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-internal.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-internal.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-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;
65 mono_gc_warning (char *msg, GC_word arg)
67 mono_trace (G_LOG_LEVEL_WARNING, MONO_TRACE_GC, msg, (unsigned long)arg);
71 mono_gc_base_init (void)
73 MonoThreadInfoCallbacks cb;
80 mono_counters_init ();
83 * Handle the case when we are called from a thread different from the main thread,
85 * FIXME: Move this to libgc where it belongs.
87 * we used to do this only when running on valgrind,
88 * but it happens also in other setups.
90 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK) && !defined(__native_client__)
95 pthread_getattr_np (pthread_self (), &attr);
96 pthread_attr_getstack (&attr, &sstart, &size);
97 pthread_attr_destroy (&attr);
98 /*g_print ("stackbottom pth is: %p\n", (char*)sstart + size);*/
101 * The calculation above doesn't seem to work on ia64, also we need to set
102 * GC_register_stackbottom as well, but don't know how.
105 /* apparently with some linuxthreads implementations sstart can be NULL,
106 * fallback to the more imprecise method (bug# 78096).
109 GC_stackbottom = (char*)sstart + size;
112 gsize stack_bottom = (gsize)&dummy;
113 stack_bottom += 4095;
114 stack_bottom &= ~4095;
115 GC_stackbottom = (char*)stack_bottom;
119 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
120 GC_stackbottom = (char*)pthread_get_stackaddr_np (pthread_self ());
121 #elif defined(__OpenBSD__)
122 # include <pthread_np.h>
127 rslt = pthread_stackseg_np(pthread_self(), &ss);
128 g_assert (rslt == 0);
130 GC_stackbottom = (char*)ss.ss_sp;
132 #elif defined(__native_client__)
133 /* Do nothing, GC_stackbottom is set correctly in libgc */
137 gsize stack_bottom = (gsize)&dummy;
138 stack_bottom += 4095;
139 stack_bottom &= ~4095;
140 /*g_print ("stackbottom is: %p\n", (char*)stack_bottom);*/
141 GC_stackbottom = (char*)stack_bottom;
145 #if !defined(PLATFORM_ANDROID)
146 /* If GC_no_dls is set to true, GC_find_limit is not called. This causes a seg fault on Android. */
150 if ((env = g_getenv ("MONO_GC_DEBUG"))) {
151 char **opts = g_strsplit (env, ",", -1);
152 for (char **ptr = opts; ptr && *ptr; ptr ++) {
154 if (!strcmp (opt, "do-not-finalize")) {
156 } else if (!strcmp (opt, "log-finalizers")) {
165 GC_oom_fn = mono_gc_out_of_memory;
166 GC_set_warn_proc (mono_gc_warning);
167 GC_finalize_on_demand = 1;
168 GC_finalizer_notifier = mono_gc_finalize_notify;
170 GC_init_gcj_malloc (5, NULL);
172 if ((env = g_getenv ("MONO_GC_PARAMS"))) {
173 char **ptr, **opts = g_strsplit (env, ",", -1);
174 for (ptr = opts; *ptr; ++ptr) {
176 if (g_str_has_prefix (opt, "max-heap-size=")) {
179 opt = strchr (opt, '=') + 1;
180 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
181 if (max_heap < MIN_BOEHM_MAX_HEAP_SIZE) {
182 fprintf (stderr, "max-heap-size must be at least %dMb.\n", MIN_BOEHM_MAX_HEAP_SIZE_IN_MB);
185 GC_set_max_heap_size (max_heap);
187 fprintf (stderr, "max-heap-size must be an integer.\n");
191 } else if (g_str_has_prefix (opt, "toggleref-test")) {
192 register_test_toggleref_callback ();
195 /* Could be a parameter for sgen */
197 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
198 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
206 memset (&cb, 0, sizeof (cb));
207 cb.thread_register = boehm_thread_register;
208 cb.thread_unregister = boehm_thread_unregister;
209 cb.mono_method_is_critical = (gpointer)mono_runtime_is_critical_method;
211 mono_threads_init (&cb, sizeof (MonoThreadInfo));
212 mono_mutex_init (&mono_gc_lock);
214 mono_thread_info_attach (&dummy);
216 mono_gc_enable_events ();
217 gc_initialized = TRUE;
222 * @generation: GC generation identifier
224 * Perform a garbage collection for the given generation, higher numbers
225 * mean usually older objects. Collecting a high-numbered generation
226 * implies collecting also the lower-numbered generations.
227 * The maximum value for @generation can be retrieved with a call to
228 * mono_gc_max_generation(), so this function is usually called as:
230 * mono_gc_collect (mono_gc_max_generation ());
233 mono_gc_collect (int generation)
235 #ifndef DISABLE_PERFCOUNTERS
236 mono_perfcounters->gc_induced++;
242 * mono_gc_max_generation:
244 * Get the maximum generation number used by the current garbage
245 * collector. The value will be 0 for the Boehm collector, 1 or more
246 * for the generational collectors.
248 * Returns: the maximum generation number.
251 mono_gc_max_generation (void)
257 * mono_gc_get_generation:
258 * @object: a managed object
260 * Get the garbage collector's generation that @object belongs to.
261 * Use this has a hint only.
263 * Returns: a garbage collector generation number
266 mono_gc_get_generation (MonoObject *object)
272 * mono_gc_collection_count:
273 * @generation: a GC generation number
275 * Get how many times a garbage collection has been performed
276 * for the given @generation number.
278 * Returns: the number of garbage collections
281 mono_gc_collection_count (int generation)
287 * mono_gc_add_memory_pressure:
288 * @value: amount of bytes
290 * Adjust the garbage collector's view of how many bytes of memory
291 * are indirectly referenced by managed objects (for example unmanaged
292 * memory holding image or other binary data).
293 * This is a hint only to the garbage collector algorithm.
294 * Note that negative amounts of @value will decrease the memory
298 mono_gc_add_memory_pressure (gint64 value)
303 * mono_gc_get_used_size:
305 * Get the approximate amount of memory used by managed objects.
307 * Returns: the amount of memory used in bytes
310 mono_gc_get_used_size (void)
312 return GC_get_heap_size () - GC_get_free_bytes ();
316 * mono_gc_get_heap_size:
318 * Get the amount of memory used by the garbage collector.
320 * Returns: the size of the heap in bytes
323 mono_gc_get_heap_size (void)
325 return GC_get_heap_size ();
329 mono_gc_is_gc_thread (void)
331 return GC_thread_is_registered ();
334 extern int GC_thread_register_foreign (void *base_addr);
337 mono_gc_register_thread (void *baseptr)
339 return mono_thread_info_attach (baseptr) != NULL;
343 boehm_thread_register (MonoThreadInfo* info, void *baseptr)
345 if (mono_gc_is_gc_thread())
347 #if !defined(HOST_WIN32)
348 return GC_thread_register_foreign (baseptr) ? info : NULL;
355 boehm_thread_unregister (MonoThreadInfo *p)
357 MonoNativeThreadId tid;
359 tid = mono_thread_info_get_tid (p);
361 if (p->runtime_thread)
362 mono_threads_add_joinable_thread ((gpointer)tid);
366 mono_object_is_alive (MonoObject* o)
368 return GC_is_marked ((gpointer)o);
372 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
377 static gint64 gc_start_time;
380 on_gc_notification (GCEventType event)
382 MonoGCEvent e = (MonoGCEvent)event;
385 case MONO_GC_EVENT_PRE_STOP_WORLD:
386 MONO_GC_WORLD_STOP_BEGIN ();
387 mono_thread_info_suspend_lock ();
390 case MONO_GC_EVENT_POST_STOP_WORLD:
391 MONO_GC_WORLD_STOP_END ();
394 case MONO_GC_EVENT_PRE_START_WORLD:
395 MONO_GC_WORLD_RESTART_BEGIN (1);
398 case MONO_GC_EVENT_POST_START_WORLD:
399 MONO_GC_WORLD_RESTART_END (1);
400 mono_thread_info_suspend_unlock ();
403 case MONO_GC_EVENT_START:
405 #ifndef DISABLE_PERFCOUNTERS
406 if (mono_perfcounters)
407 mono_perfcounters->gc_collections0++;
409 gc_stats.major_gc_count ++;
410 gc_start_time = mono_100ns_ticks ();
413 case MONO_GC_EVENT_END:
415 #if defined(ENABLE_DTRACE) && defined(__sun__)
416 /* This works around a dtrace -G problem on Solaris.
417 Limit its actual use to when the probe is enabled. */
418 if (MONO_GC_END_ENABLED ())
422 #ifndef DISABLE_PERFCOUNTERS
423 if (mono_perfcounters) {
424 guint64 heap_size = GC_get_heap_size ();
425 guint64 used_size = heap_size - GC_get_free_bytes ();
426 mono_perfcounters->gc_total_bytes = used_size;
427 mono_perfcounters->gc_committed_bytes = heap_size;
428 mono_perfcounters->gc_reserved_bytes = heap_size;
429 mono_perfcounters->gc_gen0size = heap_size;
432 gc_stats.major_gc_time += mono_100ns_ticks () - gc_start_time;
433 mono_trace_message (MONO_TRACE_GC, "gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
439 mono_profiler_gc_event (e, 0);
443 on_gc_heap_resize (size_t new_size)
445 guint64 heap_size = GC_get_heap_size ();
446 #ifndef DISABLE_PERFCOUNTERS
447 if (mono_perfcounters) {
448 mono_perfcounters->gc_committed_bytes = heap_size;
449 mono_perfcounters->gc_reserved_bytes = heap_size;
450 mono_perfcounters->gc_gen0size = heap_size;
453 mono_profiler_gc_heap_resize (new_size);
457 mono_gc_enable_events (void)
459 GC_notify_event = on_gc_notification;
460 GC_on_heap_resize = on_gc_heap_resize;
463 static gboolean alloc_events = FALSE;
466 mono_gc_enable_alloc_events (void)
472 mono_gc_register_root (char *start, size_t size, void *descr)
474 /* for some strange reason, they want one extra byte on the end */
475 GC_add_roots (start, start + size + 1);
481 mono_gc_deregister_root (char* addr)
484 /* FIXME: libgc doesn't define this work win32 for some reason */
485 /* FIXME: No size info */
486 GC_remove_roots (addr, addr + sizeof (gpointer) + 1);
491 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
493 /* libgc requires that we use HIDE_POINTER... */
494 *link_addr = (void*)HIDE_POINTER (obj);
496 GC_REGISTER_LONG_LINK (link_addr, obj);
498 GC_GENERAL_REGISTER_DISAPPEARING_LINK (link_addr, obj);
502 mono_gc_weak_link_remove (void **link_addr, gboolean track)
505 GC_unregister_long_link (link_addr);
507 GC_unregister_disappearing_link (link_addr);
512 reveal_link (gpointer link_addr)
514 void **link_a = link_addr;
515 return REVEAL_POINTER (*link_a);
519 mono_gc_weak_link_get (void **link_addr)
521 MonoObject *obj = GC_call_with_alloc_lock (reveal_link, link_addr);
522 if (obj == (MonoObject *) -1)
528 mono_gc_make_descr_for_string (gsize *bitmap, int numbits)
530 return mono_gc_make_descr_from_bitmap (bitmap, numbits);
534 mono_gc_make_descr_for_object (gsize *bitmap, int numbits, size_t obj_size)
536 return mono_gc_make_descr_from_bitmap (bitmap, numbits);
540 mono_gc_make_descr_for_array (int vector, gsize *elem_bitmap, int numbits, size_t elem_size)
542 /* libgc has no usable support for arrays... */
543 return GC_NO_DESCRIPTOR;
547 mono_gc_make_descr_from_bitmap (gsize *bitmap, int numbits)
549 /* It seems there are issues when the bitmap doesn't fit: play it safe */
551 return GC_NO_DESCRIPTOR;
553 return (gpointer)GC_make_descriptor ((GC_bitmap)bitmap, numbits);
557 mono_gc_make_root_descr_all_refs (int numbits)
563 mono_gc_alloc_fixed (size_t size, void *descr)
565 /* To help track down typed allocation bugs */
569 if (count == atoi (g_getenv ("COUNT2")))
571 if (count > atoi (g_getenv ("COUNT2")))
572 return GC_MALLOC (size);
576 return GC_MALLOC_EXPLICITLY_TYPED (size, (GC_descr)descr);
578 return GC_MALLOC (size);
582 mono_gc_free_fixed (void* addr)
587 mono_gc_alloc_obj (MonoVTable *vtable, size_t size)
591 if (!vtable->klass->has_references) {
592 obj = GC_MALLOC_ATOMIC (size);
594 obj->vtable = vtable;
595 obj->synchronisation = NULL;
597 memset ((char *) obj + sizeof (MonoObject), 0, size - sizeof (MonoObject));
598 } else if (vtable->gc_descr != GC_NO_DESCRIPTOR) {
599 obj = GC_GCJ_MALLOC (size, vtable);
601 obj = GC_MALLOC (size);
603 obj->vtable = vtable;
606 if (G_UNLIKELY (alloc_events))
607 mono_profiler_allocation (obj);
613 mono_gc_alloc_vector (MonoVTable *vtable, size_t size, uintptr_t max_length)
617 if (!vtable->klass->has_references) {
618 obj = GC_MALLOC_ATOMIC (size);
620 obj->obj.vtable = vtable;
621 obj->obj.synchronisation = NULL;
623 memset ((char *) obj + sizeof (MonoObject), 0, size - sizeof (MonoObject));
624 } else if (vtable->gc_descr != GC_NO_DESCRIPTOR) {
625 obj = GC_GCJ_MALLOC (size, vtable);
627 obj = GC_MALLOC (size);
629 obj->obj.vtable = vtable;
632 obj->max_length = max_length;
634 if (G_UNLIKELY (alloc_events))
635 mono_profiler_allocation (&obj->obj);
641 mono_gc_alloc_array (MonoVTable *vtable, size_t size, uintptr_t max_length, uintptr_t bounds_size)
645 if (!vtable->klass->has_references) {
646 obj = GC_MALLOC_ATOMIC (size);
648 obj->obj.vtable = vtable;
649 obj->obj.synchronisation = NULL;
651 memset ((char *) obj + sizeof (MonoObject), 0, size - sizeof (MonoObject));
652 } else if (vtable->gc_descr != GC_NO_DESCRIPTOR) {
653 obj = GC_GCJ_MALLOC (size, vtable);
655 obj = GC_MALLOC (size);
657 obj->obj.vtable = vtable;
660 obj->max_length = max_length;
663 obj->bounds = (MonoArrayBounds *) ((char *) obj + size - bounds_size);
665 if (G_UNLIKELY (alloc_events))
666 mono_profiler_allocation (&obj->obj);
672 mono_gc_alloc_string (MonoVTable *vtable, size_t size, gint32 len)
674 MonoString *obj = GC_MALLOC_ATOMIC (size);
676 obj->object.vtable = vtable;
677 obj->object.synchronisation = NULL;
679 obj->chars [len] = 0;
681 if (G_UNLIKELY (alloc_events))
682 mono_profiler_allocation (&obj->object);
688 mono_gc_invoke_finalizers (void)
690 /* There is a bug in GC_invoke_finalizer () in versions <= 6.2alpha4:
691 * the 'mem_freed' variable is not initialized when there are no
692 * objects to finalize, which leads to strange behavior later on.
693 * The check is necessary to work around that bug.
695 if (GC_should_invoke_finalizers ())
696 return GC_invoke_finalizers ();
701 mono_gc_pending_finalizers (void)
703 return GC_should_invoke_finalizers ();
707 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
709 *(void**)field_ptr = value;
713 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
715 *(void**)slot_ptr = value;
719 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
721 mono_gc_memmove_aligned (dest_ptr, src_ptr, count * sizeof (gpointer));
725 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
727 *(void**)ptr = value;
731 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, MonoObject *value)
733 InterlockedWritePointer (ptr, value);
737 mono_gc_wbarrier_generic_nostore (gpointer ptr)
742 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
744 mono_gc_memmove_atomic (dest, src, count * mono_class_value_size (klass, NULL));
748 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
750 /* do not copy the sync state */
751 mono_gc_memmove_aligned ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
752 mono_object_class (obj)->instance_size - sizeof (MonoObject));
756 mono_gc_clear_domain (MonoDomain *domain)
761 mono_gc_get_suspend_signal (void)
763 return GC_get_suspend_signal ();
767 mono_gc_get_restart_signal (void)
769 return GC_get_restart_signal ();
772 #if defined(USE_COMPILER_TLS) && defined(__linux__) && (defined(__i386__) || defined(__x86_64__))
773 extern __thread MONO_TLS_FAST void* GC_thread_tls;
774 #include "metadata-internals.h"
780 while (!(v & (1 << i)))
787 ATYPE_FREEPTR_FOR_BOX,
795 create_allocator (int atype, int tls_key, gboolean slowpath)
797 int index_var, bytes_var, my_fl_var, my_entry_var;
798 guint32 no_freelist_branch, not_small_enough_branch = 0;
799 guint32 size_overflow_branch = 0;
800 MonoMethodBuilder *mb;
802 MonoMethodSignature *csig;
803 const char *name = NULL;
804 AllocatorWrapperInfo *info;
806 if (atype == ATYPE_FREEPTR) {
807 name = slowpath ? "SlowAllocPtrfree" : "AllocPtrfree";
808 } else if (atype == ATYPE_FREEPTR_FOR_BOX) {
809 name = slowpath ? "SlowAllocPtrfreeBox" : "AllocPtrfreeBox";
810 } else if (atype == ATYPE_NORMAL) {
811 name = slowpath ? "SlowAlloc" : "Alloc";
812 } else if (atype == ATYPE_GCJ) {
813 name = slowpath ? "SlowAllocGcj" : "AllocGcj";
814 } else if (atype == ATYPE_STRING) {
815 name = slowpath ? "SlowAllocString" : "AllocString";
817 g_assert_not_reached ();
820 csig = mono_metadata_signature_alloc (mono_defaults.corlib, 2);
822 if (atype == ATYPE_STRING) {
823 csig->ret = &mono_defaults.string_class->byval_arg;
824 csig->params [0] = &mono_defaults.int_class->byval_arg;
825 csig->params [1] = &mono_defaults.int32_class->byval_arg;
827 csig->ret = &mono_defaults.object_class->byval_arg;
828 csig->params [0] = &mono_defaults.int_class->byval_arg;
829 csig->params [1] = &mono_defaults.int32_class->byval_arg;
832 mb = mono_mb_new (mono_defaults.object_class, name, MONO_WRAPPER_ALLOC);
835 goto always_slowpath;
837 bytes_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
838 if (atype == ATYPE_STRING) {
839 /* a string alloator method takes the args: (vtable, len) */
840 /* bytes = (offsetof (MonoString, chars) + ((len + 1) * 2)); */
841 mono_mb_emit_ldarg (mb, 1);
842 mono_mb_emit_icon (mb, 1);
843 mono_mb_emit_byte (mb, MONO_CEE_ADD);
844 mono_mb_emit_icon (mb, 1);
845 mono_mb_emit_byte (mb, MONO_CEE_SHL);
846 // sizeof (MonoString) might include padding
847 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, chars));
848 mono_mb_emit_byte (mb, MONO_CEE_ADD);
849 mono_mb_emit_stloc (mb, bytes_var);
851 mono_mb_emit_ldarg (mb, 1);
852 mono_mb_emit_stloc (mb, bytes_var);
855 /* this is needed for strings/arrays only as the other big types are never allocated with this method */
856 if (atype == ATYPE_STRING) {
858 /* if (!SMALL_ENOUGH (bytes)) jump slow_path;*/
859 mono_mb_emit_ldloc (mb, bytes_var);
860 mono_mb_emit_icon (mb, (NFREELISTS-1) * GRANULARITY);
861 not_small_enough_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S);
862 /* check for overflow */
863 mono_mb_emit_ldloc (mb, bytes_var);
864 mono_mb_emit_icon (mb, sizeof (MonoString));
865 size_overflow_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLE_UN_S);
868 /* int index = INDEX_FROM_BYTES(bytes); */
869 index_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
871 mono_mb_emit_ldloc (mb, bytes_var);
872 mono_mb_emit_icon (mb, GRANULARITY - 1);
873 mono_mb_emit_byte (mb, MONO_CEE_ADD);
874 mono_mb_emit_icon (mb, shift_amount (GRANULARITY));
875 mono_mb_emit_byte (mb, MONO_CEE_SHR_UN);
876 mono_mb_emit_icon (mb, shift_amount (sizeof (gpointer)));
877 mono_mb_emit_byte (mb, MONO_CEE_SHL);
878 /* index var is already adjusted into bytes */
879 mono_mb_emit_stloc (mb, index_var);
881 my_fl_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
882 my_entry_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
883 /* my_fl = ((GC_thread)tsd) -> ptrfree_freelists + index; */
884 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
885 mono_mb_emit_byte (mb, 0x0D); /* CEE_MONO_TLS */
886 mono_mb_emit_i4 (mb, tls_key);
887 if (atype == ATYPE_FREEPTR || atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING)
888 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, ptrfree_freelists));
889 else if (atype == ATYPE_NORMAL)
890 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, normal_freelists));
891 else if (atype == ATYPE_GCJ)
892 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, gcj_freelists));
894 g_assert_not_reached ();
895 mono_mb_emit_byte (mb, MONO_CEE_ADD);
896 mono_mb_emit_ldloc (mb, index_var);
897 mono_mb_emit_byte (mb, MONO_CEE_ADD);
898 mono_mb_emit_stloc (mb, my_fl_var);
900 /* my_entry = *my_fl; */
901 mono_mb_emit_ldloc (mb, my_fl_var);
902 mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
903 mono_mb_emit_stloc (mb, my_entry_var);
905 /* if (EXPECT((word)my_entry >= HBLKSIZE, 1)) { */
906 mono_mb_emit_ldloc (mb, my_entry_var);
907 mono_mb_emit_icon (mb, HBLKSIZE);
908 no_freelist_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
910 /* ptr_t next = obj_link(my_entry); *my_fl = next; */
911 mono_mb_emit_ldloc (mb, my_fl_var);
912 mono_mb_emit_ldloc (mb, my_entry_var);
913 mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
914 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
916 /* set the vtable and clear the words in the object */
917 mono_mb_emit_ldloc (mb, my_entry_var);
918 mono_mb_emit_ldarg (mb, 0);
919 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
921 if (atype == ATYPE_FREEPTR) {
922 int start_var, end_var, start_loop;
923 /* end = my_entry + bytes; start = my_entry + sizeof (gpointer);
925 start_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
926 end_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
927 mono_mb_emit_ldloc (mb, my_entry_var);
928 mono_mb_emit_ldloc (mb, bytes_var);
929 mono_mb_emit_byte (mb, MONO_CEE_ADD);
930 mono_mb_emit_stloc (mb, end_var);
931 mono_mb_emit_ldloc (mb, my_entry_var);
932 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
933 mono_mb_emit_byte (mb, MONO_CEE_ADD);
934 mono_mb_emit_stloc (mb, start_var);
938 * } while (start < end);
940 start_loop = mono_mb_get_label (mb);
941 mono_mb_emit_ldloc (mb, start_var);
942 mono_mb_emit_icon (mb, 0);
943 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
944 mono_mb_emit_ldloc (mb, start_var);
945 mono_mb_emit_icon (mb, sizeof (gpointer));
946 mono_mb_emit_byte (mb, MONO_CEE_ADD);
947 mono_mb_emit_stloc (mb, start_var);
949 mono_mb_emit_ldloc (mb, start_var);
950 mono_mb_emit_ldloc (mb, end_var);
951 mono_mb_emit_byte (mb, MONO_CEE_BLT_UN_S);
952 mono_mb_emit_byte (mb, start_loop - (mono_mb_get_label (mb) + 1));
953 } else if (atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING) {
954 /* need to clear just the sync pointer */
955 mono_mb_emit_ldloc (mb, my_entry_var);
956 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
957 mono_mb_emit_byte (mb, MONO_CEE_ADD);
958 mono_mb_emit_icon (mb, 0);
959 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
962 if (atype == ATYPE_STRING) {
963 /* need to set length and clear the last char */
964 /* s->length = len; */
965 mono_mb_emit_ldloc (mb, my_entry_var);
966 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, length));
967 mono_mb_emit_byte (mb, MONO_CEE_ADD);
968 mono_mb_emit_ldarg (mb, 1);
969 mono_mb_emit_byte (mb, MONO_CEE_STIND_I4);
970 /* s->chars [len] = 0; */
971 mono_mb_emit_ldloc (mb, my_entry_var);
972 mono_mb_emit_ldloc (mb, bytes_var);
973 mono_mb_emit_icon (mb, 2);
974 mono_mb_emit_byte (mb, MONO_CEE_SUB);
975 mono_mb_emit_byte (mb, MONO_CEE_ADD);
976 mono_mb_emit_icon (mb, 0);
977 mono_mb_emit_byte (mb, MONO_CEE_STIND_I2);
980 /* return my_entry; */
981 mono_mb_emit_ldloc (mb, my_entry_var);
982 mono_mb_emit_byte (mb, MONO_CEE_RET);
984 mono_mb_patch_short_branch (mb, no_freelist_branch);
985 if (not_small_enough_branch > 0)
986 mono_mb_patch_short_branch (mb, not_small_enough_branch);
987 if (size_overflow_branch > 0)
988 mono_mb_patch_short_branch (mb, size_overflow_branch);
990 /* the slow path: we just call back into the runtime */
992 if (atype == ATYPE_STRING) {
993 mono_mb_emit_ldarg (mb, 1);
994 mono_mb_emit_icall (mb, mono_string_alloc);
996 mono_mb_emit_ldarg (mb, 0);
997 mono_mb_emit_icall (mb, mono_object_new_specific);
1000 mono_mb_emit_byte (mb, MONO_CEE_RET);
1002 res = mono_mb_create_method (mb, csig, 8);
1004 mono_method_get_header (res)->init_locals = FALSE;
1006 info = mono_image_alloc0 (mono_defaults.corlib, sizeof (AllocatorWrapperInfo));
1007 info->gc_name = "boehm";
1008 info->alloc_type = atype;
1009 mono_marshal_set_wrapper_info (res, info);
1014 static MonoMethod* alloc_method_cache [ATYPE_NUM];
1015 static MonoMethod* slowpath_alloc_method_cache [ATYPE_NUM];
1017 static G_GNUC_UNUSED gboolean
1018 mono_gc_is_critical_method (MonoMethod *method)
1022 for (i = 0; i < ATYPE_NUM; ++i)
1023 if (method == alloc_method_cache [i] || method == slowpath_alloc_method_cache [i])
1030 * If possible, generate a managed method that can quickly allocate objects in class
1031 * @klass. The method will typically have an thread-local inline allocation sequence.
1032 * The signature of the called method is:
1033 * object allocate (MonoVTable *vtable)
1034 * Some of the logic here is similar to mono_class_get_allocation_ftn () i object.c,
1036 * The thread local alloc logic is taken from libgc/pthread_support.c.
1040 mono_gc_get_managed_allocator (MonoClass *klass, gboolean for_box, gboolean known_instance_size)
1044 MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
1046 /*g_print ("thread tls: %d\n", offset);*/
1049 if (!SMALL_ENOUGH (klass->instance_size))
1051 if (mono_class_has_finalizer (klass) || mono_class_is_marshalbyref (klass) || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS))
1055 if (mono_class_is_open_constructed_type (&klass->byval_arg))
1057 if (klass->byval_arg.type == MONO_TYPE_STRING) {
1058 atype = ATYPE_STRING;
1059 } else if (!klass->has_references) {
1061 atype = ATYPE_FREEPTR_FOR_BOX;
1063 atype = ATYPE_FREEPTR;
1067 * disabled because we currently do a runtime choice anyway, to
1068 * deal with multiple appdomains.
1069 if (vtable->gc_descr != GC_NO_DESCRIPTOR)
1072 atype = ATYPE_NORMAL;
1075 return mono_gc_get_managed_allocator_by_type (atype, FALSE);
1079 mono_gc_get_managed_array_allocator (MonoClass *klass)
1085 * mono_gc_get_managed_allocator_by_type:
1087 * Return a managed allocator method corresponding to allocator type ATYPE.
1090 mono_gc_get_managed_allocator_by_type (int atype, gboolean slowpath)
1094 MonoMethod **cache = slowpath ? slowpath_alloc_method_cache : alloc_method_cache;
1095 MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
1097 mono_tls_key_set_offset (TLS_KEY_BOEHM_GC_THREAD, offset);
1099 res = cache [atype];
1103 res = create_allocator (atype, TLS_KEY_BOEHM_GC_THREAD, slowpath);
1104 mono_mutex_lock (&mono_gc_lock);
1105 if (cache [atype]) {
1106 mono_free_method (res);
1107 res = cache [atype];
1109 mono_memory_barrier ();
1110 cache [atype] = res;
1112 mono_mutex_unlock (&mono_gc_lock);
1117 mono_gc_get_managed_allocator_types (void)
1123 mono_gc_get_write_barrier (void)
1125 g_assert_not_reached ();
1131 static G_GNUC_UNUSED gboolean
1132 mono_gc_is_critical_method (MonoMethod *method)
1138 mono_gc_get_managed_allocator (MonoClass *klass, gboolean for_box, gboolean known_instance_size)
1144 mono_gc_get_managed_array_allocator (MonoClass *klass)
1150 mono_gc_get_managed_allocator_by_type (int atype, gboolean slowpath)
1156 mono_gc_get_managed_allocator_types (void)
1162 mono_gc_get_write_barrier (void)
1164 g_assert_not_reached ();
1171 mono_gc_get_specific_write_barrier (gboolean is_concurrent)
1173 g_assert_not_reached ();
1178 mono_gc_get_aligned_size_for_allocator (int size)
1184 mono_gc_get_gc_name (void)
1190 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
1192 return GC_call_with_alloc_lock (func, data);
1196 mono_gc_get_description (void)
1198 return g_strdup (DEFAULT_GC_NAME);
1202 mono_gc_set_desktop_mode (void)
1208 mono_gc_is_moving (void)
1214 mono_gc_is_disabled (void)
1216 if (GC_dont_gc || g_getenv ("GC_DONT_GC"))
1223 mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
1225 g_assert_not_reached ();
1230 mono_gc_get_card_table (int *shift_bits, gpointer *card_mask)
1232 g_assert_not_reached ();
1237 mono_gc_card_table_nursery_check (void)
1239 g_assert_not_reached ();
1244 mono_gc_get_nursery (int *shift_bits, size_t *size)
1250 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1255 mono_gc_precise_stack_mark_enabled (void)
1261 mono_gc_get_logfile (void)
1267 mono_gc_conservatively_scan_area (void *start, void *end)
1269 g_assert_not_reached ();
1273 mono_gc_scan_object (void *obj, void *gc_data)
1275 g_assert_not_reached ();
1280 mono_gc_get_bitmap_for_descr (void *descr, int *numbits)
1282 g_assert_not_reached ();
1287 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
1292 mono_gc_set_stack_end (void *stack_end)
1296 void mono_gc_set_skip_thread (gboolean value)
1301 mono_gc_register_for_finalization (MonoObject *obj, void *user_data)
1306 /* This assertion is not valid when GC_DEBUG is defined */
1307 g_assert (GC_base (obj) == (char*)obj - offset);
1310 GC_REGISTER_FINALIZER_NO_ORDER ((char*)obj - offset, user_data, GUINT_TO_POINTER (offset), NULL, NULL);
1315 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
1317 /* it is being replaced by GC_pthread_create on some
1318 * platforms, see libgc/include/gc_pthread_redirects.h */
1319 return pthread_create (new_thread, attr, start_routine, arg);
1324 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
1326 return GC_DllMain (module_handle, reason, reserved);
1331 mono_gc_get_vtable_bits (MonoClass *class)
1333 if (fin_callbacks.is_class_finalization_aware) {
1334 if (fin_callbacks.is_class_finalization_aware (class))
1335 return BOEHM_GC_BIT_FINALIZER_AWARE;
1341 * mono_gc_register_altstack:
1343 * Register the dimensions of the normal stack and altstack with the collector.
1344 * Currently, STACK/STACK_SIZE is only used when the thread is suspended while it is on an altstack.
1347 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
1349 GC_register_altstack (stack, stack_size, altstack, altstack_size);
1353 mono_gc_get_los_limit (void)
1359 mono_gc_set_string_length (MonoString *str, gint32 new_length)
1361 mono_unichar2 *new_end = str->chars + new_length;
1363 /* zero the discarded string. This null-delimits the string and allows
1364 * the space to be reclaimed by SGen. */
1366 memset (new_end, 0, (str->length - new_length + 1) * sizeof (mono_unichar2));
1367 str->length = new_length;
1371 mono_gc_user_markers_supported (void)
1377 mono_gc_make_root_descr_user (MonoGCRootMarkFunc marker)
1379 g_assert_not_reached ();
1384 mono_gc_set_allow_synchronous_major (gboolean flag)
1388 /* Toggleref support */
1391 mono_gc_toggleref_add (MonoObject *object, mono_bool strong_ref)
1393 GC_toggleref_add ((GC_PTR)object, (int)strong_ref);
1397 mono_gc_toggleref_register_callback (MonoToggleRefStatus (*proccess_toggleref) (MonoObject *obj))
1399 GC_toggleref_register_callback ((int (*) (GC_PTR obj)) proccess_toggleref);
1402 /* Test support code */
1404 static MonoToggleRefStatus
1405 test_toggleref_callback (MonoObject *obj)
1407 static MonoClassField *mono_toggleref_test_field;
1408 int status = MONO_TOGGLE_REF_DROP;
1410 if (!mono_toggleref_test_field) {
1411 mono_toggleref_test_field = mono_class_get_field_from_name (mono_object_get_class (obj), "__test");
1412 g_assert (mono_toggleref_test_field);
1415 mono_field_get_value (obj, mono_toggleref_test_field, &status);
1416 printf ("toggleref-cb obj %d\n", status);
1421 register_test_toggleref_callback (void)
1423 mono_gc_toggleref_register_callback (test_toggleref_callback);
1427 is_finalization_aware (MonoObject *obj)
1429 MonoVTable *vt = obj->vtable;
1430 return (vt->gc_bits & BOEHM_GC_BIT_FINALIZER_AWARE) == BOEHM_GC_BIT_FINALIZER_AWARE;
1434 fin_notifier (MonoObject *obj)
1436 if (is_finalization_aware (obj))
1437 fin_callbacks.object_queued_for_finalization (obj);
1441 mono_gc_register_finalizer_callbacks (MonoGCFinalizerCallbacks *callbacks)
1443 if (callbacks->version != MONO_GC_FINALIZER_EXTENSION_VERSION)
1444 g_error ("Invalid finalizer callback version. Expected %d but got %d\n", MONO_GC_FINALIZER_EXTENSION_VERSION, callbacks->version);
1446 fin_callbacks = *callbacks;
1448 GC_set_finalizer_notify_proc ((void (*) (GC_PTR))fin_notifier);
1452 mono_gc_is_null (void)
1457 #endif /* no Boehm GC */