono_threads_init (&cb, sizeof (MonoThreadInfo));
241 mono_os_mutex_init (&mono_gc_lock);
242 mono_os_mutex_init_recursive (&handle_section);
244 mono_thread_info_attach (&dummy);
246 mono_gc_enable_events ();
248 MONO_GC_REGISTER_ROOT_FIXED (gc_handles [HANDLE_NORMAL].entries, MONO_ROOT_SOURCE_GC_HANDLE, "gc handles table");
249 MONO_GC_REGISTER_ROOT_FIXED (gc_handles [HANDLE_PINNED].entries, MONO_ROOT_SOURCE_GC_HANDLE, "gc handles table");
251 gc_initialized = TRUE;
255 mono_gc_base_cleanup (void)
257 GC_finalizer_notifier = NULL;
262 * @generation: GC generation identifier
264 * Perform a garbage collection for the given generation, higher numbers
265 * mean usually older objects. Collecting a high-numbered generation
266 * implies collecting also the lower-numbered generations.
267 * The maximum value for @generation can be retrieved with a call to
268 * mono_gc_max_generation(), so this function is usually called as:
270 * mono_gc_collect (mono_gc_max_generation ());
273 mono_gc_collect (int generation)
275 #ifndef DISABLE_PERFCOUNTERS
276 mono_perfcounters->gc_induced++;
282 * mono_gc_max_generation:
284 * Get the maximum generation number used by the current garbage
285 * collector. The value will be 0 for the Boehm collector, 1 or more
286 * for the generational collectors.
288 * Returns: the maximum generation number.
291 mono_gc_max_generation (void)
297 * mono_gc_get_generation:
298 * @object: a managed object
300 * Get the garbage collector's generation that @object belongs to.
301 * Use this has a hint only.
303 * Returns: a garbage collector generation number
306 mono_gc_get_generation (MonoObject *object)
312 * mono_gc_collection_count:
313 * @generation: a GC generation number
315 * Get how many times a garbage collection has been performed
316 * for the given @generation number.
318 * Returns: the number of garbage collections
321 mono_gc_collection_count (int generation)
327 * mono_gc_add_memory_pressure:
328 * @value: amount of bytes
330 * Adjust the garbage collector's view of how many bytes of memory
331 * are indirectly referenced by managed objects (for example unmanaged
332 * memory holding image or other binary data).
333 * This is a hint only to the garbage collector algorithm.
334 * Note that negative amounts of @value will decrease the memory
338 mono_gc_add_memory_pressure (gint64 value)
343 * mono_gc_get_used_size:
345 * Get the approximate amount of memory used by managed objects.
347 * Returns: the amount of memory used in bytes
350 mono_gc_get_used_size (void)
352 return GC_get_heap_size () - GC_get_free_bytes ();
356 * mono_gc_get_heap_size:
358 * Get the amount of memory used by the garbage collector.
360 * Returns: the size of the heap in bytes
363 mono_gc_get_heap_size (void)
365 return GC_get_heap_size ();
369 mono_gc_is_gc_thread (void)
371 return GC_thread_is_registered ();
375 mono_gc_register_thread (void *baseptr)
377 return mono_thread_info_attach (baseptr) != NULL;
381 boehm_thread_register (MonoThreadInfo* info, void *baseptr)
383 struct GC_stack_base sb;
386 /* TODO: use GC_get_stack_base instead of baseptr. */
387 sb.mem_base = baseptr;
388 res = GC_register_my_thread (&sb);
389 if (res == GC_UNIMPLEMENTED)
390 return NULL; /* Cannot happen with GC v7+. */
395 boehm_thread_unregister (MonoThreadInfo *p)
397 MonoNativeThreadId tid;
399 tid = mono_thread_info_get_tid (p);
401 if (p->runtime_thread)
402 mono_threads_add_joinable_thread ((gpointer)tid);
406 mono_object_is_alive (MonoObject* o)
408 return GC_is_marked ((ptr_t)o);
412 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
417 static gint64 gc_start_time;
420 on_gc_notification (GC_EventType event)
422 MonoGCEvent e = (MonoGCEvent)event;
425 case MONO_GC_EVENT_PRE_STOP_WORLD:
426 MONO_GC_WORLD_STOP_BEGIN ();
427 mono_thread_info_suspend_lock ();
430 case MONO_GC_EVENT_POST_STOP_WORLD:
431 MONO_GC_WORLD_STOP_END ();
434 case MONO_GC_EVENT_PRE_START_WORLD:
435 MONO_GC_WORLD_RESTART_BEGIN (1);
438 case MONO_GC_EVENT_POST_START_WORLD:
439 MONO_GC_WORLD_RESTART_END (1);
440 mono_thread_info_suspend_unlock ();
443 case MONO_GC_EVENT_START:
445 #ifndef DISABLE_PERFCOUNTERS
446 if (mono_perfcounters)
447 mono_perfcounters->gc_collections0++;
449 gc_stats.major_gc_count ++;
450 gc_start_time = mono_100ns_ticks ();
453 case MONO_GC_EVENT_END:
455 #if defined(ENABLE_DTRACE) && defined(__sun__)
456 /* This works around a dtrace -G problem on Solaris.
457 Limit its actual use to when the probe is enabled. */
458 if (MONO_GC_END_ENABLED ())
462 #ifndef DISABLE_PERFCOUNTERS
463 if (mono_perfcounters) {
464 guint64 heap_size = GC_get_heap_size ();
465 guint64 used_size = heap_size - GC_get_free_bytes ();
466 mono_perfcounters->gc_total_bytes = used_size;
467 mono_perfcounters->gc_committed_bytes = heap_size;
468 mono_perfcounters->gc_reserved_bytes = heap_size;
469 mono_perfcounters->gc_gen0size = heap_size;
472 gc_stats.major_gc_time += mono_100ns_ticks () - gc_start_time;
473 mono_trace_message (MONO_TRACE_GC, "gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
479 mono_profiler_gc_event (e, 0);
483 on_gc_heap_resize (size_t new_size)
485 guint64 heap_size = GC_get_heap_size ();
486 #ifndef DISABLE_PERFCOUNTERS
487 if (mono_perfcounters) {
488 mono_perfcounters->gc_committed_bytes = heap_size;
489 mono_perfcounters->gc_reserved_bytes = heap_size;
490 mono_perfcounters->gc_gen0size = heap_size;
493 mono_profiler_gc_heap_resize (new_size);
497 mono_gc_enable_events (void)
499 GC_set_on_collection_event (on_gc_notification);
500 GC_on_heap_resize = on_gc_heap_resize;
503 static gboolean alloc_events = FALSE;
506 mono_gc_enable_alloc_events (void)
512 mono_gc_register_root (char *start, size_t size, void *descr, MonoGCRootSource source, const char *msg)
514 /* for some strange reason, they want one extra byte on the end */
515 GC_add_roots (start, start + size + 1);
521 mono_gc_deregister_root (char* addr)
524 /* FIXME: libgc doesn't define this work win32 for some reason */
525 /* FIXME: No size info */
526 GC_remove_roots (addr, addr + sizeof (gpointer) + 1);
531 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
533 /* libgc requires that we use HIDE_POINTER... */
534 *link_addr = (void*)HIDE_POINTER (obj);
536 GC_REGISTER_LONG_LINK (link_addr, obj);
538 GC_GENERAL_REGISTER_DISAPPEARING_LINK (link_addr, obj);
542 mono_gc_weak_link_remove (void **link_addr, gboolean track)
545 GC_unregister_long_link (link_addr);
547 GC_unregister_disappearing_link (link_addr);
552 reveal_link (gpointer link_addr)
554 void **link_a = (void **)link_addr;
555 return REVEAL_POINTER (*link_a);
559 mono_gc_weak_link_get (void **link_addr)
561 MonoObject *obj = (MonoObject *)GC_call_with_alloc_lock (reveal_link, link_addr);
562 if (obj == (MonoObject *) -1)
568 mono_gc_make_descr_for_string (gsize *bitmap, int numbits)
570 return mono_gc_make_descr_from_bitmap (bitmap, numbits);
574 mono_gc_make_descr_for_object (gsize *bitmap, int numbits, size_t obj_size)
576 return mono_gc_make_descr_from_bitmap (bitmap, numbits);
580 mono_gc_make_descr_for_array (int vector, gsize *elem_bitmap, int numbits, size_t elem_size)
582 /* libgc has no usable support for arrays... */
583 return GC_NO_DESCRIPTOR;
587 mono_gc_make_descr_from_bitmap (gsize *bitmap, int numbits)
589 /* It seems there are issues when the bitmap doesn't fit: play it safe */
591 return GC_NO_DESCRIPTOR;
593 return (gpointer)GC_make_descriptor ((GC_bitmap)bitmap, numbits);
597 mono_gc_make_root_descr_all_refs (int numbits)
603 mono_gc_alloc_fixed (size_t size, void *descr, MonoGCRootSource source, const char *msg)
605 /* To help track down typed allocation bugs */
609 if (count == atoi (g_getenv ("COUNT2")))
611 if (count > atoi (g_getenv ("COUNT2")))
612 return GC_MALLOC (size);
616 return GC_MALLOC_EXPLICITLY_TYPED (size, (GC_descr)descr);
618 return GC_MALLOC (size);
622 mono_gc_free_fixed (void* addr)
627 mono_gc_alloc_obj (MonoVTable *vtable, size_t size)
631 if (!vtable->klass->has_references) {
632 obj = (MonoObject *)GC_MALLOC_ATOMIC (size);
633 if (G_UNLIKELY (!obj))
636 obj->vtable = vtable;
637 obj->synchronisation = NULL;
639 memset ((char *) obj + sizeof (MonoObject), 0, size - sizeof (MonoObject));
640 } else if (vtable->gc_descr != GC_NO_DESCRIPTOR) {
641 obj = (MonoObject *)GC_GCJ_MALLOC (size, vtable);
642 if (G_UNLIKELY (!obj))
645 obj = (MonoObject *)GC_MALLOC (size);
646 if (G_UNLIKELY (!obj))
649 obj->vtable = vtable;
652 if (G_UNLIKELY (alloc_events))
653 mono_profiler_allocation (obj);
659 mono_gc_alloc_vector (MonoVTable *vtable, size_t size, uintptr_t max_length)
663 if (!vtable->klass->has_references) {
664 obj = (MonoArray *)GC_MALLOC_ATOMIC (size);
665 if (G_UNLIKELY (!obj))
668 obj->obj.vtable = vtable;
669 obj->obj.synchronisation = NULL;
671 memset ((char *) obj + sizeof (MonoObject), 0, size - sizeof (MonoObject));
672 } else if (vtable->gc_descr != GC_NO_DESCRIPTOR) {
673 obj = (MonoArray *)GC_GCJ_MALLOC (size, vtable);
674 if (G_UNLIKELY (!obj))
677 obj = (MonoArray *)GC_MALLOC (size);
678 if (G_UNLIKELY (!obj))
681 obj->obj.vtable = vtable;
684 obj->max_length = max_length;
686 if (G_UNLIKELY (alloc_events))
687 mono_profiler_allocation (&obj->obj);
693 mono_gc_alloc_array (MonoVTable *vtable, size_t size, uintptr_t max_length, uintptr_t bounds_size)
697 if (!vtable->klass->has_references) {
698 obj = (MonoArray *)GC_MALLOC_ATOMIC (size);
699 if (G_UNLIKELY (!obj))
702 obj->obj.vtable = vtable;
703 obj->obj.synchronisation = NULL;
705 memset ((char *) obj + sizeof (MonoObject), 0, size - sizeof (MonoObject));
706 } else if (vtable->gc_descr != GC_NO_DESCRIPTOR) {
707 obj = (MonoArray *)GC_GCJ_MALLOC (size, vtable);
708 if (G_UNLIKELY (!obj))
711 obj = (MonoArray *)GC_MALLOC (size);
712 if (G_UNLIKELY (!obj))
715 obj->obj.vtable = vtable;
718 obj->max_length = max_length;
721 obj->bounds = (MonoArrayBounds *) ((char *) obj + size - bounds_size);
723 if (G_UNLIKELY (alloc_events))
724 mono_profiler_allocation (&obj->obj);
730 mono_gc_alloc_string (MonoVTable *vtable, size_t size, gint32 len)
732 MonoString *obj = (MonoString *)GC_MALLOC_ATOMIC (size);
733 if (G_UNLIKELY (!obj))
736 obj->object.vtable = vtable;
737 obj->object.synchronisation = NULL;
739 obj->chars [len] = 0;
741 if (G_UNLIKELY (alloc_events))
742 mono_profiler_allocation (&obj->object);
748 mono_gc_alloc_mature (MonoVTable *vtable, size_t size)
750 return mono_gc_alloc_obj (vtable, size);
754 mono_gc_alloc_pinned_obj (MonoVTable *vtable, size_t size)
756 return mono_gc_alloc_obj (vtable, size);
760 mono_gc_invoke_finalizers (void)
762 /* There is a bug in GC_invoke_finalizer () in versions <= 6.2alpha4:
763 * the 'mem_freed' variable is not initialized when there are no
764 * objects to finalize, which leads to strange behavior later on.
765 * The check is necessary to work around that bug.
767 if (GC_should_invoke_finalizers ())
768 return GC_invoke_finalizers ();
773 mono_gc_pending_finalizers (void)
775 return GC_should_invoke_finalizers ();
779 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
781 *(void**)field_ptr = value;
785 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
787 *(void**)slot_ptr = value;
791 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
793 mono_gc_memmove_aligned (dest_ptr, src_ptr, count * sizeof (gpointer));
797 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
799 *(void**)ptr = value;
803 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, MonoObject *value)
805 InterlockedWritePointer ((volatile gpointer *)ptr, value);
809 mono_gc_wbarrier_generic_nostore (gpointer ptr)
814 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
816 mono_gc_memmove_atomic (dest, src, count * mono_class_value_size (klass, NULL));
820 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
822 /* do not copy the sync state */
823 mono_gc_memmove_aligned ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
824 mono_object_class (obj)->instance_size - sizeof (MonoObject));
828 mono_gc_clear_domain (MonoDomain *domain)
833 mono_gc_get_suspend_signal (void)
835 return GC_get_suspend_signal ();
839 mono_gc_get_restart_signal (void)
841 return GC_get_thr_restart_signal ();
844 #if defined(USE_COMPILER_TLS) && defined(__linux__) && (defined(__i386__) || defined(__x86_64__))
845 extern __thread MONO_TLS_FAST void* GC_thread_tls;
846 #include "metadata-internals.h"
852 while (!(v & (1 << i)))
859 ATYPE_FREEPTR_FOR_BOX,
867 create_allocator (int atype, int tls_key, gboolean slowpath)
869 int index_var, bytes_var, my_fl_var, my_entry_var;
870 guint32 no_freelist_branch, not_small_enough_branch = 0;
871 guint32 size_overflow_branch = 0;
872 MonoMethodBuilder *mb;
874 MonoMethodSignature *csig;
875 const char *name = NULL;
878 if (atype == ATYPE_FREEPTR) {
879 name = slowpath ? "SlowAllocPtrfree" : "AllocPtrfree";
880 } else if (atype == ATYPE_FREEPTR_FOR_BOX) {
881 name = slowpath ? "SlowAllocPtrfreeBox" : "AllocPtrfreeBox";
882 } else if (atype == ATYPE_NORMAL) {
883 name = slowpath ? "SlowAlloc" : "Alloc";
884 } else if (atype == ATYPE_GCJ) {
885 name = slowpath ? "SlowAllocGcj" : "AllocGcj";
886 } else if (atype == ATYPE_STRING) {
887 name = slowpath ? "SlowAllocString" : "AllocString";
889 g_assert_not_reached ();
892 csig = mono_metadata_signature_alloc (mono_defaults.corlib, 2);
894 if (atype == ATYPE_STRING) {
895 csig->ret = &mono_defaults.string_class->byval_arg;
896 csig->params [0] = &mono_defaults.int_class->byval_arg;
897 csig->params [1] = &mono_defaults.int32_class->byval_arg;
899 csig->ret = &mono_defaults.object_class->byval_arg;
900 csig->params [0] = &mono_defaults.int_class->byval_arg;
901 csig->params [1] = &mono_defaults.int32_class->byval_arg;
904 mb = mono_mb_new (mono_defaults.object_class, name, MONO_WRAPPER_ALLOC);
907 goto always_slowpath;
909 bytes_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
910 if (atype == ATYPE_STRING) {
911 /* a string alloator method takes the args: (vtable, len) */
912 /* bytes = (offsetof (MonoString, chars) + ((len + 1) * 2)); */
913 mono_mb_emit_ldarg (mb, 1);
914 mono_mb_emit_icon (mb, 1);
915 mono_mb_emit_byte (mb, MONO_CEE_ADD);
916 mono_mb_emit_icon (mb, 1);
917 mono_mb_emit_byte (mb, MONO_CEE_SHL);
918 // sizeof (MonoString) might include padding
919 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, chars));
920 mono_mb_emit_byte (mb, MONO_CEE_ADD);
921 mono_mb_emit_stloc (mb, bytes_var);
923 mono_mb_emit_ldarg (mb, 1);
924 mono_mb_emit_stloc (mb, bytes_var);
927 /* this is needed for strings/arrays only as the other big types are never allocated with this method */
928 if (atype == ATYPE_STRING) {
930 /* if (!SMALL_ENOUGH (bytes)) jump slow_path;*/
931 mono_mb_emit_ldloc (mb, bytes_var);
932 mono_mb_emit_icon (mb, (NFREELISTS-1) * GRANULARITY);
933 not_small_enough_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S);
934 /* check for overflow */
935 mono_mb_emit_ldloc (mb, bytes_var);
936 mono_mb_emit_icon (mb, sizeof (MonoString));
937 size_overflow_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLE_UN_S);
940 /* int index = INDEX_FROM_BYTES(bytes); */
941 index_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
943 mono_mb_emit_ldloc (mb, bytes_var);
944 mono_mb_emit_icon (mb, GRANULARITY - 1);
945 mono_mb_emit_byte (mb, MONO_CEE_ADD);
946 mono_mb_emit_icon (mb, shift_amount (GRANULARITY));
947 mono_mb_emit_byte (mb, MONO_CEE_SHR_UN);
948 mono_mb_emit_icon (mb, shift_amount (sizeof (gpointer)));
949 mono_mb_emit_byte (mb, MONO_CEE_SHL);
950 /* index var is already adjusted into bytes */
951 mono_mb_emit_stloc (mb, index_var);
953 my_fl_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
954 my_entry_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
955 /* my_fl = ((GC_thread)tsd) -> ptrfree_freelists + index; */
956 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
957 mono_mb_emit_byte (mb, 0x0D); /* CEE_MONO_TLS */
958 mono_mb_emit_i4 (mb, tls_key);
959 if (atype == ATYPE_FREEPTR || atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING)
960 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, tlfs)
961 + G_STRUCT_OFFSET (struct thread_local_freelists,
963 else if (atype == ATYPE_NORMAL)
964 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, tlfs)
965 + G_STRUCT_OFFSET (struct thread_local_freelists,
967 else if (atype == ATYPE_GCJ)
968 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, tlfs)
969 + G_STRUCT_OFFSET (struct thread_local_freelists,
972 g_assert_not_reached ();
973 mono_mb_emit_byte (mb, MONO_CEE_ADD);
974 mono_mb_emit_ldloc (mb, index_var);
975 mono_mb_emit_byte (mb, MONO_CEE_ADD);
976 mono_mb_emit_stloc (mb, my_fl_var);
978 /* my_entry = *my_fl; */
979 mono_mb_emit_ldloc (mb, my_fl_var);
980 mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
981 mono_mb_emit_stloc (mb, my_entry_var);
983 /* if (EXPECT((word)my_entry >= HBLKSIZE, 1)) { */
984 mono_mb_emit_ldloc (mb, my_entry_var);
985 mono_mb_emit_icon (mb, HBLKSIZE);
986 no_freelist_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
988 /* ptr_t next = obj_link(my_entry); *my_fl = next; */
989 mono_mb_emit_ldloc (mb, my_fl_var);
990 mono_mb_emit_ldloc (mb, my_entry_var);
991 mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
992 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
994 /* set the vtable and clear the words in the object */
995 mono_mb_emit_ldloc (mb, my_entry_var);
996 mono_mb_emit_ldarg (mb, 0);
997 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
999 if (atype == ATYPE_FREEPTR) {
1000 int start_var, end_var, start_loop;
1001 /* end = my_entry + bytes; start = my_entry + sizeof (gpointer);
1003 start_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
1004 end_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
1005 mono_mb_emit_ldloc (mb, my_entry_var);
1006 mono_mb_emit_ldloc (mb, bytes_var);
1007 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1008 mono_mb_emit_stloc (mb, end_var);
1009 mono_mb_emit_ldloc (mb, my_entry_var);
1010 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
1011 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1012 mono_mb_emit_stloc (mb, start_var);
1016 * } while (start < end);
1018 start_loop = mono_mb_get_label (mb);
1019 mono_mb_emit_ldloc (mb, start_var);
1020 mono_mb_emit_icon (mb, 0);
1021 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
1022 mono_mb_emit_ldloc (mb, start_var);
1023 mono_mb_emit_icon (mb, sizeof (gpointer));
1024 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1025 mono_mb_emit_stloc (mb, start_var);
1027 mono_mb_emit_ldloc (mb, start_var);
1028 mono_mb_emit_ldloc (mb, end_var);
1029 mono_mb_emit_byte (mb, MONO_CEE_BLT_UN_S);
1030 mono_mb_emit_byte (mb, start_loop - (mono_mb_get_label (mb) + 1));
1031 } else if (atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING) {
1032 /* need to clear just the sync pointer */
1033 mono_mb_emit_ldloc (mb, my_entry_var);
1034 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
1035 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1036 mono_mb_emit_icon (mb, 0);
1037 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
1040 if (atype == ATYPE_STRING) {
1041 /* need to set length and clear the last char */
1042 /* s->length = len; */
1043 mono_mb_emit_ldloc (mb, my_entry_var);
1044 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, length));
1045 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1046 mono_mb_emit_ldarg (mb, 1);
1047 mono_mb_emit_byte (mb, MONO_CEE_STIND_I4);
1048 /* s->chars [len] = 0; */
1049 mono_mb_emit_ldloc (mb, my_entry_var);
1050 mono_mb_emit_ldloc (mb, bytes_var);
1051 mono_mb_emit_icon (mb, 2);
1052 mono_mb_emit_byte (mb, MONO_CEE_SUB);
1053 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1054 mono_mb_emit_icon (mb, 0);
1055 mono_mb_emit_byte (mb, MONO_CEE_STIND_I2);
1058 /* return my_entry; */
1059 mono_mb_emit_ldloc (mb, my_entry_var);
1060 mono_mb_emit_byte (mb, MONO_CEE_RET);
1062 mono_mb_patch_short_branch (mb, no_freelist_branch);
1063 if (not_small_enough_branch > 0)
1064 mono_mb_patch_short_branch (mb, not_small_enough_branch);
1065 if (size_overflow_branch > 0)
1066 mono_mb_patch_short_branch (mb, size_overflow_branch);
1068 /* the slow path: we just call back into the runtime */
1070 if (atype == ATYPE_STRING) {
1071 mono_mb_emit_ldarg (mb, 1);
1072 mono_mb_emit_icall (mb, ves_icall_string_alloc);
1074 mono_mb_emit_ldarg (mb, 0);
1075 mono_mb_emit_icall (mb, ves_icall_object_new_specific);
1078 mono_mb_emit_byte (mb, MONO_CEE_RET);
1080 info = mono_wrapper_info_create (mb, WRAPPER_SUBTYPE_NONE);
1081 info->d.alloc.gc_name = "boehm";
1082 info->d.alloc.alloc_type = atype;
1083 mb->init_locals = FALSE;
1085 res = mono_mb_create (mb, csig, 8, info);
1091 static MonoMethod* alloc_method_cache [ATYPE_NUM];
1092 static MonoMethod* slowpath_alloc_method_cache [ATYPE_NUM];
1094 static G_GNUC_UNUSED gboolean
1095 mono_gc_is_critical_method (MonoMethod *method)
1099 for (i = 0; i < ATYPE_NUM; ++i)
1100 if (method == alloc_method_cache [i] || method == slowpath_alloc_method_cache [i])
1107 * If possible, generate a managed method that can quickly allocate objects in class
1108 * @klass. The method will typically have an thread-local inline allocation sequence.
1109 * The signature of the called method is:
1110 * object allocate (MonoVTable *vtable)
1111 * Some of the logic here is similar to mono_class_get_allocation_ftn () i object.c,
1113 * The thread local alloc logic is taken from libgc/pthread_support.c.
1117 mono_gc_get_managed_allocator (MonoClass *klass, gboolean for_box, gboolean known_instance_size)
1121 MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
1123 /*g_print ("thread tls: %d\n", offset);*/
1126 if (!SMALL_ENOUGH (klass->instance_size))
1128 if (mono_class_has_finalizer (klass) || mono_class_is_marshalbyref (klass) || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS))
1132 if (mono_class_is_open_constructed_type (&klass->byval_arg))
1134 if (klass->byval_arg.type == MONO_TYPE_STRING) {
1135 atype = ATYPE_STRING;
1136 } else if (!known_instance_size) {
1138 } else if (!klass->has_references) {
1140 atype = ATYPE_FREEPTR_FOR_BOX;
1142 atype = ATYPE_FREEPTR;
1146 * disabled because we currently do a runtime choice anyway, to
1147 * deal with multiple appdomains.
1148 if (vtable->gc_descr != GC_NO_DESCRIPTOR)
1151 atype = ATYPE_NORMAL;
1154 return mono_gc_get_managed_allocator_by_type (atype, FALSE);
1158 mono_gc_get_managed_array_allocator (MonoClass *klass)
1164 * mono_gc_get_managed_allocator_by_type:
1166 * Return a managed allocator method corresponding to allocator type ATYPE.
1169 mono_gc_get_managed_allocator_by_type (int atype, gboolean slowpath)
1173 MonoMethod **cache = slowpath ? slowpath_alloc_method_cache : alloc_method_cache;
1174 MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
1176 mono_tls_key_set_offset (TLS_KEY_BOEHM_GC_THREAD, offset);
1178 res = cache [atype];
1182 res = create_allocator (atype, TLS_KEY_BOEHM_GC_THREAD, slowpath);
1183 mono_os_mutex_lock (&mono_gc_lock);
1184 if (cache [atype]) {
1185 mono_free_method (res);
1186 res = cache [atype];
1188 mono_memory_barrier ();
1189 cache [atype] = res;
1191 mono_os_mutex_unlock (&mono_gc_lock);
1196 mono_gc_get_managed_allocator_types (void)
1202 mono_gc_get_write_barrier (void)
1204 g_assert_not_reached ();
1210 static G_GNUC_UNUSED gboolean
1211 mono_gc_is_critical_method (MonoMethod *method)
1217 mono_gc_get_managed_allocator (MonoClass *klass, gboolean for_box, gboolean known_instance_size)
1223 mono_gc_get_managed_array_allocator (MonoClass *klass)
1229 mono_gc_get_managed_allocator_by_type (int atype, gboolean slowpath)
1235 mono_gc_get_managed_allocator_types (void)
1241 mono_gc_get_write_barrier (void)
1243 g_assert_not_reached ();
1250 mono_gc_get_specific_write_barrier (gboolean is_concurrent)
1252 g_assert_not_reached ();
1257 mono_gc_get_aligned_size_for_allocator (int size)
1263 mono_gc_get_gc_name (void)
1269 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
1271 return GC_call_with_alloc_lock (func, data);
1275 mono_gc_get_description (void)
1277 return g_strdup (DEFAULT_GC_NAME);
1281 mono_gc_set_desktop_mode (void)
1287 mono_gc_is_moving (void)
1293 mono_gc_is_disabled (void)
1295 if (GC_dont_gc || g_getenv ("GC_DONT_GC"))
1302 mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
1304 g_assert_not_reached ();
1309 mono_gc_get_card_table (int *shift_bits, gpointer *card_mask)
1311 g_assert_not_reached ();
1316 mono_gc_card_table_nursery_check (void)
1318 g_assert_not_reached ();
1323 mono_gc_get_nursery (int *shift_bits, size_t *size)
1329 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1334 mono_gc_precise_stack_mark_enabled (void)
1340 mono_gc_get_logfile (void)
1346 mono_gc_conservatively_scan_area (void *start, void *end)
1348 g_assert_not_reached ();
1352 mono_gc_scan_object (void *obj, void *gc_data)
1354 g_assert_not_reached ();
1359 mono_gc_get_bitmap_for_descr (void *descr, int *numbits)
1361 g_assert_not_reached ();
1366 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
1371 mono_gc_set_stack_end (void *stack_end)
1375 void mono_gc_set_skip_thread (gboolean value)
1380 mono_gc_register_for_finalization (MonoObject *obj, void *user_data)
1385 /* This assertion is not valid when GC_DEBUG is defined */
1386 g_assert (GC_base (obj) == (char*)obj - offset);
1389 GC_REGISTER_FINALIZER_NO_ORDER ((char*)obj - offset, (GC_finalization_proc)user_data, GUINT_TO_POINTER (offset), NULL, NULL);
1394 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
1396 /* it is being replaced by GC_pthread_create on some
1397 * platforms, see libgc/include/gc_pthread_redirects.h */
1398 return pthread_create (new_thread, attr, start_routine, arg);
1403 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
1405 return GC_DllMain (module_handle, reason, reserved);
1410 mono_gc_get_vtable_bits (MonoClass *klass)
1412 if (fin_callbacks.is_class_finalization_aware) {
1413 if (fin_callbacks.is_class_finalization_aware (klass))
1414 return BOEHM_GC_BIT_FINALIZER_AWARE;
1420 * mono_gc_register_altstack:
1422 * Register the dimensions of the normal stack and altstack with the collector.
1423 * Currently, STACK/STACK_SIZE is only used when the thread is suspended while it is on an altstack.
1426 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
1428 GC_register_altstack (stack, stack_size, altstack, altstack_size);
1432 mono_gc_get_los_limit (void)
1438 mono_gc_set_string_length (MonoString *str, gint32 new_length)
1440 mono_unichar2 *new_end = str->chars + new_length;
1442 /* zero the discarded string. This null-delimits the string and allows
1443 * the space to be reclaimed by SGen. */
1445 memset (new_end, 0, (str->length - new_length + 1) * sizeof (mono_unichar2));
1446 str->length = new_length;
1450 mono_gc_user_markers_supported (void)
1456 mono_gc_make_root_descr_user (MonoGCRootMarkFunc marker)
1458 g_assert_not_reached ();
1462 /* Toggleref support */
1465 mono_gc_toggleref_add (MonoObject *object, mono_bool strong_ref)
1467 if (GC_toggleref_add ((GC_PTR)object, (int)strong_ref) != GC_SUCCESS)
1468 g_error ("GC_toggleref_add failed\n");
1472 mono_gc_toggleref_register_callback (MonoToggleRefStatus (*proccess_toggleref) (MonoObject *obj))
1474 GC_set_toggleref_func ((GC_ToggleRefStatus (*) (GC_PTR obj)) proccess_toggleref);
1477 /* Test support code */
1479 static MonoToggleRefStatus
1480 test_toggleref_callback (MonoObject *obj)
1482 static MonoClassField *mono_toggleref_test_field;
1483 MonoToggleRefStatus status = MONO_TOGGLE_REF_DROP;
1485 if (!mono_toggleref_test_field) {
1486 mono_toggleref_test_field = mono_class_get_field_from_name (mono_object_get_class (obj), "__test");
1487 g_assert (mono_toggleref_test_field);
1490 mono_field_get_value (obj, mono_toggleref_test_field, &status);
1491 printf ("toggleref-cb obj %d\n", status);
1496 register_test_toggleref_callback (void)
1498 mono_gc_toggleref_register_callback (test_toggleref_callback);
1502 is_finalization_aware (MonoObject *obj)
1504 MonoVTable *vt = obj->vtable;
1505 return (vt->gc_bits & BOEHM_GC_BIT_FINALIZER_AWARE) == BOEHM_GC_BIT_FINALIZER_AWARE;
1509 fin_notifier (MonoObject *obj)
1511 if (is_finalization_aware (obj))
1512 fin_callbacks.object_queued_for_finalization (obj);
1516 mono_gc_register_finalizer_callbacks (MonoGCFinalizerCallbacks *callbacks)
1518 if (callbacks->version != MONO_GC_FINALIZER_EXTENSION_VERSION)
1519 g_error ("Invalid finalizer callback version. Expected %d but got %d\n", MONO_GC_FINALIZER_EXTENSION_VERSION, callbacks->version);
1521 fin_callbacks = *callbacks;
1523 GC_set_await_finalize_proc ((void (*) (GC_PTR))fin_notifier);
1526 #define BITMAP_SIZE (sizeof (*((HandleData *)NULL)->bitmap) * CHAR_BIT)
1528 static inline gboolean
1529 slot_occupied (HandleData *handles, guint slot) {
1530 return handles->bitmap [slot / BITMAP_SIZE] & (1 << (slot % BITMAP_SIZE));
1534 vacate_slot (HandleData *handles, guint slot) {
1535 handles->bitmap [slot / BITMAP_SIZE] &= ~(1 << (slot % BITMAP_SIZE));
1539 occupy_slot (HandleData *handles, guint slot) {
1540 handles->bitmap [slot / BITMAP_SIZE] |= 1 << (slot % BITMAP_SIZE);
1544 find_first_unset (guint32 bitmap)
1547 for (i = 0; i < 32; ++i) {
1548 if (!(bitmap & (1 << i)))
1555 handle_data_alloc_entries (HandleData *handles)
1558 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1559 handles->entries = (void **)g_malloc0 (sizeof (*handles->entries) * handles->size);
1560 handles->domain_ids = (guint16 *)g_malloc0 (sizeof (*handles->domain_ids) * handles->size);
1562 handles->entries = (void **)mono_gc_alloc_fixed (sizeof (*handles->entries) * handles->size, NULL, MONO_ROOT_SOURCE_GC_HANDLE, "gc handles table");
1564 handles->bitmap = (guint32 *)g_malloc0 (handles->size / CHAR_BIT);
1568 handle_data_next_unset (HandleData *handles)
1571 for (slot = handles->slot_hint; slot < handles->size / BITMAP_SIZE; ++slot) {
1572 if (handles->bitmap [slot] == 0xffffffff)
1574 handles->slot_hint = slot;
1575 return find_first_unset (handles->bitmap [slot]);
1581 handle_data_first_unset (HandleData *handles)
1584 for (slot = 0; slot < handles->slot_hint; ++slot) {
1585 if (handles->bitmap [slot] == 0xffffffff)
1587 handles->slot_hint = slot;
1588 return find_first_unset (handles->bitmap [slot]);
1593 /* Returns the index of the current slot in the bitmap. */
1595 handle_data_grow (HandleData *handles, gboolean track)
1597 guint32 *new_bitmap;
1598 guint32 new_size = handles->size * 2; /* always double: we memset to 0 based on this below */
1600 /* resize and copy the bitmap */
1601 new_bitmap = (guint32 *)g_malloc0 (new_size / CHAR_BIT);
1602 memcpy (new_bitmap, handles->bitmap, handles->size / CHAR_BIT);
1603 g_free (handles->bitmap);
1604 handles->bitmap = new_bitmap;
1606 /* resize and copy the entries */
1607 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1609 guint16 *domain_ids;
1611 domain_ids = (guint16 *)g_malloc0 (sizeof (*handles->domain_ids) * new_size);
1612 entries = (void **)g_malloc0 (sizeof (*handles->entries) * new_size);
1613 memcpy (domain_ids, handles->domain_ids, sizeof (*handles->domain_ids) * handles->size);
1614 for (i = 0; i < handles->size; ++i) {
1615 MonoObject *obj = mono_gc_weak_link_get (&(handles->entries [i]));
1617 mono_gc_weak_link_add (&(entries [i]), obj, track);
1618 mono_gc_weak_link_remove (&(handles->entries [i]), track);
1620 g_assert (!handles->entries [i]);
1623 g_free (handles->entries);
1624 g_free (handles->domain_ids);
1625 handles->entries = entries;
1626 handles->domain_ids = domain_ids;
1629 entries = (void **)mono_gc_alloc_fixed (sizeof (*handles->entries) * new_size, NULL, MONO_ROOT_SOURCE_GC_HANDLE, "gc handles table");
1630 mono_gc_memmove_aligned (entries, handles->entries, sizeof (*handles->entries) * handles->size);
1631 mono_gc_free_fixed (handles->entries);
1632 handles->entries = entries;
1634 handles->slot_hint = handles->size / BITMAP_SIZE;
1635 handles->size = new_size;
1639 alloc_handle (HandleData *handles, MonoObject *obj, gboolean track)
1643 lock_handles (handles);
1645 handle_data_alloc_entries (handles);
1646 i = handle_data_next_unset (handles);
1647 if (i == -1 && handles->slot_hint != 0)
1648 i = handle_data_first_unset (handles);
1650 handle_data_grow (handles, track);
1653 slot = handles->slot_hint * BITMAP_SIZE + i;
1654 occupy_slot (handles, slot);
1655 handles->entries [slot] = NULL;
1656 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1657 /*FIXME, what to use when obj == null?*/
1658 handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
1660 mono_gc_weak_link_add (&(handles->entries [slot]), obj, track);
1662 handles->entries [slot] = obj;
1665 #ifndef DISABLE_PERFCOUNTERS
1666 mono_perfcounters->gc_num_handles++;
1668 unlock_handles (handles);
1669 res = MONO_GC_HANDLE (slot, handles->type);
1670 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_CREATED, handles->type, res, obj);
1675 * mono_gchandle_new:
1676 * @obj: managed object to get a handle for
1677 * @pinned: whether the object should be pinned
1679 * This returns a handle that wraps the object, this is used to keep a
1680 * reference to a managed object from the unmanaged world and preventing the
1681 * object from being disposed.
1683 * If @pinned is false the address of the object can not be obtained, if it is
1684 * true the address of the object can be obtained. This will also pin the
1685 * object so it will not be possible by a moving garbage collector to move the
1688 * Returns: a handle that can be used to access the object from
1692 mono_gchandle_new (MonoObject *obj, gboolean pinned)
1694 return alloc_handle (&gc_handles [pinned? HANDLE_PINNED: HANDLE_NORMAL], obj, FALSE);
1698 * mono_gchandle_new_weakref:
1699 * @obj: managed object to get a handle for
1700 * @track_resurrection: Determines how long to track the object, if this is set to TRUE, the object is tracked after finalization, if FALSE, the object is only tracked up until the point of finalization.
1702 * This returns a weak handle that wraps the object, this is used to
1703 * keep a reference to a managed object from the unmanaged world.
1704 * Unlike the mono_gchandle_new the object can be reclaimed by the
1705 * garbage collector. In this case the value of the GCHandle will be
1708 * If @track_resurrection is TRUE the object will be tracked through
1709 * finalization and if the object is resurrected during the execution
1710 * of the finalizer, then the returned weakref will continue to hold
1711 * a reference to the object. If @track_resurrection is FALSE, then
1712 * the weak reference's target will become NULL as soon as the object
1713 * is passed on to the finalizer.
1715 * Returns: a handle that can be used to access the object from
1719 mono_gchandle_new_weakref (MonoObject *obj, gboolean track_resurrection)
1721 return alloc_handle (&gc_handles [track_resurrection? HANDLE_WEAK_TRACK: HANDLE_WEAK], obj, track_resurrection);
1725 * mono_gchandle_get_target:
1726 * @gchandle: a GCHandle's handle.
1728 * The handle was previously created by calling `mono_gchandle_new` or
1729 * `mono_gchandle_new_weakref`.
1731 * Returns: A pointer to the `MonoObject*` represented by the handle or
1732 * NULL for a collected object if using a weakref handle.
1735 mono_gchandle_get_target (guint32 gchandle)
1737 guint slot = MONO_GC_HANDLE_SLOT (gchandle);
1738 guint type = MONO_GC_HANDLE_TYPE (gchandle);
1739 HandleData *handles = &gc_handles [type];
1740 MonoObject *obj = NULL;
1741 if (type >= HANDLE_TYPE_MAX)
1744 lock_handles (handles);
1745 if (slot < handles->size && slot_occupied (handles, slot)) {
1746 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1747 obj = mono_gc_weak_link_get (&handles->entries [slot]);
1749 obj = (MonoObject *)handles->entries [slot];
1752 /* print a warning? */
1754 unlock_handles (handles);
1755 /*g_print ("get target of entry %d of type %d: %p\n", slot, handles->type, obj);*/
1760 mono_gchandle_set_target (guint32 gchandle, MonoObject *obj)
1762 guint slot = MONO_GC_HANDLE_SLOT (gchandle);
1763 guint type = MONO_GC_HANDLE_TYPE (gchandle);
1764 HandleData *handles = &gc_handles [type];
1765 MonoObject *old_obj = NULL;
1767 g_assert (type < HANDLE_TYPE_MAX);
1768 lock_handles (handles);
1769 if (slot < handles->size && slot_occupied (handles, slot)) {
1770 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1771 old_obj = (MonoObject *)handles->entries [slot];
1772 if (handles->entries [slot])
1773 mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
1775 mono_gc_weak_link_add (&handles->entries [slot], obj, handles->type == HANDLE_WEAK_TRACK);
1776 /*FIXME, what to use when obj == null?*/
1777 handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
1779 handles->entries [slot] = obj;
1782 /* print a warning? */
1784 /*g_print ("changed entry %d of type %d to object %p (in slot: %p)\n", slot, handles->type, obj, handles->entries [slot]);*/
1785 unlock_handles (handles);
1789 mono_gc_is_null (void)
1795 * mono_gchandle_is_in_domain:
1796 * @gchandle: a GCHandle's handle.
1797 * @domain: An application domain.
1799 * Use this function to determine if the @gchandle points to an
1800 * object allocated in the specified @domain.
1802 * Returns: TRUE if the object wrapped by the @gchandle belongs to the specific @domain.
1805 mono_gchandle_is_in_domain (guint32 gchandle, MonoDomain *domain)
1807 guint slot = MONO_GC_HANDLE_SLOT (gchandle);
1808 guint type = MONO_GC_HANDLE_TYPE (gchandle);
1809 HandleData *handles = &gc_handles [type];
1810 gboolean result = FALSE;
1812 if (type >= HANDLE_TYPE_MAX)
1815 lock_handles (handles);
1816 if (slot < handles->size && slot_occupied (handles, slot)) {
1817 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1818 result = domain->domain_id == handles->domain_ids [slot];
1821 obj = (MonoObject *)handles->entries [slot];
1825 result = domain == mono_object_domain (obj);
1828 /* print a warning? */
1830 unlock_handles (handles);
1835 * mono_gchandle_free:
1836 * @gchandle: a GCHandle's handle.
1838 * Frees the @gchandle handle. If there are no outstanding
1839 * references, the garbage collector can reclaim the memory of the
1843 mono_gchandle_free (guint32 gchandle)
1845 guint slot = MONO_GC_HANDLE_SLOT (gchandle);
1846 guint type = MONO_GC_HANDLE_TYPE (gchandle);
1847 HandleData *handles = &gc_handles [type];
1848 if (type >= HANDLE_TYPE_MAX)
1851 lock_handles (handles);
1852 if (slot < handles->size && slot_occupied (handles, slot)) {
1853 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1854 if (handles->entries [slot])
1855 mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
1857 handles->entries [slot] = NULL;
1859 vacate_slot (handles, slot);
1861 /* print a warning? */
1863 #ifndef DISABLE_PERFCOUNTERS
1864 mono_perfcounters->gc_num_handles--;
1866 /*g_print ("freed entry %d of type %d\n", slot, handles->type);*/
1867 unlock_handles (handles);
1868 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_DESTROYED, handles->type, gchandle, NULL);
1872 * mono_gchandle_free_domain:
1873 * @domain: domain that is unloading
1875 * Function used internally to cleanup any GC handle for objects belonging
1876 * to the specified domain during appdomain unload.
1879 mono_gchandle_free_domain (MonoDomain *domain)
1883 for (type = HANDLE_TYPE_MIN; type < HANDLE_PINNED; ++type) {
1885 HandleData *handles = &gc_handles [type];
1886 lock_handles (handles);
1887 for (slot = 0; slot < handles->size; ++slot) {
1888 if (!slot_occupied (handles, slot))
1890 if (MONO_GC_HANDLE_TYPE_IS_WEAK (type)) {
1891 if (domain->domain_id == handles->domain_ids [slot]) {
1892 vacate_slot (handles, slot);
1893 if (handles->entries [slot])
1894 mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
1897 if (handles->entries [slot] && mono_object_domain (handles->entries [slot]) == domain) {
1898 vacate_slot (handles, slot);
1899 handles->entries [slot] = NULL;
1903 unlock_handles (handles);
1908 #endif /* no Boehm GC */