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/sgen-memory-governor.h"
50 #include "metadata/profiler-private.h"
51 #include "metadata/marshal.h"
52 #include "metadata/method-builder.h"
53 #include "utils/mono-memory-model.h"
54 #include "utils/mono-counters.h"
56 #define ALIGN_UP SGEN_ALIGN_UP
57 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
58 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
59 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
60 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
62 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
66 #include "mono/cil/opcode.def"
72 #ifdef HEAVY_STATISTICS
73 static long long stat_objects_alloced = 0;
74 static long long stat_bytes_alloced = 0;
75 static long long stat_bytes_alloced_los = 0;
80 * Allocation is done from a Thread Local Allocation Buffer (TLAB). TLABs are allocated
81 * from nursery fragments.
82 * tlab_next is the pointer to the space inside the TLAB where the next object will
84 * tlab_temp_end is the pointer to the end of the temporary space reserved for
85 * the allocation: it allows us to set the scan starts at reasonable intervals.
86 * tlab_real_end points to the end of the TLAB.
90 * FIXME: What is faster, a TLS variable pointing to a structure, or separate TLS
91 * variables for next+temp_end ?
94 static __thread char *tlab_start;
95 static __thread char *tlab_next;
96 static __thread char *tlab_temp_end;
97 static __thread char *tlab_real_end;
98 /* Used by the managed allocator/wbarrier */
99 static __thread char **tlab_next_addr;
102 #ifdef HAVE_KW_THREAD
103 #define TLAB_START tlab_start
104 #define TLAB_NEXT tlab_next
105 #define TLAB_TEMP_END tlab_temp_end
106 #define TLAB_REAL_END tlab_real_end
108 #define TLAB_START (__thread_info__->tlab_start)
109 #define TLAB_NEXT (__thread_info__->tlab_next)
110 #define TLAB_TEMP_END (__thread_info__->tlab_temp_end)
111 #define TLAB_REAL_END (__thread_info__->tlab_real_end)
115 alloc_degraded (MonoVTable *vtable, size_t size, gboolean for_mature)
117 static int last_major_gc_warned = -1;
118 static int num_degraded = 0;
121 if (last_major_gc_warned < stat_major_gcs) {
123 if (num_degraded == 1 || num_degraded == 3)
124 fprintf (stderr, "Warning: Degraded allocation. Consider increasing nursery-size if the warning persists.\n");
125 else if (num_degraded == 10)
126 fprintf (stderr, "Warning: Repeated degraded allocation. Consider increasing nursery-size.\n");
127 last_major_gc_warned = stat_major_gcs;
129 InterlockedExchangeAdd (°raded_mode, size);
132 sgen_ensure_free_space (size);
134 return major_collector.alloc_degraded (vtable, size);
138 * Provide a variant that takes just the vtable for small fixed-size objects.
139 * The aligned size is already computed and stored in vt->gc_descr.
140 * Note: every SGEN_SCAN_START_SIZE or so we are given the chance to do some special
141 * processing. We can keep track of where objects start, for example,
142 * so when we scan the thread stacks for pinned objects, we can start
143 * a search for the pinned object in SGEN_SCAN_START_SIZE chunks.
146 mono_gc_alloc_obj_nolock (MonoVTable *vtable, size_t size)
148 /* FIXME: handle OOM */
153 HEAVY_STAT (++stat_objects_alloced);
154 if (size <= SGEN_MAX_SMALL_OBJ_SIZE)
155 HEAVY_STAT (stat_bytes_alloced += size);
157 HEAVY_STAT (stat_bytes_alloced_los += size);
159 size = ALIGN_UP (size);
161 g_assert (vtable->gc_descr);
163 if (G_UNLIKELY (has_per_allocation_action)) {
164 static int alloc_count;
165 int current_alloc = InterlockedIncrement (&alloc_count);
167 if (collect_before_allocs) {
168 if (((current_alloc % collect_before_allocs) == 0) && nursery_section) {
169 sgen_perform_collection (0, GENERATION_NURSERY, "collect-before-alloc-triggered");
170 if (!degraded_mode && sgen_can_alloc_size (size) && size <= SGEN_MAX_SMALL_OBJ_SIZE) {
172 g_assert_not_reached ();
175 } else if (verify_before_allocs) {
176 if ((current_alloc % verify_before_allocs) == 0)
177 sgen_check_whole_heap_stw ();
182 * We must already have the lock here instead of after the
183 * fast path because we might be interrupted in the fast path
184 * (after confirming that new_next < TLAB_TEMP_END) by the GC,
185 * and we'll end up allocating an object in a fragment which
186 * no longer belongs to us.
188 * The managed allocator does not do this, but it's treated
189 * specially by the world-stopping code.
192 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
193 p = sgen_los_alloc_large_inner (vtable, size);
195 /* tlab_next and tlab_temp_end are TLS vars so accessing them might be expensive */
197 p = (void**)TLAB_NEXT;
198 /* FIXME: handle overflow */
199 new_next = (char*)p + size;
200 TLAB_NEXT = new_next;
202 if (G_LIKELY (new_next < TLAB_TEMP_END)) {
206 * FIXME: We might need a memory barrier here so the change to tlab_next is
207 * visible before the vtable store.
210 DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
211 binary_protocol_alloc (p , vtable, size);
212 g_assert (*p == NULL);
213 mono_atomic_store_seq (p, vtable);
220 /* there are two cases: the object is too big or we run out of space in the TLAB */
221 /* we also reach here when the thread does its first allocation after a minor
222 * collection, since the tlab_ variables are initialized to NULL.
223 * there can be another case (from ORP), if we cooperate with the runtime a bit:
224 * objects that need finalizers can have the high bit set in their size
225 * so the above check fails and we can readily add the object to the queue.
226 * This avoids taking again the GC lock when registering, but this is moot when
227 * doing thread-local allocation, so it may not be a good idea.
229 if (TLAB_NEXT >= TLAB_REAL_END) {
230 int available_in_tlab;
232 * Run out of space in the TLAB. When this happens, some amount of space
233 * remains in the TLAB, but not enough to satisfy the current allocation
234 * request. Currently, we retire the TLAB in all cases, later we could
235 * keep it if the remaining space is above a treshold, and satisfy the
236 * allocation directly from the nursery.
239 /* when running in degraded mode, we continue allocing that way
240 * for a while, to decrease the number of useless nursery collections.
242 if (degraded_mode && degraded_mode < DEFAULT_NURSERY_SIZE) {
243 p = alloc_degraded (vtable, size, FALSE);
244 binary_protocol_alloc_degraded (p, vtable, size);
248 available_in_tlab = TLAB_REAL_END - TLAB_NEXT;
249 if (size > tlab_size || available_in_tlab > SGEN_MAX_NURSERY_WASTE) {
250 /* Allocate directly from the nursery */
252 p = sgen_nursery_alloc (size);
254 sgen_ensure_free_space (size);
256 p = alloc_degraded (vtable, size, FALSE);
257 binary_protocol_alloc_degraded (p, vtable, size);
260 p = sgen_nursery_alloc (size);
269 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION) {
273 size_t alloc_size = 0;
275 DEBUG (3, fprintf (gc_debug_file, "Retire TLAB: %p-%p [%ld]\n", TLAB_START, TLAB_REAL_END, (long)(TLAB_REAL_END - TLAB_NEXT - size)));
276 sgen_nursery_retire_region (p, available_in_tlab);
279 p = sgen_nursery_alloc_range (tlab_size, size, &alloc_size);
281 sgen_ensure_free_space (tlab_size);
283 p = alloc_degraded (vtable, size, FALSE);
284 binary_protocol_alloc_degraded (p, vtable, size);
287 p = sgen_nursery_alloc_range (tlab_size, size, &alloc_size);
297 /* Allocate a new TLAB from the current nursery fragment */
298 TLAB_START = (char*)p;
299 TLAB_NEXT = TLAB_START;
300 TLAB_REAL_END = TLAB_START + alloc_size;
301 TLAB_TEMP_END = TLAB_START + MIN (SGEN_SCAN_START_SIZE, alloc_size);
303 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION) {
304 memset (TLAB_START, 0, alloc_size);
307 /* Allocate from the TLAB */
308 p = (void*)TLAB_NEXT;
310 sgen_set_nursery_scan_start ((char*)p);
313 /* Reached tlab_temp_end */
315 /* record the scan start so we can find pinned objects more easily */
316 sgen_set_nursery_scan_start ((char*)p);
317 /* we just bump tlab_temp_end as well */
318 TLAB_TEMP_END = MIN (TLAB_REAL_END, TLAB_NEXT + SGEN_SCAN_START_SIZE);
319 DEBUG (5, fprintf (gc_debug_file, "Expanding local alloc: %p-%p\n", TLAB_NEXT, TLAB_TEMP_END));
324 DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
325 binary_protocol_alloc (p, vtable, size);
326 mono_atomic_store_seq (p, vtable);
333 mono_gc_try_alloc_obj_nolock (MonoVTable *vtable, size_t size)
339 size = ALIGN_UP (size);
341 g_assert (vtable->gc_descr);
342 if (size > SGEN_MAX_SMALL_OBJ_SIZE)
345 if (G_UNLIKELY (size > tlab_size)) {
346 /* Allocate directly from the nursery */
347 p = sgen_nursery_alloc (size);
350 sgen_set_nursery_scan_start ((char*)p);
352 /*FIXME we should use weak memory ops here. Should help specially on x86. */
353 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
356 int available_in_tlab;
358 /* tlab_next and tlab_temp_end are TLS vars so accessing them might be expensive */
360 p = (void**)TLAB_NEXT;
361 /* FIXME: handle overflow */
362 new_next = (char*)p + size;
364 real_end = TLAB_REAL_END;
365 available_in_tlab = real_end - (char*)p;
367 if (G_LIKELY (new_next < real_end)) {
368 TLAB_NEXT = new_next;
370 /* Second case, we overflowed temp end */
371 if (G_UNLIKELY (new_next >= TLAB_TEMP_END)) {
372 sgen_set_nursery_scan_start (new_next);
373 /* we just bump tlab_temp_end as well */
374 TLAB_TEMP_END = MIN (TLAB_REAL_END, TLAB_NEXT + SGEN_SCAN_START_SIZE);
375 DEBUG (5, fprintf (gc_debug_file, "Expanding local alloc: %p-%p\n", TLAB_NEXT, TLAB_TEMP_END));
377 } else if (available_in_tlab > SGEN_MAX_NURSERY_WASTE) {
378 /* Allocate directly from the nursery */
379 p = sgen_nursery_alloc (size);
383 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
386 size_t alloc_size = 0;
388 sgen_nursery_retire_region (p, available_in_tlab);
389 new_next = sgen_nursery_alloc_range (tlab_size, size, &alloc_size);
390 p = (void**)new_next;
394 TLAB_START = (char*)new_next;
395 TLAB_NEXT = new_next + size;
396 TLAB_REAL_END = new_next + alloc_size;
397 TLAB_TEMP_END = new_next + MIN (SGEN_SCAN_START_SIZE, alloc_size);
398 sgen_set_nursery_scan_start ((char*)p);
400 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
401 memset (new_next, 0, alloc_size);
405 HEAVY_STAT (++stat_objects_alloced);
406 HEAVY_STAT (stat_bytes_alloced += size);
408 DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
409 binary_protocol_alloc (p, vtable, size);
410 g_assert (*p == NULL); /* FIXME disable this in non debug builds */
412 mono_atomic_store_seq (p, vtable);
418 mono_gc_alloc_obj (MonoVTable *vtable, size_t size)
421 #ifndef DISABLE_CRITICAL_REGION
423 ENTER_CRITICAL_REGION;
424 res = mono_gc_try_alloc_obj_nolock (vtable, size);
426 EXIT_CRITICAL_REGION;
429 EXIT_CRITICAL_REGION;
432 res = mono_gc_alloc_obj_nolock (vtable, size);
434 if (G_UNLIKELY (!res))
435 return mono_gc_out_of_memory (size);
440 mono_gc_alloc_vector (MonoVTable *vtable, size_t size, uintptr_t max_length)
443 #ifndef DISABLE_CRITICAL_REGION
445 ENTER_CRITICAL_REGION;
446 arr = mono_gc_try_alloc_obj_nolock (vtable, size);
448 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
449 arr->max_length = max_length;
450 EXIT_CRITICAL_REGION;
453 EXIT_CRITICAL_REGION;
458 arr = mono_gc_alloc_obj_nolock (vtable, size);
459 if (G_UNLIKELY (!arr)) {
461 return mono_gc_out_of_memory (size);
464 arr->max_length = max_length;
472 mono_gc_alloc_array (MonoVTable *vtable, size_t size, uintptr_t max_length, uintptr_t bounds_size)
475 MonoArrayBounds *bounds;
477 #ifndef DISABLE_CRITICAL_REGION
479 ENTER_CRITICAL_REGION;
480 arr = mono_gc_try_alloc_obj_nolock (vtable, size);
482 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
483 arr->max_length = max_length;
485 bounds = (MonoArrayBounds*)((char*)arr + size - bounds_size);
486 arr->bounds = bounds;
487 EXIT_CRITICAL_REGION;
490 EXIT_CRITICAL_REGION;
495 arr = mono_gc_alloc_obj_nolock (vtable, size);
496 if (G_UNLIKELY (!arr)) {
498 return mono_gc_out_of_memory (size);
501 arr->max_length = max_length;
503 bounds = (MonoArrayBounds*)((char*)arr + size - bounds_size);
504 arr->bounds = bounds;
512 mono_gc_alloc_string (MonoVTable *vtable, size_t size, gint32 len)
515 #ifndef DISABLE_CRITICAL_REGION
517 ENTER_CRITICAL_REGION;
518 str = mono_gc_try_alloc_obj_nolock (vtable, size);
520 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
522 EXIT_CRITICAL_REGION;
525 EXIT_CRITICAL_REGION;
530 str = mono_gc_alloc_obj_nolock (vtable, size);
531 if (G_UNLIKELY (!str)) {
533 return mono_gc_out_of_memory (size);
544 * To be used for interned strings and possibly MonoThread, reflection handles.
545 * We may want to explicitly free these objects.
548 mono_gc_alloc_pinned_obj (MonoVTable *vtable, size_t size)
551 size = ALIGN_UP (size);
554 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
555 /* large objects are always pinned anyway */
556 p = sgen_los_alloc_large_inner (vtable, size);
558 DEBUG (9, g_assert (vtable->klass->inited));
559 p = major_collector.alloc_small_pinned_obj (size, SGEN_VTABLE_HAS_REFERENCES (vtable));
562 DEBUG (6, fprintf (gc_debug_file, "Allocated pinned object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
563 binary_protocol_alloc_pinned (p, vtable, size);
564 mono_atomic_store_seq (p, vtable);
571 mono_gc_alloc_mature (MonoVTable *vtable)
574 size_t size = ALIGN_UP (vtable->klass->instance_size);
576 res = alloc_degraded (vtable, size, TRUE);
577 mono_atomic_store_seq (res, vtable);
579 if (G_UNLIKELY (vtable->klass->has_finalize))
580 mono_object_register_finalizer ((MonoObject*)res);
586 mono_gc_alloc_fixed (size_t size, void *descr)
588 /* FIXME: do a single allocation */
589 void *res = calloc (1, size);
592 if (!mono_gc_register_root (res, size, descr)) {
600 mono_gc_free_fixed (void* addr)
602 mono_gc_deregister_root (addr);
607 sgen_init_tlab_info (SgenThreadInfo* info)
609 #ifndef HAVE_KW_THREAD
610 SgenThreadInfo *__thread_info__ = info;
613 info->tlab_start_addr = &TLAB_START;
614 info->tlab_next_addr = &TLAB_NEXT;
615 info->tlab_temp_end_addr = &TLAB_TEMP_END;
616 info->tlab_real_end_addr = &TLAB_REAL_END;
618 #ifdef HAVE_KW_THREAD
619 tlab_next_addr = &tlab_next;
624 * Clear the thread local TLAB variables for all threads.
627 sgen_clear_tlabs (void)
629 SgenThreadInfo *info;
631 FOREACH_THREAD (info) {
632 /* A new TLAB will be allocated when the thread does its first allocation */
633 *info->tlab_start_addr = NULL;
634 *info->tlab_next_addr = NULL;
635 *info->tlab_temp_end_addr = NULL;
636 *info->tlab_real_end_addr = NULL;
640 static MonoMethod* alloc_method_cache [ATYPE_NUM];
642 #ifdef MANAGED_ALLOCATION
643 /* FIXME: Do this in the JIT, where specialized allocation sequences can be created
644 * for each class. This is currently not easy to do, as it is hard to generate basic
645 * blocks + branches, but it is easy with the linear IL codebase.
647 * For this to work we'd need to solve the TLAB race, first. Now we
648 * require the allocator to be in a few known methods to make sure
649 * that they are executed atomically via the restart mechanism.
652 create_allocator (int atype)
655 guint32 slowpath_branch, max_size_branch;
656 MonoMethodBuilder *mb;
658 MonoMethodSignature *csig;
659 static gboolean registered = FALSE;
660 int tlab_next_addr_var, new_next_var;
662 const char *name = NULL;
663 AllocatorWrapperInfo *info;
665 #ifdef HAVE_KW_THREAD
666 int tlab_next_addr_offset = -1;
667 int tlab_temp_end_offset = -1;
669 MONO_THREAD_VAR_OFFSET (tlab_next_addr, tlab_next_addr_offset);
670 MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
672 g_assert (tlab_next_addr_offset != -1);
673 g_assert (tlab_temp_end_offset != -1);
677 mono_register_jit_icall (mono_gc_alloc_obj, "mono_gc_alloc_obj", mono_create_icall_signature ("object ptr int"), FALSE);
678 mono_register_jit_icall (mono_gc_alloc_vector, "mono_gc_alloc_vector", mono_create_icall_signature ("object ptr int int"), FALSE);
682 if (atype == ATYPE_SMALL) {
685 } else if (atype == ATYPE_NORMAL) {
688 } else if (atype == ATYPE_VECTOR) {
690 name = "AllocVector";
692 g_assert_not_reached ();
695 csig = mono_metadata_signature_alloc (mono_defaults.corlib, num_params);
696 csig->ret = &mono_defaults.object_class->byval_arg;
697 for (i = 0; i < num_params; ++i)
698 csig->params [i] = &mono_defaults.int_class->byval_arg;
700 mb = mono_mb_new (mono_defaults.object_class, name, MONO_WRAPPER_ALLOC);
701 size_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
702 if (atype == ATYPE_NORMAL || atype == ATYPE_SMALL) {
703 /* size = vtable->klass->instance_size; */
704 mono_mb_emit_ldarg (mb, 0);
705 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass));
706 mono_mb_emit_byte (mb, CEE_ADD);
707 mono_mb_emit_byte (mb, CEE_LDIND_I);
708 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, instance_size));
709 mono_mb_emit_byte (mb, CEE_ADD);
710 /* FIXME: assert instance_size stays a 4 byte integer */
711 mono_mb_emit_byte (mb, CEE_LDIND_U4);
712 mono_mb_emit_stloc (mb, size_var);
713 } else if (atype == ATYPE_VECTOR) {
714 MonoExceptionClause *clause;
716 MonoClass *oom_exc_class;
719 /* n > MONO_ARRAY_MAX_INDEX -> OverflowException */
720 mono_mb_emit_ldarg (mb, 1);
721 mono_mb_emit_icon (mb, MONO_ARRAY_MAX_INDEX);
722 pos = mono_mb_emit_short_branch (mb, CEE_BLE_UN_S);
723 mono_mb_emit_exception (mb, "OverflowException", NULL);
724 mono_mb_patch_short_branch (mb, pos);
726 clause = mono_image_alloc0 (mono_defaults.corlib, sizeof (MonoExceptionClause));
727 clause->try_offset = mono_mb_get_label (mb);
729 /* vtable->klass->sizes.element_size */
730 mono_mb_emit_ldarg (mb, 0);
731 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass));
732 mono_mb_emit_byte (mb, CEE_ADD);
733 mono_mb_emit_byte (mb, CEE_LDIND_I);
734 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, sizes.element_size));
735 mono_mb_emit_byte (mb, CEE_ADD);
736 mono_mb_emit_byte (mb, CEE_LDIND_U4);
739 mono_mb_emit_ldarg (mb, 1);
740 mono_mb_emit_byte (mb, CEE_MUL_OVF_UN);
741 /* + sizeof (MonoArray) */
742 mono_mb_emit_icon (mb, sizeof (MonoArray));
743 mono_mb_emit_byte (mb, CEE_ADD_OVF_UN);
744 mono_mb_emit_stloc (mb, size_var);
746 pos_leave = mono_mb_emit_branch (mb, CEE_LEAVE);
749 clause->flags = MONO_EXCEPTION_CLAUSE_NONE;
750 clause->try_len = mono_mb_get_pos (mb) - clause->try_offset;
751 clause->data.catch_class = mono_class_from_name (mono_defaults.corlib,
752 "System", "OverflowException");
753 g_assert (clause->data.catch_class);
754 clause->handler_offset = mono_mb_get_label (mb);
756 oom_exc_class = mono_class_from_name (mono_defaults.corlib,
757 "System", "OutOfMemoryException");
758 g_assert (oom_exc_class);
759 ctor = mono_class_get_method_from_name (oom_exc_class, ".ctor", 0);
762 mono_mb_emit_byte (mb, CEE_POP);
763 mono_mb_emit_op (mb, CEE_NEWOBJ, ctor);
764 mono_mb_emit_byte (mb, CEE_THROW);
766 clause->handler_len = mono_mb_get_pos (mb) - clause->handler_offset;
767 mono_mb_set_clauses (mb, 1, clause);
768 mono_mb_patch_branch (mb, pos_leave);
771 g_assert_not_reached ();
774 /* size += ALLOC_ALIGN - 1; */
775 mono_mb_emit_ldloc (mb, size_var);
776 mono_mb_emit_icon (mb, ALLOC_ALIGN - 1);
777 mono_mb_emit_byte (mb, CEE_ADD);
778 /* size &= ~(ALLOC_ALIGN - 1); */
779 mono_mb_emit_icon (mb, ~(ALLOC_ALIGN - 1));
780 mono_mb_emit_byte (mb, CEE_AND);
781 mono_mb_emit_stloc (mb, size_var);
783 /* if (size > MAX_SMALL_OBJ_SIZE) goto slowpath */
784 if (atype != ATYPE_SMALL) {
785 mono_mb_emit_ldloc (mb, size_var);
786 mono_mb_emit_icon (mb, MAX_SMALL_OBJ_SIZE);
787 max_size_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S);
791 * We need to modify tlab_next, but the JIT only supports reading, so we read
792 * another tls var holding its address instead.
795 /* tlab_next_addr (local) = tlab_next_addr (TLS var) */
796 tlab_next_addr_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
797 EMIT_TLS_ACCESS (mb, tlab_next_addr, tlab_next_addr_offset);
798 mono_mb_emit_stloc (mb, tlab_next_addr_var);
800 /* p = (void**)tlab_next; */
801 p_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
802 mono_mb_emit_ldloc (mb, tlab_next_addr_var);
803 mono_mb_emit_byte (mb, CEE_LDIND_I);
804 mono_mb_emit_stloc (mb, p_var);
806 /* new_next = (char*)p + size; */
807 new_next_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
808 mono_mb_emit_ldloc (mb, p_var);
809 mono_mb_emit_ldloc (mb, size_var);
810 mono_mb_emit_byte (mb, CEE_CONV_I);
811 mono_mb_emit_byte (mb, CEE_ADD);
812 mono_mb_emit_stloc (mb, new_next_var);
814 /* if (G_LIKELY (new_next < tlab_temp_end)) */
815 mono_mb_emit_ldloc (mb, new_next_var);
816 EMIT_TLS_ACCESS (mb, tlab_temp_end, tlab_temp_end_offset);
817 slowpath_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
820 if (atype != ATYPE_SMALL)
821 mono_mb_patch_short_branch (mb, max_size_branch);
823 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
824 mono_mb_emit_byte (mb, CEE_MONO_NOT_TAKEN);
826 /* FIXME: mono_gc_alloc_obj takes a 'size_t' as an argument, not an int32 */
827 mono_mb_emit_ldarg (mb, 0);
828 mono_mb_emit_ldloc (mb, size_var);
829 if (atype == ATYPE_NORMAL || atype == ATYPE_SMALL) {
830 mono_mb_emit_icall (mb, mono_gc_alloc_obj);
831 } else if (atype == ATYPE_VECTOR) {
832 mono_mb_emit_ldarg (mb, 1);
833 mono_mb_emit_icall (mb, mono_gc_alloc_vector);
835 g_assert_not_reached ();
837 mono_mb_emit_byte (mb, CEE_RET);
840 mono_mb_patch_short_branch (mb, slowpath_branch);
842 /* FIXME: Memory barrier */
844 /* tlab_next = new_next */
845 mono_mb_emit_ldloc (mb, tlab_next_addr_var);
846 mono_mb_emit_ldloc (mb, new_next_var);
847 mono_mb_emit_byte (mb, CEE_STIND_I);
849 /*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. */
850 mono_mb_emit_byte ((mb), MONO_CUSTOM_PREFIX);
851 mono_mb_emit_op (mb, CEE_MONO_MEMORY_BARRIER, StoreStoreBarrier);
854 mono_mb_emit_ldloc (mb, p_var);
855 mono_mb_emit_ldarg (mb, 0);
856 mono_mb_emit_byte (mb, CEE_STIND_I);
858 if (atype == ATYPE_VECTOR) {
859 /* arr->max_length = max_length; */
860 mono_mb_emit_ldloc (mb, p_var);
861 mono_mb_emit_ldflda (mb, G_STRUCT_OFFSET (MonoArray, max_length));
862 mono_mb_emit_ldarg (mb, 1);
863 #ifdef MONO_BIG_ARRAYS
864 mono_mb_emit_byte (mb, CEE_STIND_I);
866 mono_mb_emit_byte (mb, CEE_STIND_I4);
871 We must make sure both vtable and max_length are globaly visible before returning to managed land.
873 mono_mb_emit_byte ((mb), MONO_CUSTOM_PREFIX);
874 mono_mb_emit_op (mb, CEE_MONO_MEMORY_BARRIER, StoreStoreBarrier);
877 mono_mb_emit_ldloc (mb, p_var);
878 mono_mb_emit_byte (mb, CEE_RET);
880 res = mono_mb_create_method (mb, csig, 8);
882 mono_method_get_header (res)->init_locals = FALSE;
884 info = mono_image_alloc0 (mono_defaults.corlib, sizeof (AllocatorWrapperInfo));
885 info->gc_name = "sgen";
886 info->alloc_type = atype;
887 mono_marshal_set_wrapper_info (res, info);
894 * Generate an allocator method implementing the fast path of mono_gc_alloc_obj ().
895 * The signature of the called method is:
896 * object allocate (MonoVTable *vtable)
899 mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box)
901 #ifdef MANAGED_ALLOCATION
902 MonoClass *klass = vtable->klass;
904 #ifdef HAVE_KW_THREAD
905 int tlab_next_offset = -1;
906 int tlab_temp_end_offset = -1;
907 MONO_THREAD_VAR_OFFSET (tlab_next, tlab_next_offset);
908 MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
910 if (tlab_next_offset == -1 || tlab_temp_end_offset == -1)
914 if (!mono_runtime_has_tls_get ())
916 if (klass->instance_size > tlab_size)
918 if (klass->has_finalize || klass->marshalbyref || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS))
922 if (klass->byval_arg.type == MONO_TYPE_STRING)
924 if (collect_before_allocs)
927 if (ALIGN_TO (klass->instance_size, ALLOC_ALIGN) < MAX_SMALL_OBJ_SIZE)
928 return mono_gc_get_managed_allocator_by_type (ATYPE_SMALL);
930 return mono_gc_get_managed_allocator_by_type (ATYPE_NORMAL);
937 mono_gc_get_managed_array_allocator (MonoVTable *vtable, int rank)
939 #ifdef MANAGED_ALLOCATION
940 MonoClass *klass = vtable->klass;
942 #ifdef HAVE_KW_THREAD
943 int tlab_next_offset = -1;
944 int tlab_temp_end_offset = -1;
945 MONO_THREAD_VAR_OFFSET (tlab_next, tlab_next_offset);
946 MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
948 if (tlab_next_offset == -1 || tlab_temp_end_offset == -1)
954 if (!mono_runtime_has_tls_get ())
956 if (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS)
958 if (has_per_allocation_action)
960 g_assert (!mono_class_has_finalizer (klass) && !klass->marshalbyref);
962 return mono_gc_get_managed_allocator_by_type (ATYPE_VECTOR);
969 mono_gc_get_managed_allocator_by_type (int atype)
971 #ifdef MANAGED_ALLOCATION
974 if (!mono_runtime_has_tls_get ())
978 res = alloc_method_cache [atype];
980 res = alloc_method_cache [atype] = create_allocator (atype);
981 mono_loader_unlock ();
989 mono_gc_get_managed_allocator_types (void)
995 sgen_is_managed_allocator (MonoMethod *method)
999 for (i = 0; i < ATYPE_NUM; ++i)
1000 if (method == alloc_method_cache [i])
1005 #ifdef HEAVY_STATISTICS
1007 sgen_alloc_init_heavy_stats (void)
1009 mono_counters_register ("# objects allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced);
1010 mono_counters_register ("bytes allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced);
1011 mono_counters_register ("bytes allocated in LOS", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_los);
1015 #endif /*HAVE_SGEN_GC*/