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)
8 * Copyright 2012 Xamarin Inc (http://www.xamarin.com)
16 #include <mono/metadata/gc-internal.h>
17 #include <mono/metadata/mono-gc.h>
18 #include <mono/metadata/threads.h>
19 #include <mono/metadata/tabledefs.h>
20 #include <mono/metadata/exception.h>
21 #include <mono/metadata/profiler-private.h>
22 #include <mono/metadata/domain-internals.h>
23 #include <mono/metadata/class-internals.h>
24 #include <mono/metadata/metadata-internals.h>
25 #include <mono/metadata/mono-mlist.h>
26 #include <mono/metadata/threadpool.h>
27 #include <mono/metadata/threadpool-internals.h>
28 #include <mono/metadata/threads-types.h>
29 #include <mono/utils/mono-logger-internal.h>
30 #include <mono/metadata/gc-internal.h>
31 #include <mono/metadata/marshal.h> /* for mono_delegate_free_ftnptr () */
32 #include <mono/metadata/attach.h>
33 #include <mono/metadata/console-io.h>
34 #include <mono/utils/mono-semaphore.h>
35 #include <mono/utils/mono-memory-model.h>
36 #include <mono/utils/mono-counters.h>
37 #include <mono/utils/dtrace.h>
43 typedef struct DomainFinalizationReq {
46 } DomainFinalizationReq;
48 #ifdef PLATFORM_WINCE /* FIXME: add accessors to gc.dll API */
49 extern void (*__imp_GC_finalizer_notifier)(void);
50 #define GC_finalizer_notifier __imp_GC_finalizer_notifier
51 extern int __imp_GC_finalize_on_demand;
52 #define GC_finalize_on_demand __imp_GC_finalize_on_demand
55 static gboolean gc_disabled = FALSE;
57 static gboolean finalizing_root_domain = FALSE;
59 #define mono_finalizer_lock() EnterCriticalSection (&finalizer_mutex)
60 #define mono_finalizer_unlock() LeaveCriticalSection (&finalizer_mutex)
61 static CRITICAL_SECTION finalizer_mutex;
62 static CRITICAL_SECTION reference_queue_mutex;
64 static GSList *domains_to_finalize= NULL;
65 static MonoMList *threads_to_finalize = NULL;
67 static MonoInternalThread *gc_thread;
69 static void object_register_finalizer (MonoObject *obj, void (*callback)(void *, void*));
71 static void mono_gchandle_set_target (guint32 gchandle, MonoObject *obj);
73 static void reference_queue_proccess_all (void);
74 static void mono_reference_queue_cleanup (void);
75 static void reference_queue_clear_for_domain (MonoDomain *domain);
77 static HANDLE pending_done_event;
78 static HANDLE shutdown_event;
84 add_thread_to_finalize (MonoInternalThread *thread)
86 mono_finalizer_lock ();
87 if (!threads_to_finalize)
88 MONO_GC_REGISTER_ROOT_SINGLE (threads_to_finalize);
89 threads_to_finalize = mono_mlist_append (threads_to_finalize, (MonoObject*)thread);
90 mono_finalizer_unlock ();
93 static gboolean suspend_finalizers = FALSE;
95 * actually, we might want to queue the finalize requests in a separate thread,
96 * but we need to be careful about the execution domain of the thread...
99 mono_gc_run_finalize (void *obj, void *data)
101 MonoObject *exc = NULL;
106 MonoMethod* finalizer = NULL;
107 MonoDomain *caller_domain = mono_domain_get ();
109 RuntimeInvokeFunction runtime_invoke;
111 o = (MonoObject*)((char*)obj + GPOINTER_TO_UINT (data));
113 if (suspend_finalizers)
116 domain = o->vtable->domain;
119 mono_domain_finalizers_lock (domain);
121 o2 = g_hash_table_lookup (domain->finalizable_objects_hash, o);
123 mono_domain_finalizers_unlock (domain);
126 /* Already finalized somehow */
130 /* make sure the finalizer is not called again if the object is resurrected */
131 object_register_finalizer (obj, NULL);
133 if (o->vtable->klass == mono_defaults.internal_thread_class) {
134 MonoInternalThread *t = (MonoInternalThread*)o;
136 if (mono_gc_is_finalizer_internal_thread (t))
137 /* Avoid finalizing ourselves */
140 if (t->threadpool_thread && finalizing_root_domain) {
141 /* Don't finalize threadpool threads when
142 shutting down - they're finalized when the
143 threadpool shuts down. */
144 add_thread_to_finalize (t);
149 if (o->vtable->klass->image == mono_defaults.corlib && !strcmp (o->vtable->klass->name, "DynamicMethod") && finalizing_root_domain) {
151 * These can't be finalized during unloading/shutdown, since that would
152 * free the native code which can still be referenced by other
154 * FIXME: This is not perfect, objects dying at the same time as
155 * dynamic methods can still reference them even when !shutdown.
160 if (mono_runtime_get_no_exec ())
163 /* speedup later... and use a timeout */
164 /* g_print ("Finalize run on %p %s.%s\n", o, mono_object_class (o)->name_space, mono_object_class (o)->name); */
166 /* Use _internal here, since this thread can enter a doomed appdomain */
167 mono_domain_set_internal (mono_object_domain (o));
169 /* delegates that have a native function pointer allocated are
170 * registered for finalization, but they don't have a Finalize
171 * method, because in most cases it's not needed and it's just a waste.
173 if (o->vtable->klass->delegate) {
174 MonoDelegate* del = (MonoDelegate*)o;
175 if (del->delegate_trampoline)
176 mono_delegate_free_ftnptr ((MonoDelegate*)o);
177 mono_domain_set_internal (caller_domain);
181 finalizer = mono_class_get_finalizer (o->vtable->klass);
184 /* If object has a CCW but has no finalizer, it was only
185 * registered for finalization in order to free the CCW.
186 * Else it needs the regular finalizer run.
187 * FIXME: what to do about ressurection and suppression
188 * of finalizer on object with CCW.
190 if (mono_marshal_free_ccw (o) && !finalizer) {
191 mono_domain_set_internal (caller_domain);
197 * To avoid the locking plus the other overhead of mono_runtime_invoke (),
198 * create and precompile a wrapper which calls the finalize method using
201 if (!domain->finalize_runtime_invoke) {
202 MonoMethod *invoke = mono_marshal_get_runtime_invoke (mono_class_get_method_from_name_flags (mono_defaults.object_class, "Finalize", 0, 0), TRUE);
204 domain->finalize_runtime_invoke = mono_compile_method (invoke);
207 runtime_invoke = domain->finalize_runtime_invoke;
209 mono_runtime_class_init (o->vtable);
211 if (G_UNLIKELY (MONO_GC_FINALIZE_INVOKE_ENABLED ())) {
212 MONO_GC_FINALIZE_INVOKE ((unsigned long)o, mono_object_get_size (o),
213 o->vtable->klass->name_space, o->vtable->klass->name);
216 runtime_invoke (o, NULL, &exc, NULL);
219 mono_internal_thread_unhandled_exception (exc);
221 mono_domain_set_internal (caller_domain);
225 mono_gc_finalize_threadpool_threads (void)
227 while (threads_to_finalize) {
228 MonoInternalThread *thread = (MonoInternalThread*) mono_mlist_get_data (threads_to_finalize);
230 /* Force finalization of the thread. */
231 thread->threadpool_thread = FALSE;
232 mono_object_register_finalizer ((MonoObject*)thread);
234 mono_gc_run_finalize (thread, NULL);
236 threads_to_finalize = mono_mlist_next (threads_to_finalize);
241 mono_gc_out_of_memory (size_t size)
244 * we could allocate at program startup some memory that we could release
245 * back to the system at this point if we're really low on memory (ie, size is
246 * lower than the memory we set apart)
248 mono_raise_exception (mono_domain_get ()->out_of_memory_ex);
254 * Some of our objects may point to a different address than the address returned by GC_malloc()
255 * (because of the GetHashCode hack), but we need to pass the real address to register_finalizer.
256 * This also means that in the callback we need to adjust the pointer to get back the real
258 * We also need to be consistent in the use of the GC_debug* variants of malloc and register_finalizer,
259 * since that, too, can cause the underlying pointer to be offset.
262 object_register_finalizer (MonoObject *obj, void (*callback)(void *, void*))
269 mono_raise_exception (mono_get_exception_argument_null ("obj"));
271 domain = obj->vtable->domain;
274 /* This assertion is not valid when GC_DEBUG is defined */
275 g_assert (GC_base (obj) == (char*)obj - offset);
278 if (mono_domain_is_unloading (domain) && (callback != NULL))
280 * Can't register finalizers in a dying appdomain, since they
281 * could be invoked after the appdomain has been unloaded.
285 mono_domain_finalizers_lock (domain);
288 g_hash_table_insert (domain->finalizable_objects_hash, obj, obj);
290 g_hash_table_remove (domain->finalizable_objects_hash, obj);
292 mono_domain_finalizers_unlock (domain);
294 GC_REGISTER_FINALIZER_NO_ORDER ((char*)obj - offset, callback, GUINT_TO_POINTER (offset), NULL, NULL);
295 #elif defined(HAVE_SGEN_GC)
297 mono_raise_exception (mono_get_exception_argument_null ("obj"));
300 * If we register finalizers for domains that are unloading we might
301 * end up running them while or after the domain is being cleared, so
302 * the objects will not be valid anymore.
304 if (!mono_domain_is_unloading (obj->vtable->domain))
305 mono_gc_register_for_finalization (obj, callback);
310 * mono_object_register_finalizer:
311 * @obj: object to register
313 * Records that object @obj has a finalizer, this will call the
314 * Finalize method when the garbage collector disposes the object.
318 mono_object_register_finalizer (MonoObject *obj)
320 /* g_print ("Registered finalizer on %p %s.%s\n", obj, mono_object_class (obj)->name_space, mono_object_class (obj)->name); */
321 object_register_finalizer (obj, mono_gc_run_finalize);
325 * mono_domain_finalize:
326 * @domain: the domain to finalize
327 * @timeout: msects to wait for the finalization to complete, -1 to wait indefinitely
329 * Request finalization of all finalizable objects inside @domain. Wait
330 * @timeout msecs for the finalization to complete.
332 * Returns: TRUE if succeeded, FALSE if there was a timeout
336 mono_domain_finalize (MonoDomain *domain, guint32 timeout)
338 DomainFinalizationReq *req;
341 MonoInternalThread *thread = mono_thread_internal_current ();
343 if (mono_thread_internal_current () == gc_thread)
344 /* We are called from inside a finalizer, not much we can do here */
348 * No need to create another thread 'cause the finalizer thread
349 * is still working and will take care of running the finalizers
356 mono_gc_collect (mono_gc_max_generation ());
358 done_event = CreateEvent (NULL, TRUE, FALSE, NULL);
359 if (done_event == NULL) {
363 req = g_new0 (DomainFinalizationReq, 1);
364 req->domain = domain;
365 req->done_event = done_event;
367 if (domain == mono_get_root_domain ())
368 finalizing_root_domain = TRUE;
370 mono_finalizer_lock ();
372 domains_to_finalize = g_slist_append (domains_to_finalize, req);
374 mono_finalizer_unlock ();
376 /* Tell the finalizer thread to finalize this appdomain */
377 mono_gc_finalize_notify ();
383 res = WaitForSingleObjectEx (done_event, timeout, TRUE);
384 /* printf ("WAIT RES: %d.\n", res); */
386 if (res == WAIT_IO_COMPLETION) {
387 if ((thread->state & (ThreadState_StopRequested | ThreadState_SuspendRequested)) != 0)
389 } else if (res == WAIT_TIMEOUT) {
390 /* We leak the handle here */
397 CloseHandle (done_event);
399 if (domain == mono_get_root_domain ()) {
400 mono_thread_pool_cleanup ();
401 mono_gc_finalize_threadpool_threads ();
406 /* We don't support domain finalization without a GC */
412 ves_icall_System_GC_InternalCollect (int generation)
414 mono_gc_collect (generation);
418 ves_icall_System_GC_GetTotalMemory (MonoBoolean forceCollection)
423 mono_gc_collect (mono_gc_max_generation ());
424 return mono_gc_get_used_size ();
428 ves_icall_System_GC_KeepAlive (MonoObject *obj)
438 ves_icall_System_GC_ReRegisterForFinalize (MonoObject *obj)
441 mono_raise_exception (mono_get_exception_argument_null ("obj"));
443 object_register_finalizer (obj, mono_gc_run_finalize);
447 ves_icall_System_GC_SuppressFinalize (MonoObject *obj)
450 mono_raise_exception (mono_get_exception_argument_null ("obj"));
452 /* delegates have no finalizers, but we register them to deal with the
453 * unmanaged->managed trampoline. We don't let the user suppress it
454 * otherwise we'd leak it.
456 if (obj->vtable->klass->delegate)
459 /* FIXME: Need to handle case where obj has COM Callable Wrapper
460 * generated for it that needs cleaned up, but user wants to suppress
461 * their derived object finalizer. */
463 object_register_finalizer (obj, NULL);
467 ves_icall_System_GC_WaitForPendingFinalizers (void)
470 if (!mono_gc_pending_finalizers ())
473 if (mono_thread_internal_current () == gc_thread)
474 /* Avoid deadlocks */
478 If the finalizer thread is not live, lets pretend no finalizers are pending since the current thread might
479 be the one responsible for starting it up.
481 if (gc_thread == NULL)
484 ResetEvent (pending_done_event);
485 mono_gc_finalize_notify ();
486 /* g_print ("Waiting for pending finalizers....\n"); */
487 WaitForSingleObjectEx (pending_done_event, INFINITE, TRUE);
488 /* g_print ("Done pending....\n"); */
493 ves_icall_System_GC_register_ephemeron_array (MonoObject *array)
496 if (!mono_gc_ephemeron_array_add (array))
497 mono_raise_exception (mono_object_domain (array)->out_of_memory_ex);
502 ves_icall_System_GC_get_ephemeron_tombstone (void)
504 return mono_domain_get ()->ephemeron_tombstone;
507 #define mono_allocator_lock() EnterCriticalSection (&allocator_section)
508 #define mono_allocator_unlock() LeaveCriticalSection (&allocator_section)
509 static CRITICAL_SECTION allocator_section;
510 static CRITICAL_SECTION handle_section;
519 static HandleType mono_gchandle_get_type (guint32 gchandle);
522 ves_icall_System_GCHandle_GetTarget (guint32 handle)
524 return mono_gchandle_get_target (handle);
528 * if type == -1, change the target of the handle, otherwise allocate a new handle.
531 ves_icall_System_GCHandle_GetTargetHandle (MonoObject *obj, guint32 handle, gint32 type)
534 mono_gchandle_set_target (handle, obj);
535 /* the handle doesn't change */
540 return mono_gchandle_new_weakref (obj, FALSE);
541 case HANDLE_WEAK_TRACK:
542 return mono_gchandle_new_weakref (obj, TRUE);
544 return mono_gchandle_new (obj, FALSE);
546 return mono_gchandle_new (obj, TRUE);
548 g_assert_not_reached ();
554 ves_icall_System_GCHandle_FreeHandle (guint32 handle)
556 mono_gchandle_free (handle);
560 ves_icall_System_GCHandle_GetAddrOfPinnedObject (guint32 handle)
564 if (mono_gchandle_get_type (handle) != HANDLE_PINNED)
566 obj = mono_gchandle_get_target (handle);
568 MonoClass *klass = mono_object_class (obj);
569 if (klass == mono_defaults.string_class) {
570 return mono_string_chars ((MonoString*)obj);
571 } else if (klass->rank) {
572 return mono_array_addr ((MonoArray*)obj, char, 0);
574 /* the C# code will check and throw the exception */
575 /* FIXME: missing !klass->blittable test, see bug #61134 */
576 if ((klass->flags & TYPE_ATTRIBUTE_LAYOUT_MASK) == TYPE_ATTRIBUTE_AUTO_LAYOUT)
578 return (char*)obj + sizeof (MonoObject);
589 guint slot_hint : 24; /* starting slot for search */
590 /* 2^16 appdomains should be enough for everyone (though I know I'll regret this in 20 years) */
591 /* we alloc this only for weak refs, since we can get the domain directly in the other cases */
595 /* weak and weak-track arrays will be allocated in malloc memory
597 static HandleData gc_handles [] = {
598 {NULL, NULL, 0, HANDLE_WEAK, 0},
599 {NULL, NULL, 0, HANDLE_WEAK_TRACK, 0},
600 {NULL, NULL, 0, HANDLE_NORMAL, 0},
601 {NULL, NULL, 0, HANDLE_PINNED, 0}
604 #define lock_handles(handles) EnterCriticalSection (&handle_section)
605 #define unlock_handles(handles) LeaveCriticalSection (&handle_section)
608 find_first_unset (guint32 bitmap)
611 for (i = 0; i < 32; ++i) {
612 if (!(bitmap & (1 << i)))
619 make_root_descr_all_refs (int numbits, gboolean pinned)
625 return mono_gc_make_root_descr_all_refs (numbits);
629 alloc_handle (HandleData *handles, MonoObject *obj, gboolean track)
633 lock_handles (handles);
634 if (!handles->size) {
636 if (handles->type > HANDLE_WEAK_TRACK) {
637 handles->entries = mono_gc_alloc_fixed (sizeof (gpointer) * handles->size, make_root_descr_all_refs (handles->size, handles->type == HANDLE_PINNED));
639 handles->entries = g_malloc0 (sizeof (gpointer) * handles->size);
640 handles->domain_ids = g_malloc0 (sizeof (guint16) * handles->size);
642 handles->bitmap = g_malloc0 (handles->size / 8);
645 for (slot = handles->slot_hint; slot < handles->size / 32; ++slot) {
646 if (handles->bitmap [slot] != 0xffffffff) {
647 i = find_first_unset (handles->bitmap [slot]);
648 handles->slot_hint = slot;
652 if (i == -1 && handles->slot_hint != 0) {
653 for (slot = 0; slot < handles->slot_hint; ++slot) {
654 if (handles->bitmap [slot] != 0xffffffff) {
655 i = find_first_unset (handles->bitmap [slot]);
656 handles->slot_hint = slot;
663 guint32 new_size = handles->size * 2; /* always double: we memset to 0 based on this below */
665 /* resize and copy the bitmap */
666 new_bitmap = g_malloc0 (new_size / 8);
667 memcpy (new_bitmap, handles->bitmap, handles->size / 8);
668 g_free (handles->bitmap);
669 handles->bitmap = new_bitmap;
671 /* resize and copy the entries */
672 if (handles->type > HANDLE_WEAK_TRACK) {
675 entries = mono_gc_alloc_fixed (sizeof (gpointer) * new_size, make_root_descr_all_refs (new_size, handles->type == HANDLE_PINNED));
676 mono_gc_memmove (entries, handles->entries, sizeof (gpointer) * handles->size);
678 mono_gc_free_fixed (handles->entries);
679 handles->entries = entries;
683 domain_ids = g_malloc0 (sizeof (guint16) * new_size);
684 entries = g_malloc0 (sizeof (gpointer) * new_size);
685 memcpy (domain_ids, handles->domain_ids, sizeof (guint16) * handles->size);
686 for (i = 0; i < handles->size; ++i) {
687 MonoObject *obj = mono_gc_weak_link_get (&(handles->entries [i]));
689 mono_gc_weak_link_add (&(entries [i]), obj, track);
690 mono_gc_weak_link_remove (&(handles->entries [i]), track);
692 g_assert (!handles->entries [i]);
695 g_free (handles->entries);
696 g_free (handles->domain_ids);
697 handles->entries = entries;
698 handles->domain_ids = domain_ids;
701 /* set i and slot to the next free position */
703 slot = (handles->size + 1) / 32;
704 handles->slot_hint = handles->size + 1;
705 handles->size = new_size;
707 handles->bitmap [slot] |= 1 << i;
708 slot = slot * 32 + i;
709 handles->entries [slot] = NULL;
710 if (handles->type <= HANDLE_WEAK_TRACK) {
711 /*FIXME, what to use when obj == null?*/
712 handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
714 mono_gc_weak_link_add (&(handles->entries [slot]), obj, track);
716 handles->entries [slot] = obj;
719 #ifndef DISABLE_PERFCOUNTERS
720 mono_perfcounters->gc_num_handles++;
722 unlock_handles (handles);
723 /*g_print ("allocated entry %d of type %d to object %p (in slot: %p)\n", slot, handles->type, obj, handles->entries [slot]);*/
724 res = (slot << 3) | (handles->type + 1);
725 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_CREATED, handles->type, res, obj);
731 * @obj: managed object to get a handle for
732 * @pinned: whether the object should be pinned
734 * This returns a handle that wraps the object, this is used to keep a
735 * reference to a managed object from the unmanaged world and preventing the
736 * object from being disposed.
738 * If @pinned is false the address of the object can not be obtained, if it is
739 * true the address of the object can be obtained. This will also pin the
740 * object so it will not be possible by a moving garbage collector to move the
743 * Returns: a handle that can be used to access the object from
747 mono_gchandle_new (MonoObject *obj, gboolean pinned)
749 return alloc_handle (&gc_handles [pinned? HANDLE_PINNED: HANDLE_NORMAL], obj, FALSE);
753 * mono_gchandle_new_weakref:
754 * @obj: managed object to get a handle for
755 * @pinned: whether the object should be pinned
757 * This returns a weak handle that wraps the object, this is used to
758 * keep a reference to a managed object from the unmanaged world.
759 * Unlike the mono_gchandle_new the object can be reclaimed by the
760 * garbage collector. In this case the value of the GCHandle will be
763 * If @pinned is false the address of the object can not be obtained, if it is
764 * true the address of the object can be obtained. This will also pin the
765 * object so it will not be possible by a moving garbage collector to move the
768 * Returns: a handle that can be used to access the object from
772 mono_gchandle_new_weakref (MonoObject *obj, gboolean track_resurrection)
774 guint32 handle = alloc_handle (&gc_handles [track_resurrection? HANDLE_WEAK_TRACK: HANDLE_WEAK], obj, track_resurrection);
780 mono_gchandle_get_type (guint32 gchandle)
782 guint type = (gchandle & 7) - 1;
788 * mono_gchandle_get_target:
789 * @gchandle: a GCHandle's handle.
791 * The handle was previously created by calling mono_gchandle_new or
792 * mono_gchandle_new_weakref.
794 * Returns a pointer to the MonoObject represented by the handle or
795 * NULL for a collected object if using a weakref handle.
798 mono_gchandle_get_target (guint32 gchandle)
800 guint slot = gchandle >> 3;
801 guint type = (gchandle & 7) - 1;
802 HandleData *handles = &gc_handles [type];
803 MonoObject *obj = NULL;
806 lock_handles (handles);
807 if (slot < handles->size && (handles->bitmap [slot / 32] & (1 << (slot % 32)))) {
808 if (handles->type <= HANDLE_WEAK_TRACK) {
809 obj = mono_gc_weak_link_get (&handles->entries [slot]);
811 obj = handles->entries [slot];
814 /* print a warning? */
816 unlock_handles (handles);
817 /*g_print ("get target of entry %d of type %d: %p\n", slot, handles->type, obj);*/
822 mono_gchandle_set_target (guint32 gchandle, MonoObject *obj)
824 guint slot = gchandle >> 3;
825 guint type = (gchandle & 7) - 1;
826 HandleData *handles = &gc_handles [type];
827 MonoObject *old_obj = NULL;
831 lock_handles (handles);
832 if (slot < handles->size && (handles->bitmap [slot / 32] & (1 << (slot % 32)))) {
833 if (handles->type <= HANDLE_WEAK_TRACK) {
834 old_obj = handles->entries [slot];
835 if (handles->entries [slot])
836 mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
838 mono_gc_weak_link_add (&handles->entries [slot], obj, handles->type == HANDLE_WEAK_TRACK);
839 /*FIXME, what to use when obj == null?*/
840 handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
842 handles->entries [slot] = obj;
845 /* print a warning? */
847 /*g_print ("changed entry %d of type %d to object %p (in slot: %p)\n", slot, handles->type, obj, handles->entries [slot]);*/
848 unlock_handles (handles);
852 * mono_gchandle_is_in_domain:
853 * @gchandle: a GCHandle's handle.
854 * @domain: An application domain.
856 * Returns: true if the object wrapped by the @gchandle belongs to the specific @domain.
859 mono_gchandle_is_in_domain (guint32 gchandle, MonoDomain *domain)
861 guint slot = gchandle >> 3;
862 guint type = (gchandle & 7) - 1;
863 HandleData *handles = &gc_handles [type];
864 gboolean result = FALSE;
867 lock_handles (handles);
868 if (slot < handles->size && (handles->bitmap [slot / 32] & (1 << (slot % 32)))) {
869 if (handles->type <= HANDLE_WEAK_TRACK) {
870 result = domain->domain_id == handles->domain_ids [slot];
873 obj = handles->entries [slot];
877 result = domain == mono_object_domain (obj);
880 /* print a warning? */
882 unlock_handles (handles);
887 * mono_gchandle_free:
888 * @gchandle: a GCHandle's handle.
890 * Frees the @gchandle handle. If there are no outstanding
891 * references, the garbage collector can reclaim the memory of the
895 mono_gchandle_free (guint32 gchandle)
897 guint slot = gchandle >> 3;
898 guint type = (gchandle & 7) - 1;
899 HandleData *handles = &gc_handles [type];
903 lock_handles (handles);
904 if (slot < handles->size && (handles->bitmap [slot / 32] & (1 << (slot % 32)))) {
905 if (handles->type <= HANDLE_WEAK_TRACK) {
906 if (handles->entries [slot])
907 mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
909 handles->entries [slot] = NULL;
911 handles->bitmap [slot / 32] &= ~(1 << (slot % 32));
913 /* print a warning? */
915 #ifndef DISABLE_PERFCOUNTERS
916 mono_perfcounters->gc_num_handles--;
918 /*g_print ("freed entry %d of type %d\n", slot, handles->type);*/
919 unlock_handles (handles);
920 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_DESTROYED, handles->type, gchandle, NULL);
924 * mono_gchandle_free_domain:
925 * @domain: domain that is unloading
927 * Function used internally to cleanup any GC handle for objects belonging
928 * to the specified domain during appdomain unload.
931 mono_gchandle_free_domain (MonoDomain *domain)
935 for (type = 0; type < 3; ++type) {
937 HandleData *handles = &gc_handles [type];
938 lock_handles (handles);
939 for (slot = 0; slot < handles->size; ++slot) {
940 if (!(handles->bitmap [slot / 32] & (1 << (slot % 32))))
942 if (type <= HANDLE_WEAK_TRACK) {
943 if (domain->domain_id == handles->domain_ids [slot]) {
944 handles->bitmap [slot / 32] &= ~(1 << (slot % 32));
945 if (handles->entries [slot])
946 mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
949 if (handles->entries [slot] && mono_object_domain (handles->entries [slot]) == domain) {
950 handles->bitmap [slot / 32] &= ~(1 << (slot % 32));
951 handles->entries [slot] = NULL;
955 unlock_handles (handles);
961 GCHandle_CheckCurrentDomain (guint32 gchandle)
963 return mono_gchandle_is_in_domain (gchandle, mono_domain_get ());
968 #ifdef MONO_HAS_SEMAPHORES
969 static MonoSemType finalizer_sem;
971 static HANDLE finalizer_event;
972 static volatile gboolean finished=FALSE;
975 mono_gc_finalize_notify (void)
978 g_message ( "%s: prodding finalizer", __func__);
981 #ifdef MONO_HAS_SEMAPHORES
982 MONO_SEM_POST (&finalizer_sem);
984 SetEvent (finalizer_event);
991 collect_objects (gpointer key, gpointer value, gpointer user_data)
993 GPtrArray *arr = (GPtrArray*)user_data;
994 g_ptr_array_add (arr, key);
1000 * finalize_domain_objects:
1002 * Run the finalizers of all finalizable objects in req->domain.
1005 finalize_domain_objects (DomainFinalizationReq *req)
1007 MonoDomain *domain = req->domain;
1010 #define NUM_FOBJECTS 64
1011 MonoObject *to_finalize [NUM_FOBJECTS];
1015 /* Process finalizers which are already in the queue */
1016 mono_gc_invoke_finalizers ();
1018 #ifdef HAVE_BOEHM_GC
1019 while (g_hash_table_size (domain->finalizable_objects_hash) > 0) {
1023 * Since the domain is unloading, nobody is allowed to put
1024 * new entries into the hash table. But finalize_object might
1025 * remove entries from the hash table, so we make a copy.
1027 objs = g_ptr_array_new ();
1028 g_hash_table_foreach (domain->finalizable_objects_hash, collect_objects, objs);
1029 /* printf ("FINALIZING %d OBJECTS.\n", objs->len); */
1031 for (i = 0; i < objs->len; ++i) {
1032 MonoObject *o = (MonoObject*)g_ptr_array_index (objs, i);
1033 /* FIXME: Avoid finalizing threads, etc */
1034 mono_gc_run_finalize (o, 0);
1037 g_ptr_array_free (objs, TRUE);
1039 #elif defined(HAVE_SGEN_GC)
1040 while ((count = mono_gc_finalizers_for_domain (domain, to_finalize, NUM_FOBJECTS))) {
1042 for (i = 0; i < count; ++i) {
1043 mono_gc_run_finalize (to_finalize [i], 0);
1048 /* cleanup the reference queue */
1049 reference_queue_clear_for_domain (domain);
1051 /* printf ("DONE.\n"); */
1052 SetEvent (req->done_event);
1054 /* The event is closed in mono_domain_finalize if we get here */
1059 finalizer_thread (gpointer unused)
1062 /* Wait to be notified that there's at least one
1066 g_assert (mono_domain_get () == mono_get_root_domain ());
1068 /* An alertable wait is required so this thread can be suspended on windows */
1069 #ifdef MONO_HAS_SEMAPHORES
1070 MONO_SEM_WAIT_ALERTABLE (&finalizer_sem, TRUE);
1072 WaitForSingleObjectEx (finalizer_event, INFINITE, TRUE);
1075 mono_threads_perform_thread_dump ();
1077 mono_console_handle_async_ops ();
1079 #ifndef DISABLE_ATTACH
1080 mono_attach_maybe_start ();
1083 if (domains_to_finalize) {
1084 mono_finalizer_lock ();
1085 if (domains_to_finalize) {
1086 DomainFinalizationReq *req = domains_to_finalize->data;
1087 domains_to_finalize = g_slist_remove (domains_to_finalize, req);
1088 mono_finalizer_unlock ();
1090 finalize_domain_objects (req);
1092 mono_finalizer_unlock ();
1096 /* If finished == TRUE, mono_gc_cleanup has been called (from mono_runtime_cleanup),
1097 * before the domain is unloaded.
1099 mono_gc_invoke_finalizers ();
1101 reference_queue_proccess_all ();
1103 SetEvent (pending_done_event);
1106 SetEvent (shutdown_event);
1110 #ifndef LAZY_GC_THREAD_CREATION
1114 mono_gc_init_finalizer_thread (void)
1116 gc_thread = mono_thread_create_internal (mono_domain_get (), finalizer_thread, NULL, FALSE, TRUE, 0);
1117 ves_icall_System_Threading_Thread_SetName_internal (gc_thread, mono_string_new (mono_domain_get (), "Finalizer"));
1123 InitializeCriticalSection (&handle_section);
1124 InitializeCriticalSection (&allocator_section);
1126 InitializeCriticalSection (&finalizer_mutex);
1127 InitializeCriticalSection (&reference_queue_mutex);
1129 MONO_GC_REGISTER_ROOT_FIXED (gc_handles [HANDLE_NORMAL].entries);
1130 MONO_GC_REGISTER_ROOT_FIXED (gc_handles [HANDLE_PINNED].entries);
1132 mono_counters_register ("Minor GC collections", MONO_COUNTER_GC | MONO_COUNTER_INT, &gc_stats.minor_gc_count);
1133 mono_counters_register ("Major GC collections", MONO_COUNTER_GC | MONO_COUNTER_INT, &gc_stats.major_gc_count);
1134 mono_counters_register ("Minor GC time", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &gc_stats.minor_gc_time_usecs);
1135 mono_counters_register ("Major GC time", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &gc_stats.major_gc_time_usecs);
1137 mono_gc_base_init ();
1139 if (mono_gc_is_disabled ()) {
1144 finalizer_event = CreateEvent (NULL, FALSE, FALSE, NULL);
1145 pending_done_event = CreateEvent (NULL, TRUE, FALSE, NULL);
1146 shutdown_event = CreateEvent (NULL, TRUE, FALSE, NULL);
1147 if (finalizer_event == NULL || pending_done_event == NULL || shutdown_event == NULL) {
1148 g_assert_not_reached ();
1150 #ifdef MONO_HAS_SEMAPHORES
1151 MONO_SEM_INIT (&finalizer_sem, 0);
1154 #ifndef LAZY_GC_THREAD_CREATION
1155 mono_gc_init_finalizer_thread ();
1160 mono_gc_cleanup (void)
1163 g_message ("%s: cleaning up finalizer", __func__);
1167 ResetEvent (shutdown_event);
1169 if (mono_thread_internal_current () != gc_thread) {
1170 mono_gc_finalize_notify ();
1171 /* Finishing the finalizer thread, so wait a little bit... */
1172 /* MS seems to wait for about 2 seconds */
1173 if (WaitForSingleObjectEx (shutdown_event, 2000, FALSE) == WAIT_TIMEOUT) {
1176 /* Set a flag which the finalizer thread can check */
1177 suspend_finalizers = TRUE;
1179 /* Try to abort the thread, in the hope that it is running managed code */
1180 mono_thread_internal_stop (gc_thread);
1182 /* Wait for it to stop */
1183 ret = WaitForSingleObjectEx (gc_thread->handle, 100, TRUE);
1185 if (ret == WAIT_TIMEOUT) {
1187 * The finalizer thread refused to die. There is not much we
1188 * can do here, since the runtime is shutting down so the
1189 * state the finalizer thread depends on will vanish.
1191 g_warning ("Shutting down finalizer thread timed out.");
1194 * FIXME: On unix, when the above wait returns, the thread
1195 * might still be running io-layer code, or pthreads code.
1202 /* Wait for the thread to actually exit */
1203 ret = WaitForSingleObjectEx (gc_thread->handle, INFINITE, TRUE);
1204 g_assert (ret == WAIT_OBJECT_0);
1208 * The above wait only waits for the exited event to be signalled, the thread might still be running. To fix this race, we
1209 * create the finalizer thread without calling pthread_detach () on it, so we can wait for it manually.
1211 ret = pthread_join ((gpointer)(gsize)gc_thread->tid, NULL);
1212 g_assert (ret == 0);
1217 #ifdef HAVE_BOEHM_GC
1218 GC_finalizer_notifier = NULL;
1222 mono_reference_queue_cleanup ();
1224 DeleteCriticalSection (&handle_section);
1225 DeleteCriticalSection (&allocator_section);
1226 DeleteCriticalSection (&finalizer_mutex);
1227 DeleteCriticalSection (&reference_queue_mutex);
1232 /* Null GC dummy functions */
1234 mono_gc_finalize_notify (void)
1238 void mono_gc_init (void)
1240 InitializeCriticalSection (&handle_section);
1243 void mono_gc_cleanup (void)
1250 mono_gc_is_finalizer_internal_thread (MonoInternalThread *thread)
1252 return thread == gc_thread;
1256 * mono_gc_is_finalizer_thread:
1257 * @thread: the thread to test.
1259 * In Mono objects are finalized asynchronously on a separate thread.
1260 * This routine tests whether the @thread argument represents the
1261 * finalization thread.
1263 * Returns true if @thread is the finalization thread.
1266 mono_gc_is_finalizer_thread (MonoThread *thread)
1268 return mono_gc_is_finalizer_internal_thread (thread->internal_thread);
1271 #if defined(__MACH__)
1272 static pthread_t mach_exception_thread;
1275 mono_gc_register_mach_exception_thread (pthread_t thread)
1277 mach_exception_thread = thread;
1281 mono_gc_get_mach_exception_thread (void)
1283 return mach_exception_thread;
1288 * mono_gc_parse_environment_string_extract_number:
1290 * @str: points to the first digit of the number
1291 * @out: pointer to the variable that will receive the value
1293 * Tries to extract a number from the passed string, taking in to account m, k
1296 * Returns true if passing was successful
1299 mono_gc_parse_environment_string_extract_number (const char *str, glong *out)
1302 int len = strlen (str), shift = 0;
1304 gboolean is_suffix = FALSE;
1310 suffix = str [len - 1];
1325 if (!isdigit (suffix))
1331 val = strtol (str, &endptr, 10);
1333 if ((errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
1334 || (errno != 0 && val == 0) || (endptr == str))
1340 if (val < 0) /* negative numbers cannot be suffixed */
1342 if (*(endptr + 1)) /* Invalid string. */
1345 unshifted = (gulong)val;
1347 if (val < 0) /* overflow */
1349 if (((gulong)val >> shift) != unshifted) /* value too large */
1357 #ifndef HAVE_SGEN_GC
1359 mono_gc_alloc_mature (MonoVTable *vtable)
1361 return mono_object_new_specific (vtable);
1366 static MonoReferenceQueue *ref_queues;
1369 ref_list_remove_element (RefQueueEntry **prev, RefQueueEntry *element)
1372 /* Guard if head is changed concurrently. */
1373 while (*prev != element)
1374 prev = &(*prev)->next;
1375 } while (prev && InterlockedCompareExchangePointer ((void*)prev, element->next, element) != element);
1379 ref_list_push (RefQueueEntry **head, RefQueueEntry *value)
1381 RefQueueEntry *current;
1384 value->next = current;
1385 STORE_STORE_FENCE; /*Must make sure the previous store is visible before the CAS. */
1386 } while (InterlockedCompareExchangePointer ((void*)head, value, current) != current);
1390 reference_queue_proccess (MonoReferenceQueue *queue)
1392 RefQueueEntry **iter = &queue->queue;
1393 RefQueueEntry *entry;
1394 while ((entry = *iter)) {
1396 if (queue->should_be_deleted || !mono_gc_weak_link_get (&entry->dis_link)) {
1397 mono_gc_weak_link_remove (&entry->dis_link, TRUE);
1399 if (queue->should_be_deleted || !mono_gchandle_get_target (entry->gchandle)) {
1400 mono_gchandle_free ((guint32)entry->gchandle);
1402 ref_list_remove_element (iter, entry);
1403 queue->callback (entry->user_data);
1406 iter = &entry->next;
1412 reference_queue_proccess_all (void)
1414 MonoReferenceQueue **iter;
1415 MonoReferenceQueue *queue = ref_queues;
1416 for (; queue; queue = queue->next)
1417 reference_queue_proccess (queue);
1420 EnterCriticalSection (&reference_queue_mutex);
1421 for (iter = &ref_queues; *iter;) {
1423 if (!queue->should_be_deleted) {
1424 iter = &queue->next;
1428 LeaveCriticalSection (&reference_queue_mutex);
1429 reference_queue_proccess (queue);
1432 *iter = queue->next;
1435 LeaveCriticalSection (&reference_queue_mutex);
1439 mono_reference_queue_cleanup (void)
1441 MonoReferenceQueue *queue = ref_queues;
1442 for (; queue; queue = queue->next)
1443 queue->should_be_deleted = TRUE;
1444 reference_queue_proccess_all ();
1448 reference_queue_clear_for_domain (MonoDomain *domain)
1450 MonoReferenceQueue *queue = ref_queues;
1451 for (; queue; queue = queue->next) {
1452 RefQueueEntry **iter = &queue->queue;
1453 RefQueueEntry *entry;
1454 while ((entry = *iter)) {
1457 obj = mono_gc_weak_link_get (&entry->dis_link);
1458 if (obj && mono_object_domain (obj) == domain) {
1459 mono_gc_weak_link_remove (&entry->dis_link, TRUE);
1461 obj = mono_gchandle_get_target (entry->gchandle);
1462 if (obj && mono_object_domain (obj) == domain) {
1463 mono_gchandle_free ((guint32)entry->gchandle);
1465 ref_list_remove_element (iter, entry);
1466 queue->callback (entry->user_data);
1469 iter = &entry->next;
1475 * mono_gc_reference_queue_new:
1476 * @callback callback used when processing dead entries.
1478 * Create a new reference queue used to process collected objects.
1479 * A reference queue let you queue a pair (managed object, user data)
1480 * using the mono_gc_reference_queue_add method.
1482 * Once the managed object is collected @callback will be called
1483 * in the finalizer thread with 'user data' as argument.
1485 * The callback is called without any locks held.
1488 mono_gc_reference_queue_new (mono_reference_queue_callback callback)
1490 MonoReferenceQueue *res = g_new0 (MonoReferenceQueue, 1);
1491 res->callback = callback;
1493 EnterCriticalSection (&reference_queue_mutex);
1494 res->next = ref_queues;
1496 LeaveCriticalSection (&reference_queue_mutex);
1502 * mono_gc_reference_queue_add:
1503 * @queue the queue to add the reference to.
1504 * @obj the object to be watched for collection
1505 * @user_data parameter to be passed to the queue callback
1507 * Queue an object to be watched for collection, when the @obj is
1508 * collected, the callback that was registered for the @queue will
1509 * be invoked with the @obj and @user_data arguments.
1511 * @returns false if the queue is scheduled to be freed.
1514 mono_gc_reference_queue_add (MonoReferenceQueue *queue, MonoObject *obj, void *user_data)
1516 RefQueueEntry *entry;
1517 if (queue->should_be_deleted)
1520 entry = g_new0 (RefQueueEntry, 1);
1521 entry->user_data = user_data;
1524 mono_gc_weak_link_add (&entry->dis_link, obj, TRUE);
1526 entry->gchandle = mono_gchandle_new_weakref (obj, TRUE);
1527 mono_object_register_finalizer (obj);
1530 ref_list_push (&queue->queue, entry);
1535 * mono_gc_reference_queue_free:
1536 * @queue the queue that should be deleted.
1538 * This operation signals that @queue should be deleted. This operation is deferred
1539 * as it happens on the finalizer thread.
1541 * After this call, no further objects can be queued. It's the responsibility of the
1542 * caller to make sure that no further attempt to access queue will be made.
1545 mono_gc_reference_queue_free (MonoReferenceQueue *queue)
1547 queue->should_be_deleted = TRUE;
1550 #define ptr_mask ((sizeof (void*) - 1))
1551 #define _toi(ptr) ((size_t)ptr)
1552 #define unaligned_bytes(ptr) (_toi(ptr) & ptr_mask)
1553 #define align_down(ptr) ((void*)(_toi(ptr) & ~ptr_mask))
1554 #define align_up(ptr) ((void*) ((_toi(ptr) + ptr_mask) & ~ptr_mask))
1558 * @dest: address to start to clear
1559 * @size: size of the region to clear
1561 * Zero @size bytes starting at @dest.
1563 * Use this to zero memory that can hold managed pointers.
1565 * FIXME borrow faster code from some BSD libc or bionic
1568 mono_gc_bzero (void *dest, size_t size)
1570 char *p = (char*)dest;
1571 char *end = p + size;
1572 char *align_end = align_up (p);
1575 while (p < align_end)
1578 word_end = align_down (end);
1579 while (p < word_end) {
1580 *((void**)p) = NULL;
1581 p += sizeof (void*);
1591 * @dest: destination of the move
1593 * @size: size of the block to move
1595 * Move @size bytes from @src to @dest.
1596 * size MUST be a multiple of sizeof (gpointer)
1598 * FIXME borrow faster code from some BSD libc or bionic
1601 mono_gc_memmove (void *dest, const void *src, size_t size)
1604 * If dest and src are differently aligned with respect to
1605 * pointer size then it makes no sense to do aligned copying.
1606 * In fact, we would end up with unaligned loads which is
1607 * incorrect on some architectures.
1609 if ((char*)dest - (char*)align_down (dest) != (char*)src - (char*)align_down (src)) {
1610 memmove (dest, src, size);
1615 * A bit of explanation on why we align only dest before doing word copies.
1616 * Pointers to managed objects must always be stored in word aligned addresses, so
1617 * even if dest is misaligned, src will be by the same amount - this ensure proper atomicity of reads.
1619 if (dest > src && ((size_t)((char*)dest - (char*)src) < size)) {
1620 char *p = (char*)dest + size;
1621 char *s = (char*)src + size;
1622 char *start = (char*)dest;
1623 char *align_end = MAX((char*)dest, (char*)align_down (p));
1626 while (p > align_end)
1629 word_start = align_up (start);
1630 while (p > word_start) {
1631 p -= sizeof (void*);
1632 s -= sizeof (void*);
1633 *((void**)p) = *((void**)s);
1639 char *p = (char*)dest;
1640 char *s = (char*)src;
1641 char *end = p + size;
1642 char *align_end = MIN ((char*)end, (char*)align_up (p));
1645 while (p < align_end)
1648 word_end = align_down (end);
1649 while (p < word_end) {
1650 *((void**)p) = *((void**)s);
1651 p += sizeof (void*);
1652 s += sizeof (void*);