1 /* 2 * Copyright (c) 2001, 2011, 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/concurrentG1Refine.hpp" 27 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp" 28 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" 29 #include "gc_implementation/g1/heapRegionRemSet.hpp" 30 #include "gc_implementation/g1/heapRegionSeq.inline.hpp" 31 #include "memory/allocation.hpp" 32 #include "memory/space.inline.hpp" 33 #include "utilities/bitMap.inline.hpp" 34 #include "utilities/globalDefinitions.hpp" 35 36 #define HRRS_VERBOSE 0 37 38 #define PRT_COUNT_OCCUPIED 1 39 40 // OtherRegionsTable 41 42 class PerRegionTable: public CHeapObj { 43 friend class OtherRegionsTable; 44 friend class HeapRegionRemSetIterator; 45 46 HeapRegion* _hr; 47 BitMap _bm; 48 #if PRT_COUNT_OCCUPIED 49 jint _occupied; 50 #endif 51 PerRegionTable* _next_free; 52 53 PerRegionTable* next_free() { return _next_free; } 54 void set_next_free(PerRegionTable* prt) { _next_free = prt; } 55 56 57 static PerRegionTable* _free_list; 58 59 #ifdef _MSC_VER 60 // For some reason even though the classes are marked as friend they are unable 61 // to access CardsPerRegion when private/protected. Only the windows c++ compiler 62 // says this Sun CC and linux gcc don't have a problem with access when private 63 64 public: 65 66 #endif // _MSC_VER 67 68 protected: 69 // We need access in order to union things into the base table. 70 BitMap* bm() { return &_bm; } 71 72 #if PRT_COUNT_OCCUPIED 73 void recount_occupied() { 74 _occupied = (jint) bm()->count_one_bits(); 75 } 76 #endif 77 78 PerRegionTable(HeapRegion* hr) : 79 _hr(hr), 80 #if PRT_COUNT_OCCUPIED 81 _occupied(0), 82 #endif 83 _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */) 84 {} 85 86 static void free(PerRegionTable* prt) { 87 while (true) { 88 PerRegionTable* fl = _free_list; 89 prt->set_next_free(fl); 90 PerRegionTable* res = 91 (PerRegionTable*) 92 Atomic::cmpxchg_ptr(prt, &_free_list, fl); 93 if (res == fl) return; 94 } 95 ShouldNotReachHere(); 96 } 97 98 static PerRegionTable* alloc(HeapRegion* hr) { 99 PerRegionTable* fl = _free_list; 100 while (fl != NULL) { 101 PerRegionTable* nxt = fl->next_free(); 102 PerRegionTable* res = 103 (PerRegionTable*) 104 Atomic::cmpxchg_ptr(nxt, &_free_list, fl); 105 if (res == fl) { 106 fl->init(hr); 107 return fl; 108 } else { 109 fl = _free_list; 110 } 111 } 112 assert(fl == NULL, "Loop condition."); 113 return new PerRegionTable(hr); 114 } 115 116 void add_card_work(CardIdx_t from_card, bool par) { 117 if (!_bm.at(from_card)) { 118 if (par) { 119 if (_bm.par_at_put(from_card, 1)) { 120 #if PRT_COUNT_OCCUPIED 121 Atomic::inc(&_occupied); 122 #endif 123 } 124 } else { 125 _bm.at_put(from_card, 1); 126 #if PRT_COUNT_OCCUPIED 127 _occupied++; 128 #endif 129 } 130 } 131 } 132 133 void add_reference_work(OopOrNarrowOopStar from, bool par) { 134 // Must make this robust in case "from" is not in "_hr", because of 135 // concurrency. 136 137 #if HRRS_VERBOSE 138 gclog_or_tty->print_cr(" PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").", 139 from, *from); 140 #endif 141 142 HeapRegion* loc_hr = hr(); 143 // If the test below fails, then this table was reused concurrently 144 // with this operation. This is OK, since the old table was coarsened, 145 // and adding a bit to the new table is never incorrect. 146 if (loc_hr->is_in_reserved(from)) { 147 size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom()); 148 CardIdx_t from_card = (CardIdx_t) 149 hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize); 150 151 assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion, 152 "Must be in range."); 153 add_card_work(from_card, par); 154 } 155 } 156 157 public: 158 159 HeapRegion* hr() const { return _hr; } 160 161 #if PRT_COUNT_OCCUPIED 162 jint occupied() const { 163 // Overkill, but if we ever need it... 164 // guarantee(_occupied == _bm.count_one_bits(), "Check"); 165 return _occupied; 166 } 167 #else 168 jint occupied() const { 169 return _bm.count_one_bits(); 170 } 171 #endif 172 173 void init(HeapRegion* hr) { 174 _hr = hr; 175 #if PRT_COUNT_OCCUPIED 176 _occupied = 0; 177 #endif 178 _bm.clear(); 179 } 180 181 void add_reference(OopOrNarrowOopStar from) { 182 add_reference_work(from, /*parallel*/ true); 183 } 184 185 void seq_add_reference(OopOrNarrowOopStar from) { 186 add_reference_work(from, /*parallel*/ false); 187 } 188 189 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) { 190 HeapWord* hr_bot = hr()->bottom(); 191 size_t hr_first_card_index = ctbs->index_for(hr_bot); 192 bm()->set_intersection_at_offset(*card_bm, hr_first_card_index); 193 #if PRT_COUNT_OCCUPIED 194 recount_occupied(); 195 #endif 196 } 197 198 void add_card(CardIdx_t from_card_index) { 199 add_card_work(from_card_index, /*parallel*/ true); 200 } 201 202 void seq_add_card(CardIdx_t from_card_index) { 203 add_card_work(from_card_index, /*parallel*/ false); 204 } 205 206 // (Destructively) union the bitmap of the current table into the given 207 // bitmap (which is assumed to be of the same size.) 208 void union_bitmap_into(BitMap* bm) { 209 bm->set_union(_bm); 210 } 211 212 // Mem size in bytes. 213 size_t mem_size() const { 214 return sizeof(this) + _bm.size_in_words() * HeapWordSize; 215 } 216 217 static size_t fl_mem_size() { 218 PerRegionTable* cur = _free_list; 219 size_t res = 0; 220 while (cur != NULL) { 221 res += sizeof(PerRegionTable); 222 cur = cur->next_free(); 223 } 224 return res; 225 } 226 227 // Requires "from" to be in "hr()". 228 bool contains_reference(OopOrNarrowOopStar from) const { 229 assert(hr()->is_in_reserved(from), "Precondition."); 230 size_t card_ind = pointer_delta(from, hr()->bottom(), 231 CardTableModRefBS::card_size); 232 return _bm.at(card_ind); 233 } 234 }; 235 236 PerRegionTable* PerRegionTable::_free_list = NULL; 237 238 239 #define COUNT_PAR_EXPANDS 0 240 241 #if COUNT_PAR_EXPANDS 242 static jint n_par_expands = 0; 243 static jint n_par_contracts = 0; 244 static jint par_expand_list_len = 0; 245 static jint max_par_expand_list_len = 0; 246 247 static void print_par_expand() { 248 Atomic::inc(&n_par_expands); 249 Atomic::inc(&par_expand_list_len); 250 if (par_expand_list_len > max_par_expand_list_len) { 251 max_par_expand_list_len = par_expand_list_len; 252 } 253 if ((n_par_expands % 10) == 0) { 254 gclog_or_tty->print_cr("\n\n%d par expands: %d contracts, " 255 "len = %d, max_len = %d\n.", 256 n_par_expands, n_par_contracts, par_expand_list_len, 257 max_par_expand_list_len); 258 } 259 } 260 #endif 261 262 class PosParPRT: public PerRegionTable { 263 PerRegionTable** _par_tables; 264 265 enum SomePrivateConstants { 266 ReserveParTableExpansion = 1 267 }; 268 269 void par_contract() { 270 assert(_par_tables != NULL, "Precondition."); 271 int n = HeapRegionRemSet::num_par_rem_sets()-1; 272 for (int i = 0; i < n; i++) { 273 _par_tables[i]->union_bitmap_into(bm()); 274 PerRegionTable::free(_par_tables[i]); 275 _par_tables[i] = NULL; 276 } 277 #if PRT_COUNT_OCCUPIED 278 // We must recount the "occupied." 279 recount_occupied(); 280 #endif 281 FREE_C_HEAP_ARRAY(PerRegionTable*, _par_tables); 282 _par_tables = NULL; 283 #if COUNT_PAR_EXPANDS 284 Atomic::inc(&n_par_contracts); 285 Atomic::dec(&par_expand_list_len); 286 #endif 287 } 288 289 static PerRegionTable** _par_table_fl; 290 291 PosParPRT* _next; 292 293 static PosParPRT* _free_list; 294 295 PerRegionTable** par_tables() const { 296 assert(uintptr_t(NULL) == 0, "Assumption."); 297 if (uintptr_t(_par_tables) <= ReserveParTableExpansion) 298 return NULL; 299 else 300 return _par_tables; 301 } 302 303 PosParPRT* _next_par_expanded; 304 PosParPRT* next_par_expanded() { return _next_par_expanded; } 305 void set_next_par_expanded(PosParPRT* ppprt) { _next_par_expanded = ppprt; } 306 static PosParPRT* _par_expanded_list; 307 308 public: 309 310 PosParPRT(HeapRegion* hr) : PerRegionTable(hr), _par_tables(NULL) {} 311 312 jint occupied() const { 313 jint res = PerRegionTable::occupied(); 314 if (par_tables() != NULL) { 315 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) { 316 res += par_tables()[i]->occupied(); 317 } 318 } 319 return res; 320 } 321 322 void init(HeapRegion* hr) { 323 PerRegionTable::init(hr); 324 _next = NULL; 325 if (par_tables() != NULL) { 326 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) { 327 par_tables()[i]->init(hr); 328 } 329 } 330 } 331 332 static void free(PosParPRT* prt) { 333 while (true) { 334 PosParPRT* fl = _free_list; 335 prt->set_next(fl); 336 PosParPRT* res = 337 (PosParPRT*) 338 Atomic::cmpxchg_ptr(prt, &_free_list, fl); 339 if (res == fl) return; 340 } 341 ShouldNotReachHere(); 342 } 343 344 static PosParPRT* alloc(HeapRegion* hr) { 345 PosParPRT* fl = _free_list; 346 while (fl != NULL) { 347 PosParPRT* nxt = fl->next(); 348 PosParPRT* res = 349 (PosParPRT*) 350 Atomic::cmpxchg_ptr(nxt, &_free_list, fl); 351 if (res == fl) { 352 fl->init(hr); 353 return fl; 354 } else { 355 fl = _free_list; 356 } 357 } 358 assert(fl == NULL, "Loop condition."); 359 return new PosParPRT(hr); 360 } 361 362 PosParPRT* next() const { return _next; } 363 void set_next(PosParPRT* nxt) { _next = nxt; } 364 PosParPRT** next_addr() { return &_next; } 365 366 bool should_expand(int tid) { 367 // Given that we now defer RSet updates for after a GC we don't 368 // really need to expand the tables any more. This code should be 369 // cleaned up in the future (see CR 6921087). 370 return false; 371 } 372 373 void par_expand() { 374 int n = HeapRegionRemSet::num_par_rem_sets()-1; 375 if (n <= 0) return; 376 if (_par_tables == NULL) { 377 PerRegionTable* res = 378 (PerRegionTable*) 379 Atomic::cmpxchg_ptr((PerRegionTable*)ReserveParTableExpansion, 380 &_par_tables, NULL); 381 if (res != NULL) return; 382 // Otherwise, we reserved the right to do the expansion. 383 384 PerRegionTable** ptables = NEW_C_HEAP_ARRAY(PerRegionTable*, n); 385 for (int i = 0; i < n; i++) { 386 PerRegionTable* ptable = PerRegionTable::alloc(hr()); 387 ptables[i] = ptable; 388 } 389 // Here we do not need an atomic. 390 _par_tables = ptables; 391 #if COUNT_PAR_EXPANDS 392 print_par_expand(); 393 #endif 394 // We must put this table on the expanded list. 395 PosParPRT* exp_head = _par_expanded_list; 396 while (true) { 397 set_next_par_expanded(exp_head); 398 PosParPRT* res = 399 (PosParPRT*) 400 Atomic::cmpxchg_ptr(this, &_par_expanded_list, exp_head); 401 if (res == exp_head) return; 402 // Otherwise. 403 exp_head = res; 404 } 405 ShouldNotReachHere(); 406 } 407 } 408 409 void add_reference(OopOrNarrowOopStar from, int tid) { 410 // Expand if necessary. 411 PerRegionTable** pt = par_tables(); 412 if (pt != NULL) { 413 // We always have to assume that mods to table 0 are in parallel, 414 // because of the claiming scheme in parallel expansion. A thread 415 // with tid != 0 that finds the table to be NULL, but doesn't succeed 416 // in claiming the right of expanding it, will end up in the else 417 // clause of the above if test. That thread could be delayed, and a 418 // thread 0 add reference could see the table expanded, and come 419 // here. Both threads would be adding in parallel. But we get to 420 // not use atomics for tids > 0. 421 if (tid == 0) { 422 PerRegionTable::add_reference(from); 423 } else { 424 pt[tid-1]->seq_add_reference(from); 425 } 426 } else { 427 // Not expanded -- add to the base table. 428 PerRegionTable::add_reference(from); 429 } 430 } 431 432 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) { 433 assert(_par_tables == NULL, "Precondition"); 434 PerRegionTable::scrub(ctbs, card_bm); 435 } 436 437 size_t mem_size() const { 438 size_t res = 439 PerRegionTable::mem_size() + sizeof(this) - sizeof(PerRegionTable); 440 if (_par_tables != NULL) { 441 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) { 442 res += _par_tables[i]->mem_size(); 443 } 444 } 445 return res; 446 } 447 448 static size_t fl_mem_size() { 449 PosParPRT* cur = _free_list; 450 size_t res = 0; 451 while (cur != NULL) { 452 res += sizeof(PosParPRT); 453 cur = cur->next(); 454 } 455 return res; 456 } 457 458 bool contains_reference(OopOrNarrowOopStar from) const { 459 if (PerRegionTable::contains_reference(from)) return true; 460 if (_par_tables != NULL) { 461 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) { 462 if (_par_tables[i]->contains_reference(from)) return true; 463 } 464 } 465 return false; 466 } 467 468 static void par_contract_all(); 469 }; 470 471 void PosParPRT::par_contract_all() { 472 PosParPRT* hd = _par_expanded_list; 473 while (hd != NULL) { 474 PosParPRT* nxt = hd->next_par_expanded(); 475 PosParPRT* res = 476 (PosParPRT*) 477 Atomic::cmpxchg_ptr(nxt, &_par_expanded_list, hd); 478 if (res == hd) { 479 // We claimed the right to contract this table. 480 hd->set_next_par_expanded(NULL); 481 hd->par_contract(); 482 hd = _par_expanded_list; 483 } else { 484 hd = res; 485 } 486 } 487 } 488 489 PosParPRT* PosParPRT::_free_list = NULL; 490 PosParPRT* PosParPRT::_par_expanded_list = NULL; 491 492 jint OtherRegionsTable::_cache_probes = 0; 493 jint OtherRegionsTable::_cache_hits = 0; 494 495 size_t OtherRegionsTable::_max_fine_entries = 0; 496 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0; 497 #if SAMPLE_FOR_EVICTION 498 size_t OtherRegionsTable::_fine_eviction_stride = 0; 499 size_t OtherRegionsTable::_fine_eviction_sample_size = 0; 500 #endif 501 502 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr) : 503 _g1h(G1CollectedHeap::heap()), 504 _m(Mutex::leaf, "An OtherRegionsTable lock", true), 505 _hr(hr), 506 _coarse_map(G1CollectedHeap::heap()->max_regions(), 507 false /* in-resource-area */), 508 _fine_grain_regions(NULL), 509 _n_fine_entries(0), _n_coarse_entries(0), 510 #if SAMPLE_FOR_EVICTION 511 _fine_eviction_start(0), 512 #endif 513 _sparse_table(hr) 514 { 515 typedef PosParPRT* PosParPRTPtr; 516 if (_max_fine_entries == 0) { 517 assert(_mod_max_fine_entries_mask == 0, "Both or none."); 518 size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries); 519 _max_fine_entries = (size_t)(1 << max_entries_log); 520 _mod_max_fine_entries_mask = _max_fine_entries - 1; 521 #if SAMPLE_FOR_EVICTION 522 assert(_fine_eviction_sample_size == 0 523 && _fine_eviction_stride == 0, "All init at same time."); 524 _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log); 525 _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size; 526 #endif 527 } 528 _fine_grain_regions = new PosParPRTPtr[_max_fine_entries]; 529 if (_fine_grain_regions == NULL) 530 vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, 531 "Failed to allocate _fine_grain_entries."); 532 for (size_t i = 0; i < _max_fine_entries; i++) { 533 _fine_grain_regions[i] = NULL; 534 } 535 } 536 537 int** OtherRegionsTable::_from_card_cache = NULL; 538 size_t OtherRegionsTable::_from_card_cache_max_regions = 0; 539 size_t OtherRegionsTable::_from_card_cache_mem_size = 0; 540 541 void OtherRegionsTable::init_from_card_cache(size_t max_regions) { 542 _from_card_cache_max_regions = max_regions; 543 544 int n_par_rs = HeapRegionRemSet::num_par_rem_sets(); 545 _from_card_cache = NEW_C_HEAP_ARRAY(int*, n_par_rs); 546 for (int i = 0; i < n_par_rs; i++) { 547 _from_card_cache[i] = NEW_C_HEAP_ARRAY(int, max_regions); 548 for (size_t j = 0; j < max_regions; j++) { 549 _from_card_cache[i][j] = -1; // An invalid value. 550 } 551 } 552 _from_card_cache_mem_size = n_par_rs * max_regions * sizeof(int); 553 } 554 555 void OtherRegionsTable::shrink_from_card_cache(size_t new_n_regs) { 556 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 557 assert(new_n_regs <= _from_card_cache_max_regions, "Must be within max."); 558 for (size_t j = new_n_regs; j < _from_card_cache_max_regions; j++) { 559 _from_card_cache[i][j] = -1; // An invalid value. 560 } 561 } 562 } 563 564 #ifndef PRODUCT 565 void OtherRegionsTable::print_from_card_cache() { 566 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 567 for (size_t j = 0; j < _from_card_cache_max_regions; j++) { 568 gclog_or_tty->print_cr("_from_card_cache[%d][%d] = %d.", 569 i, j, _from_card_cache[i][j]); 570 } 571 } 572 } 573 #endif 574 575 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, int tid) { 576 size_t cur_hrs_ind = hr()->hrs_index(); 577 578 #if HRRS_VERBOSE 579 gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").", 580 from, 581 UseCompressedOops 582 ? oopDesc::load_decode_heap_oop((narrowOop*)from) 583 : oopDesc::load_decode_heap_oop((oop*)from)); 584 #endif 585 586 int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift); 587 588 #if HRRS_VERBOSE 589 gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)", 590 hr()->bottom(), from_card, 591 _from_card_cache[tid][cur_hrs_ind]); 592 #endif 593 594 #define COUNT_CACHE 0 595 #if COUNT_CACHE 596 jint p = Atomic::add(1, &_cache_probes); 597 if ((p % 10000) == 0) { 598 jint hits = _cache_hits; 599 gclog_or_tty->print_cr("%d/%d = %5.2f%% RS cache hits.", 600 _cache_hits, p, 100.0* (float)hits/(float)p); 601 } 602 #endif 603 if (from_card == _from_card_cache[tid][cur_hrs_ind]) { 604 #if HRRS_VERBOSE 605 gclog_or_tty->print_cr(" from-card cache hit."); 606 #endif 607 #if COUNT_CACHE 608 Atomic::inc(&_cache_hits); 609 #endif 610 assert(contains_reference(from), "We just added it!"); 611 return; 612 } else { 613 _from_card_cache[tid][cur_hrs_ind] = from_card; 614 } 615 616 // Note that this may be a continued H region. 617 HeapRegion* from_hr = _g1h->heap_region_containing_raw(from); 618 RegionIdx_t from_hrs_ind = (RegionIdx_t) from_hr->hrs_index(); 619 620 // If the region is already coarsened, return. 621 if (_coarse_map.at(from_hrs_ind)) { 622 #if HRRS_VERBOSE 623 gclog_or_tty->print_cr(" coarse map hit."); 624 #endif 625 assert(contains_reference(from), "We just added it!"); 626 return; 627 } 628 629 // Otherwise find a per-region table to add it to. 630 size_t ind = from_hrs_ind & _mod_max_fine_entries_mask; 631 PosParPRT* prt = find_region_table(ind, from_hr); 632 if (prt == NULL) { 633 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 634 // Confirm that it's really not there... 635 prt = find_region_table(ind, from_hr); 636 if (prt == NULL) { 637 638 uintptr_t from_hr_bot_card_index = 639 uintptr_t(from_hr->bottom()) 640 >> CardTableModRefBS::card_shift; 641 CardIdx_t card_index = from_card - from_hr_bot_card_index; 642 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion, 643 "Must be in range."); 644 if (G1HRRSUseSparseTable && 645 _sparse_table.add_card(from_hrs_ind, card_index)) { 646 if (G1RecordHRRSOops) { 647 HeapRegionRemSet::record(hr(), from); 648 #if HRRS_VERBOSE 649 gclog_or_tty->print(" Added card " PTR_FORMAT " to region " 650 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n", 651 align_size_down(uintptr_t(from), 652 CardTableModRefBS::card_size), 653 hr()->bottom(), from); 654 #endif 655 } 656 #if HRRS_VERBOSE 657 gclog_or_tty->print_cr(" added card to sparse table."); 658 #endif 659 assert(contains_reference_locked(from), "We just added it!"); 660 return; 661 } else { 662 #if HRRS_VERBOSE 663 gclog_or_tty->print_cr(" [tid %d] sparse table entry " 664 "overflow(f: %d, t: %d)", 665 tid, from_hrs_ind, cur_hrs_ind); 666 #endif 667 } 668 669 if (_n_fine_entries == _max_fine_entries) { 670 prt = delete_region_table(); 671 } else { 672 prt = PosParPRT::alloc(from_hr); 673 } 674 prt->init(from_hr); 675 676 PosParPRT* first_prt = _fine_grain_regions[ind]; 677 prt->set_next(first_prt); // XXX Maybe move to init? 678 _fine_grain_regions[ind] = prt; 679 _n_fine_entries++; 680 681 if (G1HRRSUseSparseTable) { 682 // Transfer from sparse to fine-grain. 683 SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrs_ind); 684 assert(sprt_entry != NULL, "There should have been an entry"); 685 for (int i = 0; i < SparsePRTEntry::cards_num(); i++) { 686 CardIdx_t c = sprt_entry->card(i); 687 if (c != SparsePRTEntry::NullEntry) { 688 prt->add_card(c); 689 } 690 } 691 // Now we can delete the sparse entry. 692 bool res = _sparse_table.delete_entry(from_hrs_ind); 693 assert(res, "It should have been there."); 694 } 695 } 696 assert(prt != NULL && prt->hr() == from_hr, "consequence"); 697 } 698 // Note that we can't assert "prt->hr() == from_hr", because of the 699 // possibility of concurrent reuse. But see head comment of 700 // OtherRegionsTable for why this is OK. 701 assert(prt != NULL, "Inv"); 702 703 if (prt->should_expand(tid)) { 704 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 705 HeapRegion* prt_hr = prt->hr(); 706 if (prt_hr == from_hr) { 707 // Make sure the table still corresponds to the same region 708 prt->par_expand(); 709 prt->add_reference(from, tid); 710 } 711 // else: The table has been concurrently coarsened, evicted, and 712 // the table data structure re-used for another table. So, we 713 // don't need to add the reference any more given that the table 714 // has been coarsened and the whole region will be scanned anyway. 715 } else { 716 prt->add_reference(from, tid); 717 } 718 if (G1RecordHRRSOops) { 719 HeapRegionRemSet::record(hr(), from); 720 #if HRRS_VERBOSE 721 gclog_or_tty->print("Added card " PTR_FORMAT " to region " 722 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n", 723 align_size_down(uintptr_t(from), 724 CardTableModRefBS::card_size), 725 hr()->bottom(), from); 726 #endif 727 } 728 assert(contains_reference(from), "We just added it!"); 729 } 730 731 PosParPRT* 732 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const { 733 assert(0 <= ind && ind < _max_fine_entries, "Preconditions."); 734 PosParPRT* prt = _fine_grain_regions[ind]; 735 while (prt != NULL && prt->hr() != hr) { 736 prt = prt->next(); 737 } 738 // Loop postcondition is the method postcondition. 739 return prt; 740 } 741 742 743 #define DRT_CENSUS 0 744 745 #if DRT_CENSUS 746 static const int HistoSize = 6; 747 static int global_histo[HistoSize] = { 0, 0, 0, 0, 0, 0 }; 748 static int coarsenings = 0; 749 static int occ_sum = 0; 750 #endif 751 752 jint OtherRegionsTable::_n_coarsenings = 0; 753 754 PosParPRT* OtherRegionsTable::delete_region_table() { 755 #if DRT_CENSUS 756 int histo[HistoSize] = { 0, 0, 0, 0, 0, 0 }; 757 const int histo_limits[] = { 1, 4, 16, 64, 256, 2048 }; 758 #endif 759 760 assert(_m.owned_by_self(), "Precondition"); 761 assert(_n_fine_entries == _max_fine_entries, "Precondition"); 762 PosParPRT* max = NULL; 763 jint max_occ = 0; 764 PosParPRT** max_prev; 765 size_t max_ind; 766 767 #if SAMPLE_FOR_EVICTION 768 size_t i = _fine_eviction_start; 769 for (size_t k = 0; k < _fine_eviction_sample_size; k++) { 770 size_t ii = i; 771 // Make sure we get a non-NULL sample. 772 while (_fine_grain_regions[ii] == NULL) { 773 ii++; 774 if (ii == _max_fine_entries) ii = 0; 775 guarantee(ii != i, "We must find one."); 776 } 777 PosParPRT** prev = &_fine_grain_regions[ii]; 778 PosParPRT* cur = *prev; 779 while (cur != NULL) { 780 jint cur_occ = cur->occupied(); 781 if (max == NULL || cur_occ > max_occ) { 782 max = cur; 783 max_prev = prev; 784 max_ind = i; 785 max_occ = cur_occ; 786 } 787 prev = cur->next_addr(); 788 cur = cur->next(); 789 } 790 i = i + _fine_eviction_stride; 791 if (i >= _n_fine_entries) i = i - _n_fine_entries; 792 } 793 _fine_eviction_start++; 794 if (_fine_eviction_start >= _n_fine_entries) 795 _fine_eviction_start -= _n_fine_entries; 796 #else 797 for (int i = 0; i < _max_fine_entries; i++) { 798 PosParPRT** prev = &_fine_grain_regions[i]; 799 PosParPRT* cur = *prev; 800 while (cur != NULL) { 801 jint cur_occ = cur->occupied(); 802 #if DRT_CENSUS 803 for (int k = 0; k < HistoSize; k++) { 804 if (cur_occ <= histo_limits[k]) { 805 histo[k]++; global_histo[k]++; break; 806 } 807 } 808 #endif 809 if (max == NULL || cur_occ > max_occ) { 810 max = cur; 811 max_prev = prev; 812 max_ind = i; 813 max_occ = cur_occ; 814 } 815 prev = cur->next_addr(); 816 cur = cur->next(); 817 } 818 } 819 #endif 820 // XXX 821 guarantee(max != NULL, "Since _n_fine_entries > 0"); 822 #if DRT_CENSUS 823 gclog_or_tty->print_cr("In a coarsening: histo of occs:"); 824 for (int k = 0; k < HistoSize; k++) { 825 gclog_or_tty->print_cr(" <= %4d: %5d.", histo_limits[k], histo[k]); 826 } 827 coarsenings++; 828 occ_sum += max_occ; 829 if ((coarsenings % 100) == 0) { 830 gclog_or_tty->print_cr("\ncoarsenings = %d; global summary:", coarsenings); 831 for (int k = 0; k < HistoSize; k++) { 832 gclog_or_tty->print_cr(" <= %4d: %5d.", histo_limits[k], global_histo[k]); 833 } 834 gclog_or_tty->print_cr("Avg occ of deleted region = %6.2f.", 835 (float)occ_sum/(float)coarsenings); 836 } 837 #endif 838 839 // Set the corresponding coarse bit. 840 size_t max_hrs_index = max->hr()->hrs_index(); 841 if (!_coarse_map.at(max_hrs_index)) { 842 _coarse_map.at_put(max_hrs_index, true); 843 _n_coarse_entries++; 844 #if 0 845 gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] " 846 "for region [" PTR_FORMAT "...] (%d coarse entries).\n", 847 hr()->bottom(), 848 max->hr()->bottom(), 849 _n_coarse_entries); 850 #endif 851 } 852 853 // Unsplice. 854 *max_prev = max->next(); 855 Atomic::inc(&_n_coarsenings); 856 _n_fine_entries--; 857 return max; 858 } 859 860 861 // At present, this must be called stop-world single-threaded. 862 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs, 863 BitMap* region_bm, BitMap* card_bm) { 864 // First eliminated garbage regions from the coarse map. 865 if (G1RSScrubVerbose) 866 gclog_or_tty->print_cr("Scrubbing region "SIZE_FORMAT":", 867 hr()->hrs_index()); 868 869 assert(_coarse_map.size() == region_bm->size(), "Precondition"); 870 if (G1RSScrubVerbose) 871 gclog_or_tty->print(" Coarse map: before = %d...", _n_coarse_entries); 872 _coarse_map.set_intersection(*region_bm); 873 _n_coarse_entries = _coarse_map.count_one_bits(); 874 if (G1RSScrubVerbose) 875 gclog_or_tty->print_cr(" after = %d.", _n_coarse_entries); 876 877 // Now do the fine-grained maps. 878 for (size_t i = 0; i < _max_fine_entries; i++) { 879 PosParPRT* cur = _fine_grain_regions[i]; 880 PosParPRT** prev = &_fine_grain_regions[i]; 881 while (cur != NULL) { 882 PosParPRT* nxt = cur->next(); 883 // If the entire region is dead, eliminate. 884 if (G1RSScrubVerbose) 885 gclog_or_tty->print_cr(" For other region "SIZE_FORMAT":", 886 cur->hr()->hrs_index()); 887 if (!region_bm->at(cur->hr()->hrs_index())) { 888 *prev = nxt; 889 cur->set_next(NULL); 890 _n_fine_entries--; 891 if (G1RSScrubVerbose) 892 gclog_or_tty->print_cr(" deleted via region map."); 893 PosParPRT::free(cur); 894 } else { 895 // Do fine-grain elimination. 896 if (G1RSScrubVerbose) 897 gclog_or_tty->print(" occ: before = %4d.", cur->occupied()); 898 cur->scrub(ctbs, card_bm); 899 if (G1RSScrubVerbose) 900 gclog_or_tty->print_cr(" after = %4d.", cur->occupied()); 901 // Did that empty the table completely? 902 if (cur->occupied() == 0) { 903 *prev = nxt; 904 cur->set_next(NULL); 905 _n_fine_entries--; 906 PosParPRT::free(cur); 907 } else { 908 prev = cur->next_addr(); 909 } 910 } 911 cur = nxt; 912 } 913 } 914 // Since we may have deleted a from_card_cache entry from the RS, clear 915 // the FCC. 916 clear_fcc(); 917 } 918 919 920 size_t OtherRegionsTable::occupied() const { 921 // Cast away const in this case. 922 MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag); 923 size_t sum = occ_fine(); 924 sum += occ_sparse(); 925 sum += occ_coarse(); 926 return sum; 927 } 928 929 size_t OtherRegionsTable::occ_fine() const { 930 size_t sum = 0; 931 for (size_t i = 0; i < _max_fine_entries; i++) { 932 PosParPRT* cur = _fine_grain_regions[i]; 933 while (cur != NULL) { 934 sum += cur->occupied(); 935 cur = cur->next(); 936 } 937 } 938 return sum; 939 } 940 941 size_t OtherRegionsTable::occ_coarse() const { 942 return (_n_coarse_entries * HeapRegion::CardsPerRegion); 943 } 944 945 size_t OtherRegionsTable::occ_sparse() const { 946 return _sparse_table.occupied(); 947 } 948 949 size_t OtherRegionsTable::mem_size() const { 950 // Cast away const in this case. 951 MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag); 952 size_t sum = 0; 953 for (size_t i = 0; i < _max_fine_entries; i++) { 954 PosParPRT* cur = _fine_grain_regions[i]; 955 while (cur != NULL) { 956 sum += cur->mem_size(); 957 cur = cur->next(); 958 } 959 } 960 sum += (sizeof(PosParPRT*) * _max_fine_entries); 961 sum += (_coarse_map.size_in_words() * HeapWordSize); 962 sum += (_sparse_table.mem_size()); 963 sum += sizeof(*this) - sizeof(_sparse_table); // Avoid double counting above. 964 return sum; 965 } 966 967 size_t OtherRegionsTable::static_mem_size() { 968 return _from_card_cache_mem_size; 969 } 970 971 size_t OtherRegionsTable::fl_mem_size() { 972 return PerRegionTable::fl_mem_size() + PosParPRT::fl_mem_size(); 973 } 974 975 void OtherRegionsTable::clear_fcc() { 976 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 977 _from_card_cache[i][hr()->hrs_index()] = -1; 978 } 979 } 980 981 void OtherRegionsTable::clear() { 982 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 983 for (size_t i = 0; i < _max_fine_entries; i++) { 984 PosParPRT* cur = _fine_grain_regions[i]; 985 while (cur != NULL) { 986 PosParPRT* nxt = cur->next(); 987 PosParPRT::free(cur); 988 cur = nxt; 989 } 990 _fine_grain_regions[i] = NULL; 991 } 992 _sparse_table.clear(); 993 _coarse_map.clear(); 994 _n_fine_entries = 0; 995 _n_coarse_entries = 0; 996 997 clear_fcc(); 998 } 999 1000 void OtherRegionsTable::clear_incoming_entry(HeapRegion* from_hr) { 1001 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 1002 size_t hrs_ind = from_hr->hrs_index(); 1003 size_t ind = hrs_ind & _mod_max_fine_entries_mask; 1004 if (del_single_region_table(ind, from_hr)) { 1005 assert(!_coarse_map.at(hrs_ind), "Inv"); 1006 } else { 1007 _coarse_map.par_at_put(hrs_ind, 0); 1008 } 1009 // Check to see if any of the fcc entries come from here. 1010 size_t hr_ind = hr()->hrs_index(); 1011 for (int tid = 0; tid < HeapRegionRemSet::num_par_rem_sets(); tid++) { 1012 int fcc_ent = _from_card_cache[tid][hr_ind]; 1013 if (fcc_ent != -1) { 1014 HeapWord* card_addr = (HeapWord*) 1015 (uintptr_t(fcc_ent) << CardTableModRefBS::card_shift); 1016 if (hr()->is_in_reserved(card_addr)) { 1017 // Clear the from card cache. 1018 _from_card_cache[tid][hr_ind] = -1; 1019 } 1020 } 1021 } 1022 } 1023 1024 bool OtherRegionsTable::del_single_region_table(size_t ind, 1025 HeapRegion* hr) { 1026 assert(0 <= ind && ind < _max_fine_entries, "Preconditions."); 1027 PosParPRT** prev_addr = &_fine_grain_regions[ind]; 1028 PosParPRT* prt = *prev_addr; 1029 while (prt != NULL && prt->hr() != hr) { 1030 prev_addr = prt->next_addr(); 1031 prt = prt->next(); 1032 } 1033 if (prt != NULL) { 1034 assert(prt->hr() == hr, "Loop postcondition."); 1035 *prev_addr = prt->next(); 1036 PosParPRT::free(prt); 1037 _n_fine_entries--; 1038 return true; 1039 } else { 1040 return false; 1041 } 1042 } 1043 1044 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const { 1045 // Cast away const in this case. 1046 MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag); 1047 return contains_reference_locked(from); 1048 } 1049 1050 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const { 1051 HeapRegion* hr = _g1h->heap_region_containing_raw(from); 1052 if (hr == NULL) return false; 1053 RegionIdx_t hr_ind = (RegionIdx_t) hr->hrs_index(); 1054 // Is this region in the coarse map? 1055 if (_coarse_map.at(hr_ind)) return true; 1056 1057 PosParPRT* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask, 1058 hr); 1059 if (prt != NULL) { 1060 return prt->contains_reference(from); 1061 1062 } else { 1063 uintptr_t from_card = 1064 (uintptr_t(from) >> CardTableModRefBS::card_shift); 1065 uintptr_t hr_bot_card_index = 1066 uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift; 1067 assert(from_card >= hr_bot_card_index, "Inv"); 1068 CardIdx_t card_index = from_card - hr_bot_card_index; 1069 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion, 1070 "Must be in range."); 1071 return _sparse_table.contains_card(hr_ind, card_index); 1072 } 1073 1074 1075 } 1076 1077 void 1078 OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) { 1079 _sparse_table.do_cleanup_work(hrrs_cleanup_task); 1080 } 1081 1082 // Determines how many threads can add records to an rset in parallel. 1083 // This can be done by either mutator threads together with the 1084 // concurrent refinement threads or GC threads. 1085 int HeapRegionRemSet::num_par_rem_sets() { 1086 return (int)MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), ParallelGCThreads); 1087 } 1088 1089 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa, 1090 HeapRegion* hr) 1091 : _bosa(bosa), _other_regions(hr) { 1092 reset_for_par_iteration(); 1093 } 1094 1095 void HeapRegionRemSet::setup_remset_size() { 1096 // Setup sparse and fine-grain tables sizes. 1097 // table_size = base * (log(region_size / 1M) + 1) 1098 int region_size_log_mb = MAX2((int)HeapRegion::LogOfHRGrainBytes - (int)LOG_M, 0); 1099 if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) { 1100 G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1); 1101 } 1102 if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) { 1103 G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1); 1104 } 1105 guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity"); 1106 } 1107 1108 bool HeapRegionRemSet::claim_iter() { 1109 if (_iter_state != Unclaimed) return false; 1110 jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed); 1111 return (res == Unclaimed); 1112 } 1113 1114 void HeapRegionRemSet::set_iter_complete() { 1115 _iter_state = Complete; 1116 } 1117 1118 bool HeapRegionRemSet::iter_is_complete() { 1119 return _iter_state == Complete; 1120 } 1121 1122 void HeapRegionRemSet::init_iterator(HeapRegionRemSetIterator* iter) const { 1123 iter->initialize(this); 1124 } 1125 1126 #ifndef PRODUCT 1127 void HeapRegionRemSet::print() const { 1128 HeapRegionRemSetIterator iter; 1129 init_iterator(&iter); 1130 size_t card_index; 1131 while (iter.has_next(card_index)) { 1132 HeapWord* card_start = 1133 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index); 1134 gclog_or_tty->print_cr(" Card " PTR_FORMAT, card_start); 1135 } 1136 // XXX 1137 if (iter.n_yielded() != occupied()) { 1138 gclog_or_tty->print_cr("Yielded disagrees with occupied:"); 1139 gclog_or_tty->print_cr(" %6d yielded (%6d coarse, %6d fine).", 1140 iter.n_yielded(), 1141 iter.n_yielded_coarse(), iter.n_yielded_fine()); 1142 gclog_or_tty->print_cr(" %6d occ (%6d coarse, %6d fine).", 1143 occupied(), occ_coarse(), occ_fine()); 1144 } 1145 guarantee(iter.n_yielded() == occupied(), 1146 "We should have yielded all the represented cards."); 1147 } 1148 #endif 1149 1150 void HeapRegionRemSet::cleanup() { 1151 SparsePRT::cleanup_all(); 1152 } 1153 1154 void HeapRegionRemSet::par_cleanup() { 1155 PosParPRT::par_contract_all(); 1156 } 1157 1158 void HeapRegionRemSet::clear() { 1159 _other_regions.clear(); 1160 assert(occupied() == 0, "Should be clear."); 1161 reset_for_par_iteration(); 1162 } 1163 1164 void HeapRegionRemSet::reset_for_par_iteration() { 1165 _iter_state = Unclaimed; 1166 _iter_claimed = 0; 1167 // It's good to check this to make sure that the two methods are in sync. 1168 assert(verify_ready_for_par_iteration(), "post-condition"); 1169 } 1170 1171 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs, 1172 BitMap* region_bm, BitMap* card_bm) { 1173 _other_regions.scrub(ctbs, region_bm, card_bm); 1174 } 1175 1176 //-------------------- Iteration -------------------- 1177 1178 HeapRegionRemSetIterator:: 1179 HeapRegionRemSetIterator() : 1180 _hrrs(NULL), 1181 _g1h(G1CollectedHeap::heap()), 1182 _bosa(NULL), 1183 _sparse_iter() { } 1184 1185 void HeapRegionRemSetIterator::initialize(const HeapRegionRemSet* hrrs) { 1186 _hrrs = hrrs; 1187 _coarse_map = &_hrrs->_other_regions._coarse_map; 1188 _fine_grain_regions = _hrrs->_other_regions._fine_grain_regions; 1189 _bosa = _hrrs->bosa(); 1190 1191 _is = Sparse; 1192 // Set these values so that we increment to the first region. 1193 _coarse_cur_region_index = -1; 1194 _coarse_cur_region_cur_card = (HeapRegion::CardsPerRegion-1); 1195 1196 _cur_region_cur_card = 0; 1197 1198 _fine_array_index = -1; 1199 _fine_cur_prt = NULL; 1200 1201 _n_yielded_coarse = 0; 1202 _n_yielded_fine = 0; 1203 _n_yielded_sparse = 0; 1204 1205 _sparse_iter.init(&hrrs->_other_regions._sparse_table); 1206 } 1207 1208 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) { 1209 if (_hrrs->_other_regions._n_coarse_entries == 0) return false; 1210 // Go to the next card. 1211 _coarse_cur_region_cur_card++; 1212 // Was the last the last card in the current region? 1213 if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) { 1214 // Yes: find the next region. This may leave _coarse_cur_region_index 1215 // Set to the last index, in which case there are no more coarse 1216 // regions. 1217 _coarse_cur_region_index = 1218 (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1); 1219 if ((size_t)_coarse_cur_region_index < _coarse_map->size()) { 1220 _coarse_cur_region_cur_card = 0; 1221 HeapWord* r_bot = 1222 _g1h->region_at(_coarse_cur_region_index)->bottom(); 1223 _cur_region_card_offset = _bosa->index_for(r_bot); 1224 } else { 1225 return false; 1226 } 1227 } 1228 // If we didn't return false above, then we can yield a card. 1229 card_index = _cur_region_card_offset + _coarse_cur_region_cur_card; 1230 return true; 1231 } 1232 1233 void HeapRegionRemSetIterator::fine_find_next_non_null_prt() { 1234 // Otherwise, find the next bucket list in the array. 1235 _fine_array_index++; 1236 while (_fine_array_index < (int) OtherRegionsTable::_max_fine_entries) { 1237 _fine_cur_prt = _fine_grain_regions[_fine_array_index]; 1238 if (_fine_cur_prt != NULL) return; 1239 else _fine_array_index++; 1240 } 1241 assert(_fine_cur_prt == NULL, "Loop post"); 1242 } 1243 1244 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) { 1245 if (fine_has_next()) { 1246 _cur_region_cur_card = 1247 _fine_cur_prt->_bm.get_next_one_offset(_cur_region_cur_card + 1); 1248 } 1249 while (!fine_has_next()) { 1250 if (_cur_region_cur_card == (size_t) HeapRegion::CardsPerRegion) { 1251 _cur_region_cur_card = 0; 1252 _fine_cur_prt = _fine_cur_prt->next(); 1253 } 1254 if (_fine_cur_prt == NULL) { 1255 fine_find_next_non_null_prt(); 1256 if (_fine_cur_prt == NULL) return false; 1257 } 1258 assert(_fine_cur_prt != NULL && _cur_region_cur_card == 0, 1259 "inv."); 1260 HeapWord* r_bot = 1261 _fine_cur_prt->hr()->bottom(); 1262 _cur_region_card_offset = _bosa->index_for(r_bot); 1263 _cur_region_cur_card = _fine_cur_prt->_bm.get_next_one_offset(0); 1264 } 1265 assert(fine_has_next(), "Or else we exited the loop via the return."); 1266 card_index = _cur_region_card_offset + _cur_region_cur_card; 1267 return true; 1268 } 1269 1270 bool HeapRegionRemSetIterator::fine_has_next() { 1271 return 1272 _fine_cur_prt != NULL && 1273 _cur_region_cur_card < HeapRegion::CardsPerRegion; 1274 } 1275 1276 bool HeapRegionRemSetIterator::has_next(size_t& card_index) { 1277 switch (_is) { 1278 case Sparse: 1279 if (_sparse_iter.has_next(card_index)) { 1280 _n_yielded_sparse++; 1281 return true; 1282 } 1283 // Otherwise, deliberate fall-through 1284 _is = Fine; 1285 case Fine: 1286 if (fine_has_next(card_index)) { 1287 _n_yielded_fine++; 1288 return true; 1289 } 1290 // Otherwise, deliberate fall-through 1291 _is = Coarse; 1292 case Coarse: 1293 if (coarse_has_next(card_index)) { 1294 _n_yielded_coarse++; 1295 return true; 1296 } 1297 // Otherwise... 1298 break; 1299 } 1300 assert(ParallelGCThreads > 1 || 1301 n_yielded() == _hrrs->occupied(), 1302 "Should have yielded all the cards in the rem set " 1303 "(in the non-par case)."); 1304 return false; 1305 } 1306 1307 1308 1309 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL; 1310 HeapWord** HeapRegionRemSet::_recorded_cards = NULL; 1311 HeapRegion** HeapRegionRemSet::_recorded_regions = NULL; 1312 int HeapRegionRemSet::_n_recorded = 0; 1313 1314 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL; 1315 int* HeapRegionRemSet::_recorded_event_index = NULL; 1316 int HeapRegionRemSet::_n_recorded_events = 0; 1317 1318 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) { 1319 if (_recorded_oops == NULL) { 1320 assert(_n_recorded == 0 1321 && _recorded_cards == NULL 1322 && _recorded_regions == NULL, 1323 "Inv"); 1324 _recorded_oops = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded); 1325 _recorded_cards = NEW_C_HEAP_ARRAY(HeapWord*, MaxRecorded); 1326 _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*, MaxRecorded); 1327 } 1328 if (_n_recorded == MaxRecorded) { 1329 gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded); 1330 } else { 1331 _recorded_cards[_n_recorded] = 1332 (HeapWord*)align_size_down(uintptr_t(f), 1333 CardTableModRefBS::card_size); 1334 _recorded_oops[_n_recorded] = f; 1335 _recorded_regions[_n_recorded] = hr; 1336 _n_recorded++; 1337 } 1338 } 1339 1340 void HeapRegionRemSet::record_event(Event evnt) { 1341 if (!G1RecordHRRSEvents) return; 1342 1343 if (_recorded_events == NULL) { 1344 assert(_n_recorded_events == 0 1345 && _recorded_event_index == NULL, 1346 "Inv"); 1347 _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents); 1348 _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents); 1349 } 1350 if (_n_recorded_events == MaxRecordedEvents) { 1351 gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents); 1352 } else { 1353 _recorded_events[_n_recorded_events] = evnt; 1354 _recorded_event_index[_n_recorded_events] = _n_recorded; 1355 _n_recorded_events++; 1356 } 1357 } 1358 1359 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) { 1360 switch (evnt) { 1361 case Event_EvacStart: 1362 str->print("Evac Start"); 1363 break; 1364 case Event_EvacEnd: 1365 str->print("Evac End"); 1366 break; 1367 case Event_RSUpdateEnd: 1368 str->print("RS Update End"); 1369 break; 1370 } 1371 } 1372 1373 void HeapRegionRemSet::print_recorded() { 1374 int cur_evnt = 0; 1375 Event cur_evnt_kind; 1376 int cur_evnt_ind = 0; 1377 if (_n_recorded_events > 0) { 1378 cur_evnt_kind = _recorded_events[cur_evnt]; 1379 cur_evnt_ind = _recorded_event_index[cur_evnt]; 1380 } 1381 1382 for (int i = 0; i < _n_recorded; i++) { 1383 while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) { 1384 gclog_or_tty->print("Event: "); 1385 print_event(gclog_or_tty, cur_evnt_kind); 1386 gclog_or_tty->print_cr(""); 1387 cur_evnt++; 1388 if (cur_evnt < MaxRecordedEvents) { 1389 cur_evnt_kind = _recorded_events[cur_evnt]; 1390 cur_evnt_ind = _recorded_event_index[cur_evnt]; 1391 } 1392 } 1393 gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]" 1394 " for ref " PTR_FORMAT ".\n", 1395 _recorded_cards[i], _recorded_regions[i]->bottom(), 1396 _recorded_oops[i]); 1397 } 1398 } 1399 1400 void HeapRegionRemSet::reset_for_cleanup_tasks() { 1401 SparsePRT::reset_for_cleanup_tasks(); 1402 } 1403 1404 void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) { 1405 _other_regions.do_cleanup_work(hrrs_cleanup_task); 1406 } 1407 1408 void 1409 HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) { 1410 SparsePRT::finish_cleanup_task(hrrs_cleanup_task); 1411 } 1412 1413 #ifndef PRODUCT 1414 void HeapRegionRemSet::test() { 1415 os::sleep(Thread::current(), (jlong)5000, false); 1416 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 1417 1418 // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same 1419 // hash bucket. 1420 HeapRegion* hr0 = g1h->region_at(0); 1421 HeapRegion* hr1 = g1h->region_at(1); 1422 HeapRegion* hr2 = g1h->region_at(5); 1423 HeapRegion* hr3 = g1h->region_at(6); 1424 HeapRegion* hr4 = g1h->region_at(7); 1425 HeapRegion* hr5 = g1h->region_at(8); 1426 1427 HeapWord* hr1_start = hr1->bottom(); 1428 HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2; 1429 HeapWord* hr1_last = hr1->end() - 1; 1430 1431 HeapWord* hr2_start = hr2->bottom(); 1432 HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2; 1433 HeapWord* hr2_last = hr2->end() - 1; 1434 1435 HeapWord* hr3_start = hr3->bottom(); 1436 HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2; 1437 HeapWord* hr3_last = hr3->end() - 1; 1438 1439 HeapRegionRemSet* hrrs = hr0->rem_set(); 1440 1441 // Make three references from region 0x101... 1442 hrrs->add_reference((OopOrNarrowOopStar)hr1_start); 1443 hrrs->add_reference((OopOrNarrowOopStar)hr1_mid); 1444 hrrs->add_reference((OopOrNarrowOopStar)hr1_last); 1445 1446 hrrs->add_reference((OopOrNarrowOopStar)hr2_start); 1447 hrrs->add_reference((OopOrNarrowOopStar)hr2_mid); 1448 hrrs->add_reference((OopOrNarrowOopStar)hr2_last); 1449 1450 hrrs->add_reference((OopOrNarrowOopStar)hr3_start); 1451 hrrs->add_reference((OopOrNarrowOopStar)hr3_mid); 1452 hrrs->add_reference((OopOrNarrowOopStar)hr3_last); 1453 1454 // Now cause a coarsening. 1455 hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom()); 1456 hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom()); 1457 1458 // Now, does iteration yield these three? 1459 HeapRegionRemSetIterator iter; 1460 hrrs->init_iterator(&iter); 1461 size_t sum = 0; 1462 size_t card_index; 1463 while (iter.has_next(card_index)) { 1464 HeapWord* card_start = 1465 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index); 1466 gclog_or_tty->print_cr(" Card " PTR_FORMAT ".", card_start); 1467 sum++; 1468 } 1469 guarantee(sum == 11 - 3 + 2048, "Failure"); 1470 guarantee(sum == hrrs->occupied(), "Failure"); 1471 } 1472 #endif