2 * sgen-mono.c: SGen features specific to Mono.
4 * Copyright (C) 2014 Xamarin Inc
6 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
12 #include "sgen/sgen-gc.h"
13 #include "sgen/sgen-protocol.h"
14 #include "metadata/monitor.h"
15 #include "sgen/sgen-layout-stats.h"
16 #include "sgen/sgen-client.h"
17 #include "sgen/sgen-cardtable.h"
18 #include "sgen/sgen-pinning.h"
19 #include "sgen/sgen-thread-pool.h"
20 #include "metadata/marshal.h"
21 #include "metadata/method-builder.h"
22 #include "metadata/abi-details.h"
23 #include "metadata/mono-gc.h"
24 #include "metadata/runtime.h"
25 #include "metadata/sgen-bridge-internals.h"
26 #include "metadata/gc-internals.h"
27 #include "metadata/handle.h"
28 #include "utils/mono-memory-model.h"
29 #include "utils/mono-logger-internals.h"
30 #include "utils/mono-threads-coop.h"
31 #include "utils/mono-threads.h"
32 #include "metadata/w32handle.h"
34 #ifdef HEAVY_STATISTICS
35 static guint64 stat_wbarrier_set_arrayref = 0;
36 static guint64 stat_wbarrier_value_copy = 0;
37 static guint64 stat_wbarrier_object_copy = 0;
39 static guint64 los_marked_cards;
40 static guint64 los_array_cards;
41 static guint64 los_array_remsets;
44 /* If set, mark stacks conservatively, even if precise marking is possible */
45 static gboolean conservative_stack_mark = FALSE;
46 /* If set, check that there are no references to the domain left at domain unload */
47 gboolean sgen_mono_xdomain_checks = FALSE;
49 /* Functions supplied by the runtime to be called by the GC */
50 static MonoGCCallbacks gc_callbacks;
52 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
54 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
58 #include "mono/cil/opcode.def"
69 ptr_on_stack (void *ptr)
71 gpointer stack_start = &stack_start;
72 SgenThreadInfo *info = mono_thread_info_current ();
74 if (ptr >= stack_start && ptr < (gpointer)info->client_info.stack_end)
79 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
81 #define HANDLE_PTR(ptr,obj) do { \
82 gpointer o = *(gpointer*)(ptr); \
84 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
85 binary_protocol_wbarrier (d, o, (gpointer) SGEN_LOAD_VTABLE (o)); \
90 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
92 #define SCAN_OBJECT_NOVTABLE
93 #include "sgen/sgen-scan-object.h"
98 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
100 HEAVY_STAT (++stat_wbarrier_value_copy);
101 g_assert (klass->valuetype);
103 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, (gpointer)klass->gc_descr, klass->name, klass);
105 if (sgen_ptr_in_nursery (dest) || ptr_on_stack (dest) || !sgen_gc_descr_has_references ((mword)klass->gc_descr)) {
106 size_t element_size = mono_class_value_size (klass, NULL);
107 size_t size = count * element_size;
108 mono_gc_memmove_atomic (dest, src, size);
112 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
113 if (binary_protocol_is_heavy_enabled ()) {
114 size_t element_size = mono_class_value_size (klass, NULL);
116 for (i = 0; i < count; ++i) {
117 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
118 (char*)src + i * element_size - sizeof (MonoObject),
119 (mword) klass->gc_descr);
124 sgen_get_remset ()->wbarrier_value_copy (dest, src, count, mono_class_value_size (klass, NULL));
128 * mono_gc_wbarrier_object_copy:
130 * Write barrier to call when obj is the result of a clone or copy of an object.
133 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
137 HEAVY_STAT (++stat_wbarrier_object_copy);
139 SGEN_ASSERT (6, !ptr_on_stack (obj), "Why is this called for a non-reference type?");
140 if (sgen_ptr_in_nursery (obj) || !SGEN_OBJECT_HAS_REFERENCES (src)) {
141 size = mono_object_class (obj)->instance_size;
142 mono_gc_memmove_aligned ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
143 size - sizeof (MonoObject));
147 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
148 if (binary_protocol_is_heavy_enabled ())
149 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
152 sgen_get_remset ()->wbarrier_object_copy (obj, src);
156 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
158 HEAVY_STAT (++stat_wbarrier_set_arrayref);
159 if (sgen_ptr_in_nursery (slot_ptr)) {
160 *(void**)slot_ptr = value;
163 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
165 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
167 sgen_get_remset ()->wbarrier_set_field ((GCObject*)arr, slot_ptr, value);
171 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
173 mono_gc_wbarrier_set_arrayref ((MonoArray*)obj, field_ptr, value);
177 mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
179 sgen_wbarrier_value_copy_bitmap (_dest, _src, size, bitmap);
183 mono_gc_get_suspend_signal (void)
185 return mono_threads_suspend_get_suspend_signal ();
189 mono_gc_get_restart_signal (void)
191 return mono_threads_suspend_get_restart_signal ();
194 static MonoMethod *write_barrier_conc_method;
195 static MonoMethod *write_barrier_noconc_method;
198 sgen_is_critical_method (MonoMethod *method)
200 return sgen_is_managed_allocator (method);
204 sgen_has_critical_method (void)
206 return sgen_has_managed_allocator ();
210 ip_in_critical_region (MonoDomain *domain, gpointer ip)
216 * We pass false for 'try_aot' so this becomes async safe.
217 * It won't find aot methods whose jit info is not yet loaded,
218 * so we preload their jit info in the JIT.
220 ji = mono_jit_info_table_find_internal (domain, ip, FALSE, FALSE);
224 method = mono_jit_info_get_method (ji);
226 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
230 mono_gc_is_critical_method (MonoMethod *method)
232 return sgen_is_critical_method (method);
238 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels, gboolean is_concurrent)
240 int shifted_nursery_start = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
242 memset (nursery_check_return_labels, 0, sizeof (int) * 2);
243 // if (ptr_in_nursery (ptr)) return;
245 * Masking out the bits might be faster, but we would have to use 64 bit
246 * immediates, which might be slower.
248 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
249 mono_mb_emit_byte (mb, CEE_MONO_LDPTR_NURSERY_START);
250 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
251 mono_mb_emit_byte (mb, CEE_MONO_LDPTR_NURSERY_BITS);
252 mono_mb_emit_byte (mb, CEE_SHR_UN);
253 mono_mb_emit_stloc (mb, shifted_nursery_start);
255 mono_mb_emit_ldarg (mb, 0);
256 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
257 mono_mb_emit_byte (mb, CEE_MONO_LDPTR_NURSERY_BITS);
258 mono_mb_emit_byte (mb, CEE_SHR_UN);
259 mono_mb_emit_ldloc (mb, shifted_nursery_start);
260 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
262 if (!is_concurrent) {
263 // if (!ptr_in_nursery (*ptr)) return;
264 mono_mb_emit_ldarg (mb, 0);
265 mono_mb_emit_byte (mb, CEE_LDIND_I);
266 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
267 mono_mb_emit_byte (mb, CEE_MONO_LDPTR_NURSERY_BITS);
268 mono_mb_emit_byte (mb, CEE_SHR_UN);
269 mono_mb_emit_ldloc (mb, shifted_nursery_start);
270 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
276 mono_gc_get_specific_write_barrier (gboolean is_concurrent)
279 MonoMethodBuilder *mb;
280 MonoMethodSignature *sig;
281 MonoMethod **write_barrier_method_addr;
283 #ifdef MANAGED_WBARRIER
284 int i, nursery_check_labels [2];
287 // FIXME: Maybe create a separate version for ctors (the branch would be
288 // correctly predicted more times)
290 write_barrier_method_addr = &write_barrier_conc_method;
292 write_barrier_method_addr = &write_barrier_noconc_method;
294 if (*write_barrier_method_addr)
295 return *write_barrier_method_addr;
297 /* Create the IL version of mono_gc_barrier_generic_store () */
298 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
299 sig->ret = &mono_defaults.void_class->byval_arg;
300 sig->params [0] = &mono_defaults.int_class->byval_arg;
303 mb = mono_mb_new (mono_defaults.object_class, "wbarrier_conc", MONO_WRAPPER_WRITE_BARRIER);
305 mb = mono_mb_new (mono_defaults.object_class, "wbarrier_noconc", MONO_WRAPPER_WRITE_BARRIER);
308 #ifdef MANAGED_WBARRIER
309 emit_nursery_check (mb, nursery_check_labels, is_concurrent);
311 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
315 LDC_PTR sgen_cardtable
321 if (SGEN_HAVE_OVERLAPPING_CARDS) {
322 LDC_PTR card_table_mask
329 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
330 mono_mb_emit_byte (mb, CEE_MONO_LDPTR_CARD_TABLE);
331 mono_mb_emit_ldarg (mb, 0);
332 mono_mb_emit_icon (mb, CARD_BITS);
333 mono_mb_emit_byte (mb, CEE_SHR_UN);
334 mono_mb_emit_byte (mb, CEE_CONV_I);
335 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
336 #if SIZEOF_VOID_P == 8
337 mono_mb_emit_icon8 (mb, CARD_MASK);
339 mono_mb_emit_icon (mb, CARD_MASK);
341 mono_mb_emit_byte (mb, CEE_CONV_I);
342 mono_mb_emit_byte (mb, CEE_AND);
344 mono_mb_emit_byte (mb, CEE_ADD);
345 mono_mb_emit_icon (mb, 1);
346 mono_mb_emit_byte (mb, CEE_STIND_I1);
349 for (i = 0; i < 2; ++i) {
350 if (nursery_check_labels [i])
351 mono_mb_patch_branch (mb, nursery_check_labels [i]);
353 mono_mb_emit_byte (mb, CEE_RET);
355 mono_mb_emit_ldarg (mb, 0);
356 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
357 mono_mb_emit_byte (mb, CEE_RET);
360 res = mono_mb_create_method (mb, sig, 16);
361 info = mono_wrapper_info_create (mb, WRAPPER_SUBTYPE_NONE);
362 mono_marshal_set_wrapper_info (res, info);
366 if (*write_barrier_method_addr) {
367 /* Already created */
368 mono_free_method (res);
370 /* double-checked locking */
371 mono_memory_barrier ();
372 *write_barrier_method_addr = res;
376 return *write_barrier_method_addr;
380 mono_gc_get_write_barrier (void)
382 return mono_gc_get_specific_write_barrier (major_collector.is_concurrent);
386 * Dummy filler objects
389 /* Vtable of the objects used to fill out nursery fragments before a collection */
390 static GCVTable array_fill_vtable;
393 get_array_fill_vtable (void)
395 if (!array_fill_vtable) {
396 static MonoClass klass;
397 static char _vtable[sizeof(MonoVTable)+8];
398 MonoVTable* vtable = (MonoVTable*) ALIGN_TO((mword)_vtable, 8);
401 MonoDomain *domain = mono_get_root_domain ();
404 klass.element_class = mono_defaults.byte_class;
406 klass.instance_size = MONO_SIZEOF_MONO_ARRAY;
407 klass.sizes.element_size = 1;
408 klass.name = "array_filler_type";
410 vtable->klass = &klass;
412 vtable->gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
415 array_fill_vtable = vtable;
417 return array_fill_vtable;
421 sgen_client_array_fill_range (char *start, size_t size)
425 if (size < MONO_SIZEOF_MONO_ARRAY) {
426 memset (start, 0, size);
430 o = (MonoArray*)start;
431 o->obj.vtable = (MonoVTable*)get_array_fill_vtable ();
432 /* Mark this as not a real object */
433 o->obj.synchronisation = (MonoThreadsSync *)GINT_TO_POINTER (-1);
435 o->max_length = (mono_array_size_t)(size - MONO_SIZEOF_MONO_ARRAY);
441 sgen_client_zero_array_fill_header (void *p, size_t size)
443 if (size >= MONO_SIZEOF_MONO_ARRAY) {
444 memset (p, 0, MONO_SIZEOF_MONO_ARRAY);
446 static guint8 zeros [MONO_SIZEOF_MONO_ARRAY];
448 SGEN_ASSERT (0, !memcmp (p, zeros, size), "TLAB segment must be zeroed out.");
456 static MonoGCFinalizerCallbacks fin_callbacks;
459 mono_gc_get_vtable_bits (MonoClass *klass)
462 /* FIXME move this to the bridge code */
463 if (sgen_need_bridge_processing ()) {
464 switch (sgen_bridge_class_kind (klass)) {
465 case GC_BRIDGE_TRANSPARENT_BRIDGE_CLASS:
466 case GC_BRIDGE_OPAQUE_BRIDGE_CLASS:
467 res = SGEN_GC_BIT_BRIDGE_OBJECT;
469 case GC_BRIDGE_OPAQUE_CLASS:
470 res = SGEN_GC_BIT_BRIDGE_OPAQUE_OBJECT;
472 case GC_BRIDGE_TRANSPARENT_CLASS:
476 if (fin_callbacks.is_class_finalization_aware) {
477 if (fin_callbacks.is_class_finalization_aware (klass))
478 res |= SGEN_GC_BIT_FINALIZER_AWARE;
484 is_finalization_aware (MonoObject *obj)
486 MonoVTable *vt = SGEN_LOAD_VTABLE (obj);
487 return (vt->gc_bits & SGEN_GC_BIT_FINALIZER_AWARE) == SGEN_GC_BIT_FINALIZER_AWARE;
491 sgen_client_object_queued_for_finalization (GCObject *obj)
493 if (fin_callbacks.object_queued_for_finalization && is_finalization_aware (obj))
494 fin_callbacks.object_queued_for_finalization (obj);
497 if (G_UNLIKELY (MONO_GC_FINALIZE_ENQUEUE_ENABLED ())) {
498 int gen = sgen_ptr_in_nursery (obj) ? GENERATION_NURSERY : GENERATION_OLD;
499 GCVTable vt = SGEN_LOAD_VTABLE (obj);
500 MONO_GC_FINALIZE_ENQUEUE ((mword)obj, sgen_safe_object_get_size (obj),
501 sgen_client_vtable_get_namespace (vt), sgen_client_vtable_get_name (vt), gen,
502 sgen_client_object_has_critical_finalizer (obj));
508 mono_gc_register_finalizer_callbacks (MonoGCFinalizerCallbacks *callbacks)
510 if (callbacks->version != MONO_GC_FINALIZER_EXTENSION_VERSION)
511 g_error ("Invalid finalizer callback version. Expected %d but got %d\n", MONO_GC_FINALIZER_EXTENSION_VERSION, callbacks->version);
513 fin_callbacks = *callbacks;
517 sgen_client_run_finalize (MonoObject *obj)
519 mono_gc_run_finalize (obj, NULL);
523 mono_gc_invoke_finalizers (void)
525 return sgen_gc_invoke_finalizers ();
529 mono_gc_pending_finalizers (void)
531 return sgen_have_pending_finalizers ();
535 sgen_client_finalize_notify (void)
537 mono_gc_finalize_notify ();
541 mono_gc_register_for_finalization (MonoObject *obj, void *user_data)
543 sgen_object_register_for_finalization (obj, user_data);
547 object_in_domain_predicate (MonoObject *obj, void *user_data)
549 MonoDomain *domain = (MonoDomain *)user_data;
550 if (mono_object_domain (obj) == domain) {
551 SGEN_LOG (5, "Unregistering finalizer for object: %p (%s)", obj, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (obj)));
558 * mono_gc_finalizers_for_domain:
559 * @domain: the unloading appdomain
560 * @out_array: output array
561 * @out_size: size of output array
563 * Enqueue for finalization all objects that belong to the unloading appdomain @domain
564 * @suspend is used for early termination of the enqueuing process.
567 mono_gc_finalize_domain (MonoDomain *domain)
569 sgen_finalize_if (object_in_domain_predicate, domain);
573 mono_gc_suspend_finalizers (void)
575 sgen_set_suspend_finalizers ();
582 typedef struct _EphemeronLinkNode EphemeronLinkNode;
584 struct _EphemeronLinkNode {
585 EphemeronLinkNode *next;
594 static EphemeronLinkNode *ephemeron_list;
596 /* LOCKING: requires that the GC lock is held */
598 null_ephemerons_for_domain (MonoDomain *domain)
600 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
603 MonoObject *object = (MonoObject*)current->array;
606 SGEN_ASSERT (0, object->vtable, "Can't have objects without vtables.");
608 if (object && object->vtable->domain == domain) {
609 EphemeronLinkNode *tmp = current;
612 prev->next = current->next;
614 ephemeron_list = current->next;
616 current = current->next;
617 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
620 current = current->next;
625 /* LOCKING: requires that the GC lock is held */
627 sgen_client_clear_unreachable_ephemerons (ScanCopyContext ctx)
629 CopyOrMarkObjectFunc copy_func = ctx.ops->copy_or_mark_object;
630 SgenGrayQueue *queue = ctx.queue;
631 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
632 Ephemeron *cur, *array_end;
636 MonoArray *array = current->array;
638 if (!sgen_is_object_alive_for_current_gen ((GCObject*)array)) {
639 EphemeronLinkNode *tmp = current;
641 SGEN_LOG (5, "Dead Ephemeron array at %p", array);
644 prev->next = current->next;
646 ephemeron_list = current->next;
648 current = current->next;
649 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
654 copy_func ((GCObject**)&array, queue);
655 current->array = array;
657 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", array);
659 cur = mono_array_addr (array, Ephemeron, 0);
660 array_end = cur + mono_array_length_fast (array);
661 tombstone = SGEN_LOAD_VTABLE ((GCObject*)array)->domain->ephemeron_tombstone;
663 for (; cur < array_end; ++cur) {
664 GCObject *key = cur->key;
666 if (!key || key == tombstone)
669 SGEN_LOG (5, "[%zd] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
670 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
671 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
673 if (!sgen_is_object_alive_for_current_gen (key)) {
674 cur->key = tombstone;
680 current = current->next;
685 LOCKING: requires that the GC lock is held
687 Limitations: We scan all ephemerons on every collection since the current design doesn't allow for a simple nursery/mature split.
690 sgen_client_mark_ephemerons (ScanCopyContext ctx)
692 CopyOrMarkObjectFunc copy_func = ctx.ops->copy_or_mark_object;
693 SgenGrayQueue *queue = ctx.queue;
694 gboolean nothing_marked = TRUE;
695 EphemeronLinkNode *current = ephemeron_list;
696 Ephemeron *cur, *array_end;
699 for (current = ephemeron_list; current; current = current->next) {
700 MonoArray *array = current->array;
701 SGEN_LOG (5, "Ephemeron array at %p", array);
703 /*It has to be alive*/
704 if (!sgen_is_object_alive_for_current_gen ((GCObject*)array)) {
705 SGEN_LOG (5, "\tnot reachable");
709 copy_func ((GCObject**)&array, queue);
711 cur = mono_array_addr (array, Ephemeron, 0);
712 array_end = cur + mono_array_length_fast (array);
713 tombstone = SGEN_LOAD_VTABLE ((GCObject*)array)->domain->ephemeron_tombstone;
715 for (; cur < array_end; ++cur) {
716 GCObject *key = cur->key;
718 if (!key || key == tombstone)
721 SGEN_LOG (5, "[%zd] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
722 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
723 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
725 if (sgen_is_object_alive_for_current_gen (key)) {
726 GCObject *value = cur->value;
728 copy_func (&cur->key, queue);
730 if (!sgen_is_object_alive_for_current_gen (value))
731 nothing_marked = FALSE;
732 copy_func (&cur->value, queue);
738 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
739 return nothing_marked;
743 mono_gc_ephemeron_array_add (MonoObject *obj)
745 EphemeronLinkNode *node;
749 node = (EphemeronLinkNode *)sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
754 node->array = (MonoArray*)obj;
755 node->next = ephemeron_list;
756 ephemeron_list = node;
758 SGEN_LOG (5, "Registered ephemeron array %p", obj);
769 need_remove_object_for_domain (GCObject *start, MonoDomain *domain)
771 if (mono_object_domain (start) == domain) {
772 SGEN_LOG (4, "Need to cleanup object %p", start);
773 binary_protocol_cleanup (start, (gpointer)SGEN_LOAD_VTABLE (start), sgen_safe_object_get_size ((GCObject*)start));
780 process_object_for_domain_clearing (GCObject *start, MonoDomain *domain)
782 MonoVTable *vt = SGEN_LOAD_VTABLE (start);
783 if (vt->klass == mono_defaults.internal_thread_class)
784 g_assert (mono_object_domain (start) == mono_get_root_domain ());
785 /* The object could be a proxy for an object in the domain
787 #ifndef DISABLE_REMOTING
788 if (mono_defaults.real_proxy_class->supertypes && mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
789 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
791 /* The server could already have been zeroed out, so
792 we need to check for that, too. */
793 if (server && (!SGEN_LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
794 SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
795 ((MonoRealProxy*)start)->unwrapped_server = NULL;
802 clear_domain_process_object (GCObject *obj, MonoDomain *domain)
806 process_object_for_domain_clearing (obj, domain);
807 remove = need_remove_object_for_domain (obj, domain);
809 if (remove && obj->synchronisation) {
810 guint32 dislink = mono_monitor_get_object_monitor_gchandle (obj);
812 mono_gchandle_free (dislink);
819 clear_domain_process_minor_object_callback (GCObject *obj, size_t size, MonoDomain *domain)
821 if (clear_domain_process_object (obj, domain)) {
822 CANARIFY_SIZE (size);
823 memset (obj, 0, size);
828 clear_domain_process_major_object_callback (GCObject *obj, size_t size, MonoDomain *domain)
830 clear_domain_process_object (obj, domain);
834 clear_domain_free_major_non_pinned_object_callback (GCObject *obj, size_t size, MonoDomain *domain)
836 if (need_remove_object_for_domain (obj, domain))
837 major_collector.free_non_pinned_object (obj, size);
841 clear_domain_free_major_pinned_object_callback (GCObject *obj, size_t size, MonoDomain *domain)
843 if (need_remove_object_for_domain (obj, domain))
844 major_collector.free_pinned_object (obj, size);
848 * When appdomains are unloaded we can easily remove objects that have finalizers,
849 * but all the others could still be present in random places on the heap.
850 * We need a sweep to get rid of them even though it's going to be costly
852 * The reason we need to remove them is because we access the vtable and class
853 * structures to know the object size and the reference bitmap: once the domain is
854 * unloaded the point to random memory.
857 mono_gc_clear_domain (MonoDomain * domain)
859 LOSObject *bigobj, *prev;
864 binary_protocol_domain_unload_begin (domain);
868 if (sgen_concurrent_collection_in_progress ())
869 sgen_perform_collection (0, GENERATION_OLD, "clear domain", TRUE, FALSE);
870 SGEN_ASSERT (0, !sgen_concurrent_collection_in_progress (), "We just ordered a synchronous collection. Why are we collecting concurrently?");
872 major_collector.finish_sweeping ();
874 sgen_process_fin_stage_entries ();
876 sgen_clear_nursery_fragments ();
878 if (sgen_mono_xdomain_checks && domain != mono_get_root_domain ()) {
879 sgen_scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
880 sgen_scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
881 sgen_check_for_xdomain_refs ();
884 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
885 to memory returned to the OS.*/
886 null_ephemerons_for_domain (domain);
887 sgen_null_links_for_domain (domain);
889 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
890 sgen_remove_finalizers_if (object_in_domain_predicate, domain, i);
892 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
893 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE, TRUE);
895 /* We need two passes over major and large objects because
896 freeing such objects might give their memory back to the OS
897 (in the case of large objects) or obliterate its vtable
898 (pinned objects with major-copying or pinned and non-pinned
899 objects with major-mark&sweep), but we might need to
900 dereference a pointer from an object to another object if
901 the first object is a proxy. */
902 major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_ALL, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
903 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
904 clear_domain_process_object ((GCObject*)bigobj->data, domain);
907 for (bigobj = los_object_list; bigobj;) {
908 if (need_remove_object_for_domain ((GCObject*)bigobj->data, domain)) {
909 LOSObject *to_free = bigobj;
911 prev->next = bigobj->next;
913 los_object_list = bigobj->next;
914 bigobj = bigobj->next;
915 SGEN_LOG (4, "Freeing large object %p", bigobj->data);
916 sgen_los_free_object (to_free);
920 bigobj = bigobj->next;
922 major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_NON_PINNED, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
923 major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_PINNED, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
925 if (domain == mono_get_root_domain ()) {
926 sgen_pin_stats_report ();
927 sgen_object_layout_dump (stdout);
930 sgen_restart_world (0);
932 binary_protocol_domain_unload_end (domain);
933 binary_protocol_flush_buffers (FALSE);
943 mono_gc_alloc_obj (MonoVTable *vtable, size_t size)
945 MonoObject *obj = sgen_alloc_obj (vtable, size);
947 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_ALLOCATIONS)) {
949 mono_profiler_allocation (obj);
956 mono_gc_alloc_pinned_obj (MonoVTable *vtable, size_t size)
958 MonoObject *obj = sgen_alloc_obj_pinned (vtable, size);
960 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_ALLOCATIONS)) {
962 mono_profiler_allocation (obj);
969 mono_gc_alloc_mature (MonoVTable *vtable, size_t size)
971 MonoObject *obj = sgen_alloc_obj_mature (vtable, size);
973 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_ALLOCATIONS)) {
975 mono_profiler_allocation (obj);
982 mono_gc_alloc_fixed (size_t size, MonoGCDescriptor descr, MonoGCRootSource source, const char *msg)
984 /* FIXME: do a single allocation */
985 void *res = g_calloc (1, size);
988 if (!mono_gc_register_root ((char *)res, size, descr, source, msg)) {
996 mono_gc_free_fixed (void* addr)
998 mono_gc_deregister_root ((char *)addr);
1006 static MonoMethod* alloc_method_cache [ATYPE_NUM];
1007 static MonoMethod* slowpath_alloc_method_cache [ATYPE_NUM];
1008 static gboolean use_managed_allocator = TRUE;
1010 #ifdef MANAGED_ALLOCATION
1011 // Cache the SgenThreadInfo pointer in a local 'var'.
1012 #define EMIT_TLS_ACCESS_VAR(mb, var) \
1014 var = mono_mb_add_local ((mb), &mono_defaults.int_class->byval_arg); \
1015 mono_mb_emit_byte ((mb), MONO_CUSTOM_PREFIX); \
1016 mono_mb_emit_byte ((mb), CEE_MONO_TLS); \
1017 mono_mb_emit_i4 ((mb), TLS_KEY_SGEN_THREAD_INFO); \
1018 mono_mb_emit_stloc ((mb), (var)); \
1021 #define EMIT_TLS_ACCESS_IN_CRITICAL_REGION_ADDR(mb, var) \
1023 mono_mb_emit_ldloc ((mb), (var)); \
1024 mono_mb_emit_icon ((mb), MONO_STRUCT_OFFSET (SgenClientThreadInfo, in_critical_region)); \
1025 mono_mb_emit_byte ((mb), CEE_ADD); \
1028 #define EMIT_TLS_ACCESS_NEXT_ADDR(mb, var) do { \
1029 mono_mb_emit_ldloc ((mb), (var)); \
1030 mono_mb_emit_icon ((mb), MONO_STRUCT_OFFSET (SgenThreadInfo, tlab_next)); \
1031 mono_mb_emit_byte ((mb), CEE_ADD); \
1034 #define EMIT_TLS_ACCESS_TEMP_END(mb, var) do { \
1035 mono_mb_emit_ldloc ((mb), (var)); \
1036 mono_mb_emit_icon ((mb), MONO_STRUCT_OFFSET (SgenThreadInfo, tlab_temp_end)); \
1037 mono_mb_emit_byte ((mb), CEE_ADD); \
1038 mono_mb_emit_byte ((mb), CEE_LDIND_I); \
1041 /* FIXME: Do this in the JIT, where specialized allocation sequences can be created
1042 * for each class. This is currently not easy to do, as it is hard to generate basic
1043 * blocks + branches, but it is easy with the linear IL codebase.
1045 * For this to work we'd need to solve the TLAB race, first. Now we
1046 * require the allocator to be in a few known methods to make sure
1047 * that they are executed atomically via the restart mechanism.
1050 create_allocator (int atype, ManagedAllocatorVariant variant)
1052 int p_var, size_var, real_size_var, thread_var G_GNUC_UNUSED;
1053 gboolean slowpath = variant == MANAGED_ALLOCATOR_SLOW_PATH;
1054 guint32 slowpath_branch, max_size_branch;
1055 MonoMethodBuilder *mb;
1057 MonoMethodSignature *csig;
1058 static gboolean registered = FALSE;
1059 int tlab_next_addr_var, new_next_var;
1060 const char *name = NULL;
1065 mono_register_jit_icall (mono_gc_alloc_obj, "mono_gc_alloc_obj", mono_create_icall_signature ("object ptr int"), FALSE);
1066 mono_register_jit_icall (mono_gc_alloc_vector, "mono_gc_alloc_vector", mono_create_icall_signature ("object ptr int int"), FALSE);
1067 mono_register_jit_icall (mono_gc_alloc_string, "mono_gc_alloc_string", mono_create_icall_signature ("object ptr int int32"), FALSE);
1071 if (atype == ATYPE_SMALL) {
1072 name = slowpath ? "SlowAllocSmall" : "AllocSmall";
1073 } else if (atype == ATYPE_NORMAL) {
1074 name = slowpath ? "SlowAlloc" : "Alloc";
1075 } else if (atype == ATYPE_VECTOR) {
1076 name = slowpath ? "SlowAllocVector" : "AllocVector";
1077 } else if (atype == ATYPE_STRING) {
1078 name = slowpath ? "SlowAllocString" : "AllocString";
1080 g_assert_not_reached ();
1083 if (atype == ATYPE_NORMAL)
1088 csig = mono_metadata_signature_alloc (mono_defaults.corlib, num_params);
1089 if (atype == ATYPE_STRING) {
1090 csig->ret = &mono_defaults.string_class->byval_arg;
1091 csig->params [0] = &mono_defaults.int_class->byval_arg;
1092 csig->params [1] = &mono_defaults.int32_class->byval_arg;
1094 csig->ret = &mono_defaults.object_class->byval_arg;
1095 for (i = 0; i < num_params; i++)
1096 csig->params [i] = &mono_defaults.int_class->byval_arg;
1099 mb = mono_mb_new (mono_defaults.object_class, name, MONO_WRAPPER_ALLOC);
1106 mono_mb_emit_ldarg (mb, 0);
1107 mono_mb_emit_icall (mb, ves_icall_object_new_specific);
1110 mono_mb_emit_ldarg (mb, 0);
1111 mono_mb_emit_ldarg (mb, 1);
1112 mono_mb_emit_icall (mb, ves_icall_array_new_specific);
1115 mono_mb_emit_ldarg (mb, 1);
1116 mono_mb_emit_icall (mb, ves_icall_string_alloc);
1119 g_assert_not_reached ();
1126 * Tls access might call foreign code or code without jinfo. This can
1127 * only happen if we are outside of the critical region.
1129 EMIT_TLS_ACCESS_VAR (mb, thread_var);
1131 size_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
1132 if (atype == ATYPE_SMALL) {
1133 /* size_var = size_arg */
1134 mono_mb_emit_ldarg (mb, 1);
1135 mono_mb_emit_stloc (mb, size_var);
1136 } else if (atype == ATYPE_NORMAL) {
1137 /* size = vtable->klass->instance_size; */
1138 mono_mb_emit_ldarg (mb, 0);
1139 mono_mb_emit_icon (mb, MONO_STRUCT_OFFSET (MonoVTable, klass));
1140 mono_mb_emit_byte (mb, CEE_ADD);
1141 mono_mb_emit_byte (mb, CEE_LDIND_I);
1142 mono_mb_emit_icon (mb, MONO_STRUCT_OFFSET (MonoClass, instance_size));
1143 mono_mb_emit_byte (mb, CEE_ADD);
1144 /* FIXME: assert instance_size stays a 4 byte integer */
1145 mono_mb_emit_byte (mb, CEE_LDIND_U4);
1146 mono_mb_emit_byte (mb, CEE_CONV_I);
1147 mono_mb_emit_stloc (mb, size_var);
1148 } else if (atype == ATYPE_VECTOR) {
1149 MonoExceptionClause *clause;
1150 int pos, pos_leave, pos_error;
1151 MonoClass *oom_exc_class;
1155 * n > MONO_ARRAY_MAX_INDEX => OutOfMemoryException
1156 * n < 0 => OverflowException
1158 * We can do an unsigned comparison to catch both cases, then in the error
1159 * case compare signed to distinguish between them.
1161 mono_mb_emit_ldarg (mb, 1);
1162 mono_mb_emit_icon (mb, MONO_ARRAY_MAX_INDEX);
1163 mono_mb_emit_byte (mb, CEE_CONV_U);
1164 pos = mono_mb_emit_short_branch (mb, CEE_BLE_UN_S);
1166 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
1167 mono_mb_emit_byte (mb, CEE_MONO_NOT_TAKEN);
1168 mono_mb_emit_ldarg (mb, 1);
1169 mono_mb_emit_icon (mb, 0);
1170 pos_error = mono_mb_emit_short_branch (mb, CEE_BLT_S);
1171 mono_mb_emit_exception (mb, "OutOfMemoryException", NULL);
1172 mono_mb_patch_short_branch (mb, pos_error);
1173 mono_mb_emit_exception (mb, "OverflowException", NULL);
1175 mono_mb_patch_short_branch (mb, pos);
1177 clause = (MonoExceptionClause *)mono_image_alloc0 (mono_defaults.corlib, sizeof (MonoExceptionClause));
1178 clause->try_offset = mono_mb_get_label (mb);
1180 /* vtable->klass->sizes.element_size */
1181 mono_mb_emit_ldarg (mb, 0);
1182 mono_mb_emit_icon (mb, MONO_STRUCT_OFFSET (MonoVTable, klass));
1183 mono_mb_emit_byte (mb, CEE_ADD);
1184 mono_mb_emit_byte (mb, CEE_LDIND_I);
1185 mono_mb_emit_icon (mb, MONO_STRUCT_OFFSET (MonoClass, sizes));
1186 mono_mb_emit_byte (mb, CEE_ADD);
1187 mono_mb_emit_byte (mb, CEE_LDIND_U4);
1188 mono_mb_emit_byte (mb, CEE_CONV_I);
1191 mono_mb_emit_ldarg (mb, 1);
1192 mono_mb_emit_byte (mb, CEE_MUL_OVF_UN);
1193 /* + sizeof (MonoArray) */
1194 mono_mb_emit_icon (mb, MONO_SIZEOF_MONO_ARRAY);
1195 mono_mb_emit_byte (mb, CEE_ADD_OVF_UN);
1196 mono_mb_emit_stloc (mb, size_var);
1198 pos_leave = mono_mb_emit_branch (mb, CEE_LEAVE);
1201 clause->flags = MONO_EXCEPTION_CLAUSE_NONE;
1202 clause->try_len = mono_mb_get_pos (mb) - clause->try_offset;
1203 clause->data.catch_class = mono_class_load_from_name (mono_defaults.corlib,
1204 "System", "OverflowException");
1205 clause->handler_offset = mono_mb_get_label (mb);
1207 oom_exc_class = mono_class_load_from_name (mono_defaults.corlib,
1208 "System", "OutOfMemoryException");
1209 ctor = mono_class_get_method_from_name (oom_exc_class, ".ctor", 0);
1212 mono_mb_emit_byte (mb, CEE_POP);
1213 mono_mb_emit_op (mb, CEE_NEWOBJ, ctor);
1214 mono_mb_emit_byte (mb, CEE_THROW);
1216 clause->handler_len = mono_mb_get_pos (mb) - clause->handler_offset;
1217 mono_mb_set_clauses (mb, 1, clause);
1218 mono_mb_patch_branch (mb, pos_leave);
1220 } else if (atype == ATYPE_STRING) {
1224 * a string allocator method takes the args: (vtable, len)
1226 * bytes = offsetof (MonoString, chars) + ((len + 1) * 2)
1230 * bytes <= INT32_MAX - (SGEN_ALLOC_ALIGN - 1)
1234 * offsetof (MonoString, chars) + ((len + 1) * 2) <= INT32_MAX - (SGEN_ALLOC_ALIGN - 1)
1235 * len <= (INT32_MAX - (SGEN_ALLOC_ALIGN - 1) - offsetof (MonoString, chars)) / 2 - 1
1237 mono_mb_emit_ldarg (mb, 1);
1238 mono_mb_emit_icon (mb, (INT32_MAX - (SGEN_ALLOC_ALIGN - 1) - MONO_STRUCT_OFFSET (MonoString, chars)) / 2 - 1);
1239 pos = mono_mb_emit_short_branch (mb, MONO_CEE_BLE_UN_S);
1241 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
1242 mono_mb_emit_byte (mb, CEE_MONO_NOT_TAKEN);
1243 mono_mb_emit_exception (mb, "OutOfMemoryException", NULL);
1244 mono_mb_patch_short_branch (mb, pos);
1246 mono_mb_emit_ldarg (mb, 1);
1247 mono_mb_emit_icon (mb, 1);
1248 mono_mb_emit_byte (mb, MONO_CEE_SHL);
1249 //WE manually fold the above + 2 here
1250 mono_mb_emit_icon (mb, MONO_STRUCT_OFFSET (MonoString, chars) + 2);
1251 mono_mb_emit_byte (mb, CEE_ADD);
1252 mono_mb_emit_stloc (mb, size_var);
1254 g_assert_not_reached ();
1257 #ifdef MANAGED_ALLOCATOR_CAN_USE_CRITICAL_REGION
1258 EMIT_TLS_ACCESS_IN_CRITICAL_REGION_ADDR (mb, thread_var);
1259 mono_mb_emit_byte (mb, CEE_LDC_I4_1);
1260 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
1261 mono_mb_emit_byte (mb, CEE_MONO_ATOMIC_STORE_I4);
1262 mono_mb_emit_i4 (mb, MONO_MEMORY_BARRIER_NONE);
1265 if (nursery_canaries_enabled ()) {
1266 real_size_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
1267 mono_mb_emit_ldloc (mb, size_var);
1268 mono_mb_emit_stloc(mb, real_size_var);
1271 real_size_var = size_var;
1273 /* size += ALLOC_ALIGN - 1; */
1274 mono_mb_emit_ldloc (mb, size_var);
1275 mono_mb_emit_icon (mb, SGEN_ALLOC_ALIGN - 1);
1276 mono_mb_emit_byte (mb, CEE_ADD);
1277 /* size &= ~(ALLOC_ALIGN - 1); */
1278 mono_mb_emit_icon (mb, ~(SGEN_ALLOC_ALIGN - 1));
1279 mono_mb_emit_byte (mb, CEE_AND);
1280 mono_mb_emit_stloc (mb, size_var);
1282 /* if (size > MAX_SMALL_OBJ_SIZE) goto slowpath */
1283 if (atype != ATYPE_SMALL) {
1284 mono_mb_emit_ldloc (mb, size_var);
1285 mono_mb_emit_icon (mb, SGEN_MAX_SMALL_OBJ_SIZE);
1286 max_size_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S);
1290 * We need to modify tlab_next, but the JIT only supports reading, so we read
1291 * another tls var holding its address instead.
1294 /* tlab_next_addr (local) = tlab_next_addr (TLS var) */
1295 tlab_next_addr_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
1296 EMIT_TLS_ACCESS_NEXT_ADDR (mb, thread_var);
1297 mono_mb_emit_stloc (mb, tlab_next_addr_var);
1299 /* p = (void**)tlab_next; */
1300 p_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
1301 mono_mb_emit_ldloc (mb, tlab_next_addr_var);
1302 mono_mb_emit_byte (mb, CEE_LDIND_I);
1303 mono_mb_emit_stloc (mb, p_var);
1305 /* new_next = (char*)p + size; */
1306 new_next_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
1307 mono_mb_emit_ldloc (mb, p_var);
1308 mono_mb_emit_ldloc (mb, size_var);
1309 mono_mb_emit_byte (mb, CEE_CONV_I);
1310 mono_mb_emit_byte (mb, CEE_ADD);
1312 if (nursery_canaries_enabled ()) {
1313 mono_mb_emit_icon (mb, CANARY_SIZE);
1314 mono_mb_emit_byte (mb, CEE_ADD);
1316 mono_mb_emit_stloc (mb, new_next_var);
1318 /* if (G_LIKELY (new_next < tlab_temp_end)) */
1319 mono_mb_emit_ldloc (mb, new_next_var);
1320 EMIT_TLS_ACCESS_TEMP_END (mb, thread_var);
1321 slowpath_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
1324 if (atype != ATYPE_SMALL)
1325 mono_mb_patch_short_branch (mb, max_size_branch);
1327 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
1328 mono_mb_emit_byte (mb, CEE_MONO_NOT_TAKEN);
1330 * We are no longer in a critical section. We need to do this before calling
1331 * to unmanaged land in order to avoid stw deadlocks since unmanaged code
1334 #ifdef MANAGED_ALLOCATOR_CAN_USE_CRITICAL_REGION
1335 EMIT_TLS_ACCESS_IN_CRITICAL_REGION_ADDR (mb, thread_var);
1336 mono_mb_emit_byte (mb, CEE_LDC_I4_0);
1337 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
1338 mono_mb_emit_byte (mb, CEE_MONO_ATOMIC_STORE_I4);
1339 mono_mb_emit_i4 (mb, MONO_MEMORY_BARRIER_NONE);
1342 /* FIXME: mono_gc_alloc_obj takes a 'size_t' as an argument, not an int32 */
1343 mono_mb_emit_ldarg (mb, 0);
1344 mono_mb_emit_ldloc (mb, real_size_var);
1345 if (atype == ATYPE_NORMAL || atype == ATYPE_SMALL) {
1346 mono_mb_emit_icall (mb, mono_gc_alloc_obj);
1347 } else if (atype == ATYPE_VECTOR) {
1348 mono_mb_emit_ldarg (mb, 1);
1349 mono_mb_emit_icall (mb, mono_gc_alloc_vector);
1350 } else if (atype == ATYPE_STRING) {
1351 mono_mb_emit_ldarg (mb, 1);
1352 mono_mb_emit_icall (mb, mono_gc_alloc_string);
1354 g_assert_not_reached ();
1356 mono_mb_emit_byte (mb, CEE_RET);
1359 mono_mb_patch_short_branch (mb, slowpath_branch);
1361 /* FIXME: Memory barrier */
1363 /* tlab_next = new_next */
1364 mono_mb_emit_ldloc (mb, tlab_next_addr_var);
1365 mono_mb_emit_ldloc (mb, new_next_var);
1366 mono_mb_emit_byte (mb, CEE_STIND_I);
1369 mono_mb_emit_ldloc (mb, p_var);
1370 mono_mb_emit_ldarg (mb, 0);
1371 mono_mb_emit_byte (mb, CEE_STIND_I);
1373 /* mark object end with nursery word */
1374 if (nursery_canaries_enabled ()) {
1375 mono_mb_emit_ldloc (mb, p_var);
1376 mono_mb_emit_ldloc (mb, real_size_var);
1377 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1378 mono_mb_emit_icon8 (mb, (mword) CANARY_STRING);
1379 mono_mb_emit_icon (mb, CANARY_SIZE);
1380 mono_mb_emit_byte (mb, MONO_CEE_PREFIX1);
1381 mono_mb_emit_byte (mb, CEE_CPBLK);
1384 if (atype == ATYPE_VECTOR) {
1385 /* arr->max_length = max_length; */
1386 mono_mb_emit_ldloc (mb, p_var);
1387 mono_mb_emit_ldflda (mb, MONO_STRUCT_OFFSET (MonoArray, max_length));
1388 mono_mb_emit_ldarg (mb, 1);
1389 #ifdef MONO_BIG_ARRAYS
1390 mono_mb_emit_byte (mb, CEE_STIND_I);
1392 mono_mb_emit_byte (mb, CEE_STIND_I4);
1394 } else if (atype == ATYPE_STRING) {
1395 /* need to set length and clear the last char */
1396 /* s->length = len; */
1397 mono_mb_emit_ldloc (mb, p_var);
1398 mono_mb_emit_icon (mb, MONO_STRUCT_OFFSET (MonoString, length));
1399 mono_mb_emit_byte (mb, MONO_CEE_ADD);
1400 mono_mb_emit_ldarg (mb, 1);
1401 mono_mb_emit_byte (mb, MONO_CEE_STIND_I4);
1404 #ifdef MANAGED_ALLOCATOR_CAN_USE_CRITICAL_REGION
1405 EMIT_TLS_ACCESS_IN_CRITICAL_REGION_ADDR (mb, thread_var);
1406 mono_mb_emit_byte (mb, CEE_LDC_I4_0);
1407 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
1408 mono_mb_emit_byte (mb, CEE_MONO_ATOMIC_STORE_I4);
1410 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
1411 mono_mb_emit_byte (mb, CEE_MONO_MEMORY_BARRIER);
1414 We must make sure both vtable and max_length are globaly visible before returning to managed land.
1416 mono_mb_emit_i4 (mb, MONO_MEMORY_BARRIER_REL);
1419 mono_mb_emit_ldloc (mb, p_var);
1422 mono_mb_emit_byte (mb, CEE_RET);
1425 info = mono_wrapper_info_create (mb, WRAPPER_SUBTYPE_NONE);
1426 info->d.alloc.gc_name = "sgen";
1427 info->d.alloc.alloc_type = atype;
1430 mb->init_locals = FALSE;
1433 res = mono_mb_create (mb, csig, 8, info);
1442 mono_gc_get_aligned_size_for_allocator (int size)
1444 return SGEN_ALIGN_UP (size);
1448 * Generate an allocator method implementing the fast path of mono_gc_alloc_obj ().
1449 * The signature of the called method is:
1450 * object allocate (MonoVTable *vtable)
1453 mono_gc_get_managed_allocator (MonoClass *klass, gboolean for_box, gboolean known_instance_size)
1455 #ifdef MANAGED_ALLOCATION
1456 if (collect_before_allocs)
1458 if (klass->instance_size > tlab_size)
1460 if (known_instance_size && ALIGN_TO (klass->instance_size, SGEN_ALLOC_ALIGN) >= SGEN_MAX_SMALL_OBJ_SIZE)
1462 if (mono_class_has_finalizer (klass) || mono_class_is_marshalbyref (klass))
1466 if (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS)
1468 if (klass->byval_arg.type == MONO_TYPE_STRING)
1469 return mono_gc_get_managed_allocator_by_type (ATYPE_STRING, MANAGED_ALLOCATOR_REGULAR);
1470 /* Generic classes have dynamic field and can go above MAX_SMALL_OBJ_SIZE. */
1471 if (known_instance_size)
1472 return mono_gc_get_managed_allocator_by_type (ATYPE_SMALL, MANAGED_ALLOCATOR_REGULAR);
1474 return mono_gc_get_managed_allocator_by_type (ATYPE_NORMAL, MANAGED_ALLOCATOR_REGULAR);
1481 mono_gc_get_managed_array_allocator (MonoClass *klass)
1483 #ifdef MANAGED_ALLOCATION
1484 if (klass->rank != 1)
1486 if (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS)
1488 if (has_per_allocation_action)
1490 g_assert (!mono_class_has_finalizer (klass) && !mono_class_is_marshalbyref (klass));
1492 return mono_gc_get_managed_allocator_by_type (ATYPE_VECTOR, MANAGED_ALLOCATOR_REGULAR);
1499 sgen_set_use_managed_allocator (gboolean flag)
1501 use_managed_allocator = flag;
1505 mono_gc_get_managed_allocator_by_type (int atype, ManagedAllocatorVariant variant)
1507 #ifdef MANAGED_ALLOCATION
1511 if (variant == MANAGED_ALLOCATOR_REGULAR && !use_managed_allocator)
1515 case MANAGED_ALLOCATOR_REGULAR: cache = alloc_method_cache; break;
1516 case MANAGED_ALLOCATOR_SLOW_PATH: cache = slowpath_alloc_method_cache; break;
1517 default: g_assert_not_reached (); break;
1520 res = cache [atype];
1524 res = create_allocator (atype, variant);
1526 if (cache [atype]) {
1527 mono_free_method (res);
1528 res = cache [atype];
1530 mono_memory_barrier ();
1531 cache [atype] = res;
1542 mono_gc_get_managed_allocator_types (void)
1548 sgen_is_managed_allocator (MonoMethod *method)
1552 for (i = 0; i < ATYPE_NUM; ++i)
1553 if (method == alloc_method_cache [i] || method == slowpath_alloc_method_cache [i])
1559 sgen_has_managed_allocator (void)
1563 for (i = 0; i < ATYPE_NUM; ++i)
1564 if (alloc_method_cache [i] || slowpath_alloc_method_cache [i])
1570 * Cardtable scanning
1573 #define MWORD_MASK (sizeof (mword) - 1)
1576 find_card_offset (mword card)
1578 /*XXX Use assembly as this generates some pretty bad code */
1579 #if defined(__i386__) && defined(__GNUC__)
1580 return (__builtin_ffs (card) - 1) / 8;
1581 #elif defined(__x86_64__) && defined(__GNUC__)
1582 return (__builtin_ffsll (card) - 1) / 8;
1583 #elif defined(__s390x__)
1584 return (__builtin_ffsll (GUINT64_TO_LE(card)) - 1) / 8;
1587 guint8 *ptr = (guint8 *) &card;
1588 for (i = 0; i < sizeof (mword); ++i) {
1597 find_next_card (guint8 *card_data, guint8 *end)
1599 mword *cards, *cards_end;
1602 while ((((mword)card_data) & MWORD_MASK) && card_data < end) {
1608 if (card_data == end)
1611 cards = (mword*)card_data;
1612 cards_end = (mword*)((mword)end & ~MWORD_MASK);
1613 while (cards < cards_end) {
1616 return (guint8*)cards + find_card_offset (card);
1620 card_data = (guint8*)cards_end;
1621 while (card_data < end) {
1630 #define ARRAY_OBJ_INDEX(ptr,array,elem_size) (((char*)(ptr) - ((char*)(array) + G_STRUCT_OFFSET (MonoArray, vector))) / (elem_size))
1633 sgen_client_cardtable_scan_object (GCObject *obj, guint8 *cards, ScanCopyContext ctx)
1635 MonoVTable *vt = SGEN_LOAD_VTABLE (obj);
1636 MonoClass *klass = vt->klass;
1638 SGEN_ASSERT (0, SGEN_VTABLE_HAS_REFERENCES (vt), "Why would we ever call this on reference-free objects?");
1641 MonoArray *arr = (MonoArray*)obj;
1642 guint8 *card_data, *card_base;
1643 guint8 *card_data_end;
1644 char *obj_start = (char *)sgen_card_table_align_pointer (obj);
1646 mword obj_size = sgen_mono_array_size (vt, arr, &bounds_size, sgen_vtable_get_descriptor (vt));
1647 /* We don't want to scan the bounds entries at the end of multidimensional arrays */
1648 char *obj_end = (char*)obj + obj_size - bounds_size;
1650 size_t extra_idx = 0;
1652 mword desc = (mword)klass->element_class->gc_descr;
1653 int elem_size = mono_array_element_size (klass);
1655 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
1656 guint8 *overflow_scan_end = NULL;
1659 #ifdef SGEN_OBJECT_LAYOUT_STATISTICS
1660 if (klass->element_class->valuetype)
1661 sgen_object_layout_scanned_vtype_array ();
1663 sgen_object_layout_scanned_ref_array ();
1669 card_data = sgen_card_table_get_card_scan_address ((mword)obj);
1671 card_base = card_data;
1672 card_count = sgen_card_table_number_of_cards_in_range ((mword)obj, obj_size);
1673 card_data_end = card_data + card_count;
1676 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
1677 /*Check for overflow and if so, setup to scan in two steps*/
1678 if (!cards && card_data_end >= SGEN_SHADOW_CARDTABLE_END) {
1679 overflow_scan_end = sgen_shadow_cardtable + (card_data_end - SGEN_SHADOW_CARDTABLE_END);
1680 card_data_end = SGEN_SHADOW_CARDTABLE_END;
1686 card_data = find_next_card (card_data, card_data_end);
1687 for (; card_data < card_data_end; card_data = find_next_card (card_data + 1, card_data_end)) {
1689 size_t idx = (card_data - card_base) + extra_idx;
1690 char *start = (char*)(obj_start + idx * CARD_SIZE_IN_BYTES);
1691 char *card_end = start + CARD_SIZE_IN_BYTES;
1692 char *first_elem, *elem;
1694 HEAVY_STAT (++los_marked_cards);
1697 sgen_card_table_prepare_card_for_scanning (card_data);
1699 card_end = MIN (card_end, obj_end);
1701 if (start <= (char*)arr->vector)
1704 index = ARRAY_OBJ_INDEX (start, obj, elem_size);
1706 elem = first_elem = (char*)mono_array_addr_with_size_fast ((MonoArray*)obj, elem_size, index);
1707 if (klass->element_class->valuetype) {
1708 ScanVTypeFunc scan_vtype_func = ctx.ops->scan_vtype;
1710 for (; elem < card_end; elem += elem_size)
1711 scan_vtype_func (obj, elem, desc, ctx.queue BINARY_PROTOCOL_ARG (elem_size));
1713 ScanPtrFieldFunc scan_ptr_field_func = ctx.ops->scan_ptr_field;
1715 HEAVY_STAT (++los_array_cards);
1716 for (; elem < card_end; elem += SIZEOF_VOID_P)
1717 scan_ptr_field_func (obj, (GCObject**)elem, ctx.queue);
1720 binary_protocol_card_scan (first_elem, elem - first_elem);
1723 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
1724 if (overflow_scan_end) {
1725 extra_idx = card_data - card_base;
1726 card_base = card_data = sgen_shadow_cardtable;
1727 card_data_end = overflow_scan_end;
1728 overflow_scan_end = NULL;
1739 * Array and string allocation
1743 mono_gc_alloc_vector (MonoVTable *vtable, size_t size, uintptr_t max_length)
1748 if (!SGEN_CAN_ALIGN_UP (size))
1751 #ifndef DISABLE_CRITICAL_REGION
1752 ENTER_CRITICAL_REGION;
1753 arr = (MonoArray*)sgen_try_alloc_obj_nolock (vtable, size);
1755 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
1756 arr->max_length = (mono_array_size_t)max_length;
1757 EXIT_CRITICAL_REGION;
1760 EXIT_CRITICAL_REGION;
1765 arr = (MonoArray*)sgen_alloc_obj_nolock (vtable, size);
1766 if (G_UNLIKELY (!arr)) {
1771 arr->max_length = (mono_array_size_t)max_length;
1776 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_ALLOCATIONS))
1777 mono_profiler_allocation (&arr->obj);
1779 SGEN_ASSERT (6, SGEN_ALIGN_UP (size) == SGEN_ALIGN_UP (sgen_client_par_object_get_size (vtable, (GCObject*)arr)), "Vector has incorrect size.");
1784 mono_gc_alloc_array (MonoVTable *vtable, size_t size, uintptr_t max_length, uintptr_t bounds_size)
1787 MonoArrayBounds *bounds;
1790 if (!SGEN_CAN_ALIGN_UP (size))
1793 #ifndef DISABLE_CRITICAL_REGION
1794 ENTER_CRITICAL_REGION;
1795 arr = (MonoArray*)sgen_try_alloc_obj_nolock (vtable, size);
1797 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
1798 arr->max_length = (mono_array_size_t)max_length;
1800 bounds = (MonoArrayBounds*)((char*)arr + size - bounds_size);
1801 arr->bounds = bounds;
1802 EXIT_CRITICAL_REGION;
1805 EXIT_CRITICAL_REGION;
1810 arr = (MonoArray*)sgen_alloc_obj_nolock (vtable, size);
1811 if (G_UNLIKELY (!arr)) {
1816 arr->max_length = (mono_array_size_t)max_length;
1818 bounds = (MonoArrayBounds*)((char*)arr + size - bounds_size);
1819 arr->bounds = bounds;
1824 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_ALLOCATIONS))
1825 mono_profiler_allocation (&arr->obj);
1827 SGEN_ASSERT (6, SGEN_ALIGN_UP (size) == SGEN_ALIGN_UP (sgen_client_par_object_get_size (vtable, (GCObject*)arr)), "Array has incorrect size.");
1832 mono_gc_alloc_string (MonoVTable *vtable, size_t size, gint32 len)
1837 if (!SGEN_CAN_ALIGN_UP (size))
1840 #ifndef DISABLE_CRITICAL_REGION
1841 ENTER_CRITICAL_REGION;
1842 str = (MonoString*)sgen_try_alloc_obj_nolock (vtable, size);
1844 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
1846 EXIT_CRITICAL_REGION;
1849 EXIT_CRITICAL_REGION;
1854 str = (MonoString*)sgen_alloc_obj_nolock (vtable, size);
1855 if (G_UNLIKELY (!str)) {
1865 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_ALLOCATIONS))
1866 mono_profiler_allocation (&str->object);
1876 mono_gc_set_string_length (MonoString *str, gint32 new_length)
1878 mono_unichar2 *new_end = str->chars + new_length;
1880 /* zero the discarded string. This null-delimits the string and allows
1881 * the space to be reclaimed by SGen. */
1883 if (nursery_canaries_enabled () && sgen_ptr_in_nursery (str)) {
1884 CHECK_CANARY_FOR_OBJECT ((GCObject*)str, TRUE);
1885 memset (new_end, 0, (str->length - new_length + 1) * sizeof (mono_unichar2) + CANARY_SIZE);
1886 memcpy (new_end + 1 , CANARY_STRING, CANARY_SIZE);
1888 memset (new_end, 0, (str->length - new_length + 1) * sizeof (mono_unichar2));
1891 str->length = new_length;
1898 #define GC_ROOT_NUM 32
1900 int count; /* must be the first field */
1901 void *objects [GC_ROOT_NUM];
1902 int root_types [GC_ROOT_NUM];
1903 uintptr_t extra_info [GC_ROOT_NUM];
1907 notify_gc_roots (GCRootReport *report)
1911 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
1916 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
1918 if (report->count == GC_ROOT_NUM)
1919 notify_gc_roots (report);
1920 report->objects [report->count] = object;
1921 report->root_types [report->count] = rtype;
1922 report->extra_info [report->count++] = (uintptr_t)SGEN_LOAD_VTABLE (object)->klass;
1926 sgen_client_nursery_objects_pinned (void **definitely_pinned, int count)
1928 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1929 GCRootReport report;
1932 for (idx = 0; idx < count; ++idx)
1933 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1934 notify_gc_roots (&report);
1939 report_finalizer_roots_from_queue (SgenPointerQueue *queue)
1941 GCRootReport report;
1945 for (i = 0; i < queue->next_slot; ++i) {
1946 void *obj = queue->data [i];
1949 add_profile_gc_root (&report, obj, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1951 notify_gc_roots (&report);
1955 report_finalizer_roots (SgenPointerQueue *fin_ready_queue, SgenPointerQueue *critical_fin_queue)
1957 report_finalizer_roots_from_queue (fin_ready_queue);
1958 report_finalizer_roots_from_queue (critical_fin_queue);
1961 static GCRootReport *root_report;
1964 single_arg_report_root (MonoObject **obj, void *gc_data)
1967 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1971 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1973 switch (desc & ROOT_DESC_TYPE_MASK) {
1974 case ROOT_DESC_BITMAP:
1975 desc >>= ROOT_DESC_TYPE_SHIFT;
1977 if ((desc & 1) && *start_root) {
1978 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1984 case ROOT_DESC_COMPLEX: {
1985 gsize *bitmap_data = (gsize *)sgen_get_complex_descriptor_bitmap (desc);
1986 gsize bwords = (*bitmap_data) - 1;
1987 void **start_run = start_root;
1989 while (bwords-- > 0) {
1990 gsize bmap = *bitmap_data++;
1991 void **objptr = start_run;
1993 if ((bmap & 1) && *objptr) {
1994 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1999 start_run += GC_BITS_PER_WORD;
2003 case ROOT_DESC_USER: {
2004 MonoGCRootMarkFunc marker = (MonoGCRootMarkFunc)sgen_get_user_descriptor_func (desc);
2005 root_report = report;
2006 marker ((MonoObject**)start_root, single_arg_report_root, NULL);
2009 case ROOT_DESC_RUN_LEN:
2010 g_assert_not_reached ();
2012 g_assert_not_reached ();
2017 report_registered_roots_by_type (int root_type)
2019 GCRootReport report;
2023 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], void **, start_root, RootRecord *, root) {
2024 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
2025 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
2026 } SGEN_HASH_TABLE_FOREACH_END;
2027 notify_gc_roots (&report);
2031 report_registered_roots (void)
2033 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
2034 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
2038 sgen_client_collecting_minor (SgenPointerQueue *fin_ready_queue, SgenPointerQueue *critical_fin_queue)
2040 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2041 report_registered_roots ();
2042 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2043 report_finalizer_roots (fin_ready_queue, critical_fin_queue);
2046 static GCRootReport major_root_report;
2047 static gboolean profile_roots;
2050 sgen_client_collecting_major_1 (void)
2052 profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2053 memset (&major_root_report, 0, sizeof (GCRootReport));
2057 sgen_client_pinned_los_object (GCObject *obj)
2060 add_profile_gc_root (&major_root_report, (char*)obj, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2064 sgen_client_collecting_major_2 (void)
2067 notify_gc_roots (&major_root_report);
2069 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2070 report_registered_roots ();
2074 sgen_client_collecting_major_3 (SgenPointerQueue *fin_ready_queue, SgenPointerQueue *critical_fin_queue)
2076 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2077 report_finalizer_roots (fin_ready_queue, critical_fin_queue);
2080 #define MOVED_OBJECTS_NUM 64
2081 static void *moved_objects [MOVED_OBJECTS_NUM];
2082 static int moved_objects_idx = 0;
2084 static SgenPointerQueue moved_objects_queue = SGEN_POINTER_QUEUE_INIT (INTERNAL_MEM_MOVED_OBJECT);
2087 mono_sgen_register_moved_object (void *obj, void *destination)
2090 * This function can be called from SGen's worker threads. We want to try
2091 * and avoid exposing those threads to the profiler API, so queue up move
2092 * events and send them later when the main GC thread calls
2093 * mono_sgen_gc_event_moves ().
2095 * TODO: Once SGen has multiple worker threads, we need to switch to a
2096 * lock-free data structure for the queue as multiple threads will be
2097 * adding to it at the same time.
2099 if (sgen_thread_pool_is_thread_pool_thread (mono_native_thread_id_get ())) {
2100 sgen_pointer_queue_add (&moved_objects_queue, obj);
2101 sgen_pointer_queue_add (&moved_objects_queue, destination);
2103 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2104 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2105 moved_objects_idx = 0;
2108 moved_objects [moved_objects_idx++] = obj;
2109 moved_objects [moved_objects_idx++] = destination;
2114 mono_sgen_gc_event_moves (void)
2116 while (!sgen_pointer_queue_is_empty (&moved_objects_queue)) {
2117 void *dst = sgen_pointer_queue_pop (&moved_objects_queue);
2118 void *src = sgen_pointer_queue_pop (&moved_objects_queue);
2120 mono_sgen_register_moved_object (src, dst);
2123 if (moved_objects_idx) {
2124 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2125 moved_objects_idx = 0;
2133 #define REFS_SIZE 128
2136 MonoGCReferences callback;
2140 MonoObject *refs [REFS_SIZE];
2141 uintptr_t offsets [REFS_SIZE];
2145 #define HANDLE_PTR(ptr,obj) do { \
2147 if (hwi->count == REFS_SIZE) { \
2148 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
2152 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
2153 hwi->refs [hwi->count++] = *(ptr); \
2158 collect_references (HeapWalkInfo *hwi, GCObject *obj, size_t size)
2160 char *start = (char*)obj;
2161 mword desc = sgen_obj_get_descriptor (obj);
2163 #include "sgen/sgen-scan-object.h"
2167 walk_references (GCObject *start, size_t size, void *data)
2169 HeapWalkInfo *hwi = (HeapWalkInfo *)data;
2172 collect_references (hwi, start, size);
2173 if (hwi->count || !hwi->called)
2174 hwi->callback (start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
2178 * mono_gc_walk_heap:
2179 * @flags: flags for future use
2180 * @callback: a function pointer called for each object in the heap
2181 * @data: a user data pointer that is passed to callback
2183 * This function can be used to iterate over all the live objects in the heap:
2184 * for each object, @callback is invoked, providing info about the object's
2185 * location in memory, its class, its size and the objects it references.
2186 * For each referenced object it's offset from the object address is
2187 * reported in the offsets array.
2188 * The object references may be buffered, so the callback may be invoked
2189 * multiple times for the same object: in all but the first call, the size
2190 * argument will be zero.
2191 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
2192 * profiler event handler.
2194 * Returns: a non-zero value if the GC doesn't support heap walking
2197 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
2202 hwi.callback = callback;
2205 sgen_clear_nursery_fragments ();
2206 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE, TRUE);
2208 major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_ALL, walk_references, &hwi);
2209 sgen_los_iterate_objects (walk_references, &hwi);
2219 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
2221 gc_callbacks = *callbacks;
2225 mono_gc_get_gc_callbacks ()
2227 return &gc_callbacks;
2231 sgen_client_thread_register (SgenThreadInfo* info, void *stack_bottom_fallback)
2234 guint8 *staddr = NULL;
2236 mono_tls_set_sgen_thread_info (info);
2238 info->client_info.skip = 0;
2240 info->client_info.stack_start = NULL;
2242 #ifdef SGEN_POSIX_STW
2243 info->client_info.stop_count = -1;
2244 info->client_info.signal = 0;
2247 mono_thread_info_get_stack_bounds (&staddr, &stsize);
2249 info->client_info.stack_start_limit = staddr;
2250 info->client_info.stack_end = staddr + stsize;
2252 gsize stack_bottom = (gsize)stack_bottom_fallback;
2253 stack_bottom += 4095;
2254 stack_bottom &= ~4095;
2255 info->client_info.stack_end = (char*)stack_bottom;
2258 memset (&info->client_info.ctx, 0, sizeof (MonoContext));
2260 if (mono_gc_get_gc_callbacks ()->thread_attach_func)
2261 info->client_info.runtime_data = mono_gc_get_gc_callbacks ()->thread_attach_func ();
2263 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
2265 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->client_info.stack_end);
2267 info->client_info.info.handle_stack = mono_handle_stack_alloc ();
2271 sgen_client_thread_unregister (SgenThreadInfo *p)
2273 MonoNativeThreadId tid;
2275 mono_tls_set_sgen_thread_info (NULL);
2277 tid = mono_thread_info_get_tid (p);
2279 if (p->client_info.info.runtime_thread)
2280 mono_threads_add_joinable_thread ((gpointer)tid);
2282 if (mono_gc_get_gc_callbacks ()->thread_detach_func) {
2283 mono_gc_get_gc_callbacks ()->thread_detach_func (p->client_info.runtime_data);
2284 p->client_info.runtime_data = NULL;
2287 binary_protocol_thread_unregister ((gpointer)tid);
2288 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)tid);
2290 HandleStack *handles = (HandleStack*) p->client_info.info.handle_stack;
2291 p->client_info.info.handle_stack = NULL;
2292 mono_handle_stack_free (handles);
2296 mono_gc_set_skip_thread (gboolean skip)
2298 SgenThreadInfo *info = mono_thread_info_current ();
2301 info->client_info.gc_disabled = skip;
2305 /* If we skip scanning a thread with a non-empty handle stack, we may move an
2306 * object but fail to update the reference in the handle.
2308 HandleStack *stack = info->client_info.info.handle_stack;
2309 g_assert (stack == NULL || mono_handle_stack_is_empty (stack));
2314 thread_in_critical_region (SgenThreadInfo *info)
2316 return info->client_info.in_critical_region;
2320 sgen_thread_attach (SgenThreadInfo *info)
2322 if (mono_gc_get_gc_callbacks ()->thread_attach_func && !info->client_info.runtime_data)
2323 info->client_info.runtime_data = mono_gc_get_gc_callbacks ()->thread_attach_func ();
2327 sgen_thread_detach (SgenThreadInfo *p)
2329 /* If a delegate is passed to native code and invoked on a thread we dont
2330 * know about, marshal will register it with mono_threads_attach_coop, but
2331 * we have no way of knowing when that thread goes away. SGen has a TSD
2332 * so we assume that if the domain is still registered, we can detach
2335 if (mono_thread_internal_current_is_attached ())
2336 mono_thread_detach_internal (mono_thread_internal_current ());
2340 mono_gc_register_thread (void *baseptr)
2342 return mono_thread_info_attach (baseptr) != NULL;
2346 mono_gc_is_gc_thread (void)
2350 result = mono_thread_info_current () != NULL;
2356 sgen_client_thread_register_worker (void)
2358 mono_thread_info_register_small_id ();
2359 mono_native_thread_set_name (mono_native_thread_id_get (), "SGen worker");
2362 /* Variables holding start/end nursery so it won't have to be passed at every call */
2363 static void *scan_area_arg_start, *scan_area_arg_end;
2366 mono_gc_conservatively_scan_area (void *start, void *end)
2368 sgen_conservatively_pin_objects_from ((void **)start, (void **)end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
2372 mono_gc_scan_object (void *obj, void *gc_data)
2374 ScanCopyContext *ctx = (ScanCopyContext *)gc_data;
2375 ctx->ops->copy_or_mark_object ((GCObject**)&obj, ctx->queue);
2380 * Mark from thread stacks and registers.
2383 sgen_client_scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, ScanCopyContext ctx)
2385 scan_area_arg_start = start_nursery;
2386 scan_area_arg_end = end_nursery;
2388 FOREACH_THREAD (info) {
2389 int skip_reason = 0;
2390 void *aligned_stack_start;
2392 if (info->client_info.skip) {
2393 SGEN_LOG (3, "Skipping dead thread %p, range: %p-%p, size: %zd", info, info->client_info.stack_start, info->client_info.stack_end, (char*)info->client_info.stack_end - (char*)info->client_info.stack_start);
2395 } else if (info->client_info.gc_disabled) {
2396 SGEN_LOG (3, "GC disabled for thread %p, range: %p-%p, size: %zd", info, info->client_info.stack_start, info->client_info.stack_end, (char*)info->client_info.stack_end - (char*)info->client_info.stack_start);
2398 } else if (!mono_thread_info_is_live (info)) {
2399 SGEN_LOG (3, "Skipping non-running thread %p, range: %p-%p, size: %zd (state %x)", info, info->client_info.stack_start, info->client_info.stack_end, (char*)info->client_info.stack_end - (char*)info->client_info.stack_start, info->client_info.info.thread_state);
2401 } else if (!info->client_info.stack_start) {
2402 SGEN_LOG (3, "Skipping starting or detaching thread %p", info);
2406 binary_protocol_scan_stack ((gpointer)mono_thread_info_get_tid (info), info->client_info.stack_start, info->client_info.stack_end, skip_reason);
2410 /* If we skip a thread with a non-empty handle stack and then it
2411 * resumes running we may potentially move an object but fail to
2412 * update the reference in the handle.
2414 HandleStack *stack = info->client_info.info.handle_stack;
2415 g_assert (stack == NULL || mono_handle_stack_is_empty (stack));
2420 g_assert (info->client_info.stack_start);
2421 g_assert (info->client_info.stack_end);
2423 aligned_stack_start = (void*)(mword) ALIGN_TO ((mword)info->client_info.stack_start, SIZEOF_VOID_P);
2425 /* Windows uses a guard page before the committed stack memory pages to detect when the
2426 stack needs to be grown. If we suspend a thread just after a function prolog has
2427 decremented the stack pointer to point into the guard page but before the thread has
2428 been able to read or write to that page, starting the stack scan at aligned_stack_start
2429 will raise a STATUS_GUARD_PAGE_VIOLATION and the process will crash. This code uses
2430 VirtualQuery() to determine whether stack_start points into the guard page and then
2431 updates aligned_stack_start to point at the next non-guard page. */
2432 MEMORY_BASIC_INFORMATION mem_info;
2433 SIZE_T result = VirtualQuery(info->client_info.stack_start, &mem_info, sizeof(mem_info));
2434 g_assert (result != 0);
2435 if (mem_info.Protect & PAGE_GUARD) {
2436 aligned_stack_start = ((char*) mem_info.BaseAddress) + mem_info.RegionSize;
2440 g_assert (info->client_info.suspend_done);
2441 SGEN_LOG (3, "Scanning thread %p, range: %p-%p, size: %zd, pinned=%zd", info, info->client_info.stack_start, info->client_info.stack_end, (char*)info->client_info.stack_end - (char*)info->client_info.stack_start, sgen_get_pinned_count ());
2442 if (mono_gc_get_gc_callbacks ()->thread_mark_func && !conservative_stack_mark) {
2443 mono_gc_get_gc_callbacks ()->thread_mark_func (info->client_info.runtime_data, (guint8 *)aligned_stack_start, (guint8 *)info->client_info.stack_end, precise, &ctx);
2444 } else if (!precise) {
2445 if (!conservative_stack_mark) {
2446 fprintf (stderr, "Precise stack mark not supported - disabling.\n");
2447 conservative_stack_mark = TRUE;
2449 //FIXME we should eventually use the new stack_mark from coop
2450 sgen_conservatively_pin_objects_from ((void **)aligned_stack_start, (void **)info->client_info.stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
2454 sgen_conservatively_pin_objects_from ((void**)&info->client_info.ctx, (void**)(&info->client_info.ctx + 1),
2455 start_nursery, end_nursery, PIN_TYPE_STACK);
2458 // This is used on Coop GC for platforms where we cannot get the data for individual registers.
2459 // We force a spill of all registers into the stack and pass a chunk of data into sgen.
2460 //FIXME under coop, for now, what we need to ensure is that we scan any extra memory from info->client_info.stack_end to stack_mark
2461 MonoThreadUnwindState *state = &info->client_info.info.thread_saved_state [SELF_SUSPEND_STATE_INDEX];
2462 if (state && state->gc_stackdata) {
2463 sgen_conservatively_pin_objects_from ((void **)state->gc_stackdata, (void**)((char*)state->gc_stackdata + state->gc_stackdata_size),
2464 start_nursery, end_nursery, PIN_TYPE_STACK);
2468 if (precise && info->client_info.info.handle_stack) {
2469 mono_handle_stack_scan ((HandleStack*)info->client_info.info.handle_stack, (GcScanFunc)ctx.ops->copy_or_mark_object, ctx.queue);
2471 } FOREACH_THREAD_END
2475 * mono_gc_set_stack_end:
2477 * Set the end of the current threads stack to STACK_END. The stack space between
2478 * STACK_END and the real end of the threads stack will not be scanned during collections.
2481 mono_gc_set_stack_end (void *stack_end)
2483 SgenThreadInfo *info;
2486 info = mono_thread_info_current ();
2488 SGEN_ASSERT (0, stack_end < info->client_info.stack_end, "Can only lower stack end");
2489 info->client_info.stack_end = stack_end;
2499 mono_gc_register_root (char *start, size_t size, MonoGCDescriptor descr, MonoGCRootSource source, const char *msg)
2501 return sgen_register_root (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED, source, msg);
2505 mono_gc_register_root_wbarrier (char *start, size_t size, MonoGCDescriptor descr, MonoGCRootSource source, const char *msg)
2507 return sgen_register_root (start, size, descr, ROOT_TYPE_WBARRIER, source, msg);
2511 mono_gc_deregister_root (char* addr)
2513 sgen_deregister_root (addr);
2522 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
2526 mono_threads_join_lock ();
2527 res = pthread_create (new_thread, attr, start_routine, arg);
2528 mono_threads_join_unlock ();
2539 sgen_client_total_allocated_heap_changed (size_t allocated_heap)
2541 mono_runtime_resource_check_limit (MONO_RESOURCE_GC_HEAP, allocated_heap);
2545 mono_gc_user_markers_supported (void)
2551 mono_object_is_alive (MonoObject* o)
2557 mono_gc_get_generation (MonoObject *obj)
2559 if (sgen_ptr_in_nursery (obj))
2565 mono_gc_get_gc_name (void)
2571 mono_gc_get_description (void)
2573 #ifdef HAVE_CONC_GC_AS_DEFAULT
2574 return g_strdup ("sgen (concurrent by default)");
2576 return g_strdup ("sgen");
2581 mono_gc_set_desktop_mode (void)
2586 mono_gc_is_moving (void)
2592 mono_gc_is_disabled (void)
2598 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
2605 mono_gc_max_generation (void)
2611 mono_gc_precise_stack_mark_enabled (void)
2613 return !conservative_stack_mark;
2617 mono_gc_collect (int generation)
2619 sgen_gc_collect (generation);
2623 mono_gc_collection_count (int generation)
2625 return sgen_gc_collection_count (generation);
2629 mono_gc_get_used_size (void)
2631 return (int64_t)sgen_gc_get_used_size ();
2635 mono_gc_get_heap_size (void)
2637 return (int64_t)sgen_gc_get_total_heap_allocation ();
2641 mono_gc_make_root_descr_user (MonoGCRootMarkFunc marker)
2643 return sgen_make_user_root_descriptor (marker);
2647 mono_gc_make_descr_for_string (gsize *bitmap, int numbits)
2649 return SGEN_DESC_STRING;
2653 mono_gc_get_nursery (int *shift_bits, size_t *size)
2655 *size = sgen_nursery_size;
2656 *shift_bits = DEFAULT_NURSERY_BITS;
2657 return sgen_get_nursery_start ();
2661 mono_gc_get_los_limit (void)
2663 return SGEN_MAX_SMALL_OBJ_SIZE;
2667 sgen_client_default_metadata (void)
2669 return mono_domain_get ();
2673 sgen_client_metadata_for_object (GCObject *obj)
2675 return mono_object_domain (obj);
2679 * mono_gchandle_is_in_domain:
2680 * @gchandle: a GCHandle's handle.
2681 * @domain: An application domain.
2683 * Returns: TRUE if the object wrapped by the @gchandle belongs to the specific @domain.
2686 mono_gchandle_is_in_domain (guint32 gchandle, MonoDomain *domain)
2688 MonoDomain *gchandle_domain = (MonoDomain *)sgen_gchandle_get_metadata (gchandle);
2689 return domain->domain_id == gchandle_domain->domain_id;
2693 * mono_gchandle_free_domain:
2694 * @unloading: domain that is unloading
2696 * Function used internally to cleanup any GC handle for objects belonging
2697 * to the specified domain during appdomain unload.
2700 mono_gchandle_free_domain (MonoDomain *unloading)
2705 null_link_if_in_domain (gpointer hidden, GCHandleType handle_type, int max_generation, gpointer user)
2707 MonoDomain *unloading_domain = (MonoDomain *)user;
2708 MonoDomain *obj_domain;
2709 gboolean is_weak = MONO_GC_HANDLE_TYPE_IS_WEAK (handle_type);
2710 if (MONO_GC_HANDLE_IS_OBJECT_POINTER (hidden)) {
2711 MonoObject *obj = (MonoObject *)MONO_GC_REVEAL_POINTER (hidden, is_weak);
2712 obj_domain = mono_object_domain (obj);
2714 obj_domain = (MonoDomain *)MONO_GC_REVEAL_POINTER (hidden, is_weak);
2716 if (unloading_domain->domain_id == obj_domain->domain_id)
2722 sgen_null_links_for_domain (MonoDomain *domain)
2725 for (type = HANDLE_TYPE_MIN; type < HANDLE_TYPE_MAX; ++type)
2726 sgen_gchandle_iterate ((GCHandleType)type, GENERATION_OLD, null_link_if_in_domain, domain);
2730 mono_gchandle_set_target (guint32 gchandle, MonoObject *obj)
2732 sgen_gchandle_set_target (gchandle, obj);
2736 sgen_client_gchandle_created (int handle_type, GCObject *obj, guint32 handle)
2738 #ifndef DISABLE_PERFCOUNTERS
2739 mono_perfcounters->gc_num_handles++;
2741 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_CREATED, handle_type, handle, obj);
2745 sgen_client_gchandle_destroyed (int handle_type, guint32 handle)
2747 #ifndef DISABLE_PERFCOUNTERS
2748 mono_perfcounters->gc_num_handles--;
2750 mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_DESTROYED, handle_type, handle, NULL);
2754 sgen_client_ensure_weak_gchandles_accessible (void)
2757 * During the second bridge processing step the world is
2758 * running again. That step processes all weak links once
2759 * more to null those that refer to dead objects. Before that
2760 * is completed, those links must not be followed, so we
2761 * conservatively wait for bridge processing when any weak
2762 * link is dereferenced.
2764 /* FIXME: A GC can occur after this check fails, in which case we
2765 * should wait for bridge processing but would fail to do so.
2767 if (G_UNLIKELY (bridge_processing_in_progress))
2768 mono_gc_wait_for_bridge_processing ();
2772 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
2776 result = func (data);
2777 UNLOCK_INTERRUPTION;
2782 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
2788 mono_gc_get_card_table (int *shift_bits, gpointer *mask)
2790 return sgen_get_card_table_configuration (shift_bits, mask);
2794 mono_gc_card_table_nursery_check (void)
2796 return !sgen_get_major_collector ()->is_concurrent;
2799 /* Negative value to remove */
2801 mono_gc_add_memory_pressure (gint64 value)
2803 /* FIXME: Implement at some point? */
2811 sgen_client_degraded_allocation (size_t size)
2813 static int last_major_gc_warned = -1;
2814 static int num_degraded = 0;
2816 if (last_major_gc_warned < (int)gc_stats.major_gc_count) {
2818 if (num_degraded == 1 || num_degraded == 3)
2819 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "Warning: Degraded allocation. Consider increasing nursery-size if the warning persists.");
2820 else if (num_degraded == 10)
2821 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "Warning: Repeated degraded allocation. Consider increasing nursery-size.");
2822 last_major_gc_warned = gc_stats.major_gc_count;
2831 sgen_client_description_for_internal_mem_type (int type)
2834 case INTERNAL_MEM_EPHEMERON_LINK: return "ephemeron-link";
2835 case INTERNAL_MEM_MOVED_OBJECT: return "moved-object";
2842 sgen_client_pre_collection_checks (void)
2844 if (sgen_mono_xdomain_checks) {
2845 sgen_clear_nursery_fragments ();
2846 sgen_check_for_xdomain_refs ();
2851 sgen_client_vtable_is_inited (MonoVTable *vt)
2853 return vt->klass->inited;
2857 sgen_client_vtable_get_namespace (MonoVTable *vt)
2859 return vt->klass->name_space;
2863 sgen_client_vtable_get_name (MonoVTable *vt)
2865 return vt->klass->name;
2873 sgen_client_init (void)
2876 MonoThreadInfoCallbacks cb;
2878 cb.thread_register = sgen_thread_register;
2879 cb.thread_detach = sgen_thread_detach;
2880 cb.thread_unregister = sgen_thread_unregister;
2881 cb.thread_attach = sgen_thread_attach;
2882 cb.mono_thread_in_critical_region = thread_in_critical_region;
2883 cb.ip_in_critical_region = ip_in_critical_region;
2885 mono_threads_init (&cb, sizeof (SgenThreadInfo));
2887 ///* Keep this the default for now */
2888 /* Precise marking is broken on all supported targets. Disable until fixed. */
2889 conservative_stack_mark = TRUE;
2891 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
2893 mono_sgen_init_stw ();
2895 mono_tls_init_gc_keys ();
2897 mono_gc_register_thread (&dummy);
2901 sgen_client_handle_gc_param (const char *opt)
2903 if (g_str_has_prefix (opt, "stack-mark=")) {
2904 opt = strchr (opt, '=') + 1;
2905 if (!strcmp (opt, "precise")) {
2906 conservative_stack_mark = FALSE;
2907 } else if (!strcmp (opt, "conservative")) {
2908 conservative_stack_mark = TRUE;
2910 sgen_env_var_error (MONO_GC_PARAMS_NAME, conservative_stack_mark ? "Using `conservative`." : "Using `precise`.",
2911 "Invalid value `%s` for `stack-mark` option, possible values are: `precise`, `conservative`.", opt);
2913 } else if (g_str_has_prefix (opt, "bridge-implementation=")) {
2914 opt = strchr (opt, '=') + 1;
2915 sgen_set_bridge_implementation (opt);
2916 } else if (g_str_has_prefix (opt, "toggleref-test")) {
2917 /* FIXME: This should probably in MONO_GC_DEBUG */
2918 sgen_register_test_toggleref_callback ();
2919 } else if (!sgen_bridge_handle_gc_param (opt)) {
2926 sgen_client_print_gc_params_usage (void)
2928 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
2932 sgen_client_handle_gc_debug (const char *opt)
2934 if (!strcmp (opt, "xdomain-checks")) {
2935 sgen_mono_xdomain_checks = TRUE;
2936 } else if (!strcmp (opt, "do-not-finalize")) {
2937 mono_do_not_finalize = TRUE;
2938 } else if (g_str_has_prefix (opt, "do-not-finalize=")) {
2939 opt = strchr (opt, '=') + 1;
2940 mono_do_not_finalize = TRUE;
2941 mono_do_not_finalize_class_names = g_strsplit (opt, ",", 0);
2942 } else if (!strcmp (opt, "log-finalizers")) {
2943 log_finalizers = TRUE;
2944 } else if (!strcmp (opt, "no-managed-allocator")) {
2945 sgen_set_use_managed_allocator (FALSE);
2946 } else if (!sgen_bridge_handle_gc_debug (opt)) {
2953 sgen_client_print_gc_debug_usage (void)
2955 fprintf (stderr, " xdomain-checks\n");
2956 fprintf (stderr, " do-not-finalize\n");
2957 fprintf (stderr, " log-finalizers\n");
2958 fprintf (stderr, " no-managed-allocator\n");
2959 sgen_bridge_print_gc_debug_usage ();
2964 sgen_client_get_provenance (void)
2966 #ifdef SGEN_OBJECT_PROVENANCE
2967 MonoGCCallbacks *cb = mono_gc_get_gc_callbacks ();
2968 gpointer (*get_provenance_func) (void);
2971 get_provenance_func = cb->get_provenance_func;
2972 if (get_provenance_func)
2973 return get_provenance_func ();
2981 sgen_client_describe_invalid_pointer (GCObject *ptr)
2983 sgen_bridge_describe_pointer (ptr);
2986 static gboolean gc_inited;
2989 mono_gc_base_init (void)
2994 mono_counters_init ();
2997 mono_w32handle_init ();
3000 #ifdef HEAVY_STATISTICS
3001 mono_counters_register ("los marked cards", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &los_marked_cards);
3002 mono_counters_register ("los array cards scanned ", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &los_array_cards);
3003 mono_counters_register ("los array remsets", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &los_array_remsets);
3005 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_set_arrayref);
3006 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_value_copy);
3007 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_object_copy);
3016 mono_gc_base_cleanup (void)
3018 sgen_thread_pool_shutdown ();
3020 // We should have consumed any outstanding moves.
3021 g_assert (sgen_pointer_queue_is_empty (&moved_objects_queue));
3025 mono_gc_is_null (void)