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   16
  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 #if SGEN_MAX_SMALL_OBJ_SIZE > MS_BLOCK_FREE / 2
  72 #error MAX_SMALL_OBJ_SIZE must be at most MS_BLOCK_FREE / 2
  73 #endif
  74
  75 typedef struct _MSBlockInfo MSBlockInfo;
  76 struct _MSBlockInfo {
  77         int obj_size;
  78         int obj_size_index;
  79         unsigned int pinned : 1;
  80         unsigned int has_references : 1;
  81         unsigned int has_pinned : 1;    /* means cannot evacuate */
  82         unsigned int is_to_space : 1;
  83         unsigned int swept : 1;
  84         char *block;
  85         void **free_list;
  86         MSBlockInfo *next_free;
  87         size_t pin_queue_first_entry;
  88         size_t pin_queue_last_entry;
  89 #ifdef SGEN_HAVE_CONCURRENT_MARK
  90         guint8 *cardtable_mod_union;
  91 #endif
  92         mword mark_words [MS_NUM_MARK_WORDS];
  93 };
  94
  95 #define MS_BLOCK_FOR_BLOCK_INFO(b)      ((b)->block)
  96
  97 #define MS_BLOCK_OBJ(b,i)               (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (b)->obj_size * (i))
  98 #define MS_BLOCK_OBJ_FOR_SIZE(b,i,obj_size)             (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (obj_size) * (i))
  99 #define MS_BLOCK_DATA_FOR_OBJ(o)        ((char*)((mword)(o) & ~(mword)(MS_BLOCK_SIZE - 1)))
 100
 101 typedef struct {
 102         MSBlockInfo *info;
 103 } MSBlockHeader;
 104
 105 #define MS_BLOCK_FOR_OBJ(o)             (((MSBlockHeader*)MS_BLOCK_DATA_FOR_OBJ ((o)))->info)
 106
 107 /* object index will always be small */
 108 #define MS_BLOCK_OBJ_INDEX(o,b) ((int)(((char*)(o) - (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP)) / (b)->obj_size))
 109
 110 //casting to int is fine since blocks are 32k
 111 #define MS_CALC_MARK_BIT(w,b,o)         do {                            \
 112                 int i = ((int)((char*)(o) - MS_BLOCK_DATA_FOR_OBJ ((o)))) >> SGEN_ALLOC_ALIGN_BITS; \
 113                 if (sizeof (mword) == 4) {                              \
 114                         (w) = i >> 5;                                   \
 115                         (b) = i & 31;                                   \
 116                 } else {                                                \
 117                         (w) = i >> 6;                                   \
 118                         (b) = i & 63;                                   \
 119                 }                                                       \
 120         } while (0)
 121
 122 #define MS_MARK_BIT(bl,w,b)     ((bl)->mark_words [(w)] & (ONE_P << (b)))
 123 #define MS_SET_MARK_BIT(bl,w,b) ((bl)->mark_words [(w)] |= (ONE_P << (b)))
 124
 125 #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))
 126
 127 #define MS_BLOCK_OBJ_SIZE_FACTOR        (sqrt (2.0))
 128
 129 /*
 130  * This way we can lookup block object size indexes for sizes up to
 131  * 256 bytes with a single load.
 132  */
 133 #define MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES      32
 134
 135 static int *block_obj_sizes;
 136 static int num_block_obj_sizes;
 137 static int fast_block_obj_size_indexes [MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES];
 138
 139 #define MS_BLOCK_FLAG_PINNED    1
 140 #define MS_BLOCK_FLAG_REFS      2
 141
 142 #define MS_BLOCK_TYPE_MAX       4
 143
 144 static gboolean *evacuate_block_obj_sizes;
 145 static float evacuation_threshold = 0.0f;
 146 #ifdef SGEN_HAVE_CONCURRENT_MARK
 147 static float concurrent_evacuation_threshold = 0.0f;
 148 static gboolean want_evacuation = FALSE;
 149 #endif
 150
 151 static gboolean lazy_sweep = TRUE;
 152 static gboolean have_swept;
 153
 154 #ifdef SGEN_HAVE_CONCURRENT_MARK
 155 static gboolean concurrent_mark;
 156 #endif
 157
 158 #define BLOCK_IS_TAGGED_HAS_REFERENCES(bl)      SGEN_POINTER_IS_TAGGED_1 ((bl))
 159 #define BLOCK_TAG_HAS_REFERENCES(bl)            SGEN_POINTER_TAG_1 ((bl))
 160 #define BLOCK_UNTAG_HAS_REFERENCES(bl)          SGEN_POINTER_UNTAG_1 ((bl))
 161
 162 #define BLOCK_TAG(bl)   ((bl)->has_references ? BLOCK_TAG_HAS_REFERENCES ((bl)) : (bl))
 163
 164 /* all allocated blocks in the system */
 165 static SgenPointerQueue allocated_blocks;
 166
 167 /* non-allocated block free-list */
 168 static void *empty_blocks = NULL;
 169 static size_t num_empty_blocks = 0;
 170
 171 #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]);
 172 #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));
 173 #define END_FOREACH_BLOCK       } }
 174 #define DELETE_BLOCK_IN_FOREACH()       (allocated_blocks.data [__index] = NULL)
 175
 176 static size_t num_major_sections = 0;
 177 /* one free block list for each block object size */
 178 static MSBlockInfo **free_block_lists [MS_BLOCK_TYPE_MAX];
 179
 180 static long long stat_major_blocks_alloced = 0;
 181 static long long stat_major_blocks_freed = 0;
 182 static long long stat_major_blocks_lazy_swept = 0;
 183 static long long stat_major_objects_evacuated = 0;
 184
 185 #if SIZEOF_VOID_P != 8
 186 static long long stat_major_blocks_freed_ideal = 0;
 187 static long long stat_major_blocks_freed_less_ideal = 0;
 188 static long long stat_major_blocks_freed_individual = 0;
 189 static long long stat_major_blocks_alloced_less_ideal = 0;
 190 #endif
 191
 192 #ifdef SGEN_COUNT_NUMBER_OF_MAJOR_OBJECTS_MARKED
 193 static long long num_major_objects_marked = 0;
 194 #define INC_NUM_MAJOR_OBJECTS_MARKED()  (++num_major_objects_marked)
 195 #else
 196 #define INC_NUM_MAJOR_OBJECTS_MARKED()
 197 #endif
 198
 199 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
 200 static mono_mutex_t scanned_objects_list_lock;
 201 static SgenPointerQueue scanned_objects_list;
 202
 203 static void
 204 add_scanned_object (void *ptr)
 205 {
 206         if (!binary_protocol_is_enabled ())
 207                 return;
 208
 209         mono_mutex_lock (&scanned_objects_list_lock);
 210         sgen_pointer_queue_add (&scanned_objects_list, ptr);
 211         mono_mutex_unlock (&scanned_objects_list_lock);
 212 }
 213 #endif
 214
 215 static void
 216 sweep_block (MSBlockInfo *block, gboolean during_major_collection);
 217
 218 static int
 219 ms_find_block_obj_size_index (size_t size)
 220 {
 221         int i;
 222         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);
 223         for (i = 0; i < num_block_obj_sizes; ++i)
 224                 if (block_obj_sizes [i] >= size)
 225                         return i;
 226         g_error ("no object of size %d\n", size);
 227 }
 228
 229 #define FREE_BLOCKS_FROM(lists,p,r)     (lists [((p) ? MS_BLOCK_FLAG_PINNED : 0) | ((r) ? MS_BLOCK_FLAG_REFS : 0)])
 230 #define FREE_BLOCKS(p,r)                (FREE_BLOCKS_FROM (free_block_lists, (p), (r)))
 231
 232 #define MS_BLOCK_OBJ_SIZE_INDEX(s)                              \
 233         (((s)+7)>>3 < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES ?      \
 234          fast_block_obj_size_indexes [((s)+7)>>3] :             \
 235          ms_find_block_obj_size_index ((s)))
 236
 237 static void*
 238 major_alloc_heap (mword nursery_size, mword nursery_align, int the_nursery_bits)
 239 {
 240         char *start;
 241         if (nursery_align)
 242                 start = sgen_alloc_os_memory_aligned (nursery_size, nursery_align, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE, "nursery");
 243         else
 244                 start = sgen_alloc_os_memory (nursery_size, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE, "nursery");
 245
 246         return start;
 247 }
 248
 249 static void
 250 update_heap_boundaries_for_block (MSBlockInfo *block)
 251 {
 252         sgen_update_heap_boundaries ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), (mword)MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE);
 253 }
 254
 255 static void*
 256 ms_get_empty_block (void)
 257 {
 258         char *p;
 259         int i;
 260         void *block, *empty, *next;
 261
 262  retry:
 263         if (!empty_blocks) {
 264                 /*
 265                  * We try allocating MS_BLOCK_ALLOC_NUM blocks first.  If that's
 266                  * unsuccessful, we halve the number of blocks and try again, until we're at
 267                  * 1.  If that doesn't work, either, we assert.
 268                  */
 269                 int alloc_num = MS_BLOCK_ALLOC_NUM;
 270                 for (;;) {
 271                         p = sgen_alloc_os_memory_aligned (MS_BLOCK_SIZE * alloc_num, MS_BLOCK_SIZE, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE,
 272                                         alloc_num == 1 ? "major heap section" : NULL);
 273                         if (p)
 274                                 break;
 275                         alloc_num >>= 1;
 276                 }
 277
 278                 for (i = 0; i < alloc_num; ++i) {
 279                         block = p;
 280                         /*
 281                          * We do the free list update one after the
 282                          * other so that other threads can use the new
 283                          * blocks as quickly as possible.
 284                          */
 285                         do {
 286                                 empty = empty_blocks;
 287                                 *(void**)block = empty;
 288                         } while (SGEN_CAS_PTR ((gpointer*)&empty_blocks, block, empty) != empty);
 289                         p += MS_BLOCK_SIZE;
 290                 }
 291
 292                 SGEN_ATOMIC_ADD_P (num_empty_blocks, alloc_num);
 293
 294                 stat_major_blocks_alloced += alloc_num;
 295 #if SIZEOF_VOID_P != 8
 296                 if (alloc_num != MS_BLOCK_ALLOC_NUM)
 297                         stat_major_blocks_alloced_less_ideal += alloc_num;
 298 #endif
 299         }
 300
 301         do {
 302                 empty = empty_blocks;
 303                 if (!empty)
 304                         goto retry;
 305                 block = empty;
 306                 next = *(void**)block;
 307         } while (SGEN_CAS_PTR (&empty_blocks, next, empty) != empty);
 308
 309         SGEN_ATOMIC_ADD_P (num_empty_blocks, -1);
 310
 311         *(void**)block = NULL;
 312
 313         g_assert (!((mword)block & (MS_BLOCK_SIZE - 1)));
 314
 315         return block;
 316 }
 317
 318 static void
 319 ms_free_block (void *block)
 320 {
 321         void *empty;
 322
 323         sgen_memgov_release_space (MS_BLOCK_SIZE, SPACE_MAJOR);
 324         memset (block, 0, MS_BLOCK_SIZE);
 325
 326         do {
 327                 empty = empty_blocks;
 328                 *(void**)block = empty;
 329         } while (SGEN_CAS_PTR (&empty_blocks, block, empty) != empty);
 330
 331         SGEN_ATOMIC_ADD_P (num_empty_blocks, 1);
 332 }
 333
 334 //#define MARKSWEEP_CONSISTENCY_CHECK
 335
 336 #ifdef MARKSWEEP_CONSISTENCY_CHECK
 337 static void
 338 check_block_free_list (MSBlockInfo *block, int size, gboolean pinned)
 339 {
 340         MSBlockInfo *b;
 341
 342         for (; block; block = block->next_free) {
 343                 g_assert (block->obj_size == size);
 344                 g_assert ((pinned && block->pinned) || (!pinned && !block->pinned));
 345
 346                 /* blocks in the free lists must have at least
 347                    one free slot */
 348                 if (block->swept)
 349                         g_assert (block->free_list);
 350
 351                 /* the block must be in the allocated_blocks array */
 352                 g_assert (sgen_pointer_queue_find (&allocated_blocks, BLOCK_TAG (block)) != (size_t)-1);
 353         }
 354 }
 355
 356 static void
 357 check_empty_blocks (void)
 358 {
 359         void *p;
 360         size_t i = 0;
 361         for (p = empty_blocks; p; p = *(void**)p)
 362                 ++i;
 363         g_assert (i == num_empty_blocks);
 364 }
 365
 366 static void
 367 consistency_check (void)
 368 {
 369         MSBlockInfo *block;
 370         int i;
 371
 372         /* check all blocks */
 373         FOREACH_BLOCK (block) {
 374                 int count = MS_BLOCK_FREE / block->obj_size;
 375                 int num_free = 0;
 376                 void **free;
 377
 378                 /* check block header */
 379                 g_assert (((MSBlockHeader*)block->block)->info == block);
 380
 381                 /* count number of free slots */
 382                 for (i = 0; i < count; ++i) {
 383                         void **obj = (void**) MS_BLOCK_OBJ (block, i);
 384                         if (!MS_OBJ_ALLOCED (obj, block))
 385                                 ++num_free;
 386                 }
 387
 388                 /* check free list */
 389                 for (free = block->free_list; free; free = (void**)*free) {
 390                         g_assert (MS_BLOCK_FOR_OBJ (free) == block);
 391                         --num_free;
 392                 }
 393                 g_assert (num_free == 0);
 394
 395                 /* check all mark words are zero */
 396                 if (block->swept) {
 397                         for (i = 0; i < MS_NUM_MARK_WORDS; ++i)
 398                                 g_assert (block->mark_words [i] == 0);
 399                 }
 400         } END_FOREACH_BLOCK;
 401
 402         /* check free blocks */
 403         for (i = 0; i < num_block_obj_sizes; ++i) {
 404                 int j;
 405                 for (j = 0; j < MS_BLOCK_TYPE_MAX; ++j)
 406                         check_block_free_list (free_block_lists [j][i], block_obj_sizes [i], j & MS_BLOCK_FLAG_PINNED);
 407         }
 408
 409         check_empty_blocks ();
 410 }
 411 #endif
 412
 413 static gboolean
 414 ms_alloc_block (int size_index, gboolean pinned, gboolean has_references)
 415 {
 416         int size = block_obj_sizes [size_index];
 417         int count = MS_BLOCK_FREE / size;
 418         MSBlockInfo *info;
 419         MSBlockHeader *header;
 420         MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, has_references);
 421         char *obj_start;
 422         int i;
 423
 424         if (!sgen_memgov_try_alloc_space (MS_BLOCK_SIZE, SPACE_MAJOR))
 425                 return FALSE;
 426
 427         info = sgen_alloc_internal (INTERNAL_MEM_MS_BLOCK_INFO);
 428
 429         SGEN_ASSERT (9, count >= 2, "block with %d objects, it must hold at least 2", count);
 430
 431         info->obj_size = size;
 432         info->obj_size_index = size_index;
 433         info->pinned = pinned;
 434         info->has_references = has_references;
 435         info->has_pinned = pinned;
 436         /*
 437          * Blocks that are to-space are not evacuated from.  During an major collection
 438          * blocks are allocated for two reasons: evacuating objects from the nursery and
 439          * evacuating them from major blocks marked for evacuation.  In both cases we don't
 440          * want further evacuation.
 441          */
 442         info->is_to_space = (sgen_get_current_collection_generation () == GENERATION_OLD);
 443         info->swept = 1;
 444         info->block = ms_get_empty_block ();
 445
 446         header = (MSBlockHeader*) info->block;
 447         header->info = info;
 448 #ifdef SGEN_HAVE_CONCURRENT_MARK
 449         info->cardtable_mod_union = NULL;
 450 #endif
 451
 452         update_heap_boundaries_for_block (info);
 453
 454         /* build free list */
 455         obj_start = MS_BLOCK_FOR_BLOCK_INFO (info) + MS_BLOCK_SKIP;
 456         info->free_list = (void**)obj_start;
 457         /* we're skipping the last one - it must be nulled */
 458         for (i = 0; i < count - 1; ++i) {
 459                 char *next_obj_start = obj_start + size;
 460                 *(void**)obj_start = next_obj_start;
 461                 obj_start = next_obj_start;
 462         }
 463         /* the last one */
 464         *(void**)obj_start = NULL;
 465
 466         info->next_free = free_blocks [size_index];
 467         free_blocks [size_index] = info;
 468
 469         sgen_pointer_queue_add (&allocated_blocks, BLOCK_TAG (info));
 470
 471         ++num_major_sections;
 472         return TRUE;
 473 }
 474
 475 static gboolean
 476 obj_is_from_pinned_alloc (char *ptr)
 477 {
 478         MSBlockInfo *block;
 479
 480         FOREACH_BLOCK (block) {
 481                 if (ptr >= MS_BLOCK_FOR_BLOCK_INFO (block) && ptr <= MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE)
 482                         return block->pinned;
 483         } END_FOREACH_BLOCK;
 484         return FALSE;
 485 }
 486
 487 static void*
 488 unlink_slot_from_free_list_uncontested (MSBlockInfo **free_blocks, int size_index)
 489 {
 490         MSBlockInfo *block;
 491         void *obj;
 492
 493         block = free_blocks [size_index];
 494         SGEN_ASSERT (9, block, "no free block to unlink from free_blocks %p size_index %d", free_blocks, size_index);
 495
 496         if (G_UNLIKELY (!block->swept)) {
 497                 stat_major_blocks_lazy_swept ++;
 498                 sweep_block (block, FALSE);
 499         }
 500
 501         obj = block->free_list;
 502         SGEN_ASSERT (9, obj, "block %p in free list had no available object to alloc from", block);
 503
 504         block->free_list = *(void**)obj;
 505         if (!block->free_list) {
 506                 free_blocks [size_index] = block->next_free;
 507                 block->next_free = NULL;
 508         }
 509
 510         return obj;
 511 }
 512
 513 static void*
 514 alloc_obj (MonoVTable *vtable, size_t size, gboolean pinned, gboolean has_references)
 515 {
 516         int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
 517         MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, has_references);
 518         void *obj;
 519
 520         if (!free_blocks [size_index]) {
 521                 if (G_UNLIKELY (!ms_alloc_block (size_index, pinned, has_references)))
 522                         return NULL;
 523         }
 524
 525         obj = unlink_slot_from_free_list_uncontested (free_blocks, size_index);
 526
 527         *(MonoVTable**)obj = vtable;
 528
 529         return obj;
 530 }
 531
 532 static void*
 533 major_alloc_object (MonoVTable *vtable, size_t size, gboolean has_references)
 534 {
 535         return alloc_obj (vtable, size, FALSE, has_references);
 536 }
 537
 538 /*
 539  * We're not freeing the block if it's empty.  We leave that work for
 540  * the next major collection.
 541  *
 542  * This is just called from the domain clearing code, which runs in a
 543  * single thread and has the GC lock, so we don't need an extra lock.
 544  */
 545 static void
 546 free_object (char *obj, size_t size, gboolean pinned)
 547 {
 548         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
 549         int word, bit;
 550
 551         if (!block->swept)
 552                 sweep_block (block, FALSE);
 553         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);
 554         SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p is already free", obj);
 555         MS_CALC_MARK_BIT (word, bit, obj);
 556         SGEN_ASSERT (9, !MS_MARK_BIT (block, word, bit), "object %p has mark bit set");
 557         if (!block->free_list) {
 558                 MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, block->has_references);
 559                 int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
 560                 SGEN_ASSERT (9, !block->next_free, "block %p doesn't have a free-list of object but belongs to a free-list of blocks");
 561                 block->next_free = free_blocks [size_index];
 562                 free_blocks [size_index] = block;
 563         }
 564         memset (obj, 0, size);
 565         *(void**)obj = block->free_list;
 566         block->free_list = (void**)obj;
 567 }
 568
 569 static void
 570 major_free_non_pinned_object (char *obj, size_t size)
 571 {
 572         free_object (obj, size, FALSE);
 573 }
 574
 575 /* size is a multiple of SGEN_ALLOC_ALIGN */
 576 static void*
 577 major_alloc_small_pinned_obj (MonoVTable *vtable, size_t size, gboolean has_references)
 578 {
 579         void *res;
 580
 581         res = alloc_obj (vtable, size, TRUE, has_references);
 582          /*If we failed to alloc memory, we better try releasing memory
 583           *as pinned alloc is requested by the runtime.
 584           */
 585          if (!res) {
 586                 sgen_perform_collection (0, GENERATION_OLD, "pinned alloc failure", TRUE);
 587                 res = alloc_obj (vtable, size, TRUE, has_references);
 588          }
 589          return res;
 590 }
 591
 592 static void
 593 free_pinned_object (char *obj, size_t size)
 594 {
 595         free_object (obj, size, TRUE);
 596 }
 597
 598 /*
 599  * size is already rounded up and we hold the GC lock.
 600  */
 601 static void*
 602 major_alloc_degraded (MonoVTable *vtable, size_t size)
 603 {
 604         void *obj;
 605         size_t old_num_sections;
 606
 607         old_num_sections = num_major_sections;
 608
 609         obj = alloc_obj (vtable, size, FALSE, SGEN_VTABLE_HAS_REFERENCES (vtable));
 610         if (G_LIKELY (obj)) {
 611                 HEAVY_STAT (++stat_objects_alloced_degraded);
 612                 HEAVY_STAT (stat_bytes_alloced_degraded += size);
 613                 g_assert (num_major_sections >= old_num_sections);
 614                 sgen_register_major_sections_alloced (num_major_sections - old_num_sections);
 615         }
 616         return obj;
 617 }
 618
 619 /*
 620  * obj is some object.  If it's not in the major heap (i.e. if it's in
 621  * the nursery or LOS), return FALSE.  Otherwise return whether it's
 622  * been marked or copied.
 623  */
 624 static gboolean
 625 major_is_object_live (char *obj)
 626 {
 627         MSBlockInfo *block;
 628         int word, bit;
 629         mword objsize;
 630
 631         if (sgen_ptr_in_nursery (obj))
 632                 return FALSE;
 633
 634         objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
 635
 636         /* LOS */
 637         if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
 638                 return FALSE;
 639
 640         /* now we know it's in a major block */
 641         block = MS_BLOCK_FOR_OBJ (obj);
 642         SGEN_ASSERT (9, !block->pinned, "block %p is pinned, BTW why is this bad?");
 643         MS_CALC_MARK_BIT (word, bit, obj);
 644         return MS_MARK_BIT (block, word, bit) ? TRUE : FALSE;
 645 }
 646
 647 static gboolean
 648 major_ptr_is_in_non_pinned_space (char *ptr, char **start)
 649 {
 650         MSBlockInfo *block;
 651
 652         FOREACH_BLOCK (block) {
 653                 if (ptr >= MS_BLOCK_FOR_BLOCK_INFO (block) && ptr <= MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) {
 654                         int count = MS_BLOCK_FREE / block->obj_size;
 655                         int i;
 656
 657                         *start = NULL;
 658                         for (i = 0; i <= count; ++i) {
 659                                 if (ptr >= MS_BLOCK_OBJ (block, i) && ptr < MS_BLOCK_OBJ (block, i + 1)) {
 660                                         *start = MS_BLOCK_OBJ (block, i);
 661                                         break;
 662                                 }
 663                         }
 664                         return !block->pinned;
 665                 }
 666         } END_FOREACH_BLOCK;
 667         return FALSE;
 668 }
 669
 670 static void
 671 major_iterate_objects (IterateObjectsFlags flags, IterateObjectCallbackFunc callback, void *data)
 672 {
 673         gboolean sweep = flags & ITERATE_OBJECTS_SWEEP;
 674         gboolean non_pinned = flags & ITERATE_OBJECTS_NON_PINNED;
 675         gboolean pinned = flags & ITERATE_OBJECTS_PINNED;
 676         MSBlockInfo *block;
 677
 678         FOREACH_BLOCK (block) {
 679                 int count = MS_BLOCK_FREE / block->obj_size;
 680                 int i;
 681
 682                 if (block->pinned && !pinned)
 683                         continue;
 684                 if (!block->pinned && !non_pinned)
 685                         continue;
 686                 if (sweep && lazy_sweep) {
 687                         sweep_block (block, FALSE);
 688                         SGEN_ASSERT (0, block->swept, "Block must be swept after sweeping");
 689                 }
 690
 691                 for (i = 0; i < count; ++i) {
 692                         void **obj = (void**) MS_BLOCK_OBJ (block, i);
 693                         if (!block->swept) {
 694                                 int word, bit;
 695                                 MS_CALC_MARK_BIT (word, bit, obj);
 696                                 if (!MS_MARK_BIT (block, word, bit))
 697                                         continue;
 698                         }
 699                         if (MS_OBJ_ALLOCED (obj, block))
 700                                 callback ((char*)obj, block->obj_size, data);
 701                 }
 702         } END_FOREACH_BLOCK;
 703 }
 704
 705 static gboolean
 706 major_is_valid_object (char *object)
 707 {
 708         MSBlockInfo *block;
 709
 710         FOREACH_BLOCK (block) {
 711                 int idx;
 712                 char *obj;
 713
 714                 if ((MS_BLOCK_FOR_BLOCK_INFO (block) > object) || ((MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) <= object))
 715                         continue;
 716
 717                 idx = MS_BLOCK_OBJ_INDEX (object, block);
 718                 obj = (char*)MS_BLOCK_OBJ (block, idx);
 719                 if (obj != object)
 720                         return FALSE;
 721                 return MS_OBJ_ALLOCED (obj, block);
 722         } END_FOREACH_BLOCK;
 723
 724         return FALSE;
 725 }
 726
 727
 728 static MonoVTable*
 729 major_describe_pointer (char *ptr)
 730 {
 731         MSBlockInfo *block;
 732
 733         FOREACH_BLOCK (block) {
 734                 int idx;
 735                 char *obj;
 736                 gboolean live;
 737                 MonoVTable *vtable;
 738                 int w, b;
 739                 gboolean marked;
 740
 741                 if ((MS_BLOCK_FOR_BLOCK_INFO (block) > ptr) || ((MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) <= ptr))
 742                         continue;
 743
 744                 SGEN_LOG (0, "major-ptr (block %p sz %d pin %d ref %d)\n",
 745                         MS_BLOCK_FOR_BLOCK_INFO (block), block->obj_size, block->pinned, block->has_references);
 746
 747                 idx = MS_BLOCK_OBJ_INDEX (ptr, block);
 748                 obj = (char*)MS_BLOCK_OBJ (block, idx);
 749                 live = MS_OBJ_ALLOCED (obj, block);
 750                 vtable = live ? (MonoVTable*)SGEN_LOAD_VTABLE (obj) : NULL;
 751
 752                 MS_CALC_MARK_BIT (w, b, obj);
 753                 marked = MS_MARK_BIT (block, w, b);
 754
 755                 if (obj == ptr) {
 756                         SGEN_LOG (0, "\t(");
 757                         if (live)
 758                                 SGEN_LOG (0, "object");
 759                         else
 760                                 SGEN_LOG (0, "dead-object");
 761                 } else {
 762                         if (live)
 763                                 SGEN_LOG (0, "interior-ptr offset %td", ptr - obj);
 764                         else
 765                                 SGEN_LOG (0, "dead-interior-ptr offset %td", ptr - obj);
 766                 }
 767
 768                 SGEN_LOG (0, " marked %d)\n", marked ? 1 : 0);
 769
 770                 return vtable;
 771         } END_FOREACH_BLOCK;
 772
 773         return NULL;
 774 }
 775
 776 static void
 777 major_check_scan_starts (void)
 778 {
 779 }
 780
 781 static void
 782 major_dump_heap (FILE *heap_dump_file)
 783 {
 784         MSBlockInfo *block;
 785         int *slots_available = alloca (sizeof (int) * num_block_obj_sizes);
 786         int *slots_used = alloca (sizeof (int) * num_block_obj_sizes);
 787         int i;
 788
 789         for (i = 0; i < num_block_obj_sizes; ++i)
 790                 slots_available [i] = slots_used [i] = 0;
 791
 792         FOREACH_BLOCK (block) {
 793                 int index = ms_find_block_obj_size_index (block->obj_size);
 794                 int count = MS_BLOCK_FREE / block->obj_size;
 795
 796                 slots_available [index] += count;
 797                 for (i = 0; i < count; ++i) {
 798                         if (MS_OBJ_ALLOCED (MS_BLOCK_OBJ (block, i), block))
 799                                 ++slots_used [index];
 800                 }
 801         } END_FOREACH_BLOCK;
 802
 803         fprintf (heap_dump_file, "<occupancies>\n");
 804         for (i = 0; i < num_block_obj_sizes; ++i) {
 805                 fprintf (heap_dump_file, "<occupancy size=\"%d\" available=\"%d\" used=\"%d\" />\n",
 806                                 block_obj_sizes [i], slots_available [i], slots_used [i]);
 807         }
 808         fprintf (heap_dump_file, "</occupancies>\n");
 809
 810         FOREACH_BLOCK (block) {
 811                 int count = MS_BLOCK_FREE / block->obj_size;
 812                 int i;
 813                 int start = -1;
 814
 815                 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%zu\">\n", "old", (size_t)MS_BLOCK_FREE);
 816
 817                 for (i = 0; i <= count; ++i) {
 818                         if ((i < count) && MS_OBJ_ALLOCED (MS_BLOCK_OBJ (block, i), block)) {
 819                                 if (start < 0)
 820                                         start = i;
 821                         } else {
 822                                 if (start >= 0) {
 823                                         sgen_dump_occupied (MS_BLOCK_OBJ (block, start), MS_BLOCK_OBJ (block, i), MS_BLOCK_FOR_BLOCK_INFO (block));
 824                                         start = -1;
 825                                 }
 826                         }
 827                 }
 828
 829                 fprintf (heap_dump_file, "</section>\n");
 830         } END_FOREACH_BLOCK;
 831 }
 832
 833 #define LOAD_VTABLE     SGEN_LOAD_VTABLE
 834
 835 #define MS_MARK_OBJECT_AND_ENQUEUE_CHECKED(obj,desc,block,queue) do {   \
 836                 int __word, __bit;                                      \
 837                 SGEN_ASSERT (0, sgen_get_current_collection_generation () == GENERATION_OLD, "Can't majorly enqueue objects when doing minor collection"); \
 838                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 839                 if (MS_OBJ_ALLOCED ((obj), (block))) { \
 840                         if ((block)->has_references) {                  \
 841                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 842                         } else {                                        \
 843                                 MS_SET_MARK_BIT ((block), __word, __bit); \
 844                                 binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 845                         }                                               \
 846                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 847                 }                                                       \
 848         } while (0)
 849 #define MS_MARK_OBJECT_AND_ENQUEUE(obj,desc,block,queue) do {           \
 850                 int __word, __bit;                                      \
 851                 SGEN_ASSERT (0, sgen_get_current_collection_generation () == GENERATION_OLD, "Can't majorly enqueue objects when doing minor collection"); \
 852                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 853                 SGEN_ASSERT (9, MS_OBJ_ALLOCED ((obj), (block)), "object %p not allocated", obj);       \
 854                 {               \
 855                         if ((block)->has_references) {                  \
 856                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 857                         } else {                                        \
 858                                 MS_SET_MARK_BIT ((block), __word, __bit); \
 859                                 binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 860                         }                                               \
 861                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 862                 }                                                       \
 863         } while (0)
 864
 865 static void
 866 pin_major_object (char *obj, SgenGrayQueue *queue)
 867 {
 868         MSBlockInfo *block;
 869
 870 #ifdef SGEN_HAVE_CONCURRENT_MARK
 871         if (concurrent_mark)
 872                 g_assert_not_reached ();
 873 #endif
 874
 875         block = MS_BLOCK_FOR_OBJ (obj);
 876         block->has_pinned = TRUE;
 877         MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 878 }
 879
 880 #include "sgen-major-copy-object.h"
 881
 882 #ifdef SGEN_HAVE_CONCURRENT_MARK
 883 static void
 884 major_copy_or_mark_object_concurrent (void **ptr, void *obj, SgenGrayQueue *queue)
 885 {
 886         SGEN_ASSERT (9, sgen_concurrent_collection_in_progress (), "Why are we scanning concurrently when there's no concurrent collection on?");
 887         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!");
 888
 889         g_assert (!SGEN_OBJECT_IS_FORWARDED (obj));
 890
 891         if (!sgen_ptr_in_nursery (obj)) {
 892                 mword objsize;
 893
 894                 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
 895
 896                 if (objsize <= SGEN_MAX_SMALL_OBJ_SIZE) {
 897                         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
 898                         MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 899                 } else {
 900                         if (sgen_los_object_is_pinned (obj))
 901                                 return;
 902
 903 #ifdef ENABLE_DTRACE
 904                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
 905                                 MonoVTable *vt = (MonoVTable*)SGEN_LOAD_VTABLE (obj);
 906                                 MONO_GC_OBJ_PINNED ((mword)obj, sgen_safe_object_get_size (obj), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
 907                         }
 908 #endif
 909
 910                         sgen_los_pin_object (obj);
 911                         if (SGEN_OBJECT_HAS_REFERENCES (obj))
 912                                 GRAY_OBJECT_ENQUEUE (queue, obj, sgen_obj_get_descriptor (obj));
 913                         INC_NUM_MAJOR_OBJECTS_MARKED ();
 914                 }
 915         }
 916 }
 917 #endif
 918
 919 static void
 920 major_copy_or_mark_object (void **ptr, void *obj, SgenGrayQueue *queue)
 921 {
 922         MSBlockInfo *block;
 923
 924         HEAVY_STAT (++stat_copy_object_called_major);
 925
 926         SGEN_ASSERT (9, !sgen_concurrent_collection_in_progress (), "Why are we scanning non-concurrently when there's a concurrent collection on?");
 927
 928         SGEN_ASSERT (9, obj, "null object from pointer %p", ptr);
 929         SGEN_ASSERT (9, current_collection_generation == GENERATION_OLD, "old gen parallel allocator called from a %d collection", current_collection_generation);
 930
 931         if (sgen_ptr_in_nursery (obj)) {
 932                 int word, bit;
 933                 char *forwarded, *old_obj;
 934
 935                 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 936                         SGEN_UPDATE_REFERENCE (ptr, forwarded);
 937                         return;
 938                 }
 939                 if (SGEN_OBJECT_IS_PINNED (obj))
 940                         return;
 941
 942                 /* An object in the nursery To Space has already been copied and grayed. Nothing to do. */
 943                 if (sgen_nursery_is_to_space (obj))
 944                         return;
 945
 946                 HEAVY_STAT (++stat_objects_copied_major);
 947
 948         do_copy_object:
 949                 old_obj = obj;
 950                 obj = copy_object_no_checks (obj, queue);
 951                 if (G_UNLIKELY (old_obj == obj)) {
 952                         /*If we fail to evacuate an object we just stop doing it for a given block size as all other will surely fail too.*/
 953                         if (!sgen_ptr_in_nursery (obj)) {
 954                                 int size_index;
 955                                 block = MS_BLOCK_FOR_OBJ (obj);
 956                                 size_index = block->obj_size_index;
 957                                 evacuate_block_obj_sizes [size_index] = FALSE;
 958                                 MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 959                         }
 960                         return;
 961                 }
 962                 SGEN_UPDATE_REFERENCE (ptr, obj);
 963
 964                 /*
 965                  * FIXME: See comment for copy_object_no_checks().  If
 966                  * we have that, we can let the allocation function
 967                  * give us the block info, too, and we won't have to
 968                  * re-fetch it.
 969                  *
 970                  * FIXME (2): We should rework this to avoid all those nursery checks.
 971                  */
 972                 /*
 973                  * For the split nursery allocator the object might
 974                  * still be in the nursery despite having being
 975                  * promoted, in which case we can't mark it.
 976                  */
 977                 if (!sgen_ptr_in_nursery (obj)) {
 978                         block = MS_BLOCK_FOR_OBJ (obj);
 979                         MS_CALC_MARK_BIT (word, bit, obj);
 980                         SGEN_ASSERT (9, !MS_MARK_BIT (block, word, bit), "object %p already marked", obj);
 981                         if (!SGEN_VTABLE_HAS_REFERENCES (LOAD_VTABLE (obj))) {
 982                                 MS_SET_MARK_BIT (block, word, bit);
 983                                 binary_protocol_mark (obj, (gpointer)LOAD_VTABLE (obj), sgen_safe_object_get_size ((MonoObject*)obj));
 984                         }
 985                 }
 986         } else {
 987                 char *forwarded;
 988                 mword objsize;
 989
 990                 /*
 991                  * If we have don't have a fixed heap we cannot know
 992                  * whether an object is in the LOS or in the small
 993                  * object major heap without checking its size.  To do
 994                  * that, however, we need to know that we actually
 995                  * have a valid object, not a forwarding pointer, so
 996                  * we have to do this check first.
 997                  */
 998                 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 999                         SGEN_UPDATE_REFERENCE (ptr, forwarded);
1000                         return;
1001                 }
1002
1003                 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
1004
1005                 if (objsize <= SGEN_MAX_SMALL_OBJ_SIZE) {
1006                         int size_index;
1007                         gboolean evacuate;
1008
1009                         block = MS_BLOCK_FOR_OBJ (obj);
1010                         size_index = block->obj_size_index;
1011                         evacuate = evacuate_block_obj_sizes [size_index];
1012
1013                         if (evacuate && !block->has_pinned) {
1014                                 g_assert (!SGEN_OBJECT_IS_PINNED (obj));
1015                                 if (block->is_to_space)
1016                                         return;
1017                                 HEAVY_STAT (++stat_major_objects_evacuated);
1018                                 goto do_copy_object;
1019                         } else {
1020                                 MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
1021                         }
1022                 } else {
1023                         if (sgen_los_object_is_pinned (obj))
1024                                 return;
1025                         binary_protocol_pin (obj, (gpointer)SGEN_LOAD_VTABLE (obj), sgen_safe_object_get_size ((MonoObject*)obj));
1026
1027 #ifdef ENABLE_DTRACE
1028                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1029                                 MonoVTable *vt = (MonoVTable*)SGEN_LOAD_VTABLE (obj);
1030                                 MONO_GC_OBJ_PINNED ((mword)obj, sgen_safe_object_get_size (obj), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
1031                         }
1032 #endif
1033
1034                         if (SGEN_OBJECT_HAS_REFERENCES (obj))
1035                                 GRAY_OBJECT_ENQUEUE (queue, obj, sgen_obj_get_descriptor (obj));
1036                 }
1037         }
1038 }
1039
1040 static void
1041 major_copy_or_mark_object_canonical (void **ptr, SgenGrayQueue *queue)
1042 {
1043         major_copy_or_mark_object (ptr, *ptr, queue);
1044 }
1045
1046 #ifdef SGEN_HAVE_CONCURRENT_MARK
1047 static void
1048 major_copy_or_mark_object_concurrent_canonical (void **ptr, SgenGrayQueue *queue)
1049 {
1050         major_copy_or_mark_object_concurrent (ptr, *ptr, queue);
1051 }
1052 #endif
1053
1054 static long long
1055 major_get_and_reset_num_major_objects_marked (void)
1056 {
1057 #ifdef SGEN_COUNT_NUMBER_OF_MAJOR_OBJECTS_MARKED
1058         long long num = num_major_objects_marked;
1059         num_major_objects_marked = 0;
1060         return num;
1061 #else
1062         return 0;
1063 #endif
1064 }
1065
1066 #include "sgen-major-scan-object.h"
1067
1068 #ifdef SGEN_HAVE_CONCURRENT_MARK
1069 #define SCAN_FOR_CONCURRENT_MARK
1070 #include "sgen-major-scan-object.h"
1071 #undef SCAN_FOR_CONCURRENT_MARK
1072 #endif
1073
1074 #if !defined (FIXED_HEAP) && !defined (SGEN_PARALLEL_MARK)
1075 //#define USE_PREFETCH_QUEUE
1076
1077 #ifdef HEAVY_STATISTICS
1078 static long long stat_optimized_copy_object_called;
1079 static long long stat_optimized_nursery;
1080 static long long stat_optimized_nursery_forwarded;
1081 static long long stat_optimized_nursery_pinned;
1082 static long long stat_optimized_major_mark;
1083 static long long stat_optimized_major_mark_small;
1084 static long long stat_optimized_major_mark_large;
1085 static long long stat_optimized_major_scan;
1086 static long long stat_optimized_major_scan_fast;
1087 static long long stat_optimized_major_scan_slow;
1088
1089 static long long stat_drain_prefetch_fills;
1090 static long long stat_drain_prefetch_fill_failures;
1091 static long long stat_drain_loops;
1092 #endif
1093
1094 /* Returns whether the object is still in the nursery. */
1095 static gboolean
1096 optimized_copy_or_mark_object (void **ptr, void *obj, SgenGrayQueue *queue)
1097 {
1098         HEAVY_STAT (++stat_optimized_copy_object_called);
1099
1100         SGEN_ASSERT (9, obj, "null object from pointer %p", ptr);
1101         SGEN_ASSERT (9, current_collection_generation == GENERATION_OLD, "old gen parallel allocator called from a %d collection", current_collection_generation);
1102
1103         if (sgen_ptr_in_nursery (obj)) {
1104                 mword vtable_word = *(mword*)obj;
1105                 char *forwarded, *old_obj;
1106
1107                 HEAVY_STAT (++stat_optimized_nursery);
1108
1109                 if (SGEN_VTABLE_IS_PINNED (vtable_word)) {
1110                         HEAVY_STAT (++stat_optimized_nursery_pinned);
1111                         return TRUE;
1112                 }
1113                 if ((forwarded = SGEN_VTABLE_IS_FORWARDED (vtable_word))) {
1114                         HEAVY_STAT (++stat_optimized_nursery_forwarded);
1115                         *ptr = forwarded;
1116                         return FALSE;
1117                 }
1118
1119                 old_obj = obj;
1120                 obj = copy_object_no_checks (obj, queue);
1121                 SGEN_ASSERT (0, old_obj != obj, "Cannot handle copy object failure.");
1122                 HEAVY_STAT (++stat_objects_copied_major);
1123                 *ptr = obj;
1124                 return FALSE;
1125         } else {
1126                 GRAY_OBJECT_ENQUEUE (queue, obj, 0);
1127         }
1128         return FALSE;
1129 }
1130
1131 static gboolean
1132 drain_gray_stack (ScanCopyContext ctx)
1133 {
1134         SgenGrayQueue *queue = ctx.queue;
1135
1136         SGEN_ASSERT (0, ctx.scan_func == major_scan_object, "Wrong scan function");
1137
1138 #ifdef USE_PREFETCH_QUEUE
1139         HEAVY_STAT (++stat_drain_prefetch_fills);
1140         if (!sgen_gray_object_fill_prefetch (queue)) {
1141                 HEAVY_STAT (++stat_drain_prefetch_fill_failures);
1142                 return TRUE;
1143         }
1144 #endif
1145
1146         for (;;) {
1147                 char *obj;
1148                 mword desc;
1149                 int type;
1150
1151                 HEAVY_STAT (++stat_drain_loops);
1152
1153 #ifdef USE_PREFETCH_QUEUE
1154                 sgen_gray_object_dequeue_fast (queue, &obj, &desc);
1155                 if (!obj) {
1156                         HEAVY_STAT (++stat_drain_prefetch_fills);
1157                         if (!sgen_gray_object_fill_prefetch (queue)) {
1158                                 HEAVY_STAT (++stat_drain_prefetch_fill_failures);
1159                                 return TRUE;
1160                         }
1161                         continue;
1162                 }
1163 #else
1164                 GRAY_OBJECT_DEQUEUE (queue, &obj, &desc);
1165                 if (!obj)
1166                         return TRUE;
1167 #endif
1168
1169                 desc = sgen_obj_get_descriptor_safe (obj);
1170                 type = desc & 7;
1171
1172                 HEAVY_STAT (++stat_optimized_major_mark);
1173
1174                 /* Mark object or, if already marked, don't process. */
1175                 if (!sgen_ptr_in_nursery (obj)) {
1176                         if (type == DESC_TYPE_SMALL_BITMAP || SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj)) <= SGEN_MAX_SMALL_OBJ_SIZE) {
1177                                 MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
1178                                 int __word, __bit;
1179
1180                                 HEAVY_STAT (++stat_optimized_major_mark_small);
1181
1182                                 MS_CALC_MARK_BIT (__word, __bit, (obj));
1183                                 if (MS_MARK_BIT ((block), __word, __bit))
1184                                         continue;
1185                                 MS_SET_MARK_BIT ((block), __word, __bit);
1186                         } else {
1187                                 HEAVY_STAT (++stat_optimized_major_mark_large);
1188
1189                                 if (sgen_los_object_is_pinned (obj))
1190                                         continue;
1191                                 sgen_los_pin_object (obj);
1192                         }
1193                 }
1194
1195                 HEAVY_STAT (++stat_optimized_major_scan);
1196
1197                 /* Now scan the object. */
1198 #ifdef HEAVY_STATISTICS
1199                 sgen_descriptor_count_scanned_object (desc);
1200 #endif
1201                 if (type == DESC_TYPE_SMALL_BITMAP) {
1202                         void **_objptr = (void**)(obj);
1203                         gsize _bmap = (desc) >> 16;
1204                         _objptr += OBJECT_HEADER_WORDS;
1205                         do {
1206                                 int _index = GNUC_BUILTIN_CTZ (_bmap);
1207                                 _objptr += _index;
1208                                 _bmap >>= (_index + 1);
1209
1210                                 void *__old = *(_objptr);
1211                                 if (__old) {
1212                                         gboolean still_in_nursery = optimized_copy_or_mark_object (_objptr, __old, queue);
1213                                         if (G_UNLIKELY (still_in_nursery && !sgen_ptr_in_nursery ((_objptr)))) {
1214                                                 void *__copy = *(_objptr);
1215                                                 sgen_add_to_global_remset ((_objptr), __copy);
1216                                         }
1217                                 }
1218
1219                                 _objptr ++;
1220                         } while (_bmap);
1221 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
1222                         add_scanned_object (obj);
1223                         ++stat_optimized_major_scan_slow;
1224 #endif
1225                 } else {
1226                         HEAVY_STAT (++stat_optimized_major_scan_fast);
1227                         major_scan_object_no_mark (obj, desc, queue);
1228                 }
1229         }
1230 }
1231 #endif
1232
1233 static void
1234 mark_pinned_objects_in_block (MSBlockInfo *block, SgenGrayQueue *queue)
1235 {
1236         void **entry, **end;
1237         int last_index = -1;
1238
1239         if (block->pin_queue_first_entry == block->pin_queue_last_entry)
1240                 return;
1241
1242         block->has_pinned = TRUE;
1243
1244         entry = sgen_pinning_get_entry (block->pin_queue_first_entry);
1245         end = sgen_pinning_get_entry (block->pin_queue_last_entry);
1246
1247         for (; entry < end; ++entry) {
1248                 int index = MS_BLOCK_OBJ_INDEX (*entry, block);
1249                 char *obj;
1250                 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);
1251                 if (index == last_index)
1252                         continue;
1253                 obj = MS_BLOCK_OBJ (block, index);
1254                 MS_MARK_OBJECT_AND_ENQUEUE_CHECKED (obj, sgen_obj_get_descriptor (obj), block, queue);
1255                 last_index = index;
1256         }
1257 }
1258
1259 static inline void
1260 sweep_block_for_size (MSBlockInfo *block, int count, int obj_size)
1261 {
1262         int obj_index;
1263
1264         for (obj_index = 0; obj_index < count; ++obj_index) {
1265                 int word, bit;
1266                 void *obj = MS_BLOCK_OBJ_FOR_SIZE (block, obj_index, obj_size);
1267
1268                 MS_CALC_MARK_BIT (word, bit, obj);
1269                 if (MS_MARK_BIT (block, word, bit)) {
1270                         SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p not allocated", obj);
1271                 } else {
1272                         /* an unmarked object */
1273                         if (MS_OBJ_ALLOCED (obj, block)) {
1274                                 /*
1275                                  * FIXME: Merge consecutive
1276                                  * slots for lower reporting
1277                                  * overhead.  Maybe memset
1278                                  * will also benefit?
1279                                  */
1280                                 binary_protocol_empty (obj, obj_size);
1281                                 MONO_GC_MAJOR_SWEPT ((mword)obj, obj_size);
1282                                 memset (obj, 0, obj_size);
1283                         }
1284                         *(void**)obj = block->free_list;
1285                         block->free_list = obj;
1286                 }
1287         }
1288 }
1289
1290 /*
1291  * sweep_block:
1292  *
1293  *   Traverse BLOCK, freeing and zeroing unused objects.
1294  */
1295 static void
1296 sweep_block (MSBlockInfo *block, gboolean during_major_collection)
1297 {
1298         int count;
1299         void *reversed = NULL;
1300
1301         if (!during_major_collection)
1302                 g_assert (!sgen_concurrent_collection_in_progress ());
1303
1304         if (block->swept)
1305                 return;
1306
1307         count = MS_BLOCK_FREE / block->obj_size;
1308
1309         block->free_list = NULL;
1310
1311         /* Use inline instances specialized to constant sizes, this allows the compiler to replace the memset calls with inline code */
1312         // FIXME: Add more sizes
1313         switch (block->obj_size) {
1314         case 16:
1315                 sweep_block_for_size (block, count, 16);
1316                 break;
1317         default:
1318                 sweep_block_for_size (block, count, block->obj_size);
1319                 break;
1320         }
1321
1322         /* reset mark bits */
1323         memset (block->mark_words, 0, sizeof (mword) * MS_NUM_MARK_WORDS);
1324
1325         /* Reverse free list so that it's in address order */
1326         reversed = NULL;
1327         while (block->free_list) {
1328                 void *next = *(void**)block->free_list;
1329                 *(void**)block->free_list = reversed;
1330                 reversed = block->free_list;
1331                 block->free_list = next;
1332         }
1333         block->free_list = reversed;
1334
1335         block->swept = 1;
1336 }
1337
1338 static inline int
1339 bitcount (mword d)
1340 {
1341         int count = 0;
1342
1343 #ifdef __GNUC__
1344         if (sizeof (mword) == sizeof (unsigned long))
1345                 count += __builtin_popcountl (d);
1346         else
1347                 count += __builtin_popcount (d);
1348 #else
1349         while (d) {
1350                 count ++;
1351                 d &= (d - 1);
1352         }
1353 #endif
1354         return count;
1355 }
1356
1357 static void
1358 ms_sweep (void)
1359 {
1360         int i;
1361         MSBlockInfo *block;
1362
1363         /* statistics for evacuation */
1364         int *slots_available = alloca (sizeof (int) * num_block_obj_sizes);
1365         int *slots_used = alloca (sizeof (int) * num_block_obj_sizes);
1366         int *num_blocks = alloca (sizeof (int) * num_block_obj_sizes);
1367
1368 #ifdef SGEN_HAVE_CONCURRENT_MARK
1369         mword total_evacuate_heap = 0;
1370         mword total_evacuate_saved = 0;
1371 #endif
1372
1373         for (i = 0; i < num_block_obj_sizes; ++i)
1374                 slots_available [i] = slots_used [i] = num_blocks [i] = 0;
1375
1376         /* clear all the free lists */
1377         for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i) {
1378                 MSBlockInfo **free_blocks = free_block_lists [i];
1379                 int j;
1380                 for (j = 0; j < num_block_obj_sizes; ++j)
1381                         free_blocks [j] = NULL;
1382         }
1383
1384         /* traverse all blocks, free and zero unmarked objects */
1385         FOREACH_BLOCK (block) {
1386                 int count;
1387                 gboolean have_live = FALSE;
1388                 gboolean has_pinned;
1389                 gboolean have_free = FALSE;
1390                 int obj_size_index;
1391                 int nused = 0;
1392
1393                 obj_size_index = block->obj_size_index;
1394
1395                 has_pinned = block->has_pinned;
1396                 block->has_pinned = block->pinned;
1397
1398                 block->is_to_space = FALSE;
1399                 block->swept = 0;
1400
1401                 count = MS_BLOCK_FREE / block->obj_size;
1402
1403 #ifdef SGEN_HAVE_CONCURRENT_MARK
1404                 if (block->cardtable_mod_union) {
1405                         sgen_free_internal_dynamic (block->cardtable_mod_union, CARDS_PER_BLOCK, INTERNAL_MEM_CARDTABLE_MOD_UNION);
1406                         block->cardtable_mod_union = NULL;
1407                 }
1408 #endif
1409
1410                 /* Count marked objects in the block */
1411                 for (i = 0; i < MS_NUM_MARK_WORDS; ++i) {
1412                         nused += bitcount (block->mark_words [i]);
1413                 }
1414                 if (nused) {
1415                         have_live = TRUE;
1416                 }
1417                 if (nused < count)
1418                         have_free = TRUE;
1419
1420                 if (!lazy_sweep)
1421                         sweep_block (block, TRUE);
1422
1423                 if (have_live) {
1424                         if (!has_pinned) {
1425                                 ++num_blocks [obj_size_index];
1426                                 slots_used [obj_size_index] += nused;
1427                                 slots_available [obj_size_index] += count;
1428                         }
1429
1430                         /*
1431                          * If there are free slots in the block, add
1432                          * the block to the corresponding free list.
1433                          */
1434                         if (have_free) {
1435                                 MSBlockInfo **free_blocks = FREE_BLOCKS (block->pinned, block->has_references);
1436                                 int index = MS_BLOCK_OBJ_SIZE_INDEX (block->obj_size);
1437                                 block->next_free = free_blocks [index];
1438                                 free_blocks [index] = block;
1439                         }
1440
1441                         update_heap_boundaries_for_block (block);
1442                 } else {
1443                         /*
1444                          * Blocks without live objects are removed from the
1445                          * block list and freed.
1446                          */
1447                         DELETE_BLOCK_IN_FOREACH ();
1448
1449                         binary_protocol_empty (MS_BLOCK_OBJ (block, 0), (char*)MS_BLOCK_OBJ (block, count) - (char*)MS_BLOCK_OBJ (block, 0));
1450                         ms_free_block (block->block);
1451                         sgen_free_internal (block, INTERNAL_MEM_MS_BLOCK_INFO);
1452
1453                         --num_major_sections;
1454                 }
1455         } END_FOREACH_BLOCK;
1456         sgen_pointer_queue_remove_nulls (&allocated_blocks);
1457
1458         for (i = 0; i < num_block_obj_sizes; ++i) {
1459                 float usage = (float)slots_used [i] / (float)slots_available [i];
1460                 if (num_blocks [i] > 5 && usage < evacuation_threshold) {
1461                         g_assert_not_reached ();
1462                         evacuate_block_obj_sizes [i] = TRUE;
1463                         /*
1464                         g_print ("slot size %d - %d of %d used\n",
1465                                         block_obj_sizes [i], slots_used [i], slots_available [i]);
1466                         */
1467                 } else {
1468                         evacuate_block_obj_sizes [i] = FALSE;
1469                 }
1470 #ifdef SGEN_HAVE_CONCURRENT_MARK
1471                 {
1472                         mword total_bytes = block_obj_sizes [i] * slots_available [i];
1473                         total_evacuate_heap += total_bytes;
1474                         if (evacuate_block_obj_sizes [i])
1475                                 total_evacuate_saved += total_bytes - block_obj_sizes [i] * slots_used [i];
1476                 }
1477 #endif
1478         }
1479
1480 #ifdef SGEN_HAVE_CONCURRENT_MARK
1481         want_evacuation = (float)total_evacuate_saved / (float)total_evacuate_heap > (1 - concurrent_evacuation_threshold);
1482 #endif
1483
1484         have_swept = TRUE;
1485 }
1486
1487 static void
1488 major_sweep (void)
1489 {
1490         ms_sweep ();
1491 }
1492
1493 static int count_pinned_ref;
1494 static int count_pinned_nonref;
1495 static int count_nonpinned_ref;
1496 static int count_nonpinned_nonref;
1497
1498 static void
1499 count_nonpinned_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_nonpinned_ref;
1505         else
1506                 ++count_nonpinned_nonref;
1507 }
1508
1509 static void
1510 count_pinned_callback (char *obj, size_t size, void *data)
1511 {
1512         MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
1513
1514         if (vtable->klass->has_references)
1515                 ++count_pinned_ref;
1516         else
1517                 ++count_pinned_nonref;
1518 }
1519
1520 static G_GNUC_UNUSED void
1521 count_ref_nonref_objs (void)
1522 {
1523         int total;
1524
1525         count_pinned_ref = 0;
1526         count_pinned_nonref = 0;
1527         count_nonpinned_ref = 0;
1528         count_nonpinned_nonref = 0;
1529
1530         major_iterate_objects (ITERATE_OBJECTS_SWEEP_NON_PINNED, count_nonpinned_callback, NULL);
1531         major_iterate_objects (ITERATE_OBJECTS_SWEEP_PINNED, count_pinned_callback, NULL);
1532
1533         total = count_pinned_nonref + count_nonpinned_nonref + count_pinned_ref + count_nonpinned_ref;
1534
1535         g_print ("ref: %d pinned %d non-pinned   non-ref: %d pinned %d non-pinned  --  %.1f\n",
1536                         count_pinned_ref, count_nonpinned_ref,
1537                         count_pinned_nonref, count_nonpinned_nonref,
1538                         (count_pinned_nonref + count_nonpinned_nonref) * 100.0 / total);
1539 }
1540
1541 static int
1542 ms_calculate_block_obj_sizes (double factor, int *arr)
1543 {
1544         double target_size = sizeof (MonoObject);
1545         int num_sizes = 0;
1546         int last_size = 0;
1547
1548         do {
1549                 int target_count = (int)ceil (MS_BLOCK_FREE / target_size);
1550                 int size = MIN ((MS_BLOCK_FREE / target_count) & ~(SGEN_ALLOC_ALIGN - 1), SGEN_MAX_SMALL_OBJ_SIZE);
1551
1552                 if (size != last_size) {
1553                         if (arr)
1554                                 arr [num_sizes] = size;
1555                         ++num_sizes;
1556                         last_size = size;
1557                 }
1558
1559                 target_size *= factor;
1560         } while (last_size < SGEN_MAX_SMALL_OBJ_SIZE);
1561
1562         return num_sizes;
1563 }
1564
1565 /* only valid during minor collections */
1566 static mword old_num_major_sections;
1567
1568 static void
1569 major_start_nursery_collection (void)
1570 {
1571 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1572         consistency_check ();
1573 #endif
1574
1575         old_num_major_sections = num_major_sections;
1576 }
1577
1578 static void
1579 major_finish_nursery_collection (void)
1580 {
1581 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1582         consistency_check ();
1583 #endif
1584         sgen_register_major_sections_alloced (num_major_sections - old_num_major_sections);
1585 }
1586
1587 static void
1588 major_start_major_collection (void)
1589 {
1590         int i;
1591
1592         /* clear the free lists */
1593         for (i = 0; i < num_block_obj_sizes; ++i) {
1594                 if (!evacuate_block_obj_sizes [i])
1595                         continue;
1596
1597                 free_block_lists [0][i] = NULL;
1598                 free_block_lists [MS_BLOCK_FLAG_REFS][i] = NULL;
1599         }
1600
1601         // Sweep all unswept blocks
1602         if (lazy_sweep) {
1603                 MSBlockInfo *block;
1604
1605                 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, TRUE);
1606
1607                 FOREACH_BLOCK (block) {
1608                         sweep_block (block, TRUE);
1609                 } END_FOREACH_BLOCK;
1610
1611                 MONO_GC_SWEEP_END (GENERATION_OLD, TRUE);
1612         }
1613 }
1614
1615 static void
1616 major_finish_major_collection (ScannedObjectCounts *counts)
1617 {
1618 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
1619         if (binary_protocol_is_enabled ()) {
1620                 counts->num_scanned_objects = scanned_objects_list.next_slot;
1621
1622                 sgen_pointer_queue_sort_uniq (&scanned_objects_list);
1623                 counts->num_unique_scanned_objects = scanned_objects_list.next_slot;
1624
1625                 sgen_pointer_queue_clear (&scanned_objects_list);
1626         }
1627 #endif
1628 }
1629
1630 #if SIZEOF_VOID_P != 8
1631 static int
1632 compare_pointers (const void *va, const void *vb) {
1633         char *a = *(char**)va, *b = *(char**)vb;
1634         if (a < b)
1635                 return -1;
1636         if (a > b)
1637                 return 1;
1638         return 0;
1639 }
1640 #endif
1641
1642 static void
1643 major_have_computer_minor_collection_allowance (void)
1644 {
1645         size_t section_reserve = sgen_get_minor_collection_allowance () / MS_BLOCK_SIZE;
1646
1647         g_assert (have_swept);
1648
1649 #if SIZEOF_VOID_P != 8
1650         {
1651                 int i, num_empty_blocks_orig, num_blocks, arr_length;
1652                 void *block;
1653                 void **empty_block_arr;
1654                 void **rebuild_next;
1655
1656 #ifdef TARGET_WIN32
1657                 /*
1658                  * sgen_free_os_memory () asserts in mono_vfree () because windows doesn't like freeing the middle of
1659                  * a VirtualAlloc ()-ed block.
1660                  */
1661                 return;
1662 #endif
1663
1664                 if (num_empty_blocks <= section_reserve)
1665                         return;
1666                 SGEN_ASSERT (0, num_empty_blocks > 0, "section reserve can't be negative");
1667
1668                 num_empty_blocks_orig = num_empty_blocks;
1669                 empty_block_arr = (void**)sgen_alloc_internal_dynamic (sizeof (void*) * num_empty_blocks_orig,
1670                                 INTERNAL_MEM_MS_BLOCK_INFO_SORT, FALSE);
1671                 if (!empty_block_arr)
1672                         goto fallback;
1673
1674                 i = 0;
1675                 for (block = empty_blocks; block; block = *(void**)block)
1676                         empty_block_arr [i++] = block;
1677                 SGEN_ASSERT (0, i == num_empty_blocks, "empty block count wrong");
1678
1679                 sgen_qsort (empty_block_arr, num_empty_blocks, sizeof (void*), compare_pointers);
1680
1681                 /*
1682                  * We iterate over the free blocks, trying to find MS_BLOCK_ALLOC_NUM
1683                  * contiguous ones.  If we do, we free them.  If that's not enough to get to
1684                  * section_reserve, we halve the number of contiguous blocks we're looking
1685                  * for and have another go, until we're done with looking for pairs of
1686                  * blocks, at which point we give up and go to the fallback.
1687                  */
1688                 arr_length = num_empty_blocks_orig;
1689                 num_blocks = MS_BLOCK_ALLOC_NUM;
1690                 while (num_empty_blocks > section_reserve && num_blocks > 1) {
1691                         int first = -1;
1692                         int dest = 0;
1693
1694                         dest = 0;
1695                         for (i = 0; i < arr_length; ++i) {
1696                                 int d = dest;
1697                                 void *block = empty_block_arr [i];
1698                                 SGEN_ASSERT (0, block, "we're not shifting correctly");
1699                                 if (i != dest) {
1700                                         empty_block_arr [dest] = block;
1701                                         /*
1702                                          * This is not strictly necessary, but we're
1703                                          * cautious.
1704                                          */
1705                                         empty_block_arr [i] = NULL;
1706                                 }
1707                                 ++dest;
1708
1709                                 if (first < 0) {
1710                                         first = d;
1711                                         continue;
1712                                 }
1713
1714                                 SGEN_ASSERT (0, first >= 0 && d > first, "algorithm is wrong");
1715
1716                                 if ((char*)block != ((char*)empty_block_arr [d-1]) + MS_BLOCK_SIZE) {
1717                                         first = d;
1718                                         continue;
1719                                 }
1720
1721                                 if (d + 1 - first == num_blocks) {
1722                                         /*
1723                                          * We found num_blocks contiguous blocks.  Free them
1724                                          * and null their array entries.  As an optimization
1725                                          * we could, instead of nulling the entries, shift
1726                                          * the following entries over to the left, while
1727                                          * we're iterating.
1728                                          */
1729                                         int j;
1730                                         sgen_free_os_memory (empty_block_arr [first], MS_BLOCK_SIZE * num_blocks, SGEN_ALLOC_HEAP);
1731                                         for (j = first; j <= d; ++j)
1732                                                 empty_block_arr [j] = NULL;
1733                                         dest = first;
1734                                         first = -1;
1735
1736                                         num_empty_blocks -= num_blocks;
1737
1738                                         stat_major_blocks_freed += num_blocks;
1739                                         if (num_blocks == MS_BLOCK_ALLOC_NUM)
1740                                                 stat_major_blocks_freed_ideal += num_blocks;
1741                                         else
1742                                                 stat_major_blocks_freed_less_ideal += num_blocks;
1743
1744                                 }
1745                         }
1746
1747                         SGEN_ASSERT (0, dest <= i && dest <= arr_length, "array length is off");
1748                         arr_length = dest;
1749                         SGEN_ASSERT (0, arr_length == num_empty_blocks, "array length is off");
1750
1751                         num_blocks >>= 1;
1752                 }
1753
1754                 /* rebuild empty_blocks free list */
1755                 rebuild_next = (void**)&empty_blocks;
1756                 for (i = 0; i < arr_length; ++i) {
1757                         void *block = empty_block_arr [i];
1758                         SGEN_ASSERT (0, block, "we're missing blocks");
1759                         *rebuild_next = block;
1760                         rebuild_next = (void**)block;
1761                 }
1762                 *rebuild_next = NULL;
1763
1764                 /* free array */
1765                 sgen_free_internal_dynamic (empty_block_arr, sizeof (void*) * num_empty_blocks_orig, INTERNAL_MEM_MS_BLOCK_INFO_SORT);
1766         }
1767
1768         SGEN_ASSERT (0, num_empty_blocks >= 0, "we freed more blocks than we had in the first place?");
1769
1770  fallback:
1771         /*
1772          * This is our threshold.  If there's not more empty than used blocks, we won't
1773          * release uncontiguous blocks, in fear of fragmenting the address space.
1774          */
1775         if (num_empty_blocks <= num_major_sections)
1776                 return;
1777 #endif
1778
1779         while (num_empty_blocks > section_reserve) {
1780                 void *next = *(void**)empty_blocks;
1781                 sgen_free_os_memory (empty_blocks, MS_BLOCK_SIZE, SGEN_ALLOC_HEAP);
1782                 empty_blocks = next;
1783                 /*
1784                  * Needs not be atomic because this is running
1785                  * single-threaded.
1786                  */
1787                 --num_empty_blocks;
1788
1789                 ++stat_major_blocks_freed;
1790 #if SIZEOF_VOID_P != 8
1791                 ++stat_major_blocks_freed_individual;
1792 #endif
1793         }
1794 }
1795
1796 static void
1797 major_find_pin_queue_start_ends (SgenGrayQueue *queue)
1798 {
1799         MSBlockInfo *block;
1800
1801         FOREACH_BLOCK (block) {
1802                 sgen_find_optimized_pin_queue_area (MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SKIP, MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE,
1803                                 &block->pin_queue_first_entry, &block->pin_queue_last_entry);
1804         } END_FOREACH_BLOCK;
1805 }
1806
1807 static void
1808 major_pin_objects (SgenGrayQueue *queue)
1809 {
1810         MSBlockInfo *block;
1811
1812         FOREACH_BLOCK (block) {
1813                 mark_pinned_objects_in_block (block, queue);
1814         } END_FOREACH_BLOCK;
1815 }
1816
1817 static void
1818 major_init_to_space (void)
1819 {
1820 }
1821
1822 static void
1823 major_report_pinned_memory_usage (void)
1824 {
1825         g_assert_not_reached ();
1826 }
1827
1828 static gint64
1829 major_get_used_size (void)
1830 {
1831         gint64 size = 0;
1832         MSBlockInfo *block;
1833
1834         FOREACH_BLOCK (block) {
1835                 int count = MS_BLOCK_FREE / block->obj_size;
1836                 void **iter;
1837                 size += count * block->obj_size;
1838                 for (iter = block->free_list; iter; iter = (void**)*iter)
1839                         size -= block->obj_size;
1840         } END_FOREACH_BLOCK;
1841
1842         return size;
1843 }
1844
1845 static size_t
1846 get_num_major_sections (void)
1847 {
1848         return num_major_sections;
1849 }
1850
1851 static gboolean
1852 major_handle_gc_param (const char *opt)
1853 {
1854         /*
1855         if (g_str_has_prefix (opt, "evacuation-threshold=")) {
1856                 const char *arg = strchr (opt, '=') + 1;
1857                 int percentage = atoi (arg);
1858                 if (percentage < 0 || percentage > 100) {
1859                         fprintf (stderr, "evacuation-threshold must be an integer in the range 0-100.\n");
1860                         exit (1);
1861                 }
1862                 evacuation_threshold = (float)percentage / 100.0f;
1863                 return TRUE;
1864                 } else */
1865         if (!strcmp (opt, "lazy-sweep")) {
1866                 lazy_sweep = TRUE;
1867                 return TRUE;
1868         } else if (!strcmp (opt, "no-lazy-sweep")) {
1869                 lazy_sweep = FALSE;
1870                 return TRUE;
1871         }
1872
1873         return FALSE;
1874 }
1875
1876 static void
1877 major_print_gc_param_usage (void)
1878 {
1879         fprintf (stderr,
1880                         ""
1881                         "  evacuation-threshold=P (where P is a percentage, an integer in 0-100)\n"
1882                         "  (no-)lazy-sweep\n"
1883                         );
1884 }
1885
1886 static void
1887 major_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
1888 {
1889         MSBlockInfo *block;
1890         gboolean has_references;
1891
1892         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1893                 if (has_references)
1894                         callback ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE);
1895         } END_FOREACH_BLOCK;
1896 }
1897
1898 #ifdef HEAVY_STATISTICS
1899 extern long long marked_cards;
1900 extern long long scanned_cards;
1901 extern long long scanned_objects;
1902 extern long long remarked_cards;
1903 #endif
1904
1905 #define CARD_WORDS_PER_BLOCK (CARDS_PER_BLOCK / SIZEOF_VOID_P)
1906 /*
1907  * MS blocks are 16K aligned.
1908  * Cardtables are 4K aligned, at least.
1909  * This means that the cardtable of a given block is 32 bytes aligned.
1910  */
1911 static guint8*
1912 initial_skip_card (guint8 *card_data)
1913 {
1914         mword *cards = (mword*)card_data;
1915         mword card;
1916         int i;
1917         for (i = 0; i < CARD_WORDS_PER_BLOCK; ++i) {
1918                 card = cards [i];
1919                 if (card)
1920                         break;
1921         }
1922
1923         if (i == CARD_WORDS_PER_BLOCK)
1924                 return card_data + CARDS_PER_BLOCK;
1925
1926 #if defined(__i386__) && defined(__GNUC__)
1927         return card_data + i * 4 +  (__builtin_ffs (card) - 1) / 8;
1928 #elif defined(__x86_64__) && defined(__GNUC__)
1929         return card_data + i * 8 +  (__builtin_ffsll (card) - 1) / 8;
1930 #elif defined(__s390x__) && defined(__GNUC__)
1931         return card_data + i * 8 +  (__builtin_ffsll (GUINT64_TO_LE(card)) - 1) / 8;
1932 #else
1933         for (i = i * SIZEOF_VOID_P; i < CARDS_PER_BLOCK; ++i) {
1934                 if (card_data [i])
1935                         return &card_data [i];
1936         }
1937         return card_data;
1938 #endif
1939 }
1940
1941
1942 static G_GNUC_UNUSED guint8*
1943 skip_card (guint8 *card_data, guint8 *card_data_end)
1944 {
1945         while (card_data < card_data_end && !*card_data)
1946                 ++card_data;
1947         return card_data;
1948 }
1949
1950 #define MS_BLOCK_OBJ_INDEX_FAST(o,b,os) (((char*)(o) - ((b) + MS_BLOCK_SKIP)) / (os))
1951 #define MS_BLOCK_OBJ_FAST(b,os,i)                       ((b) + MS_BLOCK_SKIP + (os) * (i))
1952 #define MS_OBJ_ALLOCED_FAST(o,b)                (*(void**)(o) && (*(char**)(o) < (b) || *(char**)(o) >= (b) + MS_BLOCK_SIZE))
1953
1954 static void
1955 major_scan_card_table (gboolean mod_union, SgenGrayQueue *queue)
1956 {
1957         MSBlockInfo *block;
1958         gboolean has_references;
1959         ScanObjectFunc scan_func = sgen_get_current_object_ops ()->scan_object;
1960
1961 #ifdef SGEN_HAVE_CONCURRENT_MARK
1962         if (!concurrent_mark)
1963                 g_assert (!mod_union);
1964 #else
1965         g_assert (!mod_union);
1966 #endif
1967
1968         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1969                 int block_obj_size;
1970                 char *block_start;
1971
1972                 if (!has_references)
1973                         continue;
1974
1975                 block_obj_size = block->obj_size;
1976                 block_start = MS_BLOCK_FOR_BLOCK_INFO (block);
1977
1978                 if (block_obj_size >= CARD_SIZE_IN_BYTES) {
1979                         guint8 *cards;
1980 #ifndef SGEN_HAVE_OVERLAPPING_CARDS
1981                         guint8 cards_data [CARDS_PER_BLOCK];
1982 #endif
1983                         char *obj, *end, *base;
1984
1985                         if (mod_union) {
1986 #ifdef SGEN_HAVE_CONCURRENT_MARK
1987                                 cards = block->cardtable_mod_union;
1988                                 /*
1989                                  * This happens when the nursery
1990                                  * collection that precedes finishing
1991                                  * the concurrent collection allocates
1992                                  * new major blocks.
1993                                  */
1994                                 if (!cards)
1995                                         continue;
1996 #endif
1997                         } else {
1998                         /*We can avoid the extra copy since the remark cardtable was cleaned before */
1999 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
2000                                 cards = sgen_card_table_get_card_scan_address ((mword)block_start);
2001 #else
2002                                 cards = cards_data;
2003                                 if (!sgen_card_table_get_card_data (cards_data, (mword)block_start, CARDS_PER_BLOCK))
2004                                         continue;
2005 #endif
2006                         }
2007
2008                         obj = (char*)MS_BLOCK_OBJ_FAST (block_start, block_obj_size, 0);
2009                         end = block_start + MS_BLOCK_SIZE;
2010                         base = sgen_card_table_align_pointer (obj);
2011
2012                         while (obj < end) {
2013                                 size_t card_offset;
2014
2015                                 if (!block->swept)
2016                                         sweep_block (block, FALSE);
2017
2018                                 if (!MS_OBJ_ALLOCED_FAST (obj, block_start))
2019                                         goto next_large;
2020
2021                                 if (mod_union) {
2022                                         /* FIXME: do this more efficiently */
2023                                         int w, b;
2024                                         MS_CALC_MARK_BIT (w, b, obj);
2025                                         if (!MS_MARK_BIT (block, w, b))
2026                                                 goto next_large;
2027                                 }
2028
2029                                 card_offset = (obj - base) >> CARD_BITS;
2030                                 sgen_cardtable_scan_object (obj, block_obj_size, cards + card_offset, mod_union, queue);
2031
2032                         next_large:
2033                                 obj += block_obj_size;
2034                         }
2035                 } else {
2036                         guint8 *card_data, *card_base;
2037                         guint8 *card_data_end;
2038
2039                         /*
2040                          * This is safe in face of card aliasing for the following reason:
2041                          *
2042                          * Major blocks are 16k aligned, or 32 cards aligned.
2043                          * Cards aliasing happens in powers of two, so as long as major blocks are aligned to their
2044                          * sizes, they won't overflow the cardtable overlap modulus.
2045                          */
2046                         if (mod_union) {
2047 #ifdef SGEN_HAVE_CONCURRENT_MARK
2048                                 card_data = card_base = block->cardtable_mod_union;
2049                                 /*
2050                                  * This happens when the nursery
2051                                  * collection that precedes finishing
2052                                  * the concurrent collection allocates
2053                                  * new major blocks.
2054                                  */
2055                                 if (!card_data)
2056                                         continue;
2057 #else
2058                                 g_assert_not_reached ();
2059                                 card_data = NULL;
2060 #endif
2061                         } else {
2062                                 card_data = card_base = sgen_card_table_get_card_scan_address ((mword)block_start);
2063                         }
2064                         card_data_end = card_data + CARDS_PER_BLOCK;
2065
2066                         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)) {
2067                                 size_t index;
2068                                 size_t idx = card_data - card_base;
2069                                 char *start = (char*)(block_start + idx * CARD_SIZE_IN_BYTES);
2070                                 char *end = start + CARD_SIZE_IN_BYTES;
2071                                 char *first_obj, *obj;
2072
2073                                 HEAVY_STAT (++scanned_cards);
2074
2075                                 if (!*card_data)
2076                                         continue;
2077
2078                                 if (!block->swept)
2079                                         sweep_block (block, FALSE);
2080
2081                                 HEAVY_STAT (++marked_cards);
2082
2083                                 sgen_card_table_prepare_card_for_scanning (card_data);
2084
2085                                 if (idx == 0)
2086                                         index = 0;
2087                                 else
2088                                         index = MS_BLOCK_OBJ_INDEX_FAST (start, block_start, block_obj_size);
2089
2090                                 obj = first_obj = (char*)MS_BLOCK_OBJ_FAST (block_start, block_obj_size, index);
2091                                 while (obj < end) {
2092                                         if (!MS_OBJ_ALLOCED_FAST (obj, block_start))
2093                                                 goto next_small;
2094
2095                                         if (mod_union) {
2096                                                 /* FIXME: do this more efficiently */
2097                                                 int w, b;
2098                                                 MS_CALC_MARK_BIT (w, b, obj);
2099                                                 if (!MS_MARK_BIT (block, w, b))
2100                                                         goto next_small;
2101                                         }
2102
2103                                         HEAVY_STAT (++scanned_objects);
2104                                         scan_func (obj, sgen_obj_get_descriptor (obj), queue);
2105                                 next_small:
2106                                         obj += block_obj_size;
2107                                 }
2108                                 HEAVY_STAT (if (*card_data) ++remarked_cards);
2109                                 binary_protocol_card_scan (first_obj, obj - first_obj);
2110                         }
2111                 }
2112         } END_FOREACH_BLOCK;
2113 }
2114
2115 static void
2116 major_count_cards (long long *num_total_cards, long long *num_marked_cards)
2117 {
2118         MSBlockInfo *block;
2119         gboolean has_references;
2120         long long total_cards = 0;
2121         long long marked_cards = 0;
2122
2123         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
2124                 guint8 *cards = sgen_card_table_get_card_scan_address ((mword) MS_BLOCK_FOR_BLOCK_INFO (block));
2125                 int i;
2126
2127                 if (!has_references)
2128                         continue;
2129
2130                 total_cards += CARDS_PER_BLOCK;
2131                 for (i = 0; i < CARDS_PER_BLOCK; ++i) {
2132                         if (cards [i])
2133                                 ++marked_cards;
2134                 }
2135         } END_FOREACH_BLOCK;
2136
2137         *num_total_cards = total_cards;
2138         *num_marked_cards = marked_cards;
2139 }
2140
2141 #ifdef SGEN_HAVE_CONCURRENT_MARK
2142 static void
2143 update_cardtable_mod_union (void)
2144 {
2145         MSBlockInfo *block;
2146
2147         FOREACH_BLOCK (block) {
2148                 size_t num_cards;
2149
2150                 block->cardtable_mod_union = sgen_card_table_update_mod_union (block->cardtable_mod_union,
2151                                 MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE, &num_cards);
2152
2153                 SGEN_ASSERT (0, num_cards == CARDS_PER_BLOCK, "Number of cards calculation is wrong");
2154         } END_FOREACH_BLOCK;
2155 }
2156
2157 static guint8*
2158 major_get_cardtable_mod_union_for_object (char *obj)
2159 {
2160         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
2161         return &block->cardtable_mod_union [(obj - (char*)sgen_card_table_align_pointer (MS_BLOCK_FOR_BLOCK_INFO (block))) >> CARD_BITS];
2162 }
2163 #endif
2164
2165 static void
2166 alloc_free_block_lists (MSBlockInfo ***lists)
2167 {
2168         int i;
2169         for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i)
2170                 lists [i] = sgen_alloc_internal_dynamic (sizeof (MSBlockInfo*) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2171 }
2172
2173 #undef pthread_create
2174
2175 static void
2176 post_param_init (SgenMajorCollector *collector)
2177 {
2178         collector->sweeps_lazily = lazy_sweep;
2179 }
2180
2181 #ifdef SGEN_HAVE_CONCURRENT_MARK
2182 static void
2183 sgen_marksweep_init_internal (SgenMajorCollector *collector, gboolean is_concurrent)
2184 #else // SGEN_HAVE_CONCURRENT_MARK
2185 #error unknown configuration
2186 #endif // SGEN_HAVE_CONCURRENT_MARK
2187 {
2188         int i;
2189
2190         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_MS_BLOCK_INFO, sizeof (MSBlockInfo));
2191
2192         num_block_obj_sizes = ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, NULL);
2193         block_obj_sizes = sgen_alloc_internal_dynamic (sizeof (int) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2194         ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, block_obj_sizes);
2195
2196         evacuate_block_obj_sizes = sgen_alloc_internal_dynamic (sizeof (gboolean) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2197         for (i = 0; i < num_block_obj_sizes; ++i)
2198                 evacuate_block_obj_sizes [i] = FALSE;
2199
2200         /*
2201         {
2202                 int i;
2203                 g_print ("block object sizes:\n");
2204                 for (i = 0; i < num_block_obj_sizes; ++i)
2205                         g_print ("%d\n", block_obj_sizes [i]);
2206         }
2207         */
2208
2209         alloc_free_block_lists (free_block_lists);
2210
2211         for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES; ++i)
2212                 fast_block_obj_size_indexes [i] = ms_find_block_obj_size_index (i * 8);
2213         for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES * 8; ++i)
2214                 g_assert (MS_BLOCK_OBJ_SIZE_INDEX (i) == ms_find_block_obj_size_index (i));
2215
2216         mono_counters_register ("# major blocks allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_alloced);
2217         mono_counters_register ("# major blocks freed", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed);
2218         mono_counters_register ("# major blocks lazy swept", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_lazy_swept);
2219         mono_counters_register ("# major objects evacuated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_objects_evacuated);
2220 #if SIZEOF_VOID_P != 8
2221         mono_counters_register ("# major blocks freed ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_ideal);
2222         mono_counters_register ("# major blocks freed less ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_less_ideal);
2223         mono_counters_register ("# major blocks freed individually", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_individual);
2224         mono_counters_register ("# major blocks allocated less ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_alloced_less_ideal);
2225 #endif
2226
2227         collector->section_size = MAJOR_SECTION_SIZE;
2228
2229 #ifdef SGEN_HAVE_CONCURRENT_MARK
2230         concurrent_mark = is_concurrent;
2231         if (is_concurrent) {
2232                 collector->is_concurrent = TRUE;
2233                 collector->want_synchronous_collection = &want_evacuation;
2234         } else
2235 #endif
2236         {
2237                 collector->is_concurrent = FALSE;
2238                 collector->want_synchronous_collection = NULL;
2239         }
2240         collector->get_and_reset_num_major_objects_marked = major_get_and_reset_num_major_objects_marked;
2241         collector->supports_cardtable = TRUE;
2242
2243         collector->have_swept = &have_swept;
2244
2245         collector->alloc_heap = major_alloc_heap;
2246         collector->is_object_live = major_is_object_live;
2247         collector->alloc_small_pinned_obj = major_alloc_small_pinned_obj;
2248         collector->alloc_degraded = major_alloc_degraded;
2249
2250         collector->alloc_object = major_alloc_object;
2251         collector->free_pinned_object = free_pinned_object;
2252         collector->iterate_objects = major_iterate_objects;
2253         collector->free_non_pinned_object = major_free_non_pinned_object;
2254         collector->find_pin_queue_start_ends = major_find_pin_queue_start_ends;
2255         collector->pin_objects = major_pin_objects;
2256         collector->pin_major_object = pin_major_object;
2257         collector->scan_card_table = major_scan_card_table;
2258         collector->iterate_live_block_ranges = (void*)(void*) major_iterate_live_block_ranges;
2259 #ifdef SGEN_HAVE_CONCURRENT_MARK
2260         if (is_concurrent) {
2261                 collector->update_cardtable_mod_union = update_cardtable_mod_union;
2262                 collector->get_cardtable_mod_union_for_object = major_get_cardtable_mod_union_for_object;
2263         }
2264 #endif
2265         collector->init_to_space = major_init_to_space;
2266         collector->sweep = major_sweep;
2267         collector->check_scan_starts = major_check_scan_starts;
2268         collector->dump_heap = major_dump_heap;
2269         collector->get_used_size = major_get_used_size;
2270         collector->start_nursery_collection = major_start_nursery_collection;
2271         collector->finish_nursery_collection = major_finish_nursery_collection;
2272         collector->start_major_collection = major_start_major_collection;
2273         collector->finish_major_collection = major_finish_major_collection;
2274         collector->have_computed_minor_collection_allowance = major_have_computer_minor_collection_allowance;
2275         collector->ptr_is_in_non_pinned_space = major_ptr_is_in_non_pinned_space;
2276         collector->obj_is_from_pinned_alloc = obj_is_from_pinned_alloc;
2277         collector->report_pinned_memory_usage = major_report_pinned_memory_usage;
2278         collector->get_num_major_sections = get_num_major_sections;
2279         collector->handle_gc_param = major_handle_gc_param;
2280         collector->print_gc_param_usage = major_print_gc_param_usage;
2281         collector->post_param_init = post_param_init;
2282         collector->is_valid_object = major_is_valid_object;
2283         collector->describe_pointer = major_describe_pointer;
2284         collector->count_cards = major_count_cards;
2285
2286         collector->major_ops.copy_or_mark_object = major_copy_or_mark_object_canonical;
2287         collector->major_ops.scan_object = major_scan_object;
2288 #ifdef SGEN_HAVE_CONCURRENT_MARK
2289         if (is_concurrent) {
2290                 collector->major_concurrent_ops.copy_or_mark_object = major_copy_or_mark_object_concurrent_canonical;
2291                 collector->major_concurrent_ops.scan_object = major_scan_object_concurrent;
2292                 collector->major_concurrent_ops.scan_vtype = major_scan_vtype_concurrent;
2293         }
2294 #endif
2295
2296 #if !defined (FIXED_HEAP) && !defined (SGEN_PARALLEL_MARK)
2297         /* FIXME: this will not work with evacuation or the split nursery. */
2298         if (!is_concurrent)
2299                 collector->drain_gray_stack = drain_gray_stack;
2300
2301 #ifdef HEAVY_STATISTICS
2302         mono_counters_register ("Optimized copy object called", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_copy_object_called);
2303         mono_counters_register ("Optimized nursery", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_nursery);
2304         mono_counters_register ("Optimized nursery forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_nursery_forwarded);
2305         mono_counters_register ("Optimized nursery pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_nursery_pinned);
2306         mono_counters_register ("Optimized major mark", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_mark);
2307         mono_counters_register ("Optimized major mark small", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_mark_small);
2308         mono_counters_register ("Optimized major mark large", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_mark_large);
2309         mono_counters_register ("Optimized major scan", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_scan);
2310         mono_counters_register ("Optimized major scan slow", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_scan_slow);
2311         mono_counters_register ("Optimized major scan fast", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_optimized_major_scan_fast);
2312
2313         mono_counters_register ("Gray stack drain loops", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_drain_loops);
2314         mono_counters_register ("Gray stack prefetch fills", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_drain_prefetch_fills);
2315         mono_counters_register ("Gray stack prefetch failures", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_drain_prefetch_fill_failures);
2316 #endif
2317 #endif
2318
2319 #ifdef HEAVY_STATISTICS
2320         mono_mutex_init (&scanned_objects_list_lock);
2321 #endif
2322
2323         /*cardtable requires major pages to be 8 cards aligned*/
2324         g_assert ((MS_BLOCK_SIZE % (8 * CARD_SIZE_IN_BYTES)) == 0);
2325 }
2326
2327 #ifdef SGEN_HAVE_CONCURRENT_MARK
2328 void
2329 sgen_marksweep_init (SgenMajorCollector *collector)
2330 {
2331         sgen_marksweep_init_internal (collector, FALSE);
2332 }
2333
2334 void
2335 sgen_marksweep_conc_init (SgenMajorCollector *collector)
2336 {
2337         sgen_marksweep_init_internal (collector, TRUE);
2338 }
2339 #endif
2340
2341 #endif