mono/metadata/sgen-cardtable.c

   1 /*
   2  * sgen-cardtable.c: Card table implementation for sgen
   3  *
   4  * Author:
   5  *      Rodrigo Kumpera (rkumpera@novell.com)
   6  *
   7  * Copyright 2001-2003 Ximian, Inc
   8  * Copyright 2003-2010 Novell, Inc.
   9  * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
  10  * Copyright (C) 2012 Xamarin Inc
  11  *
  12  * This library is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Library General Public
  14  * License 2.0 as published by the Free Software Foundation;
  15  *
  16  * This library is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * Library General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Library General Public
  22  * License 2.0 along with this library; if not, write to the Free
  23  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #include "config.h"
  27 #ifdef HAVE_SGEN_GC
  28
  29 #include "metadata/sgen-gc.h"
  30 #include "metadata/sgen-cardtable.h"
  31 #include "metadata/sgen-memory-governor.h"
  32 #include "metadata/sgen-protocol.h"
  33 #include "metadata/sgen-layout-stats.h"
  34 #include "utils/mono-counters.h"
  35 #include "utils/mono-time.h"
  36 #include "utils/mono-memory-model.h"
  37
  38 //#define CARDTABLE_STATS
  39
  40 #ifdef HAVE_UNISTD_H
  41 #include <unistd.h>
  42 #endif
  43 #ifdef HAVE_SYS_MMAN_H
  44 #include <sys/mman.h>
  45 #endif
  46 #include <sys/types.h>
  47
  48 #define ARRAY_OBJ_INDEX(ptr,array,elem_size) (((char*)(ptr) - ((char*)(array) + G_STRUCT_OFFSET (MonoArray, vector))) / (elem_size))
  49
  50 guint8 *sgen_cardtable;
  51
  52 static gboolean need_mod_union;
  53
  54 #ifdef HEAVY_STATISTICS
  55 guint64 marked_cards;
  56 guint64 scanned_cards;
  57 guint64 scanned_objects;
  58 guint64 remarked_cards;
  59
  60 static guint64 los_marked_cards;
  61 static guint64 large_objects;
  62 static guint64 bloby_objects;
  63 static guint64 los_array_cards;
  64 static guint64 los_array_remsets;
  65
  66 #endif
  67 static guint64 major_card_scan_time;
  68 static guint64 los_card_scan_time;
  69
  70 static guint64 last_major_scan_time;
  71 static guint64 last_los_scan_time;
  72
  73 static void sgen_card_tables_collect_stats (gboolean begin);
  74
  75
  76 /*WARNING: This function returns the number of cards regardless of overflow in case of overlapping cards.*/
  77 static mword
  78 cards_in_range (mword address, mword size)
  79 {
  80         mword end = address + MAX (1, size) - 1;
  81         return (end >> CARD_BITS) - (address >> CARD_BITS) + 1;
  82 }
  83
  84 static void
  85 sgen_card_table_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
  86 {
  87         *(void**)field_ptr = value;
  88         if (need_mod_union || sgen_ptr_in_nursery (value))
  89                 sgen_card_table_mark_address ((mword)field_ptr);
  90         sgen_dummy_use (value);
  91 }
  92
  93 static void
  94 sgen_card_table_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
  95 {
  96         *(void**)slot_ptr = value;
  97         if (need_mod_union || sgen_ptr_in_nursery (value))
  98                 sgen_card_table_mark_address ((mword)slot_ptr);
  99         sgen_dummy_use (value);
 100 }
 101
 102 static void
 103 sgen_card_table_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
 104 {
 105         gpointer *dest = dest_ptr;
 106         gpointer *src = src_ptr;
 107
 108         /*overlapping that required backward copying*/
 109         if (src < dest && (src + count) > dest) {
 110                 gpointer *start = dest;
 111                 dest += count - 1;
 112                 src += count - 1;
 113
 114                 for (; dest >= start; --src, --dest) {
 115                         gpointer value = *src;
 116                         SGEN_UPDATE_REFERENCE_ALLOW_NULL (dest, value);
 117                         if (need_mod_union || sgen_ptr_in_nursery (value))
 118                                 sgen_card_table_mark_address ((mword)dest);
 119                         sgen_dummy_use (value);
 120                 }
 121         } else {
 122                 gpointer *end = dest + count;
 123                 for (; dest < end; ++src, ++dest) {
 124                         gpointer value = *src;
 125                         SGEN_UPDATE_REFERENCE_ALLOW_NULL (dest, value);
 126                         if (need_mod_union || sgen_ptr_in_nursery (value))
 127                                 sgen_card_table_mark_address ((mword)dest);
 128                         sgen_dummy_use (value);
 129                 }
 130         }
 131 }
 132
 133 static void
 134 sgen_card_table_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
 135 {
 136         size_t element_size = mono_class_value_size (klass, NULL);
 137         size_t size = count * element_size;
 138
 139 #ifdef DISABLE_CRITICAL_REGION
 140         LOCK_GC;
 141 #else
 142         TLAB_ACCESS_INIT;
 143         ENTER_CRITICAL_REGION;
 144 #endif
 145         mono_gc_memmove_atomic (dest, src, size);
 146         sgen_card_table_mark_range ((mword)dest, size);
 147 #ifdef DISABLE_CRITICAL_REGION
 148         UNLOCK_GC;
 149 #else
 150         EXIT_CRITICAL_REGION;
 151 #endif
 152 }
 153
 154 static void
 155 sgen_card_table_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
 156 {
 157         int size = mono_object_class (obj)->instance_size;
 158
 159 #ifdef DISABLE_CRITICAL_REGION
 160         LOCK_GC;
 161 #else
 162         TLAB_ACCESS_INIT;
 163         ENTER_CRITICAL_REGION;
 164 #endif
 165         mono_gc_memmove_aligned ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
 166                         size - sizeof (MonoObject));
 167         sgen_card_table_mark_range ((mword)obj, size);
 168 #ifdef DISABLE_CRITICAL_REGION
 169         UNLOCK_GC;
 170 #else
 171         EXIT_CRITICAL_REGION;
 172 #endif
 173 }
 174
 175 static void
 176 sgen_card_table_wbarrier_generic_nostore (gpointer ptr)
 177 {
 178         sgen_card_table_mark_address ((mword)ptr);
 179 }
 180
 181 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 182
 183 guint8 *sgen_shadow_cardtable;
 184
 185 #define SGEN_SHADOW_CARDTABLE_END (sgen_shadow_cardtable + CARD_COUNT_IN_BYTES)
 186 #define SGEN_CARDTABLE_END (sgen_cardtable + CARD_COUNT_IN_BYTES)
 187
 188 static gboolean
 189 sgen_card_table_region_begin_scanning (mword start, mword end)
 190 {
 191         /*XXX this can be improved to work on words and have a single loop induction var */
 192         while (start <= end) {
 193                 if (sgen_card_table_card_begin_scanning (start))
 194                         return TRUE;
 195                 start += CARD_SIZE_IN_BYTES;
 196         }
 197         return FALSE;
 198 }
 199
 200 #else
 201
 202 static gboolean
 203 sgen_card_table_region_begin_scanning (mword start, mword size)
 204 {
 205         gboolean res = FALSE;
 206         guint8 *card = sgen_card_table_get_card_address (start);
 207         guint8 *end = card + cards_in_range (start, size);
 208
 209         /*XXX this can be improved to work on words and have a branchless body */
 210         while (card != end) {
 211                 if (*card++) {
 212                         res = TRUE;
 213                         break;
 214                 }
 215         }
 216
 217         memset (sgen_card_table_get_card_address (start), 0, size >> CARD_BITS);
 218
 219         return res;
 220 }
 221
 222 #endif
 223
 224 /*FIXME this assumes that major blocks are multiple of 4K which is pretty reasonable */
 225 gboolean
 226 sgen_card_table_get_card_data (guint8 *data_dest, mword address, mword cards)
 227 {
 228         mword *start = (mword*)sgen_card_table_get_card_scan_address (address);
 229         mword *dest = (mword*)data_dest;
 230         mword *end = (mword*)(data_dest + cards);
 231         mword mask = 0;
 232
 233         for (; dest < end; ++dest, ++start) {
 234                 mword v = *start;
 235                 *dest = v;
 236                 mask |= v;
 237
 238 #ifndef SGEN_HAVE_OVERLAPPING_CARDS
 239                 *start = 0;
 240 #endif
 241         }
 242
 243         return mask != 0;
 244 }
 245
 246 void*
 247 sgen_card_table_align_pointer (void *ptr)
 248 {
 249         return (void*)((mword)ptr & ~(CARD_SIZE_IN_BYTES - 1));
 250 }
 251
 252 void
 253 sgen_card_table_mark_range (mword address, mword size)
 254 {
 255         memset (sgen_card_table_get_card_address (address), 1, cards_in_range (address, size));
 256 }
 257
 258 static gboolean
 259 sgen_card_table_is_range_marked (guint8 *cards, mword address, mword size)
 260 {
 261         guint8 *end = cards + cards_in_range (address, size);
 262
 263         /*This is safe since this function is only called by code that only passes continuous card blocks*/
 264         while (cards != end) {
 265                 if (*cards++)
 266                         return TRUE;
 267         }
 268         return FALSE;
 269
 270 }
 271
 272 static void
 273 sgen_card_table_record_pointer (gpointer address)
 274 {
 275         *sgen_card_table_get_card_address ((mword)address) = 1;
 276 }
 277
 278 static gboolean
 279 sgen_card_table_find_address (char *addr)
 280 {
 281         return sgen_card_table_address_is_marked ((mword)addr);
 282 }
 283
 284 static gboolean
 285 sgen_card_table_find_address_with_cards (char *cards_start, guint8 *cards, char *addr)
 286 {
 287         cards_start = sgen_card_table_align_pointer (cards_start);
 288         return cards [(addr - cards_start) >> CARD_BITS];
 289 }
 290
 291 static void
 292 update_mod_union (guint8 *dest, gboolean init, guint8 *start_card, size_t num_cards)
 293 {
 294         if (init) {
 295                 memcpy (dest, start_card, num_cards);
 296         } else {
 297                 int i;
 298                 for (i = 0; i < num_cards; ++i)
 299                         dest [i] |= start_card [i];
 300         }
 301 }
 302
 303 static guint8*
 304 alloc_mod_union (size_t num_cards)
 305 {
 306         return sgen_alloc_internal_dynamic (num_cards, INTERNAL_MEM_CARDTABLE_MOD_UNION, TRUE);
 307 }
 308
 309 guint8*
 310 sgen_card_table_update_mod_union_from_cards (guint8 *dest, guint8 *start_card, size_t num_cards)
 311 {
 312         gboolean init = dest == NULL;
 313
 314         if (init)
 315                 dest = alloc_mod_union (num_cards);
 316
 317         update_mod_union (dest, init, start_card, num_cards);
 318
 319         return dest;
 320 }
 321
 322 guint8*
 323 sgen_card_table_update_mod_union (guint8 *dest, char *obj, mword obj_size, size_t *out_num_cards)
 324 {
 325         guint8 *start_card = sgen_card_table_get_card_address ((mword)obj);
 326 #ifndef SGEN_HAVE_OVERLAPPING_CARDS
 327         guint8 *end_card = sgen_card_table_get_card_address ((mword)obj + obj_size - 1) + 1;
 328 #endif
 329         size_t num_cards;
 330         guint8 *result = NULL;
 331
 332 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 333         size_t rest;
 334
 335         rest = num_cards = cards_in_range ((mword) obj, obj_size);
 336
 337         while (start_card + rest > SGEN_CARDTABLE_END) {
 338                 size_t count = SGEN_CARDTABLE_END - start_card;
 339                 dest = sgen_card_table_update_mod_union_from_cards (dest, start_card, count);
 340                 if (!result)
 341                         result = dest;
 342                 dest += count;
 343                 rest -= count;
 344                 start_card = sgen_cardtable;
 345         }
 346         num_cards = rest;
 347 #else
 348         num_cards = end_card - start_card;
 349 #endif
 350
 351         dest = sgen_card_table_update_mod_union_from_cards (dest, start_card, num_cards);
 352         if (!result)
 353                 result = dest;
 354
 355         if (out_num_cards)
 356                 *out_num_cards = num_cards;
 357
 358         return result;
 359 }
 360
 361 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 362
 363 static void
 364 move_cards_to_shadow_table (mword start, mword size)
 365 {
 366         guint8 *from = sgen_card_table_get_card_address (start);
 367         guint8 *to = sgen_card_table_get_shadow_card_address (start);
 368         size_t bytes = cards_in_range (start, size);
 369
 370         if (bytes >= CARD_COUNT_IN_BYTES) {
 371                 memcpy (sgen_shadow_cardtable, sgen_cardtable, CARD_COUNT_IN_BYTES);
 372         } else if (to + bytes > SGEN_SHADOW_CARDTABLE_END) {
 373                 size_t first_chunk = SGEN_SHADOW_CARDTABLE_END - to;
 374                 size_t second_chunk = MIN (CARD_COUNT_IN_BYTES, bytes) - first_chunk;
 375
 376                 memcpy (to, from, first_chunk);
 377                 memcpy (sgen_shadow_cardtable, sgen_cardtable, second_chunk);
 378         } else {
 379                 memcpy (to, from, bytes);
 380         }
 381 }
 382
 383 static void
 384 clear_cards (mword start, mword size)
 385 {
 386         guint8 *addr = sgen_card_table_get_card_address (start);
 387         size_t bytes = cards_in_range (start, size);
 388
 389         if (bytes >= CARD_COUNT_IN_BYTES) {
 390                 memset (sgen_cardtable, 0, CARD_COUNT_IN_BYTES);
 391         } else if (addr + bytes > SGEN_CARDTABLE_END) {
 392                 size_t first_chunk = SGEN_CARDTABLE_END - addr;
 393
 394                 memset (addr, 0, first_chunk);
 395                 memset (sgen_cardtable, 0, bytes - first_chunk);
 396         } else {
 397                 memset (addr, 0, bytes);
 398         }
 399 }
 400
 401
 402 #else
 403
 404 static void
 405 clear_cards (mword start, mword size)
 406 {
 407         memset (sgen_card_table_get_card_address (start), 0, cards_in_range (start, size));
 408 }
 409
 410
 411 #endif
 412
 413 static void
 414 sgen_card_table_prepare_for_major_collection (void)
 415 {
 416         /*XXX we could do this in 2 ways. using mincore or iterating over all sections/los objects */
 417         sgen_major_collector_iterate_live_block_ranges (clear_cards);
 418         sgen_los_iterate_live_block_ranges (clear_cards);
 419 }
 420
 421 static void
 422 sgen_card_table_finish_minor_collection (void)
 423 {
 424         sgen_card_tables_collect_stats (FALSE);
 425 }
 426
 427 static void
 428 sgen_card_table_finish_scan_remsets (void *start_nursery, void *end_nursery, SgenGrayQueue *queue)
 429 {
 430         SGEN_TV_DECLARE (atv);
 431         SGEN_TV_DECLARE (btv);
 432
 433         sgen_card_tables_collect_stats (TRUE);
 434
 435 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 436         /*FIXME we should have a bit on each block/los object telling if the object have marked cards.*/
 437         /*First we copy*/
 438         sgen_major_collector_iterate_live_block_ranges (move_cards_to_shadow_table);
 439         sgen_los_iterate_live_block_ranges (move_cards_to_shadow_table);
 440
 441         /*Then we clear*/
 442         sgen_card_table_prepare_for_major_collection ();
 443 #endif
 444         SGEN_TV_GETTIME (atv);
 445         sgen_major_collector_scan_card_table (queue);
 446         SGEN_TV_GETTIME (btv);
 447         last_major_scan_time = SGEN_TV_ELAPSED (atv, btv);
 448         major_card_scan_time += last_major_scan_time;
 449         sgen_los_scan_card_table (FALSE, queue);
 450         SGEN_TV_GETTIME (atv);
 451         last_los_scan_time = SGEN_TV_ELAPSED (btv, atv);
 452         los_card_scan_time += last_los_scan_time;
 453 }
 454
 455 guint8*
 456 mono_gc_get_card_table (int *shift_bits, gpointer *mask)
 457 {
 458 #ifndef MANAGED_WBARRIER
 459         return NULL;
 460 #else
 461         if (!sgen_cardtable)
 462                 return NULL;
 463
 464         *shift_bits = CARD_BITS;
 465 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 466         *mask = (gpointer)CARD_MASK;
 467 #else
 468         *mask = NULL;
 469 #endif
 470
 471         return sgen_cardtable;
 472 #endif
 473 }
 474
 475 gboolean
 476 mono_gc_card_table_nursery_check (void)
 477 {
 478         return !major_collector.is_concurrent;
 479 }
 480
 481 #if 0
 482 void
 483 sgen_card_table_dump_obj_card (char *object, size_t size, void *dummy)
 484 {
 485         guint8 *start = sgen_card_table_get_card_scan_address (object);
 486         guint8 *end = start + cards_in_range (object, size);
 487         int cnt = 0;
 488         printf ("--obj %p %d cards [%p %p]--", object, size, start, end);
 489         for (; start < end; ++start) {
 490                 if (cnt == 0)
 491                         printf ("\n\t[%p] ", start);
 492                 printf ("%x ", *start);
 493                 ++cnt;
 494                 if (cnt == 8)
 495                         cnt = 0;
 496         }
 497         printf ("\n");
 498 }
 499 #endif
 500
 501 #define MWORD_MASK (sizeof (mword) - 1)
 502
 503 static inline int
 504 find_card_offset (mword card)
 505 {
 506 /*XXX Use assembly as this generates some pretty bad code */
 507 #if defined(__i386__) && defined(__GNUC__)
 508         return  (__builtin_ffs (card) - 1) / 8;
 509 #elif defined(__x86_64__) && defined(__GNUC__)
 510         return (__builtin_ffsll (card) - 1) / 8;
 511 #elif defined(__s390x__)
 512         return (__builtin_ffsll (GUINT64_TO_LE(card)) - 1) / 8;
 513 #else
 514         int i;
 515         guint8 *ptr = (guint8 *) &card;
 516         for (i = 0; i < sizeof (mword); ++i) {
 517                 if (ptr[i])
 518                         return i;
 519         }
 520         return 0;
 521 #endif
 522 }
 523
 524 static guint8*
 525 find_next_card (guint8 *card_data, guint8 *end)
 526 {
 527         mword *cards, *cards_end;
 528         mword card;
 529
 530         while ((((mword)card_data) & MWORD_MASK) && card_data < end) {
 531                 if (*card_data)
 532                         return card_data;
 533                 ++card_data;
 534         }
 535
 536         if (card_data == end)
 537                 return end;
 538
 539         cards = (mword*)card_data;
 540         cards_end = (mword*)((mword)end & ~MWORD_MASK);
 541         while (cards < cards_end) {
 542                 card = *cards;
 543                 if (card)
 544                         return (guint8*)cards + find_card_offset (card);
 545                 ++cards;
 546         }
 547
 548         card_data = (guint8*)cards_end;
 549         while (card_data < end) {
 550                 if (*card_data)
 551                         return card_data;
 552                 ++card_data;
 553         }
 554
 555         return end;
 556 }
 557
 558 void
 559 sgen_cardtable_scan_object (char *obj, mword block_obj_size, guint8 *cards, gboolean mod_union, SgenGrayQueue *queue)
 560 {
 561         MonoVTable *vt = (MonoVTable*)SGEN_LOAD_VTABLE (obj);
 562         MonoClass *klass = vt->klass;
 563
 564         HEAVY_STAT (++large_objects);
 565
 566         if (!SGEN_VTABLE_HAS_REFERENCES (vt)) {
 567                 sgen_object_layout_scanned_bitmap (0);
 568                 return;
 569         }
 570
 571         if (vt->rank) {
 572                 guint8 *card_data, *card_base;
 573                 guint8 *card_data_end;
 574                 char *obj_start = sgen_card_table_align_pointer (obj);
 575                 mword obj_size = sgen_par_object_get_size (vt, (MonoObject*)obj);
 576                 char *obj_end = obj + obj_size;
 577                 size_t card_count;
 578                 size_t extra_idx = 0;
 579
 580                 MonoArray *arr = (MonoArray*)obj;
 581                 mword desc = (mword)klass->element_class->gc_descr;
 582                 int elem_size = mono_array_element_size (klass);
 583
 584 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 585                 guint8 *overflow_scan_end = NULL;
 586 #endif
 587
 588 #ifdef SGEN_OBJECT_LAYOUT_STATISTICS
 589                 if (klass->element_class->valuetype)
 590                         sgen_object_layout_scanned_vtype_array ();
 591                 else
 592                         sgen_object_layout_scanned_ref_array ();
 593 #endif
 594
 595                 if (cards)
 596                         card_data = cards;
 597                 else
 598                         card_data = sgen_card_table_get_card_scan_address ((mword)obj);
 599
 600                 card_base = card_data;
 601                 card_count = cards_in_range ((mword)obj, obj_size);
 602                 card_data_end = card_data + card_count;
 603
 604
 605 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 606                 /*Check for overflow and if so, setup to scan in two steps*/
 607                 if (!cards && card_data_end >= SGEN_SHADOW_CARDTABLE_END) {
 608                         overflow_scan_end = sgen_shadow_cardtable + (card_data_end - SGEN_SHADOW_CARDTABLE_END);
 609                         card_data_end = SGEN_SHADOW_CARDTABLE_END;
 610                 }
 611
 612 LOOP_HEAD:
 613 #endif
 614
 615                 card_data = find_next_card (card_data, card_data_end);
 616                 for (; card_data < card_data_end; card_data = find_next_card (card_data + 1, card_data_end)) {
 617                         size_t index;
 618                         size_t idx = (card_data - card_base) + extra_idx;
 619                         char *start = (char*)(obj_start + idx * CARD_SIZE_IN_BYTES);
 620                         char *card_end = start + CARD_SIZE_IN_BYTES;
 621                         char *first_elem, *elem;
 622
 623                         HEAVY_STAT (++los_marked_cards);
 624
 625                         if (!cards)
 626                                 sgen_card_table_prepare_card_for_scanning (card_data);
 627
 628                         card_end = MIN (card_end, obj_end);
 629
 630                         if (start <= (char*)arr->vector)
 631                                 index = 0;
 632                         else
 633                                 index = ARRAY_OBJ_INDEX (start, obj, elem_size);
 634
 635                         elem = first_elem = (char*)mono_array_addr_with_size_fast ((MonoArray*)obj, elem_size, index);
 636                         if (klass->element_class->valuetype) {
 637                                 ScanVTypeFunc scan_vtype_func = sgen_get_current_object_ops ()->scan_vtype;
 638
 639                                 for (; elem < card_end; elem += elem_size)
 640                                         scan_vtype_func (elem, desc, queue BINARY_PROTOCOL_ARG (elem_size));
 641                         } else {
 642                                 CopyOrMarkObjectFunc copy_func = sgen_get_current_object_ops ()->copy_or_mark_object;
 643
 644                                 HEAVY_STAT (++los_array_cards);
 645                                 for (; elem < card_end; elem += SIZEOF_VOID_P) {
 646                                         gpointer new, old = *(gpointer*)elem;
 647                                         if ((mod_union && old) || G_UNLIKELY (sgen_ptr_in_nursery (old))) {
 648                                                 HEAVY_STAT (++los_array_remsets);
 649                                                 copy_func ((void**)elem, queue);
 650                                                 new = *(gpointer*)elem;
 651                                                 if (G_UNLIKELY (sgen_ptr_in_nursery (new)))
 652                                                         sgen_add_to_global_remset (elem, new);
 653                                         }
 654                                 }
 655                         }
 656
 657                         binary_protocol_card_scan (first_elem, elem - first_elem);
 658                 }
 659
 660 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 661                 if (overflow_scan_end) {
 662                         extra_idx = card_data - card_base;
 663                         card_base = card_data = sgen_shadow_cardtable;
 664                         card_data_end = overflow_scan_end;
 665                         overflow_scan_end = NULL;
 666                         goto LOOP_HEAD;
 667                 }
 668 #endif
 669
 670         } else {
 671                 HEAVY_STAT (++bloby_objects);
 672                 if (cards) {
 673                         if (sgen_card_table_is_range_marked (cards, (mword)obj, block_obj_size))
 674                                 sgen_get_current_object_ops ()->scan_object (obj, sgen_obj_get_descriptor (obj), queue);
 675                 } else if (sgen_card_table_region_begin_scanning ((mword)obj, block_obj_size)) {
 676                         sgen_get_current_object_ops ()->scan_object (obj, sgen_obj_get_descriptor (obj), queue);
 677                 }
 678
 679                 binary_protocol_card_scan (obj, sgen_safe_object_get_size ((MonoObject*)obj));
 680         }
 681 }
 682
 683 #ifdef CARDTABLE_STATS
 684
 685 typedef struct {
 686         int total, marked, remarked, gc_marked;
 687 } card_stats;
 688
 689 static card_stats major_stats, los_stats;
 690 static card_stats *cur_stats;
 691
 692 static void
 693 count_marked_cards (mword start, mword size)
 694 {
 695         mword end = start + size;
 696         while (start <= end) {
 697                 guint8 card = *sgen_card_table_get_card_address (start);
 698                 ++cur_stats->total;
 699                 if (card)
 700                         ++cur_stats->marked;
 701                 if (card == 2)
 702                         ++cur_stats->gc_marked;
 703                 start += CARD_SIZE_IN_BYTES;
 704         }
 705 }
 706
 707 static void
 708 count_remarked_cards (mword start, mword size)
 709 {
 710         mword end = start + size;
 711         while (start <= end) {
 712                 if (sgen_card_table_address_is_marked (start)) {
 713                         ++cur_stats->remarked;
 714                         *sgen_card_table_get_card_address (start) = 2;
 715                 }
 716                 start += CARD_SIZE_IN_BYTES;
 717         }
 718 }
 719
 720 #endif
 721
 722 static void
 723 sgen_card_tables_collect_stats (gboolean begin)
 724 {
 725 #ifdef CARDTABLE_STATS
 726         if (begin) {
 727                 memset (&major_stats, 0, sizeof (card_stats));
 728                 memset (&los_stats, 0, sizeof (card_stats));
 729                 cur_stats = &major_stats;
 730                 sgen_major_collector_iterate_live_block_ranges (count_marked_cards);
 731                 cur_stats = &los_stats;
 732                 sgen_los_iterate_live_block_ranges (count_marked_cards);
 733         } else {
 734                 cur_stats = &major_stats;
 735                 sgen_major_collector_iterate_live_block_ranges (count_remarked_cards);
 736                 cur_stats = &los_stats;
 737                 sgen_los_iterate_live_block_ranges (count_remarked_cards);
 738                 printf ("cards major (t %d m %d g %d r %d)  los (t %d m %d g %d r %d) major_scan %.2fms los_scan %.2fms\n",
 739                         major_stats.total, major_stats.marked, major_stats.gc_marked, major_stats.remarked,
 740                         los_stats.total, los_stats.marked, los_stats.gc_marked, los_stats.remarked,
 741                         last_major_scan_time / 10000.0f, last_los_scan_time / 10000.0f);
 742         }
 743 #endif
 744 }
 745
 746 void
 747 sgen_card_table_init (SgenRemeberedSet *remset)
 748 {
 749         sgen_cardtable = sgen_alloc_os_memory (CARD_COUNT_IN_BYTES, SGEN_ALLOC_INTERNAL | SGEN_ALLOC_ACTIVATE, "card table");
 750
 751 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 752         sgen_shadow_cardtable = sgen_alloc_os_memory (CARD_COUNT_IN_BYTES, SGEN_ALLOC_INTERNAL | SGEN_ALLOC_ACTIVATE, "shadow card table");
 753 #endif
 754
 755 #ifdef HEAVY_STATISTICS
 756         mono_counters_register ("marked cards", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &marked_cards);
 757         mono_counters_register ("scanned cards", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &scanned_cards);
 758         mono_counters_register ("remarked cards", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &remarked_cards);
 759
 760         mono_counters_register ("los marked cards", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &los_marked_cards);
 761         mono_counters_register ("los array cards scanned ", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &los_array_cards);
 762         mono_counters_register ("los array remsets", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &los_array_remsets);
 763         mono_counters_register ("cardtable scanned objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &scanned_objects);
 764         mono_counters_register ("cardtable large objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &large_objects);
 765         mono_counters_register ("cardtable bloby objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &bloby_objects);
 766 #endif
 767         mono_counters_register ("cardtable major scan time", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &major_card_scan_time);
 768         mono_counters_register ("cardtable los scan time", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &los_card_scan_time);
 769
 770
 771         remset->wbarrier_set_field = sgen_card_table_wbarrier_set_field;
 772         remset->wbarrier_set_arrayref = sgen_card_table_wbarrier_set_arrayref;
 773         remset->wbarrier_arrayref_copy = sgen_card_table_wbarrier_arrayref_copy;
 774         remset->wbarrier_value_copy = sgen_card_table_wbarrier_value_copy;
 775         remset->wbarrier_object_copy = sgen_card_table_wbarrier_object_copy;
 776         remset->wbarrier_generic_nostore = sgen_card_table_wbarrier_generic_nostore;
 777         remset->record_pointer = sgen_card_table_record_pointer;
 778
 779         remset->finish_scan_remsets = sgen_card_table_finish_scan_remsets;
 780
 781         remset->finish_minor_collection = sgen_card_table_finish_minor_collection;
 782         remset->prepare_for_major_collection = sgen_card_table_prepare_for_major_collection;
 783
 784         remset->find_address = sgen_card_table_find_address;
 785         remset->find_address_with_cards = sgen_card_table_find_address_with_cards;
 786
 787         need_mod_union = sgen_get_major_collector ()->is_concurrent;
 788 }
 789
 790 #endif /*HAVE_SGEN_GC*/