1 /* 2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc_implementation/g1/heapRegion.hpp" 27 #include "gc_implementation/g1/heapRegionRemSet.hpp" 28 #include "gc_implementation/g1/sparsePRT.hpp" 29 #include "memory/allocation.inline.hpp" 30 #include "memory/cardTableModRefBS.hpp" 31 #include "memory/space.inline.hpp" 32 #include "runtime/mutexLocker.hpp" 33 34 #define SPARSE_PRT_VERBOSE 0 35 36 #define UNROLL_CARD_LOOPS 1 37 38 void SparsePRTEntry::init(RegionIdx_t region_ind) { 39 _region_ind = region_ind; 40 _next_index = NullEntry; 41 42 #if UNROLL_CARD_LOOPS 43 assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry"); 44 for (int i = 0; i < cards_num(); i += UnrollFactor) { 45 _cards[i] = NullEntry; 46 _cards[i + 1] = NullEntry; 47 _cards[i + 2] = NullEntry; 48 _cards[i + 3] = NullEntry; 49 } 50 #else 51 for (int i = 0; i < cards_num(); i++) 52 _cards[i] = NullEntry; 53 #endif 54 } 55 56 bool SparsePRTEntry::contains_card(CardIdx_t card_index) const { 57 #if UNROLL_CARD_LOOPS 58 assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry"); 59 for (int i = 0; i < cards_num(); i += UnrollFactor) { 60 if (_cards[i] == card_index || 61 _cards[i + 1] == card_index || 62 _cards[i + 2] == card_index || 63 _cards[i + 3] == card_index) return true; 64 } 65 #else 66 for (int i = 0; i < cards_num(); i++) { 67 if (_cards[i] == card_index) return true; 68 } 69 #endif 70 // Otherwise, we're full. 71 return false; 72 } 73 74 int SparsePRTEntry::num_valid_cards() const { 75 int sum = 0; 76 #if UNROLL_CARD_LOOPS 77 assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry"); 78 for (int i = 0; i < cards_num(); i += UnrollFactor) { 79 sum += (_cards[i] != NullEntry); 80 sum += (_cards[i + 1] != NullEntry); 81 sum += (_cards[i + 2] != NullEntry); 82 sum += (_cards[i + 3] != NullEntry); 83 } 84 #else 85 for (int i = 0; i < cards_num(); i++) { 86 sum += (_cards[i] != NullEntry); 87 } 88 #endif 89 // Otherwise, we're full. 90 return sum; 91 } 92 93 SparsePRTEntry::AddCardResult SparsePRTEntry::add_card(CardIdx_t card_index) { 94 #if UNROLL_CARD_LOOPS 95 assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry"); 96 CardIdx_t c; 97 for (int i = 0; i < cards_num(); i += UnrollFactor) { 98 c = _cards[i]; 99 if (c == card_index) return found; 100 if (c == NullEntry) { _cards[i] = card_index; return added; } 101 c = _cards[i + 1]; 102 if (c == card_index) return found; 103 if (c == NullEntry) { _cards[i + 1] = card_index; return added; } 104 c = _cards[i + 2]; 105 if (c == card_index) return found; 106 if (c == NullEntry) { _cards[i + 2] = card_index; return added; } 107 c = _cards[i + 3]; 108 if (c == card_index) return found; 109 if (c == NullEntry) { _cards[i + 3] = card_index; return added; } 110 } 111 #else 112 for (int i = 0; i < cards_num(); i++) { 113 CardIdx_t c = _cards[i]; 114 if (c == card_index) return found; 115 if (c == NullEntry) { _cards[i] = card_index; return added; } 116 } 117 #endif 118 // Otherwise, we're full. 119 return overflow; 120 } 121 122 void SparsePRTEntry::copy_cards(CardIdx_t* cards) const { 123 #if UNROLL_CARD_LOOPS 124 assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry"); 125 for (int i = 0; i < cards_num(); i += UnrollFactor) { 126 cards[i] = _cards[i]; 127 cards[i + 1] = _cards[i + 1]; 128 cards[i + 2] = _cards[i + 2]; 129 cards[i + 3] = _cards[i + 3]; 130 } 131 #else 132 for (int i = 0; i < cards_num(); i++) { 133 cards[i] = _cards[i]; 134 } 135 #endif 136 } 137 138 void SparsePRTEntry::copy_cards(SparsePRTEntry* e) const { 139 copy_cards(&e->_cards[0]); 140 } 141 142 // ---------------------------------------------------------------------- 143 144 RSHashTable::RSHashTable(size_t capacity) : 145 _capacity(capacity), _capacity_mask(capacity-1), 146 _occupied_entries(0), _occupied_cards(0), 147 _entries((SparsePRTEntry*)NEW_C_HEAP_ARRAY(char, SparsePRTEntry::size() * capacity, mtGC)), 148 _buckets(NEW_C_HEAP_ARRAY(int, capacity, mtGC)), 149 _free_list(NullEntry), _free_region(0) 150 { 151 clear(); 152 } 153 154 RSHashTable::~RSHashTable() { 155 if (_entries != NULL) { 156 FREE_C_HEAP_ARRAY(SparsePRTEntry, _entries, mtGC); 157 _entries = NULL; 158 } 159 if (_buckets != NULL) { 160 FREE_C_HEAP_ARRAY(int, _buckets, mtGC); 161 _buckets = NULL; 162 } 163 } 164 165 void RSHashTable::clear() { 166 _occupied_entries = 0; 167 _occupied_cards = 0; 168 guarantee(_entries != NULL, "INV"); 169 guarantee(_buckets != NULL, "INV"); 170 171 guarantee(_capacity <= ((size_t)1 << (sizeof(int)*BitsPerByte-1)) - 1, 172 "_capacity too large"); 173 174 // This will put -1 == NullEntry in the key field of all entries. 175 memset(_entries, NullEntry, _capacity * SparsePRTEntry::size()); 176 memset(_buckets, NullEntry, _capacity * sizeof(int)); 177 _free_list = NullEntry; 178 _free_region = 0; 179 } 180 181 bool RSHashTable::add_card(RegionIdx_t region_ind, CardIdx_t card_index) { 182 SparsePRTEntry* e = entry_for_region_ind_create(region_ind); 183 assert(e != NULL && e->r_ind() == region_ind, 184 "Postcondition of call above."); 185 SparsePRTEntry::AddCardResult res = e->add_card(card_index); 186 if (res == SparsePRTEntry::added) _occupied_cards++; 187 #if SPARSE_PRT_VERBOSE 188 gclog_or_tty->print_cr(" after add_card[%d]: valid-cards = %d.", 189 pointer_delta(e, _entries, SparsePRTEntry::size()), 190 e->num_valid_cards()); 191 #endif 192 assert(e->num_valid_cards() > 0, "Postcondition"); 193 return res != SparsePRTEntry::overflow; 194 } 195 196 bool RSHashTable::get_cards(RegionIdx_t region_ind, CardIdx_t* cards) { 197 int ind = (int) (region_ind & capacity_mask()); 198 int cur_ind = _buckets[ind]; 199 SparsePRTEntry* cur; 200 while (cur_ind != NullEntry && 201 (cur = entry(cur_ind))->r_ind() != region_ind) { 202 cur_ind = cur->next_index(); 203 } 204 205 if (cur_ind == NullEntry) return false; 206 // Otherwise... 207 assert(cur->r_ind() == region_ind, "Postcondition of loop + test above."); 208 assert(cur->num_valid_cards() > 0, "Inv"); 209 cur->copy_cards(cards); 210 return true; 211 } 212 213 SparsePRTEntry* RSHashTable::get_entry(RegionIdx_t region_ind) { 214 int ind = (int) (region_ind & capacity_mask()); 215 int cur_ind = _buckets[ind]; 216 SparsePRTEntry* cur; 217 while (cur_ind != NullEntry && 218 (cur = entry(cur_ind))->r_ind() != region_ind) { 219 cur_ind = cur->next_index(); 220 } 221 222 if (cur_ind == NullEntry) return NULL; 223 // Otherwise... 224 assert(cur->r_ind() == region_ind, "Postcondition of loop + test above."); 225 assert(cur->num_valid_cards() > 0, "Inv"); 226 return cur; 227 } 228 229 bool RSHashTable::delete_entry(RegionIdx_t region_ind) { 230 int ind = (int) (region_ind & capacity_mask()); 231 int* prev_loc = &_buckets[ind]; 232 int cur_ind = *prev_loc; 233 SparsePRTEntry* cur; 234 while (cur_ind != NullEntry && 235 (cur = entry(cur_ind))->r_ind() != region_ind) { 236 prev_loc = cur->next_index_addr(); 237 cur_ind = *prev_loc; 238 } 239 240 if (cur_ind == NullEntry) return false; 241 // Otherwise, splice out "cur". 242 *prev_loc = cur->next_index(); 243 _occupied_cards -= cur->num_valid_cards(); 244 free_entry(cur_ind); 245 _occupied_entries--; 246 return true; 247 } 248 249 SparsePRTEntry* 250 RSHashTable::entry_for_region_ind(RegionIdx_t region_ind) const { 251 assert(occupied_entries() < capacity(), "Precondition"); 252 int ind = (int) (region_ind & capacity_mask()); 253 int cur_ind = _buckets[ind]; 254 SparsePRTEntry* cur; 255 while (cur_ind != NullEntry && 256 (cur = entry(cur_ind))->r_ind() != region_ind) { 257 cur_ind = cur->next_index(); 258 } 259 260 if (cur_ind != NullEntry) { 261 assert(cur->r_ind() == region_ind, "Loop postcondition + test"); 262 return cur; 263 } else { 264 return NULL; 265 } 266 } 267 268 SparsePRTEntry* 269 RSHashTable::entry_for_region_ind_create(RegionIdx_t region_ind) { 270 SparsePRTEntry* res = entry_for_region_ind(region_ind); 271 if (res == NULL) { 272 int new_ind = alloc_entry(); 273 assert(0 <= new_ind && (size_t)new_ind < capacity(), "There should be room."); 274 res = entry(new_ind); 275 res->init(region_ind); 276 // Insert at front. 277 int ind = (int) (region_ind & capacity_mask()); 278 res->set_next_index(_buckets[ind]); 279 _buckets[ind] = new_ind; 280 _occupied_entries++; 281 } 282 return res; 283 } 284 285 int RSHashTable::alloc_entry() { 286 int res; 287 if (_free_list != NullEntry) { 288 res = _free_list; 289 _free_list = entry(res)->next_index(); 290 return res; 291 } else if ((size_t) _free_region+1 < capacity()) { 292 res = _free_region; 293 _free_region++; 294 return res; 295 } else { 296 return NullEntry; 297 } 298 } 299 300 void RSHashTable::free_entry(int fi) { 301 entry(fi)->set_next_index(_free_list); 302 _free_list = fi; 303 } 304 305 void RSHashTable::add_entry(SparsePRTEntry* e) { 306 assert(e->num_valid_cards() > 0, "Precondition."); 307 SparsePRTEntry* e2 = entry_for_region_ind_create(e->r_ind()); 308 e->copy_cards(e2); 309 _occupied_cards += e2->num_valid_cards(); 310 assert(e2->num_valid_cards() > 0, "Postcondition."); 311 } 312 313 CardIdx_t RSHashTableIter::find_first_card_in_list() { 314 CardIdx_t res; 315 while (_bl_ind != RSHashTable::NullEntry) { 316 res = _rsht->entry(_bl_ind)->card(0); 317 if (res != SparsePRTEntry::NullEntry) { 318 return res; 319 } else { 320 _bl_ind = _rsht->entry(_bl_ind)->next_index(); 321 } 322 } 323 // Otherwise, none found: 324 return SparsePRTEntry::NullEntry; 325 } 326 327 size_t RSHashTableIter::compute_card_ind(CardIdx_t ci) { 328 return (_rsht->entry(_bl_ind)->r_ind() * HeapRegion::CardsPerRegion) + ci; 329 } 330 331 bool RSHashTableIter::has_next(size_t& card_index) { 332 _card_ind++; 333 CardIdx_t ci; 334 if (_card_ind < SparsePRTEntry::cards_num() && 335 ((ci = _rsht->entry(_bl_ind)->card(_card_ind)) != 336 SparsePRTEntry::NullEntry)) { 337 card_index = compute_card_ind(ci); 338 return true; 339 } 340 // Otherwise, must find the next valid entry. 341 _card_ind = 0; 342 343 if (_bl_ind != RSHashTable::NullEntry) { 344 _bl_ind = _rsht->entry(_bl_ind)->next_index(); 345 ci = find_first_card_in_list(); 346 if (ci != SparsePRTEntry::NullEntry) { 347 card_index = compute_card_ind(ci); 348 return true; 349 } 350 } 351 // If we didn't return above, must go to the next non-null table index. 352 _tbl_ind++; 353 while ((size_t)_tbl_ind < _rsht->capacity()) { 354 _bl_ind = _rsht->_buckets[_tbl_ind]; 355 ci = find_first_card_in_list(); 356 if (ci != SparsePRTEntry::NullEntry) { 357 card_index = compute_card_ind(ci); 358 return true; 359 } 360 // Otherwise, try next entry. 361 _tbl_ind++; 362 } 363 // Otherwise, there were no entry. 364 return false; 365 } 366 367 bool RSHashTable::contains_card(RegionIdx_t region_index, CardIdx_t card_index) const { 368 SparsePRTEntry* e = entry_for_region_ind(region_index); 369 return (e != NULL && e->contains_card(card_index)); 370 } 371 372 size_t RSHashTable::mem_size() const { 373 return sizeof(this) + 374 capacity() * (SparsePRTEntry::size() + sizeof(int)); 375 } 376 377 // ---------------------------------------------------------------------- 378 379 SparsePRT* SparsePRT::_head_expanded_list = NULL; 380 381 void SparsePRT::add_to_expanded_list(SparsePRT* sprt) { 382 // We could expand multiple times in a pause -- only put on list once. 383 if (sprt->expanded()) return; 384 sprt->set_expanded(true); 385 SparsePRT* hd = _head_expanded_list; 386 while (true) { 387 sprt->_next_expanded = hd; 388 SparsePRT* res = 389 (SparsePRT*) 390 Atomic::cmpxchg_ptr(sprt, &_head_expanded_list, hd); 391 if (res == hd) return; 392 else hd = res; 393 } 394 } 395 396 397 SparsePRT* SparsePRT::get_from_expanded_list() { 398 SparsePRT* hd = _head_expanded_list; 399 while (hd != NULL) { 400 SparsePRT* next = hd->next_expanded(); 401 SparsePRT* res = 402 (SparsePRT*) 403 Atomic::cmpxchg_ptr(next, &_head_expanded_list, hd); 404 if (res == hd) { 405 hd->set_next_expanded(NULL); 406 return hd; 407 } else { 408 hd = res; 409 } 410 } 411 return NULL; 412 } 413 414 void SparsePRT::reset_for_cleanup_tasks() { 415 _head_expanded_list = NULL; 416 } 417 418 void SparsePRT::do_cleanup_work(SparsePRTCleanupTask* sprt_cleanup_task) { 419 if (should_be_on_expanded_list()) { 420 sprt_cleanup_task->add(this); 421 } 422 } 423 424 void SparsePRT::finish_cleanup_task(SparsePRTCleanupTask* sprt_cleanup_task) { 425 assert(ParGCRareEvent_lock->owned_by_self(), "pre-condition"); 426 SparsePRT* head = sprt_cleanup_task->head(); 427 SparsePRT* tail = sprt_cleanup_task->tail(); 428 if (head != NULL) { 429 assert(tail != NULL, "if head is not NULL, so should tail"); 430 431 tail->set_next_expanded(_head_expanded_list); 432 _head_expanded_list = head; 433 } else { 434 assert(tail == NULL, "if head is NULL, so should tail"); 435 } 436 } 437 438 bool SparsePRT::should_be_on_expanded_list() { 439 if (_expanded) { 440 assert(_cur != _next, "if _expanded is true, cur should be != _next"); 441 } else { 442 assert(_cur == _next, "if _expanded is false, cur should be == _next"); 443 } 444 return expanded(); 445 } 446 447 void SparsePRT::cleanup_all() { 448 // First clean up all expanded tables so they agree on next and cur. 449 SparsePRT* sprt = get_from_expanded_list(); 450 while (sprt != NULL) { 451 sprt->cleanup(); 452 sprt = get_from_expanded_list(); 453 } 454 } 455 456 457 SparsePRT::SparsePRT(HeapRegion* hr) : 458 _hr(hr), _expanded(false), _next_expanded(NULL) 459 { 460 _cur = new RSHashTable(InitialCapacity); 461 _next = _cur; 462 } 463 464 465 SparsePRT::~SparsePRT() { 466 assert(_next != NULL && _cur != NULL, "Inv"); 467 if (_cur != _next) { delete _cur; } 468 delete _next; 469 } 470 471 472 size_t SparsePRT::mem_size() const { 473 // We ignore "_cur" here, because it either = _next, or else it is 474 // on the deleted list. 475 return sizeof(this) + _next->mem_size(); 476 } 477 478 bool SparsePRT::add_card(RegionIdx_t region_id, CardIdx_t card_index) { 479 #if SPARSE_PRT_VERBOSE 480 gclog_or_tty->print_cr(" Adding card %d from region %d to region %u sparse.", 481 card_index, region_id, _hr->hrs_index()); 482 #endif 483 if (_next->occupied_entries() * 2 > _next->capacity()) { 484 expand(); 485 } 486 return _next->add_card(region_id, card_index); 487 } 488 489 bool SparsePRT::get_cards(RegionIdx_t region_id, CardIdx_t* cards) { 490 return _next->get_cards(region_id, cards); 491 } 492 493 SparsePRTEntry* SparsePRT::get_entry(RegionIdx_t region_id) { 494 return _next->get_entry(region_id); 495 } 496 497 bool SparsePRT::delete_entry(RegionIdx_t region_id) { 498 return _next->delete_entry(region_id); 499 } 500 501 void SparsePRT::clear() { 502 // If they differ, _next is bigger then cur, so next has no chance of 503 // being the initial size. 504 if (_next != _cur) { 505 delete _next; 506 } 507 508 if (_cur->capacity() != InitialCapacity) { 509 delete _cur; 510 _cur = new RSHashTable(InitialCapacity); 511 } else { 512 _cur->clear(); 513 } 514 _next = _cur; 515 _expanded = false; 516 } 517 518 void SparsePRT::cleanup() { 519 // Make sure that the current and next tables agree. 520 if (_cur != _next) { 521 delete _cur; 522 } 523 _cur = _next; 524 set_expanded(false); 525 } 526 527 void SparsePRT::expand() { 528 RSHashTable* last = _next; 529 _next = new RSHashTable(last->capacity() * 2); 530 531 #if SPARSE_PRT_VERBOSE 532 gclog_or_tty->print_cr(" Expanded sparse table for %u to %d.", 533 _hr->hrs_index(), _next->capacity()); 534 #endif 535 for (size_t i = 0; i < last->capacity(); i++) { 536 SparsePRTEntry* e = last->entry((int)i); 537 if (e->valid_entry()) { 538 #if SPARSE_PRT_VERBOSE 539 gclog_or_tty->print_cr(" During expansion, transferred entry for %d.", 540 e->r_ind()); 541 #endif 542 _next->add_entry(e); 543 } 544 } 545 if (last != _cur) { 546 delete last; 547 } 548 add_to_expanded_list(this); 549 } 550 551 void SparsePRTCleanupTask::add(SparsePRT* sprt) { 552 assert(sprt->should_be_on_expanded_list(), "pre-condition"); 553 554 sprt->set_next_expanded(NULL); 555 if (_tail != NULL) { 556 _tail->set_next_expanded(sprt); 557 } else { 558 _head = sprt; 559 } 560 _tail = sprt; 561 }