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;
123 if (last_major_gc_warned < stat_major_gcs) {
125 if (num_degraded == 1 || num_degraded == 3)
126 fprintf (stderr, "Warning: Degraded allocation. Consider increasing nursery-size if the warning persists.\n");
127 else if (num_degraded == 10)
128 fprintf (stderr, "Warning: Repeated degraded allocation. Consider increasing nursery-size.\n");
129 last_major_gc_warned = stat_major_gcs;
131 InterlockedExchangeAdd (°raded_mode, size);
132 sgen_ensure_free_space (size);
134 if (sgen_need_major_collection (size))
135 sgen_perform_collection (size, GENERATION_OLD, "mature allocation failure");
139 p = major_collector.alloc_degraded (vtable, size);
142 MONO_GC_MAJOR_OBJ_ALLOC_MATURE ((mword)p, size, vtable->klass->name_space, vtable->klass->name);
144 binary_protocol_alloc_degraded (p, vtable, size);
145 MONO_GC_MAJOR_OBJ_ALLOC_DEGRADED ((mword)p, size, vtable->klass->name_space, vtable->klass->name);
152 * Provide a variant that takes just the vtable for small fixed-size objects.
153 * The aligned size is already computed and stored in vt->gc_descr.
154 * Note: every SGEN_SCAN_START_SIZE or so we are given the chance to do some special
155 * processing. We can keep track of where objects start, for example,
156 * so when we scan the thread stacks for pinned objects, we can start
157 * a search for the pinned object in SGEN_SCAN_START_SIZE chunks.
160 mono_gc_alloc_obj_nolock (MonoVTable *vtable, size_t size)
162 /* FIXME: handle OOM */
167 HEAVY_STAT (++stat_objects_alloced);
168 if (size <= SGEN_MAX_SMALL_OBJ_SIZE)
169 HEAVY_STAT (stat_bytes_alloced += size);
171 HEAVY_STAT (stat_bytes_alloced_los += size);
173 size = ALIGN_UP (size);
175 g_assert (vtable->gc_descr);
177 if (G_UNLIKELY (has_per_allocation_action)) {
178 static int alloc_count;
179 int current_alloc = InterlockedIncrement (&alloc_count);
181 if (collect_before_allocs) {
182 if (((current_alloc % collect_before_allocs) == 0) && nursery_section) {
183 sgen_perform_collection (0, GENERATION_NURSERY, "collect-before-alloc-triggered");
184 if (!degraded_mode && sgen_can_alloc_size (size) && size <= SGEN_MAX_SMALL_OBJ_SIZE) {
186 g_assert_not_reached ();
189 } else if (verify_before_allocs) {
190 if ((current_alloc % verify_before_allocs) == 0)
191 sgen_check_whole_heap_stw ();
196 * We must already have the lock here instead of after the
197 * fast path because we might be interrupted in the fast path
198 * (after confirming that new_next < TLAB_TEMP_END) by the GC,
199 * and we'll end up allocating an object in a fragment which
200 * no longer belongs to us.
202 * The managed allocator does not do this, but it's treated
203 * specially by the world-stopping code.
206 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
207 p = sgen_los_alloc_large_inner (vtable, size);
209 /* tlab_next and tlab_temp_end are TLS vars so accessing them might be expensive */
211 p = (void**)TLAB_NEXT;
212 /* FIXME: handle overflow */
213 new_next = (char*)p + size;
214 TLAB_NEXT = new_next;
216 if (G_LIKELY (new_next < TLAB_TEMP_END)) {
220 * FIXME: We might need a memory barrier here so the change to tlab_next is
221 * visible before the vtable store.
224 DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
225 binary_protocol_alloc (p , vtable, size);
226 if (G_UNLIKELY (MONO_GC_NURSERY_OBJ_ALLOC_ENABLED ()))
227 MONO_GC_NURSERY_OBJ_ALLOC ((mword)p, size, vtable->klass->name_space, vtable->klass->name);
228 g_assert (*p == NULL);
229 mono_atomic_store_seq (p, vtable);
236 /* there are two cases: the object is too big or we run out of space in the TLAB */
237 /* we also reach here when the thread does its first allocation after a minor
238 * collection, since the tlab_ variables are initialized to NULL.
239 * there can be another case (from ORP), if we cooperate with the runtime a bit:
240 * objects that need finalizers can have the high bit set in their size
241 * so the above check fails and we can readily add the object to the queue.
242 * This avoids taking again the GC lock when registering, but this is moot when
243 * doing thread-local allocation, so it may not be a good idea.
245 if (TLAB_NEXT >= TLAB_REAL_END) {
246 int available_in_tlab;
248 * Run out of space in the TLAB. When this happens, some amount of space
249 * remains in the TLAB, but not enough to satisfy the current allocation
250 * request. Currently, we retire the TLAB in all cases, later we could
251 * keep it if the remaining space is above a treshold, and satisfy the
252 * allocation directly from the nursery.
255 /* when running in degraded mode, we continue allocing that way
256 * for a while, to decrease the number of useless nursery collections.
258 if (degraded_mode && degraded_mode < DEFAULT_NURSERY_SIZE)
259 return alloc_degraded (vtable, size, FALSE);
261 available_in_tlab = TLAB_REAL_END - TLAB_NEXT;
262 if (size > tlab_size || available_in_tlab > SGEN_MAX_NURSERY_WASTE) {
263 /* Allocate directly from the nursery */
265 p = sgen_nursery_alloc (size);
267 sgen_ensure_free_space (size);
269 return alloc_degraded (vtable, size, FALSE);
271 p = sgen_nursery_alloc (size);
279 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION) {
283 size_t alloc_size = 0;
285 DEBUG (3, fprintf (gc_debug_file, "Retire TLAB: %p-%p [%ld]\n", TLAB_START, TLAB_REAL_END, (long)(TLAB_REAL_END - TLAB_NEXT - size)));
286 sgen_nursery_retire_region (p, available_in_tlab);
289 p = sgen_nursery_alloc_range (tlab_size, size, &alloc_size);
291 sgen_ensure_free_space (tlab_size);
293 return alloc_degraded (vtable, size, FALSE);
295 p = sgen_nursery_alloc_range (tlab_size, size, &alloc_size);
304 /* Allocate a new TLAB from the current nursery fragment */
305 TLAB_START = (char*)p;
306 TLAB_NEXT = TLAB_START;
307 TLAB_REAL_END = TLAB_START + alloc_size;
308 TLAB_TEMP_END = TLAB_START + MIN (SGEN_SCAN_START_SIZE, alloc_size);
310 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION) {
311 memset (TLAB_START, 0, alloc_size);
314 /* Allocate from the TLAB */
315 p = (void*)TLAB_NEXT;
317 sgen_set_nursery_scan_start ((char*)p);
320 /* Reached tlab_temp_end */
322 /* record the scan start so we can find pinned objects more easily */
323 sgen_set_nursery_scan_start ((char*)p);
324 /* we just bump tlab_temp_end as well */
325 TLAB_TEMP_END = MIN (TLAB_REAL_END, TLAB_NEXT + SGEN_SCAN_START_SIZE);
326 DEBUG (5, fprintf (gc_debug_file, "Expanding local alloc: %p-%p\n", TLAB_NEXT, TLAB_TEMP_END));
331 DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
332 binary_protocol_alloc (p, vtable, size);
333 if (G_UNLIKELY (MONO_GC_MAJOR_OBJ_ALLOC_LARGE_ENABLED ()|| MONO_GC_NURSERY_OBJ_ALLOC_ENABLED ())) {
334 if (size > SGEN_MAX_SMALL_OBJ_SIZE)
335 MONO_GC_MAJOR_OBJ_ALLOC_LARGE ((mword)p, size, vtable->klass->name_space, vtable->klass->name);
337 MONO_GC_NURSERY_OBJ_ALLOC ((mword)p, size, vtable->klass->name_space, vtable->klass->name);
339 mono_atomic_store_seq (p, vtable);
346 mono_gc_try_alloc_obj_nolock (MonoVTable *vtable, size_t size)
352 size = ALIGN_UP (size);
354 g_assert (vtable->gc_descr);
355 if (size > SGEN_MAX_SMALL_OBJ_SIZE)
358 if (G_UNLIKELY (size > tlab_size)) {
359 /* Allocate directly from the nursery */
360 p = sgen_nursery_alloc (size);
363 sgen_set_nursery_scan_start ((char*)p);
365 /*FIXME we should use weak memory ops here. Should help specially on x86. */
366 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
369 int available_in_tlab;
371 /* tlab_next and tlab_temp_end are TLS vars so accessing them might be expensive */
373 p = (void**)TLAB_NEXT;
374 /* FIXME: handle overflow */
375 new_next = (char*)p + size;
377 real_end = TLAB_REAL_END;
378 available_in_tlab = real_end - (char*)p;
380 if (G_LIKELY (new_next < real_end)) {
381 TLAB_NEXT = new_next;
383 /* Second case, we overflowed temp end */
384 if (G_UNLIKELY (new_next >= TLAB_TEMP_END)) {
385 sgen_set_nursery_scan_start (new_next);
386 /* we just bump tlab_temp_end as well */
387 TLAB_TEMP_END = MIN (TLAB_REAL_END, TLAB_NEXT + SGEN_SCAN_START_SIZE);
388 DEBUG (5, fprintf (gc_debug_file, "Expanding local alloc: %p-%p\n", TLAB_NEXT, TLAB_TEMP_END));
390 } else if (available_in_tlab > SGEN_MAX_NURSERY_WASTE) {
391 /* Allocate directly from the nursery */
392 p = sgen_nursery_alloc (size);
396 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
399 size_t alloc_size = 0;
401 sgen_nursery_retire_region (p, available_in_tlab);
402 new_next = sgen_nursery_alloc_range (tlab_size, size, &alloc_size);
403 p = (void**)new_next;
407 TLAB_START = (char*)new_next;
408 TLAB_NEXT = new_next + size;
409 TLAB_REAL_END = new_next + alloc_size;
410 TLAB_TEMP_END = new_next + MIN (SGEN_SCAN_START_SIZE, alloc_size);
411 sgen_set_nursery_scan_start ((char*)p);
413 if (nursery_clear_policy == CLEAR_AT_TLAB_CREATION)
414 memset (new_next, 0, alloc_size);
416 MONO_GC_NURSERY_TLAB_ALLOC ((mword)new_next, alloc_size);
420 HEAVY_STAT (++stat_objects_alloced);
421 HEAVY_STAT (stat_bytes_alloced += size);
423 DEBUG (6, fprintf (gc_debug_file, "Allocated object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
424 binary_protocol_alloc (p, vtable, size);
425 if (G_UNLIKELY (MONO_GC_NURSERY_OBJ_ALLOC_ENABLED ()))
426 MONO_GC_NURSERY_OBJ_ALLOC ((mword)p, size, vtable->klass->name_space, vtable->klass->name);
427 g_assert (*p == NULL); /* FIXME disable this in non debug builds */
429 mono_atomic_store_seq (p, vtable);
435 mono_gc_alloc_obj (MonoVTable *vtable, size_t size)
438 #ifndef DISABLE_CRITICAL_REGION
440 ENTER_CRITICAL_REGION;
441 res = mono_gc_try_alloc_obj_nolock (vtable, size);
443 EXIT_CRITICAL_REGION;
446 EXIT_CRITICAL_REGION;
449 res = mono_gc_alloc_obj_nolock (vtable, size);
451 if (G_UNLIKELY (!res))
452 return mono_gc_out_of_memory (size);
457 mono_gc_alloc_vector (MonoVTable *vtable, size_t size, uintptr_t max_length)
460 #ifndef DISABLE_CRITICAL_REGION
462 ENTER_CRITICAL_REGION;
463 arr = mono_gc_try_alloc_obj_nolock (vtable, size);
465 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
466 arr->max_length = max_length;
467 EXIT_CRITICAL_REGION;
470 EXIT_CRITICAL_REGION;
475 arr = mono_gc_alloc_obj_nolock (vtable, size);
476 if (G_UNLIKELY (!arr)) {
478 return mono_gc_out_of_memory (size);
481 arr->max_length = max_length;
489 mono_gc_alloc_array (MonoVTable *vtable, size_t size, uintptr_t max_length, uintptr_t bounds_size)
492 MonoArrayBounds *bounds;
494 #ifndef DISABLE_CRITICAL_REGION
496 ENTER_CRITICAL_REGION;
497 arr = mono_gc_try_alloc_obj_nolock (vtable, size);
499 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
500 arr->max_length = max_length;
502 bounds = (MonoArrayBounds*)((char*)arr + size - bounds_size);
503 arr->bounds = bounds;
504 EXIT_CRITICAL_REGION;
507 EXIT_CRITICAL_REGION;
512 arr = mono_gc_alloc_obj_nolock (vtable, size);
513 if (G_UNLIKELY (!arr)) {
515 return mono_gc_out_of_memory (size);
518 arr->max_length = max_length;
520 bounds = (MonoArrayBounds*)((char*)arr + size - bounds_size);
521 arr->bounds = bounds;
529 mono_gc_alloc_string (MonoVTable *vtable, size_t size, gint32 len)
532 #ifndef DISABLE_CRITICAL_REGION
534 ENTER_CRITICAL_REGION;
535 str = mono_gc_try_alloc_obj_nolock (vtable, size);
537 /*This doesn't require fencing since EXIT_CRITICAL_REGION already does it for us*/
539 EXIT_CRITICAL_REGION;
542 EXIT_CRITICAL_REGION;
547 str = mono_gc_alloc_obj_nolock (vtable, size);
548 if (G_UNLIKELY (!str)) {
550 return mono_gc_out_of_memory (size);
561 * To be used for interned strings and possibly MonoThread, reflection handles.
562 * We may want to explicitly free these objects.
565 mono_gc_alloc_pinned_obj (MonoVTable *vtable, size_t size)
568 size = ALIGN_UP (size);
571 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
572 /* large objects are always pinned anyway */
573 p = sgen_los_alloc_large_inner (vtable, size);
575 DEBUG (9, g_assert (vtable->klass->inited));
576 p = major_collector.alloc_small_pinned_obj (size, SGEN_VTABLE_HAS_REFERENCES (vtable));
579 DEBUG (6, fprintf (gc_debug_file, "Allocated pinned object %p, vtable: %p (%s), size: %zd\n", p, vtable, vtable->klass->name, size));
580 if (size > SGEN_MAX_SMALL_OBJ_SIZE)
581 MONO_GC_MAJOR_OBJ_ALLOC_LARGE ((mword)p, size, vtable->klass->name_space, vtable->klass->name);
583 MONO_GC_MAJOR_OBJ_ALLOC_PINNED ((mword)p, size, vtable->klass->name_space, vtable->klass->name);
584 binary_protocol_alloc_pinned (p, vtable, size);
585 mono_atomic_store_seq (p, vtable);
592 mono_gc_alloc_mature (MonoVTable *vtable)
595 size_t size = ALIGN_UP (vtable->klass->instance_size);
597 res = alloc_degraded (vtable, size, TRUE);
598 mono_atomic_store_seq (res, vtable);
600 if (G_UNLIKELY (vtable->klass->has_finalize))
601 mono_object_register_finalizer ((MonoObject*)res);
607 mono_gc_alloc_fixed (size_t size, void *descr)
609 /* FIXME: do a single allocation */
610 void *res = calloc (1, size);
613 if (!mono_gc_register_root (res, size, descr)) {
621 mono_gc_free_fixed (void* addr)
623 mono_gc_deregister_root (addr);
628 sgen_init_tlab_info (SgenThreadInfo* info)
630 #ifndef HAVE_KW_THREAD
631 SgenThreadInfo *__thread_info__ = info;
634 info->tlab_start_addr = &TLAB_START;
635 info->tlab_next_addr = &TLAB_NEXT;
636 info->tlab_temp_end_addr = &TLAB_TEMP_END;
637 info->tlab_real_end_addr = &TLAB_REAL_END;
639 #ifdef HAVE_KW_THREAD
640 tlab_next_addr = &tlab_next;
645 * Clear the thread local TLAB variables for all threads.
648 sgen_clear_tlabs (void)
650 SgenThreadInfo *info;
652 FOREACH_THREAD (info) {
653 /* A new TLAB will be allocated when the thread does its first allocation */
654 *info->tlab_start_addr = NULL;
655 *info->tlab_next_addr = NULL;
656 *info->tlab_temp_end_addr = NULL;
657 *info->tlab_real_end_addr = NULL;
661 static MonoMethod* alloc_method_cache [ATYPE_NUM];
663 #ifdef MANAGED_ALLOCATION
664 /* FIXME: Do this in the JIT, where specialized allocation sequences can be created
665 * for each class. This is currently not easy to do, as it is hard to generate basic
666 * blocks + branches, but it is easy with the linear IL codebase.
668 * For this to work we'd need to solve the TLAB race, first. Now we
669 * require the allocator to be in a few known methods to make sure
670 * that they are executed atomically via the restart mechanism.
673 create_allocator (int atype)
676 guint32 slowpath_branch, max_size_branch;
677 MonoMethodBuilder *mb;
679 MonoMethodSignature *csig;
680 static gboolean registered = FALSE;
681 int tlab_next_addr_var, new_next_var;
683 const char *name = NULL;
684 AllocatorWrapperInfo *info;
686 #ifdef HAVE_KW_THREAD
687 int tlab_next_addr_offset = -1;
688 int tlab_temp_end_offset = -1;
690 MONO_THREAD_VAR_OFFSET (tlab_next_addr, tlab_next_addr_offset);
691 MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
693 g_assert (tlab_next_addr_offset != -1);
694 g_assert (tlab_temp_end_offset != -1);
698 mono_register_jit_icall (mono_gc_alloc_obj, "mono_gc_alloc_obj", mono_create_icall_signature ("object ptr int"), FALSE);
699 mono_register_jit_icall (mono_gc_alloc_vector, "mono_gc_alloc_vector", mono_create_icall_signature ("object ptr int int"), FALSE);
703 if (atype == ATYPE_SMALL) {
706 } else if (atype == ATYPE_NORMAL) {
709 } else if (atype == ATYPE_VECTOR) {
711 name = "AllocVector";
713 g_assert_not_reached ();
716 csig = mono_metadata_signature_alloc (mono_defaults.corlib, num_params);
717 csig->ret = &mono_defaults.object_class->byval_arg;
718 for (i = 0; i < num_params; ++i)
719 csig->params [i] = &mono_defaults.int_class->byval_arg;
721 mb = mono_mb_new (mono_defaults.object_class, name, MONO_WRAPPER_ALLOC);
722 size_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
723 if (atype == ATYPE_NORMAL || atype == ATYPE_SMALL) {
724 /* size = vtable->klass->instance_size; */
725 mono_mb_emit_ldarg (mb, 0);
726 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass));
727 mono_mb_emit_byte (mb, CEE_ADD);
728 mono_mb_emit_byte (mb, CEE_LDIND_I);
729 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, instance_size));
730 mono_mb_emit_byte (mb, CEE_ADD);
731 /* FIXME: assert instance_size stays a 4 byte integer */
732 mono_mb_emit_byte (mb, CEE_LDIND_U4);
733 mono_mb_emit_stloc (mb, size_var);
734 } else if (atype == ATYPE_VECTOR) {
735 MonoExceptionClause *clause;
737 MonoClass *oom_exc_class;
740 /* n > MONO_ARRAY_MAX_INDEX -> OverflowException */
741 mono_mb_emit_ldarg (mb, 1);
742 mono_mb_emit_icon (mb, MONO_ARRAY_MAX_INDEX);
743 pos = mono_mb_emit_short_branch (mb, CEE_BLE_UN_S);
744 mono_mb_emit_exception (mb, "OverflowException", NULL);
745 mono_mb_patch_short_branch (mb, pos);
747 clause = mono_image_alloc0 (mono_defaults.corlib, sizeof (MonoExceptionClause));
748 clause->try_offset = mono_mb_get_label (mb);
750 /* vtable->klass->sizes.element_size */
751 mono_mb_emit_ldarg (mb, 0);
752 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass));
753 mono_mb_emit_byte (mb, CEE_ADD);
754 mono_mb_emit_byte (mb, CEE_LDIND_I);
755 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, sizes.element_size));
756 mono_mb_emit_byte (mb, CEE_ADD);
757 mono_mb_emit_byte (mb, CEE_LDIND_U4);
760 mono_mb_emit_ldarg (mb, 1);
761 mono_mb_emit_byte (mb, CEE_MUL_OVF_UN);
762 /* + sizeof (MonoArray) */
763 mono_mb_emit_icon (mb, sizeof (MonoArray));
764 mono_mb_emit_byte (mb, CEE_ADD_OVF_UN);
765 mono_mb_emit_stloc (mb, size_var);
767 pos_leave = mono_mb_emit_branch (mb, CEE_LEAVE);
770 clause->flags = MONO_EXCEPTION_CLAUSE_NONE;
771 clause->try_len = mono_mb_get_pos (mb) - clause->try_offset;
772 clause->data.catch_class = mono_class_from_name (mono_defaults.corlib,
773 "System", "OverflowException");
774 g_assert (clause->data.catch_class);
775 clause->handler_offset = mono_mb_get_label (mb);
777 oom_exc_class = mono_class_from_name (mono_defaults.corlib,
778 "System", "OutOfMemoryException");
779 g_assert (oom_exc_class);
780 ctor = mono_class_get_method_from_name (oom_exc_class, ".ctor", 0);
783 mono_mb_emit_byte (mb, CEE_POP);
784 mono_mb_emit_op (mb, CEE_NEWOBJ, ctor);
785 mono_mb_emit_byte (mb, CEE_THROW);
787 clause->handler_len = mono_mb_get_pos (mb) - clause->handler_offset;
788 mono_mb_set_clauses (mb, 1, clause);
789 mono_mb_patch_branch (mb, pos_leave);
792 g_assert_not_reached ();
795 /* size += ALLOC_ALIGN - 1; */
796 mono_mb_emit_ldloc (mb, size_var);
797 mono_mb_emit_icon (mb, ALLOC_ALIGN - 1);
798 mono_mb_emit_byte (mb, CEE_ADD);
799 /* size &= ~(ALLOC_ALIGN - 1); */
800 mono_mb_emit_icon (mb, ~(ALLOC_ALIGN - 1));
801 mono_mb_emit_byte (mb, CEE_AND);
802 mono_mb_emit_stloc (mb, size_var);
804 /* if (size > MAX_SMALL_OBJ_SIZE) goto slowpath */
805 if (atype != ATYPE_SMALL) {
806 mono_mb_emit_ldloc (mb, size_var);
807 mono_mb_emit_icon (mb, MAX_SMALL_OBJ_SIZE);
808 max_size_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S);
812 * We need to modify tlab_next, but the JIT only supports reading, so we read
813 * another tls var holding its address instead.
816 /* tlab_next_addr (local) = tlab_next_addr (TLS var) */
817 tlab_next_addr_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
818 EMIT_TLS_ACCESS (mb, tlab_next_addr, tlab_next_addr_offset);
819 mono_mb_emit_stloc (mb, tlab_next_addr_var);
821 /* p = (void**)tlab_next; */
822 p_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
823 mono_mb_emit_ldloc (mb, tlab_next_addr_var);
824 mono_mb_emit_byte (mb, CEE_LDIND_I);
825 mono_mb_emit_stloc (mb, p_var);
827 /* new_next = (char*)p + size; */
828 new_next_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
829 mono_mb_emit_ldloc (mb, p_var);
830 mono_mb_emit_ldloc (mb, size_var);
831 mono_mb_emit_byte (mb, CEE_CONV_I);
832 mono_mb_emit_byte (mb, CEE_ADD);
833 mono_mb_emit_stloc (mb, new_next_var);
835 /* if (G_LIKELY (new_next < tlab_temp_end)) */
836 mono_mb_emit_ldloc (mb, new_next_var);
837 EMIT_TLS_ACCESS (mb, tlab_temp_end, tlab_temp_end_offset);
838 slowpath_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
841 if (atype != ATYPE_SMALL)
842 mono_mb_patch_short_branch (mb, max_size_branch);
844 mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
845 mono_mb_emit_byte (mb, CEE_MONO_NOT_TAKEN);
847 /* FIXME: mono_gc_alloc_obj takes a 'size_t' as an argument, not an int32 */
848 mono_mb_emit_ldarg (mb, 0);
849 mono_mb_emit_ldloc (mb, size_var);
850 if (atype == ATYPE_NORMAL || atype == ATYPE_SMALL) {
851 mono_mb_emit_icall (mb, mono_gc_alloc_obj);
852 } else if (atype == ATYPE_VECTOR) {
853 mono_mb_emit_ldarg (mb, 1);
854 mono_mb_emit_icall (mb, mono_gc_alloc_vector);
856 g_assert_not_reached ();
858 mono_mb_emit_byte (mb, CEE_RET);
861 mono_mb_patch_short_branch (mb, slowpath_branch);
863 /* FIXME: Memory barrier */
865 /* tlab_next = new_next */
866 mono_mb_emit_ldloc (mb, tlab_next_addr_var);
867 mono_mb_emit_ldloc (mb, new_next_var);
868 mono_mb_emit_byte (mb, CEE_STIND_I);
870 /*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. */
871 mono_mb_emit_byte ((mb), MONO_CUSTOM_PREFIX);
872 mono_mb_emit_op (mb, CEE_MONO_MEMORY_BARRIER, StoreStoreBarrier);
875 mono_mb_emit_ldloc (mb, p_var);
876 mono_mb_emit_ldarg (mb, 0);
877 mono_mb_emit_byte (mb, CEE_STIND_I);
879 if (atype == ATYPE_VECTOR) {
880 /* arr->max_length = max_length; */
881 mono_mb_emit_ldloc (mb, p_var);
882 mono_mb_emit_ldflda (mb, G_STRUCT_OFFSET (MonoArray, max_length));
883 mono_mb_emit_ldarg (mb, 1);
884 #ifdef MONO_BIG_ARRAYS
885 mono_mb_emit_byte (mb, CEE_STIND_I);
887 mono_mb_emit_byte (mb, CEE_STIND_I4);
892 We must make sure both vtable and max_length are globaly visible before returning to managed land.
894 mono_mb_emit_byte ((mb), MONO_CUSTOM_PREFIX);
895 mono_mb_emit_op (mb, CEE_MONO_MEMORY_BARRIER, StoreStoreBarrier);
898 mono_mb_emit_ldloc (mb, p_var);
899 mono_mb_emit_byte (mb, CEE_RET);
901 res = mono_mb_create_method (mb, csig, 8);
903 mono_method_get_header (res)->init_locals = FALSE;
905 info = mono_image_alloc0 (mono_defaults.corlib, sizeof (AllocatorWrapperInfo));
906 info->gc_name = "sgen";
907 info->alloc_type = atype;
908 mono_marshal_set_wrapper_info (res, info);
915 * Generate an allocator method implementing the fast path of mono_gc_alloc_obj ().
916 * The signature of the called method is:
917 * object allocate (MonoVTable *vtable)
920 mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box)
922 #ifdef MANAGED_ALLOCATION
923 MonoClass *klass = vtable->klass;
925 #ifdef HAVE_KW_THREAD
926 int tlab_next_offset = -1;
927 int tlab_temp_end_offset = -1;
928 MONO_THREAD_VAR_OFFSET (tlab_next, tlab_next_offset);
929 MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
931 if (tlab_next_offset == -1 || tlab_temp_end_offset == -1)
935 if (!mono_runtime_has_tls_get ())
937 if (klass->instance_size > tlab_size)
939 if (klass->has_finalize || klass->marshalbyref || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS))
943 if (klass->byval_arg.type == MONO_TYPE_STRING)
945 if (collect_before_allocs)
948 if (ALIGN_TO (klass->instance_size, ALLOC_ALIGN) < MAX_SMALL_OBJ_SIZE)
949 return mono_gc_get_managed_allocator_by_type (ATYPE_SMALL);
951 return mono_gc_get_managed_allocator_by_type (ATYPE_NORMAL);
958 mono_gc_get_managed_array_allocator (MonoVTable *vtable, int rank)
960 #ifdef MANAGED_ALLOCATION
961 MonoClass *klass = vtable->klass;
963 #ifdef HAVE_KW_THREAD
964 int tlab_next_offset = -1;
965 int tlab_temp_end_offset = -1;
966 MONO_THREAD_VAR_OFFSET (tlab_next, tlab_next_offset);
967 MONO_THREAD_VAR_OFFSET (tlab_temp_end, tlab_temp_end_offset);
969 if (tlab_next_offset == -1 || tlab_temp_end_offset == -1)
975 if (!mono_runtime_has_tls_get ())
977 if (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS)
979 if (has_per_allocation_action)
981 g_assert (!mono_class_has_finalizer (klass) && !klass->marshalbyref);
983 return mono_gc_get_managed_allocator_by_type (ATYPE_VECTOR);
990 mono_gc_get_managed_allocator_by_type (int atype)
992 #ifdef MANAGED_ALLOCATION
995 if (!mono_runtime_has_tls_get ())
999 res = alloc_method_cache [atype];
1001 res = alloc_method_cache [atype] = create_allocator (atype);
1002 mono_loader_unlock ();
1010 mono_gc_get_managed_allocator_types (void)
1016 sgen_is_managed_allocator (MonoMethod *method)
1020 for (i = 0; i < ATYPE_NUM; ++i)
1021 if (method == alloc_method_cache [i])
1027 sgen_has_managed_allocator (void)
1031 for (i = 0; i < ATYPE_NUM; ++i)
1032 if (alloc_method_cache [i])
1037 #ifdef HEAVY_STATISTICS
1039 sgen_alloc_init_heavy_stats (void)
1041 mono_counters_register ("# objects allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced);
1042 mono_counters_register ("bytes allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced);
1043 mono_counters_register ("bytes allocated in LOS", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_los);
1047 #endif /*HAVE_SGEN_GC*/