2 * metadata/gc.c: GC icalls.
4 * Author: Paolo Molaro <lupus@ximian.com>
6 * Copyright 2002-2003 Ximian, Inc (http://www.ximian.com)
7 * Copyright 2004-2009 Novell, Inc (http://www.novell.com)
15 #include <mono/metadata/gc-internal.h>
16 #include <mono/metadata/mono-gc.h>
17 #include <mono/metadata/threads.h>
18 #include <mono/metadata/tabledefs.h>
19 #include <mono/metadata/exception.h>
20 #include <mono/metadata/profiler-private.h>
21 #include <mono/metadata/domain-internals.h>
22 #include <mono/metadata/class-internals.h>
23 #include <mono/metadata/metadata-internals.h>
24 #include <mono/metadata/mono-mlist.h>
25 #include <mono/metadata/threadpool.h>
26 #include <mono/metadata/threads-types.h>
27 #include <mono/utils/mono-logger-internal.h>
28 #include <mono/metadata/gc-internal.h>
29 #include <mono/metadata/marshal.h> /* for mono_delegate_free_ftnptr () */
30 #include <mono/metadata/attach.h>
31 #include <mono/metadata/console-io.h>
32 #include <mono/utils/mono-semaphore.h>
38 typedef struct DomainFinalizationReq {
41 } DomainFinalizationReq;
43 #ifdef PLATFORM_WINCE /* FIXME: add accessors to gc.dll API */
44 extern void (*__imp_GC_finalizer_notifier)(void);
45 #define GC_finalizer_notifier __imp_GC_finalizer_notifier
46 extern int __imp_GC_finalize_on_demand;
47 #define GC_finalize_on_demand __imp_GC_finalize_on_demand
50 static gboolean gc_disabled = FALSE;
52 static gboolean finalizing_root_domain = FALSE;
54 #define mono_finalizer_lock() EnterCriticalSection (&finalizer_mutex)
55 #define mono_finalizer_unlock() LeaveCriticalSection (&finalizer_mutex)
56 static CRITICAL_SECTION finalizer_mutex;
57 static CRITICAL_SECTION reference_queue_mutex;
59 static GSList *domains_to_finalize= NULL;
60 static MonoMList *threads_to_finalize = NULL;
62 static MonoInternalThread *gc_thread;
64 static void object_register_finalizer (MonoObject *obj, void (*callback)(void *, void*));
66 static void mono_gchandle_set_target (guint32 gchandle, MonoObject *obj);
68 static void reference_queue_proccess_all (void);
69 static void mono_reference_queue_cleanup (void);
70 static void reference_queue_clear_for_domain (MonoDomain *domain);
72 static HANDLE pending_done_event;
73 static HANDLE shutdown_event;
77 add_thread_to_finalize (MonoInternalThread *thread)
79 mono_finalizer_lock ();
80 if (!threads_to_finalize)
81 MONO_GC_REGISTER_ROOT_SINGLE (threads_to_finalize);
82 threads_to_finalize = mono_mlist_append (threads_to_finalize, (MonoObject*)thread);
83 mono_finalizer_unlock ();
86 static gboolean suspend_finalizers = FALSE;
88 * actually, we might want to queue the finalize requests in a separate thread,
89 * but we need to be careful about the execution domain of the thread...
92 mono_gc_run_finalize (void *obj, void *data)
94 MonoObject *exc = NULL;
99 MonoMethod* finalizer = NULL;
100 MonoDomain *caller_domain = mono_domain_get ();
102 RuntimeInvokeFunction runtime_invoke;
103 GSList *l, *refs = NULL;
105 o = (MonoObject*)((char*)obj + GPOINTER_TO_UINT (data));
107 if (suspend_finalizers)
110 domain = o->vtable->domain;
113 mono_domain_finalizers_lock (domain);
115 o2 = g_hash_table_lookup (domain->finalizable_objects_hash, o);
117 refs = mono_gc_remove_weak_track_object (domain, o);
119 mono_domain_finalizers_unlock (domain);
122 /* Already finalized somehow */
128 * Support for GCHandles of type WeakTrackResurrection:
130 * Its not exactly clear how these are supposed to work, or how their
131 * semantics can be implemented. We only implement one crucial thing:
132 * these handles are only cleared after the finalizer has ran.
134 for (l = refs; l; l = l->next) {
135 guint32 gchandle = GPOINTER_TO_UINT (l->data);
137 mono_gchandle_set_target (gchandle, o);
143 /* make sure the finalizer is not called again if the object is resurrected */
144 object_register_finalizer (obj, NULL);
146 if (o->vtable->klass == mono_defaults.internal_thread_class) {
147 MonoInternalThread *t = (MonoInternalThread*)o;
149 if (mono_gc_is_finalizer_internal_thread (t))
150 /* Avoid finalizing ourselves */
153 if (t->threadpool_thread && finalizing_root_domain) {
154 /* Don't finalize threadpool threads when
155 shutting down - they're finalized when the
156 threadpool shuts down. */
157 add_thread_to_finalize (t);
162 if (o->vtable->klass->image == mono_defaults.corlib && !strcmp (o->vtable->klass->name, "DynamicMethod") && finalizing_root_domain) {
164 * These can't be finalized during unloading/shutdown, since that would
165 * free the native code which can still be referenced by other
167 * FIXME: This is not perfect, objects dying at the same time as
168 * dynamic methods can still reference them even when !shutdown.
173 if (mono_runtime_get_no_exec ())
176 /* speedup later... and use a timeout */
177 /* g_print ("Finalize run on %p %s.%s\n", o, mono_object_class (o)->name_space, mono_object_class (o)->name); */
179 /* Use _internal here, since this thread can enter a doomed appdomain */
180 mono_domain_set_internal (mono_object_domain (o));
182 /* delegates that have a native function pointer allocated are
183 * registered for finalization, but they don't have a Finalize
184 * method, because in most cases it's not needed and it's just a waste.
186 if (o->vtable->klass->delegate) {
187 MonoDelegate* del = (MonoDelegate*)o;
188 if (del->delegate_trampoline)
189 mono_delegate_free_ftnptr ((MonoDelegate*)o);
190 mono_domain_set_internal (caller_domain);
194 finalizer = mono_class_get_finalizer (o->vtable->klass);
197 /* If object has a CCW but has no finalizer, it was only
198 * registered for finalization in order to free the CCW.
199 * Else it needs the regular finalizer run.
200 * FIXME: what to do about ressurection and suppression
201 * of finalizer on object with CCW.
203 if (mono_marshal_free_ccw (o) && !finalizer) {
204 mono_domain_set_internal (caller_domain);
210 * To avoid the locking plus the other overhead of mono_runtime_invoke (),
211 * create and precompile a wrapper which calls the finalize method using
214 if (!domain->finalize_runtime_invoke) {
215 MonoMethod *invoke = mono_marshal_get_runtime_invoke (mono_class_get_method_from_name_flags (mono_defaults.object_class, "Finalize", 0, 0), TRUE);
217 domain->finalize_runtime_invoke = mono_compile_method (invoke);
220 runtime_invoke = domain->finalize_runtime_invoke;
222 mono_runtime_class_init (o->vtable);
224 runtime_invoke (o, NULL, &exc, NULL);
227 /* fixme: do something useful */
230 mono_domain_set_internal (caller_domain);
234 mono_gc_finalize_threadpool_threads (void)
236 while (threads_to_finalize) {
237 MonoInternalThread *thread = (MonoInternalThread*) mono_mlist_get_data (threads_to_finalize);
239 /* Force finalization of the thread. */
240 thread->threadpool_thread = FALSE;
241 mono_object_register_finalizer ((MonoObject*)thread);
243 mono_gc_run_finalize (thread, NULL);
245 threads_to_finalize = mono_mlist_next (threads_to_finalize);
250 mono_gc_out_of_memory (size_t size)
253 * we could allocate at program startup some memory that we could release
254 * back to the system at this point if we're really low on memory (ie, size is
255 * lower than the memory we set apart)
257 mono_raise_exception (mono_domain_get ()->out_of_memory_ex);
263 * Some of our objects may point to a different address than the address returned by GC_malloc()
264 * (because of the GetHashCode hack), but we need to pass the real address to register_finalizer.
265 * This also means that in the callback we need to adjust the pointer to get back the real
267 * We also need to be consistent in the use of the GC_debug* variants of malloc and register_finalizer,
268 * since that, too, can cause the underlying pointer to be offset.
271 object_register_finalizer (MonoObject *obj, void (*callback)(void *, void*))
278 mono_raise_exception (mono_get_exception_argument_null ("obj"));
280 domain = obj->vtable->domain;
283 /* This assertion is not valid when GC_DEBUG is defined */
284 g_assert (GC_base (obj) == (char*)obj - offset);
287 if (mono_domain_is_unloading (domain) && (callback != NULL))
289 * Can't register finalizers in a dying appdomain, since they
290 * could be invoked after the appdomain has been unloaded.
294 mono_domain_finalizers_lock (domain);
297 g_hash_table_insert (domain->finalizable_objects_hash, obj, obj);
299 g_hash_table_remove (domain->finalizable_objects_hash, obj);
301 mono_domain_finalizers_unlock (domain);
303 GC_REGISTER_FINALIZER_NO_ORDER ((char*)obj - offset, callback, GUINT_TO_POINTER (offset), NULL, NULL);
304 #elif defined(HAVE_SGEN_GC)
306 mono_raise_exception (mono_get_exception_argument_null ("obj"));
309 * If we register finalizers for domains that are unloading we might
310 * end up running them while or after the domain is being cleared, so
311 * the objects will not be valid anymore.
313 if (!mono_domain_is_unloading (obj->vtable->domain))
314 mono_gc_register_for_finalization (obj, callback);
319 * mono_object_register_finalizer:
320 * @obj: object to register
322 * Records that object @obj has a finalizer, this will call the
323 * Finalize method when the garbage collector disposes the object.
327 mono_object_register_finalizer (MonoObject *obj)
329 /* g_print ("Registered finalizer on %p %s.%s\n", obj, mono_object_class (obj)->name_space, mono_object_class (obj)->name); */
330 object_register_finalizer (obj, mono_gc_run_finalize);
334 * mono_domain_finalize:
335 * @domain: the domain to finalize
336 * @timeout: msects to wait for the finalization to complete, -1 to wait indefinitely
338 * Request finalization of all finalizable objects inside @domain. Wait
339 * @timeout msecs for the finalization to complete.
341 * Returns: TRUE if succeeded, FALSE if there was a timeout
345 mono_domain_finalize (MonoDomain *domain, guint32 timeout)
347 DomainFinalizationReq *req;
350 MonoInternalThread *thread = mono_thread_internal_current ();
352 if (mono_thread_internal_current () == gc_thread)
353 /* We are called from inside a finalizer, not much we can do here */
357 * No need to create another thread 'cause the finalizer thread
358 * is still working and will take care of running the finalizers
365 mono_gc_collect (mono_gc_max_generation ());
367 done_event = CreateEvent (NULL, TRUE, FALSE, NULL);
368 if (done_event == NULL) {
372 req = g_new0 (DomainFinalizationReq, 1);
373 req->domain = domain;
374 req->done_event = done_event;
376 if (domain == mono_get_root_domain ())
377 finalizing_root_domain = TRUE;
379 mono_finalizer_lock ();
381 domains_to_finalize = g_slist_append (domains_to_finalize, req);
383 mono_finalizer_unlock ();
385 /* Tell the finalizer thread to finalize this appdomain */
386 mono_gc_finalize_notify ();
392 res = WaitForSingleObjectEx (done_event, timeout, TRUE);
393 /* printf ("WAIT RES: %d.\n", res); */
395 if (res == WAIT_IO_COMPLETION) {
396 if ((thread->state & (ThreadState_StopRequested | ThreadState_SuspendRequested)) != 0)
398 } else if (res == WAIT_TIMEOUT) {
399 /* We leak the handle here */
406 CloseHandle (done_event);
408 if (domain == mono_get_root_domain ()) {
409 mono_thread_pool_cleanup ();
410 mono_gc_finalize_threadpool_threads ();
415 /* We don't support domain finalization without a GC */
421 ves_icall_System_GC_InternalCollect (int generation)
423 mono_gc_collect (generation);
427 ves_icall_System_GC_GetTotalMemory (MonoBoolean forceCollection)
432 mono_gc_collect (mono_gc_max_generation ());
433 return mono_gc_get_used_size ();
437 ves_icall_System_GC_KeepAlive (MonoObject *obj)
447 ves_icall_System_GC_ReRegisterForFinalize (MonoObject *obj)
450 mono_raise_exception (mono_get_exception_argument_null ("obj"));
452 object_register_finalizer (obj, mono_gc_run_finalize);
456 ves_icall_System_GC_SuppressFinalize (MonoObject *obj)
459 mono_raise_exception (mono_get_exception_argument_null ("obj"));
461 /* delegates have no finalizers, but we register them to deal with the
462 * unmanaged->managed trampoline. We don't let the user suppress it
463 * otherwise we'd leak it.
465 if (obj->vtable->klass->delegate)
468 /* FIXME: Need to handle case where obj has COM Callable Wrapper
469 * generated for it that needs cleaned up, but user wants to suppress
470 * their derived object finalizer. */
472 object_register_finalizer (obj, NULL);
476 ves_icall_System_GC_WaitForPendingFinalizers (void)
479 if (!mono_gc_pending_finalizers ())
482 if (mono_thread_internal_current () == gc_thread)
483 /* Avoid deadlocks */
486 ResetEvent (pending_done_event);
487 mono_gc_finalize_notify ();
488 /* g_print ("Waiting for pending finalizers....\n"); */
489 WaitForSingleObjectEx (pending_done_event, INFINITE, TRUE);
490 /* g_print ("Done pending....\n"); */
495 ves_icall_System_GC_register_ephemeron_array (MonoObject *array)
498 if (!mono_gc_ephemeron_array_add (array))
499 mono_raise_exception (mono_object_domain (array)->out_of_memory_ex);
504 ves_icall_System_GC_get_ephemeron_tombstone (void)
506 return mono_domain_get ()->ephemeron_tombstone;
509 #define mono_allocator_lock() EnterCriticalSection (&allocator_section)
510 #define mono_allocator_unlock() LeaveCriticalSection (&allocator_section)
511 static CRITICAL_SECTION allocator_section;
512 static CRITICAL_SECTION handle_section;
521 static HandleType mono_gchandle_get_type (guint32 gchandle);
524 ves_icall_System_GCHandle_GetTarget (guint32 handle)
526 return mono_gchandle_get_target (handle);
530 * if type == -1, change the target of the handle, otherwise allocate a new handle.
533 ves_icall_System_GCHandle_GetTargetHandle (MonoObject *obj, guint32 handle, gint32 type)
536 mono_gchandle_set_target (handle, obj);
537 /* the handle doesn't change */
542 return mono_gchandle_new_weakref (obj, FALSE);
543 case HANDLE_WEAK_TRACK:
544 return mono_gchandle_new_weakref (obj, TRUE);
546 return mono_gchandle_new (obj, FALSE);
548 return mono_gchandle_new (obj, TRUE);
550 g_assert_not_reached ();
556 ves_icall_System_GCHandle_FreeHandle (guint32 handle)
558 mono_gchandle_free (handle);
562 ves_icall_System_GCHandle_GetAddrOfPinnedObject (guint32 handle)
566 if (mono_gchandle_get_type (handle) != HANDLE_PINNED)
568 obj = mono_gchandle_get_target (handle);
570 MonoClass *klass = mono_object_class (obj);
571 if (klass == mono_defaults.string_class) {
572 return mono_string_chars ((MonoString*)obj);
573 } else if (klass->rank) {
574 return mono_array_addr ((MonoArray*)obj, char, 0);
576 /* the C# code will check and throw the exception */
577 /* FIXME: missing !klass->blittable test, see bug #61134 */
578 if ((klass->flags & TYPE_ATTRIBUTE_LAYOUT_MASK) == TYPE_ATTRIBUTE_AUTO_LAYOUT)
580 return (char*)obj + sizeof (MonoObject);
591 guint slot_hint : 24; /* starting slot for search */
592 /* 2^16 appdomains should be enough for everyone (though I know I'll regret this in 20 years) */
593 /* we alloc this only for weak refs, since we can get the domain directly in the other cases */
597 /* weak and weak-track arrays will be allocated in malloc memory
599 static HandleData gc_handles [] = {
600 {NULL, NULL, 0, HANDLE_WEAK, 0},
601 {NULL, NULL, 0, HANDLE_WEAK_TRACK, 0},
602 {NULL, NULL, 0, HANDLE_NORMAL, 0},
603 {NULL, NULL, 0, HANDLE_PINNED, 0}
606 #define lock_handles(handles) EnterCriticalSection (&handle_section)
607 #define unlock_handles(handles) LeaveCriticalSection (&handle_section)
610 find_first_unset (guint32 bitmap)
613 for (i = 0; i < 32; ++i) {
614 if (!(bitmap & (1 << i)))
621 alloc_handle (HandleData *handles, MonoObject *obj, gboolean track)
625 lock_handles (handles);
626 if (!handles->size) {
628 if (handles->type > HANDLE_WEAK_TRACK) {
629 handles->entries = mono_gc_alloc_fixed (sizeof (gpointer) * handles->size, mono_gc_make_root_descr_all_refs (handles->size));
631 handles->entries = g_malloc0 (sizeof (gpointer) * handles->size);
632 handles->domain_ids = g_malloc0 (sizeof (guint16) * handles->size);
634 handles->bitmap = g_malloc0 (handles->size / 8);
637 for (slot = handles->slot_hint; slot < handles->size / 32; ++slot) {
638 if (handles->bitmap [slot] != 0xffffffff) {
639 i = find_first_unset (handles->bitmap [slot]);
640 handles->slot_hint = slot;
644 if (i == -1 && handles->slot_hint != 0) {
645 for (slot = 0; slot < handles->slot_hint; ++slot) {
646 if (handles->bitmap [slot] != 0xffffffff) {
647 i = find_first_unset (handles->bitmap [slot]);
648 handles->slot_hint = slot;
655 guint32 new_size = handles->size * 2; /* always double: we memset to 0 based on this below */
657 /* resize and copy the bitmap */
658 new_bitmap = g_malloc0 (new_size / 8);
659 memcpy (new_bitmap, handles->bitmap, handles->size / 8);
660 g_free (handles->bitmap);
661 handles->bitmap = new_bitmap;
663 /* resize and copy the entries */
664 if (handles->type > HANDLE_WEAK_TRACK) {
667 entries = mono_gc_alloc_fixed (sizeof (gpointer) * new_size, mono_gc_make_root_descr_all_refs (new_size));
668 memcpy (entries, handles->entries, sizeof (gpointer) * handles->size);
670 mono_gc_free_fixed (handles->entries);
671 handles->entries = entries;
675 domain_ids = g_malloc0 (sizeof (guint16) * new_size);
676 entries = g_malloc (sizeof (gpointer) * new_size);
677 /* we disable GC because we could lose some disappearing link updates */
679 memcpy (entries, handles->entries, sizeof (gpointer) * handles->size);
680 memset (entries + handles->size, 0, sizeof (gpointer) * handles->size);
681 memcpy (domain_ids, handles->domain_ids, sizeof (guint16) * handles->size);
682 for (i = 0; i < handles->size; ++i) {
683 MonoObject *obj = mono_gc_weak_link_get (&(handles->entries [i]));
684 if (handles->entries [i])
685 mono_gc_weak_link_remove (&(handles->entries [i]));
686 /*g_print ("reg/unreg entry %d of type %d at %p to object %p (%p), was: %p\n", i, handles->type, &(entries [i]), obj, entries [i], handles->entries [i]);*/
688 mono_gc_weak_link_add (&(entries [i]), obj, track);
691 g_free (handles->entries);
692 g_free (handles->domain_ids);
693 handles->entries = entries;
694 handles->domain_ids = domain_ids;
698 /* set i and slot to the next free position */
700 slot = (handles->size + 1) / 32;
701 handles->slot_hint = handles->size + 1;
702 handles->size = new_size;
704 handles->bitmap [slot] |= 1 << i;
705 slot = slot * 32 + i;
706 handles->entries [slot] = obj;
707 if (handles->type <= HANDLE_WEAK_TRACK) {
708 /*FIXME, what to use when obj == null?*/
709 handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
711 mono_gc_weak_link_add (&(handles->entries [slot]), obj, track);
714 mono_perfcounters->gc_num_handles++;
715 unlock_handles (handles);
716 /*g_print ("allocated entry %d of type %d to object %p (in slot: %p)\n", slot, handles->type, obj, handles->entries [slot]);*/
717 res = (slot << 3) | (handles->type + 1);
718 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_CREATED, handles->type, res, obj);
724 * @obj: managed object to get a handle for
725 * @pinned: whether the object should be pinned
727 * This returns a handle that wraps the object, this is used to keep a
728 * reference to a managed object from the unmanaged world and preventing the
729 * object from being disposed.
731 * If @pinned is false the address of the object can not be obtained, if it is
732 * true the address of the object can be obtained. This will also pin the
733 * object so it will not be possible by a moving garbage collector to move the
736 * Returns: a handle that can be used to access the object from
740 mono_gchandle_new (MonoObject *obj, gboolean pinned)
742 return alloc_handle (&gc_handles [pinned? HANDLE_PINNED: HANDLE_NORMAL], obj, FALSE);
746 * mono_gchandle_new_weakref:
747 * @obj: managed object to get a handle for
748 * @pinned: whether the object should be pinned
750 * This returns a weak handle that wraps the object, this is used to
751 * keep a reference to a managed object from the unmanaged world.
752 * Unlike the mono_gchandle_new the object can be reclaimed by the
753 * garbage collector. In this case the value of the GCHandle will be
756 * If @pinned is false the address of the object can not be obtained, if it is
757 * true the address of the object can be obtained. This will also pin the
758 * object so it will not be possible by a moving garbage collector to move the
761 * Returns: a handle that can be used to access the object from
765 mono_gchandle_new_weakref (MonoObject *obj, gboolean track_resurrection)
767 guint32 handle = alloc_handle (&gc_handles [track_resurrection? HANDLE_WEAK_TRACK: HANDLE_WEAK], obj, track_resurrection);
770 if (track_resurrection)
771 mono_gc_add_weak_track_handle (obj, handle);
778 mono_gchandle_get_type (guint32 gchandle)
780 guint type = (gchandle & 7) - 1;
786 * mono_gchandle_get_target:
787 * @gchandle: a GCHandle's handle.
789 * The handle was previously created by calling mono_gchandle_new or
790 * mono_gchandle_new_weakref.
792 * Returns a pointer to the MonoObject represented by the handle or
793 * NULL for a collected object if using a weakref handle.
796 mono_gchandle_get_target (guint32 gchandle)
798 guint slot = gchandle >> 3;
799 guint type = (gchandle & 7) - 1;
800 HandleData *handles = &gc_handles [type];
801 MonoObject *obj = NULL;
804 lock_handles (handles);
805 if (slot < handles->size && (handles->bitmap [slot / 32] & (1 << (slot % 32)))) {
806 if (handles->type <= HANDLE_WEAK_TRACK) {
807 obj = mono_gc_weak_link_get (&handles->entries [slot]);
809 obj = handles->entries [slot];
812 /* print a warning? */
814 unlock_handles (handles);
815 /*g_print ("get target of entry %d of type %d: %p\n", slot, handles->type, obj);*/
820 mono_gchandle_set_target (guint32 gchandle, MonoObject *obj)
822 guint slot = gchandle >> 3;
823 guint type = (gchandle & 7) - 1;
824 HandleData *handles = &gc_handles [type];
825 MonoObject *old_obj = NULL;
829 lock_handles (handles);
830 if (slot < handles->size && (handles->bitmap [slot / 32] & (1 << (slot % 32)))) {
831 if (handles->type <= HANDLE_WEAK_TRACK) {
832 old_obj = handles->entries [slot];
833 if (handles->entries [slot])
834 mono_gc_weak_link_remove (&handles->entries [slot]);
836 mono_gc_weak_link_add (&handles->entries [slot], obj, handles->type == HANDLE_WEAK_TRACK);
837 /*FIXME, what to use when obj == null?*/
838 handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
840 handles->entries [slot] = obj;
843 /* print a warning? */
845 /*g_print ("changed entry %d of type %d to object %p (in slot: %p)\n", slot, handles->type, obj, handles->entries [slot]);*/
846 unlock_handles (handles);
849 if (type == HANDLE_WEAK_TRACK)
850 mono_gc_change_weak_track_handle (old_obj, obj, gchandle);
855 * mono_gchandle_is_in_domain:
856 * @gchandle: a GCHandle's handle.
857 * @domain: An application domain.
859 * Returns: true if the object wrapped by the @gchandle belongs to the specific @domain.
862 mono_gchandle_is_in_domain (guint32 gchandle, MonoDomain *domain)
864 guint slot = gchandle >> 3;
865 guint type = (gchandle & 7) - 1;
866 HandleData *handles = &gc_handles [type];
867 gboolean result = FALSE;
870 lock_handles (handles);
871 if (slot < handles->size && (handles->bitmap [slot / 32] & (1 << (slot % 32)))) {
872 if (handles->type <= HANDLE_WEAK_TRACK) {
873 result = domain->domain_id == handles->domain_ids [slot];
876 obj = handles->entries [slot];
880 result = domain == mono_object_domain (obj);
883 /* print a warning? */
885 unlock_handles (handles);
890 * mono_gchandle_free:
891 * @gchandle: a GCHandle's handle.
893 * Frees the @gchandle handle. If there are no outstanding
894 * references, the garbage collector can reclaim the memory of the
898 mono_gchandle_free (guint32 gchandle)
900 guint slot = gchandle >> 3;
901 guint type = (gchandle & 7) - 1;
902 HandleData *handles = &gc_handles [type];
906 if (type == HANDLE_WEAK_TRACK)
907 mono_gc_remove_weak_track_handle (gchandle);
910 lock_handles (handles);
911 if (slot < handles->size && (handles->bitmap [slot / 32] & (1 << (slot % 32)))) {
912 if (handles->type <= HANDLE_WEAK_TRACK) {
913 if (handles->entries [slot])
914 mono_gc_weak_link_remove (&handles->entries [slot]);
916 handles->entries [slot] = NULL;
918 handles->bitmap [slot / 32] &= ~(1 << (slot % 32));
920 /* print a warning? */
922 mono_perfcounters->gc_num_handles--;
923 /*g_print ("freed entry %d of type %d\n", slot, handles->type);*/
924 unlock_handles (handles);
925 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_DESTROYED, handles->type, gchandle, NULL);
929 * mono_gchandle_free_domain:
930 * @domain: domain that is unloading
932 * Function used internally to cleanup any GC handle for objects belonging
933 * to the specified domain during appdomain unload.
936 mono_gchandle_free_domain (MonoDomain *domain)
940 for (type = 0; type < 3; ++type) {
942 HandleData *handles = &gc_handles [type];
943 lock_handles (handles);
944 for (slot = 0; slot < handles->size; ++slot) {
945 if (!(handles->bitmap [slot / 32] & (1 << (slot % 32))))
947 if (type <= HANDLE_WEAK_TRACK) {
948 if (domain->domain_id == handles->domain_ids [slot]) {
949 handles->bitmap [slot / 32] &= ~(1 << (slot % 32));
950 if (handles->entries [slot])
951 mono_gc_weak_link_remove (&handles->entries [slot]);
954 if (handles->entries [slot] && mono_object_domain (handles->entries [slot]) == domain) {
955 handles->bitmap [slot / 32] &= ~(1 << (slot % 32));
956 handles->entries [slot] = NULL;
960 unlock_handles (handles);
966 GCHandle_CheckCurrentDomain (guint32 gchandle)
968 return mono_gchandle_is_in_domain (gchandle, mono_domain_get ());
973 #ifdef MONO_HAS_SEMAPHORES
974 static MonoSemType finalizer_sem;
976 static HANDLE finalizer_event;
977 static volatile gboolean finished=FALSE;
980 mono_gc_finalize_notify (void)
983 g_message ( "%s: prodding finalizer", __func__);
986 #ifdef MONO_HAS_SEMAPHORES
987 MONO_SEM_POST (&finalizer_sem);
989 SetEvent (finalizer_event);
996 collect_objects (gpointer key, gpointer value, gpointer user_data)
998 GPtrArray *arr = (GPtrArray*)user_data;
999 g_ptr_array_add (arr, key);
1005 * finalize_domain_objects:
1007 * Run the finalizers of all finalizable objects in req->domain.
1010 finalize_domain_objects (DomainFinalizationReq *req)
1012 MonoDomain *domain = req->domain;
1014 #ifdef HAVE_BOEHM_GC
1015 while (g_hash_table_size (domain->finalizable_objects_hash) > 0) {
1019 * Since the domain is unloading, nobody is allowed to put
1020 * new entries into the hash table. But finalize_object might
1021 * remove entries from the hash table, so we make a copy.
1023 objs = g_ptr_array_new ();
1024 g_hash_table_foreach (domain->finalizable_objects_hash, collect_objects, objs);
1025 /* printf ("FINALIZING %d OBJECTS.\n", objs->len); */
1027 for (i = 0; i < objs->len; ++i) {
1028 MonoObject *o = (MonoObject*)g_ptr_array_index (objs, i);
1029 /* FIXME: Avoid finalizing threads, etc */
1030 mono_gc_run_finalize (o, 0);
1033 g_ptr_array_free (objs, TRUE);
1035 #elif defined(HAVE_SGEN_GC)
1036 #define NUM_FOBJECTS 64
1037 MonoObject *to_finalize [NUM_FOBJECTS];
1039 while ((count = mono_gc_finalizers_for_domain (domain, to_finalize, NUM_FOBJECTS))) {
1041 for (i = 0; i < count; ++i) {
1042 mono_gc_run_finalize (to_finalize [i], 0);
1047 /* Process finalizers which are already in the queue */
1048 mono_gc_invoke_finalizers ();
1050 /* cleanup the reference queue */
1051 reference_queue_clear_for_domain (domain);
1053 /* printf ("DONE.\n"); */
1054 SetEvent (req->done_event);
1056 /* The event is closed in mono_domain_finalize if we get here */
1061 finalizer_thread (gpointer unused)
1064 /* Wait to be notified that there's at least one
1068 g_assert (mono_domain_get () == mono_get_root_domain ());
1070 /* An alertable wait is required so this thread can be suspended on windows */
1071 #ifdef MONO_HAS_SEMAPHORES
1072 MONO_SEM_WAIT_ALERTABLE (&finalizer_sem, TRUE);
1074 WaitForSingleObjectEx (finalizer_event, INFINITE, TRUE);
1077 mono_threads_perform_thread_dump ();
1079 mono_console_handle_async_ops ();
1081 #ifndef DISABLE_ATTACH
1082 mono_attach_maybe_start ();
1085 if (domains_to_finalize) {
1086 mono_finalizer_lock ();
1087 if (domains_to_finalize) {
1088 DomainFinalizationReq *req = domains_to_finalize->data;
1089 domains_to_finalize = g_slist_remove (domains_to_finalize, req);
1090 mono_finalizer_unlock ();
1092 finalize_domain_objects (req);
1094 mono_finalizer_unlock ();
1098 /* If finished == TRUE, mono_gc_cleanup has been called (from mono_runtime_cleanup),
1099 * before the domain is unloaded.
1101 mono_gc_invoke_finalizers ();
1103 reference_queue_proccess_all ();
1105 SetEvent (pending_done_event);
1108 SetEvent (shutdown_event);
1115 InitializeCriticalSection (&handle_section);
1116 InitializeCriticalSection (&allocator_section);
1118 InitializeCriticalSection (&finalizer_mutex);
1119 InitializeCriticalSection (&reference_queue_mutex);
1121 MONO_GC_REGISTER_ROOT_FIXED (gc_handles [HANDLE_NORMAL].entries);
1122 MONO_GC_REGISTER_ROOT_FIXED (gc_handles [HANDLE_PINNED].entries);
1124 mono_gc_base_init ();
1126 if (mono_gc_is_disabled ()) {
1131 finalizer_event = CreateEvent (NULL, FALSE, FALSE, NULL);
1132 pending_done_event = CreateEvent (NULL, TRUE, FALSE, NULL);
1133 shutdown_event = CreateEvent (NULL, TRUE, FALSE, NULL);
1134 if (finalizer_event == NULL || pending_done_event == NULL || shutdown_event == NULL) {
1135 g_assert_not_reached ();
1137 #ifdef MONO_HAS_SEMAPHORES
1138 MONO_SEM_INIT (&finalizer_sem, 0);
1141 gc_thread = mono_thread_create_internal (mono_domain_get (), finalizer_thread, NULL, FALSE, 0);
1142 ves_icall_System_Threading_Thread_SetName_internal (gc_thread, mono_string_new (mono_domain_get (), "Finalizer"));
1146 mono_gc_cleanup (void)
1149 g_message ("%s: cleaning up finalizer", __func__);
1153 ResetEvent (shutdown_event);
1155 if (mono_thread_internal_current () != gc_thread) {
1156 mono_gc_finalize_notify ();
1157 /* Finishing the finalizer thread, so wait a little bit... */
1158 /* MS seems to wait for about 2 seconds */
1159 if (WaitForSingleObjectEx (shutdown_event, 2000, FALSE) == WAIT_TIMEOUT) {
1162 /* Set a flag which the finalizer thread can check */
1163 suspend_finalizers = TRUE;
1165 /* Try to abort the thread, in the hope that it is running managed code */
1166 mono_thread_internal_stop (gc_thread);
1168 /* Wait for it to stop */
1169 ret = WaitForSingleObjectEx (gc_thread->handle, 100, TRUE);
1171 if (ret == WAIT_TIMEOUT) {
1173 * The finalizer thread refused to die. There is not much we
1174 * can do here, since the runtime is shutting down so the
1175 * state the finalizer thread depends on will vanish.
1177 g_warning ("Shutting down finalizer thread timed out.");
1180 * FIXME: On unix, when the above wait returns, the thread
1181 * might still be running io-layer code, or pthreads code.
1189 #ifdef HAVE_BOEHM_GC
1190 GC_finalizer_notifier = NULL;
1194 mono_reference_queue_cleanup ();
1196 DeleteCriticalSection (&handle_section);
1197 DeleteCriticalSection (&allocator_section);
1198 DeleteCriticalSection (&finalizer_mutex);
1199 DeleteCriticalSection (&reference_queue_mutex);
1204 /* Null GC dummy functions */
1206 mono_gc_finalize_notify (void)
1210 void mono_gc_init (void)
1212 InitializeCriticalSection (&handle_section);
1215 void mono_gc_cleanup (void)
1222 mono_gc_is_finalizer_internal_thread (MonoInternalThread *thread)
1224 return thread == gc_thread;
1228 * mono_gc_is_finalizer_thread:
1229 * @thread: the thread to test.
1231 * In Mono objects are finalized asynchronously on a separate thread.
1232 * This routine tests whether the @thread argument represents the
1233 * finalization thread.
1235 * Returns true if @thread is the finalization thread.
1238 mono_gc_is_finalizer_thread (MonoThread *thread)
1240 return mono_gc_is_finalizer_internal_thread (thread->internal_thread);
1243 #if defined(__MACH__)
1244 static pthread_t mach_exception_thread;
1247 mono_gc_register_mach_exception_thread (pthread_t thread)
1249 mach_exception_thread = thread;
1253 mono_gc_get_mach_exception_thread (void)
1255 return mach_exception_thread;
1260 * mono_gc_parse_environment_string_extract_number:
1262 * @str: points to the first digit of the number
1263 * @out: pointer to the variable that will receive the value
1265 * Tries to extract a number from the passed string, taking in to account m, k
1268 * Returns true if passing was successful
1271 mono_gc_parse_environment_string_extract_number (const char *str, glong *out)
1274 int len = strlen (str), shift = 0;
1276 gboolean is_suffix = FALSE;
1279 switch (str [len - 1]) {
1290 suffix = str [len - 1];
1295 val = strtol (str, &endptr, 10);
1297 if ((errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
1298 || (errno != 0 && val == 0) || (endptr == str))
1302 if (*(endptr + 1)) /* Invalid string. */
1311 #ifndef HAVE_SGEN_GC
1313 mono_gc_alloc_mature (MonoVTable *vtable)
1315 return mono_object_new_specific (vtable);
1320 static MonoReferenceQueue *ref_queues;
1323 ref_list_remove_element (RefQueueEntry **prev, RefQueueEntry *element)
1326 /* Guard if head is changed concurrently. */
1327 while (*prev != element)
1328 prev = &(*prev)->next;
1329 } while (prev && InterlockedCompareExchangePointer ((void*)prev, element->next, element) != element);
1333 ref_list_push (RefQueueEntry **head, RefQueueEntry *value)
1335 RefQueueEntry *current;
1338 value->next = current;
1339 } while (InterlockedCompareExchangePointer ((void*)head, value, current) != current);
1343 reference_queue_proccess (MonoReferenceQueue *queue)
1345 RefQueueEntry **iter = &queue->queue;
1346 RefQueueEntry *entry;
1347 while ((entry = *iter)) {
1349 if (queue->should_be_deleted || !mono_gc_weak_link_get (&entry->dis_link)) {
1350 mono_gc_weak_link_remove (&entry->dis_link);
1352 if (queue->should_be_deleted || !mono_gchandle_get_target (entry->gchandle)) {
1353 mono_gchandle_free ((guint32)entry->gchandle);
1355 ref_list_remove_element (iter, entry);
1356 queue->callback (entry->user_data);
1359 iter = &entry->next;
1365 reference_queue_proccess_all (void)
1367 MonoReferenceQueue **iter;
1368 MonoReferenceQueue *queue = ref_queues;
1369 for (; queue; queue = queue->next)
1370 reference_queue_proccess (queue);
1373 EnterCriticalSection (&reference_queue_mutex);
1374 for (iter = &ref_queues; *iter;) {
1376 if (!queue->should_be_deleted) {
1377 iter = &queue->next;
1381 LeaveCriticalSection (&reference_queue_mutex);
1382 reference_queue_proccess (queue);
1385 *iter = queue->next;
1388 LeaveCriticalSection (&reference_queue_mutex);
1392 mono_reference_queue_cleanup (void)
1394 MonoReferenceQueue *queue = ref_queues;
1395 for (; queue; queue = queue->next)
1396 queue->should_be_deleted = TRUE;
1397 reference_queue_proccess_all ();
1401 reference_queue_clear_for_domain (MonoDomain *domain)
1403 MonoReferenceQueue *queue = ref_queues;
1404 for (; queue; queue = queue->next) {
1405 RefQueueEntry **iter = &queue->queue;
1406 RefQueueEntry *entry;
1407 while ((entry = *iter)) {
1410 obj = mono_gc_weak_link_get (&entry->dis_link);
1411 if (obj && mono_object_domain (obj) == domain) {
1412 mono_gc_weak_link_remove (&entry->dis_link);
1414 obj = mono_gchandle_get_target (entry->gchandle);
1415 if (obj && mono_object_domain (obj) == domain) {
1416 mono_gchandle_free ((guint32)entry->gchandle);
1418 ref_list_remove_element (iter, entry);
1419 queue->callback (entry->user_data);
1422 iter = &entry->next;
1428 * mono_gc_reference_queue_new:
1429 * @callback callback used when processing dead entries.
1431 * Create a new reference queue used to process collected objects.
1432 * A reference queue let you queue the pair (managed object, user data).
1433 * Once the managed object is collected @callback will be called
1434 * in the finalizer thread with 'user data' as argument.
1436 * The callback is called without any locks held.
1439 mono_gc_reference_queue_new (mono_reference_queue_callback callback)
1441 MonoReferenceQueue *res = g_new0 (MonoReferenceQueue, 1);
1442 res->callback = callback;
1444 EnterCriticalSection (&reference_queue_mutex);
1445 res->next = ref_queues;
1447 LeaveCriticalSection (&reference_queue_mutex);
1453 * mono_gc_reference_queue_add:
1454 * @queue the queue to add the reference to.
1455 * @obj the object to be watched for collection
1456 * @user_data parameter to be passed to the queue callback
1458 * Queue an object to be watched for collection.
1460 * @returns false if the queue is scheduled to be freed.
1463 mono_gc_reference_queue_add (MonoReferenceQueue *queue, MonoObject *obj, void *user_data)
1465 RefQueueEntry *entry;
1466 if (queue->should_be_deleted)
1469 entry = g_new0 (RefQueueEntry, 1);
1470 entry->user_data = user_data;
1473 mono_gc_weak_link_add (&entry->dis_link, obj, TRUE);
1475 entry->gchandle = mono_gchandle_new_weakref (obj, TRUE);
1476 mono_object_register_finalizer (obj);
1479 ref_list_push (&queue->queue, entry);
1484 * mono_gc_reference_queue_free:
1485 * @queue the queue that should be deleted.
1487 * This operation signals that @queue should be deleted. This operation is deferred
1488 * as it happens on the finalizer thread.
1490 * After this call, no further objects can be queued. It's the responsibility of the
1491 * caller to make sure that no further attempt to access queue will be made.
1494 mono_gc_reference_queue_free (MonoReferenceQueue *queue)
1496 queue->should_be_deleted = TRUE;
1499 #define ptr_mask ((sizeof (void*) - 1))
1500 #define _toi(ptr) ((size_t)ptr)
1501 #define unaligned_bytes(ptr) (_toi(ptr) & ptr_mask)
1502 #define aligned_end(ptr) ((void*)(_toi(ptr) & ~ptr_mask))
1503 #define align_up(ptr) ((void*) ((_toi(ptr) + ptr_mask) & ~ptr_mask))
1506 * Zero @size bytes starting at @dest.
1508 * Use this to zero memory that can hold managed pointers.
1510 * FIXME borrow faster code from some BSD libc or bionic
1513 mono_gc_bzero (void *dest, size_t size)
1515 char *p = (char*)dest;
1516 char *end = p + size;
1517 char *align_end = p + unaligned_bytes (p);
1520 while (p < align_end)
1523 word_end = aligned_end (end);
1524 while (p < word_end) {
1525 *((void**)p) = NULL;
1526 p += sizeof (void*);
1535 * Move @size bytes from @src to @dest.
1536 * size MUST be a multiple of sizeof (gpointer)
1538 * FIXME borrow faster code from some BSD libc or bionic
1541 mono_gc_memmove (void *dest, const void *src, size_t size)
1544 * A bit of explanation on why we align only dest before doing word copies.
1545 * Pointers to managed objects must always be stored in word aligned addresses, so
1546 * even if dest is misaligned, src will be by the same amount - this ensure proper atomicity of reads.
1549 /*potentially overlap, do a backward copy*/
1551 char *p = (char*)dest + size;
1552 char *s = (char*)src + size;
1553 char *start = (char*)dest;
1554 char *align_end = aligned_end (p);
1557 while (p > align_end)
1560 word_start = align_up (start);
1561 while (p > word_start) {
1562 p -= sizeof (void*);
1563 s -= sizeof (void*);
1564 *((void**)p) = *((void**)s);
1570 char *p = (char*)dest;
1571 char *s = (char*)src;
1572 char *end = p + size;
1573 char *align_end = p + unaligned_bytes (p);
1576 while (p < align_end)
1579 word_end = aligned_end (end);
1580 while (p < word_end) {
1581 *((void**)p) = *((void**)s);
1582 p += sizeof (void*);
1583 s += sizeof (void*);