mono/sgen/sgen-los.c

   1 /*
   2  * sgen-los.c: Large objects space.
   3  *
   4  * Author:
   5  *      Paolo Molaro (lupus@ximian.com)
   6  *
   7  * Copyright 2005-2010 Novell, Inc (http://www.novell.com)
   8  *
   9  * Thread start/stop adapted from Boehm's GC:
  10  * Copyright (c) 1994 by Xerox Corporation.  All rights reserved.
  11  * Copyright (c) 1996 by Silicon Graphics.  All rights reserved.
  12  * Copyright (c) 1998 by Fergus Henderson.  All rights reserved.
  13  * Copyright (c) 2000-2004 by Hewlett-Packard Company.  All rights reserved.
  14  * Copyright 2001-2003 Ximian, Inc
  15  * Copyright 2003-2010 Novell, Inc.
  16  * Copyright (C) 2012 Xamarin Inc
  17  *
  18  * This library is free software; you can redistribute it and/or
  19  * modify it under the terms of the GNU Library General Public
  20  * License 2.0 as published by the Free Software Foundation;
  21  *
  22  * This library is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25  * Library General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU Library General Public
  28  * License 2.0 along with this library; if not, write to the Free
  29  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  30  */
  31
  32 #include "config.h"
  33
  34 #ifdef HAVE_SGEN_GC
  35
  36 #include <string.h>
  37
  38 #include "mono/sgen/sgen-gc.h"
  39 #include "mono/sgen/sgen-protocol.h"
  40 #include "mono/sgen/sgen-cardtable.h"
  41 #include "mono/sgen/sgen-memory-governor.h"
  42 #include "mono/sgen/sgen-client.h"
  43
  44 #define LOS_SECTION_SIZE        (1024 * 1024)
  45
  46 /*
  47  * This shouldn't be much smaller or larger than MAX_SMALL_OBJ_SIZE.
  48  * Must be at least sizeof (LOSSection).
  49  */
  50 #define LOS_CHUNK_SIZE          4096
  51 #define LOS_CHUNK_BITS          12
  52
  53 /* Largest object that can be allocated in a section. */
  54 #define LOS_SECTION_OBJECT_LIMIT        (LOS_SECTION_SIZE - LOS_CHUNK_SIZE - sizeof (LOSObject))
  55 //#define LOS_SECTION_OBJECT_LIMIT      0
  56 #define LOS_SECTION_NUM_CHUNKS          ((LOS_SECTION_SIZE >> LOS_CHUNK_BITS) - 1)
  57
  58 #define LOS_SECTION_FOR_OBJ(obj)        ((LOSSection*)((mword)(obj) & ~(mword)(LOS_SECTION_SIZE - 1)))
  59 #define LOS_CHUNK_INDEX(obj,section)    (((char*)(obj) - (char*)(section)) >> LOS_CHUNK_BITS)
  60
  61 #define LOS_NUM_FAST_SIZES              32
  62
  63 typedef struct _LOSFreeChunks LOSFreeChunks;
  64 struct _LOSFreeChunks {
  65         LOSFreeChunks *next_size;
  66         size_t size;
  67 };
  68
  69 typedef struct _LOSSection LOSSection;
  70 struct _LOSSection {
  71         LOSSection *next;
  72         size_t num_free_chunks;
  73         unsigned char *free_chunk_map;
  74 };
  75
  76 LOSObject *los_object_list = NULL;
  77 mword los_memory_usage = 0;
  78
  79 static LOSSection *los_sections = NULL;
  80 static LOSFreeChunks *los_fast_free_lists [LOS_NUM_FAST_SIZES]; /* 0 is for larger sizes */
  81 static mword los_num_objects = 0;
  82 static int los_num_sections = 0;
  83
  84 //#define USE_MALLOC
  85 //#define LOS_CONSISTENCY_CHECK
  86 //#define LOS_DUMMY
  87
  88 #ifdef LOS_DUMMY
  89 #define LOS_SEGMENT_SIZE        (4096 * 1024)
  90
  91 static char *los_segment = NULL;
  92 static int los_segment_index = 0;
  93 #endif
  94
  95 mword
  96 sgen_los_object_size (LOSObject *obj)
  97 {
  98         return obj->size & ~1L;
  99 }
 100
 101 #ifdef LOS_CONSISTENCY_CHECK
 102 static void
 103 los_consistency_check (void)
 104 {
 105         LOSSection *section;
 106         LOSObject *obj;
 107         int i;
 108         mword memory_usage = 0;
 109
 110         for (obj = los_object_list; obj; obj = obj->next) {
 111                 mword obj_size = sgen_los_object_size (obj);
 112                 char *end = obj->data + obj_size;
 113                 int start_index, num_chunks;
 114
 115                 memory_usage += obj_size;
 116
 117                 if (obj_size > LOS_SECTION_OBJECT_LIMIT)
 118                         continue;
 119
 120                 section = LOS_SECTION_FOR_OBJ (obj);
 121
 122                 g_assert (end <= (char*)section + LOS_SECTION_SIZE);
 123
 124                 start_index = LOS_CHUNK_INDEX (obj, section);
 125                 num_chunks = (obj_size + sizeof (LOSObject) + LOS_CHUNK_SIZE - 1) >> LOS_CHUNK_BITS;
 126                 for (i = start_index; i < start_index + num_chunks; ++i)
 127                         g_assert (!section->free_chunk_map [i]);
 128         }
 129
 130         for (i = 0; i < LOS_NUM_FAST_SIZES; ++i) {
 131                 LOSFreeChunks *size_chunks;
 132                 for (size_chunks = los_fast_free_lists [i]; size_chunks; size_chunks = size_chunks->next_size) {
 133                         LOSSection *section = LOS_SECTION_FOR_OBJ (size_chunks);
 134                         int j, num_chunks, start_index;
 135
 136                         if (i == 0)
 137                                 g_assert (size_chunks->size >= LOS_NUM_FAST_SIZES * LOS_CHUNK_SIZE);
 138                         else
 139                                 g_assert (size_chunks->size == i * LOS_CHUNK_SIZE);
 140
 141                         num_chunks = size_chunks->size >> LOS_CHUNK_BITS;
 142                         start_index = LOS_CHUNK_INDEX (size_chunks, section);
 143                         for (j = start_index; j < start_index + num_chunks; ++j)
 144                                 g_assert (section->free_chunk_map [j]);
 145                 }
 146         }
 147
 148         g_assert (los_memory_usage == memory_usage);
 149 }
 150 #endif
 151
 152 static void
 153 add_free_chunk (LOSFreeChunks *free_chunks, size_t size)
 154 {
 155         size_t num_chunks = size >> LOS_CHUNK_BITS;
 156
 157         free_chunks->size = size;
 158
 159         if (num_chunks >= LOS_NUM_FAST_SIZES)
 160                 num_chunks = 0;
 161         free_chunks->next_size = los_fast_free_lists [num_chunks];
 162         los_fast_free_lists [num_chunks] = free_chunks;
 163 }
 164
 165 static LOSFreeChunks*
 166 get_from_size_list (LOSFreeChunks **list, size_t size)
 167 {
 168         LOSFreeChunks *free_chunks = NULL;
 169         LOSSection *section;
 170         size_t i, num_chunks, start_index;
 171
 172
 173         g_assert ((size & (LOS_CHUNK_SIZE - 1)) == 0);
 174
 175         while (*list) {
 176                 free_chunks = *list;
 177                 if (free_chunks->size >= size)
 178                         break;
 179                 list = &(*list)->next_size;
 180         }
 181
 182         if (!*list)
 183                 return NULL;
 184
 185         *list = free_chunks->next_size;
 186
 187         if (free_chunks->size > size)
 188                 add_free_chunk ((LOSFreeChunks*)((char*)free_chunks + size), free_chunks->size - size);
 189
 190         num_chunks = size >> LOS_CHUNK_BITS;
 191
 192         section = LOS_SECTION_FOR_OBJ (free_chunks);
 193
 194         start_index = LOS_CHUNK_INDEX (free_chunks, section);
 195         for (i = start_index; i < start_index + num_chunks; ++i) {
 196                 g_assert (section->free_chunk_map [i]);
 197                 section->free_chunk_map [i] = 0;
 198         }
 199
 200         section->num_free_chunks -= size >> LOS_CHUNK_BITS;
 201         g_assert (section->num_free_chunks >= 0);
 202
 203         return free_chunks;
 204 }
 205
 206 static LOSObject*
 207 randomize_los_object_start (gpointer addr, size_t obj_size, size_t alloced_size, size_t addr_alignment)
 208 {
 209         size_t offset = 0;
 210         if (alloced_size != obj_size) {
 211                 /*
 212                  * We want to get a random offset between 0 and (alloced_size - obj_size)
 213                  * We do a prime multiplication to avoid usage of functions which might not
 214                  * be thread/signal safe (like rand ()). We subtract 1 to avoid common
 215                  * power by 2 factors.
 216                  */
 217                 offset = SGEN_ALIGN_DOWN ((((size_t)addr - 1) * 2654435761u) % (alloced_size - obj_size));
 218         }
 219         SGEN_ASSERT (0, (alloced_size - obj_size) < addr_alignment, "Why are we wasting one entire chunk for a los object ?");
 220         /* Randomize the location within the reserved chunks to improve cache performance */
 221         return (LOSObject*)((guint8*)addr + offset);
 222
 223 }
 224
 225 static LOSObject*
 226 get_los_section_memory (size_t size)
 227 {
 228         LOSSection *section;
 229         LOSFreeChunks *free_chunks;
 230         size_t num_chunks;
 231         size_t obj_size = size;
 232
 233         size = SGEN_ALIGN_UP_TO (size, LOS_CHUNK_SIZE);
 234
 235         num_chunks = size >> LOS_CHUNK_BITS;
 236
 237         g_assert (size > 0 && size - sizeof (LOSObject) <= LOS_SECTION_OBJECT_LIMIT);
 238         g_assert (num_chunks > 0);
 239
 240  retry:
 241         if (num_chunks >= LOS_NUM_FAST_SIZES) {
 242                 free_chunks = get_from_size_list (&los_fast_free_lists [0], size);
 243         } else {
 244                 size_t i;
 245                 for (i = num_chunks; i < LOS_NUM_FAST_SIZES; ++i) {
 246                         free_chunks = get_from_size_list (&los_fast_free_lists [i], size);
 247                         if (free_chunks)
 248                                 break;
 249                 }
 250                 if (!free_chunks)
 251                         free_chunks = get_from_size_list (&los_fast_free_lists [0], size);
 252         }
 253
 254         if (free_chunks) {
 255                 return randomize_los_object_start (free_chunks, obj_size, size, LOS_CHUNK_SIZE);
 256         }
 257
 258         if (!sgen_memgov_try_alloc_space (LOS_SECTION_SIZE, SPACE_LOS))
 259                 return NULL;
 260
 261         section = (LOSSection *)sgen_alloc_os_memory_aligned (LOS_SECTION_SIZE, LOS_SECTION_SIZE, (SgenAllocFlags)(SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE), NULL);
 262
 263         if (!section)
 264                 return NULL;
 265
 266         free_chunks = (LOSFreeChunks*)((char*)section + LOS_CHUNK_SIZE);
 267         free_chunks->size = LOS_SECTION_SIZE - LOS_CHUNK_SIZE;
 268         free_chunks->next_size = los_fast_free_lists [0];
 269         los_fast_free_lists [0] = free_chunks;
 270
 271         section->num_free_chunks = LOS_SECTION_NUM_CHUNKS;
 272
 273         section->free_chunk_map = (unsigned char*)section + sizeof (LOSSection);
 274         g_assert (sizeof (LOSSection) + LOS_SECTION_NUM_CHUNKS + 1 <= LOS_CHUNK_SIZE);
 275         section->free_chunk_map [0] = 0;
 276         memset (section->free_chunk_map + 1, 1, LOS_SECTION_NUM_CHUNKS);
 277
 278         section->next = los_sections;
 279         los_sections = section;
 280
 281         ++los_num_sections;
 282
 283         goto retry;
 284 }
 285
 286 static void
 287 free_los_section_memory (LOSObject *obj, size_t size)
 288 {
 289         LOSSection *section = LOS_SECTION_FOR_OBJ (obj);
 290         size_t num_chunks, i, start_index;
 291
 292         size = SGEN_ALIGN_UP_TO (size, LOS_CHUNK_SIZE);
 293
 294         num_chunks = size >> LOS_CHUNK_BITS;
 295
 296         g_assert (size > 0 && size - sizeof (LOSObject) <= LOS_SECTION_OBJECT_LIMIT);
 297         g_assert (num_chunks > 0);
 298
 299         section->num_free_chunks += num_chunks;
 300         g_assert (section->num_free_chunks <= LOS_SECTION_NUM_CHUNKS);
 301
 302         /*
 303          * We could free the LOS section here if it's empty, but we
 304          * can't unless we also remove its free chunks from the fast
 305          * free lists.  Instead, we do it in los_sweep().
 306          */
 307
 308         start_index = LOS_CHUNK_INDEX (obj, section);
 309         for (i = start_index; i < start_index + num_chunks; ++i) {
 310                 g_assert (!section->free_chunk_map [i]);
 311                 section->free_chunk_map [i] = 1;
 312         }
 313
 314         add_free_chunk ((LOSFreeChunks*)SGEN_ALIGN_DOWN_TO ((mword)obj, LOS_CHUNK_SIZE), size);
 315 }
 316
 317 void
 318 sgen_los_free_object (LOSObject *obj)
 319 {
 320         SGEN_ASSERT (0, !obj->cardtable_mod_union, "We should never free a LOS object with a mod-union table.");
 321
 322 #ifndef LOS_DUMMY
 323         mword size = sgen_los_object_size (obj);
 324         SGEN_LOG (4, "Freed large object %p, size %lu", obj->data, (unsigned long)size);
 325         binary_protocol_empty (obj->data, size);
 326
 327         los_memory_usage -= size;
 328         los_num_objects--;
 329
 330 #ifdef USE_MALLOC
 331         free (obj);
 332 #else
 333         if (size > LOS_SECTION_OBJECT_LIMIT) {
 334                 int pagesize = mono_pagesize ();
 335                 size += sizeof (LOSObject);
 336                 size = SGEN_ALIGN_UP_TO (size, pagesize);
 337                 sgen_free_os_memory ((gpointer)SGEN_ALIGN_DOWN_TO ((mword)obj, pagesize), size, SGEN_ALLOC_HEAP);
 338                 sgen_memgov_release_space (size, SPACE_LOS);
 339         } else {
 340                 free_los_section_memory (obj, size + sizeof (LOSObject));
 341 #ifdef LOS_CONSISTENCY_CHECKS
 342                 los_consistency_check ();
 343 #endif
 344         }
 345 #endif
 346 #endif
 347 }
 348
 349 /*
 350  * Objects with size >= MAX_SMALL_SIZE are allocated in the large object space.
 351  * They are currently kept track of with a linked list.
 352  * They don't move, so there is no need to pin them during collection
 353  * and we avoid the memcpy overhead.
 354  */
 355 void*
 356 sgen_los_alloc_large_inner (GCVTable vtable, size_t size)
 357 {
 358         LOSObject *obj = NULL;
 359         void **vtslot;
 360
 361         g_assert (size > SGEN_MAX_SMALL_OBJ_SIZE);
 362         g_assert ((size & 1) == 0);
 363
 364         /*
 365          * size + sizeof (LOSObject) <= SSIZE_MAX - (mono_pagesize () - 1)
 366          *
 367          * therefore:
 368          *
 369          * size <= SSIZE_MAX - (mono_pagesize () - 1) - sizeof (LOSObject)
 370          */
 371         if (size > SSIZE_MAX - (mono_pagesize () - 1) - sizeof (LOSObject))
 372                 return NULL;
 373
 374 #ifdef LOS_DUMMY
 375         if (!los_segment)
 376                 los_segment = sgen_alloc_os_memory (LOS_SEGMENT_SIZE, SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE, NULL);
 377         los_segment_index = ALIGN_UP (los_segment_index);
 378
 379         obj = (LOSObject*)(los_segment + los_segment_index);
 380         los_segment_index += size + sizeof (LOSObject);
 381         g_assert (los_segment_index <= LOS_SEGMENT_SIZE);
 382 #else
 383         sgen_ensure_free_space (size, GENERATION_OLD);
 384
 385 #ifdef USE_MALLOC
 386         obj = malloc (size + sizeof (LOSObject));
 387         memset (obj, 0, size + sizeof (LOSObject));
 388 #else
 389         if (size > LOS_SECTION_OBJECT_LIMIT) {
 390                 size_t obj_size = size + sizeof (LOSObject);
 391                 int pagesize = mono_pagesize ();
 392                 size_t alloc_size = SGEN_ALIGN_UP_TO (obj_size, pagesize);
 393                 if (sgen_memgov_try_alloc_space (alloc_size, SPACE_LOS)) {
 394                         obj = (LOSObject *)sgen_alloc_os_memory (alloc_size, (SgenAllocFlags)(SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE), NULL);
 395                         if (obj)
 396                                 obj = randomize_los_object_start (obj, obj_size, alloc_size, pagesize);
 397                 }
 398         } else {
 399                 obj = get_los_section_memory (size + sizeof (LOSObject));
 400                 if (obj)
 401                         memset (obj, 0, size + sizeof (LOSObject));
 402         }
 403 #endif
 404 #endif
 405         if (!obj)
 406                 return NULL;
 407         g_assert (!((mword)obj->data & (SGEN_ALLOC_ALIGN - 1)));
 408         obj->size = size;
 409         vtslot = (void**)obj->data;
 410         *vtslot = vtable;
 411         sgen_update_heap_boundaries ((mword)obj->data, (mword)obj->data + size);
 412         obj->next = los_object_list;
 413         los_object_list = obj;
 414         los_memory_usage += size;
 415         los_num_objects++;
 416         SGEN_LOG (4, "Allocated large object %p, vtable: %p (%s), size: %zd", obj->data, vtable, sgen_client_vtable_get_name (vtable), size);
 417         binary_protocol_alloc (obj->data, vtable, size, sgen_client_get_provenance ());
 418
 419 #ifdef LOS_CONSISTENCY_CHECK
 420         los_consistency_check ();
 421 #endif
 422
 423         return obj->data;
 424 }
 425
 426 static void sgen_los_unpin_object (GCObject *data);
 427
 428 void
 429 sgen_los_sweep (void)
 430 {
 431         LOSObject *bigobj, *prevbo;
 432         LOSSection *section, *prev;
 433         int i;
 434         int num_sections = 0;
 435
 436         /* sweep the big objects list */
 437         prevbo = NULL;
 438         for (bigobj = los_object_list; bigobj;) {
 439                 SGEN_ASSERT (0, !SGEN_OBJECT_IS_PINNED (bigobj->data), "Who pinned a LOS object?");
 440
 441                 if (bigobj->cardtable_mod_union) {
 442                         sgen_card_table_free_mod_union (bigobj->cardtable_mod_union, (char*)bigobj->data, sgen_los_object_size (bigobj));
 443                         bigobj->cardtable_mod_union = NULL;
 444                 }
 445
 446                 if (sgen_los_object_is_pinned (bigobj->data)) {
 447                         sgen_los_unpin_object (bigobj->data);
 448                         sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
 449                 } else {
 450                         LOSObject *to_free;
 451                         /* not referenced anywhere, so we can free it */
 452                         if (prevbo)
 453                                 prevbo->next = bigobj->next;
 454                         else
 455                                 los_object_list = bigobj->next;
 456                         to_free = bigobj;
 457                         bigobj = bigobj->next;
 458                         sgen_los_free_object (to_free);
 459                         continue;
 460                 }
 461                 prevbo = bigobj;
 462                 bigobj = bigobj->next;
 463         }
 464
 465         /* Try to free memory */
 466         for (i = 0; i < LOS_NUM_FAST_SIZES; ++i)
 467                 los_fast_free_lists [i] = NULL;
 468
 469         prev = NULL;
 470         section = los_sections;
 471         while (section) {
 472                 if (section->num_free_chunks == LOS_SECTION_NUM_CHUNKS) {
 473                         LOSSection *next = section->next;
 474                         if (prev)
 475                                 prev->next = next;
 476                         else
 477                                 los_sections = next;
 478                         sgen_free_os_memory (section, LOS_SECTION_SIZE, SGEN_ALLOC_HEAP);
 479                         sgen_memgov_release_space (LOS_SECTION_SIZE, SPACE_LOS);
 480                         section = next;
 481                         --los_num_sections;
 482                         continue;
 483                 }
 484
 485                 for (i = 0; i <= LOS_SECTION_NUM_CHUNKS; ++i) {
 486                         if (section->free_chunk_map [i]) {
 487                                 int j;
 488                                 for (j = i + 1; j <= LOS_SECTION_NUM_CHUNKS && section->free_chunk_map [j]; ++j)
 489                                         ;
 490                                 add_free_chunk ((LOSFreeChunks*)((char*)section + (i << LOS_CHUNK_BITS)), (j - i) << LOS_CHUNK_BITS);
 491                                 i = j - 1;
 492                         }
 493                 }
 494
 495                 prev = section;
 496                 section = section->next;
 497
 498                 ++num_sections;
 499         }
 500
 501 #ifdef LOS_CONSISTENCY_CHECK
 502         los_consistency_check ();
 503 #endif
 504
 505         /*
 506         g_print ("LOS sections: %d  objects: %d  usage: %d\n", num_sections, los_num_objects, los_memory_usage);
 507         for (i = 0; i < LOS_NUM_FAST_SIZES; ++i) {
 508                 int num_chunks = 0;
 509                 LOSFreeChunks *free_chunks;
 510                 for (free_chunks = los_fast_free_lists [i]; free_chunks; free_chunks = free_chunks->next_size)
 511                         ++num_chunks;
 512                 g_print ("  %d: %d\n", i, num_chunks);
 513         }
 514         */
 515
 516         g_assert (los_num_sections == num_sections);
 517 }
 518
 519 gboolean
 520 sgen_ptr_is_in_los (char *ptr, char **start)
 521 {
 522         LOSObject *obj;
 523
 524         *start = NULL;
 525         for (obj = los_object_list; obj; obj = obj->next) {
 526                 char *end = (char*)obj->data + sgen_los_object_size (obj);
 527
 528                 if (ptr >= (char*)obj->data && ptr < end) {
 529                         *start = (char*)obj->data;
 530                         return TRUE;
 531                 }
 532         }
 533         return FALSE;
 534 }
 535
 536 void
 537 sgen_los_iterate_objects (IterateObjectCallbackFunc cb, void *user_data)
 538 {
 539         LOSObject *obj;
 540
 541         for (obj = los_object_list; obj; obj = obj->next)
 542                 cb (obj->data, sgen_los_object_size (obj), user_data);
 543 }
 544
 545 gboolean
 546 sgen_los_is_valid_object (char *object)
 547 {
 548         LOSObject *obj;
 549
 550         for (obj = los_object_list; obj; obj = obj->next) {
 551                 if ((char*)obj->data == object)
 552                         return TRUE;
 553         }
 554         return FALSE;
 555 }
 556
 557 gboolean
 558 mono_sgen_los_describe_pointer (char *ptr)
 559 {
 560         LOSObject *obj;
 561
 562         for (obj = los_object_list; obj; obj = obj->next) {
 563                 const char *los_kind;
 564                 mword size;
 565                 gboolean pinned;
 566
 567                 if ((char*)obj->data > ptr || (char*)obj->data + sgen_los_object_size (obj) <= ptr)
 568                         continue;
 569
 570                 size = sgen_los_object_size (obj);
 571                 pinned = sgen_los_object_is_pinned (obj->data);
 572
 573                 if (size > LOS_SECTION_OBJECT_LIMIT)
 574                         los_kind = "huge-los-ptr";
 575                 else
 576                         los_kind = "los-ptr";
 577
 578                 if ((char*)obj->data == ptr) {
 579                         SGEN_LOG (0, "%s (size %d pin %d)\n", los_kind, (int)size, pinned ? 1 : 0);
 580                 } else {
 581                         SGEN_LOG (0, "%s (interior-ptr offset %zd size %d pin %d)",
 582                                         los_kind, ptr - (char*)obj->data, (int)size, pinned ? 1 : 0);
 583                 }
 584
 585                 return TRUE;
 586         }
 587         return FALSE;
 588 }
 589
 590 void
 591 sgen_los_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
 592 {
 593         LOSObject *obj;
 594         for (obj = los_object_list; obj; obj = obj->next) {
 595                 GCVTable vt = SGEN_LOAD_VTABLE (obj->data);
 596                 if (SGEN_VTABLE_HAS_REFERENCES (vt))
 597                         callback ((mword)obj->data, sgen_los_object_size (obj));
 598         }
 599 }
 600
 601 static guint8*
 602 get_cardtable_mod_union_for_object (LOSObject *obj)
 603 {
 604         mword size = sgen_los_object_size (obj);
 605         guint8 *mod_union = obj->cardtable_mod_union;
 606         guint8 *other;
 607         if (mod_union)
 608                 return mod_union;
 609         mod_union = sgen_card_table_alloc_mod_union ((char*)obj->data, size);
 610         other = (guint8 *)SGEN_CAS_PTR ((gpointer*)&obj->cardtable_mod_union, mod_union, NULL);
 611         if (!other) {
 612                 SGEN_ASSERT (0, obj->cardtable_mod_union == mod_union, "Why did CAS not replace?");
 613                 return mod_union;
 614         }
 615         sgen_card_table_free_mod_union (mod_union, (char*)obj->data, size);
 616         return other;
 617 }
 618
 619 void
 620 sgen_los_scan_card_table (gboolean mod_union, ScanCopyContext ctx)
 621 {
 622         LOSObject *obj;
 623
 624         binary_protocol_los_card_table_scan_start (sgen_timestamp (), mod_union);
 625         for (obj = los_object_list; obj; obj = obj->next) {
 626                 guint8 *cards;
 627
 628                 if (!SGEN_OBJECT_HAS_REFERENCES (obj->data))
 629                         continue;
 630
 631                 if (mod_union) {
 632                         if (!sgen_los_object_is_pinned (obj->data))
 633                                 continue;
 634
 635                         cards = get_cardtable_mod_union_for_object (obj);
 636                         g_assert (cards);
 637                 } else {
 638                         cards = NULL;
 639                 }
 640
 641                 sgen_cardtable_scan_object (obj->data, sgen_los_object_size (obj), cards, mod_union, ctx);
 642         }
 643         binary_protocol_los_card_table_scan_end (sgen_timestamp (), mod_union);
 644 }
 645
 646 void
 647 sgen_los_count_cards (long long *num_total_cards, long long *num_marked_cards)
 648 {
 649         LOSObject *obj;
 650         long long total_cards = 0;
 651         long long marked_cards = 0;
 652
 653         for (obj = los_object_list; obj; obj = obj->next) {
 654                 int i;
 655                 guint8 *cards = sgen_card_table_get_card_scan_address ((mword) obj->data);
 656                 guint8 *cards_end = sgen_card_table_get_card_scan_address ((mword) obj->data + sgen_los_object_size (obj) - 1);
 657                 mword num_cards = (cards_end - cards) + 1;
 658
 659                 if (!SGEN_OBJECT_HAS_REFERENCES (obj->data))
 660                         continue;
 661
 662                 total_cards += num_cards;
 663                 for (i = 0; i < num_cards; ++i) {
 664                         if (cards [i])
 665                                 ++marked_cards;
 666                 }
 667         }
 668
 669         *num_total_cards = total_cards;
 670         *num_marked_cards = marked_cards;
 671 }
 672
 673 void
 674 sgen_los_update_cardtable_mod_union (void)
 675 {
 676         LOSObject *obj;
 677
 678         for (obj = los_object_list; obj; obj = obj->next) {
 679                 if (!SGEN_OBJECT_HAS_REFERENCES (obj->data))
 680                         continue;
 681                 sgen_card_table_update_mod_union (get_cardtable_mod_union_for_object (obj),
 682                                 (char*)obj->data, sgen_los_object_size (obj), NULL);
 683         }
 684 }
 685
 686 LOSObject*
 687 sgen_los_header_for_object (GCObject *data)
 688 {
 689 #if _MSC_VER
 690         return (LOSObject*)((char*)data - (int)(&(((LOSObject*)0)->data)));
 691 #else
 692         return (LOSObject*)((char*)data - sizeof (LOSObject));
 693 #endif
 694 }
 695
 696 void
 697 sgen_los_pin_object (GCObject *data)
 698 {
 699         LOSObject *obj = sgen_los_header_for_object (data);
 700         obj->size = obj->size | 1;
 701         binary_protocol_pin (data, (gpointer)SGEN_LOAD_VTABLE (data), sgen_safe_object_get_size (data));
 702 }
 703
 704 static void
 705 sgen_los_unpin_object (GCObject *data)
 706 {
 707         LOSObject *obj = sgen_los_header_for_object (data);
 708         obj->size = sgen_los_object_size (obj);
 709 }
 710
 711 gboolean
 712 sgen_los_object_is_pinned (GCObject *data)
 713 {
 714         LOSObject *obj = sgen_los_header_for_object (data);
 715         return obj->size & 1;
 716 }
 717
 718 void
 719 sgen_los_mark_mod_union_card (GCObject *mono_obj, void **ptr)
 720 {
 721         LOSObject *obj = sgen_los_header_for_object (mono_obj);
 722         guint8 *mod_union = get_cardtable_mod_union_for_object (obj);
 723         /* The LOSObject structure is not represented within the card space */
 724         size_t offset = sgen_card_table_get_card_offset ((char*)ptr, (char*)sgen_card_table_align_pointer((char*)mono_obj));
 725         SGEN_ASSERT (0, mod_union, "FIXME: optionally allocate the mod union if it's not here and CAS it in.");
 726         mod_union [offset] = 1;
 727 }
 728
 729 #endif /* HAVE_SGEN_GC */