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
  45 #define SGEN_HAVE_CONCURRENT_MARK
  46
  47 #define MS_BLOCK_SIZE   (16*1024)
  48 #define MS_BLOCK_SIZE_SHIFT     14
  49 #define MAJOR_SECTION_SIZE      MS_BLOCK_SIZE
  50 #define CARDS_PER_BLOCK (MS_BLOCK_SIZE / CARD_SIZE_IN_BYTES)
  51
  52 /*
  53  * Don't allocate single blocks, but alloc a contingent of this many
  54  * blocks in one swoop.  This must be a power of two.
  55  */
  56 #define MS_BLOCK_ALLOC_NUM      32
  57
  58 /*
  59  * Number of bytes before the first object in a block.  At the start
  60  * of a block is the MSBlockHeader, then opional padding, then come
  61  * the objects, so this must be >= sizeof (MSBlockHeader).
  62  */
  63 #define MS_BLOCK_SKIP   16
  64
  65 #define MS_BLOCK_FREE   (MS_BLOCK_SIZE - MS_BLOCK_SKIP)
  66
  67 #define MS_NUM_MARK_WORDS       ((MS_BLOCK_SIZE / SGEN_ALLOC_ALIGN + sizeof (mword) * 8 - 1) / (sizeof (mword) * 8))
  68
  69 #if SGEN_MAX_SMALL_OBJ_SIZE > MS_BLOCK_FREE / 2
  70 #error MAX_SMALL_OBJ_SIZE must be at most MS_BLOCK_FREE / 2
  71 #endif
  72
  73 typedef struct _MSBlockInfo MSBlockInfo;
  74 struct _MSBlockInfo {
  75         int obj_size;
  76         int obj_size_index;
  77         size_t pin_queue_num_entries;
  78         unsigned int pinned : 1;
  79         unsigned int has_references : 1;
  80         unsigned int has_pinned : 1;    /* means cannot evacuate */
  81         unsigned int is_to_space : 1;
  82         unsigned int swept : 1;
  83         char *block;
  84         void **free_list;
  85         MSBlockInfo *next_free;
  86         void **pin_queue_start;
  87 #ifdef SGEN_HAVE_CONCURRENT_MARK
  88         guint8 *cardtable_mod_union;
  89 #endif
  90         mword mark_words [MS_NUM_MARK_WORDS];
  91 };
  92
  93 #define MS_BLOCK_FOR_BLOCK_INFO(b)      ((b)->block)
  94
  95 #define MS_BLOCK_OBJ(b,i)               (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (b)->obj_size * (i))
  96 #define MS_BLOCK_OBJ_FOR_SIZE(b,i,obj_size)             (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (obj_size) * (i))
  97 #define MS_BLOCK_DATA_FOR_OBJ(o)        ((char*)((mword)(o) & ~(mword)(MS_BLOCK_SIZE - 1)))
  98
  99 typedef struct {
 100         MSBlockInfo *info;
 101 } MSBlockHeader;
 102
 103 #define MS_BLOCK_FOR_OBJ(o)             (((MSBlockHeader*)MS_BLOCK_DATA_FOR_OBJ ((o)))->info)
 104
 105 /* object index will always be small */
 106 #define MS_BLOCK_OBJ_INDEX(o,b) ((int)(((char*)(o) - (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP)) / (b)->obj_size))
 107
 108 //casting to int is fine since blocks are 32k
 109 #define MS_CALC_MARK_BIT(w,b,o)         do {                            \
 110                 int i = ((int)((char*)(o) - MS_BLOCK_DATA_FOR_OBJ ((o)))) >> SGEN_ALLOC_ALIGN_BITS; \
 111                 if (sizeof (mword) == 4) {                              \
 112                         (w) = i >> 5;                                   \
 113                         (b) = i & 31;                                   \
 114                 } else {                                                \
 115                         (w) = i >> 6;                                   \
 116                         (b) = i & 63;                                   \
 117                 }                                                       \
 118         } while (0)
 119
 120 #define MS_MARK_BIT(bl,w,b)     ((bl)->mark_words [(w)] & (ONE_P << (b)))
 121 #define MS_SET_MARK_BIT(bl,w,b) ((bl)->mark_words [(w)] |= (ONE_P << (b)))
 122 #define MS_PAR_SET_MARK_BIT(was_marked,bl,w,b)  do {                    \
 123                 mword __old = (bl)->mark_words [(w)];                   \
 124                 mword __bitmask = ONE_P << (b);                         \
 125                 if (__old & __bitmask) {                                \
 126                         was_marked = TRUE;                              \
 127                         break;                                          \
 128                 }                                                       \
 129                 if (SGEN_CAS_PTR ((gpointer*)&(bl)->mark_words [(w)],   \
 130                                                 (gpointer)(__old | __bitmask), \
 131                                                 (gpointer)__old) ==     \
 132                                 (gpointer)__old) {                      \
 133                         was_marked = FALSE;                             \
 134                         break;                                          \
 135                 }                                                       \
 136         } while (1)
 137
 138 #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))
 139
 140 #define MS_BLOCK_OBJ_SIZE_FACTOR        (sqrt (2.0))
 141
 142 /*
 143  * This way we can lookup block object size indexes for sizes up to
 144  * 256 bytes with a single load.
 145  */
 146 #define MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES      32
 147
 148 static int *block_obj_sizes;
 149 static int num_block_obj_sizes;
 150 static int fast_block_obj_size_indexes [MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES];
 151
 152 #define MS_BLOCK_FLAG_PINNED    1
 153 #define MS_BLOCK_FLAG_REFS      2
 154
 155 #define MS_BLOCK_TYPE_MAX       4
 156
 157 static gboolean *evacuate_block_obj_sizes;
 158 static float evacuation_threshold = 0.666f;
 159 #ifdef SGEN_HAVE_CONCURRENT_MARK
 160 static float concurrent_evacuation_threshold = 0.666f;
 161 static gboolean want_evacuation = FALSE;
 162 #endif
 163
 164 static gboolean lazy_sweep = TRUE;
 165 static gboolean have_swept;
 166
 167 #ifdef SGEN_HAVE_CONCURRENT_MARK
 168 static gboolean concurrent_mark;
 169 #endif
 170
 171 #define BLOCK_IS_TAGGED_HAS_REFERENCES(bl)      SGEN_POINTER_IS_TAGGED_1 ((bl))
 172 #define BLOCK_TAG_HAS_REFERENCES(bl)            SGEN_POINTER_TAG_1 ((bl))
 173 #define BLOCK_UNTAG_HAS_REFERENCES(bl)          SGEN_POINTER_UNTAG_1 ((bl))
 174
 175 #define BLOCK_TAG(bl)   ((bl)->has_references ? BLOCK_TAG_HAS_REFERENCES ((bl)) : (bl))
 176
 177 /* all allocated blocks in the system */
 178 static SgenPointerQueue allocated_blocks;
 179
 180 /* non-allocated block free-list */
 181 static void *empty_blocks = NULL;
 182 static size_t num_empty_blocks = 0;
 183
 184 #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]);
 185 #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));
 186 #define END_FOREACH_BLOCK       } }
 187 #define DELETE_BLOCK_IN_FOREACH()       (allocated_blocks.data [__index] = NULL)
 188
 189 static size_t num_major_sections = 0;
 190 /* one free block list for each block object size */
 191 static MSBlockInfo **free_block_lists [MS_BLOCK_TYPE_MAX];
 192
 193 static long long stat_major_blocks_alloced = 0;
 194 static long long stat_major_blocks_freed = 0;
 195 static long long stat_major_blocks_lazy_swept = 0;
 196 static long long stat_major_objects_evacuated = 0;
 197
 198 #if SIZEOF_VOID_P != 8
 199 static long long stat_major_blocks_freed_ideal = 0;
 200 static long long stat_major_blocks_freed_less_ideal = 0;
 201 static long long stat_major_blocks_freed_individual = 0;
 202 static long long stat_major_blocks_alloced_less_ideal = 0;
 203 #endif
 204
 205 #ifdef SGEN_COUNT_NUMBER_OF_MAJOR_OBJECTS_MARKED
 206 static long long num_major_objects_marked = 0;
 207 #define INC_NUM_MAJOR_OBJECTS_MARKED()  (++num_major_objects_marked)
 208 #else
 209 #define INC_NUM_MAJOR_OBJECTS_MARKED()
 210 #endif
 211
 212 static void
 213 sweep_block (MSBlockInfo *block, gboolean during_major_collection);
 214
 215 static int
 216 ms_find_block_obj_size_index (size_t size)
 217 {
 218         int i;
 219         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);
 220         for (i = 0; i < num_block_obj_sizes; ++i)
 221                 if (block_obj_sizes [i] >= size)
 222                         return i;
 223         g_error ("no object of size %d\n", size);
 224 }
 225
 226 #define FREE_BLOCKS_FROM(lists,p,r)     (lists [((p) ? MS_BLOCK_FLAG_PINNED : 0) | ((r) ? MS_BLOCK_FLAG_REFS : 0)])
 227 #define FREE_BLOCKS(p,r)                (FREE_BLOCKS_FROM (free_block_lists, (p), (r)))
 228
 229 #define MS_BLOCK_OBJ_SIZE_INDEX(s)                              \
 230         (((s)+7)>>3 < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES ?      \
 231          fast_block_obj_size_indexes [((s)+7)>>3] :             \
 232          ms_find_block_obj_size_index ((s)))
 233
 234 static void*
 235 major_alloc_heap (mword nursery_size, mword nursery_align, int the_nursery_bits)
 236 {
 237         char *start;
 238         if (nursery_align)
 239                 start = sgen_alloc_os_memory_aligned (nursery_size, nursery_align, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE, "nursery");
 240         else
 241                 start = sgen_alloc_os_memory (nursery_size, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE, "nursery");
 242
 243         return start;
 244 }
 245
 246 static void
 247 update_heap_boundaries_for_block (MSBlockInfo *block)
 248 {
 249         sgen_update_heap_boundaries ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), (mword)MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE);
 250 }
 251
 252 static void*
 253 ms_get_empty_block (void)
 254 {
 255         char *p;
 256         int i;
 257         void *block, *empty, *next;
 258
 259  retry:
 260         if (!empty_blocks) {
 261                 /*
 262                  * We try allocating MS_BLOCK_ALLOC_NUM blocks first.  If that's
 263                  * unsuccessful, we halve the number of blocks and try again, until we're at
 264                  * 1.  If that doesn't work, either, we assert.
 265                  */
 266                 int alloc_num = MS_BLOCK_ALLOC_NUM;
 267                 for (;;) {
 268                         p = sgen_alloc_os_memory_aligned (MS_BLOCK_SIZE * alloc_num, MS_BLOCK_SIZE, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE,
 269                                         alloc_num == 1 ? "major heap section" : NULL);
 270                         if (p)
 271                                 break;
 272                         alloc_num >>= 1;
 273                 }
 274
 275                 for (i = 0; i < alloc_num; ++i) {
 276                         block = p;
 277                         /*
 278                          * We do the free list update one after the
 279                          * other so that other threads can use the new
 280                          * blocks as quickly as possible.
 281                          */
 282                         do {
 283                                 empty = empty_blocks;
 284                                 *(void**)block = empty;
 285                         } while (SGEN_CAS_PTR ((gpointer*)&empty_blocks, block, empty) != empty);
 286                         p += MS_BLOCK_SIZE;
 287                 }
 288
 289                 SGEN_ATOMIC_ADD_P (num_empty_blocks, alloc_num);
 290
 291                 stat_major_blocks_alloced += alloc_num;
 292 #if SIZEOF_VOID_P != 8
 293                 if (alloc_num != MS_BLOCK_ALLOC_NUM)
 294                         stat_major_blocks_alloced_less_ideal += alloc_num;
 295 #endif
 296         }
 297
 298         do {
 299                 empty = empty_blocks;
 300                 if (!empty)
 301                         goto retry;
 302                 block = empty;
 303                 next = *(void**)block;
 304         } while (SGEN_CAS_PTR (&empty_blocks, next, empty) != empty);
 305
 306         SGEN_ATOMIC_ADD_P (num_empty_blocks, -1);
 307
 308         *(void**)block = NULL;
 309
 310         g_assert (!((mword)block & (MS_BLOCK_SIZE - 1)));
 311
 312         return block;
 313 }
 314
 315 static void
 316 ms_free_block (void *block)
 317 {
 318         void *empty;
 319
 320         sgen_memgov_release_space (MS_BLOCK_SIZE, SPACE_MAJOR);
 321         memset (block, 0, MS_BLOCK_SIZE);
 322
 323         do {
 324                 empty = empty_blocks;
 325                 *(void**)block = empty;
 326         } while (SGEN_CAS_PTR (&empty_blocks, block, empty) != empty);
 327
 328         SGEN_ATOMIC_ADD_P (num_empty_blocks, 1);
 329 }
 330
 331 //#define MARKSWEEP_CONSISTENCY_CHECK
 332
 333 #ifdef MARKSWEEP_CONSISTENCY_CHECK
 334 static void
 335 check_block_free_list (MSBlockInfo *block, int size, gboolean pinned)
 336 {
 337         MSBlockInfo *b;
 338
 339         for (; block; block = block->next_free) {
 340                 g_assert (block->obj_size == size);
 341                 g_assert ((pinned && block->pinned) || (!pinned && !block->pinned));
 342
 343                 /* blocks in the free lists must have at least
 344                    one free slot */
 345                 if (block->swept)
 346                         g_assert (block->free_list);
 347
 348                 /* the block must be in the allocated_blocks array */
 349                 g_assert (sgen_pointer_queue_find (&allocated_blocks, BLOCK_TAG (block)) != (size_t)-1);
 350         }
 351 }
 352
 353 static void
 354 check_empty_blocks (void)
 355 {
 356         void *p;
 357         size_t i = 0;
 358         for (p = empty_blocks; p; p = *(void**)p)
 359                 ++i;
 360         g_assert (i == num_empty_blocks);
 361 }
 362
 363 static void
 364 consistency_check (void)
 365 {
 366         MSBlockInfo *block;
 367         int i;
 368
 369         /* check all blocks */
 370         FOREACH_BLOCK (block) {
 371                 int count = MS_BLOCK_FREE / block->obj_size;
 372                 int num_free = 0;
 373                 void **free;
 374
 375                 /* check block header */
 376                 g_assert (((MSBlockHeader*)block->block)->info == block);
 377
 378                 /* count number of free slots */
 379                 for (i = 0; i < count; ++i) {
 380                         void **obj = (void**) MS_BLOCK_OBJ (block, i);
 381                         if (!MS_OBJ_ALLOCED (obj, block))
 382                                 ++num_free;
 383                 }
 384
 385                 /* check free list */
 386                 for (free = block->free_list; free; free = (void**)*free) {
 387                         g_assert (MS_BLOCK_FOR_OBJ (free) == block);
 388                         --num_free;
 389                 }
 390                 g_assert (num_free == 0);
 391
 392                 /* check all mark words are zero */
 393                 if (block->swept) {
 394                         for (i = 0; i < MS_NUM_MARK_WORDS; ++i)
 395                                 g_assert (block->mark_words [i] == 0);
 396                 }
 397         } END_FOREACH_BLOCK;
 398
 399         /* check free blocks */
 400         for (i = 0; i < num_block_obj_sizes; ++i) {
 401                 int j;
 402                 for (j = 0; j < MS_BLOCK_TYPE_MAX; ++j)
 403                         check_block_free_list (free_block_lists [j][i], block_obj_sizes [i], j & MS_BLOCK_FLAG_PINNED);
 404         }
 405
 406         check_empty_blocks ();
 407 }
 408 #endif
 409
 410 static gboolean
 411 ms_alloc_block (int size_index, gboolean pinned, gboolean has_references)
 412 {
 413         int size = block_obj_sizes [size_index];
 414         int count = MS_BLOCK_FREE / size;
 415         MSBlockInfo *info;
 416         MSBlockHeader *header;
 417         MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, has_references);
 418         char *obj_start;
 419         int i;
 420
 421         if (!sgen_memgov_try_alloc_space (MS_BLOCK_SIZE, SPACE_MAJOR))
 422                 return FALSE;
 423
 424         info = sgen_alloc_internal (INTERNAL_MEM_MS_BLOCK_INFO);
 425
 426         SGEN_ASSERT (9, count >= 2, "block with %d objects, it must hold at least 2", count);
 427
 428         info->obj_size = size;
 429         info->obj_size_index = size_index;
 430         info->pinned = pinned;
 431         info->has_references = has_references;
 432         info->has_pinned = pinned;
 433         /*
 434          * Blocks that are to-space are not evacuated from.  During an major collection
 435          * blocks are allocated for two reasons: evacuating objects from the nursery and
 436          * evacuating them from major blocks marked for evacuation.  In both cases we don't
 437          * want further evacuation.
 438          */
 439         info->is_to_space = (sgen_get_current_collection_generation () == GENERATION_OLD);
 440         info->swept = 1;
 441         info->block = ms_get_empty_block ();
 442
 443         header = (MSBlockHeader*) info->block;
 444         header->info = info;
 445 #ifdef SGEN_HAVE_CONCURRENT_MARK
 446         info->cardtable_mod_union = NULL;
 447 #endif
 448
 449         update_heap_boundaries_for_block (info);
 450
 451         /* build free list */
 452         obj_start = MS_BLOCK_FOR_BLOCK_INFO (info) + MS_BLOCK_SKIP;
 453         info->free_list = (void**)obj_start;
 454         /* we're skipping the last one - it must be nulled */
 455         for (i = 0; i < count - 1; ++i) {
 456                 char *next_obj_start = obj_start + size;
 457                 *(void**)obj_start = next_obj_start;
 458                 obj_start = next_obj_start;
 459         }
 460         /* the last one */
 461         *(void**)obj_start = NULL;
 462
 463         info->next_free = free_blocks [size_index];
 464         free_blocks [size_index] = info;
 465
 466         sgen_pointer_queue_add (&allocated_blocks, BLOCK_TAG (info));
 467
 468         ++num_major_sections;
 469         return TRUE;
 470 }
 471
 472 static gboolean
 473 obj_is_from_pinned_alloc (char *ptr)
 474 {
 475         MSBlockInfo *block;
 476
 477         FOREACH_BLOCK (block) {
 478                 if (ptr >= MS_BLOCK_FOR_BLOCK_INFO (block) && ptr <= MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE)
 479                         return block->pinned;
 480         } END_FOREACH_BLOCK;
 481         return FALSE;
 482 }
 483
 484 static void*
 485 unlink_slot_from_free_list_uncontested (MSBlockInfo **free_blocks, int size_index)
 486 {
 487         MSBlockInfo *block;
 488         void *obj;
 489
 490         block = free_blocks [size_index];
 491         SGEN_ASSERT (9, block, "no free block to unlink from free_blocks %p size_index %d", free_blocks, size_index);
 492
 493         if (G_UNLIKELY (!block->swept)) {
 494                 stat_major_blocks_lazy_swept ++;
 495                 sweep_block (block, FALSE);
 496         }
 497
 498         obj = block->free_list;
 499         SGEN_ASSERT (9, obj, "block %p in free list had no available object to alloc from", block);
 500
 501         block->free_list = *(void**)obj;
 502         if (!block->free_list) {
 503                 free_blocks [size_index] = block->next_free;
 504                 block->next_free = NULL;
 505         }
 506
 507         return obj;
 508 }
 509
 510 static void*
 511 alloc_obj (MonoVTable *vtable, size_t size, gboolean pinned, gboolean has_references)
 512 {
 513         int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
 514         MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, has_references);
 515         void *obj;
 516
 517         if (!free_blocks [size_index]) {
 518                 if (G_UNLIKELY (!ms_alloc_block (size_index, pinned, has_references)))
 519                         return NULL;
 520         }
 521
 522         obj = unlink_slot_from_free_list_uncontested (free_blocks, size_index);
 523
 524         *(MonoVTable**)obj = vtable;
 525
 526         return obj;
 527 }
 528
 529 static void*
 530 major_alloc_object (MonoVTable *vtable, size_t size, gboolean has_references)
 531 {
 532         return alloc_obj (vtable, size, FALSE, has_references);
 533 }
 534
 535 /*
 536  * We're not freeing the block if it's empty.  We leave that work for
 537  * the next major collection.
 538  *
 539  * This is just called from the domain clearing code, which runs in a
 540  * single thread and has the GC lock, so we don't need an extra lock.
 541  */
 542 static void
 543 free_object (char *obj, size_t size, gboolean pinned)
 544 {
 545         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
 546         int word, bit;
 547
 548         if (!block->swept)
 549                 sweep_block (block, FALSE);
 550         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);
 551         SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p is already free", obj);
 552         MS_CALC_MARK_BIT (word, bit, obj);
 553         SGEN_ASSERT (9, !MS_MARK_BIT (block, word, bit), "object %p has mark bit set");
 554         if (!block->free_list) {
 555                 MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, block->has_references);
 556                 int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
 557                 SGEN_ASSERT (9, !block->next_free, "block %p doesn't have a free-list of object but belongs to a free-list of blocks");
 558                 block->next_free = free_blocks [size_index];
 559                 free_blocks [size_index] = block;
 560         }
 561         memset (obj, 0, size);
 562         *(void**)obj = block->free_list;
 563         block->free_list = (void**)obj;
 564 }
 565
 566 static void
 567 major_free_non_pinned_object (char *obj, size_t size)
 568 {
 569         free_object (obj, size, FALSE);
 570 }
 571
 572 /* size is a multiple of SGEN_ALLOC_ALIGN */
 573 static void*
 574 major_alloc_small_pinned_obj (MonoVTable *vtable, size_t size, gboolean has_references)
 575 {
 576         void *res;
 577
 578         res = alloc_obj (vtable, size, TRUE, has_references);
 579          /*If we failed to alloc memory, we better try releasing memory
 580           *as pinned alloc is requested by the runtime.
 581           */
 582          if (!res) {
 583                 sgen_perform_collection (0, GENERATION_OLD, "pinned alloc failure", TRUE);
 584                 res = alloc_obj (vtable, size, TRUE, has_references);
 585          }
 586          return res;
 587 }
 588
 589 static void
 590 free_pinned_object (char *obj, size_t size)
 591 {
 592         free_object (obj, size, TRUE);
 593 }
 594
 595 /*
 596  * size is already rounded up and we hold the GC lock.
 597  */
 598 static void*
 599 major_alloc_degraded (MonoVTable *vtable, size_t size)
 600 {
 601         void *obj;
 602         size_t old_num_sections;
 603
 604         old_num_sections = num_major_sections;
 605
 606         obj = alloc_obj (vtable, size, FALSE, SGEN_VTABLE_HAS_REFERENCES (vtable));
 607         if (G_LIKELY (obj)) {
 608                 HEAVY_STAT (++stat_objects_alloced_degraded);
 609                 HEAVY_STAT (stat_bytes_alloced_degraded += size);
 610                 g_assert (num_major_sections >= old_num_sections);
 611                 sgen_register_major_sections_alloced (num_major_sections - old_num_sections);
 612         }
 613         return obj;
 614 }
 615
 616 #define MAJOR_OBJ_IS_IN_TO_SPACE(obj)   FALSE
 617
 618 /*
 619  * obj is some object.  If it's not in the major heap (i.e. if it's in
 620  * the nursery or LOS), return FALSE.  Otherwise return whether it's
 621  * been marked or copied.
 622  */
 623 static gboolean
 624 major_is_object_live (char *obj)
 625 {
 626         MSBlockInfo *block;
 627         int word, bit;
 628         mword objsize;
 629
 630         if (sgen_ptr_in_nursery (obj))
 631                 return FALSE;
 632
 633         objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
 634
 635         /* LOS */
 636         if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
 637                 return FALSE;
 638
 639         /* now we know it's in a major block */
 640         block = MS_BLOCK_FOR_OBJ (obj);
 641         SGEN_ASSERT (9, !block->pinned, "block %p is pinned, BTW why is this bad?");
 642         MS_CALC_MARK_BIT (word, bit, obj);
 643         return MS_MARK_BIT (block, word, bit) ? TRUE : FALSE;
 644 }
 645
 646 static gboolean
 647 major_ptr_is_in_non_pinned_space (char *ptr, char **start)
 648 {
 649         MSBlockInfo *block;
 650
 651         FOREACH_BLOCK (block) {
 652                 if (ptr >= MS_BLOCK_FOR_BLOCK_INFO (block) && ptr <= MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) {
 653                         int count = MS_BLOCK_FREE / block->obj_size;
 654                         int i;
 655
 656                         *start = NULL;
 657                         for (i = 0; i <= count; ++i) {
 658                                 if (ptr >= MS_BLOCK_OBJ (block, i) && ptr < MS_BLOCK_OBJ (block, i + 1)) {
 659                                         *start = MS_BLOCK_OBJ (block, i);
 660                                         break;
 661                                 }
 662                         }
 663                         return !block->pinned;
 664                 }
 665         } END_FOREACH_BLOCK;
 666         return FALSE;
 667 }
 668
 669 static void
 670 major_iterate_objects (IterateObjectsFlags flags, IterateObjectCallbackFunc callback, void *data)
 671 {
 672         gboolean sweep = flags & ITERATE_OBJECTS_SWEEP;
 673         gboolean non_pinned = flags & ITERATE_OBJECTS_NON_PINNED;
 674         gboolean pinned = flags & ITERATE_OBJECTS_PINNED;
 675         MSBlockInfo *block;
 676
 677         FOREACH_BLOCK (block) {
 678                 int count = MS_BLOCK_FREE / block->obj_size;
 679                 int i;
 680
 681                 if (block->pinned && !pinned)
 682                         continue;
 683                 if (!block->pinned && !non_pinned)
 684                         continue;
 685                 if (sweep && lazy_sweep) {
 686                         sweep_block (block, FALSE);
 687                         SGEN_ASSERT (0, block->swept, "Block must be swept after sweeping");
 688                 }
 689
 690                 for (i = 0; i < count; ++i) {
 691                         void **obj = (void**) MS_BLOCK_OBJ (block, i);
 692                         if (!block->swept) {
 693                                 int word, bit;
 694                                 MS_CALC_MARK_BIT (word, bit, obj);
 695                                 if (!MS_MARK_BIT (block, word, bit))
 696                                         continue;
 697                         }
 698                         if (MS_OBJ_ALLOCED (obj, block))
 699                                 callback ((char*)obj, block->obj_size, data);
 700                 }
 701         } END_FOREACH_BLOCK;
 702 }
 703
 704 static gboolean
 705 major_is_valid_object (char *object)
 706 {
 707         MSBlockInfo *block;
 708
 709         FOREACH_BLOCK (block) {
 710                 int idx;
 711                 char *obj;
 712
 713                 if ((MS_BLOCK_FOR_BLOCK_INFO (block) > object) || ((MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) <= object))
 714                         continue;
 715
 716                 idx = MS_BLOCK_OBJ_INDEX (object, block);
 717                 obj = (char*)MS_BLOCK_OBJ (block, idx);
 718                 if (obj != object)
 719                         return FALSE;
 720                 return MS_OBJ_ALLOCED (obj, block);
 721         } END_FOREACH_BLOCK;
 722
 723         return FALSE;
 724 }
 725
 726
 727 static MonoVTable*
 728 major_describe_pointer (char *ptr)
 729 {
 730         MSBlockInfo *block;
 731
 732         FOREACH_BLOCK (block) {
 733                 int idx;
 734                 char *obj;
 735                 gboolean live;
 736                 MonoVTable *vtable;
 737                 int w, b;
 738                 gboolean marked;
 739
 740                 if ((MS_BLOCK_FOR_BLOCK_INFO (block) > ptr) || ((MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE) <= ptr))
 741                         continue;
 742
 743                 SGEN_LOG (0, "major-ptr (block %p sz %d pin %d ref %d)\n",
 744                         MS_BLOCK_FOR_BLOCK_INFO (block), block->obj_size, block->pinned, block->has_references);
 745
 746                 idx = MS_BLOCK_OBJ_INDEX (ptr, block);
 747                 obj = (char*)MS_BLOCK_OBJ (block, idx);
 748                 live = MS_OBJ_ALLOCED (obj, block);
 749                 vtable = live ? (MonoVTable*)SGEN_LOAD_VTABLE (obj) : NULL;
 750
 751                 MS_CALC_MARK_BIT (w, b, obj);
 752                 marked = MS_MARK_BIT (block, w, b);
 753
 754                 if (obj == ptr) {
 755                         SGEN_LOG (0, "\t(");
 756                         if (live)
 757                                 SGEN_LOG (0, "object");
 758                         else
 759                                 SGEN_LOG (0, "dead-object");
 760                 } else {
 761                         if (live)
 762                                 SGEN_LOG (0, "interior-ptr offset %td", ptr - obj);
 763                         else
 764                                 SGEN_LOG (0, "dead-interior-ptr offset %td", ptr - obj);
 765                 }
 766
 767                 SGEN_LOG (0, " marked %d)\n", marked ? 1 : 0);
 768
 769                 return vtable;
 770         } END_FOREACH_BLOCK;
 771
 772         return NULL;
 773 }
 774
 775 static void
 776 major_check_scan_starts (void)
 777 {
 778 }
 779
 780 static void
 781 major_dump_heap (FILE *heap_dump_file)
 782 {
 783         MSBlockInfo *block;
 784         int *slots_available = alloca (sizeof (int) * num_block_obj_sizes);
 785         int *slots_used = alloca (sizeof (int) * num_block_obj_sizes);
 786         int i;
 787
 788         for (i = 0; i < num_block_obj_sizes; ++i)
 789                 slots_available [i] = slots_used [i] = 0;
 790
 791         FOREACH_BLOCK (block) {
 792                 int index = ms_find_block_obj_size_index (block->obj_size);
 793                 int count = MS_BLOCK_FREE / block->obj_size;
 794
 795                 slots_available [index] += count;
 796                 for (i = 0; i < count; ++i) {
 797                         if (MS_OBJ_ALLOCED (MS_BLOCK_OBJ (block, i), block))
 798                                 ++slots_used [index];
 799                 }
 800         } END_FOREACH_BLOCK;
 801
 802         fprintf (heap_dump_file, "<occupancies>\n");
 803         for (i = 0; i < num_block_obj_sizes; ++i) {
 804                 fprintf (heap_dump_file, "<occupancy size=\"%d\" available=\"%d\" used=\"%d\" />\n",
 805                                 block_obj_sizes [i], slots_available [i], slots_used [i]);
 806         }
 807         fprintf (heap_dump_file, "</occupancies>\n");
 808
 809         FOREACH_BLOCK (block) {
 810                 int count = MS_BLOCK_FREE / block->obj_size;
 811                 int i;
 812                 int start = -1;
 813
 814                 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%zu\">\n", "old", (size_t)MS_BLOCK_FREE);
 815
 816                 for (i = 0; i <= count; ++i) {
 817                         if ((i < count) && MS_OBJ_ALLOCED (MS_BLOCK_OBJ (block, i), block)) {
 818                                 if (start < 0)
 819                                         start = i;
 820                         } else {
 821                                 if (start >= 0) {
 822                                         sgen_dump_occupied (MS_BLOCK_OBJ (block, start), MS_BLOCK_OBJ (block, i), MS_BLOCK_FOR_BLOCK_INFO (block));
 823                                         start = -1;
 824                                 }
 825                         }
 826                 }
 827
 828                 fprintf (heap_dump_file, "</section>\n");
 829         } END_FOREACH_BLOCK;
 830 }
 831
 832 #define LOAD_VTABLE     SGEN_LOAD_VTABLE
 833
 834 #define MS_MARK_OBJECT_AND_ENQUEUE_CHECKED(obj,desc,block,queue) do {   \
 835                 int __word, __bit;                                      \
 836                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 837                 if (!MS_MARK_BIT ((block), __word, __bit) && MS_OBJ_ALLOCED ((obj), (block))) { \
 838                         MS_SET_MARK_BIT ((block), __word, __bit);       \
 839                         if ((block)->has_references)                    \
 840                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 841                         binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 842                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 843                 }                                                       \
 844         } while (0)
 845 #define MS_MARK_OBJECT_AND_ENQUEUE(obj,desc,block,queue) do {           \
 846                 int __word, __bit;                                      \
 847                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 848                 SGEN_ASSERT (9, MS_OBJ_ALLOCED ((obj), (block)), "object %p not allocated", obj);       \
 849                 if (!MS_MARK_BIT ((block), __word, __bit)) {            \
 850                         MS_SET_MARK_BIT ((block), __word, __bit);       \
 851                         if ((block)->has_references)                    \
 852                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 853                         binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 854                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 855                 }                                                       \
 856         } while (0)
 857 #define MS_PAR_MARK_OBJECT_AND_ENQUEUE(obj,desc,block,queue) do {       \
 858                 int __word, __bit;                                      \
 859                 gboolean __was_marked;                                  \
 860                 SGEN_ASSERT (9, MS_OBJ_ALLOCED ((obj), (block)), "object %p not allocated", obj);       \
 861                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 862                 MS_PAR_SET_MARK_BIT (__was_marked, (block), __word, __bit); \
 863                 if (!__was_marked) {                                    \
 864                         if ((block)->has_references)                    \
 865                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 866                         binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 867                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 868                 }                                                       \
 869         } while (0)
 870
 871 static void
 872 pin_major_object (char *obj, SgenGrayQueue *queue)
 873 {
 874         MSBlockInfo *block;
 875
 876 #ifdef SGEN_HAVE_CONCURRENT_MARK
 877         if (concurrent_mark)
 878                 g_assert_not_reached ();
 879 #endif
 880
 881         block = MS_BLOCK_FOR_OBJ (obj);
 882         block->has_pinned = TRUE;
 883         MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 884 }
 885
 886 #include "sgen-major-copy-object.h"
 887
 888 #ifdef SGEN_HAVE_CONCURRENT_MARK
 889 static void
 890 major_copy_or_mark_object_concurrent (void **ptr, void *obj, SgenGrayQueue *queue)
 891 {
 892         g_assert (!SGEN_OBJECT_IS_FORWARDED (obj));
 893
 894         if (!sgen_ptr_in_nursery (obj)) {
 895                 mword objsize;
 896
 897                 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
 898
 899                 if (objsize <= SGEN_MAX_SMALL_OBJ_SIZE) {
 900                         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
 901                         MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 902                 } else {
 903                         if (sgen_los_object_is_pinned (obj))
 904                                 return;
 905
 906 #ifdef ENABLE_DTRACE
 907                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
 908                                 MonoVTable *vt = (MonoVTable*)SGEN_LOAD_VTABLE (obj);
 909                                 MONO_GC_OBJ_PINNED ((mword)obj, sgen_safe_object_get_size (obj), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
 910                         }
 911 #endif
 912
 913                         sgen_los_pin_object (obj);
 914                         if (SGEN_OBJECT_HAS_REFERENCES (obj))
 915                                 GRAY_OBJECT_ENQUEUE (queue, obj, sgen_obj_get_descriptor (obj));
 916                         INC_NUM_MAJOR_OBJECTS_MARKED ();
 917                 }
 918         }
 919 }
 920 #endif
 921
 922 static void
 923 major_copy_or_mark_object (void **ptr, void *obj, SgenGrayQueue *queue)
 924 {
 925         MSBlockInfo *block;
 926
 927         HEAVY_STAT (++stat_copy_object_called_major);
 928
 929         SGEN_ASSERT (9, obj, "null object from pointer %p", ptr);
 930         SGEN_ASSERT (9, current_collection_generation == GENERATION_OLD, "old gen parallel allocator called from a %d collection", current_collection_generation);
 931
 932         if (sgen_ptr_in_nursery (obj)) {
 933                 int word, bit;
 934                 char *forwarded, *old_obj;
 935
 936                 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 937                         *ptr = forwarded;
 938                         return;
 939                 }
 940                 if (SGEN_OBJECT_IS_PINNED (obj))
 941                         return;
 942
 943                 /* An object in the nursery To Space has already been copied and grayed. Nothing to do. */
 944                 if (sgen_nursery_is_to_space (obj))
 945                         return;
 946
 947                 HEAVY_STAT (++stat_objects_copied_major);
 948
 949         do_copy_object:
 950                 old_obj = obj;
 951                 obj = copy_object_no_checks (obj, queue);
 952                 if (G_UNLIKELY (old_obj == obj)) {
 953                         /*If we fail to evacuate an object we just stop doing it for a given block size as all other will surely fail too.*/
 954                         if (!sgen_ptr_in_nursery (obj)) {
 955                                 int size_index;
 956                                 block = MS_BLOCK_FOR_OBJ (obj);
 957                                 size_index = block->obj_size_index;
 958                                 evacuate_block_obj_sizes [size_index] = FALSE;
 959                                 MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 960                         }
 961                         return;
 962                 }
 963                 *ptr = obj;
 964
 965                 /*
 966                  * FIXME: See comment for copy_object_no_checks().  If
 967                  * we have that, we can let the allocation function
 968                  * give us the block info, too, and we won't have to
 969                  * re-fetch it.
 970                  *
 971                  * FIXME (2): We should rework this to avoid all those nursery checks.
 972                  */
 973                 /*
 974                  * For the split nursery allocator the object might
 975                  * still be in the nursery despite having being
 976                  * promoted, in which case we can't mark it.
 977                  */
 978                 if (!sgen_ptr_in_nursery (obj)) {
 979                         block = MS_BLOCK_FOR_OBJ (obj);
 980                         MS_CALC_MARK_BIT (word, bit, obj);
 981                         SGEN_ASSERT (9, !MS_MARK_BIT (block, word, bit), "object %p already marked", 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         } else {
 986                 char *forwarded;
 987                 mword objsize;
 988
 989                 /*
 990                  * If we have don't have a fixed heap we cannot know
 991                  * whether an object is in the LOS or in the small
 992                  * object major heap without checking its size.  To do
 993                  * that, however, we need to know that we actually
 994                  * have a valid object, not a forwarding pointer, so
 995                  * we have to do this check first.
 996                  */
 997                 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 998                         *ptr = forwarded;
 999                         return;
1000                 }
1001
1002                 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
1003
1004                 if (objsize <= SGEN_MAX_SMALL_OBJ_SIZE) {
1005                         int size_index;
1006                         gboolean evacuate;
1007
1008                         block = MS_BLOCK_FOR_OBJ (obj);
1009                         size_index = block->obj_size_index;
1010                         evacuate = evacuate_block_obj_sizes [size_index];
1011
1012                         if (evacuate && !block->has_pinned) {
1013                                 g_assert (!SGEN_OBJECT_IS_PINNED (obj));
1014                                 if (block->is_to_space)
1015                                         return;
1016                                 HEAVY_STAT (++stat_major_objects_evacuated);
1017                                 goto do_copy_object;
1018                         } else {
1019                                 MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
1020                         }
1021                 } else {
1022                         if (sgen_los_object_is_pinned (obj))
1023                                 return;
1024                         binary_protocol_pin (obj, (gpointer)SGEN_LOAD_VTABLE (obj), sgen_safe_object_get_size ((MonoObject*)obj));
1025
1026 #ifdef ENABLE_DTRACE
1027                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1028                                 MonoVTable *vt = (MonoVTable*)SGEN_LOAD_VTABLE (obj);
1029                                 MONO_GC_OBJ_PINNED ((mword)obj, sgen_safe_object_get_size (obj), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
1030                         }
1031 #endif
1032
1033                         sgen_los_pin_object (obj);
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 static void
1075 mark_pinned_objects_in_block (MSBlockInfo *block, SgenGrayQueue *queue)
1076 {
1077         int i;
1078         int last_index = -1;
1079
1080         if (!block->pin_queue_num_entries)
1081                 return;
1082
1083         block->has_pinned = TRUE;
1084
1085         for (i = 0; i < block->pin_queue_num_entries; ++i) {
1086                 int index = MS_BLOCK_OBJ_INDEX (block->pin_queue_start [i], block);
1087                 char *obj;
1088                 SGEN_ASSERT (9, index >= 0 && index < MS_BLOCK_FREE / block->obj_size, "invalid object %p index %d max-index %d", block->pin_queue_start [i], index, MS_BLOCK_FREE / block->obj_size);
1089                 if (index == last_index)
1090                         continue;
1091                 obj = MS_BLOCK_OBJ (block, index);
1092                 MS_MARK_OBJECT_AND_ENQUEUE_CHECKED (obj, sgen_obj_get_descriptor (obj), block, queue);
1093                 last_index = index;
1094         }
1095 }
1096
1097 static inline void
1098 sweep_block_for_size (MSBlockInfo *block, int count, int obj_size)
1099 {
1100         int obj_index;
1101
1102         for (obj_index = 0; obj_index < count; ++obj_index) {
1103                 int word, bit;
1104                 void *obj = MS_BLOCK_OBJ_FOR_SIZE (block, obj_index, obj_size);
1105
1106                 MS_CALC_MARK_BIT (word, bit, obj);
1107                 if (MS_MARK_BIT (block, word, bit)) {
1108                         SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p not allocated", obj);
1109                 } else {
1110                         /* an unmarked object */
1111                         if (MS_OBJ_ALLOCED (obj, block)) {
1112                                 /*
1113                                  * FIXME: Merge consecutive
1114                                  * slots for lower reporting
1115                                  * overhead.  Maybe memset
1116                                  * will also benefit?
1117                                  */
1118                                 binary_protocol_empty (obj, obj_size);
1119                                 MONO_GC_MAJOR_SWEPT ((mword)obj, obj_size);
1120                                 memset (obj, 0, obj_size);
1121                         }
1122                         *(void**)obj = block->free_list;
1123                         block->free_list = obj;
1124                 }
1125         }
1126 }
1127
1128 /*
1129  * sweep_block:
1130  *
1131  *   Traverse BLOCK, freeing and zeroing unused objects.
1132  */
1133 static void
1134 sweep_block (MSBlockInfo *block, gboolean during_major_collection)
1135 {
1136         int count;
1137         void *reversed = NULL;
1138
1139         if (!during_major_collection)
1140                 g_assert (!sgen_concurrent_collection_in_progress ());
1141
1142         if (block->swept)
1143                 return;
1144
1145         count = MS_BLOCK_FREE / block->obj_size;
1146
1147         block->free_list = NULL;
1148
1149         /* Use inline instances specialized to constant sizes, this allows the compiler to replace the memset calls with inline code */
1150         // FIXME: Add more sizes
1151         switch (block->obj_size) {
1152         case 16:
1153                 sweep_block_for_size (block, count, 16);
1154                 break;
1155         default:
1156                 sweep_block_for_size (block, count, block->obj_size);
1157                 break;
1158         }
1159
1160         /* reset mark bits */
1161         memset (block->mark_words, 0, sizeof (mword) * MS_NUM_MARK_WORDS);
1162
1163         /* Reverse free list so that it's in address order */
1164         reversed = NULL;
1165         while (block->free_list) {
1166                 void *next = *(void**)block->free_list;
1167                 *(void**)block->free_list = reversed;
1168                 reversed = block->free_list;
1169                 block->free_list = next;
1170         }
1171         block->free_list = reversed;
1172
1173         block->swept = 1;
1174 }
1175
1176 static inline int
1177 bitcount (mword d)
1178 {
1179         int count = 0;
1180
1181 #ifdef __GNUC__
1182         if (sizeof (mword) == sizeof (unsigned long))
1183                 count += __builtin_popcountl (d);
1184         else
1185                 count += __builtin_popcount (d);
1186 #else
1187         while (d) {
1188                 count ++;
1189                 d &= (d - 1);
1190         }
1191 #endif
1192         return count;
1193 }
1194
1195 static void
1196 ms_sweep (void)
1197 {
1198         int i;
1199         MSBlockInfo *block;
1200
1201         /* statistics for evacuation */
1202         int *slots_available = alloca (sizeof (int) * num_block_obj_sizes);
1203         int *slots_used = alloca (sizeof (int) * num_block_obj_sizes);
1204         int *num_blocks = alloca (sizeof (int) * num_block_obj_sizes);
1205
1206 #ifdef SGEN_HAVE_CONCURRENT_MARK
1207         mword total_evacuate_heap = 0;
1208         mword total_evacuate_saved = 0;
1209 #endif
1210
1211         for (i = 0; i < num_block_obj_sizes; ++i)
1212                 slots_available [i] = slots_used [i] = num_blocks [i] = 0;
1213
1214         /* clear all the free lists */
1215         for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i) {
1216                 MSBlockInfo **free_blocks = free_block_lists [i];
1217                 int j;
1218                 for (j = 0; j < num_block_obj_sizes; ++j)
1219                         free_blocks [j] = NULL;
1220         }
1221
1222         /* traverse all blocks, free and zero unmarked objects */
1223         FOREACH_BLOCK (block) {
1224                 int count;
1225                 gboolean have_live = FALSE;
1226                 gboolean has_pinned;
1227                 gboolean have_free = FALSE;
1228                 int obj_size_index;
1229                 int nused = 0;
1230
1231                 obj_size_index = block->obj_size_index;
1232
1233                 has_pinned = block->has_pinned;
1234                 block->has_pinned = block->pinned;
1235
1236                 block->is_to_space = FALSE;
1237                 block->swept = 0;
1238
1239                 count = MS_BLOCK_FREE / block->obj_size;
1240
1241 #ifdef SGEN_HAVE_CONCURRENT_MARK
1242                 if (block->cardtable_mod_union) {
1243                         sgen_free_internal_dynamic (block->cardtable_mod_union, CARDS_PER_BLOCK, INTERNAL_MEM_CARDTABLE_MOD_UNION);
1244                         block->cardtable_mod_union = NULL;
1245                 }
1246 #endif
1247
1248                 /* Count marked objects in the block */
1249                 for (i = 0; i < MS_NUM_MARK_WORDS; ++i) {
1250                         nused += bitcount (block->mark_words [i]);
1251                 }
1252                 if (nused) {
1253                         have_live = TRUE;
1254                 }
1255                 if (nused < count)
1256                         have_free = TRUE;
1257
1258                 if (!lazy_sweep)
1259                         sweep_block (block, TRUE);
1260
1261                 if (have_live) {
1262                         if (!has_pinned) {
1263                                 ++num_blocks [obj_size_index];
1264                                 slots_used [obj_size_index] += nused;
1265                                 slots_available [obj_size_index] += count;
1266                         }
1267
1268                         /*
1269                          * If there are free slots in the block, add
1270                          * the block to the corresponding free list.
1271                          */
1272                         if (have_free) {
1273                                 MSBlockInfo **free_blocks = FREE_BLOCKS (block->pinned, block->has_references);
1274                                 int index = MS_BLOCK_OBJ_SIZE_INDEX (block->obj_size);
1275                                 block->next_free = free_blocks [index];
1276                                 free_blocks [index] = block;
1277                         }
1278
1279                         update_heap_boundaries_for_block (block);
1280                 } else {
1281                         /*
1282                          * Blocks without live objects are removed from the
1283                          * block list and freed.
1284                          */
1285                         DELETE_BLOCK_IN_FOREACH ();
1286
1287                         binary_protocol_empty (MS_BLOCK_OBJ (block, 0), (char*)MS_BLOCK_OBJ (block, count) - (char*)MS_BLOCK_OBJ (block, 0));
1288                         ms_free_block (block->block);
1289                         sgen_free_internal (block, INTERNAL_MEM_MS_BLOCK_INFO);
1290
1291                         --num_major_sections;
1292                 }
1293         } END_FOREACH_BLOCK;
1294         sgen_pointer_queue_remove_nulls (&allocated_blocks);
1295
1296         for (i = 0; i < num_block_obj_sizes; ++i) {
1297                 float usage = (float)slots_used [i] / (float)slots_available [i];
1298                 if (num_blocks [i] > 5 && usage < evacuation_threshold) {
1299                         evacuate_block_obj_sizes [i] = TRUE;
1300                         /*
1301                         g_print ("slot size %d - %d of %d used\n",
1302                                         block_obj_sizes [i], slots_used [i], slots_available [i]);
1303                         */
1304                 } else {
1305                         evacuate_block_obj_sizes [i] = FALSE;
1306                 }
1307 #ifdef SGEN_HAVE_CONCURRENT_MARK
1308                 {
1309                         mword total_bytes = block_obj_sizes [i] * slots_available [i];
1310                         total_evacuate_heap += total_bytes;
1311                         if (evacuate_block_obj_sizes [i])
1312                                 total_evacuate_saved += total_bytes - block_obj_sizes [i] * slots_used [i];
1313                 }
1314 #endif
1315         }
1316
1317 #ifdef SGEN_HAVE_CONCURRENT_MARK
1318         want_evacuation = (float)total_evacuate_saved / (float)total_evacuate_heap > (1 - concurrent_evacuation_threshold);
1319 #endif
1320
1321         have_swept = TRUE;
1322 }
1323
1324 static void
1325 major_sweep (void)
1326 {
1327         ms_sweep ();
1328 }
1329
1330 static int count_pinned_ref;
1331 static int count_pinned_nonref;
1332 static int count_nonpinned_ref;
1333 static int count_nonpinned_nonref;
1334
1335 static void
1336 count_nonpinned_callback (char *obj, size_t size, void *data)
1337 {
1338         MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
1339
1340         if (vtable->klass->has_references)
1341                 ++count_nonpinned_ref;
1342         else
1343                 ++count_nonpinned_nonref;
1344 }
1345
1346 static void
1347 count_pinned_callback (char *obj, size_t size, void *data)
1348 {
1349         MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
1350
1351         if (vtable->klass->has_references)
1352                 ++count_pinned_ref;
1353         else
1354                 ++count_pinned_nonref;
1355 }
1356
1357 static G_GNUC_UNUSED void
1358 count_ref_nonref_objs (void)
1359 {
1360         int total;
1361
1362         count_pinned_ref = 0;
1363         count_pinned_nonref = 0;
1364         count_nonpinned_ref = 0;
1365         count_nonpinned_nonref = 0;
1366
1367         major_iterate_objects (ITERATE_OBJECTS_SWEEP_NON_PINNED, count_nonpinned_callback, NULL);
1368         major_iterate_objects (ITERATE_OBJECTS_SWEEP_PINNED, count_pinned_callback, NULL);
1369
1370         total = count_pinned_nonref + count_nonpinned_nonref + count_pinned_ref + count_nonpinned_ref;
1371
1372         g_print ("ref: %d pinned %d non-pinned   non-ref: %d pinned %d non-pinned  --  %.1f\n",
1373                         count_pinned_ref, count_nonpinned_ref,
1374                         count_pinned_nonref, count_nonpinned_nonref,
1375                         (count_pinned_nonref + count_nonpinned_nonref) * 100.0 / total);
1376 }
1377
1378 static int
1379 ms_calculate_block_obj_sizes (double factor, int *arr)
1380 {
1381         double target_size = sizeof (MonoObject);
1382         int num_sizes = 0;
1383         int last_size = 0;
1384
1385         do {
1386                 int target_count = (int)ceil (MS_BLOCK_FREE / target_size);
1387                 int size = MIN ((MS_BLOCK_FREE / target_count) & ~(SGEN_ALLOC_ALIGN - 1), SGEN_MAX_SMALL_OBJ_SIZE);
1388
1389                 if (size != last_size) {
1390                         if (arr)
1391                                 arr [num_sizes] = size;
1392                         ++num_sizes;
1393                         last_size = size;
1394                 }
1395
1396                 target_size *= factor;
1397         } while (last_size < SGEN_MAX_SMALL_OBJ_SIZE);
1398
1399         return num_sizes;
1400 }
1401
1402 /* only valid during minor collections */
1403 static mword old_num_major_sections;
1404
1405 static void
1406 major_start_nursery_collection (void)
1407 {
1408 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1409         consistency_check ();
1410 #endif
1411
1412         old_num_major_sections = num_major_sections;
1413 }
1414
1415 static void
1416 major_finish_nursery_collection (void)
1417 {
1418 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1419         consistency_check ();
1420 #endif
1421         sgen_register_major_sections_alloced (num_major_sections - old_num_major_sections);
1422 }
1423
1424 static void
1425 major_start_major_collection (void)
1426 {
1427         int i;
1428
1429         /* clear the free lists */
1430         for (i = 0; i < num_block_obj_sizes; ++i) {
1431                 if (!evacuate_block_obj_sizes [i])
1432                         continue;
1433
1434                 free_block_lists [0][i] = NULL;
1435                 free_block_lists [MS_BLOCK_FLAG_REFS][i] = NULL;
1436         }
1437
1438         // Sweep all unswept blocks
1439         if (lazy_sweep) {
1440                 MSBlockInfo *block;
1441
1442                 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, TRUE);
1443
1444                 FOREACH_BLOCK (block) {
1445                         sweep_block (block, TRUE);
1446                 } END_FOREACH_BLOCK;
1447
1448                 MONO_GC_SWEEP_END (GENERATION_OLD, TRUE);
1449         }
1450 }
1451
1452 static void
1453 major_finish_major_collection (void)
1454 {
1455 }
1456
1457 #if SIZEOF_VOID_P != 8
1458 static int
1459 compare_pointers (const void *va, const void *vb) {
1460         char *a = *(char**)va, *b = *(char**)vb;
1461         if (a < b)
1462                 return -1;
1463         if (a > b)
1464                 return 1;
1465         return 0;
1466 }
1467 #endif
1468
1469 static void
1470 major_have_computer_minor_collection_allowance (void)
1471 {
1472         size_t section_reserve = sgen_get_minor_collection_allowance () / MS_BLOCK_SIZE;
1473
1474         g_assert (have_swept);
1475
1476 #if SIZEOF_VOID_P != 8
1477         {
1478                 int i, num_empty_blocks_orig, num_blocks, arr_length;
1479                 void *block;
1480                 void **empty_block_arr;
1481                 void **rebuild_next;
1482
1483 #ifdef TARGET_WIN32
1484                 /*
1485                  * sgen_free_os_memory () asserts in mono_vfree () because windows doesn't like freeing the middle of
1486                  * a VirtualAlloc ()-ed block.
1487                  */
1488                 return;
1489 #endif
1490
1491                 if (num_empty_blocks <= section_reserve)
1492                         return;
1493                 SGEN_ASSERT (0, num_empty_blocks > 0, "section reserve can't be negative");
1494
1495                 num_empty_blocks_orig = num_empty_blocks;
1496                 empty_block_arr = (void**)sgen_alloc_internal_dynamic (sizeof (void*) * num_empty_blocks_orig,
1497                                 INTERNAL_MEM_MS_BLOCK_INFO_SORT, FALSE);
1498                 if (!empty_block_arr)
1499                         goto fallback;
1500
1501                 i = 0;
1502                 for (block = empty_blocks; block; block = *(void**)block)
1503                         empty_block_arr [i++] = block;
1504                 SGEN_ASSERT (0, i == num_empty_blocks, "empty block count wrong");
1505
1506                 sgen_qsort (empty_block_arr, num_empty_blocks, sizeof (void*), compare_pointers);
1507
1508                 /*
1509                  * We iterate over the free blocks, trying to find MS_BLOCK_ALLOC_NUM
1510                  * contiguous ones.  If we do, we free them.  If that's not enough to get to
1511                  * section_reserve, we halve the number of contiguous blocks we're looking
1512                  * for and have another go, until we're done with looking for pairs of
1513                  * blocks, at which point we give up and go to the fallback.
1514                  */
1515                 arr_length = num_empty_blocks_orig;
1516                 num_blocks = MS_BLOCK_ALLOC_NUM;
1517                 while (num_empty_blocks > section_reserve && num_blocks > 1) {
1518                         int first = -1;
1519                         int dest = 0;
1520
1521                         dest = 0;
1522                         for (i = 0; i < arr_length; ++i) {
1523                                 int d = dest;
1524                                 void *block = empty_block_arr [i];
1525                                 SGEN_ASSERT (0, block, "we're not shifting correctly");
1526                                 if (i != dest) {
1527                                         empty_block_arr [dest] = block;
1528                                         /*
1529                                          * This is not strictly necessary, but we're
1530                                          * cautious.
1531                                          */
1532                                         empty_block_arr [i] = NULL;
1533                                 }
1534                                 ++dest;
1535
1536                                 if (first < 0) {
1537                                         first = d;
1538                                         continue;
1539                                 }
1540
1541                                 SGEN_ASSERT (0, first >= 0 && d > first, "algorithm is wrong");
1542
1543                                 if ((char*)block != ((char*)empty_block_arr [d-1]) + MS_BLOCK_SIZE) {
1544                                         first = d;
1545                                         continue;
1546                                 }
1547
1548                                 if (d + 1 - first == num_blocks) {
1549                                         /*
1550                                          * We found num_blocks contiguous blocks.  Free them
1551                                          * and null their array entries.  As an optimization
1552                                          * we could, instead of nulling the entries, shift
1553                                          * the following entries over to the left, while
1554                                          * we're iterating.
1555                                          */
1556                                         int j;
1557                                         sgen_free_os_memory (empty_block_arr [first], MS_BLOCK_SIZE * num_blocks, SGEN_ALLOC_HEAP);
1558                                         for (j = first; j <= d; ++j)
1559                                                 empty_block_arr [j] = NULL;
1560                                         dest = first;
1561                                         first = -1;
1562
1563                                         num_empty_blocks -= num_blocks;
1564
1565                                         stat_major_blocks_freed += num_blocks;
1566                                         if (num_blocks == MS_BLOCK_ALLOC_NUM)
1567                                                 stat_major_blocks_freed_ideal += num_blocks;
1568                                         else
1569                                                 stat_major_blocks_freed_less_ideal += num_blocks;
1570
1571                                 }
1572                         }
1573
1574                         SGEN_ASSERT (0, dest <= i && dest <= arr_length, "array length is off");
1575                         arr_length = dest;
1576                         SGEN_ASSERT (0, arr_length == num_empty_blocks, "array length is off");
1577
1578                         num_blocks >>= 1;
1579                 }
1580
1581                 /* rebuild empty_blocks free list */
1582                 rebuild_next = (void**)&empty_blocks;
1583                 for (i = 0; i < arr_length; ++i) {
1584                         void *block = empty_block_arr [i];
1585                         SGEN_ASSERT (0, block, "we're missing blocks");
1586                         *rebuild_next = block;
1587                         rebuild_next = (void**)block;
1588                 }
1589                 *rebuild_next = NULL;
1590
1591                 /* free array */
1592                 sgen_free_internal_dynamic (empty_block_arr, sizeof (void*) * num_empty_blocks_orig, INTERNAL_MEM_MS_BLOCK_INFO_SORT);
1593         }
1594
1595         SGEN_ASSERT (0, num_empty_blocks >= 0, "we freed more blocks than we had in the first place?");
1596
1597  fallback:
1598         /*
1599          * This is our threshold.  If there's not more empty than used blocks, we won't
1600          * release uncontiguous blocks, in fear of fragmenting the address space.
1601          */
1602         if (num_empty_blocks <= num_major_sections)
1603                 return;
1604 #endif
1605
1606         while (num_empty_blocks > section_reserve) {
1607                 void *next = *(void**)empty_blocks;
1608                 sgen_free_os_memory (empty_blocks, MS_BLOCK_SIZE, SGEN_ALLOC_HEAP);
1609                 empty_blocks = next;
1610                 /*
1611                  * Needs not be atomic because this is running
1612                  * single-threaded.
1613                  */
1614                 --num_empty_blocks;
1615
1616                 ++stat_major_blocks_freed;
1617 #if SIZEOF_VOID_P != 8
1618                 ++stat_major_blocks_freed_individual;
1619 #endif
1620         }
1621 }
1622
1623 static void
1624 major_find_pin_queue_start_ends (SgenGrayQueue *queue)
1625 {
1626         MSBlockInfo *block;
1627
1628         FOREACH_BLOCK (block) {
1629                 block->pin_queue_start = sgen_find_optimized_pin_queue_area (MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SKIP, MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE,
1630                                 &block->pin_queue_num_entries);
1631         } END_FOREACH_BLOCK;
1632 }
1633
1634 static void
1635 major_pin_objects (SgenGrayQueue *queue)
1636 {
1637         MSBlockInfo *block;
1638
1639         FOREACH_BLOCK (block) {
1640                 mark_pinned_objects_in_block (block, queue);
1641         } END_FOREACH_BLOCK;
1642 }
1643
1644 static void
1645 major_init_to_space (void)
1646 {
1647 }
1648
1649 static void
1650 major_report_pinned_memory_usage (void)
1651 {
1652         g_assert_not_reached ();
1653 }
1654
1655 static gint64
1656 major_get_used_size (void)
1657 {
1658         gint64 size = 0;
1659         MSBlockInfo *block;
1660
1661         FOREACH_BLOCK (block) {
1662                 int count = MS_BLOCK_FREE / block->obj_size;
1663                 void **iter;
1664                 size += count * block->obj_size;
1665                 for (iter = block->free_list; iter; iter = (void**)*iter)
1666                         size -= block->obj_size;
1667         } END_FOREACH_BLOCK;
1668
1669         return size;
1670 }
1671
1672 static size_t
1673 get_num_major_sections (void)
1674 {
1675         return num_major_sections;
1676 }
1677
1678 static gboolean
1679 major_handle_gc_param (const char *opt)
1680 {
1681         if (g_str_has_prefix (opt, "evacuation-threshold=")) {
1682                 const char *arg = strchr (opt, '=') + 1;
1683                 int percentage = atoi (arg);
1684                 if (percentage < 0 || percentage > 100) {
1685                         fprintf (stderr, "evacuation-threshold must be an integer in the range 0-100.\n");
1686                         exit (1);
1687                 }
1688                 evacuation_threshold = (float)percentage / 100.0f;
1689                 return TRUE;
1690         } else if (!strcmp (opt, "lazy-sweep")) {
1691                 lazy_sweep = TRUE;
1692                 return TRUE;
1693         } else if (!strcmp (opt, "no-lazy-sweep")) {
1694                 lazy_sweep = FALSE;
1695                 return TRUE;
1696         }
1697
1698         return FALSE;
1699 }
1700
1701 static void
1702 major_print_gc_param_usage (void)
1703 {
1704         fprintf (stderr,
1705                         ""
1706                         "  evacuation-threshold=P (where P is a percentage, an integer in 0-100)\n"
1707                         "  (no-)lazy-sweep\n"
1708                         );
1709 }
1710
1711 static void
1712 major_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
1713 {
1714         MSBlockInfo *block;
1715         gboolean has_references;
1716
1717         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1718                 if (has_references)
1719                         callback ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE);
1720         } END_FOREACH_BLOCK;
1721 }
1722
1723 #ifdef HEAVY_STATISTICS
1724 extern long long marked_cards;
1725 extern long long scanned_cards;
1726 extern long long scanned_objects;
1727 extern long long remarked_cards;
1728 #endif
1729
1730 #define CARD_WORDS_PER_BLOCK (CARDS_PER_BLOCK / SIZEOF_VOID_P)
1731 /*
1732  * MS blocks are 16K aligned.
1733  * Cardtables are 4K aligned, at least.
1734  * This means that the cardtable of a given block is 32 bytes aligned.
1735  */
1736 static guint8*
1737 initial_skip_card (guint8 *card_data)
1738 {
1739         mword *cards = (mword*)card_data;
1740         mword card;
1741         int i;
1742         for (i = 0; i < CARD_WORDS_PER_BLOCK; ++i) {
1743                 card = cards [i];
1744                 if (card)
1745                         break;
1746         }
1747
1748         if (i == CARD_WORDS_PER_BLOCK)
1749                 return card_data + CARDS_PER_BLOCK;
1750
1751 #if defined(__i386__) && defined(__GNUC__)
1752         return card_data + i * 4 +  (__builtin_ffs (card) - 1) / 8;
1753 #elif defined(__x86_64__) && defined(__GNUC__)
1754         return card_data + i * 8 +  (__builtin_ffsll (card) - 1) / 8;
1755 #elif defined(__s390x__) && defined(__GNUC__)
1756         return card_data + i * 8 +  (__builtin_ffsll (GUINT64_TO_LE(card)) - 1) / 8;
1757 #else
1758         for (i = i * SIZEOF_VOID_P; i < CARDS_PER_BLOCK; ++i) {
1759                 if (card_data [i])
1760                         return &card_data [i];
1761         }
1762         return card_data;
1763 #endif
1764 }
1765
1766
1767 static G_GNUC_UNUSED guint8*
1768 skip_card (guint8 *card_data, guint8 *card_data_end)
1769 {
1770         while (card_data < card_data_end && !*card_data)
1771                 ++card_data;
1772         return card_data;
1773 }
1774
1775 #define MS_BLOCK_OBJ_INDEX_FAST(o,b,os) (((char*)(o) - ((b) + MS_BLOCK_SKIP)) / (os))
1776 #define MS_BLOCK_OBJ_FAST(b,os,i)                       ((b) + MS_BLOCK_SKIP + (os) * (i))
1777 #define MS_OBJ_ALLOCED_FAST(o,b)                (*(void**)(o) && (*(char**)(o) < (b) || *(char**)(o) >= (b) + MS_BLOCK_SIZE))
1778
1779 static void
1780 major_scan_card_table (gboolean mod_union, SgenGrayQueue *queue)
1781 {
1782         MSBlockInfo *block;
1783         gboolean has_references;
1784         ScanObjectFunc scan_func = sgen_get_current_object_ops ()->scan_object;
1785
1786 #ifdef SGEN_HAVE_CONCURRENT_MARK
1787         if (!concurrent_mark)
1788                 g_assert (!mod_union);
1789 #else
1790         g_assert (!mod_union);
1791 #endif
1792
1793         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1794                 int block_obj_size;
1795                 char *block_start;
1796
1797                 if (!has_references)
1798                         continue;
1799
1800                 block_obj_size = block->obj_size;
1801                 block_start = MS_BLOCK_FOR_BLOCK_INFO (block);
1802
1803                 if (block_obj_size >= CARD_SIZE_IN_BYTES) {
1804                         guint8 *cards;
1805 #ifndef SGEN_HAVE_OVERLAPPING_CARDS
1806                         guint8 cards_data [CARDS_PER_BLOCK];
1807 #endif
1808                         char *obj, *end, *base;
1809
1810                         if (mod_union) {
1811 #ifdef SGEN_HAVE_CONCURRENT_MARK
1812                                 cards = block->cardtable_mod_union;
1813                                 /*
1814                                  * This happens when the nursery
1815                                  * collection that precedes finishing
1816                                  * the concurrent collection allocates
1817                                  * new major blocks.
1818                                  */
1819                                 if (!cards)
1820                                         continue;
1821 #endif
1822                         } else {
1823                         /*We can avoid the extra copy since the remark cardtable was cleaned before */
1824 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
1825                                 cards = sgen_card_table_get_card_scan_address ((mword)block_start);
1826 #else
1827                                 cards = cards_data;
1828                                 if (!sgen_card_table_get_card_data (cards_data, (mword)block_start, CARDS_PER_BLOCK))
1829                                         continue;
1830 #endif
1831                         }
1832
1833                         obj = (char*)MS_BLOCK_OBJ_FAST (block_start, block_obj_size, 0);
1834                         end = block_start + MS_BLOCK_SIZE;
1835                         base = sgen_card_table_align_pointer (obj);
1836
1837                         while (obj < end) {
1838                                 size_t card_offset;
1839
1840                                 if (!block->swept)
1841                                         sweep_block (block, FALSE);
1842
1843                                 if (!MS_OBJ_ALLOCED_FAST (obj, block_start))
1844                                         goto next_large;
1845
1846                                 if (mod_union) {
1847                                         /* FIXME: do this more efficiently */
1848                                         int w, b;
1849                                         MS_CALC_MARK_BIT (w, b, obj);
1850                                         if (!MS_MARK_BIT (block, w, b))
1851                                                 goto next_large;
1852                                 }
1853
1854                                 card_offset = (obj - base) >> CARD_BITS;
1855                                 sgen_cardtable_scan_object (obj, block_obj_size, cards + card_offset, mod_union, queue);
1856
1857                         next_large:
1858                                 obj += block_obj_size;
1859                         }
1860                 } else {
1861                         guint8 *card_data, *card_base;
1862                         guint8 *card_data_end;
1863
1864                         /*
1865                          * This is safe in face of card aliasing for the following reason:
1866                          *
1867                          * Major blocks are 16k aligned, or 32 cards aligned.
1868                          * Cards aliasing happens in powers of two, so as long as major blocks are aligned to their
1869                          * sizes, they won't overflow the cardtable overlap modulus.
1870                          */
1871                         if (mod_union) {
1872 #ifdef SGEN_HAVE_CONCURRENT_MARK
1873                                 card_data = card_base = block->cardtable_mod_union;
1874                                 /*
1875                                  * This happens when the nursery
1876                                  * collection that precedes finishing
1877                                  * the concurrent collection allocates
1878                                  * new major blocks.
1879                                  */
1880                                 if (!card_data)
1881                                         continue;
1882 #else
1883                                 g_assert_not_reached ();
1884                                 card_data = NULL;
1885 #endif
1886                         } else {
1887                                 card_data = card_base = sgen_card_table_get_card_scan_address ((mword)block_start);
1888                         }
1889                         card_data_end = card_data + CARDS_PER_BLOCK;
1890
1891                         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)) {
1892                                 size_t index;
1893                                 size_t idx = card_data - card_base;
1894                                 char *start = (char*)(block_start + idx * CARD_SIZE_IN_BYTES);
1895                                 char *end = start + CARD_SIZE_IN_BYTES;
1896                                 char *first_obj, *obj;
1897
1898                                 HEAVY_STAT (++scanned_cards);
1899
1900                                 if (!*card_data)
1901                                         continue;
1902
1903                                 if (!block->swept)
1904                                         sweep_block (block, FALSE);
1905
1906                                 HEAVY_STAT (++marked_cards);
1907
1908                                 sgen_card_table_prepare_card_for_scanning (card_data);
1909
1910                                 if (idx == 0)
1911                                         index = 0;
1912                                 else
1913                                         index = MS_BLOCK_OBJ_INDEX_FAST (start, block_start, block_obj_size);
1914
1915                                 obj = first_obj = (char*)MS_BLOCK_OBJ_FAST (block_start, block_obj_size, index);
1916                                 while (obj < end) {
1917                                         if (!MS_OBJ_ALLOCED_FAST (obj, block_start))
1918                                                 goto next_small;
1919
1920                                         if (mod_union) {
1921                                                 /* FIXME: do this more efficiently */
1922                                                 int w, b;
1923                                                 MS_CALC_MARK_BIT (w, b, obj);
1924                                                 if (!MS_MARK_BIT (block, w, b))
1925                                                         goto next_small;
1926                                         }
1927
1928                                         HEAVY_STAT (++scanned_objects);
1929                                         scan_func (obj, sgen_obj_get_descriptor (obj), queue);
1930                                 next_small:
1931                                         obj += block_obj_size;
1932                                 }
1933                                 HEAVY_STAT (if (*card_data) ++remarked_cards);
1934                                 binary_protocol_card_scan (first_obj, obj - first_obj);
1935                         }
1936                 }
1937         } END_FOREACH_BLOCK;
1938 }
1939
1940 static void
1941 major_count_cards (long long *num_total_cards, long long *num_marked_cards)
1942 {
1943         MSBlockInfo *block;
1944         gboolean has_references;
1945         long long total_cards = 0;
1946         long long marked_cards = 0;
1947
1948         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1949                 guint8 *cards = sgen_card_table_get_card_scan_address ((mword) MS_BLOCK_FOR_BLOCK_INFO (block));
1950                 int i;
1951
1952                 if (!has_references)
1953                         continue;
1954
1955                 total_cards += CARDS_PER_BLOCK;
1956                 for (i = 0; i < CARDS_PER_BLOCK; ++i) {
1957                         if (cards [i])
1958                                 ++marked_cards;
1959                 }
1960         } END_FOREACH_BLOCK;
1961
1962         *num_total_cards = total_cards;
1963         *num_marked_cards = marked_cards;
1964 }
1965
1966 #ifdef SGEN_HAVE_CONCURRENT_MARK
1967 static void
1968 update_cardtable_mod_union (void)
1969 {
1970         MSBlockInfo *block;
1971
1972         FOREACH_BLOCK (block) {
1973                 size_t num_cards;
1974
1975                 block->cardtable_mod_union = sgen_card_table_update_mod_union (block->cardtable_mod_union,
1976                                 MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE, &num_cards);
1977
1978                 SGEN_ASSERT (0, num_cards == CARDS_PER_BLOCK, "Number of cards calculation is wrong");
1979         } END_FOREACH_BLOCK;
1980 }
1981
1982 static guint8*
1983 major_get_cardtable_mod_union_for_object (char *obj)
1984 {
1985         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
1986         return &block->cardtable_mod_union [(obj - (char*)sgen_card_table_align_pointer (MS_BLOCK_FOR_BLOCK_INFO (block))) >> CARD_BITS];
1987 }
1988 #endif
1989
1990 static void
1991 alloc_free_block_lists (MSBlockInfo ***lists)
1992 {
1993         int i;
1994         for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i)
1995                 lists [i] = sgen_alloc_internal_dynamic (sizeof (MSBlockInfo*) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
1996 }
1997
1998 #undef pthread_create
1999
2000 static void
2001 post_param_init (SgenMajorCollector *collector)
2002 {
2003         collector->sweeps_lazily = lazy_sweep;
2004 }
2005
2006 #ifdef SGEN_HAVE_CONCURRENT_MARK
2007 static void
2008 sgen_marksweep_init_internal (SgenMajorCollector *collector, gboolean is_concurrent)
2009 #else // SGEN_HAVE_CONCURRENT_MARK
2010 #error unknown configuration
2011 #endif // SGEN_HAVE_CONCURRENT_MARK
2012 {
2013         int i;
2014
2015         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_MS_BLOCK_INFO, sizeof (MSBlockInfo));
2016
2017         num_block_obj_sizes = ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, NULL);
2018         block_obj_sizes = sgen_alloc_internal_dynamic (sizeof (int) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2019         ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, block_obj_sizes);
2020
2021         evacuate_block_obj_sizes = sgen_alloc_internal_dynamic (sizeof (gboolean) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2022         for (i = 0; i < num_block_obj_sizes; ++i)
2023                 evacuate_block_obj_sizes [i] = FALSE;
2024
2025         /*
2026         {
2027                 int i;
2028                 g_print ("block object sizes:\n");
2029                 for (i = 0; i < num_block_obj_sizes; ++i)
2030                         g_print ("%d\n", block_obj_sizes [i]);
2031         }
2032         */
2033
2034         alloc_free_block_lists (free_block_lists);
2035
2036         for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES; ++i)
2037                 fast_block_obj_size_indexes [i] = ms_find_block_obj_size_index (i * 8);
2038         for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES * 8; ++i)
2039                 g_assert (MS_BLOCK_OBJ_SIZE_INDEX (i) == ms_find_block_obj_size_index (i));
2040
2041         mono_counters_register ("# major blocks allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_alloced);
2042         mono_counters_register ("# major blocks freed", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed);
2043         mono_counters_register ("# major blocks lazy swept", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_lazy_swept);
2044         mono_counters_register ("# major objects evacuated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_objects_evacuated);
2045 #if SIZEOF_VOID_P != 8
2046         mono_counters_register ("# major blocks freed ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_ideal);
2047         mono_counters_register ("# major blocks freed less ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_less_ideal);
2048         mono_counters_register ("# major blocks freed individually", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_individual);
2049         mono_counters_register ("# major blocks allocated less ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_alloced_less_ideal);
2050 #endif
2051
2052         collector->section_size = MAJOR_SECTION_SIZE;
2053
2054 #ifdef SGEN_HAVE_CONCURRENT_MARK
2055         concurrent_mark = is_concurrent;
2056         if (is_concurrent) {
2057                 collector->is_concurrent = TRUE;
2058                 collector->want_synchronous_collection = &want_evacuation;
2059         } else
2060 #endif
2061         {
2062                 collector->is_concurrent = FALSE;
2063                 collector->want_synchronous_collection = NULL;
2064         }
2065         collector->get_and_reset_num_major_objects_marked = major_get_and_reset_num_major_objects_marked;
2066         collector->supports_cardtable = TRUE;
2067
2068         collector->have_swept = &have_swept;
2069
2070         collector->alloc_heap = major_alloc_heap;
2071         collector->is_object_live = major_is_object_live;
2072         collector->alloc_small_pinned_obj = major_alloc_small_pinned_obj;
2073         collector->alloc_degraded = major_alloc_degraded;
2074
2075         collector->alloc_object = major_alloc_object;
2076         collector->free_pinned_object = free_pinned_object;
2077         collector->iterate_objects = major_iterate_objects;
2078         collector->free_non_pinned_object = major_free_non_pinned_object;
2079         collector->find_pin_queue_start_ends = major_find_pin_queue_start_ends;
2080         collector->pin_objects = major_pin_objects;
2081         collector->pin_major_object = pin_major_object;
2082         collector->scan_card_table = major_scan_card_table;
2083         collector->iterate_live_block_ranges = (void*)(void*) major_iterate_live_block_ranges;
2084 #ifdef SGEN_HAVE_CONCURRENT_MARK
2085         if (is_concurrent) {
2086                 collector->update_cardtable_mod_union = update_cardtable_mod_union;
2087                 collector->get_cardtable_mod_union_for_object = major_get_cardtable_mod_union_for_object;
2088         }
2089 #endif
2090         collector->init_to_space = major_init_to_space;
2091         collector->sweep = major_sweep;
2092         collector->check_scan_starts = major_check_scan_starts;
2093         collector->dump_heap = major_dump_heap;
2094         collector->get_used_size = major_get_used_size;
2095         collector->start_nursery_collection = major_start_nursery_collection;
2096         collector->finish_nursery_collection = major_finish_nursery_collection;
2097         collector->start_major_collection = major_start_major_collection;
2098         collector->finish_major_collection = major_finish_major_collection;
2099         collector->have_computed_minor_collection_allowance = major_have_computer_minor_collection_allowance;
2100         collector->ptr_is_in_non_pinned_space = major_ptr_is_in_non_pinned_space;
2101         collector->obj_is_from_pinned_alloc = obj_is_from_pinned_alloc;
2102         collector->report_pinned_memory_usage = major_report_pinned_memory_usage;
2103         collector->get_num_major_sections = get_num_major_sections;
2104         collector->handle_gc_param = major_handle_gc_param;
2105         collector->print_gc_param_usage = major_print_gc_param_usage;
2106         collector->post_param_init = post_param_init;
2107         collector->is_valid_object = major_is_valid_object;
2108         collector->describe_pointer = major_describe_pointer;
2109         collector->count_cards = major_count_cards;
2110
2111         collector->major_ops.copy_or_mark_object = major_copy_or_mark_object_canonical;
2112         collector->major_ops.scan_object = major_scan_object;
2113 #ifdef SGEN_HAVE_CONCURRENT_MARK
2114         if (is_concurrent) {
2115                 collector->major_concurrent_ops.copy_or_mark_object = major_copy_or_mark_object_concurrent_canonical;
2116                 collector->major_concurrent_ops.scan_object = major_scan_object_concurrent;
2117                 collector->major_concurrent_ops.scan_vtype = major_scan_vtype_concurrent;
2118         }
2119 #endif
2120
2121         /*cardtable requires major pages to be 8 cards aligned*/
2122         g_assert ((MS_BLOCK_SIZE % (8 * CARD_SIZE_IN_BYTES)) == 0);
2123 }
2124
2125 #ifdef SGEN_HAVE_CONCURRENT_MARK
2126 void
2127 sgen_marksweep_init (SgenMajorCollector *collector)
2128 {
2129         sgen_marksweep_init_internal (collector, FALSE);
2130 }
2131
2132 void
2133 sgen_marksweep_conc_init (SgenMajorCollector *collector)
2134 {
2135         sgen_marksweep_init_internal (collector, TRUE);
2136 }
2137 #endif
2138
2139 #endif