1 /* 2 * Copyright (c) 2001, 2014, 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 SparsePRTEntry* entry = get_entry(region_ind); 198 if (entry == NULL) { 199 return false; 200 } 201 // Otherwise... 202 entry->copy_cards(cards); 203 return true; 204 } 205 206 SparsePRTEntry* RSHashTable::get_entry(RegionIdx_t region_ind) const { 207 int ind = (int) (region_ind & capacity_mask()); 208 int cur_ind = _buckets[ind]; 209 SparsePRTEntry* cur; 210 while (cur_ind != NullEntry && 211 (cur = entry(cur_ind))->r_ind() != region_ind) { 212 cur_ind = cur->next_index(); 213 } 214 215 if (cur_ind == NullEntry) return NULL; 216 // Otherwise... 217 assert(cur->r_ind() == region_ind, "Postcondition of loop + test above."); 218 assert(cur->num_valid_cards() > 0, "Inv"); 219 return cur; 220 } 221 222 bool RSHashTable::delete_entry(RegionIdx_t region_ind) { 223 int ind = (int) (region_ind & capacity_mask()); 224 int* prev_loc = &_buckets[ind]; 225 int cur_ind = *prev_loc; 226 SparsePRTEntry* cur; 227 while (cur_ind != NullEntry && 228 (cur = entry(cur_ind))->r_ind() != region_ind) { 229 prev_loc = cur->next_index_addr(); 230 cur_ind = *prev_loc; 231 } 232 233 if (cur_ind == NullEntry) return false; 234 // Otherwise, splice out "cur". 235 *prev_loc = cur->next_index(); 236 _occupied_cards -= cur->num_valid_cards(); 237 free_entry(cur_ind); 238 _occupied_entries--; 239 return true; 240 } 241 242 SparsePRTEntry* 243 RSHashTable::entry_for_region_ind_create(RegionIdx_t region_ind) { 244 SparsePRTEntry* res = get_entry(region_ind); 245 if (res == NULL) { 246 int new_ind = alloc_entry(); 247 assert(0 <= new_ind && (size_t)new_ind < capacity(), "There should be room."); 248 res = entry(new_ind); 249 res->init(region_ind); 250 // Insert at front. 251 int ind = (int) (region_ind & capacity_mask()); 252 res->set_next_index(_buckets[ind]); 253 _buckets[ind] = new_ind; 254 _occupied_entries++; 255 } 256 return res; 257 } 258 259 int RSHashTable::alloc_entry() { 260 int res; 261 if (_free_list != NullEntry) { 262 res = _free_list; 263 _free_list = entry(res)->next_index(); 264 return res; 265 } else if ((size_t) _free_region+1 < capacity()) { 266 res = _free_region; 267 _free_region++; 268 return res; 269 } else { 270 return NullEntry; 271 } 272 } 273 274 void RSHashTable::free_entry(int fi) { 275 entry(fi)->set_next_index(_free_list); 276 _free_list = fi; 277 } 278 279 void RSHashTable::add_entry(SparsePRTEntry* e) { 280 assert(e->num_valid_cards() > 0, "Precondition."); 281 SparsePRTEntry* e2 = entry_for_region_ind_create(e->r_ind()); 282 e->copy_cards(e2); 283 _occupied_cards += e2->num_valid_cards(); 284 assert(e2->num_valid_cards() > 0, "Postcondition."); 285 } 286 287 CardIdx_t RSHashTableIter::find_first_card_in_list() { 288 CardIdx_t res; 289 while (_bl_ind != RSHashTable::NullEntry) { 290 res = _rsht->entry(_bl_ind)->card(0); 291 if (res != SparsePRTEntry::NullEntry) { 292 return res; 293 } else { 294 _bl_ind = _rsht->entry(_bl_ind)->next_index(); 295 } 296 } 297 // Otherwise, none found: 298 return SparsePRTEntry::NullEntry; 299 } 300 301 size_t RSHashTableIter::compute_card_ind(CardIdx_t ci) { 302 return (_rsht->entry(_bl_ind)->r_ind() * HeapRegion::CardsPerRegion) + ci; 303 } 304 305 bool RSHashTableIter::has_next(size_t& card_index) { 306 _card_ind++; 307 CardIdx_t ci; 308 if (_card_ind < SparsePRTEntry::cards_num() && 309 ((ci = _rsht->entry(_bl_ind)->card(_card_ind)) != 310 SparsePRTEntry::NullEntry)) { 311 card_index = compute_card_ind(ci); 312 return true; 313 } 314 // Otherwise, must find the next valid entry. 315 _card_ind = 0; 316 317 if (_bl_ind != RSHashTable::NullEntry) { 318 _bl_ind = _rsht->entry(_bl_ind)->next_index(); 319 ci = find_first_card_in_list(); 320 if (ci != SparsePRTEntry::NullEntry) { 321 card_index = compute_card_ind(ci); 322 return true; 323 } 324 } 325 // If we didn't return above, must go to the next non-null table index. 326 _tbl_ind++; 327 while ((size_t)_tbl_ind < _rsht->capacity()) { 328 _bl_ind = _rsht->_buckets[_tbl_ind]; 329 ci = find_first_card_in_list(); 330 if (ci != SparsePRTEntry::NullEntry) { 331 card_index = compute_card_ind(ci); 332 return true; 333 } 334 // Otherwise, try next entry. 335 _tbl_ind++; 336 } 337 // Otherwise, there were no entry. 338 return false; 339 } 340 341 bool RSHashTable::contains_card(RegionIdx_t region_index, CardIdx_t card_index) const { 342 SparsePRTEntry* e = get_entry(region_index); 343 return (e != NULL && e->contains_card(card_index)); 344 } 345 346 size_t RSHashTable::mem_size() const { 347 return sizeof(RSHashTable) + 348 capacity() * (SparsePRTEntry::size() + sizeof(int)); 349 } 350 351 // ---------------------------------------------------------------------- 352 353 SparsePRT* SparsePRT::_head_expanded_list = NULL; 354 355 void SparsePRT::add_to_expanded_list(SparsePRT* sprt) { 356 // We could expand multiple times in a pause -- only put on list once. 357 if (sprt->expanded()) return; 358 sprt->set_expanded(true); 359 SparsePRT* hd = _head_expanded_list; 360 while (true) { 361 sprt->_next_expanded = hd; 362 SparsePRT* res = 363 (SparsePRT*) 364 Atomic::cmpxchg_ptr(sprt, &_head_expanded_list, hd); 365 if (res == hd) return; 366 else hd = res; 367 } 368 } 369 370 371 SparsePRT* SparsePRT::get_from_expanded_list() { 372 SparsePRT* hd = _head_expanded_list; 373 while (hd != NULL) { 374 SparsePRT* next = hd->next_expanded(); 375 SparsePRT* res = 376 (SparsePRT*) 377 Atomic::cmpxchg_ptr(next, &_head_expanded_list, hd); 378 if (res == hd) { 379 hd->set_next_expanded(NULL); 380 return hd; 381 } else { 382 hd = res; 383 } 384 } 385 return NULL; 386 } 387 388 void SparsePRT::reset_for_cleanup_tasks() { 389 _head_expanded_list = NULL; 390 } 391 392 void SparsePRT::do_cleanup_work(SparsePRTCleanupTask* sprt_cleanup_task) { 393 if (should_be_on_expanded_list()) { 394 sprt_cleanup_task->add(this); 395 } 396 } 397 398 void SparsePRT::finish_cleanup_task(SparsePRTCleanupTask* sprt_cleanup_task) { 399 assert(ParGCRareEvent_lock->owned_by_self(), "pre-condition"); 400 SparsePRT* head = sprt_cleanup_task->head(); 401 SparsePRT* tail = sprt_cleanup_task->tail(); 402 if (head != NULL) { 403 assert(tail != NULL, "if head is not NULL, so should tail"); 404 405 tail->set_next_expanded(_head_expanded_list); 406 _head_expanded_list = head; 407 } else { 408 assert(tail == NULL, "if head is NULL, so should tail"); 409 } 410 } 411 412 bool SparsePRT::should_be_on_expanded_list() { 413 if (_expanded) { 414 assert(_cur != _next, "if _expanded is true, cur should be != _next"); 415 } else { 416 assert(_cur == _next, "if _expanded is false, cur should be == _next"); 417 } 418 return expanded(); 419 } 420 421 void SparsePRT::cleanup_all() { 422 // First clean up all expanded tables so they agree on next and cur. 423 SparsePRT* sprt = get_from_expanded_list(); 424 while (sprt != NULL) { 425 sprt->cleanup(); 426 sprt = get_from_expanded_list(); 427 } 428 } 429 430 431 SparsePRT::SparsePRT(HeapRegion* hr) : 432 _hr(hr), _expanded(false), _next_expanded(NULL) 433 { 434 _cur = new RSHashTable(InitialCapacity); 435 _next = _cur; 436 } 437 438 439 SparsePRT::~SparsePRT() { 440 assert(_next != NULL && _cur != NULL, "Inv"); 441 if (_cur != _next) { delete _cur; } 442 delete _next; 443 } 444 445 446 size_t SparsePRT::mem_size() const { 447 // We ignore "_cur" here, because it either = _next, or else it is 448 // on the deleted list. 449 return sizeof(SparsePRT) + _next->mem_size(); 450 } 451 452 bool SparsePRT::add_card(RegionIdx_t region_id, CardIdx_t card_index) { 453 #if SPARSE_PRT_VERBOSE 454 gclog_or_tty->print_cr(" Adding card %d from region %d to region %u sparse.", 455 card_index, region_id, _hr->hrs_index()); 456 #endif 457 if (_next->occupied_entries() * 2 > _next->capacity()) { 458 expand(); 459 } 460 return _next->add_card(region_id, card_index); 461 } 462 463 bool SparsePRT::get_cards(RegionIdx_t region_id, CardIdx_t* cards) { 464 return _next->get_cards(region_id, cards); 465 } 466 467 SparsePRTEntry* SparsePRT::get_entry(RegionIdx_t region_id) { 468 return _next->get_entry(region_id); 469 } 470 471 bool SparsePRT::delete_entry(RegionIdx_t region_id) { 472 return _next->delete_entry(region_id); 473 } 474 475 void SparsePRT::clear() { 476 // If they differ, _next is bigger then cur, so next has no chance of 477 // being the initial size. 478 if (_next != _cur) { 479 delete _next; 480 } 481 482 if (_cur->capacity() != InitialCapacity) { 483 delete _cur; 484 _cur = new RSHashTable(InitialCapacity); 485 } else { 486 _cur->clear(); 487 } 488 _next = _cur; 489 _expanded = false; 490 } 491 492 void SparsePRT::cleanup() { 493 // Make sure that the current and next tables agree. 494 if (_cur != _next) { 495 delete _cur; 496 } 497 _cur = _next; 498 set_expanded(false); 499 } 500 501 void SparsePRT::expand() { 502 RSHashTable* last = _next; 503 _next = new RSHashTable(last->capacity() * 2); 504 505 #if SPARSE_PRT_VERBOSE 506 gclog_or_tty->print_cr(" Expanded sparse table for %u to %d.", 507 _hr->hrs_index(), _next->capacity()); 508 #endif 509 for (size_t i = 0; i < last->capacity(); i++) { 510 SparsePRTEntry* e = last->entry((int)i); 511 if (e->valid_entry()) { 512 #if SPARSE_PRT_VERBOSE 513 gclog_or_tty->print_cr(" During expansion, transferred entry for %d.", 514 e->r_ind()); 515 #endif 516 _next->add_entry(e); 517 } 518 } 519 if (last != _cur) { 520 delete last; 521 } 522 add_to_expanded_list(this); 523 } 524 525 void SparsePRTCleanupTask::add(SparsePRT* sprt) { 526 assert(sprt->should_be_on_expanded_list(), "pre-condition"); 527 528 sprt->set_next_expanded(NULL); 529 if (_tail != NULL) { 530 _tail->set_next_expanded(sprt); 531 } else { 532 _head = sprt; 533 } 534 _tail = sprt; 535 }