2 * sgen-marksweep.c: The Mark & Sweep major collector.
5 * Mark Probst <mark.probst@gmail.com>
7 * Copyright 2009-2010 Novell, Inc.
8 * Copyright (C) 2012 Xamarin Inc
10 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
22 #include "mono/sgen/sgen-gc.h"
23 #include "mono/sgen/sgen-protocol.h"
24 #include "mono/sgen/sgen-cardtable.h"
25 #include "mono/sgen/sgen-memory-governor.h"
26 #include "mono/sgen/sgen-layout-stats.h"
27 #include "mono/sgen/sgen-pointer-queue.h"
28 #include "mono/sgen/sgen-array-list.h"
29 #include "mono/sgen/sgen-pinning.h"
30 #include "mono/sgen/sgen-workers.h"
31 #include "mono/sgen/sgen-thread-pool.h"
32 #include "mono/sgen/sgen-client.h"
33 #include "mono/utils/mono-memory-model.h"
35 #if defined(ARCH_MIN_MS_BLOCK_SIZE) && defined(ARCH_MIN_MS_BLOCK_SIZE_SHIFT)
36 #define MS_BLOCK_SIZE ARCH_MIN_MS_BLOCK_SIZE
37 #define MS_BLOCK_SIZE_SHIFT ARCH_MIN_MS_BLOCK_SIZE_SHIFT
39 #define MS_BLOCK_SIZE_SHIFT 14 /* INT FASTENABLE */
40 #define MS_BLOCK_SIZE (1 << MS_BLOCK_SIZE_SHIFT)
42 #define MAJOR_SECTION_SIZE MS_BLOCK_SIZE
43 #define CARDS_PER_BLOCK (MS_BLOCK_SIZE / CARD_SIZE_IN_BYTES)
46 * Don't allocate single blocks, but alloc a contingent of this many
47 * blocks in one swoop. This must be a power of two.
49 #define MS_BLOCK_ALLOC_NUM 32
52 * Number of bytes before the first object in a block. At the start
53 * of a block is the MSBlockHeader, then opional padding, then come
54 * the objects, so this must be >= sizeof (MSBlockHeader).
56 #define MS_BLOCK_SKIP ((sizeof (MSBlockHeader) + 15) & ~15)
58 #define MS_BLOCK_FREE (MS_BLOCK_SIZE - MS_BLOCK_SKIP)
60 #define MS_NUM_MARK_WORDS (MS_BLOCK_SIZE / SGEN_ALLOC_ALIGN + sizeof (guint32) * 8 - 1) / (sizeof (guint32) * 8)
63 * Blocks progress from one state to the next:
65 * SWEPT The block is fully swept. It might or might not be in
68 * MARKING The block might or might not contain live objects. If
69 * we're in between an initial collection pause and the
70 * finishing pause, the block might or might not be in a
73 * CHECKING The sweep thread is investigating the block to determine
74 * whether or not it contains live objects. The block is
77 * NEED_SWEEPING The block contains live objects but has not yet been
78 * swept. It also contains free slots. It is in a block
81 * SWEEPING The block is being swept. It might be in a free list.
88 BLOCK_STATE_NEED_SWEEPING,
92 typedef struct _MSBlockInfo MSBlockInfo;
96 * FIXME: Do we even need this? It's only used during sweep and might be worth
97 * recalculating to save the space.
99 guint16 obj_size_index;
100 /* FIXME: Reduce this - it only needs a byte. */
101 volatile gint32 state;
103 unsigned int pinned : 1;
104 unsigned int has_references : 1;
105 unsigned int has_pinned : 1; /* means cannot evacuate */
106 unsigned int is_to_space : 1;
107 void ** volatile free_list;
108 MSBlockInfo * volatile next_free;
109 guint8 * volatile cardtable_mod_union;
110 guint32 mark_words [MS_NUM_MARK_WORDS];
113 #define MS_BLOCK_FOR_BLOCK_INFO(b) ((char*)(b))
115 #define MS_BLOCK_OBJ(b,i) ((GCObject *)(MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (b)->obj_size * (i)))
116 #define MS_BLOCK_OBJ_FOR_SIZE(b,i,obj_size) (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (obj_size) * (i))
117 #define MS_BLOCK_DATA_FOR_OBJ(o) ((char*)((mword)(o) & ~(mword)(MS_BLOCK_SIZE - 1)))
123 #define MS_BLOCK_FOR_OBJ(o) (&((MSBlockHeader*)MS_BLOCK_DATA_FOR_OBJ ((o)))->info)
125 /* object index will always be small */
126 #define MS_BLOCK_OBJ_INDEX(o,b) ((int)(((char*)(o) - (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP)) / (b)->obj_size))
128 //casting to int is fine since blocks are 32k
129 #define MS_CALC_MARK_BIT(w,b,o) do { \
130 int i = ((int)((char*)(o) - MS_BLOCK_DATA_FOR_OBJ ((o)))) >> SGEN_ALLOC_ALIGN_BITS; \
135 #define MS_MARK_BIT(bl,w,b) ((bl)->mark_words [(w)] & (ONE_P << (b)))
136 #define MS_SET_MARK_BIT(bl,w,b) ((bl)->mark_words [(w)] |= (ONE_P << (b)))
137 #define MS_SET_MARK_BIT_PAR(bl,w,b,first) do { \
138 guint32 tmp_mark_word = (bl)->mark_words [(w)]; \
139 guint32 old_mark_word; \
141 while (!(tmp_mark_word & (ONE_P << (b)))) { \
142 old_mark_word = tmp_mark_word; \
143 tmp_mark_word = InterlockedCompareExchange ((volatile gint32*)&(bl)->mark_words [w], old_mark_word | (ONE_P << (b)), old_mark_word); \
144 if (tmp_mark_word == old_mark_word) { \
152 #define MS_OBJ_ALLOCED(o,b) (*(void**)(o) && (*(char**)(o) < MS_BLOCK_FOR_BLOCK_INFO (b) || *(char**)(o) >= MS_BLOCK_FOR_BLOCK_INFO (b) + MS_BLOCK_SIZE))
154 #define MS_BLOCK_OBJ_SIZE_FACTOR (pow (2.0, 1.0 / 3))
157 * This way we can lookup block object size indexes for sizes up to
158 * 256 bytes with a single load.
160 #define MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES 32
162 static int *block_obj_sizes;
163 static int num_block_obj_sizes;
164 static int fast_block_obj_size_indexes [MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES];
166 #define MS_BLOCK_FLAG_PINNED 1
167 #define MS_BLOCK_FLAG_REFS 2
169 #define MS_BLOCK_TYPE_MAX 4
171 static gboolean *evacuate_block_obj_sizes;
172 static float evacuation_threshold = 0.666f;
174 static gboolean lazy_sweep = TRUE;
178 SWEEP_STATE_NEED_SWEEPING,
179 SWEEP_STATE_SWEEPING,
180 SWEEP_STATE_SWEEPING_AND_ITERATING,
181 SWEEP_STATE_COMPACTING
184 static volatile int sweep_state = SWEEP_STATE_SWEPT;
186 static gboolean concurrent_mark;
187 static gboolean concurrent_sweep = TRUE;
189 #define BLOCK_IS_TAGGED_HAS_REFERENCES(bl) SGEN_POINTER_IS_TAGGED_1 ((bl))
190 #define BLOCK_TAG_HAS_REFERENCES(bl) SGEN_POINTER_TAG_1 ((bl))
192 #define BLOCK_IS_TAGGED_CHECKING(bl) SGEN_POINTER_IS_TAGGED_2 ((bl))
193 #define BLOCK_TAG_CHECKING(bl) SGEN_POINTER_TAG_2 ((bl))
195 #define BLOCK_UNTAG(bl) ((MSBlockInfo *)SGEN_POINTER_UNTAG_12 ((bl)))
197 #define BLOCK_TAG(bl) ((bl)->has_references ? BLOCK_TAG_HAS_REFERENCES ((bl)) : (bl))
199 /* all allocated blocks in the system */
200 static SgenArrayList allocated_blocks = SGEN_ARRAY_LIST_INIT (NULL, sgen_array_list_default_is_slot_set, sgen_array_list_default_cas_setter, INTERNAL_MEM_PIN_QUEUE);
202 /* non-allocated block free-list */
203 static void *empty_blocks = NULL;
204 static size_t num_empty_blocks = 0;
207 * We can iterate the block list also while sweep is in progress but we
208 * need to account for blocks that will be checked for sweeping and even
209 * freed in the process.
211 #define FOREACH_BLOCK_NO_LOCK(bl) { \
212 volatile gpointer *slot; \
213 SGEN_ARRAY_LIST_FOREACH_SLOT (&allocated_blocks, slot) { \
214 (bl) = BLOCK_UNTAG (*slot); \
217 #define FOREACH_BLOCK_HAS_REFERENCES_NO_LOCK(bl,hr) { \
218 volatile gpointer *slot; \
219 SGEN_ARRAY_LIST_FOREACH_SLOT (&allocated_blocks, slot) { \
220 (bl) = (MSBlockInfo *) (*slot); \
223 (hr) = BLOCK_IS_TAGGED_HAS_REFERENCES ((bl)); \
224 (bl) = BLOCK_UNTAG ((bl));
225 #define END_FOREACH_BLOCK_NO_LOCK } SGEN_ARRAY_LIST_END_FOREACH_SLOT; }
227 static volatile size_t num_major_sections = 0;
229 * One free block list for each block object size. We add and remove blocks from these
230 * lists lock-free via CAS.
232 * Blocks accessed/removed from `free_block_lists`:
233 * from the mutator (with GC lock held)
234 * in nursery collections
235 * in non-concurrent major collections
236 * in the finishing pause of concurrent major collections (whole list is cleared)
238 * Blocks added to `free_block_lists`:
239 * in the sweeping thread
240 * during nursery collections
241 * from domain clearing (with the world stopped and no sweeping happening)
243 * The only item of those that doesn't require the GC lock is the sweep thread. The sweep
244 * thread only ever adds blocks to the free list, so the ABA problem can't occur.
246 static MSBlockInfo * volatile *free_block_lists [MS_BLOCK_TYPE_MAX];
247 static MonoNativeTlsKey worker_block_free_list_key;
249 static guint64 stat_major_blocks_alloced = 0;
250 static guint64 stat_major_blocks_freed = 0;
251 static guint64 stat_major_blocks_lazy_swept = 0;
253 static guint64 stat_major_blocks_freed_ideal = 0;
254 static guint64 stat_major_blocks_freed_less_ideal = 0;
255 static guint64 stat_major_blocks_freed_individual = 0;
256 static guint64 stat_major_blocks_alloced_less_ideal = 0;
258 #ifdef SGEN_COUNT_NUMBER_OF_MAJOR_OBJECTS_MARKED
259 static guint64 num_major_objects_marked = 0;
260 #define INC_NUM_MAJOR_OBJECTS_MARKED() (++num_major_objects_marked)
262 #define INC_NUM_MAJOR_OBJECTS_MARKED()
265 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
266 static mono_mutex_t scanned_objects_list_lock;
267 static SgenPointerQueue scanned_objects_list;
270 add_scanned_object (void *ptr)
272 if (!binary_protocol_is_enabled ())
275 mono_os_mutex_lock (&scanned_objects_list_lock);
276 sgen_pointer_queue_add (&scanned_objects_list, ptr);
277 mono_os_mutex_unlock (&scanned_objects_list_lock);
281 static gboolean sweep_block (MSBlockInfo *block);
284 ms_find_block_obj_size_index (size_t size)
287 SGEN_ASSERT (9, size <= SGEN_MAX_SMALL_OBJ_SIZE, "size %zd is bigger than max small object size %d", size, SGEN_MAX_SMALL_OBJ_SIZE);
288 for (i = 0; i < num_block_obj_sizes; ++i)
289 if (block_obj_sizes [i] >= size)
291 g_error ("no object of size %zd\n", size);
295 #define FREE_BLOCKS_FROM(lists,p,r) (lists [((p) ? MS_BLOCK_FLAG_PINNED : 0) | ((r) ? MS_BLOCK_FLAG_REFS : 0)])
296 #define FREE_BLOCKS(p,r) (FREE_BLOCKS_FROM (free_block_lists, (p), (r)))
297 #define FREE_BLOCKS_LOCAL(p,r) (FREE_BLOCKS_FROM (((MSBlockInfo***)mono_native_tls_get_value (worker_block_free_list_key)), (p), (r)))
299 #define MS_BLOCK_OBJ_SIZE_INDEX(s) \
300 (((s)+7)>>3 < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES ? \
301 fast_block_obj_size_indexes [((s)+7)>>3] : \
302 ms_find_block_obj_size_index ((s)))
305 major_alloc_heap (mword nursery_size, mword nursery_align, int the_nursery_bits)
309 start = (char *)sgen_alloc_os_memory_aligned (nursery_size, nursery_align, (SgenAllocFlags)(SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE), "nursery", MONO_MEM_ACCOUNT_SGEN_NURSERY);
311 start = (char *)sgen_alloc_os_memory (nursery_size, (SgenAllocFlags)(SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE), "nursery", MONO_MEM_ACCOUNT_SGEN_NURSERY);
317 update_heap_boundaries_for_block (MSBlockInfo *block)
319 sgen_update_heap_boundaries ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), (mword)MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE);
326 ms_get_empty_block (void)
330 void *block, *empty, *next;
335 * We try allocating MS_BLOCK_ALLOC_NUM blocks first. If that's
336 * unsuccessful, we halve the number of blocks and try again, until we're at
337 * 1. If that doesn't work, either, we assert.
339 int alloc_num = MS_BLOCK_ALLOC_NUM;
341 p = (char *)sgen_alloc_os_memory_aligned (MS_BLOCK_SIZE * alloc_num, MS_BLOCK_SIZE,
342 (SgenAllocFlags)(SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE),
343 alloc_num == 1 ? "major heap section" : NULL, MONO_MEM_ACCOUNT_SGEN_MARKSWEEP);
349 for (i = 0; i < alloc_num; ++i) {
352 * We do the free list update one after the
353 * other so that other threads can use the new
354 * blocks as quickly as possible.
357 empty = empty_blocks;
358 *(void**)block = empty;
359 } while (SGEN_CAS_PTR ((gpointer*)&empty_blocks, block, empty) != empty);
363 SGEN_ATOMIC_ADD_P (num_empty_blocks, alloc_num);
365 stat_major_blocks_alloced += alloc_num;
366 #if SIZEOF_VOID_P != 8
367 if (alloc_num != MS_BLOCK_ALLOC_NUM)
368 stat_major_blocks_alloced_less_ideal += alloc_num;
373 empty = empty_blocks;
377 next = *(void**)block;
378 } while (SGEN_CAS_PTR (&empty_blocks, next, empty) != empty);
380 SGEN_ATOMIC_ADD_P (num_empty_blocks, -1);
382 *(void**)block = NULL;
384 g_assert (!((mword)block & (MS_BLOCK_SIZE - 1)));
390 * This doesn't actually free a block immediately, but enqueues it into the `empty_blocks`
391 * list, where it will either be freed later on, or reused in nursery collections.
394 ms_free_block (MSBlockInfo *info)
397 char *block = MS_BLOCK_FOR_BLOCK_INFO (info);
399 sgen_memgov_release_space (MS_BLOCK_SIZE, SPACE_MAJOR);
400 if (info->cardtable_mod_union)
401 sgen_card_table_free_mod_union (info->cardtable_mod_union, block, MS_BLOCK_SIZE);
402 memset (block, 0, MS_BLOCK_SIZE);
405 empty = empty_blocks;
406 *(void**)block = empty;
407 } while (SGEN_CAS_PTR (&empty_blocks, block, empty) != empty);
409 SGEN_ATOMIC_ADD_P (num_empty_blocks, 1);
411 binary_protocol_block_free (block, MS_BLOCK_SIZE);
415 sweep_in_progress (void)
417 int state = sweep_state;
418 return state == SWEEP_STATE_SWEEPING ||
419 state == SWEEP_STATE_SWEEPING_AND_ITERATING ||
420 state == SWEEP_STATE_COMPACTING;
423 static inline gboolean
424 block_is_swept_or_marking (MSBlockInfo *block)
426 gint32 state = block->state;
427 return state == BLOCK_STATE_SWEPT || state == BLOCK_STATE_MARKING;
430 //#define MARKSWEEP_CONSISTENCY_CHECK
432 #ifdef MARKSWEEP_CONSISTENCY_CHECK
434 check_block_free_list (MSBlockInfo *block, int size, gboolean pinned)
436 SGEN_ASSERT (0, !sweep_in_progress (), "Can't examine allocated blocks during sweep");
437 for (; block; block = block->next_free) {
438 SGEN_ASSERT (0, block->state != BLOCK_STATE_CHECKING, "Can't have a block we're checking in a free list.");
439 g_assert (block->obj_size == size);
440 g_assert ((pinned && block->pinned) || (!pinned && !block->pinned));
442 /* blocks in the free lists must have at least
444 g_assert (block->free_list);
446 /* the block must be in the allocated_blocks array */
447 g_assert (sgen_array_list_find (&allocated_blocks, BLOCK_TAG (block)) != (guint32)-1);
452 check_empty_blocks (void)
456 for (p = empty_blocks; p; p = *(void**)p)
458 g_assert (i == num_empty_blocks);
462 consistency_check (void)
467 /* check all blocks */
468 FOREACH_BLOCK_NO_LOCK (block) {
469 int count = MS_BLOCK_FREE / block->obj_size;
473 /* count number of free slots */
474 for (i = 0; i < count; ++i) {
475 void **obj = (void**) MS_BLOCK_OBJ (block, i);
476 if (!MS_OBJ_ALLOCED (obj, block))
480 /* check free list */
481 for (free = block->free_list; free; free = (void**)*free) {
482 g_assert (MS_BLOCK_FOR_OBJ (free) == block);
485 g_assert (num_free == 0);
487 /* check all mark words are zero */
488 if (!sgen_concurrent_collection_in_progress () && block_is_swept_or_marking (block)) {
489 for (i = 0; i < MS_NUM_MARK_WORDS; ++i)
490 g_assert (block->mark_words [i] == 0);
492 } END_FOREACH_BLOCK_NO_LOCK;
494 /* check free blocks */
495 for (i = 0; i < num_block_obj_sizes; ++i) {
497 for (j = 0; j < MS_BLOCK_TYPE_MAX; ++j)
498 check_block_free_list (free_block_lists [j][i], block_obj_sizes [i], j & MS_BLOCK_FLAG_PINNED);
501 check_empty_blocks ();
506 add_free_block (MSBlockInfo * volatile *free_blocks, int size_index, MSBlockInfo *block)
510 block->next_free = old = free_blocks [size_index];
511 } while (SGEN_CAS_PTR ((volatile gpointer *)&free_blocks [size_index], block, old) != old);
514 static void major_finish_sweep_checking (void);
517 ms_alloc_block (int size_index, gboolean pinned, gboolean has_references)
519 int size = block_obj_sizes [size_index];
520 int count = MS_BLOCK_FREE / size;
522 MSBlockInfo * volatile * free_blocks = FREE_BLOCKS (pinned, has_references);
526 if (!sgen_memgov_try_alloc_space (MS_BLOCK_SIZE, SPACE_MAJOR))
529 info = (MSBlockInfo*)ms_get_empty_block ();
531 SGEN_ASSERT (9, count >= 2, "block with %d objects, it must hold at least 2", count);
533 info->obj_size = size;
534 info->obj_size_index = size_index;
535 info->pinned = pinned;
536 info->has_references = has_references;
537 info->has_pinned = pinned;
539 * Blocks that are to-space are not evacuated from. During an major collection
540 * blocks are allocated for two reasons: evacuating objects from the nursery and
541 * evacuating them from major blocks marked for evacuation. In both cases we don't
542 * want further evacuation. We also don't want to evacuate objects allocated during
543 * the concurrent mark since it would add pointless stress on the finishing pause.
545 info->is_to_space = (sgen_get_current_collection_generation () == GENERATION_OLD) || sgen_concurrent_collection_in_progress ();
546 info->state = info->is_to_space ? BLOCK_STATE_MARKING : BLOCK_STATE_SWEPT;
547 SGEN_ASSERT (6, !sweep_in_progress () || info->state == BLOCK_STATE_SWEPT, "How do we add a new block to be swept while sweeping?");
548 info->cardtable_mod_union = NULL;
550 update_heap_boundaries_for_block (info);
552 binary_protocol_block_alloc (info, MS_BLOCK_SIZE);
554 /* build free list */
555 obj_start = MS_BLOCK_FOR_BLOCK_INFO (info) + MS_BLOCK_SKIP;
556 info->free_list = (void**)obj_start;
557 /* we're skipping the last one - it must be nulled */
558 for (i = 0; i < count - 1; ++i) {
559 char *next_obj_start = obj_start + size;
560 *(void**)obj_start = next_obj_start;
561 obj_start = next_obj_start;
564 *(void**)obj_start = NULL;
566 add_free_block (free_blocks, size_index, info);
568 sgen_array_list_add (&allocated_blocks, BLOCK_TAG (info), 0, FALSE);
570 SGEN_ATOMIC_ADD_P (num_major_sections, 1);
575 ptr_is_in_major_block (char *ptr, char **start, gboolean *pinned)
579 FOREACH_BLOCK_NO_LOCK (block) {
580 if (ptr >= MS_BLOCK_FOR_BLOCK_INFO (block) && ptr <= MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) {
581 int count = MS_BLOCK_FREE / block->obj_size;
586 for (i = 0; i <= count; ++i) {
587 if (ptr >= (char*)MS_BLOCK_OBJ (block, i) && ptr < (char*)MS_BLOCK_OBJ (block, i + 1)) {
589 *start = (char *)MS_BLOCK_OBJ (block, i);
594 *pinned = block->pinned;
597 } END_FOREACH_BLOCK_NO_LOCK;
602 ptr_is_from_pinned_alloc (char *ptr)
605 if (ptr_is_in_major_block (ptr, NULL, &pinned))
611 ensure_can_access_block_free_list (MSBlockInfo *block)
615 switch (block->state) {
616 case BLOCK_STATE_SWEPT:
617 case BLOCK_STATE_MARKING:
619 case BLOCK_STATE_CHECKING:
620 SGEN_ASSERT (0, FALSE, "How did we get a block that's being checked from a free list?");
622 case BLOCK_STATE_NEED_SWEEPING:
623 if (sweep_block (block))
624 ++stat_major_blocks_lazy_swept;
626 case BLOCK_STATE_SWEEPING:
627 /* FIXME: do this more elegantly */
631 SGEN_ASSERT (0, FALSE, "Illegal block state");
638 unlink_slot_from_free_list_uncontested (MSBlockInfo * volatile *free_blocks, int size_index)
640 MSBlockInfo *block, *next_free_block;
641 void *obj, *next_free_slot;
644 block = free_blocks [size_index];
645 SGEN_ASSERT (9, block, "no free block to unlink from free_blocks %p size_index %d", free_blocks, size_index);
647 ensure_can_access_block_free_list (block);
649 obj = block->free_list;
650 SGEN_ASSERT (6, obj, "block %p in free list had no available object to alloc from", block);
652 next_free_slot = *(void**)obj;
653 if (next_free_slot) {
654 block->free_list = (gpointer *)next_free_slot;
658 next_free_block = block->next_free;
659 if (SGEN_CAS_PTR ((volatile gpointer *)&free_blocks [size_index], next_free_block, block) != block)
662 block->free_list = NULL;
663 block->next_free = NULL;
669 alloc_obj (GCVTable vtable, size_t size, gboolean pinned, gboolean has_references)
671 int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
672 MSBlockInfo * volatile * free_blocks = FREE_BLOCKS (pinned, has_references);
675 if (!free_blocks [size_index]) {
676 if (G_UNLIKELY (!ms_alloc_block (size_index, pinned, has_references)))
680 obj = unlink_slot_from_free_list_uncontested (free_blocks, size_index);
682 /* FIXME: assumes object layout */
683 *(GCVTable*)obj = vtable;
685 total_allocated_major += block_obj_sizes [size_index];
687 return (GCObject *)obj;
691 major_alloc_object (GCVTable vtable, size_t size, gboolean has_references)
693 return alloc_obj (vtable, size, FALSE, has_references);
697 * This can only be called by sgen workers. While this is called we assume
698 * that no other thread is accessing the block free lists. The world should
699 * be stopped and the gc thread should be waiting for workers to finish.
702 major_alloc_object_par (GCVTable vtable, size_t size, gboolean has_references)
704 int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
705 MSBlockInfo * volatile * free_blocks = FREE_BLOCKS (FALSE, has_references);
706 MSBlockInfo **free_blocks_local = FREE_BLOCKS_LOCAL (FALSE, has_references);
709 if (free_blocks_local [size_index]) {
711 obj = unlink_slot_from_free_list_uncontested (free_blocks_local, size_index);
715 block = free_blocks [size_index];
717 if (G_UNLIKELY (!ms_alloc_block (size_index, FALSE, has_references)))
721 MSBlockInfo *next_free = block->next_free;
723 * Once a block is removed from the main list, it cannot return on the list until
724 * all the workers are finished and sweep is starting. This means we don't need
725 * to account for ABA problems.
727 if (SGEN_CAS_PTR ((volatile gpointer *)&free_blocks [size_index], next_free, block) != block)
729 g_assert (block->free_list);
730 block->next_free = free_blocks_local [size_index];
731 free_blocks_local [size_index] = block;
737 /* FIXME: assumes object layout */
738 *(GCVTable*)obj = vtable;
740 /* FIXME is it worth CAS-ing here */
741 total_allocated_major += block_obj_sizes [size_index];
743 return (GCObject *)obj;
747 * We're not freeing the block if it's empty. We leave that work for
748 * the next major collection.
750 * This is just called from the domain clearing code, which runs in a
751 * single thread and has the GC lock, so we don't need an extra lock.
754 free_object (GCObject *obj, size_t size, gboolean pinned)
756 MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
758 gboolean in_free_list;
760 SGEN_ASSERT (9, sweep_state == SWEEP_STATE_SWEPT, "Should have waited for sweep to free objects.");
762 ensure_can_access_block_free_list (block);
763 SGEN_ASSERT (9, (pinned && block->pinned) || (!pinned && !block->pinned), "free-object pinning mixup object %p pinned %d block %p pinned %d", obj, pinned, block, block->pinned);
764 SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p is already free", obj);
765 MS_CALC_MARK_BIT (word, bit, obj);
766 SGEN_ASSERT (9, !MS_MARK_BIT (block, word, bit), "object %p has mark bit set", obj);
768 memset (obj, 0, size);
770 in_free_list = !!block->free_list;
771 *(void**)obj = block->free_list;
772 block->free_list = (void**)obj;
775 MSBlockInfo * volatile *free_blocks = FREE_BLOCKS (pinned, block->has_references);
776 int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
777 SGEN_ASSERT (9, !block->next_free, "block %p doesn't have a free-list of object but belongs to a free-list of blocks", block);
778 add_free_block (free_blocks, size_index, block);
783 major_free_non_pinned_object (GCObject *obj, size_t size)
785 free_object (obj, size, FALSE);
788 /* size is a multiple of SGEN_ALLOC_ALIGN */
790 major_alloc_small_pinned_obj (GCVTable vtable, size_t size, gboolean has_references)
794 res = alloc_obj (vtable, size, TRUE, has_references);
795 /*If we failed to alloc memory, we better try releasing memory
796 *as pinned alloc is requested by the runtime.
799 sgen_perform_collection (0, GENERATION_OLD, "pinned alloc failure", TRUE, TRUE);
800 res = alloc_obj (vtable, size, TRUE, has_references);
802 return (GCObject *)res;
806 free_pinned_object (GCObject *obj, size_t size)
808 free_object (obj, size, TRUE);
812 * size is already rounded up and we hold the GC lock.
815 major_alloc_degraded (GCVTable vtable, size_t size)
819 obj = alloc_obj (vtable, size, FALSE, SGEN_VTABLE_HAS_REFERENCES (vtable));
820 if (G_LIKELY (obj)) {
821 HEAVY_STAT (++stat_objects_alloced_degraded);
822 HEAVY_STAT (stat_bytes_alloced_degraded += size);
828 * obj is some object. If it's not in the major heap (i.e. if it's in
829 * the nursery or LOS), return FALSE. Otherwise return whether it's
830 * been marked or copied.
833 major_is_object_live (GCObject *obj)
839 if (sgen_ptr_in_nursery (obj))
842 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size (obj));
845 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
848 /* now we know it's in a major block */
849 block = MS_BLOCK_FOR_OBJ (obj);
850 SGEN_ASSERT (9, !block->pinned, "block %p is pinned, BTW why is this bad?", block);
851 MS_CALC_MARK_BIT (word, bit, obj);
852 return MS_MARK_BIT (block, word, bit) ? TRUE : FALSE;
856 major_ptr_is_in_non_pinned_space (char *ptr, char **start)
859 if (ptr_is_in_major_block (ptr, start, &pinned))
865 try_set_sweep_state (int new_, int expected)
867 int old = SGEN_CAS (&sweep_state, new_, expected);
868 return old == expected;
872 set_sweep_state (int new_, int expected)
874 gboolean success = try_set_sweep_state (new_, expected);
875 SGEN_ASSERT (0, success, "Could not set sweep state.");
878 static gboolean ensure_block_is_checked_for_sweeping (guint32 block_index, gboolean wait, gboolean *have_checked);
880 static SgenThreadPoolJob * volatile sweep_job;
881 static SgenThreadPoolJob * volatile sweep_blocks_job;
884 major_finish_sweep_checking (void)
887 SgenThreadPoolJob *job;
890 switch (sweep_state) {
891 case SWEEP_STATE_SWEPT:
892 case SWEEP_STATE_NEED_SWEEPING:
894 case SWEEP_STATE_SWEEPING:
895 if (try_set_sweep_state (SWEEP_STATE_SWEEPING_AND_ITERATING, SWEEP_STATE_SWEEPING))
898 case SWEEP_STATE_SWEEPING_AND_ITERATING:
899 SGEN_ASSERT (0, FALSE, "Is there another minor collection running?");
901 case SWEEP_STATE_COMPACTING:
904 SGEN_ASSERT (0, FALSE, "Invalid sweep state.");
909 * We're running with the world stopped and the only other thread doing work is the
910 * sweep thread, which doesn't add blocks to the array, so we can safely access
913 for (block_index = 0; block_index < allocated_blocks.next_slot; ++block_index)
914 ensure_block_is_checked_for_sweeping (block_index, FALSE, NULL);
916 set_sweep_state (SWEEP_STATE_SWEEPING, SWEEP_STATE_SWEEPING_AND_ITERATING);
921 sgen_thread_pool_job_wait (job);
922 SGEN_ASSERT (0, !sweep_job, "Why did the sweep job not null itself?");
923 SGEN_ASSERT (0, sweep_state == SWEEP_STATE_SWEPT, "How is the sweep job done but we're not swept?");
927 major_iterate_objects (IterateObjectsFlags flags, IterateObjectCallbackFunc callback, void *data)
929 gboolean sweep = flags & ITERATE_OBJECTS_SWEEP;
930 gboolean non_pinned = flags & ITERATE_OBJECTS_NON_PINNED;
931 gboolean pinned = flags & ITERATE_OBJECTS_PINNED;
934 /* No actual sweeping will take place if we are in the middle of a major collection. */
935 major_finish_sweep_checking ();
936 FOREACH_BLOCK_NO_LOCK (block) {
937 int count = MS_BLOCK_FREE / block->obj_size;
940 if (block->pinned && !pinned)
942 if (!block->pinned && !non_pinned)
944 if (sweep && lazy_sweep && !block_is_swept_or_marking (block)) {
946 SGEN_ASSERT (6, block->state == BLOCK_STATE_SWEPT, "Block must be swept after sweeping");
949 for (i = 0; i < count; ++i) {
950 void **obj = (void**) MS_BLOCK_OBJ (block, i);
951 if (MS_OBJ_ALLOCED (obj, block))
952 callback ((GCObject*)obj, block->obj_size, data);
954 } END_FOREACH_BLOCK_NO_LOCK;
958 major_is_valid_object (char *object)
962 FOREACH_BLOCK_NO_LOCK (block) {
966 if ((MS_BLOCK_FOR_BLOCK_INFO (block) > object) || ((MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) <= object))
969 idx = MS_BLOCK_OBJ_INDEX (object, block);
970 obj = (char*)MS_BLOCK_OBJ (block, idx);
973 return MS_OBJ_ALLOCED (obj, block);
974 } END_FOREACH_BLOCK_NO_LOCK;
981 major_describe_pointer (char *ptr)
985 FOREACH_BLOCK_NO_LOCK (block) {
993 if ((MS_BLOCK_FOR_BLOCK_INFO (block) > ptr) || ((MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) <= ptr))
996 SGEN_LOG (0, "major-ptr (block %p sz %d pin %d ref %d)\n",
997 MS_BLOCK_FOR_BLOCK_INFO (block), block->obj_size, block->pinned, block->has_references);
999 idx = MS_BLOCK_OBJ_INDEX (ptr, block);
1000 obj = (char*)MS_BLOCK_OBJ (block, idx);
1001 live = MS_OBJ_ALLOCED (obj, block);
1002 vtable = live ? SGEN_LOAD_VTABLE ((GCObject*)obj) : NULL;
1004 MS_CALC_MARK_BIT (w, b, obj);
1005 marked = MS_MARK_BIT (block, w, b);
1008 SGEN_LOG (0, "\t(");
1010 SGEN_LOG (0, "object");
1012 SGEN_LOG (0, "dead-object");
1015 SGEN_LOG (0, "interior-ptr offset %zd", ptr - obj);
1017 SGEN_LOG (0, "dead-interior-ptr offset %zd", ptr - obj);
1020 SGEN_LOG (0, " marked %d)\n", marked ? 1 : 0);
1023 } END_FOREACH_BLOCK_NO_LOCK;
1029 major_check_scan_starts (void)
1034 major_dump_heap (FILE *heap_dump_file)
1037 int *slots_available = (int *)alloca (sizeof (int) * num_block_obj_sizes);
1038 int *slots_used = (int *)alloca (sizeof (int) * num_block_obj_sizes);
1041 for (i = 0; i < num_block_obj_sizes; ++i)
1042 slots_available [i] = slots_used [i] = 0;
1044 FOREACH_BLOCK_NO_LOCK (block) {
1045 int index = ms_find_block_obj_size_index (block->obj_size);
1046 int count = MS_BLOCK_FREE / block->obj_size;
1048 slots_available [index] += count;
1049 for (i = 0; i < count; ++i) {
1050 if (MS_OBJ_ALLOCED (MS_BLOCK_OBJ (block, i), block))
1051 ++slots_used [index];
1053 } END_FOREACH_BLOCK_NO_LOCK;
1055 fprintf (heap_dump_file, "<occupancies>\n");
1056 for (i = 0; i < num_block_obj_sizes; ++i) {
1057 fprintf (heap_dump_file, "<occupancy size=\"%d\" available=\"%d\" used=\"%d\" />\n",
1058 block_obj_sizes [i], slots_available [i], slots_used [i]);
1060 fprintf (heap_dump_file, "</occupancies>\n");
1062 FOREACH_BLOCK_NO_LOCK (block) {
1063 int count = MS_BLOCK_FREE / block->obj_size;
1067 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%zu\">\n", "old", (size_t)MS_BLOCK_FREE);
1069 for (i = 0; i <= count; ++i) {
1070 if ((i < count) && MS_OBJ_ALLOCED (MS_BLOCK_OBJ (block, i), block)) {
1075 sgen_dump_occupied ((char *)MS_BLOCK_OBJ (block, start), (char *)MS_BLOCK_OBJ (block, i), MS_BLOCK_FOR_BLOCK_INFO (block));
1081 fprintf (heap_dump_file, "</section>\n");
1082 } END_FOREACH_BLOCK_NO_LOCK;
1086 get_cardtable_mod_union_for_block (MSBlockInfo *block, gboolean allocate)
1088 guint8 *mod_union = block->cardtable_mod_union;
1094 mod_union = sgen_card_table_alloc_mod_union (MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE);
1095 other = (guint8 *)SGEN_CAS_PTR ((gpointer*)&block->cardtable_mod_union, mod_union, NULL);
1097 SGEN_ASSERT (0, block->cardtable_mod_union == mod_union, "Why did CAS not replace?");
1100 sgen_card_table_free_mod_union (mod_union, MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE);
1104 static inline guint8*
1105 major_get_cardtable_mod_union_for_reference (char *ptr)
1107 MSBlockInfo *block = MS_BLOCK_FOR_OBJ (ptr);
1108 size_t offset = sgen_card_table_get_card_offset (ptr, (char*)sgen_card_table_align_pointer (MS_BLOCK_FOR_BLOCK_INFO (block)));
1109 guint8 *mod_union = get_cardtable_mod_union_for_block (block, TRUE);
1110 SGEN_ASSERT (0, mod_union, "FIXME: optionally allocate the mod union if it's not here and CAS it in.");
1111 return &mod_union [offset];
1115 * Mark the mod-union card for `ptr`, which must be a reference within the object `obj`.
1118 mark_mod_union_card (GCObject *obj, void **ptr, GCObject *value_obj)
1120 int type = sgen_obj_get_descriptor (obj) & DESC_TYPE_MASK;
1121 if (sgen_safe_object_is_small (obj, type)) {
1122 guint8 *card_byte = major_get_cardtable_mod_union_for_reference ((char*)ptr);
1123 SGEN_ASSERT (0, MS_BLOCK_FOR_OBJ (obj) == MS_BLOCK_FOR_OBJ (ptr), "How can an object and a reference inside it not be in the same block?");
1126 sgen_los_mark_mod_union_card (obj, ptr);
1128 binary_protocol_mod_union_remset (obj, ptr, value_obj, SGEN_LOAD_VTABLE (value_obj));
1131 static inline gboolean
1132 major_block_is_evacuating (MSBlockInfo *block)
1134 if (evacuate_block_obj_sizes [block->obj_size_index] &&
1135 !block->has_pinned &&
1136 !block->is_to_space)
1141 #define MS_MARK_OBJECT_AND_ENQUEUE(obj,desc,block,queue) do { \
1142 int __word, __bit; \
1143 MS_CALC_MARK_BIT (__word, __bit, (obj)); \
1144 SGEN_ASSERT (9, MS_OBJ_ALLOCED ((obj), (block)), "object %p not allocated", obj); \
1145 if (!MS_MARK_BIT ((block), __word, __bit)) { \
1146 MS_SET_MARK_BIT ((block), __word, __bit); \
1147 if (sgen_gc_descr_has_references (desc)) \
1148 GRAY_OBJECT_ENQUEUE_SERIAL ((queue), (obj), (desc)); \
1149 binary_protocol_mark ((obj), (gpointer)SGEN_LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((obj))); \
1150 INC_NUM_MAJOR_OBJECTS_MARKED (); \
1153 #define MS_MARK_OBJECT_AND_ENQUEUE_PAR(obj,desc,block,queue) do { \
1154 int __word, __bit; \
1156 MS_CALC_MARK_BIT (__word, __bit, (obj)); \
1157 SGEN_ASSERT (9, MS_OBJ_ALLOCED ((obj), (block)), "object %p not allocated", obj); \
1158 MS_SET_MARK_BIT_PAR ((block), __word, __bit, first); \
1160 if (sgen_gc_descr_has_references (desc)) \
1161 GRAY_OBJECT_ENQUEUE_PARALLEL ((queue), (obj), (desc)); \
1162 binary_protocol_mark ((obj), (gpointer)SGEN_LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((obj))); \
1163 INC_NUM_MAJOR_OBJECTS_MARKED (); \
1170 pin_major_object (GCObject *obj, SgenGrayQueue *queue)
1174 if (concurrent_mark)
1175 g_assert_not_reached ();
1177 block = MS_BLOCK_FOR_OBJ (obj);
1178 block->has_pinned = TRUE;
1179 MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
1182 #define COPY_OR_MARK_PARALLEL
1183 #include "sgen-major-copy-object.h"
1186 major_get_and_reset_num_major_objects_marked (void)
1188 #ifdef SGEN_COUNT_NUMBER_OF_MAJOR_OBJECTS_MARKED
1189 long long num = num_major_objects_marked;
1190 num_major_objects_marked = 0;
1197 #define PREFETCH_CARDS 1 /* BOOL FASTENABLE */
1199 #undef PREFETCH_CARDS
1202 /* gcc 4.2.1 from xcode4 crashes on sgen_card_table_get_card_address () when this is enabled */
1203 #if defined(PLATFORM_MACOSX)
1204 #if MONO_GNUC_VERSION <= 40300
1205 #undef PREFETCH_CARDS
1209 #ifdef HEAVY_STATISTICS
1210 static guint64 stat_optimized_copy;
1211 static guint64 stat_optimized_copy_nursery;
1212 static guint64 stat_optimized_copy_nursery_forwarded;
1213 static guint64 stat_optimized_copy_nursery_pinned;
1214 static guint64 stat_optimized_copy_major;
1215 static guint64 stat_optimized_copy_major_small_fast;
1216 static guint64 stat_optimized_copy_major_small_slow;
1217 static guint64 stat_optimized_copy_major_large;
1218 static guint64 stat_optimized_copy_major_forwarded;
1219 static guint64 stat_optimized_copy_major_small_evacuate;
1220 static guint64 stat_optimized_major_scan;
1221 static guint64 stat_optimized_major_scan_no_refs;
1223 static guint64 stat_drain_prefetch_fills;
1224 static guint64 stat_drain_prefetch_fill_failures;
1225 static guint64 stat_drain_loops;
1228 #define COPY_OR_MARK_FUNCTION_NAME major_copy_or_mark_object_no_evacuation
1229 #define SCAN_OBJECT_FUNCTION_NAME major_scan_object_no_evacuation
1230 #define DRAIN_GRAY_STACK_FUNCTION_NAME drain_gray_stack_no_evacuation
1231 #include "sgen-marksweep-drain-gray-stack.h"
1233 #define COPY_OR_MARK_PARALLEL
1234 #define COPY_OR_MARK_FUNCTION_NAME major_copy_or_mark_object_par_no_evacuation
1235 #define SCAN_OBJECT_FUNCTION_NAME major_scan_object_par_no_evacuation
1236 #define DRAIN_GRAY_STACK_FUNCTION_NAME drain_gray_stack_par_no_evacuation
1237 #include "sgen-marksweep-drain-gray-stack.h"
1239 #define COPY_OR_MARK_WITH_EVACUATION
1240 #define COPY_OR_MARK_FUNCTION_NAME major_copy_or_mark_object_with_evacuation
1241 #define SCAN_OBJECT_FUNCTION_NAME major_scan_object_with_evacuation
1242 #define SCAN_VTYPE_FUNCTION_NAME major_scan_vtype_with_evacuation
1243 #define DRAIN_GRAY_STACK_FUNCTION_NAME drain_gray_stack_with_evacuation
1244 #define SCAN_PTR_FIELD_FUNCTION_NAME major_scan_ptr_field_with_evacuation
1245 #include "sgen-marksweep-drain-gray-stack.h"
1247 #define COPY_OR_MARK_PARALLEL
1248 #define COPY_OR_MARK_WITH_EVACUATION
1249 #define COPY_OR_MARK_FUNCTION_NAME major_copy_or_mark_object_par_with_evacuation
1250 #define SCAN_OBJECT_FUNCTION_NAME major_scan_object_par_with_evacuation
1251 #define SCAN_VTYPE_FUNCTION_NAME major_scan_vtype_par_with_evacuation
1252 #define DRAIN_GRAY_STACK_FUNCTION_NAME drain_gray_stack_par_with_evacuation
1253 #define SCAN_PTR_FIELD_FUNCTION_NAME major_scan_ptr_field_par_with_evacuation
1254 #include "sgen-marksweep-drain-gray-stack.h"
1256 #define COPY_OR_MARK_CONCURRENT
1257 #define COPY_OR_MARK_FUNCTION_NAME major_copy_or_mark_object_concurrent_no_evacuation
1258 #define SCAN_OBJECT_FUNCTION_NAME major_scan_object_concurrent_no_evacuation
1259 #define DRAIN_GRAY_STACK_FUNCTION_NAME drain_gray_stack_concurrent_no_evacuation
1260 #include "sgen-marksweep-drain-gray-stack.h"
1262 #define COPY_OR_MARK_PARALLEL
1263 #define COPY_OR_MARK_CONCURRENT
1264 #define COPY_OR_MARK_FUNCTION_NAME major_copy_or_mark_object_concurrent_par_no_evacuation
1265 #define SCAN_OBJECT_FUNCTION_NAME major_scan_object_concurrent_par_no_evacuation
1266 #define DRAIN_GRAY_STACK_FUNCTION_NAME drain_gray_stack_concurrent_par_no_evacuation
1267 #include "sgen-marksweep-drain-gray-stack.h"
1269 #define COPY_OR_MARK_CONCURRENT_WITH_EVACUATION
1270 #define COPY_OR_MARK_FUNCTION_NAME major_copy_or_mark_object_concurrent_with_evacuation
1271 #define SCAN_OBJECT_FUNCTION_NAME major_scan_object_concurrent_with_evacuation
1272 #define SCAN_VTYPE_FUNCTION_NAME major_scan_vtype_concurrent_with_evacuation
1273 #define SCAN_PTR_FIELD_FUNCTION_NAME major_scan_ptr_field_concurrent_with_evacuation
1274 #define DRAIN_GRAY_STACK_FUNCTION_NAME drain_gray_stack_concurrent_with_evacuation
1275 #include "sgen-marksweep-drain-gray-stack.h"
1277 #define COPY_OR_MARK_PARALLEL
1278 #define COPY_OR_MARK_CONCURRENT_WITH_EVACUATION
1279 #define COPY_OR_MARK_FUNCTION_NAME major_copy_or_mark_object_concurrent_par_with_evacuation
1280 #define SCAN_OBJECT_FUNCTION_NAME major_scan_object_concurrent_par_with_evacuation
1281 #define SCAN_VTYPE_FUNCTION_NAME major_scan_vtype_concurrent_par_with_evacuation
1282 #define SCAN_PTR_FIELD_FUNCTION_NAME major_scan_ptr_field_concurrent_par_with_evacuation
1283 #define DRAIN_GRAY_STACK_FUNCTION_NAME drain_gray_stack_concurrent_par_with_evacuation
1284 #include "sgen-marksweep-drain-gray-stack.h"
1286 static inline gboolean
1287 major_is_evacuating (void)
1290 for (i = 0; i < num_block_obj_sizes; ++i) {
1291 if (evacuate_block_obj_sizes [i]) {
1300 drain_gray_stack (SgenGrayQueue *queue)
1302 if (major_is_evacuating ())
1303 return drain_gray_stack_with_evacuation (queue);
1305 return drain_gray_stack_no_evacuation (queue);
1309 drain_gray_stack_par (SgenGrayQueue *queue)
1311 if (major_is_evacuating ())
1312 return drain_gray_stack_par_with_evacuation (queue);
1314 return drain_gray_stack_par_no_evacuation (queue);
1318 drain_gray_stack_concurrent (SgenGrayQueue *queue)
1320 if (major_is_evacuating ())
1321 return drain_gray_stack_concurrent_with_evacuation (queue);
1323 return drain_gray_stack_concurrent_no_evacuation (queue);
1327 drain_gray_stack_concurrent_par (SgenGrayQueue *queue)
1329 if (major_is_evacuating ())
1330 return drain_gray_stack_concurrent_par_with_evacuation (queue);
1332 return drain_gray_stack_concurrent_par_no_evacuation (queue);
1336 major_copy_or_mark_object_canonical (GCObject **ptr, SgenGrayQueue *queue)
1338 major_copy_or_mark_object_with_evacuation (ptr, *ptr, queue);
1342 major_copy_or_mark_object_concurrent_canonical (GCObject **ptr, SgenGrayQueue *queue)
1344 major_copy_or_mark_object_concurrent_with_evacuation (ptr, *ptr, queue);
1348 major_copy_or_mark_object_concurrent_par_canonical (GCObject **ptr, SgenGrayQueue *queue)
1350 major_copy_or_mark_object_concurrent_par_with_evacuation (ptr, *ptr, queue);
1354 major_copy_or_mark_object_concurrent_finish_canonical (GCObject **ptr, SgenGrayQueue *queue)
1356 major_copy_or_mark_object_with_evacuation (ptr, *ptr, queue);
1360 major_copy_or_mark_object_concurrent_par_finish_canonical (GCObject **ptr, SgenGrayQueue *queue)
1362 major_copy_or_mark_object_par_with_evacuation (ptr, *ptr, queue);
1366 mark_pinned_objects_in_block (MSBlockInfo *block, size_t first_entry, size_t last_entry, SgenGrayQueue *queue)
1368 void **entry, **end;
1369 int last_index = -1;
1371 if (first_entry == last_entry)
1374 entry = sgen_pinning_get_entry (first_entry);
1375 end = sgen_pinning_get_entry (last_entry);
1377 for (; entry < end; ++entry) {
1378 int index = MS_BLOCK_OBJ_INDEX (*entry, block);
1380 SGEN_ASSERT (9, index >= 0 && index < MS_BLOCK_FREE / block->obj_size, "invalid object %p index %d max-index %d", *entry, index, (int)(MS_BLOCK_FREE / block->obj_size));
1381 if (index == last_index)
1383 obj = MS_BLOCK_OBJ (block, index);
1384 if (!MS_OBJ_ALLOCED (obj, block))
1386 MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
1387 sgen_pin_stats_register_object (obj, GENERATION_OLD);
1392 * There might have been potential pinning "pointers" into this block, but none of
1393 * them pointed to occupied slots, in which case we don't have to pin the block.
1395 if (last_index >= 0)
1396 block->has_pinned = TRUE;
1400 sweep_block_for_size (MSBlockInfo *block, int count, int obj_size)
1404 for (obj_index = 0; obj_index < count; ++obj_index) {
1406 void *obj = MS_BLOCK_OBJ_FOR_SIZE (block, obj_index, obj_size);
1408 MS_CALC_MARK_BIT (word, bit, obj);
1409 if (MS_MARK_BIT (block, word, bit)) {
1410 SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p not allocated", obj);
1412 /* an unmarked object */
1413 if (MS_OBJ_ALLOCED (obj, block)) {
1415 * FIXME: Merge consecutive
1416 * slots for lower reporting
1417 * overhead. Maybe memset
1418 * will also benefit?
1420 binary_protocol_empty (obj, obj_size);
1421 memset (obj, 0, obj_size);
1423 *(void**)obj = block->free_list;
1424 block->free_list = (void **)obj;
1429 static inline gboolean
1430 try_set_block_state (MSBlockInfo *block, gint32 new_state, gint32 expected_state)
1432 gint32 old_state = SGEN_CAS (&block->state, new_state, expected_state);
1433 gboolean success = old_state == expected_state;
1435 binary_protocol_block_set_state (block, MS_BLOCK_SIZE, old_state, new_state);
1440 set_block_state (MSBlockInfo *block, gint32 new_state, gint32 expected_state)
1442 SGEN_ASSERT (6, block->state == expected_state, "Block state incorrect before set");
1443 block->state = new_state;
1444 binary_protocol_block_set_state (block, MS_BLOCK_SIZE, expected_state, new_state);
1448 * If `block` needs sweeping, sweep it and return TRUE. Otherwise return FALSE.
1450 * Sweeping means iterating through the block's slots and building the free-list from the
1451 * unmarked ones. They will also be zeroed. The mark bits will be reset.
1454 sweep_block (MSBlockInfo *block)
1457 void *reversed = NULL;
1460 switch (block->state) {
1461 case BLOCK_STATE_SWEPT:
1463 case BLOCK_STATE_MARKING:
1464 case BLOCK_STATE_CHECKING:
1465 SGEN_ASSERT (0, FALSE, "How did we get to sweep a block that's being marked or being checked?");
1467 case BLOCK_STATE_SWEEPING:
1468 /* FIXME: Do this more elegantly */
1471 case BLOCK_STATE_NEED_SWEEPING:
1472 if (!try_set_block_state (block, BLOCK_STATE_SWEEPING, BLOCK_STATE_NEED_SWEEPING))
1476 SGEN_ASSERT (0, FALSE, "Illegal block state");
1479 SGEN_ASSERT (6, block->state == BLOCK_STATE_SWEEPING, "How did we get here without setting state to sweeping?");
1481 count = MS_BLOCK_FREE / block->obj_size;
1483 block->free_list = NULL;
1485 /* Use inline instances specialized to constant sizes, this allows the compiler to replace the memset calls with inline code */
1486 // FIXME: Add more sizes
1487 switch (block->obj_size) {
1489 sweep_block_for_size (block, count, 16);
1492 sweep_block_for_size (block, count, block->obj_size);
1496 /* reset mark bits */
1497 memset (block->mark_words, 0, sizeof (guint32) * MS_NUM_MARK_WORDS);
1499 /* Reverse free list so that it's in address order */
1501 while (block->free_list) {
1502 void *next = *(void**)block->free_list;
1503 *(void**)block->free_list = reversed;
1504 reversed = block->free_list;
1505 block->free_list = (void **)next;
1507 block->free_list = (void **)reversed;
1509 mono_memory_write_barrier ();
1511 set_block_state (block, BLOCK_STATE_SWEPT, BLOCK_STATE_SWEEPING);
1522 if (sizeof (mword) == 8)
1523 count += __builtin_popcountll (d);
1525 count += __builtin_popcount (d);
1535 /* statistics for evacuation */
1536 static size_t *sweep_slots_available;
1537 static size_t *sweep_slots_used;
1538 static size_t *sweep_num_blocks;
1540 static volatile size_t num_major_sections_before_sweep;
1541 static volatile size_t num_major_sections_freed_in_sweep;
1544 sgen_worker_clear_free_block_lists (WorkerData *worker)
1548 if (!worker->free_block_lists)
1551 for (i = 0; i < MS_BLOCK_TYPE_MAX; i++) {
1552 for (j = 0; j < num_block_obj_sizes; j++) {
1553 ((MSBlockInfo***) worker->free_block_lists) [i][j] = NULL;
1563 for (i = 0; i < num_block_obj_sizes; ++i)
1564 sweep_slots_available [i] = sweep_slots_used [i] = sweep_num_blocks [i] = 0;
1566 /* clear all the free lists */
1567 for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i) {
1568 MSBlockInfo * volatile *free_blocks = free_block_lists [i];
1570 for (j = 0; j < num_block_obj_sizes; ++j)
1571 free_blocks [j] = NULL;
1574 sgen_workers_foreach (sgen_worker_clear_free_block_lists);
1577 static void sweep_finish (void);
1580 * If `wait` is TRUE and the block is currently being checked, this function will wait until
1581 * the checking has finished.
1583 * Returns whether the block is still there. If `wait` is FALSE, the return value will not
1584 * be correct, i.e. must not be used.
1587 ensure_block_is_checked_for_sweeping (guint32 block_index, gboolean wait, gboolean *have_checked)
1590 gboolean have_live = FALSE;
1591 gboolean have_free = FALSE;
1597 volatile gpointer *block_slot = sgen_array_list_get_slot (&allocated_blocks, block_index);
1599 SGEN_ASSERT (6, sweep_in_progress (), "Why do we call this function if there's no sweep in progress?");
1602 *have_checked = FALSE;
1605 tagged_block = *(void * volatile *)block_slot;
1609 if (BLOCK_IS_TAGGED_CHECKING (tagged_block)) {
1612 /* FIXME: do this more elegantly */
1617 if (SGEN_CAS_PTR (block_slot, BLOCK_TAG_CHECKING (tagged_block), tagged_block) != tagged_block)
1620 block = BLOCK_UNTAG (tagged_block);
1621 block_state = block->state;
1623 if (!sweep_in_progress ()) {
1624 SGEN_ASSERT (6, block_state != BLOCK_STATE_SWEEPING && block_state != BLOCK_STATE_CHECKING, "Invalid block state.");
1626 SGEN_ASSERT (6, block_state != BLOCK_STATE_NEED_SWEEPING, "Invalid block state.");
1629 switch (block_state) {
1630 case BLOCK_STATE_SWEPT:
1631 case BLOCK_STATE_NEED_SWEEPING:
1632 case BLOCK_STATE_SWEEPING:
1634 case BLOCK_STATE_MARKING:
1636 case BLOCK_STATE_CHECKING:
1637 SGEN_ASSERT (0, FALSE, "We set the CHECKING bit - how can the stage be CHECKING?");
1640 SGEN_ASSERT (0, FALSE, "Illegal block state");
1644 SGEN_ASSERT (6, block->state == BLOCK_STATE_MARKING, "When we sweep all blocks must start out marking.");
1645 set_block_state (block, BLOCK_STATE_CHECKING, BLOCK_STATE_MARKING);
1648 *have_checked = TRUE;
1650 block->has_pinned = block->pinned;
1652 block->is_to_space = FALSE;
1654 count = MS_BLOCK_FREE / block->obj_size;
1656 if (block->cardtable_mod_union)
1657 memset (block->cardtable_mod_union, 0, CARDS_PER_BLOCK);
1659 /* Count marked objects in the block */
1660 for (i = 0; i < MS_NUM_MARK_WORDS; ++i)
1661 nused += bitcount (block->mark_words [i]);
1663 block->nused = nused;
1670 int obj_size_index = block->obj_size_index;
1671 gboolean has_pinned = block->has_pinned;
1673 set_block_state (block, BLOCK_STATE_NEED_SWEEPING, BLOCK_STATE_CHECKING);
1676 * FIXME: Go straight to SWEPT if there are no free slots. We need
1677 * to set the free slot list to NULL, though, and maybe update some
1681 sweep_block (block);
1684 ++sweep_num_blocks [obj_size_index];
1685 sweep_slots_used [obj_size_index] += nused;
1686 sweep_slots_available [obj_size_index] += count;
1690 * If there are free slots in the block, add
1691 * the block to the corresponding free list.
1694 MSBlockInfo * volatile *free_blocks = FREE_BLOCKS (block->pinned, block->has_references);
1697 SGEN_ASSERT (6, block->free_list, "How do we not have a free list when there are free slots?");
1699 add_free_block (free_blocks, obj_size_index, block);
1702 /* FIXME: Do we need the heap boundaries while we do nursery collections? */
1703 update_heap_boundaries_for_block (block);
1706 * Blocks without live objects are removed from the
1707 * block list and freed.
1709 SGEN_ASSERT (6, block_index < allocated_blocks.next_slot, "How did the number of blocks shrink?");
1710 SGEN_ASSERT (6, *block_slot == BLOCK_TAG_CHECKING (tagged_block), "How did the block move?");
1712 binary_protocol_empty (MS_BLOCK_OBJ (block, 0), (char*)MS_BLOCK_OBJ (block, count) - (char*)MS_BLOCK_OBJ (block, 0));
1713 ms_free_block (block);
1715 SGEN_ATOMIC_ADD_P (num_major_sections, -1);
1716 SGEN_ATOMIC_ADD_P (num_major_sections_freed_in_sweep, 1);
1718 tagged_block = NULL;
1723 * Once the block is written back without the checking bit other threads are
1724 * free to access it. Make sure the block state is visible before we write it
1727 mono_memory_write_barrier ();
1728 *block_slot = tagged_block;
1729 return !!tagged_block;
1733 sweep_blocks_job_func (void *thread_data_untyped, SgenThreadPoolJob *job)
1735 volatile gpointer *slot;
1738 SGEN_ARRAY_LIST_FOREACH_SLOT (&allocated_blocks, slot) {
1739 bl = BLOCK_UNTAG (*slot);
1742 } SGEN_ARRAY_LIST_END_FOREACH_SLOT;
1744 mono_memory_write_barrier ();
1746 sweep_blocks_job = NULL;
1750 sweep_job_func (void *thread_data_untyped, SgenThreadPoolJob *job)
1752 guint32 block_index;
1753 guint32 num_blocks = num_major_sections_before_sweep;
1755 SGEN_ASSERT (0, sweep_in_progress (), "Sweep thread called with wrong state");
1756 SGEN_ASSERT (0, num_blocks <= allocated_blocks.next_slot, "How did we lose blocks?");
1759 * We traverse the block array from high to low. Nursery collections will have to
1760 * cooperate with the sweep thread to finish sweeping, and they will traverse from
1761 * low to high, to avoid constantly colliding on the same blocks.
1763 for (block_index = allocated_blocks.next_slot; block_index-- > 0;) {
1764 ensure_block_is_checked_for_sweeping (block_index, TRUE, NULL);
1767 while (!try_set_sweep_state (SWEEP_STATE_COMPACTING, SWEEP_STATE_SWEEPING)) {
1769 * The main GC thread is currently iterating over the block array to help us
1770 * finish the sweep. We have already finished, but we don't want to mess up
1771 * that iteration, so we just wait for it.
1776 if (SGEN_MAX_ASSERT_LEVEL >= 6) {
1777 for (block_index = num_blocks; block_index < allocated_blocks.next_slot; ++block_index) {
1778 MSBlockInfo *block = BLOCK_UNTAG (*sgen_array_list_get_slot (&allocated_blocks, block_index));
1779 SGEN_ASSERT (6, block && block->state == BLOCK_STATE_SWEPT, "How did a new block to be swept get added while swept?");
1784 * Concurrently sweep all the blocks to reduce workload during minor
1785 * pauses where we need certain blocks to be swept. At the start of
1786 * the next major we need all blocks to be swept anyway.
1788 if (concurrent_sweep && lazy_sweep) {
1789 sweep_blocks_job = sgen_thread_pool_job_alloc ("sweep_blocks", sweep_blocks_job_func, sizeof (SgenThreadPoolJob));
1790 sgen_thread_pool_job_enqueue (sweep_blocks_job);
1801 mword used_slots_size = 0;
1804 for (i = 0; i < num_block_obj_sizes; ++i) {
1805 float usage = (float)sweep_slots_used [i] / (float)sweep_slots_available [i];
1806 if (sweep_num_blocks [i] > 5 && usage < evacuation_threshold) {
1807 evacuate_block_obj_sizes [i] = TRUE;
1809 g_print ("slot size %d - %d of %d used\n",
1810 block_obj_sizes [i], slots_used [i], slots_available [i]);
1813 evacuate_block_obj_sizes [i] = FALSE;
1816 used_slots_size += sweep_slots_used [i] * block_obj_sizes [i];
1819 sgen_memgov_major_post_sweep (used_slots_size);
1821 set_sweep_state (SWEEP_STATE_SWEPT, SWEEP_STATE_COMPACTING);
1822 if (concurrent_sweep)
1823 binary_protocol_concurrent_sweep_end (sgen_timestamp ());
1829 set_sweep_state (SWEEP_STATE_SWEEPING, SWEEP_STATE_NEED_SWEEPING);
1833 num_major_sections_before_sweep = num_major_sections;
1834 num_major_sections_freed_in_sweep = 0;
1836 SGEN_ASSERT (0, !sweep_job, "We haven't finished the last sweep?");
1837 if (concurrent_sweep) {
1838 sweep_job = sgen_thread_pool_job_alloc ("sweep", sweep_job_func, sizeof (SgenThreadPoolJob));
1839 sgen_thread_pool_job_enqueue (sweep_job);
1841 sweep_job_func (NULL, NULL);
1846 major_have_swept (void)
1848 return sweep_state == SWEEP_STATE_SWEPT;
1851 static int count_pinned_ref;
1852 static int count_pinned_nonref;
1853 static int count_nonpinned_ref;
1854 static int count_nonpinned_nonref;
1857 count_nonpinned_callback (GCObject *obj, size_t size, void *data)
1859 GCVTable vtable = SGEN_LOAD_VTABLE (obj);
1861 if (SGEN_VTABLE_HAS_REFERENCES (vtable))
1862 ++count_nonpinned_ref;
1864 ++count_nonpinned_nonref;
1868 count_pinned_callback (GCObject *obj, size_t size, void *data)
1870 GCVTable vtable = SGEN_LOAD_VTABLE (obj);
1872 if (SGEN_VTABLE_HAS_REFERENCES (vtable))
1875 ++count_pinned_nonref;
1878 static G_GNUC_UNUSED void
1879 count_ref_nonref_objs (void)
1883 count_pinned_ref = 0;
1884 count_pinned_nonref = 0;
1885 count_nonpinned_ref = 0;
1886 count_nonpinned_nonref = 0;
1888 major_iterate_objects (ITERATE_OBJECTS_SWEEP_NON_PINNED, count_nonpinned_callback, NULL);
1889 major_iterate_objects (ITERATE_OBJECTS_SWEEP_PINNED, count_pinned_callback, NULL);
1891 total = count_pinned_nonref + count_nonpinned_nonref + count_pinned_ref + count_nonpinned_ref;
1893 g_print ("ref: %d pinned %d non-pinned non-ref: %d pinned %d non-pinned -- %.1f\n",
1894 count_pinned_ref, count_nonpinned_ref,
1895 count_pinned_nonref, count_nonpinned_nonref,
1896 (count_pinned_nonref + count_nonpinned_nonref) * 100.0 / total);
1900 ms_calculate_block_obj_sizes (double factor, int *arr)
1907 * Have every possible slot size starting with the minimal
1908 * object size up to and including four times that size. Then
1909 * proceed by increasing geometrically with the given factor.
1912 for (int size = SGEN_CLIENT_MINIMUM_OBJECT_SIZE; size <= 4 * SGEN_CLIENT_MINIMUM_OBJECT_SIZE; size += SGEN_ALLOC_ALIGN) {
1914 arr [num_sizes] = size;
1918 target_size = (double)last_size;
1921 int target_count = (int)floor (MS_BLOCK_FREE / target_size);
1922 int size = MIN ((MS_BLOCK_FREE / target_count) & ~(SGEN_ALLOC_ALIGN - 1), SGEN_MAX_SMALL_OBJ_SIZE);
1924 if (size != last_size) {
1926 arr [num_sizes] = size;
1931 target_size *= factor;
1932 } while (last_size < SGEN_MAX_SMALL_OBJ_SIZE);
1937 /* only valid during minor collections */
1938 static mword old_num_major_sections;
1941 major_start_nursery_collection (void)
1943 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1944 consistency_check ();
1947 old_num_major_sections = num_major_sections;
1951 major_finish_nursery_collection (void)
1953 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1954 consistency_check ();
1959 block_usage_comparer (const void *bl1, const void *bl2)
1961 const gint16 nused1 = (*(MSBlockInfo**)bl1)->nused;
1962 const gint16 nused2 = (*(MSBlockInfo**)bl2)->nused;
1964 return nused2 - nused1;
1968 sgen_evacuation_freelist_blocks (MSBlockInfo * volatile *block_list, int size_index)
1970 MSBlockInfo **evacuated_blocks;
1971 size_t index = 0, count, num_blocks = 0, num_used = 0;
1973 MSBlockInfo * volatile *prev;
1975 for (info = *block_list; info != NULL; info = info->next_free) {
1977 num_used += info->nused;
1981 * We have a set of blocks in the freelist which will be evacuated. Instead
1982 * of evacuating all of the blocks into new ones, we traverse the freelist
1983 * sorting it by the number of occupied slots, evacuating the objects from
1984 * blocks with fewer used slots into fuller blocks.
1986 * The number of used slots is set at the end of the previous sweep. Since
1987 * we sequentially unlink slots from blocks, except for the head of the
1988 * freelist, for blocks on the freelist, the number of used slots is the same
1989 * as at the end of the previous sweep.
1991 evacuated_blocks = (MSBlockInfo**)sgen_alloc_internal_dynamic (sizeof (MSBlockInfo*) * num_blocks, INTERNAL_MEM_TEMPORARY, TRUE);
1993 for (info = *block_list; info != NULL; info = info->next_free) {
1994 evacuated_blocks [index++] = info;
1997 SGEN_ASSERT (0, num_blocks == index, "Why did the freelist change ?");
1999 sgen_qsort (evacuated_blocks, num_blocks, sizeof (gpointer), block_usage_comparer);
2002 * Form a new freelist with the fullest blocks. These blocks will also be
2003 * marked as to_space so we don't evacuate from them.
2005 count = MS_BLOCK_FREE / block_obj_sizes [size_index];
2007 for (index = 0; index < (num_used + count - 1) / count; index++) {
2008 SGEN_ASSERT (0, index < num_blocks, "Why do we need more blocks for compaction than we already had ?");
2009 info = evacuated_blocks [index];
2010 info->is_to_space = TRUE;
2012 prev = &info->next_free;
2016 sgen_free_internal_dynamic (evacuated_blocks, sizeof (MSBlockInfo*) * num_blocks, INTERNAL_MEM_TEMPORARY);
2020 major_start_major_collection (void)
2025 major_finish_sweep_checking ();
2028 * Clear the free lists for block sizes where we do evacuation. For those block
2029 * sizes we will have to allocate new blocks.
2031 for (i = 0; i < num_block_obj_sizes; ++i) {
2032 if (!evacuate_block_obj_sizes [i])
2035 binary_protocol_evacuating_blocks (block_obj_sizes [i]);
2037 sgen_evacuation_freelist_blocks (&free_block_lists [0][i], i);
2038 sgen_evacuation_freelist_blocks (&free_block_lists [MS_BLOCK_FLAG_REFS][i], i);
2041 if (lazy_sweep && concurrent_sweep) {
2043 * sweep_blocks_job is created before sweep_finish, which we wait for above
2044 * (major_finish_sweep_checking). After the end of sweep, if we don't have
2045 * sweep_blocks_job set, it means that it has already been run.
2047 SgenThreadPoolJob *job = sweep_blocks_job;
2049 sgen_thread_pool_job_wait (job);
2052 if (lazy_sweep && !concurrent_sweep)
2053 binary_protocol_sweep_begin (GENERATION_OLD, TRUE);
2054 /* Sweep all unswept blocks and set them to MARKING */
2055 FOREACH_BLOCK_NO_LOCK (block) {
2056 if (lazy_sweep && !concurrent_sweep)
2057 sweep_block (block);
2058 SGEN_ASSERT (0, block->state == BLOCK_STATE_SWEPT, "All blocks must be swept when we're pinning.");
2059 set_block_state (block, BLOCK_STATE_MARKING, BLOCK_STATE_SWEPT);
2061 * Swept blocks that have a null free_list are full. Evacuation is not
2062 * effective on these blocks since we expect them to have high usage anyway,
2063 * given that the survival rate for majors is relatively high.
2065 if (evacuate_block_obj_sizes [block->obj_size_index] && !block->free_list)
2066 block->is_to_space = TRUE;
2067 } END_FOREACH_BLOCK_NO_LOCK;
2068 if (lazy_sweep && !concurrent_sweep)
2069 binary_protocol_sweep_end (GENERATION_OLD, TRUE);
2071 set_sweep_state (SWEEP_STATE_NEED_SWEEPING, SWEEP_STATE_SWEPT);
2075 major_finish_major_collection (ScannedObjectCounts *counts)
2077 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
2078 if (binary_protocol_is_enabled ()) {
2079 counts->num_scanned_objects = scanned_objects_list.next_slot;
2081 sgen_pointer_queue_sort_uniq (&scanned_objects_list);
2082 counts->num_unique_scanned_objects = scanned_objects_list.next_slot;
2084 sgen_pointer_queue_clear (&scanned_objects_list);
2090 compare_pointers (const void *va, const void *vb) {
2091 char *a = *(char**)va, *b = *(char**)vb;
2100 * This is called with sweep completed and the world stopped.
2103 major_free_swept_blocks (size_t section_reserve)
2105 SGEN_ASSERT (0, sweep_state == SWEEP_STATE_SWEPT, "Sweeping must have finished before freeing blocks");
2109 * sgen_free_os_memory () asserts in mono_vfree () because windows doesn't like freeing the middle of
2110 * a VirtualAlloc ()-ed block.
2116 int i, num_empty_blocks_orig, num_blocks, arr_length;
2118 void **empty_block_arr;
2119 void **rebuild_next;
2121 if (num_empty_blocks <= section_reserve)
2123 SGEN_ASSERT (0, num_empty_blocks > 0, "section reserve can't be negative");
2125 num_empty_blocks_orig = num_empty_blocks;
2126 empty_block_arr = (void**)sgen_alloc_internal_dynamic (sizeof (void*) * num_empty_blocks_orig,
2127 INTERNAL_MEM_MS_BLOCK_INFO_SORT, FALSE);
2128 if (!empty_block_arr)
2132 for (block = empty_blocks; block; block = *(void**)block)
2133 empty_block_arr [i++] = block;
2134 SGEN_ASSERT (0, i == num_empty_blocks, "empty block count wrong");
2136 sgen_qsort (empty_block_arr, num_empty_blocks, sizeof (void*), compare_pointers);
2139 * We iterate over the free blocks, trying to find MS_BLOCK_ALLOC_NUM
2140 * contiguous ones. If we do, we free them. If that's not enough to get to
2141 * section_reserve, we halve the number of contiguous blocks we're looking
2142 * for and have another go, until we're done with looking for pairs of
2143 * blocks, at which point we give up and go to the fallback.
2145 arr_length = num_empty_blocks_orig;
2146 num_blocks = MS_BLOCK_ALLOC_NUM;
2147 while (num_empty_blocks > section_reserve && num_blocks > 1) {
2152 for (i = 0; i < arr_length; ++i) {
2154 void *block = empty_block_arr [i];
2155 SGEN_ASSERT (6, block, "we're not shifting correctly");
2157 empty_block_arr [dest] = block;
2159 * This is not strictly necessary, but we're
2162 empty_block_arr [i] = NULL;
2171 SGEN_ASSERT (6, first >= 0 && d > first, "algorithm is wrong");
2173 if ((char*)block != ((char*)empty_block_arr [d-1]) + MS_BLOCK_SIZE) {
2178 if (d + 1 - first == num_blocks) {
2180 * We found num_blocks contiguous blocks. Free them
2181 * and null their array entries. As an optimization
2182 * we could, instead of nulling the entries, shift
2183 * the following entries over to the left, while
2187 sgen_free_os_memory (empty_block_arr [first], MS_BLOCK_SIZE * num_blocks, SGEN_ALLOC_HEAP, MONO_MEM_ACCOUNT_SGEN_MARKSWEEP);
2188 for (j = first; j <= d; ++j)
2189 empty_block_arr [j] = NULL;
2193 num_empty_blocks -= num_blocks;
2195 stat_major_blocks_freed += num_blocks;
2196 if (num_blocks == MS_BLOCK_ALLOC_NUM)
2197 stat_major_blocks_freed_ideal += num_blocks;
2199 stat_major_blocks_freed_less_ideal += num_blocks;
2204 SGEN_ASSERT (6, dest <= i && dest <= arr_length, "array length is off");
2206 SGEN_ASSERT (6, arr_length == num_empty_blocks, "array length is off");
2211 /* rebuild empty_blocks free list */
2212 rebuild_next = (void**)&empty_blocks;
2213 for (i = 0; i < arr_length; ++i) {
2214 void *block = empty_block_arr [i];
2215 SGEN_ASSERT (6, block, "we're missing blocks");
2216 *rebuild_next = block;
2217 rebuild_next = (void**)block;
2219 *rebuild_next = NULL;
2222 sgen_free_internal_dynamic (empty_block_arr, sizeof (void*) * num_empty_blocks_orig, INTERNAL_MEM_MS_BLOCK_INFO_SORT);
2225 SGEN_ASSERT (0, num_empty_blocks >= 0, "we freed more blocks than we had in the first place?");
2229 * This is our threshold. If there's not more empty than used blocks, we won't
2230 * release uncontiguous blocks, in fear of fragmenting the address space.
2232 if (num_empty_blocks <= num_major_sections)
2235 while (num_empty_blocks > section_reserve) {
2236 void *next = *(void**)empty_blocks;
2237 sgen_free_os_memory (empty_blocks, MS_BLOCK_SIZE, SGEN_ALLOC_HEAP, MONO_MEM_ACCOUNT_SGEN_MARKSWEEP);
2238 empty_blocks = next;
2240 * Needs not be atomic because this is running
2245 ++stat_major_blocks_freed;
2246 ++stat_major_blocks_freed_individual;
2251 major_pin_objects (SgenGrayQueue *queue)
2255 FOREACH_BLOCK_NO_LOCK (block) {
2256 size_t first_entry, last_entry;
2257 SGEN_ASSERT (6, block_is_swept_or_marking (block), "All blocks must be swept when we're pinning.");
2258 sgen_find_optimized_pin_queue_area (MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SKIP, MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE,
2259 &first_entry, &last_entry);
2260 mark_pinned_objects_in_block (block, first_entry, last_entry, queue);
2261 } END_FOREACH_BLOCK_NO_LOCK;
2265 major_init_to_space (void)
2270 major_report_pinned_memory_usage (void)
2272 g_assert_not_reached ();
2276 major_get_used_size (void)
2282 * We're holding the GC lock, but the sweep thread might be running. Make sure it's
2283 * finished, then we can iterate over the block array.
2285 major_finish_sweep_checking ();
2287 FOREACH_BLOCK_NO_LOCK (block) {
2288 int count = MS_BLOCK_FREE / block->obj_size;
2290 size += count * block->obj_size;
2291 for (iter = block->free_list; iter; iter = (void**)*iter)
2292 size -= block->obj_size;
2293 } END_FOREACH_BLOCK_NO_LOCK;
2298 /* FIXME: return number of bytes, not of sections */
2300 get_num_major_sections (void)
2302 return num_major_sections;
2306 * Returns the number of bytes in blocks that were present when the last sweep was
2307 * initiated, and were not freed during the sweep. They are the basis for calculating the
2311 get_bytes_survived_last_sweep (void)
2313 SGEN_ASSERT (0, sweep_state == SWEEP_STATE_SWEPT, "Can only query unswept sections after sweep");
2314 return (num_major_sections_before_sweep - num_major_sections_freed_in_sweep) * MS_BLOCK_SIZE;
2318 major_handle_gc_param (const char *opt)
2320 if (g_str_has_prefix (opt, "evacuation-threshold=")) {
2321 const char *arg = strchr (opt, '=') + 1;
2322 int percentage = atoi (arg);
2323 if (percentage < 0 || percentage > 100) {
2324 fprintf (stderr, "evacuation-threshold must be an integer in the range 0-100.\n");
2327 evacuation_threshold = (float)percentage / 100.0f;
2329 } else if (!strcmp (opt, "lazy-sweep")) {
2332 } else if (!strcmp (opt, "no-lazy-sweep")) {
2335 } else if (!strcmp (opt, "concurrent-sweep")) {
2336 concurrent_sweep = TRUE;
2338 } else if (!strcmp (opt, "no-concurrent-sweep")) {
2339 concurrent_sweep = FALSE;
2347 major_print_gc_param_usage (void)
2351 " evacuation-threshold=P (where P is a percentage, an integer in 0-100)\n"
2352 " (no-)lazy-sweep\n"
2353 " (no-)concurrent-sweep\n"
2358 * This callback is used to clear cards, move cards to the shadow table and do counting.
2361 major_iterate_block_ranges (sgen_cardtable_block_callback callback)
2364 gboolean has_references;
2366 FOREACH_BLOCK_HAS_REFERENCES_NO_LOCK (block, has_references) {
2368 callback ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE);
2369 } END_FOREACH_BLOCK_NO_LOCK;
2373 major_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
2376 gboolean has_references;
2378 major_finish_sweep_checking ();
2379 FOREACH_BLOCK_HAS_REFERENCES_NO_LOCK (block, has_references) {
2381 callback ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE);
2382 } END_FOREACH_BLOCK_NO_LOCK;
2385 #ifdef HEAVY_STATISTICS
2386 extern guint64 marked_cards;
2387 extern guint64 scanned_cards;
2388 extern guint64 scanned_objects;
2389 extern guint64 remarked_cards;
2392 #define CARD_WORDS_PER_BLOCK (CARDS_PER_BLOCK / SIZEOF_VOID_P)
2394 * MS blocks are 16K aligned.
2395 * Cardtables are 4K aligned, at least.
2396 * This means that the cardtable of a given block is 32 bytes aligned.
2399 initial_skip_card (guint8 *card_data)
2401 mword *cards = (mword*)card_data;
2404 for (i = 0; i < CARD_WORDS_PER_BLOCK; ++i) {
2410 if (i == CARD_WORDS_PER_BLOCK)
2411 return card_data + CARDS_PER_BLOCK;
2413 #if defined(__i386__) && defined(__GNUC__)
2414 return card_data + i * 4 + (__builtin_ffs (card) - 1) / 8;
2415 #elif defined(__x86_64__) && defined(__GNUC__)
2416 return card_data + i * 8 + (__builtin_ffsll (card) - 1) / 8;
2417 #elif defined(__s390x__) && defined(__GNUC__)
2418 return card_data + i * 8 + (__builtin_ffsll (GUINT64_TO_LE(card)) - 1) / 8;
2420 for (i = i * SIZEOF_VOID_P; i < CARDS_PER_BLOCK; ++i) {
2422 return &card_data [i];
2428 #define MS_BLOCK_OBJ_INDEX_FAST(o,b,os) (((char*)(o) - ((b) + MS_BLOCK_SKIP)) / (os))
2429 #define MS_BLOCK_OBJ_FAST(b,os,i) ((b) + MS_BLOCK_SKIP + (os) * (i))
2430 #define MS_OBJ_ALLOCED_FAST(o,b) (*(void**)(o) && (*(char**)(o) < (b) || *(char**)(o) >= (b) + MS_BLOCK_SIZE))
2433 scan_card_table_for_block (MSBlockInfo *block, CardTableScanType scan_type, ScanCopyContext ctx)
2435 SgenGrayQueue *queue = ctx.queue;
2436 ScanObjectFunc scan_func = ctx.ops->scan_object;
2437 #ifndef SGEN_HAVE_OVERLAPPING_CARDS
2438 guint8 cards_copy [CARDS_PER_BLOCK];
2440 guint8 cards_preclean [CARDS_PER_BLOCK];
2441 gboolean small_objects;
2444 guint8 *card_data, *card_base;
2445 guint8 *card_data_end;
2446 char *scan_front = NULL;
2448 /* The concurrent mark doesn't enter evacuating blocks */
2449 if (scan_type == CARDTABLE_SCAN_MOD_UNION_PRECLEAN && major_block_is_evacuating (block))
2452 block_obj_size = block->obj_size;
2453 small_objects = block_obj_size < CARD_SIZE_IN_BYTES;
2455 block_start = MS_BLOCK_FOR_BLOCK_INFO (block);
2458 * This is safe in face of card aliasing for the following reason:
2460 * Major blocks are 16k aligned, or 32 cards aligned.
2461 * Cards aliasing happens in powers of two, so as long as major blocks are aligned to their
2462 * sizes, they won't overflow the cardtable overlap modulus.
2464 if (scan_type & CARDTABLE_SCAN_MOD_UNION) {
2465 card_data = card_base = block->cardtable_mod_union;
2467 * This happens when the nursery collection that precedes finishing
2468 * the concurrent collection allocates new major blocks.
2473 if (scan_type == CARDTABLE_SCAN_MOD_UNION_PRECLEAN) {
2474 sgen_card_table_preclean_mod_union (card_data, cards_preclean, CARDS_PER_BLOCK);
2475 card_data = card_base = cards_preclean;
2478 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
2479 card_data = card_base = sgen_card_table_get_card_scan_address ((mword)block_start);
2481 if (!sgen_card_table_get_card_data (cards_copy, (mword)block_start, CARDS_PER_BLOCK))
2483 card_data = card_base = cards_copy;
2486 card_data_end = card_data + CARDS_PER_BLOCK;
2488 card_data += MS_BLOCK_SKIP >> CARD_BITS;
2490 card_data = initial_skip_card (card_data);
2491 while (card_data < card_data_end) {
2492 size_t card_index, first_object_index;
2495 char *first_obj, *obj;
2497 HEAVY_STAT (++scanned_cards);
2504 card_index = card_data - card_base;
2505 start = (char*)(block_start + card_index * CARD_SIZE_IN_BYTES);
2506 end = start + CARD_SIZE_IN_BYTES;
2508 if (!block_is_swept_or_marking (block))
2509 sweep_block (block);
2511 HEAVY_STAT (++marked_cards);
2514 sgen_card_table_prepare_card_for_scanning (card_data);
2517 * If the card we're looking at starts at or in the block header, we
2518 * must start at the first object in the block, without calculating
2519 * the index of the object we're hypothetically starting at, because
2520 * it would be negative.
2522 if (card_index <= (MS_BLOCK_SKIP >> CARD_BITS))
2523 first_object_index = 0;
2525 first_object_index = MS_BLOCK_OBJ_INDEX_FAST (start, block_start, block_obj_size);
2527 obj = first_obj = (char*)MS_BLOCK_OBJ_FAST (block_start, block_obj_size, first_object_index);
2529 binary_protocol_card_scan (first_obj, end - first_obj);
2532 if (obj < scan_front || !MS_OBJ_ALLOCED_FAST (obj, block_start))
2535 if (scan_type & CARDTABLE_SCAN_MOD_UNION) {
2536 /* FIXME: do this more efficiently */
2538 MS_CALC_MARK_BIT (w, b, obj);
2539 if (!MS_MARK_BIT (block, w, b))
2543 GCObject *object = (GCObject*)obj;
2545 if (small_objects) {
2546 HEAVY_STAT (++scanned_objects);
2547 scan_func (object, sgen_obj_get_descriptor (object), queue);
2549 size_t offset = sgen_card_table_get_card_offset (obj, block_start);
2550 sgen_cardtable_scan_object (object, block_obj_size, card_base + offset, ctx);
2553 obj += block_obj_size;
2554 g_assert (scan_front <= obj);
2558 HEAVY_STAT (if (*card_data) ++remarked_cards);
2563 card_data = card_base + sgen_card_table_get_card_offset (obj, block_start);
2568 major_scan_card_table (CardTableScanType scan_type, ScanCopyContext ctx, int job_index, int job_split_count)
2571 gboolean has_references, was_sweeping, skip_scan;
2573 if (!concurrent_mark)
2574 g_assert (scan_type == CARDTABLE_SCAN_GLOBAL);
2576 if (scan_type != CARDTABLE_SCAN_GLOBAL)
2577 SGEN_ASSERT (0, !sweep_in_progress (), "Sweep should be finished when we scan mod union card table");
2578 was_sweeping = sweep_in_progress ();
2580 binary_protocol_major_card_table_scan_start (sgen_timestamp (), scan_type & CARDTABLE_SCAN_MOD_UNION);
2581 FOREACH_BLOCK_HAS_REFERENCES_NO_LOCK (block, has_references) {
2582 if (__index % job_split_count != job_index)
2584 #ifdef PREFETCH_CARDS
2585 int prefetch_index = __index + 6 * job_split_count;
2586 if (prefetch_index < allocated_blocks.next_slot) {
2587 MSBlockInfo *prefetch_block = BLOCK_UNTAG (*sgen_array_list_get_slot (&allocated_blocks, prefetch_index));
2588 PREFETCH_READ (prefetch_block);
2589 if (scan_type == CARDTABLE_SCAN_GLOBAL) {
2590 guint8 *prefetch_cards = sgen_card_table_get_card_scan_address ((mword)MS_BLOCK_FOR_BLOCK_INFO (prefetch_block));
2591 PREFETCH_WRITE (prefetch_cards);
2592 PREFETCH_WRITE (prefetch_cards + 32);
2597 if (!has_references)
2601 if (scan_type == CARDTABLE_SCAN_GLOBAL) {
2602 gpointer *card_start = (gpointer*) sgen_card_table_get_card_scan_address ((mword)MS_BLOCK_FOR_BLOCK_INFO (block));
2603 gboolean has_dirty_cards = FALSE;
2605 for (i = 0; i < CARDS_PER_BLOCK / sizeof(gpointer); i++) {
2606 if (card_start [i]) {
2607 has_dirty_cards = TRUE;
2611 if (!has_dirty_cards) {
2615 * After the start of the concurrent collections, blocks change state
2616 * to marking. We should not sweep it in that case. We can't race with
2617 * sweep start since we are in a nursery collection. Also avoid CAS-ing
2619 if (sweep_in_progress ()) {
2620 skip_scan = !ensure_block_is_checked_for_sweeping (__index, TRUE, NULL);
2621 } else if (was_sweeping) {
2622 /* Recheck in case sweep finished after dereferencing the slot */
2623 skip_scan = *sgen_array_list_get_slot (&allocated_blocks, __index) == 0;
2628 scan_card_table_for_block (block, scan_type, ctx);
2629 } END_FOREACH_BLOCK_NO_LOCK;
2630 binary_protocol_major_card_table_scan_end (sgen_timestamp (), scan_type & CARDTABLE_SCAN_MOD_UNION);
2634 major_count_cards (long long *num_total_cards, long long *num_marked_cards)
2637 gboolean has_references;
2638 long long total_cards = 0;
2639 long long marked_cards = 0;
2641 if (sweep_in_progress ()) {
2642 *num_total_cards = -1;
2643 *num_marked_cards = -1;
2647 FOREACH_BLOCK_HAS_REFERENCES_NO_LOCK (block, has_references) {
2648 guint8 *cards = sgen_card_table_get_card_scan_address ((mword) MS_BLOCK_FOR_BLOCK_INFO (block));
2651 if (!has_references)
2654 total_cards += CARDS_PER_BLOCK;
2655 for (i = 0; i < CARDS_PER_BLOCK; ++i) {
2659 } END_FOREACH_BLOCK_NO_LOCK;
2661 *num_total_cards = total_cards;
2662 *num_marked_cards = marked_cards;
2666 update_cardtable_mod_union (void)
2670 FOREACH_BLOCK_NO_LOCK (block) {
2671 gpointer *card_start = (gpointer*) sgen_card_table_get_card_address ((mword)MS_BLOCK_FOR_BLOCK_INFO (block));
2672 gboolean has_dirty_cards = FALSE;
2674 for (i = 0; i < CARDS_PER_BLOCK / sizeof(gpointer); i++) {
2675 if (card_start [i]) {
2676 has_dirty_cards = TRUE;
2680 if (has_dirty_cards) {
2682 guint8 *mod_union = get_cardtable_mod_union_for_block (block, TRUE);
2683 sgen_card_table_update_mod_union (mod_union, MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE, &num_cards);
2684 SGEN_ASSERT (6, num_cards == CARDS_PER_BLOCK, "Number of cards calculation is wrong");
2686 } END_FOREACH_BLOCK_NO_LOCK;
2689 #undef pthread_create
2692 post_param_init (SgenMajorCollector *collector)
2694 collector->sweeps_lazily = lazy_sweep;
2695 collector->needs_thread_pool = concurrent_mark || concurrent_sweep;
2698 /* We are guaranteed to be called by the worker in question */
2700 sgen_worker_init_callback (gpointer worker_untyped)
2703 WorkerData *worker = (WorkerData*) worker_untyped;
2704 MSBlockInfo ***worker_free_blocks = (MSBlockInfo ***) sgen_alloc_internal_dynamic (sizeof (MSBlockInfo**) * MS_BLOCK_TYPE_MAX, INTERNAL_MEM_MS_TABLES, TRUE);
2706 for (i = 0; i < MS_BLOCK_TYPE_MAX; i++)
2707 worker_free_blocks [i] = (MSBlockInfo **) sgen_alloc_internal_dynamic (sizeof (MSBlockInfo*) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2709 worker->free_block_lists = worker_free_blocks;
2711 mono_native_tls_set_value (worker_block_free_list_key, worker_free_blocks);
2715 sgen_marksweep_init_internal (SgenMajorCollector *collector, gboolean is_concurrent, gboolean is_parallel)
2719 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_MS_BLOCK_INFO, sizeof (MSBlockInfo));
2721 num_block_obj_sizes = ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, NULL);
2722 block_obj_sizes = (int *)sgen_alloc_internal_dynamic (sizeof (int) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2723 ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, block_obj_sizes);
2725 evacuate_block_obj_sizes = (gboolean *)sgen_alloc_internal_dynamic (sizeof (gboolean) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2726 for (i = 0; i < num_block_obj_sizes; ++i)
2727 evacuate_block_obj_sizes [i] = FALSE;
2729 sweep_slots_available = (size_t *)sgen_alloc_internal_dynamic (sizeof (size_t) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2730 sweep_slots_used = (size_t *)sgen_alloc_internal_dynamic (sizeof (size_t) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2731 sweep_num_blocks = (size_t *)sgen_alloc_internal_dynamic (sizeof (size_t) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2736 g_print ("block object sizes:\n");
2737 for (i = 0; i < num_block_obj_sizes; ++i)
2738 g_print ("%d\n", block_obj_sizes [i]);
2742 for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i)
2743 free_block_lists [i] = (MSBlockInfo *volatile *)sgen_alloc_internal_dynamic (sizeof (MSBlockInfo*) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2745 for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES; ++i)
2746 fast_block_obj_size_indexes [i] = ms_find_block_obj_size_index (i * 8);
2747 for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES * 8; ++i)
2748 g_assert (MS_BLOCK_OBJ_SIZE_INDEX (i) == ms_find_block_obj_size_index (i));
2750 mono_counters_register ("# major blocks allocated", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_major_blocks_alloced);
2751 mono_counters_register ("# major blocks freed", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_major_blocks_freed);
2752 mono_counters_register ("# major blocks lazy swept", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_major_blocks_lazy_swept);
2753 mono_counters_register ("# major blocks freed ideally", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_major_blocks_freed_ideal);
2754 mono_counters_register ("# major blocks freed less ideally", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_major_blocks_freed_less_ideal);
2755 mono_counters_register ("# major blocks freed individually", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_major_blocks_freed_individual);
2756 mono_counters_register ("# major blocks allocated less ideally", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_major_blocks_alloced_less_ideal);
2758 collector->section_size = MAJOR_SECTION_SIZE;
2760 concurrent_mark = is_concurrent;
2761 collector->is_concurrent = is_concurrent;
2762 collector->is_parallel = is_parallel;
2763 collector->needs_thread_pool = is_concurrent || concurrent_sweep;
2764 collector->get_and_reset_num_major_objects_marked = major_get_and_reset_num_major_objects_marked;
2765 collector->supports_cardtable = TRUE;
2767 collector->alloc_heap = major_alloc_heap;
2768 collector->is_object_live = major_is_object_live;
2769 collector->alloc_small_pinned_obj = major_alloc_small_pinned_obj;
2770 collector->alloc_degraded = major_alloc_degraded;
2772 collector->alloc_object = major_alloc_object;
2773 collector->alloc_object_par = major_alloc_object_par;
2774 collector->free_pinned_object = free_pinned_object;
2775 collector->iterate_objects = major_iterate_objects;
2776 collector->free_non_pinned_object = major_free_non_pinned_object;
2777 collector->pin_objects = major_pin_objects;
2778 collector->pin_major_object = pin_major_object;
2779 collector->scan_card_table = major_scan_card_table;
2780 collector->iterate_live_block_ranges = major_iterate_live_block_ranges;
2781 collector->iterate_block_ranges = major_iterate_block_ranges;
2782 if (is_concurrent) {
2783 collector->update_cardtable_mod_union = update_cardtable_mod_union;
2784 collector->get_cardtable_mod_union_for_reference = major_get_cardtable_mod_union_for_reference;
2786 collector->init_to_space = major_init_to_space;
2787 collector->sweep = major_sweep;
2788 collector->have_swept = major_have_swept;
2789 collector->finish_sweeping = major_finish_sweep_checking;
2790 collector->free_swept_blocks = major_free_swept_blocks;
2791 collector->check_scan_starts = major_check_scan_starts;
2792 collector->dump_heap = major_dump_heap;
2793 collector->get_used_size = major_get_used_size;
2794 collector->start_nursery_collection = major_start_nursery_collection;
2795 collector->finish_nursery_collection = major_finish_nursery_collection;
2796 collector->start_major_collection = major_start_major_collection;
2797 collector->finish_major_collection = major_finish_major_collection;
2798 collector->ptr_is_in_non_pinned_space = major_ptr_is_in_non_pinned_space;
2799 collector->ptr_is_from_pinned_alloc = ptr_is_from_pinned_alloc;
2800 collector->report_pinned_memory_usage = major_report_pinned_memory_usage;
2801 collector->get_num_major_sections = get_num_major_sections;
2802 collector->get_bytes_survived_last_sweep = get_bytes_survived_last_sweep;
2803 collector->handle_gc_param = major_handle_gc_param;
2804 collector->print_gc_param_usage = major_print_gc_param_usage;
2805 collector->post_param_init = post_param_init;
2806 collector->is_valid_object = major_is_valid_object;
2807 collector->describe_pointer = major_describe_pointer;
2808 collector->count_cards = major_count_cards;
2810 collector->major_ops_serial.copy_or_mark_object = major_copy_or_mark_object_canonical;
2811 collector->major_ops_serial.scan_object = major_scan_object_with_evacuation;
2812 collector->major_ops_serial.drain_gray_stack = drain_gray_stack;
2813 if (is_concurrent) {
2814 collector->major_ops_concurrent_start.copy_or_mark_object = major_copy_or_mark_object_concurrent_canonical;
2815 collector->major_ops_concurrent_start.scan_object = major_scan_object_concurrent_with_evacuation;
2816 collector->major_ops_concurrent_start.scan_vtype = major_scan_vtype_concurrent_with_evacuation;
2817 collector->major_ops_concurrent_start.scan_ptr_field = major_scan_ptr_field_concurrent_with_evacuation;
2818 collector->major_ops_concurrent_start.drain_gray_stack = drain_gray_stack_concurrent;
2820 collector->major_ops_concurrent_finish.copy_or_mark_object = major_copy_or_mark_object_concurrent_finish_canonical;
2821 collector->major_ops_concurrent_finish.scan_object = major_scan_object_with_evacuation;
2822 collector->major_ops_concurrent_finish.scan_vtype = major_scan_vtype_with_evacuation;
2823 collector->major_ops_concurrent_finish.scan_ptr_field = major_scan_ptr_field_with_evacuation;
2824 collector->major_ops_concurrent_finish.drain_gray_stack = drain_gray_stack;
2827 collector->major_ops_conc_par_start.copy_or_mark_object = major_copy_or_mark_object_concurrent_par_canonical;
2828 collector->major_ops_conc_par_start.scan_object = major_scan_object_concurrent_par_with_evacuation;
2829 collector->major_ops_conc_par_start.scan_vtype = major_scan_vtype_concurrent_par_with_evacuation;
2830 collector->major_ops_conc_par_start.scan_ptr_field = major_scan_ptr_field_concurrent_par_with_evacuation;
2831 collector->major_ops_conc_par_start.drain_gray_stack = drain_gray_stack_concurrent_par;
2833 collector->major_ops_conc_par_finish.copy_or_mark_object = major_copy_or_mark_object_concurrent_par_finish_canonical;
2834 collector->major_ops_conc_par_finish.scan_object = major_scan_object_par_with_evacuation;
2835 collector->major_ops_conc_par_finish.scan_vtype = major_scan_vtype_par_with_evacuation;
2836 collector->major_ops_conc_par_finish.scan_ptr_field = major_scan_ptr_field_par_with_evacuation;
2837 collector->major_ops_conc_par_finish.drain_gray_stack = drain_gray_stack_par;
2839 collector->worker_init_cb = sgen_worker_init_callback;
2841 mono_native_tls_alloc (&worker_block_free_list_key, NULL);
2845 #ifdef HEAVY_STATISTICS
2846 mono_counters_register ("Optimized copy", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_copy);
2847 mono_counters_register ("Optimized copy nursery", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_copy_nursery);
2848 mono_counters_register ("Optimized copy nursery forwarded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_copy_nursery_forwarded);
2849 mono_counters_register ("Optimized copy nursery pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_copy_nursery_pinned);
2850 mono_counters_register ("Optimized copy major", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_copy_major);
2851 mono_counters_register ("Optimized copy major small fast", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_copy_major_small_fast);
2852 mono_counters_register ("Optimized copy major small slow", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_copy_major_small_slow);
2853 mono_counters_register ("Optimized copy major small evacuate", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_copy_major_small_evacuate);
2854 mono_counters_register ("Optimized copy major large", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_copy_major_large);
2855 mono_counters_register ("Optimized major scan", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_major_scan);
2856 mono_counters_register ("Optimized major scan no refs", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_optimized_major_scan_no_refs);
2858 mono_counters_register ("Gray stack drain loops", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_drain_loops);
2859 mono_counters_register ("Gray stack prefetch fills", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_drain_prefetch_fills);
2860 mono_counters_register ("Gray stack prefetch failures", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_drain_prefetch_fill_failures);
2863 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
2864 mono_os_mutex_init (&scanned_objects_list_lock);
2867 SGEN_ASSERT (0, SGEN_MAX_SMALL_OBJ_SIZE <= MS_BLOCK_FREE / 2, "MAX_SMALL_OBJ_SIZE must be at most MS_BLOCK_FREE / 2");
2869 /*cardtable requires major pages to be 8 cards aligned*/
2870 g_assert ((MS_BLOCK_SIZE % (8 * CARD_SIZE_IN_BYTES)) == 0);
2874 sgen_marksweep_init (SgenMajorCollector *collector)
2876 sgen_marksweep_init_internal (collector, FALSE, FALSE);
2880 sgen_marksweep_conc_init (SgenMajorCollector *collector)
2882 sgen_marksweep_init_internal (collector, TRUE, FALSE);
2886 sgen_marksweep_conc_par_init (SgenMajorCollector *collector)
2888 sgen_marksweep_init_internal (collector, TRUE, TRUE);