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
  46 #define SGEN_HAVE_CONCURRENT_MARK
  47
  48 #define MS_BLOCK_SIZE   (16*1024)
  49 #define MS_BLOCK_SIZE_SHIFT     14
  50 #define MAJOR_SECTION_SIZE      MS_BLOCK_SIZE
  51 #define CARDS_PER_BLOCK (MS_BLOCK_SIZE / CARD_SIZE_IN_BYTES)
  52
  53 /*
  54  * Don't allocate single blocks, but alloc a contingent of this many
  55  * blocks in one swoop.  This must be a power of two.
  56  */
  57 #define MS_BLOCK_ALLOC_NUM      32
  58
  59 /*
  60  * Number of bytes before the first object in a block.  At the start
  61  * of a block is the MSBlockHeader, then opional padding, then come
  62  * the objects, so this must be >= sizeof (MSBlockHeader).
  63  */
  64 #define MS_BLOCK_SKIP   16
  65
  66 #define MS_BLOCK_FREE   (MS_BLOCK_SIZE - MS_BLOCK_SKIP)
  67
  68 #define MS_NUM_MARK_WORDS       ((MS_BLOCK_SIZE / SGEN_ALLOC_ALIGN + sizeof (mword) * 8 - 1) / (sizeof (mword) * 8))
  69
  70 #if SGEN_MAX_SMALL_OBJ_SIZE > MS_BLOCK_FREE / 2
  71 #error MAX_SMALL_OBJ_SIZE must be at most MS_BLOCK_FREE / 2
  72 #endif
  73
  74 typedef struct _MSBlockInfo MSBlockInfo;
  75 struct _MSBlockInfo {
  76         int obj_size;
  77         int obj_size_index;
  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         size_t pin_queue_first_entry;
  87         size_t pin_queue_last_entry;
  88 #ifdef SGEN_HAVE_CONCURRENT_MARK
  89         guint8 *cardtable_mod_union;
  90 #endif
  91         mword mark_words [MS_NUM_MARK_WORDS];
  92 };
  93
  94 #define MS_BLOCK_FOR_BLOCK_INFO(b)      ((b)->block)
  95
  96 #define MS_BLOCK_OBJ(b,i)               (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (b)->obj_size * (i))
  97 #define MS_BLOCK_OBJ_FOR_SIZE(b,i,obj_size)             (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP + (obj_size) * (i))
  98 #define MS_BLOCK_DATA_FOR_OBJ(o)        ((char*)((mword)(o) & ~(mword)(MS_BLOCK_SIZE - 1)))
  99
 100 typedef struct {
 101         MSBlockInfo *info;
 102 } MSBlockHeader;
 103
 104 #define MS_BLOCK_FOR_OBJ(o)             (((MSBlockHeader*)MS_BLOCK_DATA_FOR_OBJ ((o)))->info)
 105
 106 /* object index will always be small */
 107 #define MS_BLOCK_OBJ_INDEX(o,b) ((int)(((char*)(o) - (MS_BLOCK_FOR_BLOCK_INFO(b) + MS_BLOCK_SKIP)) / (b)->obj_size))
 108
 109 //casting to int is fine since blocks are 32k
 110 #define MS_CALC_MARK_BIT(w,b,o)         do {                            \
 111                 int i = ((int)((char*)(o) - MS_BLOCK_DATA_FOR_OBJ ((o)))) >> SGEN_ALLOC_ALIGN_BITS; \
 112                 if (sizeof (mword) == 4) {                              \
 113                         (w) = i >> 5;                                   \
 114                         (b) = i & 31;                                   \
 115                 } else {                                                \
 116                         (w) = i >> 6;                                   \
 117                         (b) = i & 63;                                   \
 118                 }                                                       \
 119         } while (0)
 120
 121 #define MS_MARK_BIT(bl,w,b)     ((bl)->mark_words [(w)] & (ONE_P << (b)))
 122 #define MS_SET_MARK_BIT(bl,w,b) ((bl)->mark_words [(w)] |= (ONE_P << (b)))
 123 #define MS_PAR_SET_MARK_BIT(was_marked,bl,w,b)  do {                    \
 124                 mword __old = (bl)->mark_words [(w)];                   \
 125                 mword __bitmask = ONE_P << (b);                         \
 126                 if (__old & __bitmask) {                                \
 127                         was_marked = TRUE;                              \
 128                         break;                                          \
 129                 }                                                       \
 130                 if (SGEN_CAS_PTR ((gpointer*)&(bl)->mark_words [(w)],   \
 131                                                 (gpointer)(__old | __bitmask), \
 132                                                 (gpointer)__old) ==     \
 133                                 (gpointer)__old) {                      \
 134                         was_marked = FALSE;                             \
 135                         break;                                          \
 136                 }                                                       \
 137         } while (1)
 138
 139 #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))
 140
 141 #define MS_BLOCK_OBJ_SIZE_FACTOR        (sqrt (2.0))
 142
 143 /*
 144  * This way we can lookup block object size indexes for sizes up to
 145  * 256 bytes with a single load.
 146  */
 147 #define MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES      32
 148
 149 static int *block_obj_sizes;
 150 static int num_block_obj_sizes;
 151 static int fast_block_obj_size_indexes [MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES];
 152
 153 #define MS_BLOCK_FLAG_PINNED    1
 154 #define MS_BLOCK_FLAG_REFS      2
 155
 156 #define MS_BLOCK_TYPE_MAX       4
 157
 158 static gboolean *evacuate_block_obj_sizes;
 159 static float evacuation_threshold = 0.666f;
 160 #ifdef SGEN_HAVE_CONCURRENT_MARK
 161 static float concurrent_evacuation_threshold = 0.666f;
 162 static gboolean want_evacuation = FALSE;
 163 #endif
 164
 165 static gboolean lazy_sweep = TRUE;
 166 static gboolean have_swept;
 167
 168 #ifdef SGEN_HAVE_CONCURRENT_MARK
 169 static gboolean concurrent_mark;
 170 #endif
 171
 172 #define BLOCK_IS_TAGGED_HAS_REFERENCES(bl)      SGEN_POINTER_IS_TAGGED_1 ((bl))
 173 #define BLOCK_TAG_HAS_REFERENCES(bl)            SGEN_POINTER_TAG_1 ((bl))
 174 #define BLOCK_UNTAG_HAS_REFERENCES(bl)          SGEN_POINTER_UNTAG_1 ((bl))
 175
 176 #define BLOCK_TAG(bl)   ((bl)->has_references ? BLOCK_TAG_HAS_REFERENCES ((bl)) : (bl))
 177
 178 /* all allocated blocks in the system */
 179 static SgenPointerQueue allocated_blocks;
 180
 181 /* non-allocated block free-list */
 182 static void *empty_blocks = NULL;
 183 static size_t num_empty_blocks = 0;
 184
 185 #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]);
 186 #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));
 187 #define END_FOREACH_BLOCK       } }
 188 #define DELETE_BLOCK_IN_FOREACH()       (allocated_blocks.data [__index] = NULL)
 189
 190 static size_t num_major_sections = 0;
 191 /* one free block list for each block object size */
 192 static MSBlockInfo **free_block_lists [MS_BLOCK_TYPE_MAX];
 193
 194 static long long stat_major_blocks_alloced = 0;
 195 static long long stat_major_blocks_freed = 0;
 196 static long long stat_major_blocks_lazy_swept = 0;
 197 static long long stat_major_objects_evacuated = 0;
 198
 199 #if SIZEOF_VOID_P != 8
 200 static long long stat_major_blocks_freed_ideal = 0;
 201 static long long stat_major_blocks_freed_less_ideal = 0;
 202 static long long stat_major_blocks_freed_individual = 0;
 203 static long long stat_major_blocks_alloced_less_ideal = 0;
 204 #endif
 205
 206 #ifdef SGEN_COUNT_NUMBER_OF_MAJOR_OBJECTS_MARKED
 207 static long long num_major_objects_marked = 0;
 208 #define INC_NUM_MAJOR_OBJECTS_MARKED()  (++num_major_objects_marked)
 209 #else
 210 #define INC_NUM_MAJOR_OBJECTS_MARKED()
 211 #endif
 212
 213 static void
 214 sweep_block (MSBlockInfo *block, gboolean during_major_collection);
 215
 216 static int
 217 ms_find_block_obj_size_index (size_t size)
 218 {
 219         int i;
 220         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);
 221         for (i = 0; i < num_block_obj_sizes; ++i)
 222                 if (block_obj_sizes [i] >= size)
 223                         return i;
 224         g_error ("no object of size %d\n", size);
 225 }
 226
 227 #define FREE_BLOCKS_FROM(lists,p,r)     (lists [((p) ? MS_BLOCK_FLAG_PINNED : 0) | ((r) ? MS_BLOCK_FLAG_REFS : 0)])
 228 #define FREE_BLOCKS(p,r)                (FREE_BLOCKS_FROM (free_block_lists, (p), (r)))
 229
 230 #define MS_BLOCK_OBJ_SIZE_INDEX(s)                              \
 231         (((s)+7)>>3 < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES ?      \
 232          fast_block_obj_size_indexes [((s)+7)>>3] :             \
 233          ms_find_block_obj_size_index ((s)))
 234
 235 static void*
 236 major_alloc_heap (mword nursery_size, mword nursery_align, int the_nursery_bits)
 237 {
 238         char *start;
 239         if (nursery_align)
 240                 start = sgen_alloc_os_memory_aligned (nursery_size, nursery_align, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE, "nursery");
 241         else
 242                 start = sgen_alloc_os_memory (nursery_size, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE, "nursery");
 243
 244         return start;
 245 }
 246
 247 static void
 248 update_heap_boundaries_for_block (MSBlockInfo *block)
 249 {
 250         sgen_update_heap_boundaries ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), (mword)MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE);
 251 }
 252
 253 static void*
 254 ms_get_empty_block (void)
 255 {
 256         char *p;
 257         int i;
 258         void *block, *empty, *next;
 259
 260  retry:
 261         if (!empty_blocks) {
 262                 /*
 263                  * We try allocating MS_BLOCK_ALLOC_NUM blocks first.  If that's
 264                  * unsuccessful, we halve the number of blocks and try again, until we're at
 265                  * 1.  If that doesn't work, either, we assert.
 266                  */
 267                 int alloc_num = MS_BLOCK_ALLOC_NUM;
 268                 for (;;) {
 269                         p = sgen_alloc_os_memory_aligned (MS_BLOCK_SIZE * alloc_num, MS_BLOCK_SIZE, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE,
 270                                         alloc_num == 1 ? "major heap section" : NULL);
 271                         if (p)
 272                                 break;
 273                         alloc_num >>= 1;
 274                 }
 275
 276                 for (i = 0; i < alloc_num; ++i) {
 277                         block = p;
 278                         /*
 279                          * We do the free list update one after the
 280                          * other so that other threads can use the new
 281                          * blocks as quickly as possible.
 282                          */
 283                         do {
 284                                 empty = empty_blocks;
 285                                 *(void**)block = empty;
 286                         } while (SGEN_CAS_PTR ((gpointer*)&empty_blocks, block, empty) != empty);
 287                         p += MS_BLOCK_SIZE;
 288                 }
 289
 290                 SGEN_ATOMIC_ADD_P (num_empty_blocks, alloc_num);
 291
 292                 stat_major_blocks_alloced += alloc_num;
 293 #if SIZEOF_VOID_P != 8
 294                 if (alloc_num != MS_BLOCK_ALLOC_NUM)
 295                         stat_major_blocks_alloced_less_ideal += alloc_num;
 296 #endif
 297         }
 298
 299         do {
 300                 empty = empty_blocks;
 301                 if (!empty)
 302                         goto retry;
 303                 block = empty;
 304                 next = *(void**)block;
 305         } while (SGEN_CAS_PTR (&empty_blocks, next, empty) != empty);
 306
 307         SGEN_ATOMIC_ADD_P (num_empty_blocks, -1);
 308
 309         *(void**)block = NULL;
 310
 311         g_assert (!((mword)block & (MS_BLOCK_SIZE - 1)));
 312
 313         return block;
 314 }
 315
 316 static void
 317 ms_free_block (void *block)
 318 {
 319         void *empty;
 320
 321         sgen_memgov_release_space (MS_BLOCK_SIZE, SPACE_MAJOR);
 322         memset (block, 0, MS_BLOCK_SIZE);
 323
 324         do {
 325                 empty = empty_blocks;
 326                 *(void**)block = empty;
 327         } while (SGEN_CAS_PTR (&empty_blocks, block, empty) != empty);
 328
 329         SGEN_ATOMIC_ADD_P (num_empty_blocks, 1);
 330 }
 331
 332 //#define MARKSWEEP_CONSISTENCY_CHECK
 333
 334 #ifdef MARKSWEEP_CONSISTENCY_CHECK
 335 static void
 336 check_block_free_list (MSBlockInfo *block, int size, gboolean pinned)
 337 {
 338         MSBlockInfo *b;
 339
 340         for (; block; block = block->next_free) {
 341                 g_assert (block->obj_size == size);
 342                 g_assert ((pinned && block->pinned) || (!pinned && !block->pinned));
 343
 344                 /* blocks in the free lists must have at least
 345                    one free slot */
 346                 if (block->swept)
 347                         g_assert (block->free_list);
 348
 349                 /* the block must be in the allocated_blocks array */
 350                 g_assert (sgen_pointer_queue_find (&allocated_blocks, BLOCK_TAG (block)) != (size_t)-1);
 351         }
 352 }
 353
 354 static void
 355 check_empty_blocks (void)
 356 {
 357         void *p;
 358         size_t i = 0;
 359         for (p = empty_blocks; p; p = *(void**)p)
 360                 ++i;
 361         g_assert (i == num_empty_blocks);
 362 }
 363
 364 static void
 365 consistency_check (void)
 366 {
 367         MSBlockInfo *block;
 368         int i;
 369
 370         /* check all blocks */
 371         FOREACH_BLOCK (block) {
 372                 int count = MS_BLOCK_FREE / block->obj_size;
 373                 int num_free = 0;
 374                 void **free;
 375
 376                 /* check block header */
 377                 g_assert (((MSBlockHeader*)block->block)->info == block);
 378
 379                 /* count number of free slots */
 380                 for (i = 0; i < count; ++i) {
 381                         void **obj = (void**) MS_BLOCK_OBJ (block, i);
 382                         if (!MS_OBJ_ALLOCED (obj, block))
 383                                 ++num_free;
 384                 }
 385
 386                 /* check free list */
 387                 for (free = block->free_list; free; free = (void**)*free) {
 388                         g_assert (MS_BLOCK_FOR_OBJ (free) == block);
 389                         --num_free;
 390                 }
 391                 g_assert (num_free == 0);
 392
 393                 /* check all mark words are zero */
 394                 if (block->swept) {
 395                         for (i = 0; i < MS_NUM_MARK_WORDS; ++i)
 396                                 g_assert (block->mark_words [i] == 0);
 397                 }
 398         } END_FOREACH_BLOCK;
 399
 400         /* check free blocks */
 401         for (i = 0; i < num_block_obj_sizes; ++i) {
 402                 int j;
 403                 for (j = 0; j < MS_BLOCK_TYPE_MAX; ++j)
 404                         check_block_free_list (free_block_lists [j][i], block_obj_sizes [i], j & MS_BLOCK_FLAG_PINNED);
 405         }
 406
 407         check_empty_blocks ();
 408 }
 409 #endif
 410
 411 static gboolean
 412 ms_alloc_block (int size_index, gboolean pinned, gboolean has_references)
 413 {
 414         int size = block_obj_sizes [size_index];
 415         int count = MS_BLOCK_FREE / size;
 416         MSBlockInfo *info;
 417         MSBlockHeader *header;
 418         MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, has_references);
 419         char *obj_start;
 420         int i;
 421
 422         if (!sgen_memgov_try_alloc_space (MS_BLOCK_SIZE, SPACE_MAJOR))
 423                 return FALSE;
 424
 425         info = sgen_alloc_internal (INTERNAL_MEM_MS_BLOCK_INFO);
 426
 427         SGEN_ASSERT (9, count >= 2, "block with %d objects, it must hold at least 2", count);
 428
 429         info->obj_size = size;
 430         info->obj_size_index = size_index;
 431         info->pinned = pinned;
 432         info->has_references = has_references;
 433         info->has_pinned = pinned;
 434         /*
 435          * Blocks that are to-space are not evacuated from.  During an major collection
 436          * blocks are allocated for two reasons: evacuating objects from the nursery and
 437          * evacuating them from major blocks marked for evacuation.  In both cases we don't
 438          * want further evacuation.
 439          */
 440         info->is_to_space = (sgen_get_current_collection_generation () == GENERATION_OLD);
 441         info->swept = 1;
 442         info->block = ms_get_empty_block ();
 443
 444         header = (MSBlockHeader*) info->block;
 445         header->info = info;
 446 #ifdef SGEN_HAVE_CONCURRENT_MARK
 447         info->cardtable_mod_union = NULL;
 448 #endif
 449
 450         update_heap_boundaries_for_block (info);
 451
 452         /* build free list */
 453         obj_start = MS_BLOCK_FOR_BLOCK_INFO (info) + MS_BLOCK_SKIP;
 454         info->free_list = (void**)obj_start;
 455         /* we're skipping the last one - it must be nulled */
 456         for (i = 0; i < count - 1; ++i) {
 457                 char *next_obj_start = obj_start + size;
 458                 *(void**)obj_start = next_obj_start;
 459                 obj_start = next_obj_start;
 460         }
 461         /* the last one */
 462         *(void**)obj_start = NULL;
 463
 464         info->next_free = free_blocks [size_index];
 465         free_blocks [size_index] = info;
 466
 467         sgen_pointer_queue_add (&allocated_blocks, BLOCK_TAG (info));
 468
 469         ++num_major_sections;
 470         return TRUE;
 471 }
 472
 473 static gboolean
 474 obj_is_from_pinned_alloc (char *ptr)
 475 {
 476         MSBlockInfo *block;
 477
 478         FOREACH_BLOCK (block) {
 479                 if (ptr >= MS_BLOCK_FOR_BLOCK_INFO (block) && ptr <= MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE)
 480                         return block->pinned;
 481         } END_FOREACH_BLOCK;
 482         return FALSE;
 483 }
 484
 485 static void*
 486 unlink_slot_from_free_list_uncontested (MSBlockInfo **free_blocks, int size_index)
 487 {
 488         MSBlockInfo *block;
 489         void *obj;
 490
 491         block = free_blocks [size_index];
 492         SGEN_ASSERT (9, block, "no free block to unlink from free_blocks %p size_index %d", free_blocks, size_index);
 493
 494         if (G_UNLIKELY (!block->swept)) {
 495                 stat_major_blocks_lazy_swept ++;
 496                 sweep_block (block, FALSE);
 497         }
 498
 499         obj = block->free_list;
 500         SGEN_ASSERT (9, obj, "block %p in free list had no available object to alloc from", block);
 501
 502         block->free_list = *(void**)obj;
 503         if (!block->free_list) {
 504                 free_blocks [size_index] = block->next_free;
 505                 block->next_free = NULL;
 506         }
 507
 508         return obj;
 509 }
 510
 511 static void*
 512 alloc_obj (MonoVTable *vtable, size_t size, gboolean pinned, gboolean has_references)
 513 {
 514         int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
 515         MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, has_references);
 516         void *obj;
 517
 518         if (!free_blocks [size_index]) {
 519                 if (G_UNLIKELY (!ms_alloc_block (size_index, pinned, has_references)))
 520                         return NULL;
 521         }
 522
 523         obj = unlink_slot_from_free_list_uncontested (free_blocks, size_index);
 524
 525         *(MonoVTable**)obj = vtable;
 526
 527         return obj;
 528 }
 529
 530 static void*
 531 major_alloc_object (MonoVTable *vtable, size_t size, gboolean has_references)
 532 {
 533         return alloc_obj (vtable, size, FALSE, has_references);
 534 }
 535
 536 /*
 537  * We're not freeing the block if it's empty.  We leave that work for
 538  * the next major collection.
 539  *
 540  * This is just called from the domain clearing code, which runs in a
 541  * single thread and has the GC lock, so we don't need an extra lock.
 542  */
 543 static void
 544 free_object (char *obj, size_t size, gboolean pinned)
 545 {
 546         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
 547         int word, bit;
 548
 549         if (!block->swept)
 550                 sweep_block (block, FALSE);
 551         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);
 552         SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p is already free", obj);
 553         MS_CALC_MARK_BIT (word, bit, obj);
 554         SGEN_ASSERT (9, !MS_MARK_BIT (block, word, bit), "object %p has mark bit set");
 555         if (!block->free_list) {
 556                 MSBlockInfo **free_blocks = FREE_BLOCKS (pinned, block->has_references);
 557                 int size_index = MS_BLOCK_OBJ_SIZE_INDEX (size);
 558                 SGEN_ASSERT (9, !block->next_free, "block %p doesn't have a free-list of object but belongs to a free-list of blocks");
 559                 block->next_free = free_blocks [size_index];
 560                 free_blocks [size_index] = block;
 561         }
 562         memset (obj, 0, size);
 563         *(void**)obj = block->free_list;
 564         block->free_list = (void**)obj;
 565 }
 566
 567 static void
 568 major_free_non_pinned_object (char *obj, size_t size)
 569 {
 570         free_object (obj, size, FALSE);
 571 }
 572
 573 /* size is a multiple of SGEN_ALLOC_ALIGN */
 574 static void*
 575 major_alloc_small_pinned_obj (MonoVTable *vtable, size_t size, gboolean has_references)
 576 {
 577         void *res;
 578
 579         res = alloc_obj (vtable, size, TRUE, has_references);
 580          /*If we failed to alloc memory, we better try releasing memory
 581           *as pinned alloc is requested by the runtime.
 582           */
 583          if (!res) {
 584                 sgen_perform_collection (0, GENERATION_OLD, "pinned alloc failure", TRUE);
 585                 res = alloc_obj (vtable, size, TRUE, has_references);
 586          }
 587          return res;
 588 }
 589
 590 static void
 591 free_pinned_object (char *obj, size_t size)
 592 {
 593         free_object (obj, size, TRUE);
 594 }
 595
 596 /*
 597  * size is already rounded up and we hold the GC lock.
 598  */
 599 static void*
 600 major_alloc_degraded (MonoVTable *vtable, size_t size)
 601 {
 602         void *obj;
 603         size_t old_num_sections;
 604
 605         old_num_sections = num_major_sections;
 606
 607         obj = alloc_obj (vtable, size, FALSE, SGEN_VTABLE_HAS_REFERENCES (vtable));
 608         if (G_LIKELY (obj)) {
 609                 HEAVY_STAT (++stat_objects_alloced_degraded);
 610                 HEAVY_STAT (stat_bytes_alloced_degraded += size);
 611                 g_assert (num_major_sections >= old_num_sections);
 612                 sgen_register_major_sections_alloced (num_major_sections - old_num_sections);
 613         }
 614         return obj;
 615 }
 616
 617 #define MAJOR_OBJ_IS_IN_TO_SPACE(obj)   FALSE
 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                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 838                 if (!MS_MARK_BIT ((block), __word, __bit) && MS_OBJ_ALLOCED ((obj), (block))) { \
 839                         MS_SET_MARK_BIT ((block), __word, __bit);       \
 840                         if ((block)->has_references)                    \
 841                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 842                         binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 843                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 844                 }                                                       \
 845         } while (0)
 846 #define MS_MARK_OBJECT_AND_ENQUEUE(obj,desc,block,queue) do {           \
 847                 int __word, __bit;                                      \
 848                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 849                 SGEN_ASSERT (9, MS_OBJ_ALLOCED ((obj), (block)), "object %p not allocated", obj);       \
 850                 if (!MS_MARK_BIT ((block), __word, __bit)) {            \
 851                         MS_SET_MARK_BIT ((block), __word, __bit);       \
 852                         if ((block)->has_references)                    \
 853                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 854                         binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 855                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 856                 }                                                       \
 857         } while (0)
 858 #define MS_PAR_MARK_OBJECT_AND_ENQUEUE(obj,desc,block,queue) do {       \
 859                 int __word, __bit;                                      \
 860                 gboolean __was_marked;                                  \
 861                 SGEN_ASSERT (9, MS_OBJ_ALLOCED ((obj), (block)), "object %p not allocated", obj);       \
 862                 MS_CALC_MARK_BIT (__word, __bit, (obj));                \
 863                 MS_PAR_SET_MARK_BIT (__was_marked, (block), __word, __bit); \
 864                 if (!__was_marked) {                                    \
 865                         if ((block)->has_references)                    \
 866                                 GRAY_OBJECT_ENQUEUE ((queue), (obj), (desc)); \
 867                         binary_protocol_mark ((obj), (gpointer)LOAD_VTABLE ((obj)), sgen_safe_object_get_size ((MonoObject*)(obj))); \
 868                         INC_NUM_MAJOR_OBJECTS_MARKED ();                \
 869                 }                                                       \
 870         } while (0)
 871
 872 static void
 873 pin_major_object (char *obj, SgenGrayQueue *queue)
 874 {
 875         MSBlockInfo *block;
 876
 877 #ifdef SGEN_HAVE_CONCURRENT_MARK
 878         if (concurrent_mark)
 879                 g_assert_not_reached ();
 880 #endif
 881
 882         block = MS_BLOCK_FOR_OBJ (obj);
 883         block->has_pinned = TRUE;
 884         MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 885 }
 886
 887 #include "sgen-major-copy-object.h"
 888
 889 #ifdef SGEN_HAVE_CONCURRENT_MARK
 890 static void
 891 major_copy_or_mark_object_concurrent (void **ptr, void *obj, SgenGrayQueue *queue)
 892 {
 893         g_assert (!SGEN_OBJECT_IS_FORWARDED (obj));
 894
 895         if (!sgen_ptr_in_nursery (obj)) {
 896                 mword objsize;
 897
 898                 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)obj));
 899
 900                 if (objsize <= SGEN_MAX_SMALL_OBJ_SIZE) {
 901                         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
 902                         MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 903                 } else {
 904                         if (sgen_los_object_is_pinned (obj))
 905                                 return;
 906
 907 #ifdef ENABLE_DTRACE
 908                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
 909                                 MonoVTable *vt = (MonoVTable*)SGEN_LOAD_VTABLE (obj);
 910                                 MONO_GC_OBJ_PINNED ((mword)obj, sgen_safe_object_get_size (obj), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
 911                         }
 912 #endif
 913
 914                         sgen_los_pin_object (obj);
 915                         if (SGEN_OBJECT_HAS_REFERENCES (obj))
 916                                 GRAY_OBJECT_ENQUEUE (queue, obj, sgen_obj_get_descriptor (obj));
 917                         INC_NUM_MAJOR_OBJECTS_MARKED ();
 918                 }
 919         }
 920 }
 921 #endif
 922
 923 static void
 924 major_copy_or_mark_object (void **ptr, void *obj, SgenGrayQueue *queue)
 925 {
 926         MSBlockInfo *block;
 927
 928         HEAVY_STAT (++stat_copy_object_called_major);
 929
 930         SGEN_ASSERT (9, obj, "null object from pointer %p", ptr);
 931         SGEN_ASSERT (9, current_collection_generation == GENERATION_OLD, "old gen parallel allocator called from a %d collection", current_collection_generation);
 932
 933         if (sgen_ptr_in_nursery (obj)) {
 934                 int word, bit;
 935                 char *forwarded, *old_obj;
 936
 937                 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 938                         SGEN_UPDATE_REFERENCE (ptr, forwarded);
 939                         return;
 940                 }
 941                 if (SGEN_OBJECT_IS_PINNED (obj))
 942                         return;
 943
 944                 /* An object in the nursery To Space has already been copied and grayed. Nothing to do. */
 945                 if (sgen_nursery_is_to_space (obj))
 946                         return;
 947
 948                 HEAVY_STAT (++stat_objects_copied_major);
 949
 950         do_copy_object:
 951                 old_obj = obj;
 952                 obj = copy_object_no_checks (obj, queue);
 953                 if (G_UNLIKELY (old_obj == obj)) {
 954                         /*If we fail to evacuate an object we just stop doing it for a given block size as all other will surely fail too.*/
 955                         if (!sgen_ptr_in_nursery (obj)) {
 956                                 int size_index;
 957                                 block = MS_BLOCK_FOR_OBJ (obj);
 958                                 size_index = block->obj_size_index;
 959                                 evacuate_block_obj_sizes [size_index] = FALSE;
 960                                 MS_MARK_OBJECT_AND_ENQUEUE (obj, sgen_obj_get_descriptor (obj), block, queue);
 961                         }
 962                         return;
 963                 }
 964                 SGEN_UPDATE_REFERENCE (ptr, obj);
 965
 966                 /*
 967                  * FIXME: See comment for copy_object_no_checks().  If
 968                  * we have that, we can let the allocation function
 969                  * give us the block info, too, and we won't have to
 970                  * re-fetch it.
 971                  *
 972                  * FIXME (2): We should rework this to avoid all those nursery checks.
 973                  */
 974                 /*
 975                  * For the split nursery allocator the object might
 976                  * still be in the nursery despite having being
 977                  * promoted, in which case we can't mark it.
 978                  */
 979                 if (!sgen_ptr_in_nursery (obj)) {
 980                         block = MS_BLOCK_FOR_OBJ (obj);
 981                         MS_CALC_MARK_BIT (word, bit, obj);
 982                         SGEN_ASSERT (9, !MS_MARK_BIT (block, word, bit), "object %p already marked", obj);
 983                         MS_SET_MARK_BIT (block, word, bit);
 984                         binary_protocol_mark (obj, (gpointer)LOAD_VTABLE (obj), sgen_safe_object_get_size ((MonoObject*)obj));
 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                         sgen_los_pin_object (obj);
1035                         if (SGEN_OBJECT_HAS_REFERENCES (obj))
1036                                 GRAY_OBJECT_ENQUEUE (queue, obj, sgen_obj_get_descriptor (obj));
1037                 }
1038         }
1039 }
1040
1041 static void
1042 major_copy_or_mark_object_canonical (void **ptr, SgenGrayQueue *queue)
1043 {
1044         major_copy_or_mark_object (ptr, *ptr, queue);
1045 }
1046
1047 #ifdef SGEN_HAVE_CONCURRENT_MARK
1048 static void
1049 major_copy_or_mark_object_concurrent_canonical (void **ptr, SgenGrayQueue *queue)
1050 {
1051         major_copy_or_mark_object_concurrent (ptr, *ptr, queue);
1052 }
1053 #endif
1054
1055 static long long
1056 major_get_and_reset_num_major_objects_marked (void)
1057 {
1058 #ifdef SGEN_COUNT_NUMBER_OF_MAJOR_OBJECTS_MARKED
1059         long long num = num_major_objects_marked;
1060         num_major_objects_marked = 0;
1061         return num;
1062 #else
1063         return 0;
1064 #endif
1065 }
1066
1067 #include "sgen-major-scan-object.h"
1068
1069 #ifdef SGEN_HAVE_CONCURRENT_MARK
1070 #define SCAN_FOR_CONCURRENT_MARK
1071 #include "sgen-major-scan-object.h"
1072 #undef SCAN_FOR_CONCURRENT_MARK
1073 #endif
1074
1075 static void
1076 mark_pinned_objects_in_block (MSBlockInfo *block, SgenGrayQueue *queue)
1077 {
1078         void **entry, **end;
1079         int last_index = -1;
1080
1081         if (block->pin_queue_first_entry == block->pin_queue_last_entry)
1082                 return;
1083
1084         block->has_pinned = TRUE;
1085
1086         entry = sgen_pinning_get_entry (block->pin_queue_first_entry);
1087         end = sgen_pinning_get_entry (block->pin_queue_last_entry);
1088
1089         for (; entry < end; ++entry) {
1090                 int index = MS_BLOCK_OBJ_INDEX (*entry, block);
1091                 char *obj;
1092                 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);
1093                 if (index == last_index)
1094                         continue;
1095                 obj = MS_BLOCK_OBJ (block, index);
1096                 MS_MARK_OBJECT_AND_ENQUEUE_CHECKED (obj, sgen_obj_get_descriptor (obj), block, queue);
1097                 last_index = index;
1098         }
1099 }
1100
1101 static inline void
1102 sweep_block_for_size (MSBlockInfo *block, int count, int obj_size)
1103 {
1104         int obj_index;
1105
1106         for (obj_index = 0; obj_index < count; ++obj_index) {
1107                 int word, bit;
1108                 void *obj = MS_BLOCK_OBJ_FOR_SIZE (block, obj_index, obj_size);
1109
1110                 MS_CALC_MARK_BIT (word, bit, obj);
1111                 if (MS_MARK_BIT (block, word, bit)) {
1112                         SGEN_ASSERT (9, MS_OBJ_ALLOCED (obj, block), "object %p not allocated", obj);
1113                 } else {
1114                         /* an unmarked object */
1115                         if (MS_OBJ_ALLOCED (obj, block)) {
1116                                 /*
1117                                  * FIXME: Merge consecutive
1118                                  * slots for lower reporting
1119                                  * overhead.  Maybe memset
1120                                  * will also benefit?
1121                                  */
1122                                 binary_protocol_empty (obj, obj_size);
1123                                 MONO_GC_MAJOR_SWEPT ((mword)obj, obj_size);
1124                                 memset (obj, 0, obj_size);
1125                         }
1126                         *(void**)obj = block->free_list;
1127                         block->free_list = obj;
1128                 }
1129         }
1130 }
1131
1132 /*
1133  * sweep_block:
1134  *
1135  *   Traverse BLOCK, freeing and zeroing unused objects.
1136  */
1137 static void
1138 sweep_block (MSBlockInfo *block, gboolean during_major_collection)
1139 {
1140         int count;
1141         void *reversed = NULL;
1142
1143         if (!during_major_collection)
1144                 g_assert (!sgen_concurrent_collection_in_progress ());
1145
1146         if (block->swept)
1147                 return;
1148
1149         count = MS_BLOCK_FREE / block->obj_size;
1150
1151         block->free_list = NULL;
1152
1153         /* Use inline instances specialized to constant sizes, this allows the compiler to replace the memset calls with inline code */
1154         // FIXME: Add more sizes
1155         switch (block->obj_size) {
1156         case 16:
1157                 sweep_block_for_size (block, count, 16);
1158                 break;
1159         default:
1160                 sweep_block_for_size (block, count, block->obj_size);
1161                 break;
1162         }
1163
1164         /* reset mark bits */
1165         memset (block->mark_words, 0, sizeof (mword) * MS_NUM_MARK_WORDS);
1166
1167         /* Reverse free list so that it's in address order */
1168         reversed = NULL;
1169         while (block->free_list) {
1170                 void *next = *(void**)block->free_list;
1171                 *(void**)block->free_list = reversed;
1172                 reversed = block->free_list;
1173                 block->free_list = next;
1174         }
1175         block->free_list = reversed;
1176
1177         block->swept = 1;
1178 }
1179
1180 static inline int
1181 bitcount (mword d)
1182 {
1183         int count = 0;
1184
1185 #ifdef __GNUC__
1186         if (sizeof (mword) == sizeof (unsigned long))
1187                 count += __builtin_popcountl (d);
1188         else
1189                 count += __builtin_popcount (d);
1190 #else
1191         while (d) {
1192                 count ++;
1193                 d &= (d - 1);
1194         }
1195 #endif
1196         return count;
1197 }
1198
1199 static void
1200 ms_sweep (void)
1201 {
1202         int i;
1203         MSBlockInfo *block;
1204
1205         /* statistics for evacuation */
1206         int *slots_available = alloca (sizeof (int) * num_block_obj_sizes);
1207         int *slots_used = alloca (sizeof (int) * num_block_obj_sizes);
1208         int *num_blocks = alloca (sizeof (int) * num_block_obj_sizes);
1209
1210 #ifdef SGEN_HAVE_CONCURRENT_MARK
1211         mword total_evacuate_heap = 0;
1212         mword total_evacuate_saved = 0;
1213 #endif
1214
1215         for (i = 0; i < num_block_obj_sizes; ++i)
1216                 slots_available [i] = slots_used [i] = num_blocks [i] = 0;
1217
1218         /* clear all the free lists */
1219         for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i) {
1220                 MSBlockInfo **free_blocks = free_block_lists [i];
1221                 int j;
1222                 for (j = 0; j < num_block_obj_sizes; ++j)
1223                         free_blocks [j] = NULL;
1224         }
1225
1226         /* traverse all blocks, free and zero unmarked objects */
1227         FOREACH_BLOCK (block) {
1228                 int count;
1229                 gboolean have_live = FALSE;
1230                 gboolean has_pinned;
1231                 gboolean have_free = FALSE;
1232                 int obj_size_index;
1233                 int nused = 0;
1234
1235                 obj_size_index = block->obj_size_index;
1236
1237                 has_pinned = block->has_pinned;
1238                 block->has_pinned = block->pinned;
1239
1240                 block->is_to_space = FALSE;
1241                 block->swept = 0;
1242
1243                 count = MS_BLOCK_FREE / block->obj_size;
1244
1245 #ifdef SGEN_HAVE_CONCURRENT_MARK
1246                 if (block->cardtable_mod_union) {
1247                         sgen_free_internal_dynamic (block->cardtable_mod_union, CARDS_PER_BLOCK, INTERNAL_MEM_CARDTABLE_MOD_UNION);
1248                         block->cardtable_mod_union = NULL;
1249                 }
1250 #endif
1251
1252                 /* Count marked objects in the block */
1253                 for (i = 0; i < MS_NUM_MARK_WORDS; ++i) {
1254                         nused += bitcount (block->mark_words [i]);
1255                 }
1256                 if (nused) {
1257                         have_live = TRUE;
1258                 }
1259                 if (nused < count)
1260                         have_free = TRUE;
1261
1262                 if (!lazy_sweep)
1263                         sweep_block (block, TRUE);
1264
1265                 if (have_live) {
1266                         if (!has_pinned) {
1267                                 ++num_blocks [obj_size_index];
1268                                 slots_used [obj_size_index] += nused;
1269                                 slots_available [obj_size_index] += count;
1270                         }
1271
1272                         /*
1273                          * If there are free slots in the block, add
1274                          * the block to the corresponding free list.
1275                          */
1276                         if (have_free) {
1277                                 MSBlockInfo **free_blocks = FREE_BLOCKS (block->pinned, block->has_references);
1278                                 int index = MS_BLOCK_OBJ_SIZE_INDEX (block->obj_size);
1279                                 block->next_free = free_blocks [index];
1280                                 free_blocks [index] = block;
1281                         }
1282
1283                         update_heap_boundaries_for_block (block);
1284                 } else {
1285                         /*
1286                          * Blocks without live objects are removed from the
1287                          * block list and freed.
1288                          */
1289                         DELETE_BLOCK_IN_FOREACH ();
1290
1291                         binary_protocol_empty (MS_BLOCK_OBJ (block, 0), (char*)MS_BLOCK_OBJ (block, count) - (char*)MS_BLOCK_OBJ (block, 0));
1292                         ms_free_block (block->block);
1293                         sgen_free_internal (block, INTERNAL_MEM_MS_BLOCK_INFO);
1294
1295                         --num_major_sections;
1296                 }
1297         } END_FOREACH_BLOCK;
1298         sgen_pointer_queue_remove_nulls (&allocated_blocks);
1299
1300         for (i = 0; i < num_block_obj_sizes; ++i) {
1301                 float usage = (float)slots_used [i] / (float)slots_available [i];
1302                 if (num_blocks [i] > 5 && usage < evacuation_threshold) {
1303                         evacuate_block_obj_sizes [i] = TRUE;
1304                         /*
1305                         g_print ("slot size %d - %d of %d used\n",
1306                                         block_obj_sizes [i], slots_used [i], slots_available [i]);
1307                         */
1308                 } else {
1309                         evacuate_block_obj_sizes [i] = FALSE;
1310                 }
1311 #ifdef SGEN_HAVE_CONCURRENT_MARK
1312                 {
1313                         mword total_bytes = block_obj_sizes [i] * slots_available [i];
1314                         total_evacuate_heap += total_bytes;
1315                         if (evacuate_block_obj_sizes [i])
1316                                 total_evacuate_saved += total_bytes - block_obj_sizes [i] * slots_used [i];
1317                 }
1318 #endif
1319         }
1320
1321 #ifdef SGEN_HAVE_CONCURRENT_MARK
1322         want_evacuation = (float)total_evacuate_saved / (float)total_evacuate_heap > (1 - concurrent_evacuation_threshold);
1323 #endif
1324
1325         have_swept = TRUE;
1326 }
1327
1328 static void
1329 major_sweep (void)
1330 {
1331         ms_sweep ();
1332 }
1333
1334 static int count_pinned_ref;
1335 static int count_pinned_nonref;
1336 static int count_nonpinned_ref;
1337 static int count_nonpinned_nonref;
1338
1339 static void
1340 count_nonpinned_callback (char *obj, size_t size, void *data)
1341 {
1342         MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
1343
1344         if (vtable->klass->has_references)
1345                 ++count_nonpinned_ref;
1346         else
1347                 ++count_nonpinned_nonref;
1348 }
1349
1350 static void
1351 count_pinned_callback (char *obj, size_t size, void *data)
1352 {
1353         MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
1354
1355         if (vtable->klass->has_references)
1356                 ++count_pinned_ref;
1357         else
1358                 ++count_pinned_nonref;
1359 }
1360
1361 static G_GNUC_UNUSED void
1362 count_ref_nonref_objs (void)
1363 {
1364         int total;
1365
1366         count_pinned_ref = 0;
1367         count_pinned_nonref = 0;
1368         count_nonpinned_ref = 0;
1369         count_nonpinned_nonref = 0;
1370
1371         major_iterate_objects (ITERATE_OBJECTS_SWEEP_NON_PINNED, count_nonpinned_callback, NULL);
1372         major_iterate_objects (ITERATE_OBJECTS_SWEEP_PINNED, count_pinned_callback, NULL);
1373
1374         total = count_pinned_nonref + count_nonpinned_nonref + count_pinned_ref + count_nonpinned_ref;
1375
1376         g_print ("ref: %d pinned %d non-pinned   non-ref: %d pinned %d non-pinned  --  %.1f\n",
1377                         count_pinned_ref, count_nonpinned_ref,
1378                         count_pinned_nonref, count_nonpinned_nonref,
1379                         (count_pinned_nonref + count_nonpinned_nonref) * 100.0 / total);
1380 }
1381
1382 static int
1383 ms_calculate_block_obj_sizes (double factor, int *arr)
1384 {
1385         double target_size = sizeof (MonoObject);
1386         int num_sizes = 0;
1387         int last_size = 0;
1388
1389         do {
1390                 int target_count = (int)ceil (MS_BLOCK_FREE / target_size);
1391                 int size = MIN ((MS_BLOCK_FREE / target_count) & ~(SGEN_ALLOC_ALIGN - 1), SGEN_MAX_SMALL_OBJ_SIZE);
1392
1393                 if (size != last_size) {
1394                         if (arr)
1395                                 arr [num_sizes] = size;
1396                         ++num_sizes;
1397                         last_size = size;
1398                 }
1399
1400                 target_size *= factor;
1401         } while (last_size < SGEN_MAX_SMALL_OBJ_SIZE);
1402
1403         return num_sizes;
1404 }
1405
1406 /* only valid during minor collections */
1407 static mword old_num_major_sections;
1408
1409 static void
1410 major_start_nursery_collection (void)
1411 {
1412 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1413         consistency_check ();
1414 #endif
1415
1416         old_num_major_sections = num_major_sections;
1417 }
1418
1419 static void
1420 major_finish_nursery_collection (void)
1421 {
1422 #ifdef MARKSWEEP_CONSISTENCY_CHECK
1423         consistency_check ();
1424 #endif
1425         sgen_register_major_sections_alloced (num_major_sections - old_num_major_sections);
1426 }
1427
1428 static void
1429 major_start_major_collection (void)
1430 {
1431         int i;
1432
1433         /* clear the free lists */
1434         for (i = 0; i < num_block_obj_sizes; ++i) {
1435                 if (!evacuate_block_obj_sizes [i])
1436                         continue;
1437
1438                 free_block_lists [0][i] = NULL;
1439                 free_block_lists [MS_BLOCK_FLAG_REFS][i] = NULL;
1440         }
1441
1442         // Sweep all unswept blocks
1443         if (lazy_sweep) {
1444                 MSBlockInfo *block;
1445
1446                 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, TRUE);
1447
1448                 FOREACH_BLOCK (block) {
1449                         sweep_block (block, TRUE);
1450                 } END_FOREACH_BLOCK;
1451
1452                 MONO_GC_SWEEP_END (GENERATION_OLD, TRUE);
1453         }
1454 }
1455
1456 static void
1457 major_finish_major_collection (void)
1458 {
1459 }
1460
1461 #if SIZEOF_VOID_P != 8
1462 static int
1463 compare_pointers (const void *va, const void *vb) {
1464         char *a = *(char**)va, *b = *(char**)vb;
1465         if (a < b)
1466                 return -1;
1467         if (a > b)
1468                 return 1;
1469         return 0;
1470 }
1471 #endif
1472
1473 static void
1474 major_have_computer_minor_collection_allowance (void)
1475 {
1476         size_t section_reserve = sgen_get_minor_collection_allowance () / MS_BLOCK_SIZE;
1477
1478         g_assert (have_swept);
1479
1480 #if SIZEOF_VOID_P != 8
1481         {
1482                 int i, num_empty_blocks_orig, num_blocks, arr_length;
1483                 void *block;
1484                 void **empty_block_arr;
1485                 void **rebuild_next;
1486
1487 #ifdef TARGET_WIN32
1488                 /*
1489                  * sgen_free_os_memory () asserts in mono_vfree () because windows doesn't like freeing the middle of
1490                  * a VirtualAlloc ()-ed block.
1491                  */
1492                 return;
1493 #endif
1494
1495                 if (num_empty_blocks <= section_reserve)
1496                         return;
1497                 SGEN_ASSERT (0, num_empty_blocks > 0, "section reserve can't be negative");
1498
1499                 num_empty_blocks_orig = num_empty_blocks;
1500                 empty_block_arr = (void**)sgen_alloc_internal_dynamic (sizeof (void*) * num_empty_blocks_orig,
1501                                 INTERNAL_MEM_MS_BLOCK_INFO_SORT, FALSE);
1502                 if (!empty_block_arr)
1503                         goto fallback;
1504
1505                 i = 0;
1506                 for (block = empty_blocks; block; block = *(void**)block)
1507                         empty_block_arr [i++] = block;
1508                 SGEN_ASSERT (0, i == num_empty_blocks, "empty block count wrong");
1509
1510                 sgen_qsort (empty_block_arr, num_empty_blocks, sizeof (void*), compare_pointers);
1511
1512                 /*
1513                  * We iterate over the free blocks, trying to find MS_BLOCK_ALLOC_NUM
1514                  * contiguous ones.  If we do, we free them.  If that's not enough to get to
1515                  * section_reserve, we halve the number of contiguous blocks we're looking
1516                  * for and have another go, until we're done with looking for pairs of
1517                  * blocks, at which point we give up and go to the fallback.
1518                  */
1519                 arr_length = num_empty_blocks_orig;
1520                 num_blocks = MS_BLOCK_ALLOC_NUM;
1521                 while (num_empty_blocks > section_reserve && num_blocks > 1) {
1522                         int first = -1;
1523                         int dest = 0;
1524
1525                         dest = 0;
1526                         for (i = 0; i < arr_length; ++i) {
1527                                 int d = dest;
1528                                 void *block = empty_block_arr [i];
1529                                 SGEN_ASSERT (0, block, "we're not shifting correctly");
1530                                 if (i != dest) {
1531                                         empty_block_arr [dest] = block;
1532                                         /*
1533                                          * This is not strictly necessary, but we're
1534                                          * cautious.
1535                                          */
1536                                         empty_block_arr [i] = NULL;
1537                                 }
1538                                 ++dest;
1539
1540                                 if (first < 0) {
1541                                         first = d;
1542                                         continue;
1543                                 }
1544
1545                                 SGEN_ASSERT (0, first >= 0 && d > first, "algorithm is wrong");
1546
1547                                 if ((char*)block != ((char*)empty_block_arr [d-1]) + MS_BLOCK_SIZE) {
1548                                         first = d;
1549                                         continue;
1550                                 }
1551
1552                                 if (d + 1 - first == num_blocks) {
1553                                         /*
1554                                          * We found num_blocks contiguous blocks.  Free them
1555                                          * and null their array entries.  As an optimization
1556                                          * we could, instead of nulling the entries, shift
1557                                          * the following entries over to the left, while
1558                                          * we're iterating.
1559                                          */
1560                                         int j;
1561                                         sgen_free_os_memory (empty_block_arr [first], MS_BLOCK_SIZE * num_blocks, SGEN_ALLOC_HEAP);
1562                                         for (j = first; j <= d; ++j)
1563                                                 empty_block_arr [j] = NULL;
1564                                         dest = first;
1565                                         first = -1;
1566
1567                                         num_empty_blocks -= num_blocks;
1568
1569                                         stat_major_blocks_freed += num_blocks;
1570                                         if (num_blocks == MS_BLOCK_ALLOC_NUM)
1571                                                 stat_major_blocks_freed_ideal += num_blocks;
1572                                         else
1573                                                 stat_major_blocks_freed_less_ideal += num_blocks;
1574
1575                                 }
1576                         }
1577
1578                         SGEN_ASSERT (0, dest <= i && dest <= arr_length, "array length is off");
1579                         arr_length = dest;
1580                         SGEN_ASSERT (0, arr_length == num_empty_blocks, "array length is off");
1581
1582                         num_blocks >>= 1;
1583                 }
1584
1585                 /* rebuild empty_blocks free list */
1586                 rebuild_next = (void**)&empty_blocks;
1587                 for (i = 0; i < arr_length; ++i) {
1588                         void *block = empty_block_arr [i];
1589                         SGEN_ASSERT (0, block, "we're missing blocks");
1590                         *rebuild_next = block;
1591                         rebuild_next = (void**)block;
1592                 }
1593                 *rebuild_next = NULL;
1594
1595                 /* free array */
1596                 sgen_free_internal_dynamic (empty_block_arr, sizeof (void*) * num_empty_blocks_orig, INTERNAL_MEM_MS_BLOCK_INFO_SORT);
1597         }
1598
1599         SGEN_ASSERT (0, num_empty_blocks >= 0, "we freed more blocks than we had in the first place?");
1600
1601  fallback:
1602         /*
1603          * This is our threshold.  If there's not more empty than used blocks, we won't
1604          * release uncontiguous blocks, in fear of fragmenting the address space.
1605          */
1606         if (num_empty_blocks <= num_major_sections)
1607                 return;
1608 #endif
1609
1610         while (num_empty_blocks > section_reserve) {
1611                 void *next = *(void**)empty_blocks;
1612                 sgen_free_os_memory (empty_blocks, MS_BLOCK_SIZE, SGEN_ALLOC_HEAP);
1613                 empty_blocks = next;
1614                 /*
1615                  * Needs not be atomic because this is running
1616                  * single-threaded.
1617                  */
1618                 --num_empty_blocks;
1619
1620                 ++stat_major_blocks_freed;
1621 #if SIZEOF_VOID_P != 8
1622                 ++stat_major_blocks_freed_individual;
1623 #endif
1624         }
1625 }
1626
1627 static void
1628 major_find_pin_queue_start_ends (SgenGrayQueue *queue)
1629 {
1630         MSBlockInfo *block;
1631
1632         FOREACH_BLOCK (block) {
1633                 sgen_find_optimized_pin_queue_area (MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SKIP, MS_BLOCK_FOR_BLOCK_INFO (block) + MS_BLOCK_SIZE,
1634                                 &block->pin_queue_first_entry, &block->pin_queue_last_entry);
1635         } END_FOREACH_BLOCK;
1636 }
1637
1638 static void
1639 major_pin_objects (SgenGrayQueue *queue)
1640 {
1641         MSBlockInfo *block;
1642
1643         FOREACH_BLOCK (block) {
1644                 mark_pinned_objects_in_block (block, queue);
1645         } END_FOREACH_BLOCK;
1646 }
1647
1648 static void
1649 major_init_to_space (void)
1650 {
1651 }
1652
1653 static void
1654 major_report_pinned_memory_usage (void)
1655 {
1656         g_assert_not_reached ();
1657 }
1658
1659 static gint64
1660 major_get_used_size (void)
1661 {
1662         gint64 size = 0;
1663         MSBlockInfo *block;
1664
1665         FOREACH_BLOCK (block) {
1666                 int count = MS_BLOCK_FREE / block->obj_size;
1667                 void **iter;
1668                 size += count * block->obj_size;
1669                 for (iter = block->free_list; iter; iter = (void**)*iter)
1670                         size -= block->obj_size;
1671         } END_FOREACH_BLOCK;
1672
1673         return size;
1674 }
1675
1676 static size_t
1677 get_num_major_sections (void)
1678 {
1679         return num_major_sections;
1680 }
1681
1682 static gboolean
1683 major_handle_gc_param (const char *opt)
1684 {
1685         if (g_str_has_prefix (opt, "evacuation-threshold=")) {
1686                 const char *arg = strchr (opt, '=') + 1;
1687                 int percentage = atoi (arg);
1688                 if (percentage < 0 || percentage > 100) {
1689                         fprintf (stderr, "evacuation-threshold must be an integer in the range 0-100.\n");
1690                         exit (1);
1691                 }
1692                 evacuation_threshold = (float)percentage / 100.0f;
1693                 return TRUE;
1694         } else if (!strcmp (opt, "lazy-sweep")) {
1695                 lazy_sweep = TRUE;
1696                 return TRUE;
1697         } else if (!strcmp (opt, "no-lazy-sweep")) {
1698                 lazy_sweep = FALSE;
1699                 return TRUE;
1700         }
1701
1702         return FALSE;
1703 }
1704
1705 static void
1706 major_print_gc_param_usage (void)
1707 {
1708         fprintf (stderr,
1709                         ""
1710                         "  evacuation-threshold=P (where P is a percentage, an integer in 0-100)\n"
1711                         "  (no-)lazy-sweep\n"
1712                         );
1713 }
1714
1715 static void
1716 major_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
1717 {
1718         MSBlockInfo *block;
1719         gboolean has_references;
1720
1721         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1722                 if (has_references)
1723                         callback ((mword)MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE);
1724         } END_FOREACH_BLOCK;
1725 }
1726
1727 #ifdef HEAVY_STATISTICS
1728 extern long long marked_cards;
1729 extern long long scanned_cards;
1730 extern long long scanned_objects;
1731 extern long long remarked_cards;
1732 #endif
1733
1734 #define CARD_WORDS_PER_BLOCK (CARDS_PER_BLOCK / SIZEOF_VOID_P)
1735 /*
1736  * MS blocks are 16K aligned.
1737  * Cardtables are 4K aligned, at least.
1738  * This means that the cardtable of a given block is 32 bytes aligned.
1739  */
1740 static guint8*
1741 initial_skip_card (guint8 *card_data)
1742 {
1743         mword *cards = (mword*)card_data;
1744         mword card;
1745         int i;
1746         for (i = 0; i < CARD_WORDS_PER_BLOCK; ++i) {
1747                 card = cards [i];
1748                 if (card)
1749                         break;
1750         }
1751
1752         if (i == CARD_WORDS_PER_BLOCK)
1753                 return card_data + CARDS_PER_BLOCK;
1754
1755 #if defined(__i386__) && defined(__GNUC__)
1756         return card_data + i * 4 +  (__builtin_ffs (card) - 1) / 8;
1757 #elif defined(__x86_64__) && defined(__GNUC__)
1758         return card_data + i * 8 +  (__builtin_ffsll (card) - 1) / 8;
1759 #elif defined(__s390x__) && defined(__GNUC__)
1760         return card_data + i * 8 +  (__builtin_ffsll (GUINT64_TO_LE(card)) - 1) / 8;
1761 #else
1762         for (i = i * SIZEOF_VOID_P; i < CARDS_PER_BLOCK; ++i) {
1763                 if (card_data [i])
1764                         return &card_data [i];
1765         }
1766         return card_data;
1767 #endif
1768 }
1769
1770
1771 static G_GNUC_UNUSED guint8*
1772 skip_card (guint8 *card_data, guint8 *card_data_end)
1773 {
1774         while (card_data < card_data_end && !*card_data)
1775                 ++card_data;
1776         return card_data;
1777 }
1778
1779 #define MS_BLOCK_OBJ_INDEX_FAST(o,b,os) (((char*)(o) - ((b) + MS_BLOCK_SKIP)) / (os))
1780 #define MS_BLOCK_OBJ_FAST(b,os,i)                       ((b) + MS_BLOCK_SKIP + (os) * (i))
1781 #define MS_OBJ_ALLOCED_FAST(o,b)                (*(void**)(o) && (*(char**)(o) < (b) || *(char**)(o) >= (b) + MS_BLOCK_SIZE))
1782
1783 static void
1784 major_scan_card_table (gboolean mod_union, SgenGrayQueue *queue)
1785 {
1786         MSBlockInfo *block;
1787         gboolean has_references;
1788         ScanObjectFunc scan_func = sgen_get_current_object_ops ()->scan_object;
1789
1790 #ifdef SGEN_HAVE_CONCURRENT_MARK
1791         if (!concurrent_mark)
1792                 g_assert (!mod_union);
1793 #else
1794         g_assert (!mod_union);
1795 #endif
1796
1797         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1798                 int block_obj_size;
1799                 char *block_start;
1800
1801                 if (!has_references)
1802                         continue;
1803
1804                 block_obj_size = block->obj_size;
1805                 block_start = MS_BLOCK_FOR_BLOCK_INFO (block);
1806
1807                 if (block_obj_size >= CARD_SIZE_IN_BYTES) {
1808                         guint8 *cards;
1809 #ifndef SGEN_HAVE_OVERLAPPING_CARDS
1810                         guint8 cards_data [CARDS_PER_BLOCK];
1811 #endif
1812                         char *obj, *end, *base;
1813
1814                         if (mod_union) {
1815 #ifdef SGEN_HAVE_CONCURRENT_MARK
1816                                 cards = block->cardtable_mod_union;
1817                                 /*
1818                                  * This happens when the nursery
1819                                  * collection that precedes finishing
1820                                  * the concurrent collection allocates
1821                                  * new major blocks.
1822                                  */
1823                                 if (!cards)
1824                                         continue;
1825 #endif
1826                         } else {
1827                         /*We can avoid the extra copy since the remark cardtable was cleaned before */
1828 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
1829                                 cards = sgen_card_table_get_card_scan_address ((mword)block_start);
1830 #else
1831                                 cards = cards_data;
1832                                 if (!sgen_card_table_get_card_data (cards_data, (mword)block_start, CARDS_PER_BLOCK))
1833                                         continue;
1834 #endif
1835                         }
1836
1837                         obj = (char*)MS_BLOCK_OBJ_FAST (block_start, block_obj_size, 0);
1838                         end = block_start + MS_BLOCK_SIZE;
1839                         base = sgen_card_table_align_pointer (obj);
1840
1841                         while (obj < end) {
1842                                 size_t card_offset;
1843
1844                                 if (!block->swept)
1845                                         sweep_block (block, FALSE);
1846
1847                                 if (!MS_OBJ_ALLOCED_FAST (obj, block_start))
1848                                         goto next_large;
1849
1850                                 if (mod_union) {
1851                                         /* FIXME: do this more efficiently */
1852                                         int w, b;
1853                                         MS_CALC_MARK_BIT (w, b, obj);
1854                                         if (!MS_MARK_BIT (block, w, b))
1855                                                 goto next_large;
1856                                 }
1857
1858                                 card_offset = (obj - base) >> CARD_BITS;
1859                                 sgen_cardtable_scan_object (obj, block_obj_size, cards + card_offset, mod_union, queue);
1860
1861                         next_large:
1862                                 obj += block_obj_size;
1863                         }
1864                 } else {
1865                         guint8 *card_data, *card_base;
1866                         guint8 *card_data_end;
1867
1868                         /*
1869                          * This is safe in face of card aliasing for the following reason:
1870                          *
1871                          * Major blocks are 16k aligned, or 32 cards aligned.
1872                          * Cards aliasing happens in powers of two, so as long as major blocks are aligned to their
1873                          * sizes, they won't overflow the cardtable overlap modulus.
1874                          */
1875                         if (mod_union) {
1876 #ifdef SGEN_HAVE_CONCURRENT_MARK
1877                                 card_data = card_base = block->cardtable_mod_union;
1878                                 /*
1879                                  * This happens when the nursery
1880                                  * collection that precedes finishing
1881                                  * the concurrent collection allocates
1882                                  * new major blocks.
1883                                  */
1884                                 if (!card_data)
1885                                         continue;
1886 #else
1887                                 g_assert_not_reached ();
1888                                 card_data = NULL;
1889 #endif
1890                         } else {
1891                                 card_data = card_base = sgen_card_table_get_card_scan_address ((mword)block_start);
1892                         }
1893                         card_data_end = card_data + CARDS_PER_BLOCK;
1894
1895                         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)) {
1896                                 size_t index;
1897                                 size_t idx = card_data - card_base;
1898                                 char *start = (char*)(block_start + idx * CARD_SIZE_IN_BYTES);
1899                                 char *end = start + CARD_SIZE_IN_BYTES;
1900                                 char *first_obj, *obj;
1901
1902                                 HEAVY_STAT (++scanned_cards);
1903
1904                                 if (!*card_data)
1905                                         continue;
1906
1907                                 if (!block->swept)
1908                                         sweep_block (block, FALSE);
1909
1910                                 HEAVY_STAT (++marked_cards);
1911
1912                                 sgen_card_table_prepare_card_for_scanning (card_data);
1913
1914                                 if (idx == 0)
1915                                         index = 0;
1916                                 else
1917                                         index = MS_BLOCK_OBJ_INDEX_FAST (start, block_start, block_obj_size);
1918
1919                                 obj = first_obj = (char*)MS_BLOCK_OBJ_FAST (block_start, block_obj_size, index);
1920                                 while (obj < end) {
1921                                         if (!MS_OBJ_ALLOCED_FAST (obj, block_start))
1922                                                 goto next_small;
1923
1924                                         if (mod_union) {
1925                                                 /* FIXME: do this more efficiently */
1926                                                 int w, b;
1927                                                 MS_CALC_MARK_BIT (w, b, obj);
1928                                                 if (!MS_MARK_BIT (block, w, b))
1929                                                         goto next_small;
1930                                         }
1931
1932                                         HEAVY_STAT (++scanned_objects);
1933                                         scan_func (obj, sgen_obj_get_descriptor (obj), queue);
1934                                 next_small:
1935                                         obj += block_obj_size;
1936                                 }
1937                                 HEAVY_STAT (if (*card_data) ++remarked_cards);
1938                                 binary_protocol_card_scan (first_obj, obj - first_obj);
1939                         }
1940                 }
1941         } END_FOREACH_BLOCK;
1942 }
1943
1944 static void
1945 major_count_cards (long long *num_total_cards, long long *num_marked_cards)
1946 {
1947         MSBlockInfo *block;
1948         gboolean has_references;
1949         long long total_cards = 0;
1950         long long marked_cards = 0;
1951
1952         FOREACH_BLOCK_HAS_REFERENCES (block, has_references) {
1953                 guint8 *cards = sgen_card_table_get_card_scan_address ((mword) MS_BLOCK_FOR_BLOCK_INFO (block));
1954                 int i;
1955
1956                 if (!has_references)
1957                         continue;
1958
1959                 total_cards += CARDS_PER_BLOCK;
1960                 for (i = 0; i < CARDS_PER_BLOCK; ++i) {
1961                         if (cards [i])
1962                                 ++marked_cards;
1963                 }
1964         } END_FOREACH_BLOCK;
1965
1966         *num_total_cards = total_cards;
1967         *num_marked_cards = marked_cards;
1968 }
1969
1970 #ifdef SGEN_HAVE_CONCURRENT_MARK
1971 static void
1972 update_cardtable_mod_union (void)
1973 {
1974         MSBlockInfo *block;
1975
1976         FOREACH_BLOCK (block) {
1977                 size_t num_cards;
1978
1979                 block->cardtable_mod_union = sgen_card_table_update_mod_union (block->cardtable_mod_union,
1980                                 MS_BLOCK_FOR_BLOCK_INFO (block), MS_BLOCK_SIZE, &num_cards);
1981
1982                 SGEN_ASSERT (0, num_cards == CARDS_PER_BLOCK, "Number of cards calculation is wrong");
1983         } END_FOREACH_BLOCK;
1984 }
1985
1986 static guint8*
1987 major_get_cardtable_mod_union_for_object (char *obj)
1988 {
1989         MSBlockInfo *block = MS_BLOCK_FOR_OBJ (obj);
1990         return &block->cardtable_mod_union [(obj - (char*)sgen_card_table_align_pointer (MS_BLOCK_FOR_BLOCK_INFO (block))) >> CARD_BITS];
1991 }
1992 #endif
1993
1994 static void
1995 alloc_free_block_lists (MSBlockInfo ***lists)
1996 {
1997         int i;
1998         for (i = 0; i < MS_BLOCK_TYPE_MAX; ++i)
1999                 lists [i] = sgen_alloc_internal_dynamic (sizeof (MSBlockInfo*) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2000 }
2001
2002 #undef pthread_create
2003
2004 static void
2005 post_param_init (SgenMajorCollector *collector)
2006 {
2007         collector->sweeps_lazily = lazy_sweep;
2008 }
2009
2010 #ifdef SGEN_HAVE_CONCURRENT_MARK
2011 static void
2012 sgen_marksweep_init_internal (SgenMajorCollector *collector, gboolean is_concurrent)
2013 #else // SGEN_HAVE_CONCURRENT_MARK
2014 #error unknown configuration
2015 #endif // SGEN_HAVE_CONCURRENT_MARK
2016 {
2017         int i;
2018
2019         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_MS_BLOCK_INFO, sizeof (MSBlockInfo));
2020
2021         num_block_obj_sizes = ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, NULL);
2022         block_obj_sizes = sgen_alloc_internal_dynamic (sizeof (int) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2023         ms_calculate_block_obj_sizes (MS_BLOCK_OBJ_SIZE_FACTOR, block_obj_sizes);
2024
2025         evacuate_block_obj_sizes = sgen_alloc_internal_dynamic (sizeof (gboolean) * num_block_obj_sizes, INTERNAL_MEM_MS_TABLES, TRUE);
2026         for (i = 0; i < num_block_obj_sizes; ++i)
2027                 evacuate_block_obj_sizes [i] = FALSE;
2028
2029         /*
2030         {
2031                 int i;
2032                 g_print ("block object sizes:\n");
2033                 for (i = 0; i < num_block_obj_sizes; ++i)
2034                         g_print ("%d\n", block_obj_sizes [i]);
2035         }
2036         */
2037
2038         alloc_free_block_lists (free_block_lists);
2039
2040         for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES; ++i)
2041                 fast_block_obj_size_indexes [i] = ms_find_block_obj_size_index (i * 8);
2042         for (i = 0; i < MS_NUM_FAST_BLOCK_OBJ_SIZE_INDEXES * 8; ++i)
2043                 g_assert (MS_BLOCK_OBJ_SIZE_INDEX (i) == ms_find_block_obj_size_index (i));
2044
2045         mono_counters_register ("# major blocks allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_alloced);
2046         mono_counters_register ("# major blocks freed", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed);
2047         mono_counters_register ("# major blocks lazy swept", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_lazy_swept);
2048         mono_counters_register ("# major objects evacuated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_objects_evacuated);
2049 #if SIZEOF_VOID_P != 8
2050         mono_counters_register ("# major blocks freed ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_ideal);
2051         mono_counters_register ("# major blocks freed less ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_less_ideal);
2052         mono_counters_register ("# major blocks freed individually", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_freed_individual);
2053         mono_counters_register ("# major blocks allocated less ideally", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_major_blocks_alloced_less_ideal);
2054 #endif
2055
2056         collector->section_size = MAJOR_SECTION_SIZE;
2057
2058 #ifdef SGEN_HAVE_CONCURRENT_MARK
2059         concurrent_mark = is_concurrent;
2060         if (is_concurrent) {
2061                 collector->is_concurrent = TRUE;
2062                 collector->want_synchronous_collection = &want_evacuation;
2063         } else
2064 #endif
2065         {
2066                 collector->is_concurrent = FALSE;
2067                 collector->want_synchronous_collection = NULL;
2068         }
2069         collector->get_and_reset_num_major_objects_marked = major_get_and_reset_num_major_objects_marked;
2070         collector->supports_cardtable = TRUE;
2071
2072         collector->have_swept = &have_swept;
2073
2074         collector->alloc_heap = major_alloc_heap;
2075         collector->is_object_live = major_is_object_live;
2076         collector->alloc_small_pinned_obj = major_alloc_small_pinned_obj;
2077         collector->alloc_degraded = major_alloc_degraded;
2078
2079         collector->alloc_object = major_alloc_object;
2080         collector->free_pinned_object = free_pinned_object;
2081         collector->iterate_objects = major_iterate_objects;
2082         collector->free_non_pinned_object = major_free_non_pinned_object;
2083         collector->find_pin_queue_start_ends = major_find_pin_queue_start_ends;
2084         collector->pin_objects = major_pin_objects;
2085         collector->pin_major_object = pin_major_object;
2086         collector->scan_card_table = major_scan_card_table;
2087         collector->iterate_live_block_ranges = (void*)(void*) major_iterate_live_block_ranges;
2088 #ifdef SGEN_HAVE_CONCURRENT_MARK
2089         if (is_concurrent) {
2090                 collector->update_cardtable_mod_union = update_cardtable_mod_union;
2091                 collector->get_cardtable_mod_union_for_object = major_get_cardtable_mod_union_for_object;
2092         }
2093 #endif
2094         collector->init_to_space = major_init_to_space;
2095         collector->sweep = major_sweep;
2096         collector->check_scan_starts = major_check_scan_starts;
2097         collector->dump_heap = major_dump_heap;
2098         collector->get_used_size = major_get_used_size;
2099         collector->start_nursery_collection = major_start_nursery_collection;
2100         collector->finish_nursery_collection = major_finish_nursery_collection;
2101         collector->start_major_collection = major_start_major_collection;
2102         collector->finish_major_collection = major_finish_major_collection;
2103         collector->have_computed_minor_collection_allowance = major_have_computer_minor_collection_allowance;
2104         collector->ptr_is_in_non_pinned_space = major_ptr_is_in_non_pinned_space;
2105         collector->obj_is_from_pinned_alloc = obj_is_from_pinned_alloc;
2106         collector->report_pinned_memory_usage = major_report_pinned_memory_usage;
2107         collector->get_num_major_sections = get_num_major_sections;
2108         collector->handle_gc_param = major_handle_gc_param;
2109         collector->print_gc_param_usage = major_print_gc_param_usage;
2110         collector->post_param_init = post_param_init;
2111         collector->is_valid_object = major_is_valid_object;
2112         collector->describe_pointer = major_describe_pointer;
2113         collector->count_cards = major_count_cards;
2114
2115         collector->major_ops.copy_or_mark_object = major_copy_or_mark_object_canonical;
2116         collector->major_ops.scan_object = major_scan_object;
2117 #ifdef SGEN_HAVE_CONCURRENT_MARK
2118         if (is_concurrent) {
2119                 collector->major_concurrent_ops.copy_or_mark_object = major_copy_or_mark_object_concurrent_canonical;
2120                 collector->major_concurrent_ops.scan_object = major_scan_object_concurrent;
2121                 collector->major_concurrent_ops.scan_vtype = major_scan_vtype_concurrent;
2122         }
2123 #endif
2124
2125         /*cardtable requires major pages to be 8 cards aligned*/
2126         g_assert ((MS_BLOCK_SIZE % (8 * CARD_SIZE_IN_BYTES)) == 0);
2127 }
2128
2129 #ifdef SGEN_HAVE_CONCURRENT_MARK
2130 void
2131 sgen_marksweep_init (SgenMajorCollector *collector)
2132 {
2133         sgen_marksweep_init_internal (collector, FALSE);
2134 }
2135
2136 void
2137 sgen_marksweep_conc_init (SgenMajorCollector *collector)
2138 {
2139         sgen_marksweep_init_internal (collector, TRUE);
2140 }
2141 #endif
2142
2143 #endif