2 * sgen-alloc.c: Object allocation routines + managed allocators
5 * Paolo Molaro (lupus@ximian.com)
6 * Rodrigo Kumpera (kumpera@gmail.com)
8 * Copyright 2005-2011 Novell, Inc (http://www.novell.com)
9 * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
10 * Copyright 2011 Xamarin, Inc.
12 * Permission is hereby granted, free of charge, to any person obtaining
13 * a copy of this software and associated documentation files (the
14 * "Software"), to deal in the Software without restriction, including
15 * without limitation the rights to use, copy, modify, merge, publish,
16 * distribute, sublicense, and/or sell copies of the Software, and to
17 * permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
20 * The above copyright notice and this permission notice shall be
21 * included in all copies or substantial portions of the Software.
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
27 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
28 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
29 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
33 * ######################################################################
34 * ######## Object allocation
35 * ######################################################################
36 * This section of code deals with allocating memory for objects.
37 * There are several ways:
38 * *) allocate large objects
39 * *) allocate normal objects
40 * *) fast lock-free allocation
41 * *) allocation of pinned objects
47 #include "metadata/sgen-gc.h"
48 #include "metadata/sgen-protocol.h"
49 #include "metadata/profiler-private.h"
50 #include "metadata/marshal.h"
51 #include "metadata/method-builder.h"
52 #include "utils/mono-memory-model.h"
53 #include "utils/mono-counters.h"
55 #define ALIGN_UP SGEN_ALIGN_UP
56 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
57 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
58 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
59 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
61 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
65 #include "mono/cil/opcode.def"
71 #ifdef HEAVY_STATISTICS
72 static long long stat_objects_alloced = 0;
73 static long long stat_bytes_alloced = 0;
74 static long long stat_bytes_alloced_los = 0;
79 * Allocation is done from a Thread Local Allocation Buffer (TLAB). TLABs are allocated
80 * from nursery fragments.
81 * tlab_next is the pointer to the space inside the TLAB where the next object will
83 * tlab_temp_end is the pointer to the end of the temporary space reserved for
84 * the allocation: it allows us to set the scan starts at reasonable intervals.
85 * tlab_real_end points to the end of the TLAB.
89 * FIXME: What is faster, a TLS variable pointing to a structure, or separate TLS
90 * variables for next+temp_end ?
93 static __thread char *tlab_start;
94 static __thread char *tlab_next;
95 static __thread char *tlab_temp_end;
96 static __thread char *tlab_real_end;
97 /* Used by the managed allocator/wbarrier */
98 static __thread char **tlab_next_addr;
101 #ifdef HAVE_KW_THREAD
102 #define TLAB_START tlab_start
103 #define TLAB_NEXT tlab_next
104 #define TLAB_TEMP_END tlab_temp_end
105 #define TLAB_REAL_END tlab_real_end
107 #define TLAB_START (__thread_info__->tlab_start)
108 #define TLAB_NEXT (__thread_info__->tlab_next)
109 #define TLAB_TEMP_END (__thread_info__->tlab_temp_end)
110 #define TLAB_REAL_END (__thread_info__->tlab_real_end)
114 set_nursery_scan_start (char *p)
116 int idx = (p - (char*)nursery_section->data) / SGEN_SCAN_START_SIZE;
117 char *old = nursery_section->scan_starts [idx];
119 nursery_section->scan_starts [idx] = p;
123 alloc_degraded (MonoVTable *vtable, size_t size, gboolean for_mature)
125 static int last_major_gc_warned = -1;
126 static int num_degraded = 0;
129 if (last_major_gc_warned < stat_major_gcs) {
131 if (num_degraded == 1 || num_degraded == 3)
132 fprintf (stderr, "Warning: Degraded allocation. Consider increasing nursery-size if the warning persists.\n");
133 else if (num_degraded == 10)
134 fprintf (stderr, "Warning: Repeated degraded allocation. Consider increasing nursery-size.\n");
135 last_major_gc_warned = stat_major_gcs;
139 if (mono_sgen_need_major_collection (0)) {
140 sgen_collect_major_no_lock ("degraded overflow");
143 return major_collector.alloc_degraded (vtable, size);
147 * Provide a variant that takes just the vtable for small fixed-size objects.
148 * The aligned size is already computed and stored in vt->gc_descr.
149 * Note: every SGEN_SCAN_START_SIZE or so we are given the chance to do some special
150 * processing. We can keep track of where objects start, for example,
151 * so when we scan the thread stacks for pinned objects, we can start
152 * a search for the pinned object in SGEN_SCAN_START_SIZE chunks.
155 mono_gc_alloc_obj_nolock (MonoVTable *vtable, size_t size)
157 /* FIXME: handle OOM */
162 HEAVY_STAT (++stat_objects_alloced);
163 if (size <= SGEN_MAX_SMALL_OBJ_SIZE)
164 HEAVY_STAT (stat_bytes_alloced += size);
166 HEAVY_STAT (stat_bytes_alloced_los += size);
168 size = ALIGN_UP (size);
170 g_assert (vtable->gc_descr);
172 if (G_UNLIKELY (collect_before_allocs)) {
173 static int alloc_count;
175 InterlockedIncrement (&alloc_count);
176 if (((alloc_count % collect_before_allocs) == 0) && nursery_section) {
177 mono_sgen_collect_nursery_no_lock (0);
178 if (!degraded_mode && !mono_sgen_can_alloc_size (size) && size <= SGEN_MAX_SMALL_OBJ_SIZE) {
180 g_assert_not_reached ();
186 * We must already have the lock here instead of after the
187 * fast path because we might be interrupted in the fast path
188 * (after confirming that new_next < TLAB_TEMP_END) by the GC,
189 * and we'll end up allocating an object in a fragment which
190 * no longer belongs to us.
192 * The managed allocator does not do this, but it's treated
193 * specially by the world-stopping code.
196 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
197 p = mono_sgen_los_alloc_large_inner (vtable, size);
199 /* tlab_next and tlab_temp_end are TLS vars so accessing them might be expensive */
201 p = (void**)TLAB_NEXT;
202 /* FIXME: handle overflow */
203 new_next = (char*)p + size;
204 TLAB_NEXT = new_next;
206 if (G_LIKELY (new_next < TLAB_TEMP_END)) {
210 * FIXME: We might need a memory barrier here so the change to tlab_next is
211 * visible before the vtable store.
214 DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
215 binary_protocol_alloc (p , vtable, size);
216 g_assert (*p == NULL);
217 mono_atomic_store_seq (p, vtable);
224 /* there are two cases: the object is too big or we run out of space in the TLAB */
225 /* we also reach here when the thread does its first allocation after a minor
226 * collection, since the tlab_ variables are initialized to NULL.
227 * there can be another case (from ORP), if we cooperate with the runtime a bit:
228 * objects that need finalizers can have the high bit set in their size
229 * so the above check fails and we can readily add the object to the queue.
230 * This avoids taking again the GC lock when registering, but this is moot when
231 * doing thread-local allocation, so it may not be a good idea.
233 if (TLAB_NEXT >= TLAB_REAL_END) {
234 int available_in_tlab;
236 * Run out of space in the TLAB. When this happens, some amount of space
237 * remains in the TLAB, but not enough to satisfy the current allocation
238 * request. Currently, we retire the TLAB in all cases, later we could
239 * keep it if the remaining space is above a treshold, and satisfy the
240 * allocation directly from the nursery.
243 /* when running in degraded mode, we continue allocing that way
244 * for a while, to decrease the number of useless nursery collections.
246 if (degraded_mode && degraded_mode < DEFAULT_NURSERY_SIZE) {
247 p = alloc_degraded (vtable, size, FALSE);
248 binary_protocol_alloc_degraded (p, vtable, size);
252 available_in_tlab = TLAB_REAL_END - TLAB_NEXT;
253 if (size > tlab_size || available_in_tlab > SGEN_MAX_NURSERY_WASTE) {
254 /* Allocate directly from the nursery */
256 p = mono_sgen_nursery_alloc (size);
258 mono_sgen_minor_collect_or_expand_inner (size);
260 p = alloc_degraded (vtable, size, FALSE);
261 binary_protocol_alloc_degraded (p, vtable, size);
264 p = mono_sgen_nursery_alloc (size);
273 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION) {
279 DEBUG (3, fprintf (gc_debug_file, "Retire TLAB: %p-%p [%ld]\n", TLAB_START, TLAB_REAL_END, (long)(TLAB_REAL_END - TLAB_NEXT - size)));
280 mono_sgen_nursery_retire_region (p, available_in_tlab);
283 p = mono_sgen_nursery_alloc_range (tlab_size, size, &alloc_size);
285 mono_sgen_minor_collect_or_expand_inner (tlab_size);
287 p = alloc_degraded (vtable, size, FALSE);
288 binary_protocol_alloc_degraded (p, vtable, size);
291 p = mono_sgen_nursery_alloc_range (tlab_size, size, &alloc_size);
301 /* Allocate a new TLAB from the current nursery fragment */
302 TLAB_START = (char*)p;
303 TLAB_NEXT = TLAB_START;
304 TLAB_REAL_END = TLAB_START + alloc_size;
305 TLAB_TEMP_END = TLAB_START + MIN (SGEN_SCAN_START_SIZE, alloc_size);
307 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION) {
308 memset (TLAB_START, 0, alloc_size);
311 /* Allocate from the TLAB */
312 p = (void*)TLAB_NEXT;
314 set_nursery_scan_start ((char*)p);
317 /* Reached tlab_temp_end */
319 /* record the scan start so we can find pinned objects more easily */
320 set_nursery_scan_start ((char*)p);
321 /* we just bump tlab_temp_end as well */
322 TLAB_TEMP_END = MIN (TLAB_REAL_END, TLAB_NEXT + SGEN_SCAN_START_SIZE);
323 DEBUG (5, fprintf (gc_debug_file, "Expanding local alloc: %p-%p\n", TLAB_NEXT, TLAB_TEMP_END));
328 DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
329 binary_protocol_alloc (p, vtable, size);
330 mono_atomic_store_seq (p, vtable);
337 mono_gc_try_alloc_obj_nolock (MonoVTable *vtable, size_t size)
343 size = ALIGN_UP (size);
345 g_assert (vtable->gc_descr);
346 if (size > SGEN_MAX_SMALL_OBJ_SIZE)
349 if (G_UNLIKELY (size > tlab_size)) {
350 /* Allocate directly from the nursery */
351 p = mono_sgen_nursery_alloc (size);
354 set_nursery_scan_start ((char*)p);
356 /*FIXME we should use weak memory ops here. Should help specially on x86. */
357 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
360 int available_in_tlab;
362 /* tlab_next and tlab_temp_end are TLS vars so accessing them might be expensive */
364 p = (void**)TLAB_NEXT;
365 /* FIXME: handle overflow */
366 new_next = (char*)p + size;
368 real_end = TLAB_REAL_END;
369 available_in_tlab = real_end - (char*)p;
371 if (G_LIKELY (new_next < real_end)) {
372 TLAB_NEXT = new_next;
374 /* Second case, we overflowed temp end */
375 if (G_UNLIKELY (new_next >= TLAB_TEMP_END)) {
376 set_nursery_scan_start (new_next);
377 /* we just bump tlab_temp_end as well */
378 TLAB_TEMP_END = MIN (TLAB_REAL_END, TLAB_NEXT + SGEN_SCAN_START_SIZE);
379 DEBUG (5, fprintf (gc_debug_file, "Expanding local alloc: %p-%p\n", TLAB_NEXT, TLAB_TEMP_END));
381 } else if (available_in_tlab > SGEN_MAX_NURSERY_WASTE) {
382 /* Allocate directly from the nursery */
383 p = mono_sgen_nursery_alloc (size);
387 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
392 mono_sgen_nursery_retire_region (p, available_in_tlab);
393 new_next = mono_sgen_nursery_alloc_range (tlab_size, size, &alloc_size);
394 p = (void**)new_next;
398 TLAB_START = (char*)new_next;
399 TLAB_NEXT = new_next + size;
400 TLAB_REAL_END = new_next + alloc_size;
401 TLAB_TEMP_END = new_next + MIN (SGEN_SCAN_START_SIZE, alloc_size);
402 set_nursery_scan_start ((char*)p);
404 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
405 memset (new_next, 0, alloc_size);
409 HEAVY_STAT (++stat_objects_alloced);
410 HEAVY_STAT (stat_bytes_alloced += size);
412 DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
413 binary_protocol_alloc (p, vtable, size);
414 g_assert (*p == NULL); /* FIXME disable this in non debug builds */
416 mono_atomic_store_seq (p, vtable);
422 mono_gc_alloc_obj (MonoVTable *vtable, size_t size)
425 #ifndef DISABLE_CRITICAL_REGION
427 ENTER_CRITICAL_REGION;
428 res = mono_gc_try_alloc_obj_nolock (vtable, size);
430 EXIT_CRITICAL_REGION;
433 EXIT_CRITICAL_REGION;
436 res = mono_gc_alloc_obj_nolock (vtable, size);
438 if (G_UNLIKELY (!res))
439 return mono_gc_out_of_memory (size);
444 mono_gc_alloc_vector (MonoVTable *vtable, size_t size, uintptr_t max_length)
447 #ifndef DISABLE_CRITICAL_REGION
449 ENTER_CRITICAL_REGION;
450 arr = mono_gc_try_alloc_obj_nolock (vtable, size);
452 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
453 arr->max_length = max_length;
454 EXIT_CRITICAL_REGION;
457 EXIT_CRITICAL_REGION;
462 arr = mono_gc_alloc_obj_nolock (vtable, size);
463 if (G_UNLIKELY (!arr)) {
465 return mono_gc_out_of_memory (size);
468 arr->max_length = max_length;
476 mono_gc_alloc_array (MonoVTable *vtable, size_t size, uintptr_t max_length, uintptr_t bounds_size)
479 MonoArrayBounds *bounds;
483 arr = mono_gc_alloc_obj_nolock (vtable, size);
484 if (G_UNLIKELY (!arr)) {
486 return mono_gc_out_of_memory (size);
489 arr->max_length = max_length;
491 bounds = (MonoArrayBounds*)((char*)arr + size - bounds_size);
492 arr->bounds = bounds;
500 mono_gc_alloc_string (MonoVTable *vtable, size_t size, gint32 len)
503 #ifndef DISABLE_CRITICAL_REGION
505 ENTER_CRITICAL_REGION;
506 str = mono_gc_try_alloc_obj_nolock (vtable, size);
508 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
510 EXIT_CRITICAL_REGION;
513 EXIT_CRITICAL_REGION;
518 str = mono_gc_alloc_obj_nolock (vtable, size);
519 if (G_UNLIKELY (!str)) {
521 return mono_gc_out_of_memory (size);
532 * To be used for interned strings and possibly MonoThread, reflection handles.
533 * We may want to explicitly free these objects.
536 mono_gc_alloc_pinned_obj (MonoVTable *vtable, size_t size)
539 size = ALIGN_UP (size);
542 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
543 /* large objects are always pinned anyway */
544 p = mono_sgen_los_alloc_large_inner (vtable, size);
546 DEBUG (9, g_assert (vtable->klass->inited));
547 p = major_collector.alloc_small_pinned_obj (size, SGEN_VTABLE_HAS_REFERENCES (vtable));
550 DEBUG (6, fprintf (gc_debug_file, "Allocated pinned object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
551 binary_protocol_alloc_pinned (p, vtable, size);
552 mono_atomic_store_seq (p, vtable);
559 mono_gc_alloc_mature (MonoVTable *vtable)
562 size_t size = ALIGN_UP (vtable->klass->instance_size);
564 res = alloc_degraded (vtable, size, TRUE);
565 mono_atomic_store_seq (res, vtable);
567 if (G_UNLIKELY (vtable->klass->has_finalize))
568 mono_object_register_finalizer ((MonoObject*)res);
574 mono_gc_alloc_fixed (size_t size, void *descr)
576 /* FIXME: do a single allocation */
577 void *res = calloc (1, size);
580 if (!mono_gc_register_root (res, size, descr)) {
588 mono_gc_free_fixed (void* addr)
590 mono_gc_deregister_root (addr);
595 mono_sgen_init_tlab_info (SgenThreadInfo* info)
597 #ifndef HAVE_KW_THREAD
598 SgenThreadInfo *__thread_info__ = info;
601 info->tlab_start_addr = &TLAB_START;
602 info->tlab_next_addr = &TLAB_NEXT;
603 info->tlab_temp_end_addr = &TLAB_TEMP_END;
604 info->tlab_real_end_addr = &TLAB_REAL_END;
606 #ifdef HAVE_KW_THREAD
607 tlab_next_addr = &tlab_next;
612 * Clear the thread local TLAB variables for all threads.
615 mono_sgen_clear_tlabs (void)
617 SgenThreadInfo *info;
619 FOREACH_THREAD (info) {
620 /* A new TLAB will be allocated when the thread does its first allocation */
621 *info->tlab_start_addr = NULL;
622 *info->tlab_next_addr = NULL;
623 *info->tlab_temp_end_addr = NULL;
624 *info->tlab_real_end_addr = NULL;
628 static MonoMethod* alloc_method_cache [ATYPE_NUM];
630 #ifdef MANAGED_ALLOCATION
631 /* FIXME: Do this in the JIT, where specialized allocation sequences can be created
632 * for each class. This is currently not easy to do, as it is hard to generate basic
633 * blocks + branches, but it is easy with the linear IL codebase.
635 * For this to work we'd need to solve the TLAB race, first. Now we
636 * require the allocator to be in a few known methods to make sure
637 * that they are executed atomically via the restart mechanism.
640 create_allocator (int atype)
643 guint32 slowpath_branch, max_size_branch;
644 MonoMethodBuilder *mb;
646 MonoMethodSignature *csig;
647 static gboolean registered = FALSE;
648 int tlab_next_addr_var, new_next_var;
650 const char *name = NULL;
651 AllocatorWrapperInfo *info;
653 #ifdef HAVE_KW_THREAD
654 int tlab_next_addr_offset = -1;
655 int tlab_temp_end_offset = -1;
657 MONO_THREAD_VAR_OFFSET (tlab_next_addr, tlab_next_addr_offset);
658 MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
660 g_assert (tlab_next_addr_offset != -1);
661 g_assert (tlab_temp_end_offset != -1);
665 mono_register_jit_icall (mono_gc_alloc_obj, "mono_gc_alloc_obj", mono_create_icall_signature ("object ptr int"), FALSE);
666 mono_register_jit_icall (mono_gc_alloc_vector, "mono_gc_alloc_vector", mono_create_icall_signature ("object ptr int int"), FALSE);
670 if (atype == ATYPE_SMALL) {
673 } else if (atype == ATYPE_NORMAL) {
676 } else if (atype == ATYPE_VECTOR) {
678 name = "AllocVector";
680 g_assert_not_reached ();
683 csig = mono_metadata_signature_alloc (mono_defaults.corlib, num_params);
684 csig->ret = &mono_defaults.object_class->byval_arg;
685 for (i = 0; i < num_params; ++i)
686 csig->params [i] = &mono_defaults.int_class->byval_arg;
688 mb = mono_mb_new (mono_defaults.object_class, name, MONO_WRAPPER_ALLOC);
689 size_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
690 if (atype == ATYPE_NORMAL || atype == ATYPE_SMALL) {
691 /* size = vtable->klass->instance_size; */
692 mono_mb_emit_ldarg (mb, 0);
693 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass));
694 mono_mb_emit_byte (mb, CEE_ADD);
695 mono_mb_emit_byte (mb, CEE_LDIND_I);
696 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, instance_size));
697 mono_mb_emit_byte (mb, CEE_ADD);
698 /* FIXME: assert instance_size stays a 4 byte integer */
699 mono_mb_emit_byte (mb, CEE_LDIND_U4);
700 mono_mb_emit_stloc (mb, size_var);
701 } else if (atype == ATYPE_VECTOR) {
702 MonoExceptionClause *clause;
704 MonoClass *oom_exc_class;
707 /* n > MONO_ARRAY_MAX_INDEX -> OverflowException */
708 mono_mb_emit_ldarg (mb, 1);
709 mono_mb_emit_icon (mb, MONO_ARRAY_MAX_INDEX);
710 pos = mono_mb_emit_short_branch (mb, CEE_BLE_UN_S);
711 mono_mb_emit_exception (mb, "OverflowException", NULL);
712 mono_mb_patch_short_branch (mb, pos);
714 clause = mono_image_alloc0 (mono_defaults.corlib, sizeof (MonoExceptionClause));
715 clause->try_offset = mono_mb_get_label (mb);
717 /* vtable->klass->sizes.element_size */
718 mono_mb_emit_ldarg (mb, 0);
719 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass));
720 mono_mb_emit_byte (mb, CEE_ADD);
721 mono_mb_emit_byte (mb, CEE_LDIND_I);
722 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, sizes.element_size));
723 mono_mb_emit_byte (mb, CEE_ADD);
724 mono_mb_emit_byte (mb, CEE_LDIND_U4);
727 mono_mb_emit_ldarg (mb, 1);
728 mono_mb_emit_byte (mb, CEE_MUL_OVF_UN);
729 /* + sizeof (MonoArray) */
730 mono_mb_emit_icon (mb, sizeof (MonoArray));
731 mono_mb_emit_byte (mb, CEE_ADD_OVF_UN);
732 mono_mb_emit_stloc (mb, size_var);
734 pos_leave = mono_mb_emit_branch (mb, CEE_LEAVE);
737 clause->flags = MONO_EXCEPTION_CLAUSE_NONE;
738 clause->try_len = mono_mb_get_pos (mb) - clause->try_offset;
739 clause->data.catch_class = mono_class_from_name (mono_defaults.corlib,
740 "System", "OverflowException");
741 g_assert (clause->data.catch_class);
742 clause->handler_offset = mono_mb_get_label (mb);
744 oom_exc_class = mono_class_from_name (mono_defaults.corlib,
745 "System", "OutOfMemoryException");
746 g_assert (oom_exc_class);
747 ctor = mono_class_get_method_from_name (oom_exc_class, ".ctor", 0);
750 mono_mb_emit_byte (mb, CEE_POP);
751 mono_mb_emit_op (mb, CEE_NEWOBJ, ctor);
752 mono_mb_emit_byte (mb, CEE_THROW);
754 clause->handler_len = mono_mb_get_pos (mb) - clause->handler_offset;
755 mono_mb_set_clauses (mb, 1, clause);
756 mono_mb_patch_branch (mb, pos_leave);
759 g_assert_not_reached ();
762 /* size += ALLOC_ALIGN - 1; */
763 mono_mb_emit_ldloc (mb, size_var);
764 mono_mb_emit_icon (mb, ALLOC_ALIGN - 1);
765 mono_mb_emit_byte (mb, CEE_ADD);
766 /* size &= ~(ALLOC_ALIGN - 1); */
767 mono_mb_emit_icon (mb, ~(ALLOC_ALIGN - 1));
768 mono_mb_emit_byte (mb, CEE_AND);
769 mono_mb_emit_stloc (mb, size_var);
771 /* if (size > MAX_SMALL_OBJ_SIZE) goto slowpath */
772 if (atype != ATYPE_SMALL) {
773 mono_mb_emit_ldloc (mb, size_var);
774 mono_mb_emit_icon (mb, MAX_SMALL_OBJ_SIZE);
775 max_size_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S);
779 * We need to modify tlab_next, but the JIT only supports reading, so we read
780 * another tls var holding its address instead.
783 /* tlab_next_addr (local) = tlab_next_addr (TLS var) */
784 tlab_next_addr_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
785 EMIT_TLS_ACCESS (mb, tlab_next_addr, tlab_next_addr_offset);
786 mono_mb_emit_stloc (mb, tlab_next_addr_var);
788 /* p = (void**)tlab_next; */
789 p_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
790 mono_mb_emit_ldloc (mb, tlab_next_addr_var);
791 mono_mb_emit_byte (mb, CEE_LDIND_I);
792 mono_mb_emit_stloc (mb, p_var);
794 /* new_next = (char*)p + size; */
795 new_next_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
796 mono_mb_emit_ldloc (mb, p_var);
797 mono_mb_emit_ldloc (mb, size_var);
798 mono_mb_emit_byte (mb, CEE_CONV_I);
799 mono_mb_emit_byte (mb, CEE_ADD);
800 mono_mb_emit_stloc (mb, new_next_var);
802 /* if (G_LIKELY (new_next < tlab_temp_end)) */
803 mono_mb_emit_ldloc (mb, new_next_var);
804 EMIT_TLS_ACCESS (mb, tlab_temp_end, tlab_temp_end_offset);
805 slowpath_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
808 if (atype != ATYPE_SMALL)
809 mono_mb_patch_short_branch (mb, max_size_branch);
811 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
812 mono_mb_emit_byte (mb, CEE_MONO_NOT_TAKEN);
814 /* FIXME: mono_gc_alloc_obj takes a 'size_t' as an argument, not an int32 */
815 mono_mb_emit_ldarg (mb, 0);
816 mono_mb_emit_ldloc (mb, size_var);
817 if (atype == ATYPE_NORMAL || atype == ATYPE_SMALL) {
818 mono_mb_emit_icall (mb, mono_gc_alloc_obj);
819 } else if (atype == ATYPE_VECTOR) {
820 mono_mb_emit_ldarg (mb, 1);
821 mono_mb_emit_icall (mb, mono_gc_alloc_vector);
823 g_assert_not_reached ();
825 mono_mb_emit_byte (mb, CEE_RET);
828 mono_mb_patch_short_branch (mb, slowpath_branch);
830 /* FIXME: Memory barrier */
832 /* tlab_next = new_next */
833 mono_mb_emit_ldloc (mb, tlab_next_addr_var);
834 mono_mb_emit_ldloc (mb, new_next_var);
835 mono_mb_emit_byte (mb, CEE_STIND_I);
837 /*The tlab store must be visible before the the vtable store. This could be replaced with a DDS but doing it with IL would be tricky. */
838 mono_mb_emit_byte ((mb), MONO_CUSTOM_PREFIX);
839 mono_mb_emit_op (mb, CEE_MONO_MEMORY_BARRIER, StoreStoreBarrier);
842 mono_mb_emit_ldloc (mb, p_var);
843 mono_mb_emit_ldarg (mb, 0);
844 mono_mb_emit_byte (mb, CEE_STIND_I);
846 if (atype == ATYPE_VECTOR) {
847 /* arr->max_length = max_length; */
848 mono_mb_emit_ldloc (mb, p_var);
849 mono_mb_emit_ldflda (mb, G_STRUCT_OFFSET (MonoArray, max_length));
850 mono_mb_emit_ldarg (mb, 1);
851 mono_mb_emit_byte (mb, CEE_STIND_I);
855 We must make sure both vtable and max_length are globaly visible before returning to managed land.
857 mono_mb_emit_byte ((mb), MONO_CUSTOM_PREFIX);
858 mono_mb_emit_op (mb, CEE_MONO_MEMORY_BARRIER, StoreStoreBarrier);
861 mono_mb_emit_ldloc (mb, p_var);
862 mono_mb_emit_byte (mb, CEE_RET);
864 res = mono_mb_create_method (mb, csig, 8);
866 mono_method_get_header (res)->init_locals = FALSE;
868 info = mono_image_alloc0 (mono_defaults.corlib, sizeof (AllocatorWrapperInfo));
869 info->gc_name = "sgen";
870 info->alloc_type = atype;
871 mono_marshal_set_wrapper_info (res, info);
878 * Generate an allocator method implementing the fast path of mono_gc_alloc_obj ().
879 * The signature of the called method is:
880 * object allocate (MonoVTable *vtable)
883 mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box)
885 #ifdef MANAGED_ALLOCATION
886 MonoClass *klass = vtable->klass;
888 #ifdef HAVE_KW_THREAD
889 int tlab_next_offset = -1;
890 int tlab_temp_end_offset = -1;
891 MONO_THREAD_VAR_OFFSET (tlab_next, tlab_next_offset);
892 MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
894 if (tlab_next_offset == -1 || tlab_temp_end_offset == -1)
898 if (!mono_runtime_has_tls_get ())
900 if (klass->instance_size > tlab_size)
902 if (klass->has_finalize || klass->marshalbyref || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS))
906 if (klass->byval_arg.type == MONO_TYPE_STRING)
908 if (collect_before_allocs)
911 if (ALIGN_TO (klass->instance_size, ALLOC_ALIGN) < MAX_SMALL_OBJ_SIZE)
912 return mono_gc_get_managed_allocator_by_type (ATYPE_SMALL);
914 return mono_gc_get_managed_allocator_by_type (ATYPE_NORMAL);
921 mono_gc_get_managed_array_allocator (MonoVTable *vtable, int rank)
923 #ifdef MANAGED_ALLOCATION
924 MonoClass *klass = vtable->klass;
926 #ifdef HAVE_KW_THREAD
927 int tlab_next_offset = -1;
928 int tlab_temp_end_offset = -1;
929 MONO_THREAD_VAR_OFFSET (tlab_next, tlab_next_offset);
930 MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
932 if (tlab_next_offset == -1 || tlab_temp_end_offset == -1)
938 if (!mono_runtime_has_tls_get ())
940 if (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS)
942 if (collect_before_allocs)
944 g_assert (!mono_class_has_finalizer (klass) && !klass->marshalbyref);
946 return mono_gc_get_managed_allocator_by_type (ATYPE_VECTOR);
953 mono_gc_get_managed_allocator_by_type (int atype)
955 #ifdef MANAGED_ALLOCATION
958 if (!mono_runtime_has_tls_get ())
962 res = alloc_method_cache [atype];
964 res = alloc_method_cache [atype] = create_allocator (atype);
965 mono_loader_unlock ();
973 mono_gc_get_managed_allocator_types (void)
979 mono_sgen_is_managed_allocator (MonoMethod *method)
983 for (i = 0; i < ATYPE_NUM; ++i)
984 if (method == alloc_method_cache [i])
989 #ifdef HEAVY_STATISTICS
991 mono_sgen_alloc_init_heavy_stats (void)
993 mono_counters_register ("# objects allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced);
994 mono_counters_register ("bytes allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced);
995 mono_counters_register ("bytes allocated in LOS", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_los);
999 #endif /*HAVE_SGEN_GC*/