mono/metadata/sgen-marksweep.c

   1 /*
   2  * sgen-marksweep.c: The Mark & Sweep major collector.
   3  *
   4  * Author:
   5  *      Mark Probst <mark.probst@gmail.com>
   6  *
   7  * Copyright 2009-2010 Novell, Inc.
   8  * Copyright (C) 2012 Xamarin Inc
   9  *
  10  * This library is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Library General Public
  12  * License 2.0 as published by the Free Software Foundation;
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Library General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Library General Public
  20  * License 2.0 along with this library; if not, write to the Free
  21  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #include "config.h"
  25
  26 #ifdef HAVE_SGEN_GC
  27
  28 #include <math.h>
  29 #include <errno.h>
  30
  31 #include "utils/mono-counters.h"
  32 #include "utils/mono-semaphore.h"
  33 #include "utils/mono-time.h"
  34 #include "metadata/object-internals.h"
  35 #include "metadata/profiler-private.h"
  36
  37 #include "metadata/sgen-gc.h"
  38 #include "metadata/sgen-protocol.h"
  39 #include "metadata/sgen-cardtable.h"
  40 #include "metadata/sgen-memory-governor.h"
  41 #include "metadata/sgen-layout-stats.h"
  42 #include "metadata/gc-internal.h"
  43 #include "metadata/sgen-pointer-queue.h"
  44 #include "metadata/sgen-pinning.h"
  45 #include "metadata/sgen-workers.h"
  46
  47 #define SGEN_HAVE_CONCURRENT_MARK
  48
  49 #define MS_BLOCK_SIZE   (16*1024)
  50 #define MS_BLOCK_SIZE_SHIFT     14
  51 #define MAJOR_SECTION_SIZE      MS_BLOCK_SIZE
  52 #define CARDS_PER_BLOCK (MS_BLOCK_SIZE / CARD_SIZE_IN_BYTES)
  53
  54 /*
  55  * Don't allocate single blocks, but alloc a contingent of this many
  56  * blocks in one swoop.  This must be a power of two.
  57  */
  58 #define MS_BLOCK_ALLOC_NUM      32
  59
  60 /*
  61  * Number of bytes before the first object in a block.  At the start
  62  * of a block is the MSBlockHeader, then opional padding, then come
  63  * the objects, so this must be >= sizeof (MSBlockHeader).
  64  */
  65 #define MS_BLOCK_SKIP   ((sizeof (MSBlockHeader) + 15) & ~15)
  66
  67 #define MS_BLOCK_FREE   (MS_BLOCK_SIZE - MS_BLOCK_SKIP)
  68
  69 #define MS_NUM_MARK_WORDS       ((MS_BLOCK_SIZE / SGEN_ALLOC_ALIGN + sizeof (mword) * 8 - 1) / (sizeof (mword) * 8))
  70
  71 typedef struct _MSBlockInfo MSBlockInfo;
  72 struct _MSBlockInfo {
  73         int obj_size;
  74         int obj_size_index;
  75         unsigned int pinned : 1;
  76         unsigned int has_references : 1;
  77         unsigned int has_pinned : 1;    /* means cannot evacuate */
  78         unsigned int is_to_space : 1;
  79         unsigned int swept : 1;
  80         void **free_list;
  81         MSBlockInfo *next_free;
  82         size_t pin_queue_first_entry;
  83         size_t pin_queue_last_entry;
  84 #ifdef SGEN_HAVE_CONCURRENT_MARK
  85         guint8 *cardtable_mod_union;
  86 #endif
  87         mword mark_words [MS_NUM_MARK_WORDS];
  88 };
  89
  90 #define MS_BLOCK_FOR_BLOCK_INFO(b)      ((char*)(b))
  91
  92 #define MS_BLOCK_OBJ(b,i)               (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (b)->obj_size * (i))
  93 #define MS_BLOCK_OBJ_FOR_SIZE(b,i,obj_size)             (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (obj_size) * (i))
  94 #define MS_BLOCK_DATA_FOR_OBJ(o)        ((char*)((mword)(o) & ~(mword)(MS_BLOCK_SIZE - 1)))
  95
  96 typedef struct {
  97         MSBlockInfo info;
  98 } MSBlockHeader;
  99
 100 #define MS_BLOCK_FOR_OBJ(o)             (&((MSBlockHeader*)MS_BLOCK_DATA_FOR_OBJ ((o)))->info)
 101
 102 /* object index will always be small */
 103 #define MS_BLOCK_OBJ_INDEX(o,b) ((int)(((char*)(o) - (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP)) / (b)->obj_size))
 104
 105 //casting to int is fine since blocks are 32k
 106 #define MS_CALC_MARK_BIT(w,b,o)         do {                            \
 107                 int i = ((int)((char*)(o) - MS_BLOCK_DATA_FOR_OBJ ((o)))) >> SGEN_ALLOC_ALIGN_BITS; \
 108                 if (sizeof (mword) == 4) {                              \
 109                         (w) = i >> 5;                                   \
 110                         (b) = i & 31;                                   \
 111                 } else {                                                \
 112                         (w) = i >> 6;                                   \
 113                         (b) = i & 63;                                   \
 114                 }                                                       \
 115         } while (0)
 116
 117 #define MS_MARK_BIT(bl,w,b)     ((bl)->mark_words [(w)] & (ONE_P << (b)))
 118 #define MS_SET_MARK_BIT(bl,w,b) ((bl)->mark_words [(w)] |= (ONE_P << (b)))
 119
 120 #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))
 121
 122 #define MS_BLOCK_OBJ_SIZE_FACTOR        (sqrt (2.0))
 123
 124 /*
 125  * This way we can lookup block object size indexes for sizes up to
 126  * 256 bytes with a single load.
 127  */
 128 #define MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES      32
 129
 130 static int *block_obj_sizes;
 131 static int num_block_obj_sizes;
 132 static int fast_block_obj_size_indexes [MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES];
 133
 134 #define MS_BLOCK_FLAG_PINNED    1
 135 #define MS_BLOCK_FLAG_REFS      2
 136
 137 #define MS_BLOCK_TYPE_MAX       4
 138
 139 static gboolean *evacuate_block_obj_sizes;
 140 static float evacuation_threshold = 0.0f;
 141 #ifdef SGEN_HAVE_CONCURRENT_MARK
 142 static float concurrent_evacuation_threshold = 0.0f;
 143 static gboolean want_evacuation = FALSE;
 144 #endif
 145
 146 static gboolean lazy_sweep = TRUE;
 147 static gboolean have_swept;
 148
 149 #ifdef SGEN_HAVE_CONCURRENT_MARK
 150 static gboolean concurrent_mark;
 151 #endif
 152
 153 #define BLOCK_IS_TAGGED_HAS_REFERENCES(bl)      SGEN_POINTER_IS_TAGGED_1 ((bl))
 154 #define BLOCK_TAG_HAS_REFERENCES(bl)            SGEN_POINTER_TAG_1 ((bl))
 155 #define BLOCK_UNTAG_HAS_REFERENCES(bl)          SGEN_POINTER_UNTAG_1 ((bl))
 156
 157 #define BLOCK_TAG(bl)   ((bl)->has_references ? BLOCK_TAG_HAS_REFERENCES ((bl)) : (bl))
 158
 159 /* all allocated blocks in the system */
 160 static SgenPointerQueue allocated_blocks;
 161
 162 /* non-allocated block free-list */
 163 static void *empty_blocks = NULL;
 164 static size_t num_empty_blocks = 0;
 165
 166 #define FOREACH_BLOCK(bl)       { size_t __index; for (__index = 0; __index < allocated_blocks.next_slot; ++__index) { (bl) = BLOCK_UNTAG_HAS_REFERENCES (allocated_blocks.data [__index]);
 167 #define FOREACH_BLOCK_HAS_REFERENCES(bl,hr)     { size_t __index; for (__index = 0; __index < allocated_blocks.next_slot; ++__index) { (bl) = allocated_blocks.data [__index]; (hr) = BLOCK_IS_TAGGED_HAS_REFERENCES ((bl)); (bl) = BLOCK_UNTAG_HAS_REFERENCES ((bl));
 168 #define END_FOREACH_BLOCK       } }
 169 #define DELETE_BLOCK_IN_FOREACH()       (allocated_blocks.data [__index] = NULL)
 170
 171 static size_t num_major_sections = 0;
 172 /* one free block list for each block object size */
 173 static MSBlockInfo **free_block_lists [MS_BLOCK_TYPE_MAX];
 174
 175 static long long stat_major_blocks_alloced = 0;
 176 static long long stat_major_blocks_freed = 0;
 177 static long long stat_major_blocks_lazy_swept = 0;
 178 static long long stat_major_objects_evacuated = 0;
 179
 180 #if SIZEOF_VOID_P != 8
 181 static long long stat_major_blocks_freed_ideal = 0;
 182 static long long stat_major_blocks_freed_less_ideal = 0;
 183 static long long stat_major_blocks_freed_individual = 0;
 184 static long long stat_major_blocks_alloced_less_ideal = 0;
 185 #endif
 186
 187 #ifdef SGEN_COUNT_NUMBER_OF_MAJOR_OBJECTS_MARKED
 188 static long long num_major_objects_marked = 0;
 189 #define INC_NUM_MAJOR_OBJECTS_MARKED()  (++num_major_objects_marked)
 190 #else
 191 #define INC_NUM_MAJOR_OBJECTS_MARKED()
 192 #endif
 193
 194 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
 195 static mono_mutex_t scanned_objects_list_lock;
 196 static SgenPointerQueue scanned_objects_list;
 197
 198 static void
 199 add_scanned_object (void *ptr)
 200 {
 201         if (!binary_protocol_is_enabled ())
 202                 return;
 203
 204         mono_mutex_lock (&scanned_objects_list_lock);
 205         sgen_pointer_queue_add (&scanned_objects_list, ptr);
 206         mono_mutex_unlock (&scanned_objects_list_lock);
 207 }
 208 #endif
 209
 210 static void
 211 sweep_block (MSBlockInfo *block, gboolean during_major_collection);
 212
 213 static int
 214 ms_find_block_obj_size_index (size_t size)
 215 {
 216         int i;
 217         SGEN_ASSERT (9, size <= SGEN_MAX_SMALL_OBJ_SIZE, "size %d is bigger than max small object size %d", size, SGEN_MAX_SMALL_OBJ_SIZE);
 218         for (i = 0; i < num_block_obj_sizes; ++i)
 219                 if (block_obj_sizes [i] >= size)
 220                         return i;
 221         g_error ("no object of size %d\n", size);
 222 }
 223
 224 #define FREE_BLOCKS_FROM(lists,p,r)     (lists [((p) ? MS_BLOCK_FLAG_PINNED : 0) | ((r) ? MS_BLOCK_FLAG_REFS : 0)])
 225 #define FREE_BLOCKS(p,r)                (FREE_BLOCKS_FROM (free_block_lists, (p), (r)))
 226
 227 #define MS_BLOCK_OBJ_SIZE_INDEX(s)                              \
 228         (((s)+7)>>3 < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES ?      \
 229          fast_block_obj_size_indexes [((s)+7)>>3] :             \
 230          ms_find_block_obj_size_index ((s)))
 231
 232 static void*
 233 major_alloc_heap (mword nursery_size, mword nursery_align, int the_nursery_bits)
 234 {
 235         char *start;
 236         if (nursery_align)
 237                 start = sgen_alloc_os_memory_aligned (nursery_size, nursery_align, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE, "nursery");
 238         else
 239                 start = sgen_alloc_os_memory (nursery_size, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE, "nursery");
 240
 241         return start;
 242 }
 243
 244 static void
 245 update_heap_boundaries_for_block (MSBlockInfo *block)
 246 {
 247         sgen_update_heap_boundaries ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), (mword)MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE);
 248 }
 249
 250 static void*
 251 ms_get_empty_block (void)
 252 {
 253         char *p;
 254         int i;
 255         void *block, *empty, *next;
 256
 257  retry:
 258         if (!empty_blocks) {
 259                 /*
 260                  * We try allocating MS_BLOCK_ALLOC_NUM blocks first.  If that's
 261                  * unsuccessful, we halve the number of blocks and try again, until we're at
 262                  * 1.  If that doesn't work, either, we assert.
 263                  */
 264                 int alloc_num = MS_BLOCK_ALLOC_NUM;
 265                 for (;;) {
 266                         p = sgen_alloc_os_memory_aligned (MS_BLOCK_SIZE * alloc_num, MS_BLOCK_SIZE, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE,
 267                                         alloc_num == 1 ? "major heap section" : NULL);
 268                         if (p)
 269                                 break;
 270                         alloc_num >>= 1;
 271                 }
 272
 273                 for (i = 0; i < alloc_num; ++i) {
 274                         block = p;
 275                         /*
 276                          * We do the free list update one after the
 277                          * other so that other threads can use the new
 278                          * blocks as quickly as possible.
 279                          */
 280                         do {
 281                                 empty = empty_blocks;
 282                                 *(void**)block = empty;
 283                         } while (SGEN_CAS_PTR ((gpointer*)&empty_blocks, block, empty) != empty);
 284                         p += MS_BLOCK_SIZE;
 285                 }
 286
 287                 SGEN_ATOMIC_ADD_P (num_empty_blocks, alloc_num);
 288
 289                 stat_major_blocks_alloced += alloc_num;
 290 #if SIZEOF_VOID_P != 8
 291                 if (alloc_num != MS_BLOCK_ALLOC_NUM)
 292                         stat_major_blocks_alloced_less_ideal += alloc_num;
 293 #endif
 294         }
 295
 296         do {
 297                 empty = empty_blocks;
 298                 if (!empty)
 299                         goto retry;
 300                 block = empty;
 301                 next = *(void**)block;
 302         } while (SGEN_CAS_PTR (&empty_blocks, next, empty) != empty);
 303
 304         SGEN_ATOMIC_ADD_P (num_empty_blocks, -1);
 305
 306         *(void**)block = NULL;
 307
 308         g_assert (!((mword)block & (MS_BLOCK_SIZE - 1)));
 309
 310         return block;
 311 }
 312
 313 static void
 314 ms_free_block (void *block)
 315 {
 316         void *empty;
 317
 318         sgen_memgov_release_space (MS_BLOCK_SIZE, SPACE_MAJOR);
 319         memset (block, 0, MS_BLOCK_SIZE);
 320
 321         do {
 322                 empty = empty_blocks;
 323                 *(void**)block = empty;
 324         } while (SGEN_CAS_PTR (&empty_blocks, block, empty) != empty);
 325
 326         SGEN_ATOMIC_ADD_P (num_empty_blocks, 1);
 327 }
 328
 329 //#define MARKSWEEP_CONSISTENCY_CHECK
 330
 331 #ifdef MARKSWEEP_CONSISTENCY_CHECK
 332 static void
 333 check_block_free_list (MSBlockInfo *block, int size, gboolean pinned)
 334 {
 335         MSBlockInfo *b;
 336
 337         for (; block; block = block->next_free) {
 338                 g_assert (block->obj_size == size);
 339                 g_assert ((pinned && block->pinned) || (!pinned && !block->pinned));
 340
 341                 /* blocks in the free lists must have at least
 342                    one free slot */
 343                 if (block->swept)
 344                         g_assert (block->free_list);
 345
 346                 /* the block must be in the allocated_blocks array */
 347                 g_assert (sgen_pointer_queue_find (&allocated_blocks, BLOCK_TAG (block)) != (size_t)-1);
 348         }
 349 }
 350
 351 static void
 352 check_empty_blocks (void)
 353 {
 354         void *p;
 355         size_t i = 0;
 356         for (p = empty_blocks; p; p = *(void**)p)
 357                 ++i;
 358         g_assert (i == num_empty_blocks);
 359 }
 360
 361 static void
 362 consistency_check (void)
 363 {
 364         MSBlockInfo *block;
 365         int i;
 366
 367         /* check all blocks */
 368         FOREACH_BLOCK (block) {
 369                 int count = MS_BLOCK_FREE / block->obj_size;
 370                 int num_free = 0;
 371                 void **free;
 372
 373                 /* check block header */
 374                 g_assert (((MSBlockHeader*)block->block)->info == block);
 375
 376                 /* count number of free slots */
 377                 for (i = 0; i < count; ++i) {
 378                         void **obj = (void**) MS_BLOCK_OBJ (block, i);
 379                         if (!MS_OBJ_ALLOCED (obj, block))
 380                                 ++num_free;
 381                 }
 382
 383                 /* check free list */
 384                 for (free = block->free_list; free; free = (void**)*free) {
 385                         g_assert (MS_BLOCK_FOR_OBJ (free) == block);
 386                         --num_free;
 387                 }
 388                 g_assert (num_free == 0);
 389
 390                 /* check all mark words are zero */
 391                 if (block->swept) {
 392                         for (i = 0; i < MS_NUM_MARK_WORDS; ++i)
 393                                 g_assert (block->mark_words [i] == 0);
 394                 }
 395         } END_FOREACH_BLOCK;
 396
 397         /* check free blocks */
 398         for (i = 0; i < num_block_obj_sizes; ++i) {
 399                 int j;
 400                 for (j = 0; j < MS_BLOCK_TYPE_MAX; ++j)
 401                         check_block_free_list (free_block_lists [j][i], block_obj_sizes [i], j & MS_BLOCK_FLAG_PINNED);
 402         }
 403
 404         check_empty_blocks ();
 405 }
 406 #endif
 407
 408 static gboolean
 409 ms_alloc_block (int size_index, gboolean pinned, gboolean has_references)
 410 {
 411         int size = block_obj_sizes [size_index];
 412         int count = MS_BLOCK_FREE / size;
 413         MSBlockInfo *info;
 414         MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, has_references);
 415         char *obj_start;
 416         int i;
 417
 418         if (!sgen_memgov_try_alloc_space (MS_BLOCK_SIZE, SPACE_MAJOR))
 419                 return FALSE;
 420
 421         info = (MSBlockInfo*)ms_get_empty_block ();
 422
 423         SGEN_ASSERT (9, count >= 2, "block with %d objects, it must hold at least 2", count);
 424
 425         info->obj_size = size;
 426         info->obj_size_index = size_index;
 427         info->pinned = pinned;
 428         info->has_references = has_references;
 429         info->has_pinned = pinned;
 430         /*
 431          * Blocks that are to-space are not evacuated from.  During an major collection
 432          * blocks are allocated for two reasons: evacuating objects from the nursery and
 433          * evacuating them from major blocks marked for evacuation.  In both cases we don't
 434          * want further evacuation.
 435          */
 436         info->is_to_space = (sgen_get_current_collection_generation () == GENERATION_OLD);
 437         info->swept = 1;
 438 #ifdef SGEN_HAVE_CONCURRENT_MARK
 439         info->cardtable_mod_union = NULL;
 440 #endif
 441
 442         update_heap_boundaries_for_block (info);
 443
 444         /* build free list */
 445         obj_start = MS_BLOCK_FOR_BLOCK_INFO (info) + MS_BLOCK_SKIP;
 446         info->free_list = (void**)obj_start;
 447         /* we're skipping the last one - it must be nulled */
 448         for (i = 0; i < count - 1; ++i) {
 449                 char *next_obj_start = obj_start + size;
 450                 *(void**)obj_start = next_obj_start;
 451                 obj_start = next_obj_start;
 452         }
 453         /* the last one */
 454         *(void**)obj_start = NULL;
 455
 456         info->next_free = free_blocks [size_index];
 457         free_blocks [size_index] = info;
 458
 459         sgen_pointer_queue_add (&allocated_blocks, BLOCK_TAG (info));
 460
 461         ++num_major_sections;
 462         return TRUE;
 463 }
 464
 465 static gboolean
 466 obj_is_from_pinned_alloc (char *ptr)
 467 {
 468         MSBlockInfo *block;
 469
 470         FOREACH_BLOCK (block) {
 471                 if (ptr >= MS_BLOCK_FOR_BLOCK_INFO (block) && ptr <= MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE)
 472                         return block->pinned;
 473         } END_FOREACH_BLOCK;
 474         return FALSE;
 475 }
 476
 477 static void*
 478 unlink_slot_from_free_list_uncontested (MSBlockInfo **free_blocks, int size_index)
 479 {
 480         MSBlockInfo *block;
 481         void *obj;
 482
 483         block = free_blocks [size_index];
 484         SGEN_ASSERT (9, block, "no free block to unlink from free_blocks %p size_index %d", free_blocks, size_index);
 485
 486         if (G_UNLIKELY (!block->swept)) {
 487                 stat_major_blocks_lazy_swept ++;
 488                 sweep_block (block, FALSE);
 489         }
 490
 491         obj = block->free_list;
 492         SGEN_ASSERT (9, obj, "block %p in free list had no available object to alloc from", block);
 493
 494         block->free_list = *(void**)obj;
 495         if (!block->free_list) {
 496                 free_blocks [size_index] = block->next_free;
 497                 block->next_free = NULL;
 498         }
 499
 500         return obj;
 501 }
 502
 503 static void*
 504 alloc_obj (MonoVTable *vtable, size_t size, gboolean pinned, gboolean has_references)
 505 {
 506         int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
 507         MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, has_references);
 508         void *obj;
 509
 510         if (!free_blocks [size_index]) {
 511                 if (G_UNLIKELY (!ms_alloc_block (size_index, pinned, has_references)))
 512                         return NULL;
 513         }
 514
 515         obj = unlink_slot_from_free_list_uncontested (free_blocks, size_index);
 516
 517         *(MonoVTable**)obj = vtable;
 518
 519         return obj;
 520 }
 521
 522 static void*
 523 major_alloc_object (MonoVTable *vtable, size_t size, gboolean has_references)
 524 {
 525         return alloc_obj (vtable, size, FALSE, has_references);
 526 }
 527
 528 /*
 529  * We're not freeing the block if it's empty.  We leave that work for
 530  * the next major collection.
 531  *
 532  * This is just called from the domain clearing code, which runs in a
 533  * single thread and has the GC lock, so we don't need an extra lock.
 534  */
 535 static void
 536 free_object (char *obj, size_t size, gboolean pinned)
 537 {
 538         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
 539         int word, bit;
 540
 541         if (!block->swept)
 542                 sweep_block (block, FALSE);
 543         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);
 544         SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p is already free", obj);
 545         MS_CALC_MARK_BIT (word, bit, obj);
 546         SGEN_ASSERT (9, !MS_MARK_BIT (block, word, bit), "object %p has mark bit set");
 547         if (!block->free_list) {
 548                 MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, block->has_references);
 549                 int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
 550                 SGEN_ASSERT (9, !block->next_free, "block %p doesn't have a free-list of object but belongs to a free-list of blocks");
 551                 block->next_free = free_blocks [size_index];
 552                 free_blocks [size_index] = block;
 553         }
 554         memset (obj, 0, size);
 555         *(void**)obj = block->free_list;
 556         block->free_list = (void**)obj;
 557 }
 558
 559 static void
 560 major_free_non_pinned_object (char *obj, size_t size)
 561 {
 562         free_object (obj, size, FALSE);
 563 }
 564
 565 /* size is a multiple of SGEN_ALLOC_ALIGN */
 566 static void*
 567 major_alloc_small_pinned_obj (MonoVTable *vtable, size_t size, gboolean has_references)
 568 {
 569         void *res;
 570
 571         res = alloc_obj (vtable, size, TRUE, has_references);
 572          /*If we failed to alloc memory, we better try releasing memory
 573           *as pinned alloc is requested by the runtime.
 574           */
 575          if (!res) {
 576                 sgen_perform_collection (0, GENERATION_OLD, "pinned alloc failure", TRUE);
 577                 res = alloc_obj (vtable, size, TRUE, has_references);
 578          }
 579          return res;
 580 }
 581
 582 static void
 583 free_pinned_object (char *obj, size_t size)
 584 {
 585         free_object (obj, size, TRUE);
 586 }
 587
 588 /*
 589  * size is already rounded up and we hold the GC lock.
 590  */
 591 static void*
 592 major_alloc_degraded (MonoVTable *vtable, size_t size)
 593 {
 594         void *obj;
 595         size_t old_num_sections;
 596
 597         old_num_sections = num_major_sections;
 598
 599         obj = alloc_obj (vtable, size, FALSE, SGEN_VTABLE_HAS_REFERENCES (vtable));
 600         if (G_LIKELY (obj)) {
 601                 HEAVY_STAT (++stat_objects_alloced_degraded);
 602                 HEAVY_STAT (stat_bytes_alloced_degraded += size);
 603                 g_assert (num_major_sections >= old_num_sections);
 604                 sgen_register_major_sections_alloced (num_major_sections - old_num_sections);
 605         }
 606         return obj;
 607 }
 608
 609 /*
 610  * obj is some object.  If it's not in the major heap (i.e. if it's in
 611  * the nursery or LOS), return FALSE.  Otherwise return whether it's
 612  * been marked or copied.
 613  */
 614 static gboolean
 615 major_is_object_live (char *obj)
 616 {
 617         MSBlockInfo *block;
 618         int word, bit;
 619         mword objsize;
 620
 621         if (sgen_ptr_in_nursery (obj))
 622                 return FALSE;
 623
 624         objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
 625
 626         /* LOS */
 627         if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
 628                 return FALSE;
 629
 630         /* now we know it's in a major block */
 631         block = MS_BLOCK_FOR_OBJ (obj);
 632         SGEN_ASSERT (9, !block->pinned, "block %p is pinned, BTW why is this bad?");
 633         MS_CALC_MARK_BIT (word, bit, obj);
 634         return MS_MARK_BIT (block, word, bit) ? TRUE : FALSE;
 635 }
 636
 637 static gboolean
 638 major_ptr_is_in_non_pinned_space (char *ptr, char **start)
 639 {
 640         MSBlockInfo *block;
 641
 642         FOREACH_BLOCK (block) {
 643                 if (ptr >= MS_BLOCK_FOR_BLOCK_INFO (block) && ptr <= MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) {
 644                         int count = MS_BLOCK_FREE / block->obj_size;
 645                         int i;
 646
 647                         *start = NULL;
 648                         for (i = 0; i <= count; ++i) {
 649                                 if (ptr >= MS_BLOCK_OBJ (block, i) && ptr < MS_BLOCK_OBJ (block, i + 1)) {
 650                                         *start = MS_BLOCK_OBJ (block, i);
 651                                         break;
 652                                 }
 653                         }
 654                         return !block->pinned;
 655                 }
 656         } END_FOREACH_BLOCK;
 657         return FALSE;
 658 }
 659
 660 static void
 661 major_iterate_objects (IterateObjectsFlags flags, IterateObjectCallbackFunc callback, void *data)
 662 {
 663         gboolean sweep = flags & ITERATE_OBJECTS_SWEEP;
 664         gboolean non_pinned = flags & ITERATE_OBJECTS_NON_PINNED;
 665         gboolean pinned = flags & ITERATE_OBJECTS_PINNED;
 666         MSBlockInfo *block;
 667
 668         FOREACH_BLOCK (block) {
 669                 int count = MS_BLOCK_FREE / block->obj_size;
 670                 int i;
 671
 672                 if (block->pinned && !pinned)
 673                         continue;
 674                 if (!block->pinned && !non_pinned)
 675                         continue;
 676                 if (sweep && lazy_sweep) {
 677                         sweep_block (block, FALSE);
 678                         SGEN_ASSERT (0, block->swept, "Block must be swept after sweeping");
 679                 }
 680
 681                 for (i = 0; i < count; ++i) {
 682                         void **obj = (void**) MS_BLOCK_OBJ (block, i);
 683                         if (!block->swept) {
 684                                 int word, bit;
 685                                 MS_CALC_MARK_BIT (word, bit, obj);
 686                                 if (!MS_MARK_BIT (block, word, bit))
 687                                         continue;
 688                         }
 689                         if (MS_OBJ_ALLOCED (obj, block))
 690                                 callback ((char*)obj, block->obj_size, data);
 691                 }
 692         } END_FOREACH_BLOCK;
 693 }
 694
 695 static gboolean
 696 major_is_valid_object (char *object)
 697 {
 698         MSBlockInfo *block;
 699
 700         FOREACH_BLOCK (block) {
 701                 int idx;
 702                 char *obj;
 703
 704                 if ((MS_BLOCK_FOR_BLOCK_INFO (block) > object) || ((MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) <= object))
 705                         continue;
 706
 707                 idx = MS_BLOCK_OBJ_INDEX (object, block);
 708                 obj = (char*)MS_BLOCK_OBJ (block, idx);
 709                 if (obj != object)
 710                         return FALSE;
 711                 return MS_OBJ_ALLOCED (obj, block);
 712         } END_FOREACH_BLOCK;
 713
 714         return FALSE;
 715 }
 716
 717
 718 static MonoVTable*
 719 major_describe_pointer (char *ptr)
 720 {
 721         MSBlockInfo *block;
 722
 723         FOREACH_BLOCK (block) {
 724                 int idx;
 725                 char *obj;
 726                 gboolean live;
 727                 MonoVTable *vtable;
 728                 int w, b;
 729                 gboolean marked;
 730
 731                 if ((MS_BLOCK_FOR_BLOCK_INFO (block) > ptr) || ((MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) <= ptr))
 732                         continue;
 733
 734                 SGEN_LOG (0, "major-ptr (block %p sz %d pin %d ref %d)\n",
 735                         MS_BLOCK_FOR_BLOCK_INFO (block), block->obj_size, block->pinned, block->has_references);
 736
 737                 idx = MS_BLOCK_OBJ_INDEX (ptr, block);
 738                 obj = (char*)MS_BLOCK_OBJ (block, idx);
 739                 live = MS_OBJ_ALLOCED (obj, block);
 740                 vtable = live ? (MonoVTable*)SGEN_LOAD_VTABLE (obj) : NULL;
 741
 742                 MS_CALC_MARK_BIT (w, b, obj);
 743                 marked = MS_MARK_BIT (block, w, b);
 744
 745                 if (obj == ptr) {
 746                         SGEN_LOG (0, "\t(");
 747                         if (live)
 748                                 SGEN_LOG (0, "object");
 749                         else
 750                                 SGEN_LOG (0, "dead-object");
 751                 } else {
 752                         if (live)
 753                                 SGEN_LOG (0, "interior-ptr offset %td", ptr - obj);
 754                         else
 755                                 SGEN_LOG (0, "dead-interior-ptr offset %td", ptr - obj);
 756                 }
 757
 758                 SGEN_LOG (0, " marked %d)\n", marked ? 1 : 0);
 759
 760                 return vtable;
 761         } END_FOREACH_BLOCK;
 762
 763         return NULL;
 764 }
 765
 766 static void
 767 major_check_scan_starts (void)
 768 {
 769 }
 770
 771 static void
 772 major_dump_heap (FILE *heap_dump_file)
 773 {
 774         MSBlockInfo *block;
 775         int *slots_available = alloca (sizeof (int) * num_block_obj_sizes);
 776         int *slots_used = alloca (sizeof (int) * num_block_obj_sizes);
 777         int i;
 778
 779         for (i = 0; i < num_block_obj_sizes; ++i)
 780                 slots_available [i] = slots_used [i] = 0;
 781
 782         FOREACH_BLOCK (block) {
 783                 int index = ms_find_block_obj_size_index (block->obj_size);
 784                 int count = MS_BLOCK_FREE / block->obj_size;
 785
 786                 slots_available [index] += count;
 787                 for (i = 0; i < count; ++i) {
 788                         if (MS_OBJ_ALLOCED (MS_BLOCK_OBJ (block, i), block))
 789                                 ++slots_used [index];
 790                 }
 791         } END_FOREACH_BLOCK;
 792
 793         fprintf (heap_dump_file, "<occupancies>\n");
 794         for (i = 0; i < num_block_obj_sizes; ++i) {
 795                 fprintf (heap_dump_file, "<occupancy size=\"%d\" available=\"%d\" used=\"%d\" />\n",
 796                                 block_obj_sizes [i], slots_available [i], slots_used [i]);
 797         }
 798         fprintf (heap_dump_file, "</occupancies>\n");
 799
 800         FOREACH_BLOCK (block) {
 801                 int count = MS_BLOCK_FREE / block->obj_size;
 802                 int i;
 803                 int start = -1;
 804
 805                 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%zu\">\n", "old", (size_t)MS_BLOCK_FREE);
 806
 807                 for (i = 0; i <= count; ++i) {
 808                         if ((i < count) && MS_OBJ_ALLOCED (MS_BLOCK_OBJ (block, i), block)) {
 809                                 if (start < 0)
 810                                         start = i;
 811                         } else {
 812                                 if (start >= 0) {
 813                                         sgen_dump_occupied (MS_BLOCK_OBJ (block, start), MS_BLOCK_OBJ (block, i), MS_BLOCK_FOR_BLOCK_INFO (block));
 814                                         start = -1;
 815                                 }
 816                         }
 817                 }
 818
 819                 fprintf (heap_dump_file, "</section>\n");
 820         } END_FOREACH_BLOCK;
 821 }
 822
 823 #define LOAD_VTABLE     SGEN_LOAD_VTABLE
 824
 825 #define MS_MARK_OBJECT_AND_ENQUEUE_CHECKED(obj,desc,block,queue) do {   \
 826                 int __word, __bit;                                      \
 827                 SGEN_ASSERT (0, sgen_get_current_collection_generation () == GENERATION_OLD, "Can't majorly enqueue objects when doing minor collection"); \
 828                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 829                 if (MS_OBJ_ALLOCED ((obj), (block))) { \
 830                         if ((block)->has_references) {                  \
 831                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 832                         } else {                                        \
 833                                 MS_SET_MARK_BIT ((block), __word, __bit); \
 834                                 binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 835                         }                                               \
 836                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 837                 }                                                       \
 838         } while (0)
 839 #define MS_MARK_OBJECT_AND_ENQUEUE(obj,desc,block,queue) do {           \
 840                 int __word, __bit;                                      \
 841                 SGEN_ASSERT (0, sgen_get_current_collection_generation () == GENERATION_OLD, "Can't majorly enqueue objects when doing minor collection"); \
 842                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 843                 SGEN_ASSERT (9, MS_OBJ_ALLOCED ((obj), (block)), "object %p not allocated", obj);       \
 844                 {               \
 845                         if ((block)->has_references) {                  \
 846                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 847                         } else {                                        \
 848                                 MS_SET_MARK_BIT ((block), __word, __bit); \
 849                                 binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 850                         }                                               \
 851                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 852                 }                                                       \
 853         } while (0)
 854
 855 static void
 856 pin_major_object (char *obj, SgenGrayQueue *queue)
 857 {
 858         MSBlockInfo *block;
 859
 860 #ifdef SGEN_HAVE_CONCURRENT_MARK
 861         if (concurrent_mark)
 862                 g_assert_not_reached ();
 863 #endif
 864
 865         block = MS_BLOCK_FOR_OBJ (obj);
 866         block->has_pinned = TRUE;
 867         MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 868 }
 869
 870 #include "sgen-major-copy-object.h"
 871
 872 #ifdef SGEN_HAVE_CONCURRENT_MARK
 873 static void
 874 major_copy_or_mark_object_concurrent (void **ptr, void *obj, SgenGrayQueue *queue)
 875 {
 876         SGEN_ASSERT (9, sgen_concurrent_collection_in_progress (), "Why are we scanning concurrently when there's no concurrent collection on?");
 877         SGEN_ASSERT (9, !sgen_workers_are_working () || sgen_is_worker_thread (mono_native_thread_id_get ()), "We must not scan from two threads at the same time!");
 878
 879         g_assert (!SGEN_OBJECT_IS_FORWARDED (obj));
 880
 881         if (!sgen_ptr_in_nursery (obj)) {
 882                 mword objsize;
 883
 884                 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
 885
 886                 if (objsize <= SGEN_MAX_SMALL_OBJ_SIZE) {
 887                         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
 888                         MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 889                 } else {
 890                         if (sgen_los_object_is_pinned (obj))
 891                                 return;
 892
 893 #ifdef ENABLE_DTRACE
 894                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
 895                                 MonoVTable *vt = (MonoVTable*)SGEN_LOAD_VTABLE (obj);
 896                                 MONO_GC_OBJ_PINNED ((mword)obj, sgen_safe_object_get_size (obj), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
 897                         }
 898 #endif
 899
 900                         sgen_los_pin_object (obj);
 901                         if (SGEN_OBJECT_HAS_REFERENCES (obj))
 902                                 GRAY_OBJECT_ENQUEUE (queue, obj, sgen_obj_get_descriptor (obj));
 903                         INC_NUM_MAJOR_OBJECTS_MARKED ();
 904                 }
 905         }
 906 }
 907 #endif
 908
 909 static void
 910 major_copy_or_mark_object (void **ptr, void *obj, SgenGrayQueue *queue)
 911 {
 912         MSBlockInfo *block;
 913
 914         HEAVY_STAT (++stat_copy_object_called_major);
 915
 916         SGEN_ASSERT (9, !sgen_concurrent_collection_in_progress (), "Why are we scanning non-concurrently when there's a concurrent collection on?");
 917
 918         SGEN_ASSERT (9, obj, "null object from pointer %p", ptr);
 919         SGEN_ASSERT (9, current_collection_generation == GENERATION_OLD, "old gen parallel allocator called from a %d collection", current_collection_generation);
 920
 921         if (sgen_ptr_in_nursery (obj)) {
 922                 int word, bit;
 923                 char *forwarded, *old_obj;
 924
 925                 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 926                         SGEN_UPDATE_REFERENCE (ptr, forwarded);
 927                         return;
 928                 }
 929                 if (SGEN_OBJECT_IS_PINNED (obj))
 930                         return;
 931
 932                 /* An object in the nursery To Space has already been copied and grayed. Nothing to do. */
 933                 if (sgen_nursery_is_to_space (obj))
 934                         return;
 935
 936                 HEAVY_STAT (++stat_objects_copied_major);
 937
 938         do_copy_object:
 939                 old_obj = obj;
 940                 obj = copy_object_no_checks (obj, queue);
 941                 if (G_UNLIKELY (old_obj == obj)) {
 942                         /*If we fail to evacuate an object we just stop doing it for a given block size as all other will surely fail too.*/
 943                         if (!sgen_ptr_in_nursery (obj)) {
 944                                 int size_index;
 945                                 block = MS_BLOCK_FOR_OBJ (obj);
 946                                 size_index = block->obj_size_index;
 947                                 evacuate_block_obj_sizes [size_index] = FALSE;
 948                                 MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 949                         }
 950                         return;
 951                 }
 952                 SGEN_UPDATE_REFERENCE (ptr, obj);
 953
 954                 /*
 955                  * FIXME: See comment for copy_object_no_checks().  If
 956                  * we have that, we can let the allocation function
 957                  * give us the block info, too, and we won't have to
 958                  * re-fetch it.
 959                  *
 960                  * FIXME (2): We should rework this to avoid all those nursery checks.
 961                  */
 962                 /*
 963                  * For the split nursery allocator the object might
 964                  * still be in the nursery despite having being
 965                  * promoted, in which case we can't mark it.
 966                  */
 967                 if (!sgen_ptr_in_nursery (obj)) {
 968                         block = MS_BLOCK_FOR_OBJ (obj);
 969                         MS_CALC_MARK_BIT (word, bit, obj);
 970                         SGEN_ASSERT (9, !MS_MARK_BIT (block, word, bit), "object %p already marked", obj);
 971                         if (!SGEN_VTABLE_HAS_REFERENCES (LOAD_VTABLE (obj))) {
 972                                 MS_SET_MARK_BIT (block, word, bit);
 973                                 binary_protocol_mark (obj, (gpointer)LOAD_VTABLE (obj), sgen_safe_object_get_size ((MonoObject*)obj));
 974                         }
 975                 }
 976         } else {
 977                 char *forwarded;
 978                 mword objsize;
 979
 980                 /*
 981                  * If we have don't have a fixed heap we cannot know
 982                  * whether an object is in the LOS or in the small
 983                  * object major heap without checking its size.  To do
 984                  * that, however, we need to know that we actually
 985                  * have a valid object, not a forwarding pointer, so
 986                  * we have to do this check first.
 987                  */
 988                 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 989                         SGEN_UPDATE_REFERENCE (ptr, forwarded);
 990                         return;
 991                 }
 992
 993                 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
 994
 995                 if (objsize <= SGEN_MAX_SMALL_OBJ_SIZE) {
 996                         int size_index;
 997                         gboolean evacuate;
 998
 999                         block = MS_BLOCK_FOR_OBJ (obj);
1000                         size_index = block->obj_size_index;
1001                         evacuate = evacuate_block_obj_sizes [size_index];
1002
1003                         if (evacuate && !block->has_pinned) {
1004                                 g_assert (!SGEN_OBJECT_IS_PINNED (obj));
1005                                 if (block->is_to_space)
1006                                         return;
1007                                 HEAVY_STAT (++stat_major_objects_evacuated);
1008                                 goto do_copy_object;
1009                         } else {
1010                                 MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
1011                         }
1012                 } else {
1013                         if (sgen_los_object_is_pinned (obj))
1014                                 return;
1015                         binary_protocol_pin (obj, (gpointer)SGEN_LOAD_VTABLE (obj), sgen_safe_object_get_size ((MonoObject*)obj));
1016
1017 #ifdef ENABLE_DTRACE
1018                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1019                                 MonoVTable *vt = (MonoVTable*)SGEN_LOAD_VTABLE (obj);
1020                                 MONO_GC_OBJ_PINNED ((mword)obj, sgen_safe_object_get_size (obj), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
1021                         }
1022 #endif
1023
1024                         if (SGEN_OBJECT_HAS_REFERENCES (obj))
1025                                 GRAY_OBJECT_ENQUEUE (queue, obj, sgen_obj_get_descriptor (obj));
1026                 }
1027         }
1028 }
1029
1030 static void
1031 major_copy_or_mark_object_canonical (void **ptr, SgenGrayQueue *queue)
1032 {
1033         major_copy_or_mark_object (ptr, *ptr, queue);
1034 }
1035
1036 #ifdef SGEN_HAVE_CONCURRENT_MARK
1037 static void
1038 major_copy_or_mark_object_concurrent_canonical (void **ptr, SgenGrayQueue *queue)
1039 {
1040         major_copy_or_mark_object_concurrent (ptr, *ptr, queue);
1041 }
1042 #endif
1043
1044 static long long
1045 major_get_and_reset_num_major_objects_marked (void)
1046 {
1047 #ifdef SGEN_COUNT_NUMBER_OF_MAJOR_OBJECTS_MARKED
1048         long long num = num_major_objects_marked;
1049         num_major_objects_marked = 0;
1050         return num;
1051 #else
1052         return 0;
1053 #endif
1054 }
1055
1056 #include "sgen-major-scan-object.h"
1057
1058 #ifdef SGEN_HAVE_CONCURRENT_MARK
1059 #define SCAN_FOR_CONCURRENT_MARK
1060 #include "sgen-major-scan-object.h"
1061 #undef SCAN_FOR_CONCURRENT_MARK
1062 #endif
1063
1064 #if !defined (FIXED_HEAP) && !defined (SGEN_PARALLEL_MARK)
1065 #define USE_PREFETCH_QUEUE
1066
1067 #ifdef HEAVY_STATISTICS
1068 static long long stat_optimized_copy_object_called;
1069 static long long stat_optimized_nursery;
1070 static long long stat_optimized_nursery_forwarded;
1071 static long long stat_optimized_nursery_pinned;
1072 static long long stat_optimized_major_mark;
1073 static long long stat_optimized_major_mark_small;
1074 static long long stat_optimized_major_mark_large;
1075 static long long stat_optimized_major_scan;
1076 static long long stat_optimized_major_scan_fast;
1077 static long long stat_optimized_major_scan_slow;
1078
1079 static long long stat_drain_prefetch_fills;
1080 static long long stat_drain_prefetch_fill_failures;
1081 static long long stat_drain_loops;
1082 #endif
1083
1084 /* Returns whether the object is still in the nursery. */
1085 static gboolean
1086 optimized_copy_or_mark_object (void **ptr, void *obj, SgenGrayQueue *queue)
1087 {
1088         HEAVY_STAT (++stat_optimized_copy_object_called);
1089
1090         SGEN_ASSERT (9, obj, "null object from pointer %p", ptr);
1091         SGEN_ASSERT (9, current_collection_generation == GENERATION_OLD, "old gen parallel allocator called from a %d collection", current_collection_generation);
1092
1093         if (sgen_ptr_in_nursery (obj)) {
1094                 mword vtable_word = *(mword*)obj;
1095                 char *forwarded, *old_obj;
1096
1097                 HEAVY_STAT (++stat_optimized_nursery);
1098
1099                 if (SGEN_VTABLE_IS_PINNED (vtable_word)) {
1100                         HEAVY_STAT (++stat_optimized_nursery_pinned);
1101                         return TRUE;
1102                 }
1103                 if ((forwarded = SGEN_VTABLE_IS_FORWARDED (vtable_word))) {
1104                         HEAVY_STAT (++stat_optimized_nursery_forwarded);
1105                         *ptr = forwarded;
1106                         return FALSE;
1107                 }
1108
1109                 old_obj = obj;
1110                 obj = copy_object_no_checks (obj, queue);
1111                 SGEN_ASSERT (0, old_obj != obj, "Cannot handle copy object failure.");
1112                 HEAVY_STAT (++stat_objects_copied_major);
1113                 *ptr = obj;
1114                 return FALSE;
1115         } else {
1116                 GRAY_OBJECT_ENQUEUE (queue, obj, 0);
1117         }
1118         return FALSE;
1119 }
1120
1121 static gboolean
1122 drain_gray_stack (ScanCopyContext ctx)
1123 {
1124         SgenGrayQueue *queue = ctx.queue;
1125
1126         SGEN_ASSERT (0, ctx.scan_func == major_scan_object, "Wrong scan function");
1127
1128 #ifdef USE_PREFETCH_QUEUE
1129         HEAVY_STAT (++stat_drain_prefetch_fills);
1130         if (!sgen_gray_object_fill_prefetch (queue)) {
1131                 HEAVY_STAT (++stat_drain_prefetch_fill_failures);
1132                 return TRUE;
1133         }
1134 #endif
1135
1136         for (;;) {
1137                 char *obj;
1138                 mword desc;
1139                 int type;
1140
1141                 HEAVY_STAT (++stat_drain_loops);
1142
1143 #ifdef USE_PREFETCH_QUEUE
1144                 sgen_gray_object_dequeue_fast (queue, &obj, &desc);
1145                 if (!obj) {
1146                         HEAVY_STAT (++stat_drain_prefetch_fills);
1147                         if (!sgen_gray_object_fill_prefetch (queue)) {
1148                                 HEAVY_STAT (++stat_drain_prefetch_fill_failures);
1149                                 return TRUE;
1150                         }
1151                         continue;
1152                 }
1153 #else
1154                 GRAY_OBJECT_DEQUEUE (queue, &obj, &desc);
1155                 if (!obj)
1156                         return TRUE;
1157 #endif
1158
1159                 desc = sgen_obj_get_descriptor_safe (obj);
1160                 type = desc & 7;
1161
1162                 HEAVY_STAT (++stat_optimized_major_mark);
1163
1164                 /* Mark object or, if already marked, don't process. */
1165                 if (!sgen_ptr_in_nursery (obj)) {
1166                         if (type == DESC_TYPE_SMALL_BITMAP || SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj)) <= SGEN_MAX_SMALL_OBJ_SIZE) {
1167                                 MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
1168                                 int __word, __bit;
1169
1170                                 HEAVY_STAT (++stat_optimized_major_mark_small);
1171
1172                                 MS_CALC_MARK_BIT (__word, __bit, (obj));
1173                                 if (MS_MARK_BIT ((block), __word, __bit))
1174                                         continue;
1175                                 MS_SET_MARK_BIT ((block), __word, __bit);
1176                         } else {
1177                                 HEAVY_STAT (++stat_optimized_major_mark_large);
1178
1179                                 if (sgen_los_object_is_pinned (obj))
1180                                         continue;
1181                                 sgen_los_pin_object (obj);
1182                         }
1183                 }
1184
1185                 HEAVY_STAT (++stat_optimized_major_scan);
1186
1187                 /* Now scan the object. */
1188 #ifdef HEAVY_STATISTICS
1189                 sgen_descriptor_count_scanned_object (desc);
1190 #endif
1191                 if (type == DESC_TYPE_SMALL_BITMAP) {
1192                         void **_objptr = (void**)(obj);
1193                         gsize _bmap = (desc) >> 16;
1194                         _objptr += OBJECT_HEADER_WORDS;
1195                         do {
1196                                 int _index = GNUC_BUILTIN_CTZ (_bmap);
1197                                 _objptr += _index;
1198                                 _bmap >>= (_index + 1);
1199
1200                                 void *__old = *(_objptr);
1201                                 if (__old) {
1202                                         gboolean still_in_nursery = optimized_copy_or_mark_object (_objptr, __old, queue);
1203                                         if (G_UNLIKELY (still_in_nursery && !sgen_ptr_in_nursery ((_objptr)))) {
1204                                                 void *__copy = *(_objptr);
1205                                                 sgen_add_to_global_remset ((_objptr), __copy);
1206                                         }
1207                                 }
1208
1209                                 _objptr ++;
1210                         } while (_bmap);
1211 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
1212                         add_scanned_object (obj);
1213                         ++stat_optimized_major_scan_slow;
1214 #endif
1215                 } else {
1216                         HEAVY_STAT (++stat_optimized_major_scan_fast);
1217                         major_scan_object_no_mark (obj, desc, queue);
1218                 }
1219         }
1220 }
1221 #endif
1222
1223 static void
1224 mark_pinned_objects_in_block (MSBlockInfo *block, SgenGrayQueue *queue)
1225 {
1226         void **entry, **end;
1227         int last_index = -1;
1228
1229         if (block->pin_queue_first_entry == block->pin_queue_last_entry)
1230                 return;
1231
1232         block->has_pinned = TRUE;
1233
1234         entry = sgen_pinning_get_entry (block->pin_queue_first_entry);
1235         end = sgen_pinning_get_entry (block->pin_queue_last_entry);
1236
1237         for (; entry < end; ++entry) {
1238                 int index = MS_BLOCK_OBJ_INDEX (*entry, block);
1239                 char *obj;
1240                 SGEN_ASSERT (9, index >= 0 && index < MS_BLOCK_FREE / block->obj_size, "invalid object %p index %d max-index %d", *entry, index, MS_BLOCK_FREE / block->obj_size);
1241                 if (index == last_index)
1242                         continue;
1243                 obj = MS_BLOCK_OBJ (block, index);
1244                 MS_MARK_OBJECT_AND_ENQUEUE_CHECKED (obj, sgen_obj_get_descriptor (obj), block, queue);
1245                 last_index = index;
1246         }
1247 }
1248
1249 static inline void
1250 sweep_block_for_size (MSBlockInfo *block, int count, int obj_size)
1251 {
1252         int obj_index;
1253
1254         for (obj_index = 0; obj_index < count; ++obj_index) {
1255                 int word, bit;
1256                 void *obj = MS_BLOCK_OBJ_FOR_SIZE (block, obj_index, obj_size);
1257
1258                 MS_CALC_MARK_BIT (word, bit, obj);
1259                 if (MS_MARK_BIT (block, word, bit)) {
1260                         SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p not allocated", obj);
1261                 } else {
1262                         /* an unmarked object */
1263                         if (MS_OBJ_ALLOCED (obj, block)) {
1264                                 /*
1265                                  * FIXME: Merge consecutive
1266                                  * slots for lower reporting
1267                                  * overhead.  Maybe memset
1268                                  * will also benefit?
1269                                  */
1270                                 binary_protocol_empty (obj, obj_size);
1271                                 MONO_GC_MAJOR_SWEPT ((mword)obj, obj_size);
1272                                 memset (obj, 0, obj_size);
1273                         }
1274                         *(void**)obj = block->free_list;
1275                         block->free_list = obj;
1276                 }
1277         }
1278 }
1279
1280 /*
1281  * sweep_block:
1282  *
1283  *   Traverse BLOCK, freeing and zeroing unused objects.
1284  */
1285 static void
1286 sweep_block (MSBlockInfo *block, gboolean during_major_collection)
1287 {
1288         int count;
1289         void *reversed = NULL;
1290
1291         if (!during_major_collection)
1292                 g_assert (!sgen_concurrent_collection_in_progress ());
1293
1294         if (block->swept)
1295                 return;
1296
1297         count = MS_BLOCK_FREE / block->obj_size;
1298
1299         block->free_list = NULL;
1300
1301         /* Use inline instances specialized to constant sizes, this allows the compiler to replace the memset calls with inline code */
1302         // FIXME: Add more sizes
1303         switch (block->obj_size) {
1304         case 16:
1305                 sweep_block_for_size (block, count, 16);
1306                 break;
1307         default:
1308                 sweep_block_for_size (block, count, block->obj_size);
1309                 break;
1310         }
1311
1312         /* reset mark bits */
1313         memset (block->mark_words, 0, sizeof (mword) * MS_NUM_MARK_WORDS);
1314
1315         /* Reverse free list so that it's in address order */
1316         reversed = NULL;
1317         while (block->free_list) {
1318                 void *next = *(void**)block->free_list;
1319                 *(void**)block->free_list = reversed;
1320                 reversed = block->free_list;
1321                 block->free_list = next;
1322         }
1323         block->free_list = reversed;
1324
1325         block->swept = 1;
1326 }
1327
1328 static inline int
1329 bitcount (mword d)
1330 {
1331         int count = 0;
1332
1333 #ifdef __GNUC__
1334         if (sizeof (mword) == sizeof (unsigned long))
1335                 count += __builtin_popcountl (d);
1336         else
1337                 count += __builtin_popcount (d);
1338 #else
1339         while (d) {
1340                 count ++;
1341                 d &= (d - 1);
1342         }
1343 #endif
1344         return count;
1345 }
1346
1347 static void
1348 ms_sweep (void)
1349 {
1350         int i;
1351         MSBlockInfo *block;
1352
1353         /* statistics for evacuation */
1354         int *slots_available = alloca (sizeof (int) * num_block_obj_sizes);
1355         int *slots_used = alloca (sizeof (int) * num_block_obj_sizes);
1356         int *num_blocks = alloca (sizeof (int) * num_block_obj_sizes);
1357
1358 #ifdef SGEN_HAVE_CONCURRENT_MARK
1359         mword total_evacuate_heap = 0;
1360         mword total_evacuate_saved = 0;
1361 #endif
1362
1363         for (i = 0; i < num_block_obj_sizes; ++i)
1364                 slots_available [i] = slots_used [i] = num_blocks [i] = 0;
1365
1366         /* clear all the free lists */
1367         for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i) {
1368                 MSBlockInfo **free_blocks = free_block_lists [i];
1369                 int j;
1370                 for (j = 0; j < num_block_obj_sizes; ++j)
1371                         free_blocks [j] = NULL;
1372         }
1373
1374         /* traverse all blocks, free and zero unmarked objects */
1375         FOREACH_BLOCK (block) {
1376                 int count;
1377                 gboolean have_live = FALSE;
1378                 gboolean has_pinned;
1379                 gboolean have_free = FALSE;
1380                 int obj_size_index;
1381                 int nused = 0;
1382
1383                 obj_size_index = block->obj_size_index;
1384
1385                 has_pinned = block->has_pinned;
1386                 block->has_pinned = block->pinned;
1387
1388                 block->is_to_space = FALSE;
1389                 block->swept = 0;
1390
1391                 count = MS_BLOCK_FREE / block->obj_size;
1392
1393 #ifdef SGEN_HAVE_CONCURRENT_MARK
1394                 if (block->cardtable_mod_union) {
1395                         sgen_free_internal_dynamic (block->cardtable_mod_union, CARDS_PER_BLOCK, INTERNAL_MEM_CARDTABLE_MOD_UNION);
1396                         block->cardtable_mod_union = NULL;
1397                 }
1398 #endif
1399
1400                 /* Count marked objects in the block */
1401                 for (i = 0; i < MS_NUM_MARK_WORDS; ++i) {
1402                         nused += bitcount (block->mark_words [i]);
1403                 }
1404                 if (nused) {
1405                         have_live = TRUE;
1406                 }
1407                 if (nused < count)
1408                         have_free = TRUE;
1409
1410                 if (!lazy_sweep)
1411                         sweep_block (block, TRUE);
1412
1413                 if (have_live) {
1414                         if (!has_pinned) {
1415                                 ++num_blocks [obj_size_index];
1416                                 slots_used [obj_size_index] += nused;
1417                                 slots_available [obj_size_index] += count;
1418                         }
1419
1420                         /*
1421                          * If there are free slots in the block, add
1422                          * the block to the corresponding free list.
1423                          */
1424                         if (have_free) {
1425                                 MSBlockInfo **free_blocks = FREE_BLOCKS (block->pinned, block->has_references);
1426                                 int index = MS_BLOCK_OBJ_SIZE_INDEX (block->obj_size);
1427                                 block->next_free = free_blocks [index];
1428                                 free_blocks [index] = block;
1429                         }
1430
1431                         update_heap_boundaries_for_block (block);
1432                 } else {
1433                         /*
1434                          * Blocks without live objects are removed from the
1435                          * block list and freed.
1436                          */
1437                         DELETE_BLOCK_IN_FOREACH ();
1438
1439                         binary_protocol_empty (MS_BLOCK_OBJ (block, 0), (char*)MS_BLOCK_OBJ (block, count) - (char*)MS_BLOCK_OBJ (block, 0));
1440                         ms_free_block (block);
1441
1442                         --num_major_sections;
1443                 }
1444         } END_FOREACH_BLOCK;
1445         sgen_pointer_queue_remove_nulls (&allocated_blocks);
1446
1447         for (i = 0; i < num_block_obj_sizes; ++i) {
1448                 float usage = (float)slots_used [i] / (float)slots_available [i];
1449                 if (num_blocks [i] > 5 && usage < evacuation_threshold) {
1450                         g_assert_not_reached ();
1451                         evacuate_block_obj_sizes [i] = TRUE;
1452                         /*
1453                         g_print ("slot size %d - %d of %d used\n",
1454                                         block_obj_sizes [i], slots_used [i], slots_available [i]);
1455                         */
1456                 } else {
1457                         evacuate_block_obj_sizes [i] = FALSE;
1458                 }
1459 #ifdef SGEN_HAVE_CONCURRENT_MARK
1460                 {
1461                         mword total_bytes = block_obj_sizes [i] * slots_available [i];
1462                         total_evacuate_heap += total_bytes;
1463                         if (evacuate_block_obj_sizes [i])
1464                                 total_evacuate_saved += total_bytes - block_obj_sizes [i] * slots_used [i];
1465                 }
1466 #endif
1467         }
1468
1469 #ifdef SGEN_HAVE_CONCURRENT_MARK
1470         want_evacuation = (float)total_evacuate_saved / (float)total_evacuate_heap > (1 - concurrent_evacuation_threshold);
1471 #endif
1472
1473         have_swept = TRUE;
1474 }
1475
1476 static void
1477 major_sweep (void)
1478 {
1479         ms_sweep ();
1480 }
1481
1482 static int count_pinned_ref;
1483 static int count_pinned_nonref;
1484 static int count_nonpinned_ref;
1485 static int count_nonpinned_nonref;
1486
1487 static void
1488 count_nonpinned_callback (char *obj, size_t size, void *data)
1489 {
1490         MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
1491
1492         if (vtable->klass->has_references)
1493                 ++count_nonpinned_ref;
1494         else
1495                 ++count_nonpinned_nonref;
1496 }
1497
1498 static void
1499 count_pinned_callback (char *obj, size_t size, void *data)
1500 {
1501         MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
1502
1503         if (vtable->klass->has_references)
1504                 ++count_pinned_ref;
1505         else
1506                 ++count_pinned_nonref;
1507 }
1508
1509 static G_GNUC_UNUSED void
1510 count_ref_nonref_objs (void)
1511 {
1512         int total;
1513
1514         count_pinned_ref = 0;
1515         count_pinned_nonref = 0;
1516         count_nonpinned_ref = 0;
1517         count_nonpinned_nonref = 0;
1518
1519         major_iterate_objects (ITERATE_OBJECTS_SWEEP_NON_PINNED, count_nonpinned_callback, NULL);
1520         major_iterate_objects (ITERATE_OBJECTS_SWEEP_PINNED, count_pinned_callback, NULL);
1521
1522         total = count_pinned_nonref + count_nonpinned_nonref + count_pinned_ref + count_nonpinned_ref;
1523
1524         g_print ("ref: %d pinned %d non-pinned   non-ref: %d pinned %d non-pinned  --  %.1f\n",
1525                         count_pinned_ref, count_nonpinned_ref,
1526                         count_pinned_nonref, count_nonpinned_nonref,
1527                         (count_pinned_nonref + count_nonpinned_nonref) * 100.0 / total);
1528 }
1529
1530 static int
1531 ms_calculate_block_obj_sizes (double factor, int *arr)
1532 {
1533         double target_size = sizeof (MonoObject);
1534         int num_sizes = 0;
1535         int last_size = 0;
1536
1537         do {
1538                 int target_count = (int)ceil (MS_BLOCK_FREE / target_size);
1539                 int size = MIN ((MS_BLOCK_FREE / target_count) & ~(SGEN_ALLOC_ALIGN - 1), SGEN_MAX_SMALL_OBJ_SIZE);
1540
1541                 if (size != last_size) {
1542                         if (arr)
1543                                 arr [num_sizes] = size;
1544                         ++num_sizes;
1545                         last_size = size;
1546                 }
1547
1548                 target_size *= factor;
1549         } while (last_size < SGEN_MAX_SMALL_OBJ_SIZE);
1550
1551         return num_sizes;
1552 }
1553
1554 /* only valid during minor collections */
1555 static mword old_num_major_sections;
1556
1557 static void
1558 major_start_nursery_collection (void)
1559 {
1560 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1561         consistency_check ();
1562 #endif
1563
1564         old_num_major_sections = num_major_sections;
1565 }
1566
1567 static void
1568 major_finish_nursery_collection (void)
1569 {
1570 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1571         consistency_check ();
1572 #endif
1573         sgen_register_major_sections_alloced (num_major_sections - old_num_major_sections);
1574 }
1575
1576 static void
1577 major_start_major_collection (void)
1578 {
1579         int i;
1580
1581         /* clear the free lists */
1582         for (i = 0; i < num_block_obj_sizes; ++i) {
1583                 if (!evacuate_block_obj_sizes [i])
1584                         continue;
1585
1586                 free_block_lists [0][i] = NULL;
1587                 free_block_lists [MS_BLOCK_FLAG_REFS][i] = NULL;
1588         }
1589
1590         // Sweep all unswept blocks
1591         if (lazy_sweep) {
1592                 MSBlockInfo *block;
1593
1594                 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, TRUE);
1595
1596                 FOREACH_BLOCK (block) {
1597                         sweep_block (block, TRUE);
1598                 } END_FOREACH_BLOCK;
1599
1600                 MONO_GC_SWEEP_END (GENERATION_OLD, TRUE);
1601         }
1602 }
1603
1604 static void
1605 major_finish_major_collection (ScannedObjectCounts *counts)
1606 {
1607 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
1608         if (binary_protocol_is_enabled ()) {
1609                 counts->num_scanned_objects = scanned_objects_list.next_slot;
1610
1611                 sgen_pointer_queue_sort_uniq (&scanned_objects_list);
1612                 counts->num_unique_scanned_objects = scanned_objects_list.next_slot;
1613
1614                 sgen_pointer_queue_clear (&scanned_objects_list);
1615         }
1616 #endif
1617 }
1618
1619 #if SIZEOF_VOID_P != 8
1620 static int
1621 compare_pointers (const void *va, const void *vb) {
1622         char *a = *(char**)va, *b = *(char**)vb;
1623         if (a < b)
1624                 return -1;
1625         if (a > b)
1626                 return 1;
1627         return 0;
1628 }
1629 #endif
1630
1631 static void
1632 major_have_computer_minor_collection_allowance (void)
1633 {
1634         size_t section_reserve = sgen_get_minor_collection_allowance () / MS_BLOCK_SIZE;
1635
1636         g_assert (have_swept);
1637
1638 #if SIZEOF_VOID_P != 8
1639         {
1640                 int i, num_empty_blocks_orig, num_blocks, arr_length;
1641                 void *block;
1642                 void **empty_block_arr;
1643                 void **rebuild_next;
1644
1645 #ifdef TARGET_WIN32
1646                 /*
1647                  * sgen_free_os_memory () asserts in mono_vfree () because windows doesn't like freeing the middle of
1648                  * a VirtualAlloc ()-ed block.
1649                  */
1650                 return;
1651 #endif
1652
1653                 if (num_empty_blocks <= section_reserve)
1654                         return;
1655                 SGEN_ASSERT (0, num_empty_blocks > 0, "section reserve can't be negative");
1656
1657                 num_empty_blocks_orig = num_empty_blocks;
1658                 empty_block_arr = (void**)sgen_alloc_internal_dynamic (sizeof (void*) * num_empty_blocks_orig,
1659                                 INTERNAL_MEM_MS_BLOCK_INFO_SORT, FALSE);
1660                 if (!empty_block_arr)
1661                         goto fallback;
1662
1663                 i = 0;
1664                 for (block = empty_blocks; block; block = *(void**)block)
1665                         empty_block_arr [i++] = block;
1666                 SGEN_ASSERT (0, i == num_empty_blocks, "empty block count wrong");
1667
1668                 sgen_qsort (empty_block_arr, num_empty_blocks, sizeof (void*), compare_pointers);
1669
1670                 /*
1671                  * We iterate over the free blocks, trying to find MS_BLOCK_ALLOC_NUM
1672                  * contiguous ones.  If we do, we free them.  If that's not enough to get to
1673                  * section_reserve, we halve the number of contiguous blocks we're looking
1674                  * for and have another go, until we're done with looking for pairs of
1675                  * blocks, at which point we give up and go to the fallback.
1676                  */
1677                 arr_length = num_empty_blocks_orig;
1678                 num_blocks = MS_BLOCK_ALLOC_NUM;
1679                 while (num_empty_blocks > section_reserve && num_blocks > 1) {
1680                         int first = -1;
1681                         int dest = 0;
1682
1683                         dest = 0;
1684                         for (i = 0; i < arr_length; ++i) {
1685                                 int d = dest;
1686                                 void *block = empty_block_arr [i];
1687                                 SGEN_ASSERT (0, block, "we're not shifting correctly");
1688                                 if (i != dest) {
1689                                         empty_block_arr [dest] = block;
1690                                         /*
1691                                          * This is not strictly necessary, but we're
1692                                          * cautious.
1693                                          */
1694                                         empty_block_arr [i] = NULL;
1695                                 }
1696                                 ++dest;
1697
1698                                 if (first < 0) {
1699                                         first = d;
1700                                         continue;
1701                                 }
1702
1703                                 SGEN_ASSERT (0, first >= 0 && d > first, "algorithm is wrong");
1704
1705                                 if ((char*)block != ((char*)empty_block_arr [d-1]) + MS_BLOCK_SIZE) {
1706                                         first = d;
1707                                         continue;
1708                                 }
1709
1710                                 if (d + 1 - first == num_blocks) {
1711                                         /*
1712                                          * We found num_blocks contiguous blocks.  Free them
1713                                          * and null their array entries.  As an optimization
1714                                          * we could, instead of nulling the entries, shift
1715                                          * the following entries over to the left, while
1716                                          * we're iterating.
1717                                          */
1718                                         int j;
1719                                         sgen_free_os_memory (empty_block_arr [first], MS_BLOCK_SIZE * num_blocks, SGEN_ALLOC_HEAP);
1720                                         for (j = first; j <= d; ++j)
1721                                                 empty_block_arr [j] = NULL;
1722                                         dest = first;
1723                                         first = -1;
1724
1725                                         num_empty_blocks -= num_blocks;
1726
1727                                         stat_major_blocks_freed += num_blocks;
1728                                         if (num_blocks == MS_BLOCK_ALLOC_NUM)
1729                                                 stat_major_blocks_freed_ideal += num_blocks;
1730                                         else
1731                                                 stat_major_blocks_freed_less_ideal += num_blocks;
1732
1733                                 }
1734                         }
1735
1736                         SGEN_ASSERT (0, dest <= i && dest <= arr_length, "array length is off");
1737                         arr_length = dest;
1738                         SGEN_ASSERT (0, arr_length == num_empty_blocks, "array length is off");
1739
1740                         num_blocks >>= 1;
1741                 }
1742
1743                 /* rebuild empty_blocks free list */
1744                 rebuild_next = (void**)&empty_blocks;
1745                 for (i = 0; i < arr_length; ++i) {
1746                         void *block = empty_block_arr [i];
1747                         SGEN_ASSERT (0, block, "we're missing blocks");
1748                         *rebuild_next = block;
1749                         rebuild_next = (void**)block;
1750                 }
1751                 *rebuild_next = NULL;
1752
1753                 /* free array */
1754                 sgen_free_internal_dynamic (empty_block_arr, sizeof (void*) * num_empty_blocks_orig, INTERNAL_MEM_MS_BLOCK_INFO_SORT);
1755         }
1756
1757         SGEN_ASSERT (0, num_empty_blocks >= 0, "we freed more blocks than we had in the first place?");
1758
1759  fallback:
1760         /*
1761          * This is our threshold.  If there's not more empty than used blocks, we won't
1762          * release uncontiguous blocks, in fear of fragmenting the address space.
1763          */
1764         if (num_empty_blocks <= num_major_sections)
1765                 return;
1766 #endif
1767
1768         while (num_empty_blocks > section_reserve) {
1769                 void *next = *(void**)empty_blocks;
1770                 sgen_free_os_memory (empty_blocks, MS_BLOCK_SIZE, SGEN_ALLOC_HEAP);
1771                 empty_blocks = next;
1772                 /*
1773                  * Needs not be atomic because this is running
1774                  * single-threaded.
1775                  */
1776                 --num_empty_blocks;
1777
1778                 ++stat_major_blocks_freed;
1779 #if SIZEOF_VOID_P != 8
1780                 ++stat_major_blocks_freed_individual;
1781 #endif
1782         }
1783 }
1784
1785 static void
1786 major_find_pin_queue_start_ends (SgenGrayQueue *queue)
1787 {
1788         MSBlockInfo *block;
1789
1790         FOREACH_BLOCK (block) {
1791                 sgen_find_optimized_pin_queue_area (MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SKIP, MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE,
1792                                 &block->pin_queue_first_entry, &block->pin_queue_last_entry);
1793         } END_FOREACH_BLOCK;
1794 }
1795
1796 static void
1797 major_pin_objects (SgenGrayQueue *queue)
1798 {
1799         MSBlockInfo *block;
1800
1801         FOREACH_BLOCK (block) {
1802                 mark_pinned_objects_in_block (block, queue);
1803         } END_FOREACH_BLOCK;
1804 }
1805
1806 static void
1807 major_init_to_space (void)
1808 {
1809 }
1810
1811 static void
1812 major_report_pinned_memory_usage (void)
1813 {
1814         g_assert_not_reached ();
1815 }
1816
1817 static gint64
1818 major_get_used_size (void)
1819 {
1820         gint64 size = 0;
1821         MSBlockInfo *block;
1822
1823         FOREACH_BLOCK (block) {
1824                 int count = MS_BLOCK_FREE / block->obj_size;
1825                 void **iter;
1826                 size += count * block->obj_size;
1827                 for (iter = block->free_list; iter; iter = (void**)*iter)
1828                         size -= block->obj_size;
1829         } END_FOREACH_BLOCK;
1830
1831         return size;
1832 }
1833
1834 static size_t
1835 get_num_major_sections (void)
1836 {
1837         return num_major_sections;
1838 }
1839
1840 static gboolean
1841 major_handle_gc_param (const char *opt)
1842 {
1843         /*
1844         if (g_str_has_prefix (opt, "evacuation-threshold=")) {
1845                 const char *arg = strchr (opt, '=') + 1;
1846                 int percentage = atoi (arg);
1847                 if (percentage < 0 || percentage > 100) {
1848                         fprintf (stderr, "evacuation-threshold must be an integer in the range 0-100.\n");
1849                         exit (1);
1850                 }
1851                 evacuation_threshold = (float)percentage / 100.0f;
1852                 return TRUE;
1853                 } else */
1854         if (!strcmp (opt, "lazy-sweep")) {
1855                 lazy_sweep = TRUE;
1856                 return TRUE;
1857         } else if (!strcmp (opt, "no-lazy-sweep")) {
1858                 lazy_sweep = FALSE;
1859                 return TRUE;
1860         }
1861
1862         return FALSE;
1863 }
1864
1865 static void
1866 major_print_gc_param_usage (void)
1867 {
1868         fprintf (stderr,
1869                         ""
1870                         "  evacuation-threshold=P (where P is a percentage, an integer in 0-100)\n"
1871                         "  (no-)lazy-sweep\n"
1872                         );
1873 }
1874
1875 static void
1876 major_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
1877 {
1878         MSBlockInfo *block;
1879         gboolean has_references;
1880
1881         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1882                 if (has_references)
1883                         callback ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE);
1884         } END_FOREACH_BLOCK;
1885 }
1886
1887 #ifdef HEAVY_STATISTICS
1888 extern long long marked_cards;
1889 extern long long scanned_cards;
1890 extern long long scanned_objects;
1891 extern long long remarked_cards;
1892 #endif
1893
1894 #define CARD_WORDS_PER_BLOCK (CARDS_PER_BLOCK / SIZEOF_VOID_P)
1895 /*
1896  * MS blocks are 16K aligned.
1897  * Cardtables are 4K aligned, at least.
1898  * This means that the cardtable of a given block is 32 bytes aligned.
1899  */
1900 static guint8*
1901 initial_skip_card (guint8 *card_data)
1902 {
1903         mword *cards = (mword*)card_data;
1904         mword card;
1905         int i;
1906         for (i = 0; i < CARD_WORDS_PER_BLOCK; ++i) {
1907                 card = cards [i];
1908                 if (card)
1909                         break;
1910         }
1911
1912         if (i == CARD_WORDS_PER_BLOCK)
1913                 return card_data + CARDS_PER_BLOCK;
1914
1915 #if defined(__i386__) && defined(__GNUC__)
1916         return card_data + i * 4 +  (__builtin_ffs (card) - 1) / 8;
1917 #elif defined(__x86_64__) && defined(__GNUC__)
1918         return card_data + i * 8 +  (__builtin_ffsll (card) - 1) / 8;
1919 #elif defined(__s390x__) && defined(__GNUC__)
1920         return card_data + i * 8 +  (__builtin_ffsll (GUINT64_TO_LE(card)) - 1) / 8;
1921 #else
1922         for (i = i * SIZEOF_VOID_P; i < CARDS_PER_BLOCK; ++i) {
1923                 if (card_data [i])
1924                         return &card_data [i];
1925         }
1926         return card_data;
1927 #endif
1928 }
1929
1930
1931 static G_GNUC_UNUSED guint8*
1932 skip_card (guint8 *card_data, guint8 *card_data_end)
1933 {
1934         while (card_data < card_data_end && !*card_data)
1935                 ++card_data;
1936         return card_data;
1937 }
1938
1939 #define MS_BLOCK_OBJ_INDEX_FAST(o,b,os) (((char*)(o) - ((b) + MS_BLOCK_SKIP)) / (os))
1940 #define MS_BLOCK_OBJ_FAST(b,os,i)                       ((b) + MS_BLOCK_SKIP + (os) * (i))
1941 #define MS_OBJ_ALLOCED_FAST(o,b)                (*(void**)(o) && (*(char**)(o) < (b) || *(char**)(o) >= (b) + MS_BLOCK_SIZE))
1942
1943 static void
1944 major_scan_card_table (gboolean mod_union, SgenGrayQueue *queue)
1945 {
1946         MSBlockInfo *block;
1947         gboolean has_references;
1948         ScanObjectFunc scan_func = sgen_get_current_object_ops ()->scan_object;
1949
1950 #ifdef SGEN_HAVE_CONCURRENT_MARK
1951         if (!concurrent_mark)
1952                 g_assert (!mod_union);
1953 #else
1954         g_assert (!mod_union);
1955 #endif
1956
1957         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1958                 int block_obj_size;
1959                 char *block_start;
1960
1961                 if (!has_references)
1962                         continue;
1963
1964                 block_obj_size = block->obj_size;
1965                 block_start = MS_BLOCK_FOR_BLOCK_INFO (block);
1966
1967                 if (block_obj_size >= CARD_SIZE_IN_BYTES) {
1968                         guint8 *cards;
1969 #ifndef SGEN_HAVE_OVERLAPPING_CARDS
1970                         guint8 cards_data [CARDS_PER_BLOCK];
1971 #endif
1972                         char *obj, *end, *base;
1973
1974                         if (mod_union) {
1975 #ifdef SGEN_HAVE_CONCURRENT_MARK
1976                                 cards = block->cardtable_mod_union;
1977                                 /*
1978                                  * This happens when the nursery
1979                                  * collection that precedes finishing
1980                                  * the concurrent collection allocates
1981                                  * new major blocks.
1982                                  */
1983                                 if (!cards)
1984                                         continue;
1985 #endif
1986                         } else {
1987                         /*We can avoid the extra copy since the remark cardtable was cleaned before */
1988 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
1989                                 cards = sgen_card_table_get_card_scan_address ((mword)block_start);
1990 #else
1991                                 cards = cards_data;
1992                                 if (!sgen_card_table_get_card_data (cards_data, (mword)block_start, CARDS_PER_BLOCK))
1993                                         continue;
1994 #endif
1995                         }
1996
1997                         obj = (char*)MS_BLOCK_OBJ_FAST (block_start, block_obj_size, 0);
1998                         end = block_start + MS_BLOCK_SIZE;
1999                         base = sgen_card_table_align_pointer (obj);
2000
2001                         while (obj < end) {
2002                                 size_t card_offset;
2003
2004                                 if (!block->swept)
2005                                         sweep_block (block, FALSE);
2006
2007                                 if (!MS_OBJ_ALLOCED_FAST (obj, block_start))
2008                                         goto next_large;
2009
2010                                 if (mod_union) {
2011                                         /* FIXME: do this more efficiently */
2012                                         int w, b;
2013                                         MS_CALC_MARK_BIT (w, b, obj);
2014                                         if (!MS_MARK_BIT (block, w, b))
2015                                                 goto next_large;
2016                                 }
2017
2018                                 card_offset = (obj - base) >> CARD_BITS;
2019                                 sgen_cardtable_scan_object (obj, block_obj_size, cards + card_offset, mod_union, queue);
2020
2021                         next_large:
2022                                 obj += block_obj_size;
2023                         }
2024                 } else {
2025                         guint8 *card_data, *card_base;
2026                         guint8 *card_data_end;
2027
2028                         /*
2029                          * This is safe in face of card aliasing for the following reason:
2030                          *
2031                          * Major blocks are 16k aligned, or 32 cards aligned.
2032                          * Cards aliasing happens in powers of two, so as long as major blocks are aligned to their
2033                          * sizes, they won't overflow the cardtable overlap modulus.
2034                          */
2035                         if (mod_union) {
2036 #ifdef SGEN_HAVE_CONCURRENT_MARK
2037                                 card_data = card_base = block->cardtable_mod_union;
2038                                 /*
2039                                  * This happens when the nursery
2040                                  * collection that precedes finishing
2041                                  * the concurrent collection allocates
2042                                  * new major blocks.
2043                                  */
2044                                 if (!card_data)
2045                                         continue;
2046 #else
2047                                 g_assert_not_reached ();
2048                                 card_data = NULL;
2049 #endif
2050                         } else {
2051                                 card_data = card_base = sgen_card_table_get_card_scan_address ((mword)block_start);
2052                         }
2053                         card_data_end = card_data + CARDS_PER_BLOCK;
2054
2055                         for (card_data = initial_skip_card (card_data); card_data < card_data_end; ++card_data) { //card_data = skip_card (card_data + 1, card_data_end)) {
2056                                 size_t index;
2057                                 size_t idx = card_data - card_base;
2058                                 char *start = (char*)(block_start + idx * CARD_SIZE_IN_BYTES);
2059                                 char *end = start + CARD_SIZE_IN_BYTES;
2060                                 char *first_obj, *obj;
2061
2062                                 HEAVY_STAT (++scanned_cards);
2063
2064                                 if (!*card_data)
2065                                         continue;
2066
2067                                 if (!block->swept)
2068                                         sweep_block (block, FALSE);
2069
2070                                 HEAVY_STAT (++marked_cards);
2071
2072                                 sgen_card_table_prepare_card_for_scanning (card_data);
2073
2074                                 if (idx == 0)
2075                                         index = 0;
2076                                 else
2077                                         index = MS_BLOCK_OBJ_INDEX_FAST (start, block_start, block_obj_size);
2078
2079                                 obj = first_obj = (char*)MS_BLOCK_OBJ_FAST (block_start, block_obj_size, index);
2080                                 while (obj < end) {
2081                                         if (!MS_OBJ_ALLOCED_FAST (obj, block_start))
2082                                                 goto next_small;
2083
2084                                         if (mod_union) {
2085                                                 /* FIXME: do this more efficiently */
2086                                                 int w, b;
2087                                                 MS_CALC_MARK_BIT (w, b, obj);
2088                                                 if (!MS_MARK_BIT (block, w, b))
2089                                                         goto next_small;
2090                                         }
2091
2092                                         HEAVY_STAT (++scanned_objects);
2093                                         scan_func (obj, sgen_obj_get_descriptor (obj), queue);
2094                                 next_small:
2095                                         obj += block_obj_size;
2096                                 }
2097                                 HEAVY_STAT (if (*card_data) ++remarked_cards);
2098                                 binary_protocol_card_scan (first_obj, obj - first_obj);
2099                         }
2100                 }
2101         } END_FOREACH_BLOCK;
2102 }
2103
2104 static void
2105 major_count_cards (long long *num_total_cards, long long *num_marked_cards)
2106 {
2107         MSBlockInfo *block;
2108         gboolean has_references;
2109         long long total_cards = 0;
2110         long long marked_cards = 0;
2111
2112         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
2113                 guint8 *cards = sgen_card_table_get_card_scan_address ((mword) MS_BLOCK_FOR_BLOCK_INFO (block));
2114                 int i;
2115
2116                 if (!has_references)
2117                         continue;
2118
2119                 total_cards += CARDS_PER_BLOCK;
2120                 for (i = 0; i < CARDS_PER_BLOCK; ++i) {
2121                         if (cards [i])
2122                                 ++marked_cards;
2123                 }
2124         } END_FOREACH_BLOCK;
2125
2126         *num_total_cards = total_cards;
2127         *num_marked_cards = marked_cards;
2128 }
2129
2130 #ifdef SGEN_HAVE_CONCURRENT_MARK
2131 static void
2132 update_cardtable_mod_union (void)
2133 {
2134         MSBlockInfo *block;
2135
2136         FOREACH_BLOCK (block) {
2137                 size_t num_cards;
2138
2139                 block->cardtable_mod_union = sgen_card_table_update_mod_union (block->cardtable_mod_union,
2140                                 MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE, &num_cards);
2141
2142                 SGEN_ASSERT (0, num_cards == CARDS_PER_BLOCK, "Number of cards calculation is wrong");
2143         } END_FOREACH_BLOCK;
2144 }
2145
2146 static guint8*
2147 major_get_cardtable_mod_union_for_object (char *obj)
2148 {
2149         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
2150         return &block->cardtable_mod_union [(obj - (char*)sgen_card_table_align_pointer (MS_BLOCK_FOR_BLOCK_INFO (block))) >> CARD_BITS];
2151 }
2152 #endif
2153
2154 static void
2155 alloc_free_block_lists (MSBlockInfo ***lists)
2156 {
2157         int i;
2158         for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i)
2159                 lists [i] = sgen_alloc_internal_dynamic (sizeof (MSBlockInfo*) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2160 }
2161
2162 #undef pthread_create
2163
2164 static void
2165 post_param_init (SgenMajorCollector *collector)
2166 {
2167         collector->sweeps_lazily = lazy_sweep;
2168 }
2169
2170 #ifdef SGEN_HAVE_CONCURRENT_MARK
2171 static void
2172 sgen_marksweep_init_internal (SgenMajorCollector *collector, gboolean is_concurrent)
2173 #else // SGEN_HAVE_CONCURRENT_MARK
2174 #error unknown configuration
2175 #endif // SGEN_HAVE_CONCURRENT_MARK
2176 {
2177         int i;
2178
2179         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_MS_BLOCK_INFO, sizeof (MSBlockInfo));
2180
2181         num_block_obj_sizes = ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, NULL);
2182         block_obj_sizes = sgen_alloc_internal_dynamic (sizeof (int) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2183         ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, block_obj_sizes);
2184
2185         evacuate_block_obj_sizes = sgen_alloc_internal_dynamic (sizeof (gboolean) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2186         for (i = 0; i < num_block_obj_sizes; ++i)
2187                 evacuate_block_obj_sizes [i] = FALSE;
2188
2189         /*
2190         {
2191                 int i;
2192                 g_print ("block object sizes:\n");
2193                 for (i = 0; i < num_block_obj_sizes; ++i)
2194                         g_print ("%d\n", block_obj_sizes [i]);
2195         }
2196         */
2197
2198         alloc_free_block_lists (free_block_lists);
2199
2200         for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES; ++i)
2201                 fast_block_obj_size_indexes [i] = ms_find_block_obj_size_index (i * 8);
2202         for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES * 8; ++i)
2203                 g_assert (MS_BLOCK_OBJ_SIZE_INDEX (i) == ms_find_block_obj_size_index (i));
2204
2205         mono_counters_register ("# major blocks allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_alloced);
2206         mono_counters_register ("# major blocks freed", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed);
2207         mono_counters_register ("# major blocks lazy swept", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_lazy_swept);
2208         mono_counters_register ("# major objects evacuated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_objects_evacuated);
2209 #if SIZEOF_VOID_P != 8
2210         mono_counters_register ("# major blocks freed ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_ideal);
2211         mono_counters_register ("# major blocks freed less ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_less_ideal);
2212         mono_counters_register ("# major blocks freed individually", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_individual);
2213         mono_counters_register ("# major blocks allocated less ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_alloced_less_ideal);
2214 #endif
2215
2216         collector->section_size = MAJOR_SECTION_SIZE;
2217
2218 #ifdef SGEN_HAVE_CONCURRENT_MARK
2219         concurrent_mark = is_concurrent;
2220         if (is_concurrent) {
2221                 collector->is_concurrent = TRUE;
2222                 collector->want_synchronous_collection = &want_evacuation;
2223         } else
2224 #endif
2225         {
2226                 collector->is_concurrent = FALSE;
2227                 collector->want_synchronous_collection = NULL;
2228         }
2229         collector->get_and_reset_num_major_objects_marked = major_get_and_reset_num_major_objects_marked;
2230         collector->supports_cardtable = TRUE;
2231
2232         collector->have_swept = &have_swept;
2233
2234         collector->alloc_heap = major_alloc_heap;
2235         collector->is_object_live = major_is_object_live;
2236         collector->alloc_small_pinned_obj = major_alloc_small_pinned_obj;
2237         collector->alloc_degraded = major_alloc_degraded;
2238
2239         collector->alloc_object = major_alloc_object;
2240         collector->free_pinned_object = free_pinned_object;
2241         collector->iterate_objects = major_iterate_objects;
2242         collector->free_non_pinned_object = major_free_non_pinned_object;
2243         collector->find_pin_queue_start_ends = major_find_pin_queue_start_ends;
2244         collector->pin_objects = major_pin_objects;
2245         collector->pin_major_object = pin_major_object;
2246         collector->scan_card_table = major_scan_card_table;
2247         collector->iterate_live_block_ranges = (void*)(void*) major_iterate_live_block_ranges;
2248 #ifdef SGEN_HAVE_CONCURRENT_MARK
2249         if (is_concurrent) {
2250                 collector->update_cardtable_mod_union = update_cardtable_mod_union;
2251                 collector->get_cardtable_mod_union_for_object = major_get_cardtable_mod_union_for_object;
2252         }
2253 #endif
2254         collector->init_to_space = major_init_to_space;
2255         collector->sweep = major_sweep;
2256         collector->check_scan_starts = major_check_scan_starts;
2257         collector->dump_heap = major_dump_heap;
2258         collector->get_used_size = major_get_used_size;
2259         collector->start_nursery_collection = major_start_nursery_collection;
2260         collector->finish_nursery_collection = major_finish_nursery_collection;
2261         collector->start_major_collection = major_start_major_collection;
2262         collector->finish_major_collection = major_finish_major_collection;
2263         collector->have_computed_minor_collection_allowance = major_have_computer_minor_collection_allowance;
2264         collector->ptr_is_in_non_pinned_space = major_ptr_is_in_non_pinned_space;
2265         collector->obj_is_from_pinned_alloc = obj_is_from_pinned_alloc;
2266         collector->report_pinned_memory_usage = major_report_pinned_memory_usage;
2267         collector->get_num_major_sections = get_num_major_sections;
2268         collector->handle_gc_param = major_handle_gc_param;
2269         collector->print_gc_param_usage = major_print_gc_param_usage;
2270         collector->post_param_init = post_param_init;
2271         collector->is_valid_object = major_is_valid_object;
2272         collector->describe_pointer = major_describe_pointer;
2273         collector->count_cards = major_count_cards;
2274
2275         collector->major_ops.copy_or_mark_object = major_copy_or_mark_object_canonical;
2276         collector->major_ops.scan_object = major_scan_object;
2277 #ifdef SGEN_HAVE_CONCURRENT_MARK
2278         if (is_concurrent) {
2279                 collector->major_concurrent_ops.copy_or_mark_object = major_copy_or_mark_object_concurrent_canonical;
2280                 collector->major_concurrent_ops.scan_object = major_scan_object_concurrent;
2281                 collector->major_concurrent_ops.scan_vtype = major_scan_vtype_concurrent;
2282         }
2283 #endif
2284
2285 #if !defined (FIXED_HEAP) && !defined (SGEN_PARALLEL_MARK)
2286         /* FIXME: this will not work with evacuation or the split nursery. */
2287         if (!is_concurrent)
2288                 collector->drain_gray_stack = drain_gray_stack;
2289
2290 #ifdef HEAVY_STATISTICS
2291         mono_counters_register ("Optimized copy object called", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_copy_object_called);
2292         mono_counters_register ("Optimized nursery", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_nursery);
2293         mono_counters_register ("Optimized nursery forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_nursery_forwarded);
2294         mono_counters_register ("Optimized nursery pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_nursery_pinned);
2295         mono_counters_register ("Optimized major mark", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_mark);
2296         mono_counters_register ("Optimized major mark small", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_mark_small);
2297         mono_counters_register ("Optimized major mark large", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_mark_large);
2298         mono_counters_register ("Optimized major scan", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_scan);
2299         mono_counters_register ("Optimized major scan slow", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_scan_slow);
2300         mono_counters_register ("Optimized major scan fast", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_scan_fast);
2301
2302         mono_counters_register ("Gray stack drain loops", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_drain_loops);
2303         mono_counters_register ("Gray stack prefetch fills", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_drain_prefetch_fills);
2304         mono_counters_register ("Gray stack prefetch failures", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_drain_prefetch_fill_failures);
2305 #endif
2306 #endif
2307
2308 #ifdef HEAVY_STATISTICS
2309         mono_mutex_init (&scanned_objects_list_lock);
2310 #endif
2311
2312         SGEN_ASSERT (0, SGEN_MAX_SMALL_OBJ_SIZE <= MS_BLOCK_FREE / 2, "MAX_SMALL_OBJ_SIZE must be at most MS_BLOCK_FREE / 2");
2313
2314         /*cardtable requires major pages to be 8 cards aligned*/
2315         g_assert ((MS_BLOCK_SIZE % (8 * CARD_SIZE_IN_BYTES)) == 0);
2316 }
2317
2318 #ifdef SGEN_HAVE_CONCURRENT_MARK
2319 void
2320 sgen_marksweep_init (SgenMajorCollector *collector)
2321 {
2322         sgen_marksweep_init_internal (collector, FALSE);
2323 }
2324
2325 void
2326 sgen_marksweep_conc_init (SgenMajorCollector *collector)
2327 {
2328         sgen_marksweep_init_internal (collector, TRUE);
2329 }
2330 #endif
2331
2332 #endif