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)
13 #define GC_I_HIDE_POINTERS
14 #include <mono/metadata/gc-internals.h>
15 #include <mono/metadata/mono-gc.h>
16 #include <mono/metadata/profiler-private.h>
17 #include <mono/metadata/class-internals.h>
18 #include <mono/metadata/method-builder.h>
19 #include <mono/metadata/opcodes.h>
20 #include <mono/metadata/domain-internals.h>
21 #include <mono/metadata/metadata-internals.h>
22 #include <mono/metadata/marshal.h>
23 #include <mono/metadata/runtime.h>
24 #include <mono/metadata/sgen-toggleref.h>
25 #include <mono/utils/atomic.h>
26 #include <mono/utils/mono-logger-internals.h>
27 #include <mono/utils/mono-memory-model.h>
28 #include <mono/utils/mono-time.h>
29 #include <mono/utils/mono-threads.h>
30 #include <mono/utils/dtrace.h>
31 #include <mono/utils/gc_wrapper.h>
32 #include <mono/utils/mono-os-mutex.h>
33 #include <mono/utils/mono-counters.h>
39 #define THREAD_LOCAL_ALLOC 1
40 #include "private/pthread_support.h"
42 #if defined(PLATFORM_MACOSX) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
43 void *pthread_get_stackaddr_np(pthread_t);
46 #define GC_NO_DESCRIPTOR ((gpointer)(0 | GC_DS_LENGTH))
47 /*Boehm max heap cannot be smaller than 16MB*/
48 #define MIN_BOEHM_MAX_HEAP_SIZE_IN_MB 16
49 #define MIN_BOEHM_MAX_HEAP_SIZE (MIN_BOEHM_MAX_HEAP_SIZE_IN_MB << 20)
51 static gboolean gc_initialized = FALSE;
52 static mono_mutex_t mono_gc_lock;
55 boehm_thread_register (MonoThreadInfo* info, void *baseptr);
57 boehm_thread_unregister (MonoThreadInfo *p);
59 register_test_toggleref_callback (void);
61 #define BOEHM_GC_BIT_FINALIZER_AWARE 1
62 static MonoGCFinalizerCallbacks fin_callbacks;
66 static mono_mutex_t handle_section;
67 #define lock_handles(handles) mono_os_mutex_lock (&handle_section)
68 #define unlock_handles(handles) mono_os_mutex_unlock (&handle_section)
75 guint slot_hint : 24; /* starting slot for search in bitmap */
76 /* 2^16 appdomains should be enough for everyone (though I know I'll regret this in 20 years) */
77 /* we alloc this only for weak refs, since we can get the domain directly in the other cases */
81 #define EMPTY_HANDLE_DATA(type) {NULL, NULL, 0, (type), 0, NULL}
83 /* weak and weak-track arrays will be allocated in malloc memory
85 static HandleData gc_handles [] = {
86 EMPTY_HANDLE_DATA (HANDLE_WEAK),
87 EMPTY_HANDLE_DATA (HANDLE_WEAK_TRACK),
88 EMPTY_HANDLE_DATA (HANDLE_NORMAL),
89 EMPTY_HANDLE_DATA (HANDLE_PINNED)
93 mono_gc_warning (char *msg, GC_word arg)
95 mono_trace (G_LOG_LEVEL_WARNING, MONO_TRACE_GC, msg, (unsigned long)arg);
99 mono_gc_base_init (void)
101 MonoThreadInfoCallbacks cb;
108 mono_counters_init ();
111 * Handle the case when we are called from a thread different from the main thread,
113 * FIXME: Move this to libgc where it belongs.
115 * we used to do this only when running on valgrind,
116 * but it happens also in other setups.
118 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK) && !defined(__native_client__)
123 pthread_getattr_np (pthread_self (), &attr);
124 pthread_attr_getstack (&attr, &sstart, &size);
125 pthread_attr_destroy (&attr);
126 /*g_print ("stackbottom pth is: %p\n", (char*)sstart + size);*/
129 * The calculation above doesn't seem to work on ia64, also we need to set
130 * GC_register_stackbottom as well, but don't know how.
133 /* apparently with some linuxthreads implementations sstart can be NULL,
134 * fallback to the more imprecise method (bug# 78096).
137 GC_stackbottom = (char*)sstart + size;
140 gsize stack_bottom = (gsize)&dummy;
141 stack_bottom += 4095;
142 stack_bottom &= ~4095;
143 GC_stackbottom = (char*)stack_bottom;
147 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
148 GC_stackbottom = (char*)pthread_get_stackaddr_np (pthread_self ());
149 #elif defined(__OpenBSD__)
150 # include <pthread_np.h>
155 rslt = pthread_stackseg_np(pthread_self(), &ss);
156 g_assert (rslt == 0);
158 GC_stackbottom = (char*)ss.ss_sp;
160 #elif defined(__native_client__)
161 /* Do nothing, GC_stackbottom is set correctly in libgc */
165 gsize stack_bottom = (gsize)&dummy;
166 stack_bottom += 4095;
167 stack_bottom &= ~4095;
168 /*g_print ("stackbottom is: %p\n", (char*)stack_bottom);*/
169 GC_stackbottom = (char*)stack_bottom;
173 #if !defined(PLATFORM_ANDROID)
174 /* If GC_no_dls is set to true, GC_find_limit is not called. This causes a seg fault on Android. */
178 if ((env = g_getenv ("MONO_GC_DEBUG"))) {
179 char **opts = g_strsplit (env, ",", -1);
180 for (char **ptr = opts; ptr && *ptr; ptr ++) {
182 if (!strcmp (opt, "do-not-finalize")) {
183 mono_do_not_finalize = 1;
184 } else if (!strcmp (opt, "log-finalizers")) {
193 GC_oom_fn = mono_gc_out_of_memory;
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);
634 obj->vtable = vtable;
635 obj->synchronisation = NULL;
637 memset ((char *) obj + sizeof (MonoObject), 0, size - sizeof (MonoObject));
638 } else if (vtable->gc_descr != GC_NO_DESCRIPTOR) {
639 obj = (MonoObject *)GC_GCJ_MALLOC (size, vtable);
641 obj = (MonoObject *)GC_MALLOC (size);
643 obj->vtable = vtable;
646 if (G_UNLIKELY (alloc_events))
647 mono_profiler_allocation (obj);
653 mono_gc_alloc_vector (MonoVTable *vtable, size_t size, uintptr_t max_length)
657 if (!vtable->klass->has_references) {
658 obj = (MonoArray *)GC_MALLOC_ATOMIC (size);
660 obj->obj.vtable = vtable;
661 obj->obj.synchronisation = NULL;
663 memset ((char *) obj + sizeof (MonoObject), 0, size - sizeof (MonoObject));
664 } else if (vtable->gc_descr != GC_NO_DESCRIPTOR) {
665 obj = (MonoArray *)GC_GCJ_MALLOC (size, vtable);
667 obj = (MonoArray *)GC_MALLOC (size);
669 obj->obj.vtable = vtable;
672 obj->max_length = max_length;
674 if (G_UNLIKELY (alloc_events))
675 mono_profiler_allocation (&obj->obj);
681 mono_gc_alloc_array (MonoVTable *vtable, size_t size, uintptr_t max_length, uintptr_t bounds_size)
685 if (!vtable->klass->has_references) {
686 obj = (MonoArray *)GC_MALLOC_ATOMIC (size);
688 obj->obj.vtable = vtable;
689 obj->obj.synchronisation = NULL;
691 memset ((char *) obj + sizeof (MonoObject), 0, size - sizeof (MonoObject));
692 } else if (vtable->gc_descr != GC_NO_DESCRIPTOR) {
693 obj = (MonoArray *)GC_GCJ_MALLOC (size, vtable);
695 obj = (MonoArray *)GC_MALLOC (size);
697 obj->obj.vtable = vtable;
700 obj->max_length = max_length;
703 obj->bounds = (MonoArrayBounds *) ((char *) obj + size - bounds_size);
705 if (G_UNLIKELY (alloc_events))
706 mono_profiler_allocation (&obj->obj);
712 mono_gc_alloc_string (MonoVTable *vtable, size_t size, gint32 len)
714 MonoString *obj = (MonoString *)GC_MALLOC_ATOMIC (size);
716 obj->object.vtable = vtable;
717 obj->object.synchronisation = NULL;
719 obj->chars [len] = 0;
721 if (G_UNLIKELY (alloc_events))
722 mono_profiler_allocation (&obj->object);
728 mono_gc_invoke_finalizers (void)
730 /* There is a bug in GC_invoke_finalizer () in versions <= 6.2alpha4:
731 * the 'mem_freed' variable is not initialized when there are no
732 * objects to finalize, which leads to strange behavior later on.
733 * The check is necessary to work around that bug.
735 if (GC_should_invoke_finalizers ())
736 return GC_invoke_finalizers ();
741 mono_gc_pending_finalizers (void)
743 return GC_should_invoke_finalizers ();
747 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
749 *(void**)field_ptr = value;
753 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
755 *(void**)slot_ptr = value;
759 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
761 mono_gc_memmove_aligned (dest_ptr, src_ptr, count * sizeof (gpointer));
765 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
767 *(void**)ptr = value;
771 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, MonoObject *value)
773 InterlockedWritePointer ((volatile gpointer *)ptr, value);
777 mono_gc_wbarrier_generic_nostore (gpointer ptr)
782 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
784 mono_gc_memmove_atomic (dest, src, count * mono_class_value_size (klass, NULL));
788 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
790 /* do not copy the sync state */
791 mono_gc_memmove_aligned ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
792 mono_object_class (obj)->instance_size - sizeof (MonoObject));
796 mono_gc_clear_domain (MonoDomain *domain)
801 mono_gc_get_suspend_signal (void)
803 return GC_get_suspend_signal ();
807 mono_gc_get_restart_signal (void)
809 return GC_get_thr_restart_signal ();
812 #if defined(USE_COMPILER_TLS) && defined(__linux__) && (defined(__i386__) || defined(__x86_64__))
813 extern __thread MONO_TLS_FAST void* GC_thread_tls;
814 #include "metadata-internals.h"
820 while (!(v & (1 << i)))
827 ATYPE_FREEPTR_FOR_BOX,
835 create_allocator (int atype, int tls_key, gboolean slowpath)
837 int index_var, bytes_var, my_fl_var, my_entry_var;
838 guint32 no_freelist_branch, not_small_enough_branch = 0;
839 guint32 size_overflow_branch = 0;
840 MonoMethodBuilder *mb;
842 MonoMethodSignature *csig;
843 const char *name = NULL;
846 if (atype == ATYPE_FREEPTR) {
847 name = slowpath ? "SlowAllocPtrfree" : "AllocPtrfree";
848 } else if (atype == ATYPE_FREEPTR_FOR_BOX) {
849 name = slowpath ? "SlowAllocPtrfreeBox" : "AllocPtrfreeBox";
850 } else if (atype == ATYPE_NORMAL) {
851 name = slowpath ? "SlowAlloc" : "Alloc";
852 } else if (atype == ATYPE_GCJ) {
853 name = slowpath ? "SlowAllocGcj" : "AllocGcj";
854 } else if (atype == ATYPE_STRING) {
855 name = slowpath ? "SlowAllocString" : "AllocString";
857 g_assert_not_reached ();
860 csig = mono_metadata_signature_alloc (mono_defaults.corlib, 2);
862 if (atype == ATYPE_STRING) {
863 csig->ret = &mono_defaults.string_class->byval_arg;
864 csig->params [0] = &mono_defaults.int_class->byval_arg;
865 csig->params [1] = &mono_defaults.int32_class->byval_arg;
867 csig->ret = &mono_defaults.object_class->byval_arg;
868 csig->params [0] = &mono_defaults.int_class->byval_arg;
869 csig->params [1] = &mono_defaults.int32_class->byval_arg;
872 mb = mono_mb_new (mono_defaults.object_class, name, MONO_WRAPPER_ALLOC);
875 goto always_slowpath;
877 bytes_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
878 if (atype == ATYPE_STRING) {
879 /* a string alloator method takes the args: (vtable, len) */
880 /* bytes = (offsetof (MonoString, chars) + ((len + 1) * 2)); */
881 mono_mb_emit_ldarg (mb, 1);
882 mono_mb_emit_icon (mb, 1);
883 mono_mb_emit_byte (mb, MONO_CEE_ADD);
884 mono_mb_emit_icon (mb, 1);
885 mono_mb_emit_byte (mb, MONO_CEE_SHL);
886 // sizeof (MonoString) might include padding
887 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, chars));
888 mono_mb_emit_byte (mb, MONO_CEE_ADD);
889 mono_mb_emit_stloc (mb, bytes_var);
891 mono_mb_emit_ldarg (mb, 1);
892 mono_mb_emit_stloc (mb, bytes_var);
895 /* this is needed for strings/arrays only as the other big types are never allocated with this method */
896 if (atype == ATYPE_STRING) {
898 /* if (!SMALL_ENOUGH (bytes)) jump slow_path;*/
899 mono_mb_emit_ldloc (mb, bytes_var);
900 mono_mb_emit_icon (mb, (NFREELISTS-1) * GRANULARITY);
901 not_small_enough_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S);
902 /* check for overflow */
903 mono_mb_emit_ldloc (mb, bytes_var);
904 mono_mb_emit_icon (mb, sizeof (MonoString));
905 size_overflow_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLE_UN_S);
908 /* int index = INDEX_FROM_BYTES(bytes); */
909 index_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
911 mono_mb_emit_ldloc (mb, bytes_var);
912 mono_mb_emit_icon (mb, GRANULARITY - 1);
913 mono_mb_emit_byte (mb, MONO_CEE_ADD);
914 mono_mb_emit_icon (mb, shift_amount (GRANULARITY));
915 mono_mb_emit_byte (mb, MONO_CEE_SHR_UN);
916 mono_mb_emit_icon (mb, shift_amount (sizeof (gpointer)));
917 mono_mb_emit_byte (mb, MONO_CEE_SHL);
918 /* index var is already adjusted into bytes */
919 mono_mb_emit_stloc (mb, index_var);
921 my_fl_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
922 my_entry_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
923 /* my_fl = ((GC_thread)tsd) -> ptrfree_freelists + index; */
924 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
925 mono_mb_emit_byte (mb, 0x0D); /* CEE_MONO_TLS */
926 mono_mb_emit_i4 (mb, tls_key);
927 if (atype == ATYPE_FREEPTR || atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING)
928 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, tlfs)
929 + G_STRUCT_OFFSET (struct thread_local_freelists,
931 else if (atype == ATYPE_NORMAL)
932 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, tlfs)
933 + G_STRUCT_OFFSET (struct thread_local_freelists,
935 else if (atype == ATYPE_GCJ)
936 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, tlfs)
937 + G_STRUCT_OFFSET (struct thread_local_freelists,
940 g_assert_not_reached ();
941 mono_mb_emit_byte (mb, MONO_CEE_ADD);
942 mono_mb_emit_ldloc (mb, index_var);
943 mono_mb_emit_byte (mb, MONO_CEE_ADD);
944 mono_mb_emit_stloc (mb, my_fl_var);
946 /* my_entry = *my_fl; */
947 mono_mb_emit_ldloc (mb, my_fl_var);
948 mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
949 mono_mb_emit_stloc (mb, my_entry_var);
951 /* if (EXPECT((word)my_entry >= HBLKSIZE, 1)) { */
952 mono_mb_emit_ldloc (mb, my_entry_var);
953 mono_mb_emit_icon (mb, HBLKSIZE);
954 no_freelist_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
956 /* ptr_t next = obj_link(my_entry); *my_fl = next; */
957 mono_mb_emit_ldloc (mb, my_fl_var);
958 mono_mb_emit_ldloc (mb, my_entry_var);
959 mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
960 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
962 /* set the vtable and clear the words in the object */
963 mono_mb_emit_ldloc (mb, my_entry_var);
964 mono_mb_emit_ldarg (mb, 0);
965 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
967 if (atype == ATYPE_FREEPTR) {
968 int start_var, end_var, start_loop;
969 /* end = my_entry + bytes; start = my_entry + sizeof (gpointer);
971 start_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
972 end_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
973 mono_mb_emit_ldloc (mb, my_entry_var);
974 mono_mb_emit_ldloc (mb, bytes_var);
975 mono_mb_emit_byte (mb, MONO_CEE_ADD);
976 mono_mb_emit_stloc (mb, end_var);
977 mono_mb_emit_ldloc (mb, my_entry_var);
978 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
979 mono_mb_emit_byte (mb, MONO_CEE_ADD);
980 mono_mb_emit_stloc (mb, start_var);
984 * } while (start < end);
986 start_loop = mono_mb_get_label (mb);
987 mono_mb_emit_ldloc (mb, start_var);
988 mono_mb_emit_icon (mb, 0);
989 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
990 mono_mb_emit_ldloc (mb, start_var);
991 mono_mb_emit_icon (mb, sizeof (gpointer));
992 mono_mb_emit_byte (mb, MONO_CEE_ADD);
993 mono_mb_emit_stloc (mb, start_var);
995 mono_mb_emit_ldloc (mb, start_var);
996 mono_mb_emit_ldloc (mb, end_var);
997 mono_mb_emit_byte (mb, MONO_CEE_BLT_UN_S);
998 mono_mb_emit_byte (mb, start_loop - (mono_mb_get_label (mb) + 1));
999 } else if (atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING) {
1000 /* need to clear just the sync pointer */
1001 mono_mb_emit_ldloc (mb, my_entry_var);
1002 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
1003 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1004 mono_mb_emit_icon (mb, 0);
1005 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
1008 if (atype == ATYPE_STRING) {
1009 /* need to set length and clear the last char */
1010 /* s->length = len; */
1011 mono_mb_emit_ldloc (mb, my_entry_var);
1012 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, length));
1013 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1014 mono_mb_emit_ldarg (mb, 1);
1015 mono_mb_emit_byte (mb, MONO_CEE_STIND_I4);
1016 /* s->chars [len] = 0; */
1017 mono_mb_emit_ldloc (mb, my_entry_var);
1018 mono_mb_emit_ldloc (mb, bytes_var);
1019 mono_mb_emit_icon (mb, 2);
1020 mono_mb_emit_byte (mb, MONO_CEE_SUB);
1021 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1022 mono_mb_emit_icon (mb, 0);
1023 mono_mb_emit_byte (mb, MONO_CEE_STIND_I2);
1026 /* return my_entry; */
1027 mono_mb_emit_ldloc (mb, my_entry_var);
1028 mono_mb_emit_byte (mb, MONO_CEE_RET);
1030 mono_mb_patch_short_branch (mb, no_freelist_branch);
1031 if (not_small_enough_branch > 0)
1032 mono_mb_patch_short_branch (mb, not_small_enough_branch);
1033 if (size_overflow_branch > 0)
1034 mono_mb_patch_short_branch (mb, size_overflow_branch);
1036 /* the slow path: we just call back into the runtime */
1038 if (atype == ATYPE_STRING) {
1039 mono_mb_emit_ldarg (mb, 1);
1040 mono_mb_emit_icall (mb, mono_string_alloc);
1042 mono_mb_emit_ldarg (mb, 0);
1043 mono_mb_emit_icall (mb, mono_object_new_specific);
1046 mono_mb_emit_byte (mb, MONO_CEE_RET);
1048 info = mono_wrapper_info_create (mb, WRAPPER_SUBTYPE_NONE);
1049 info->d.alloc.gc_name = "boehm";
1050 info->d.alloc.alloc_type = atype;
1052 res = mono_mb_create (mb, csig, 8, info);
1054 mono_method_get_header (res)->init_locals = FALSE;
1059 static MonoMethod* alloc_method_cache [ATYPE_NUM];
1060 static MonoMethod* slowpath_alloc_method_cache [ATYPE_NUM];
1062 static G_GNUC_UNUSED gboolean
1063 mono_gc_is_critical_method (MonoMethod *method)
1067 for (i = 0; i < ATYPE_NUM; ++i)
1068 if (method == alloc_method_cache [i] || method == slowpath_alloc_method_cache [i])
1075 * If possible, generate a managed method that can quickly allocate objects in class
1076 * @klass. The method will typically have an thread-local inline allocation sequence.
1077 * The signature of the called method is:
1078 * object allocate (MonoVTable *vtable)
1079 * Some of the logic here is similar to mono_class_get_allocation_ftn () i object.c,
1081 * The thread local alloc logic is taken from libgc/pthread_support.c.
1085 mono_gc_get_managed_allocator (MonoClass *klass, gboolean for_box, gboolean known_instance_size)
1089 MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
1091 /*g_print ("thread tls: %d\n", offset);*/
1094 if (!SMALL_ENOUGH (klass->instance_size))
1096 if (mono_class_has_finalizer (klass) || mono_class_is_marshalbyref (klass) || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS))
1100 if (mono_class_is_open_constructed_type (&klass->byval_arg))
1102 if (klass->byval_arg.type == MONO_TYPE_STRING) {
1103 atype = ATYPE_STRING;
1104 } else if (!known_instance_size) {
1106 } else if (!klass->has_references) {
1108 atype = ATYPE_FREEPTR_FOR_BOX;
1110 atype = ATYPE_FREEPTR;
1114 * disabled because we currently do a runtime choice anyway, to
1115 * deal with multiple appdomains.
1116 if (vtable->gc_descr != GC_NO_DESCRIPTOR)
1119 atype = ATYPE_NORMAL;
1122 return mono_gc_get_managed_allocator_by_type (atype, FALSE);
1126 mono_gc_get_managed_array_allocator (MonoClass *klass)
1132 * mono_gc_get_managed_allocator_by_type:
1134 * Return a managed allocator method corresponding to allocator type ATYPE.
1137 mono_gc_get_managed_allocator_by_type (int atype, gboolean slowpath)
1141 MonoMethod **cache = slowpath ? slowpath_alloc_method_cache : alloc_method_cache;
1142 MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
1144 mono_tls_key_set_offset (TLS_KEY_BOEHM_GC_THREAD, offset);
1146 res = cache [atype];
1150 res = create_allocator (atype, TLS_KEY_BOEHM_GC_THREAD, slowpath);
1151 mono_os_mutex_lock (&mono_gc_lock);
1152 if (cache [atype]) {
1153 mono_free_method (res);
1154 res = cache [atype];
1156 mono_memory_barrier ();
1157 cache [atype] = res;
1159 mono_os_mutex_unlock (&mono_gc_lock);
1164 mono_gc_get_managed_allocator_types (void)
1170 mono_gc_get_write_barrier (void)
1172 g_assert_not_reached ();
1178 static G_GNUC_UNUSED gboolean
1179 mono_gc_is_critical_method (MonoMethod *method)
1185 mono_gc_get_managed_allocator (MonoClass *klass, gboolean for_box, gboolean known_instance_size)
1191 mono_gc_get_managed_array_allocator (MonoClass *klass)
1197 mono_gc_get_managed_allocator_by_type (int atype, gboolean slowpath)
1203 mono_gc_get_managed_allocator_types (void)
1209 mono_gc_get_write_barrier (void)
1211 g_assert_not_reached ();
1218 mono_gc_get_specific_write_barrier (gboolean is_concurrent)
1220 g_assert_not_reached ();
1225 mono_gc_get_aligned_size_for_allocator (int size)
1231 mono_gc_get_gc_name (void)
1237 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
1239 return GC_call_with_alloc_lock (func, data);
1243 mono_gc_get_description (void)
1245 return g_strdup (DEFAULT_GC_NAME);
1249 mono_gc_set_desktop_mode (void)
1255 mono_gc_is_moving (void)
1261 mono_gc_is_disabled (void)
1263 if (GC_dont_gc || g_getenv ("GC_DONT_GC"))
1270 mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
1272 g_assert_not_reached ();
1277 mono_gc_get_card_table (int *shift_bits, gpointer *card_mask)
1279 g_assert_not_reached ();
1284 mono_gc_card_table_nursery_check (void)
1286 g_assert_not_reached ();
1291 mono_gc_get_nursery (int *shift_bits, size_t *size)
1297 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1302 mono_gc_precise_stack_mark_enabled (void)
1308 mono_gc_get_logfile (void)
1314 mono_gc_conservatively_scan_area (void *start, void *end)
1316 g_assert_not_reached ();
1320 mono_gc_scan_object (void *obj, void *gc_data)
1322 g_assert_not_reached ();
1327 mono_gc_get_bitmap_for_descr (void *descr, int *numbits)
1329 g_assert_not_reached ();
1334 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
1339 mono_gc_set_stack_end (void *stack_end)
1343 void mono_gc_set_skip_thread (gboolean value)
1348 mono_gc_register_for_finalization (MonoObject *obj, void *user_data)
1353 /* This assertion is not valid when GC_DEBUG is defined */
1354 g_assert (GC_base (obj) == (char*)obj - offset);
1357 GC_REGISTER_FINALIZER_NO_ORDER ((char*)obj - offset, (GC_finalization_proc)user_data, GUINT_TO_POINTER (offset), NULL, NULL);
1362 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
1364 /* it is being replaced by GC_pthread_create on some
1365 * platforms, see libgc/include/gc_pthread_redirects.h */
1366 return pthread_create (new_thread, attr, start_routine, arg);
1371 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
1373 return GC_DllMain (module_handle, reason, reserved);
1378 mono_gc_get_vtable_bits (MonoClass *klass)
1380 if (fin_callbacks.is_class_finalization_aware) {
1381 if (fin_callbacks.is_class_finalization_aware (klass))
1382 return BOEHM_GC_BIT_FINALIZER_AWARE;
1388 * mono_gc_register_altstack:
1390 * Register the dimensions of the normal stack and altstack with the collector.
1391 * Currently, STACK/STACK_SIZE is only used when the thread is suspended while it is on an altstack.
1394 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
1396 GC_register_altstack (stack, stack_size, altstack, altstack_size);
1400 mono_gc_get_los_limit (void)
1406 mono_gc_set_string_length (MonoString *str, gint32 new_length)
1408 mono_unichar2 *new_end = str->chars + new_length;
1410 /* zero the discarded string. This null-delimits the string and allows
1411 * the space to be reclaimed by SGen. */
1413 memset (new_end, 0, (str->length - new_length + 1) * sizeof (mono_unichar2));
1414 str->length = new_length;
1418 mono_gc_user_markers_supported (void)
1424 mono_gc_make_root_descr_user (MonoGCRootMarkFunc marker)
1426 g_assert_not_reached ();
1430 /* Toggleref support */
1433 mono_gc_toggleref_add (MonoObject *object, mono_bool strong_ref)
1435 if (GC_toggleref_add ((GC_PTR)object, (int)strong_ref) != GC_SUCCESS)
1436 g_error ("GC_toggleref_add failed\n");
1440 mono_gc_toggleref_register_callback (MonoToggleRefStatus (*proccess_toggleref) (MonoObject *obj))
1442 GC_set_toggleref_func ((GC_ToggleRefStatus (*) (GC_PTR obj)) proccess_toggleref);
1445 /* Test support code */
1447 static MonoToggleRefStatus
1448 test_toggleref_callback (MonoObject *obj)
1450 static MonoClassField *mono_toggleref_test_field;
1451 MonoToggleRefStatus status = MONO_TOGGLE_REF_DROP;
1453 if (!mono_toggleref_test_field) {
1454 mono_toggleref_test_field = mono_class_get_field_from_name (mono_object_get_class (obj), "__test");
1455 g_assert (mono_toggleref_test_field);
1458 mono_field_get_value (obj, mono_toggleref_test_field, &status);
1459 printf ("toggleref-cb obj %d\n", status);
1464 register_test_toggleref_callback (void)
1466 mono_gc_toggleref_register_callback (test_toggleref_callback);
1470 is_finalization_aware (MonoObject *obj)
1472 MonoVTable *vt = obj->vtable;
1473 return (vt->gc_bits & BOEHM_GC_BIT_FINALIZER_AWARE) == BOEHM_GC_BIT_FINALIZER_AWARE;
1477 fin_notifier (MonoObject *obj)
1479 if (is_finalization_aware (obj))
1480 fin_callbacks.object_queued_for_finalization (obj);
1484 mono_gc_register_finalizer_callbacks (MonoGCFinalizerCallbacks *callbacks)
1486 if (callbacks->version != MONO_GC_FINALIZER_EXTENSION_VERSION)
1487 g_error ("Invalid finalizer callback version. Expected %d but got %d\n", MONO_GC_FINALIZER_EXTENSION_VERSION, callbacks->version);
1489 fin_callbacks = *callbacks;
1491 GC_set_await_finalize_proc ((void (*) (GC_PTR))fin_notifier);
1494 #define BITMAP_SIZE (sizeof (*((HandleData *)NULL)->bitmap) * CHAR_BIT)
1496 static inline gboolean
1497 slot_occupied (HandleData *handles, guint slot) {
1498 return handles->bitmap [slot / BITMAP_SIZE] & (1 << (slot % BITMAP_SIZE));
1502 vacate_slot (HandleData *handles, guint slot) {
1503 handles->bitmap [slot / BITMAP_SIZE] &= ~(1 << (slot % BITMAP_SIZE));
1507 occupy_slot (HandleData *handles, guint slot) {
1508 handles->bitmap [slot / BITMAP_SIZE] |= 1 << (slot % BITMAP_SIZE);
1512 find_first_unset (guint32 bitmap)
1515 for (i = 0; i < 32; ++i) {
1516 if (!(bitmap & (1 << i)))
1523 handle_data_alloc_entries (HandleData *handles)
1526 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1527 handles->entries = (void **)g_malloc0 (sizeof (*handles->entries) * handles->size);
1528 handles->domain_ids = (guint16 *)g_malloc0 (sizeof (*handles->domain_ids) * handles->size);
1530 handles->entries = (void **)mono_gc_alloc_fixed (sizeof (*handles->entries) * handles->size, NULL, MONO_ROOT_SOURCE_GC_HANDLE, "gc handles table");
1532 handles->bitmap = (guint32 *)g_malloc0 (handles->size / CHAR_BIT);
1536 handle_data_next_unset (HandleData *handles)
1539 for (slot = handles->slot_hint; slot < handles->size / BITMAP_SIZE; ++slot) {
1540 if (handles->bitmap [slot] == 0xffffffff)
1542 handles->slot_hint = slot;
1543 return find_first_unset (handles->bitmap [slot]);
1549 handle_data_first_unset (HandleData *handles)
1552 for (slot = 0; slot < handles->slot_hint; ++slot) {
1553 if (handles->bitmap [slot] == 0xffffffff)
1555 handles->slot_hint = slot;
1556 return find_first_unset (handles->bitmap [slot]);
1561 /* Returns the index of the current slot in the bitmap. */
1563 handle_data_grow (HandleData *handles, gboolean track)
1565 guint32 *new_bitmap;
1566 guint32 new_size = handles->size * 2; /* always double: we memset to 0 based on this below */
1568 /* resize and copy the bitmap */
1569 new_bitmap = (guint32 *)g_malloc0 (new_size / CHAR_BIT);
1570 memcpy (new_bitmap, handles->bitmap, handles->size / CHAR_BIT);
1571 g_free (handles->bitmap);
1572 handles->bitmap = new_bitmap;
1574 /* resize and copy the entries */
1575 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1577 guint16 *domain_ids;
1579 domain_ids = (guint16 *)g_malloc0 (sizeof (*handles->domain_ids) * new_size);
1580 entries = (void **)g_malloc0 (sizeof (*handles->entries) * new_size);
1581 memcpy (domain_ids, handles->domain_ids, sizeof (*handles->domain_ids) * handles->size);
1582 for (i = 0; i < handles->size; ++i) {
1583 MonoObject *obj = mono_gc_weak_link_get (&(handles->entries [i]));
1585 mono_gc_weak_link_add (&(entries [i]), obj, track);
1586 mono_gc_weak_link_remove (&(handles->entries [i]), track);
1588 g_assert (!handles->entries [i]);
1591 g_free (handles->entries);
1592 g_free (handles->domain_ids);
1593 handles->entries = entries;
1594 handles->domain_ids = domain_ids;
1597 entries = (void **)mono_gc_alloc_fixed (sizeof (*handles->entries) * new_size, NULL, MONO_ROOT_SOURCE_GC_HANDLE, "gc handles table");
1598 mono_gc_memmove_aligned (entries, handles->entries, sizeof (*handles->entries) * handles->size);
1599 mono_gc_free_fixed (handles->entries);
1600 handles->entries = entries;
1602 handles->slot_hint = handles->size / BITMAP_SIZE;
1603 handles->size = new_size;
1607 alloc_handle (HandleData *handles, MonoObject *obj, gboolean track)
1611 lock_handles (handles);
1613 handle_data_alloc_entries (handles);
1614 i = handle_data_next_unset (handles);
1615 if (i == -1 && handles->slot_hint != 0)
1616 i = handle_data_first_unset (handles);
1618 handle_data_grow (handles, track);
1621 slot = handles->slot_hint * BITMAP_SIZE + i;
1622 occupy_slot (handles, slot);
1623 handles->entries [slot] = NULL;
1624 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1625 /*FIXME, what to use when obj == null?*/
1626 handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
1628 mono_gc_weak_link_add (&(handles->entries [slot]), obj, track);
1630 handles->entries [slot] = obj;
1633 #ifndef DISABLE_PERFCOUNTERS
1634 mono_perfcounters->gc_num_handles++;
1636 unlock_handles (handles);
1637 res = MONO_GC_HANDLE (slot, handles->type);
1638 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_CREATED, handles->type, res, obj);
1643 * mono_gchandle_new:
1644 * @obj: managed object to get a handle for
1645 * @pinned: whether the object should be pinned
1647 * This returns a handle that wraps the object, this is used to keep a
1648 * reference to a managed object from the unmanaged world and preventing the
1649 * object from being disposed.
1651 * If @pinned is false the address of the object can not be obtained, if it is
1652 * true the address of the object can be obtained. This will also pin the
1653 * object so it will not be possible by a moving garbage collector to move the
1656 * Returns: a handle that can be used to access the object from
1660 mono_gchandle_new (MonoObject *obj, gboolean pinned)
1662 return alloc_handle (&gc_handles [pinned? HANDLE_PINNED: HANDLE_NORMAL], obj, FALSE);
1666 * mono_gchandle_new_weakref:
1667 * @obj: managed object to get a handle for
1668 * @pinned: whether the object should be pinned
1670 * This returns a weak handle that wraps the object, this is used to
1671 * keep a reference to a managed object from the unmanaged world.
1672 * Unlike the mono_gchandle_new the object can be reclaimed by the
1673 * garbage collector. In this case the value of the GCHandle will be
1676 * If @pinned is false the address of the object can not be obtained, if it is
1677 * true the address of the object can be obtained. This will also pin the
1678 * object so it will not be possible by a moving garbage collector to move the
1681 * Returns: a handle that can be used to access the object from
1685 mono_gchandle_new_weakref (MonoObject *obj, gboolean track_resurrection)
1687 return alloc_handle (&gc_handles [track_resurrection? HANDLE_WEAK_TRACK: HANDLE_WEAK], obj, track_resurrection);
1691 * mono_gchandle_get_target:
1692 * @gchandle: a GCHandle's handle.
1694 * The handle was previously created by calling mono_gchandle_new or
1695 * mono_gchandle_new_weakref.
1697 * Returns a pointer to the MonoObject represented by the handle or
1698 * NULL for a collected object if using a weakref handle.
1701 mono_gchandle_get_target (guint32 gchandle)
1703 guint slot = MONO_GC_HANDLE_SLOT (gchandle);
1704 guint type = MONO_GC_HANDLE_TYPE (gchandle);
1705 HandleData *handles = &gc_handles [type];
1706 MonoObject *obj = NULL;
1707 if (type >= HANDLE_TYPE_MAX)
1710 lock_handles (handles);
1711 if (slot < handles->size && slot_occupied (handles, slot)) {
1712 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1713 obj = mono_gc_weak_link_get (&handles->entries [slot]);
1715 obj = (MonoObject *)handles->entries [slot];
1718 /* print a warning? */
1720 unlock_handles (handles);
1721 /*g_print ("get target of entry %d of type %d: %p\n", slot, handles->type, obj);*/
1726 mono_gchandle_set_target (guint32 gchandle, MonoObject *obj)
1728 guint slot = MONO_GC_HANDLE_SLOT (gchandle);
1729 guint type = MONO_GC_HANDLE_TYPE (gchandle);
1730 HandleData *handles = &gc_handles [type];
1731 MonoObject *old_obj = NULL;
1733 g_assert (type < HANDLE_TYPE_MAX);
1734 lock_handles (handles);
1735 if (slot < handles->size && slot_occupied (handles, slot)) {
1736 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1737 old_obj = (MonoObject *)handles->entries [slot];
1738 if (handles->entries [slot])
1739 mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
1741 mono_gc_weak_link_add (&handles->entries [slot], obj, handles->type == HANDLE_WEAK_TRACK);
1742 /*FIXME, what to use when obj == null?*/
1743 handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
1745 handles->entries [slot] = obj;
1748 /* print a warning? */
1750 /*g_print ("changed entry %d of type %d to object %p (in slot: %p)\n", slot, handles->type, obj, handles->entries [slot]);*/
1751 unlock_handles (handles);
1755 * mono_gchandle_is_in_domain:
1756 * @gchandle: a GCHandle's handle.
1757 * @domain: An application domain.
1759 * Returns: true if the object wrapped by the @gchandle belongs to the specific @domain.
1762 mono_gc_is_null (void)
1768 mono_gchandle_is_in_domain (guint32 gchandle, MonoDomain *domain)
1770 guint slot = MONO_GC_HANDLE_SLOT (gchandle);
1771 guint type = MONO_GC_HANDLE_TYPE (gchandle);
1772 HandleData *handles = &gc_handles [type];
1773 gboolean result = FALSE;
1775 if (type >= HANDLE_TYPE_MAX)
1778 lock_handles (handles);
1779 if (slot < handles->size && slot_occupied (handles, slot)) {
1780 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1781 result = domain->domain_id == handles->domain_ids [slot];
1784 obj = (MonoObject *)handles->entries [slot];
1788 result = domain == mono_object_domain (obj);
1791 /* print a warning? */
1793 unlock_handles (handles);
1798 * mono_gchandle_free:
1799 * @gchandle: a GCHandle's handle.
1801 * Frees the @gchandle handle. If there are no outstanding
1802 * references, the garbage collector can reclaim the memory of the
1806 mono_gchandle_free (guint32 gchandle)
1808 guint slot = MONO_GC_HANDLE_SLOT (gchandle);
1809 guint type = MONO_GC_HANDLE_TYPE (gchandle);
1810 HandleData *handles = &gc_handles [type];
1811 if (type >= HANDLE_TYPE_MAX)
1814 lock_handles (handles);
1815 if (slot < handles->size && slot_occupied (handles, slot)) {
1816 if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
1817 if (handles->entries [slot])
1818 mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
1820 handles->entries [slot] = NULL;
1822 vacate_slot (handles, slot);
1824 /* print a warning? */
1826 #ifndef DISABLE_PERFCOUNTERS
1827 mono_perfcounters->gc_num_handles--;
1829 /*g_print ("freed entry %d of type %d\n", slot, handles->type);*/
1830 unlock_handles (handles);
1831 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_DESTROYED, handles->type, gchandle, NULL);
1835 * mono_gchandle_free_domain:
1836 * @domain: domain that is unloading
1838 * Function used internally to cleanup any GC handle for objects belonging
1839 * to the specified domain during appdomain unload.
1842 mono_gchandle_free_domain (MonoDomain *domain)
1846 for (type = HANDLE_TYPE_MIN; type < HANDLE_PINNED; ++type) {
1848 HandleData *handles = &gc_handles [type];
1849 lock_handles (handles);
1850 for (slot = 0; slot < handles->size; ++slot) {
1851 if (!slot_occupied (handles, slot))
1853 if (MONO_GC_HANDLE_TYPE_IS_WEAK (type)) {
1854 if (domain->domain_id == handles->domain_ids [slot]) {
1855 vacate_slot (handles, slot);
1856 if (handles->entries [slot])
1857 mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
1860 if (handles->entries [slot] && mono_object_domain (handles->entries [slot]) == domain) {
1861 vacate_slot (handles, slot);
1862 handles->entries [slot] = NULL;
1866 unlock_handles (handles);
1871 #endif /* no Boehm GC */