1 /* 2 * Copyright (c) 2001, 2009, 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 "incls/_precompiled.incl" 26 #include "incls/_heapRegionRemSet.cpp.incl" 27 28 #define HRRS_VERBOSE 0 29 30 #define PRT_COUNT_OCCUPIED 1 31 32 // OtherRegionsTable 33 34 class PerRegionTable: public CHeapObj { 35 friend class OtherRegionsTable; 36 friend class HeapRegionRemSetIterator; 37 38 HeapRegion* _hr; 39 BitMap _bm; 40 #if PRT_COUNT_OCCUPIED 41 jint _occupied; 42 #endif 43 PerRegionTable* _next_free; 44 45 PerRegionTable* next_free() { return _next_free; } 46 void set_next_free(PerRegionTable* prt) { _next_free = prt; } 47 48 49 static PerRegionTable* _free_list; 50 51 #ifdef _MSC_VER 52 // For some reason even though the classes are marked as friend they are unable 53 // to access CardsPerRegion when private/protected. Only the windows c++ compiler 54 // says this Sun CC and linux gcc don't have a problem with access when private 55 56 public: 57 58 #endif // _MSC_VER 59 60 protected: 61 // We need access in order to union things into the base table. 62 BitMap* bm() { return &_bm; } 63 64 #if PRT_COUNT_OCCUPIED 65 void recount_occupied() { 66 _occupied = (jint) bm()->count_one_bits(); 67 } 68 #endif 69 70 PerRegionTable(HeapRegion* hr) : 71 _hr(hr), 72 #if PRT_COUNT_OCCUPIED 73 _occupied(0), 74 #endif 75 _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */) 76 {} 77 78 static void free(PerRegionTable* prt) { 79 while (true) { 80 PerRegionTable* fl = _free_list; 81 prt->set_next_free(fl); 82 PerRegionTable* res = 83 (PerRegionTable*) 84 Atomic::cmpxchg_ptr(prt, &_free_list, fl); 85 if (res == fl) return; 86 } 87 ShouldNotReachHere(); 88 } 89 90 static PerRegionTable* alloc(HeapRegion* hr) { 91 PerRegionTable* fl = _free_list; 92 while (fl != NULL) { 93 PerRegionTable* nxt = fl->next_free(); 94 PerRegionTable* res = 95 (PerRegionTable*) 96 Atomic::cmpxchg_ptr(nxt, &_free_list, fl); 97 if (res == fl) { 98 fl->init(hr); 99 return fl; 100 } else { 101 fl = _free_list; 102 } 103 } 104 assert(fl == NULL, "Loop condition."); 105 return new PerRegionTable(hr); 106 } 107 108 void add_card_work(CardIdx_t from_card, bool par) { 109 if (!_bm.at(from_card)) { 110 if (par) { 111 if (_bm.par_at_put(from_card, 1)) { 112 #if PRT_COUNT_OCCUPIED 113 Atomic::inc(&_occupied); 114 #endif 115 } 116 } else { 117 _bm.at_put(from_card, 1); 118 #if PRT_COUNT_OCCUPIED 119 _occupied++; 120 #endif 121 } 122 } 123 } 124 125 void add_reference_work(OopOrNarrowOopStar from, bool par) { 126 // Must make this robust in case "from" is not in "_hr", because of 127 // concurrency. 128 129 #if HRRS_VERBOSE 130 gclog_or_tty->print_cr(" PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").", 131 from, *from); 132 #endif 133 134 HeapRegion* loc_hr = hr(); 135 // If the test below fails, then this table was reused concurrently 136 // with this operation. This is OK, since the old table was coarsened, 137 // and adding a bit to the new table is never incorrect. 138 if (loc_hr->is_in_reserved(from)) { 139 size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom()); 140 CardIdx_t from_card = (CardIdx_t) 141 hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize); 142 143 assert(0 <= from_card && from_card < HeapRegion::CardsPerRegion, 144 "Must be in range."); 145 add_card_work(from_card, par); 146 } 147 } 148 149 public: 150 151 HeapRegion* hr() const { return _hr; } 152 153 #if PRT_COUNT_OCCUPIED 154 jint occupied() const { 155 // Overkill, but if we ever need it... 156 // guarantee(_occupied == _bm.count_one_bits(), "Check"); 157 return _occupied; 158 } 159 #else 160 jint occupied() const { 161 return _bm.count_one_bits(); 162 } 163 #endif 164 165 void init(HeapRegion* hr) { 166 _hr = hr; 167 #if PRT_COUNT_OCCUPIED 168 _occupied = 0; 169 #endif 170 _bm.clear(); 171 } 172 173 void add_reference(OopOrNarrowOopStar from) { 174 add_reference_work(from, /*parallel*/ true); 175 } 176 177 void seq_add_reference(OopOrNarrowOopStar from) { 178 add_reference_work(from, /*parallel*/ false); 179 } 180 181 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) { 182 HeapWord* hr_bot = hr()->bottom(); 183 size_t hr_first_card_index = ctbs->index_for(hr_bot); 184 bm()->set_intersection_at_offset(*card_bm, hr_first_card_index); 185 #if PRT_COUNT_OCCUPIED 186 recount_occupied(); 187 #endif 188 } 189 190 void add_card(CardIdx_t from_card_index) { 191 add_card_work(from_card_index, /*parallel*/ true); 192 } 193 194 void seq_add_card(CardIdx_t from_card_index) { 195 add_card_work(from_card_index, /*parallel*/ false); 196 } 197 198 // (Destructively) union the bitmap of the current table into the given 199 // bitmap (which is assumed to be of the same size.) 200 void union_bitmap_into(BitMap* bm) { 201 bm->set_union(_bm); 202 } 203 204 // Mem size in bytes. 205 size_t mem_size() const { 206 return sizeof(this) + _bm.size_in_words() * HeapWordSize; 207 } 208 209 static size_t fl_mem_size() { 210 PerRegionTable* cur = _free_list; 211 size_t res = 0; 212 while (cur != NULL) { 213 res += sizeof(PerRegionTable); 214 cur = cur->next_free(); 215 } 216 return res; 217 } 218 219 // Requires "from" to be in "hr()". 220 bool contains_reference(OopOrNarrowOopStar from) const { 221 assert(hr()->is_in_reserved(from), "Precondition."); 222 size_t card_ind = pointer_delta(from, hr()->bottom(), 223 CardTableModRefBS::card_size); 224 return _bm.at(card_ind); 225 } 226 }; 227 228 PerRegionTable* PerRegionTable::_free_list = NULL; 229 230 231 #define COUNT_PAR_EXPANDS 0 232 233 #if COUNT_PAR_EXPANDS 234 static jint n_par_expands = 0; 235 static jint n_par_contracts = 0; 236 static jint par_expand_list_len = 0; 237 static jint max_par_expand_list_len = 0; 238 239 static void print_par_expand() { 240 Atomic::inc(&n_par_expands); 241 Atomic::inc(&par_expand_list_len); 242 if (par_expand_list_len > max_par_expand_list_len) { 243 max_par_expand_list_len = par_expand_list_len; 244 } 245 if ((n_par_expands % 10) == 0) { 246 gclog_or_tty->print_cr("\n\n%d par expands: %d contracts, " 247 "len = %d, max_len = %d\n.", 248 n_par_expands, n_par_contracts, par_expand_list_len, 249 max_par_expand_list_len); 250 } 251 } 252 #endif 253 254 class PosParPRT: public PerRegionTable { 255 PerRegionTable** _par_tables; 256 257 enum SomePrivateConstants { 258 ReserveParTableExpansion = 1 259 }; 260 261 void par_contract() { 262 assert(_par_tables != NULL, "Precondition."); 263 int n = HeapRegionRemSet::num_par_rem_sets()-1; 264 for (int i = 0; i < n; i++) { 265 _par_tables[i]->union_bitmap_into(bm()); 266 PerRegionTable::free(_par_tables[i]); 267 _par_tables[i] = NULL; 268 } 269 #if PRT_COUNT_OCCUPIED 270 // We must recount the "occupied." 271 recount_occupied(); 272 #endif 273 FREE_C_HEAP_ARRAY(PerRegionTable*, _par_tables); 274 _par_tables = NULL; 275 #if COUNT_PAR_EXPANDS 276 Atomic::inc(&n_par_contracts); 277 Atomic::dec(&par_expand_list_len); 278 #endif 279 } 280 281 static PerRegionTable** _par_table_fl; 282 283 PosParPRT* _next; 284 285 static PosParPRT* _free_list; 286 287 PerRegionTable** par_tables() const { 288 assert(uintptr_t(NULL) == 0, "Assumption."); 289 if (uintptr_t(_par_tables) <= ReserveParTableExpansion) 290 return NULL; 291 else 292 return _par_tables; 293 } 294 295 PosParPRT* _next_par_expanded; 296 PosParPRT* next_par_expanded() { return _next_par_expanded; } 297 void set_next_par_expanded(PosParPRT* ppprt) { _next_par_expanded = ppprt; } 298 static PosParPRT* _par_expanded_list; 299 300 public: 301 302 PosParPRT(HeapRegion* hr) : PerRegionTable(hr), _par_tables(NULL) {} 303 304 jint occupied() const { 305 jint res = PerRegionTable::occupied(); 306 if (par_tables() != NULL) { 307 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) { 308 res += par_tables()[i]->occupied(); 309 } 310 } 311 return res; 312 } 313 314 void init(HeapRegion* hr) { 315 PerRegionTable::init(hr); 316 _next = NULL; 317 if (par_tables() != NULL) { 318 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) { 319 par_tables()[i]->init(hr); 320 } 321 } 322 } 323 324 static void free(PosParPRT* prt) { 325 while (true) { 326 PosParPRT* fl = _free_list; 327 prt->set_next(fl); 328 PosParPRT* res = 329 (PosParPRT*) 330 Atomic::cmpxchg_ptr(prt, &_free_list, fl); 331 if (res == fl) return; 332 } 333 ShouldNotReachHere(); 334 } 335 336 static PosParPRT* alloc(HeapRegion* hr) { 337 PosParPRT* fl = _free_list; 338 while (fl != NULL) { 339 PosParPRT* nxt = fl->next(); 340 PosParPRT* res = 341 (PosParPRT*) 342 Atomic::cmpxchg_ptr(nxt, &_free_list, fl); 343 if (res == fl) { 344 fl->init(hr); 345 return fl; 346 } else { 347 fl = _free_list; 348 } 349 } 350 assert(fl == NULL, "Loop condition."); 351 return new PosParPRT(hr); 352 } 353 354 PosParPRT* next() const { return _next; } 355 void set_next(PosParPRT* nxt) { _next = nxt; } 356 PosParPRT** next_addr() { return &_next; } 357 358 bool should_expand(int tid) { 359 return par_tables() == NULL && tid > 0 && hr()->is_gc_alloc_region(); 360 } 361 362 void par_expand() { 363 int n = HeapRegionRemSet::num_par_rem_sets()-1; 364 if (n <= 0) return; 365 if (_par_tables == NULL) { 366 PerRegionTable* res = 367 (PerRegionTable*) 368 Atomic::cmpxchg_ptr((PerRegionTable*)ReserveParTableExpansion, 369 &_par_tables, NULL); 370 if (res != NULL) return; 371 // Otherwise, we reserved the right to do the expansion. 372 373 PerRegionTable** ptables = NEW_C_HEAP_ARRAY(PerRegionTable*, n); 374 for (int i = 0; i < n; i++) { 375 PerRegionTable* ptable = PerRegionTable::alloc(hr()); 376 ptables[i] = ptable; 377 } 378 // Here we do not need an atomic. 379 _par_tables = ptables; 380 #if COUNT_PAR_EXPANDS 381 print_par_expand(); 382 #endif 383 // We must put this table on the expanded list. 384 PosParPRT* exp_head = _par_expanded_list; 385 while (true) { 386 set_next_par_expanded(exp_head); 387 PosParPRT* res = 388 (PosParPRT*) 389 Atomic::cmpxchg_ptr(this, &_par_expanded_list, exp_head); 390 if (res == exp_head) return; 391 // Otherwise. 392 exp_head = res; 393 } 394 ShouldNotReachHere(); 395 } 396 } 397 398 void add_reference(OopOrNarrowOopStar from, int tid) { 399 // Expand if necessary. 400 PerRegionTable** pt = par_tables(); 401 if (pt != NULL) { 402 // We always have to assume that mods to table 0 are in parallel, 403 // because of the claiming scheme in parallel expansion. A thread 404 // with tid != 0 that finds the table to be NULL, but doesn't succeed 405 // in claiming the right of expanding it, will end up in the else 406 // clause of the above if test. That thread could be delayed, and a 407 // thread 0 add reference could see the table expanded, and come 408 // here. Both threads would be adding in parallel. But we get to 409 // not use atomics for tids > 0. 410 if (tid == 0) { 411 PerRegionTable::add_reference(from); 412 } else { 413 pt[tid-1]->seq_add_reference(from); 414 } 415 } else { 416 // Not expanded -- add to the base table. 417 PerRegionTable::add_reference(from); 418 } 419 } 420 421 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) { 422 assert(_par_tables == NULL, "Precondition"); 423 PerRegionTable::scrub(ctbs, card_bm); 424 } 425 426 size_t mem_size() const { 427 size_t res = 428 PerRegionTable::mem_size() + sizeof(this) - sizeof(PerRegionTable); 429 if (_par_tables != NULL) { 430 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) { 431 res += _par_tables[i]->mem_size(); 432 } 433 } 434 return res; 435 } 436 437 static size_t fl_mem_size() { 438 PosParPRT* cur = _free_list; 439 size_t res = 0; 440 while (cur != NULL) { 441 res += sizeof(PosParPRT); 442 cur = cur->next(); 443 } 444 return res; 445 } 446 447 bool contains_reference(OopOrNarrowOopStar from) const { 448 if (PerRegionTable::contains_reference(from)) return true; 449 if (_par_tables != NULL) { 450 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) { 451 if (_par_tables[i]->contains_reference(from)) return true; 452 } 453 } 454 return false; 455 } 456 457 static void par_contract_all(); 458 459 }; 460 461 void PosParPRT::par_contract_all() { 462 PosParPRT* hd = _par_expanded_list; 463 while (hd != NULL) { 464 PosParPRT* nxt = hd->next_par_expanded(); 465 PosParPRT* res = 466 (PosParPRT*) 467 Atomic::cmpxchg_ptr(nxt, &_par_expanded_list, hd); 468 if (res == hd) { 469 // We claimed the right to contract this table. 470 hd->set_next_par_expanded(NULL); 471 hd->par_contract(); 472 hd = _par_expanded_list; 473 } else { 474 hd = res; 475 } 476 } 477 } 478 479 PosParPRT* PosParPRT::_free_list = NULL; 480 PosParPRT* PosParPRT::_par_expanded_list = NULL; 481 482 jint OtherRegionsTable::_cache_probes = 0; 483 jint OtherRegionsTable::_cache_hits = 0; 484 485 size_t OtherRegionsTable::_max_fine_entries = 0; 486 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0; 487 #if SAMPLE_FOR_EVICTION 488 size_t OtherRegionsTable::_fine_eviction_stride = 0; 489 size_t OtherRegionsTable::_fine_eviction_sample_size = 0; 490 #endif 491 492 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr) : 493 _g1h(G1CollectedHeap::heap()), 494 _m(Mutex::leaf, "An OtherRegionsTable lock", true), 495 _hr(hr), 496 _coarse_map(G1CollectedHeap::heap()->max_regions(), 497 false /* in-resource-area */), 498 _fine_grain_regions(NULL), 499 _n_fine_entries(0), _n_coarse_entries(0), 500 #if SAMPLE_FOR_EVICTION 501 _fine_eviction_start(0), 502 #endif 503 _sparse_table(hr) 504 { 505 typedef PosParPRT* PosParPRTPtr; 506 if (_max_fine_entries == 0) { 507 assert(_mod_max_fine_entries_mask == 0, "Both or none."); 508 size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries); 509 _max_fine_entries = (size_t)(1 << max_entries_log); 510 _mod_max_fine_entries_mask = _max_fine_entries - 1; 511 #if SAMPLE_FOR_EVICTION 512 assert(_fine_eviction_sample_size == 0 513 && _fine_eviction_stride == 0, "All init at same time."); 514 _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log); 515 _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size; 516 #endif 517 } 518 _fine_grain_regions = new PosParPRTPtr[_max_fine_entries]; 519 if (_fine_grain_regions == NULL) 520 vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, 521 "Failed to allocate _fine_grain_entries."); 522 for (size_t i = 0; i < _max_fine_entries; i++) { 523 _fine_grain_regions[i] = NULL; 524 } 525 } 526 527 int** OtherRegionsTable::_from_card_cache = NULL; 528 size_t OtherRegionsTable::_from_card_cache_max_regions = 0; 529 size_t OtherRegionsTable::_from_card_cache_mem_size = 0; 530 531 void OtherRegionsTable::init_from_card_cache(size_t max_regions) { 532 _from_card_cache_max_regions = max_regions; 533 534 int n_par_rs = HeapRegionRemSet::num_par_rem_sets(); 535 _from_card_cache = NEW_C_HEAP_ARRAY(int*, n_par_rs); 536 for (int i = 0; i < n_par_rs; i++) { 537 _from_card_cache[i] = NEW_C_HEAP_ARRAY(int, max_regions); 538 for (size_t j = 0; j < max_regions; j++) { 539 _from_card_cache[i][j] = -1; // An invalid value. 540 } 541 } 542 _from_card_cache_mem_size = n_par_rs * max_regions * sizeof(int); 543 } 544 545 void OtherRegionsTable::shrink_from_card_cache(size_t new_n_regs) { 546 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 547 assert(new_n_regs <= _from_card_cache_max_regions, "Must be within max."); 548 for (size_t j = new_n_regs; j < _from_card_cache_max_regions; j++) { 549 _from_card_cache[i][j] = -1; // An invalid value. 550 } 551 } 552 } 553 554 #ifndef PRODUCT 555 void OtherRegionsTable::print_from_card_cache() { 556 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 557 for (size_t j = 0; j < _from_card_cache_max_regions; j++) { 558 gclog_or_tty->print_cr("_from_card_cache[%d][%d] = %d.", 559 i, j, _from_card_cache[i][j]); 560 } 561 } 562 } 563 #endif 564 565 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, int tid) { 566 size_t cur_hrs_ind = hr()->hrs_index(); 567 568 #if HRRS_VERBOSE 569 gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").", 570 from, 571 UseCompressedOops 572 ? oopDesc::load_decode_heap_oop((narrowOop*)from) 573 : oopDesc::load_decode_heap_oop((oop*)from)); 574 #endif 575 576 int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift); 577 578 #if HRRS_VERBOSE 579 gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)", 580 hr()->bottom(), from_card, 581 _from_card_cache[tid][cur_hrs_ind]); 582 #endif 583 584 #define COUNT_CACHE 0 585 #if COUNT_CACHE 586 jint p = Atomic::add(1, &_cache_probes); 587 if ((p % 10000) == 0) { 588 jint hits = _cache_hits; 589 gclog_or_tty->print_cr("%d/%d = %5.2f%% RS cache hits.", 590 _cache_hits, p, 100.0* (float)hits/(float)p); 591 } 592 #endif 593 if (from_card == _from_card_cache[tid][cur_hrs_ind]) { 594 #if HRRS_VERBOSE 595 gclog_or_tty->print_cr(" from-card cache hit."); 596 #endif 597 #if COUNT_CACHE 598 Atomic::inc(&_cache_hits); 599 #endif 600 assert(contains_reference(from), "We just added it!"); 601 return; 602 } else { 603 _from_card_cache[tid][cur_hrs_ind] = from_card; 604 } 605 606 // Note that this may be a continued H region. 607 HeapRegion* from_hr = _g1h->heap_region_containing_raw(from); 608 RegionIdx_t from_hrs_ind = (RegionIdx_t) from_hr->hrs_index(); 609 610 // If the region is already coarsened, return. 611 if (_coarse_map.at(from_hrs_ind)) { 612 #if HRRS_VERBOSE 613 gclog_or_tty->print_cr(" coarse map hit."); 614 #endif 615 assert(contains_reference(from), "We just added it!"); 616 return; 617 } 618 619 // Otherwise find a per-region table to add it to. 620 size_t ind = from_hrs_ind & _mod_max_fine_entries_mask; 621 PosParPRT* prt = find_region_table(ind, from_hr); 622 if (prt == NULL) { 623 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 624 // Confirm that it's really not there... 625 prt = find_region_table(ind, from_hr); 626 if (prt == NULL) { 627 628 uintptr_t from_hr_bot_card_index = 629 uintptr_t(from_hr->bottom()) 630 >> CardTableModRefBS::card_shift; 631 CardIdx_t card_index = from_card - from_hr_bot_card_index; 632 assert(0 <= card_index && card_index < HeapRegion::CardsPerRegion, 633 "Must be in range."); 634 if (G1HRRSUseSparseTable && 635 _sparse_table.add_card(from_hrs_ind, card_index)) { 636 if (G1RecordHRRSOops) { 637 HeapRegionRemSet::record(hr(), from); 638 #if HRRS_VERBOSE 639 gclog_or_tty->print(" Added card " PTR_FORMAT " to region " 640 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n", 641 align_size_down(uintptr_t(from), 642 CardTableModRefBS::card_size), 643 hr()->bottom(), from); 644 #endif 645 } 646 #if HRRS_VERBOSE 647 gclog_or_tty->print_cr(" added card to sparse table."); 648 #endif 649 assert(contains_reference_locked(from), "We just added it!"); 650 return; 651 } else { 652 #if HRRS_VERBOSE 653 gclog_or_tty->print_cr(" [tid %d] sparse table entry " 654 "overflow(f: %d, t: %d)", 655 tid, from_hrs_ind, cur_hrs_ind); 656 #endif 657 } 658 659 if (_n_fine_entries == _max_fine_entries) { 660 prt = delete_region_table(); 661 } else { 662 prt = PosParPRT::alloc(from_hr); 663 } 664 prt->init(from_hr); 665 666 PosParPRT* first_prt = _fine_grain_regions[ind]; 667 prt->set_next(first_prt); // XXX Maybe move to init? 668 _fine_grain_regions[ind] = prt; 669 _n_fine_entries++; 670 671 if (G1HRRSUseSparseTable) { 672 // Transfer from sparse to fine-grain. 673 SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrs_ind); 674 assert(sprt_entry != NULL, "There should have been an entry"); 675 for (int i = 0; i < SparsePRTEntry::cards_num(); i++) { 676 CardIdx_t c = sprt_entry->card(i); 677 if (c != SparsePRTEntry::NullEntry) { 678 prt->add_card(c); 679 } 680 } 681 // Now we can delete the sparse entry. 682 bool res = _sparse_table.delete_entry(from_hrs_ind); 683 assert(res, "It should have been there."); 684 } 685 } 686 assert(prt != NULL && prt->hr() == from_hr, "consequence"); 687 } 688 // Note that we can't assert "prt->hr() == from_hr", because of the 689 // possibility of concurrent reuse. But see head comment of 690 // OtherRegionsTable for why this is OK. 691 assert(prt != NULL, "Inv"); 692 693 if (prt->should_expand(tid)) { 694 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 695 HeapRegion* prt_hr = prt->hr(); 696 if (prt_hr == from_hr) { 697 // Make sure the table still corresponds to the same region 698 prt->par_expand(); 699 prt->add_reference(from, tid); 700 } 701 // else: The table has been concurrently coarsened, evicted, and 702 // the table data structure re-used for another table. So, we 703 // don't need to add the reference any more given that the table 704 // has been coarsened and the whole region will be scanned anyway. 705 } else { 706 prt->add_reference(from, tid); 707 } 708 if (G1RecordHRRSOops) { 709 HeapRegionRemSet::record(hr(), from); 710 #if HRRS_VERBOSE 711 gclog_or_tty->print("Added card " PTR_FORMAT " to region " 712 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n", 713 align_size_down(uintptr_t(from), 714 CardTableModRefBS::card_size), 715 hr()->bottom(), from); 716 #endif 717 } 718 assert(contains_reference(from), "We just added it!"); 719 } 720 721 PosParPRT* 722 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const { 723 assert(0 <= ind && ind < _max_fine_entries, "Preconditions."); 724 PosParPRT* prt = _fine_grain_regions[ind]; 725 while (prt != NULL && prt->hr() != hr) { 726 prt = prt->next(); 727 } 728 // Loop postcondition is the method postcondition. 729 return prt; 730 } 731 732 733 #define DRT_CENSUS 0 734 735 #if DRT_CENSUS 736 static const int HistoSize = 6; 737 static int global_histo[HistoSize] = { 0, 0, 0, 0, 0, 0 }; 738 static int coarsenings = 0; 739 static int occ_sum = 0; 740 #endif 741 742 jint OtherRegionsTable::_n_coarsenings = 0; 743 744 PosParPRT* OtherRegionsTable::delete_region_table() { 745 #if DRT_CENSUS 746 int histo[HistoSize] = { 0, 0, 0, 0, 0, 0 }; 747 const int histo_limits[] = { 1, 4, 16, 64, 256, 2048 }; 748 #endif 749 750 assert(_m.owned_by_self(), "Precondition"); 751 assert(_n_fine_entries == _max_fine_entries, "Precondition"); 752 PosParPRT* max = NULL; 753 jint max_occ = 0; 754 PosParPRT** max_prev; 755 size_t max_ind; 756 757 #if SAMPLE_FOR_EVICTION 758 size_t i = _fine_eviction_start; 759 for (size_t k = 0; k < _fine_eviction_sample_size; k++) { 760 size_t ii = i; 761 // Make sure we get a non-NULL sample. 762 while (_fine_grain_regions[ii] == NULL) { 763 ii++; 764 if (ii == _max_fine_entries) ii = 0; 765 guarantee(ii != i, "We must find one."); 766 } 767 PosParPRT** prev = &_fine_grain_regions[ii]; 768 PosParPRT* cur = *prev; 769 while (cur != NULL) { 770 jint cur_occ = cur->occupied(); 771 if (max == NULL || cur_occ > max_occ) { 772 max = cur; 773 max_prev = prev; 774 max_ind = i; 775 max_occ = cur_occ; 776 } 777 prev = cur->next_addr(); 778 cur = cur->next(); 779 } 780 i = i + _fine_eviction_stride; 781 if (i >= _n_fine_entries) i = i - _n_fine_entries; 782 } 783 _fine_eviction_start++; 784 if (_fine_eviction_start >= _n_fine_entries) 785 _fine_eviction_start -= _n_fine_entries; 786 #else 787 for (int i = 0; i < _max_fine_entries; i++) { 788 PosParPRT** prev = &_fine_grain_regions[i]; 789 PosParPRT* cur = *prev; 790 while (cur != NULL) { 791 jint cur_occ = cur->occupied(); 792 #if DRT_CENSUS 793 for (int k = 0; k < HistoSize; k++) { 794 if (cur_occ <= histo_limits[k]) { 795 histo[k]++; global_histo[k]++; break; 796 } 797 } 798 #endif 799 if (max == NULL || cur_occ > max_occ) { 800 max = cur; 801 max_prev = prev; 802 max_ind = i; 803 max_occ = cur_occ; 804 } 805 prev = cur->next_addr(); 806 cur = cur->next(); 807 } 808 } 809 #endif 810 // XXX 811 guarantee(max != NULL, "Since _n_fine_entries > 0"); 812 #if DRT_CENSUS 813 gclog_or_tty->print_cr("In a coarsening: histo of occs:"); 814 for (int k = 0; k < HistoSize; k++) { 815 gclog_or_tty->print_cr(" <= %4d: %5d.", histo_limits[k], histo[k]); 816 } 817 coarsenings++; 818 occ_sum += max_occ; 819 if ((coarsenings % 100) == 0) { 820 gclog_or_tty->print_cr("\ncoarsenings = %d; global summary:", coarsenings); 821 for (int k = 0; k < HistoSize; k++) { 822 gclog_or_tty->print_cr(" <= %4d: %5d.", histo_limits[k], global_histo[k]); 823 } 824 gclog_or_tty->print_cr("Avg occ of deleted region = %6.2f.", 825 (float)occ_sum/(float)coarsenings); 826 } 827 #endif 828 829 // Set the corresponding coarse bit. 830 int max_hrs_index = max->hr()->hrs_index(); 831 if (!_coarse_map.at(max_hrs_index)) { 832 _coarse_map.at_put(max_hrs_index, true); 833 _n_coarse_entries++; 834 #if 0 835 gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] " 836 "for region [" PTR_FORMAT "...] (%d coarse entries).\n", 837 hr()->bottom(), 838 max->hr()->bottom(), 839 _n_coarse_entries); 840 #endif 841 } 842 843 // Unsplice. 844 *max_prev = max->next(); 845 Atomic::inc(&_n_coarsenings); 846 _n_fine_entries--; 847 return max; 848 } 849 850 851 // At present, this must be called stop-world single-threaded. 852 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs, 853 BitMap* region_bm, BitMap* card_bm) { 854 // First eliminated garbage regions from the coarse map. 855 if (G1RSScrubVerbose) 856 gclog_or_tty->print_cr("Scrubbing region %d:", hr()->hrs_index()); 857 858 assert(_coarse_map.size() == region_bm->size(), "Precondition"); 859 if (G1RSScrubVerbose) 860 gclog_or_tty->print(" Coarse map: before = %d...", _n_coarse_entries); 861 _coarse_map.set_intersection(*region_bm); 862 _n_coarse_entries = _coarse_map.count_one_bits(); 863 if (G1RSScrubVerbose) 864 gclog_or_tty->print_cr(" after = %d.", _n_coarse_entries); 865 866 // Now do the fine-grained maps. 867 for (size_t i = 0; i < _max_fine_entries; i++) { 868 PosParPRT* cur = _fine_grain_regions[i]; 869 PosParPRT** prev = &_fine_grain_regions[i]; 870 while (cur != NULL) { 871 PosParPRT* nxt = cur->next(); 872 // If the entire region is dead, eliminate. 873 if (G1RSScrubVerbose) 874 gclog_or_tty->print_cr(" For other region %d:", cur->hr()->hrs_index()); 875 if (!region_bm->at(cur->hr()->hrs_index())) { 876 *prev = nxt; 877 cur->set_next(NULL); 878 _n_fine_entries--; 879 if (G1RSScrubVerbose) 880 gclog_or_tty->print_cr(" deleted via region map."); 881 PosParPRT::free(cur); 882 } else { 883 // Do fine-grain elimination. 884 if (G1RSScrubVerbose) 885 gclog_or_tty->print(" occ: before = %4d.", cur->occupied()); 886 cur->scrub(ctbs, card_bm); 887 if (G1RSScrubVerbose) 888 gclog_or_tty->print_cr(" after = %4d.", cur->occupied()); 889 // Did that empty the table completely? 890 if (cur->occupied() == 0) { 891 *prev = nxt; 892 cur->set_next(NULL); 893 _n_fine_entries--; 894 PosParPRT::free(cur); 895 } else { 896 prev = cur->next_addr(); 897 } 898 } 899 cur = nxt; 900 } 901 } 902 // Since we may have deleted a from_card_cache entry from the RS, clear 903 // the FCC. 904 clear_fcc(); 905 } 906 907 908 size_t OtherRegionsTable::occupied() const { 909 // Cast away const in this case. 910 MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag); 911 size_t sum = occ_fine(); 912 sum += occ_sparse(); 913 sum += occ_coarse(); 914 return sum; 915 } 916 917 size_t OtherRegionsTable::occ_fine() const { 918 size_t sum = 0; 919 for (size_t i = 0; i < _max_fine_entries; i++) { 920 PosParPRT* cur = _fine_grain_regions[i]; 921 while (cur != NULL) { 922 sum += cur->occupied(); 923 cur = cur->next(); 924 } 925 } 926 return sum; 927 } 928 929 size_t OtherRegionsTable::occ_coarse() const { 930 return (_n_coarse_entries * HeapRegion::CardsPerRegion); 931 } 932 933 size_t OtherRegionsTable::occ_sparse() const { 934 return _sparse_table.occupied(); 935 } 936 937 size_t OtherRegionsTable::mem_size() const { 938 // Cast away const in this case. 939 MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag); 940 size_t sum = 0; 941 for (size_t i = 0; i < _max_fine_entries; i++) { 942 PosParPRT* cur = _fine_grain_regions[i]; 943 while (cur != NULL) { 944 sum += cur->mem_size(); 945 cur = cur->next(); 946 } 947 } 948 sum += (sizeof(PosParPRT*) * _max_fine_entries); 949 sum += (_coarse_map.size_in_words() * HeapWordSize); 950 sum += (_sparse_table.mem_size()); 951 sum += sizeof(*this) - sizeof(_sparse_table); // Avoid double counting above. 952 return sum; 953 } 954 955 size_t OtherRegionsTable::static_mem_size() { 956 return _from_card_cache_mem_size; 957 } 958 959 size_t OtherRegionsTable::fl_mem_size() { 960 return PerRegionTable::fl_mem_size() + PosParPRT::fl_mem_size(); 961 } 962 963 void OtherRegionsTable::clear_fcc() { 964 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 965 _from_card_cache[i][hr()->hrs_index()] = -1; 966 } 967 } 968 969 void OtherRegionsTable::clear() { 970 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 971 for (size_t i = 0; i < _max_fine_entries; i++) { 972 PosParPRT* cur = _fine_grain_regions[i]; 973 while (cur != NULL) { 974 PosParPRT* nxt = cur->next(); 975 PosParPRT::free(cur); 976 cur = nxt; 977 } 978 _fine_grain_regions[i] = NULL; 979 } 980 _sparse_table.clear(); 981 _coarse_map.clear(); 982 _n_fine_entries = 0; 983 _n_coarse_entries = 0; 984 985 clear_fcc(); 986 } 987 988 void OtherRegionsTable::clear_incoming_entry(HeapRegion* from_hr) { 989 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 990 size_t hrs_ind = (size_t)from_hr->hrs_index(); 991 size_t ind = hrs_ind & _mod_max_fine_entries_mask; 992 if (del_single_region_table(ind, from_hr)) { 993 assert(!_coarse_map.at(hrs_ind), "Inv"); 994 } else { 995 _coarse_map.par_at_put(hrs_ind, 0); 996 } 997 // Check to see if any of the fcc entries come from here. 998 int hr_ind = hr()->hrs_index(); 999 for (int tid = 0; tid < HeapRegionRemSet::num_par_rem_sets(); tid++) { 1000 int fcc_ent = _from_card_cache[tid][hr_ind]; 1001 if (fcc_ent != -1) { 1002 HeapWord* card_addr = (HeapWord*) 1003 (uintptr_t(fcc_ent) << CardTableModRefBS::card_shift); 1004 if (hr()->is_in_reserved(card_addr)) { 1005 // Clear the from card cache. 1006 _from_card_cache[tid][hr_ind] = -1; 1007 } 1008 } 1009 } 1010 } 1011 1012 bool OtherRegionsTable::del_single_region_table(size_t ind, 1013 HeapRegion* hr) { 1014 assert(0 <= ind && ind < _max_fine_entries, "Preconditions."); 1015 PosParPRT** prev_addr = &_fine_grain_regions[ind]; 1016 PosParPRT* prt = *prev_addr; 1017 while (prt != NULL && prt->hr() != hr) { 1018 prev_addr = prt->next_addr(); 1019 prt = prt->next(); 1020 } 1021 if (prt != NULL) { 1022 assert(prt->hr() == hr, "Loop postcondition."); 1023 *prev_addr = prt->next(); 1024 PosParPRT::free(prt); 1025 _n_fine_entries--; 1026 return true; 1027 } else { 1028 return false; 1029 } 1030 } 1031 1032 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const { 1033 // Cast away const in this case. 1034 MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag); 1035 return contains_reference_locked(from); 1036 } 1037 1038 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const { 1039 HeapRegion* hr = _g1h->heap_region_containing_raw(from); 1040 if (hr == NULL) return false; 1041 RegionIdx_t hr_ind = (RegionIdx_t) hr->hrs_index(); 1042 // Is this region in the coarse map? 1043 if (_coarse_map.at(hr_ind)) return true; 1044 1045 PosParPRT* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask, 1046 hr); 1047 if (prt != NULL) { 1048 return prt->contains_reference(from); 1049 1050 } else { 1051 uintptr_t from_card = 1052 (uintptr_t(from) >> CardTableModRefBS::card_shift); 1053 uintptr_t hr_bot_card_index = 1054 uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift; 1055 assert(from_card >= hr_bot_card_index, "Inv"); 1056 CardIdx_t card_index = from_card - hr_bot_card_index; 1057 assert(0 <= card_index && card_index < HeapRegion::CardsPerRegion, 1058 "Must be in range."); 1059 return _sparse_table.contains_card(hr_ind, card_index); 1060 } 1061 1062 1063 } 1064 1065 // Determines how many threads can add records to an rset in parallel. 1066 // This can be done by either mutator threads together with the 1067 // concurrent refinement threads or GC threads. 1068 int HeapRegionRemSet::num_par_rem_sets() { 1069 return (int)MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), ParallelGCThreads); 1070 } 1071 1072 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa, 1073 HeapRegion* hr) 1074 : _bosa(bosa), _other_regions(hr), _iter_state(Unclaimed) { } 1075 1076 1077 void HeapRegionRemSet::setup_remset_size() { 1078 // Setup sparse and fine-grain tables sizes. 1079 // table_size = base * (log(region_size / 1M) + 1) 1080 int region_size_log_mb = MAX2((int)HeapRegion::LogOfHRGrainBytes - (int)LOG_M, 0); 1081 if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) { 1082 G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1); 1083 } 1084 if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) { 1085 G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1); 1086 } 1087 guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity"); 1088 } 1089 1090 void HeapRegionRemSet::init_for_par_iteration() { 1091 _iter_state = Unclaimed; 1092 } 1093 1094 bool HeapRegionRemSet::claim_iter() { 1095 if (_iter_state != Unclaimed) return false; 1096 jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed); 1097 return (res == Unclaimed); 1098 } 1099 1100 void HeapRegionRemSet::set_iter_complete() { 1101 _iter_state = Complete; 1102 } 1103 1104 bool HeapRegionRemSet::iter_is_complete() { 1105 return _iter_state == Complete; 1106 } 1107 1108 1109 void HeapRegionRemSet::init_iterator(HeapRegionRemSetIterator* iter) const { 1110 iter->initialize(this); 1111 } 1112 1113 #ifndef PRODUCT 1114 void HeapRegionRemSet::print() const { 1115 HeapRegionRemSetIterator iter; 1116 init_iterator(&iter); 1117 size_t card_index; 1118 while (iter.has_next(card_index)) { 1119 HeapWord* card_start = 1120 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index); 1121 gclog_or_tty->print_cr(" Card " PTR_FORMAT ".", card_start); 1122 } 1123 // XXX 1124 if (iter.n_yielded() != occupied()) { 1125 gclog_or_tty->print_cr("Yielded disagrees with occupied:"); 1126 gclog_or_tty->print_cr(" %6d yielded (%6d coarse, %6d fine).", 1127 iter.n_yielded(), 1128 iter.n_yielded_coarse(), iter.n_yielded_fine()); 1129 gclog_or_tty->print_cr(" %6d occ (%6d coarse, %6d fine).", 1130 occupied(), occ_coarse(), occ_fine()); 1131 } 1132 guarantee(iter.n_yielded() == occupied(), 1133 "We should have yielded all the represented cards."); 1134 } 1135 #endif 1136 1137 void HeapRegionRemSet::cleanup() { 1138 SparsePRT::cleanup_all(); 1139 } 1140 1141 void HeapRegionRemSet::par_cleanup() { 1142 PosParPRT::par_contract_all(); 1143 } 1144 1145 void HeapRegionRemSet::clear() { 1146 _other_regions.clear(); 1147 assert(occupied() == 0, "Should be clear."); 1148 } 1149 1150 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs, 1151 BitMap* region_bm, BitMap* card_bm) { 1152 _other_regions.scrub(ctbs, region_bm, card_bm); 1153 } 1154 1155 //-------------------- Iteration -------------------- 1156 1157 HeapRegionRemSetIterator:: 1158 HeapRegionRemSetIterator() : 1159 _hrrs(NULL), 1160 _g1h(G1CollectedHeap::heap()), 1161 _bosa(NULL), 1162 _sparse_iter(size_t(G1CollectedHeap::heap()->reserved_region().start()) 1163 >> CardTableModRefBS::card_shift) 1164 {} 1165 1166 void HeapRegionRemSetIterator::initialize(const HeapRegionRemSet* hrrs) { 1167 _hrrs = hrrs; 1168 _coarse_map = &_hrrs->_other_regions._coarse_map; 1169 _fine_grain_regions = _hrrs->_other_regions._fine_grain_regions; 1170 _bosa = _hrrs->bosa(); 1171 1172 _is = Sparse; 1173 // Set these values so that we increment to the first region. 1174 _coarse_cur_region_index = -1; 1175 _coarse_cur_region_cur_card = (HeapRegion::CardsPerRegion-1);; 1176 1177 _cur_region_cur_card = 0; 1178 1179 _fine_array_index = -1; 1180 _fine_cur_prt = NULL; 1181 1182 _n_yielded_coarse = 0; 1183 _n_yielded_fine = 0; 1184 _n_yielded_sparse = 0; 1185 1186 _sparse_iter.init(&hrrs->_other_regions._sparse_table); 1187 } 1188 1189 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) { 1190 if (_hrrs->_other_regions._n_coarse_entries == 0) return false; 1191 // Go to the next card. 1192 _coarse_cur_region_cur_card++; 1193 // Was the last the last card in the current region? 1194 if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) { 1195 // Yes: find the next region. This may leave _coarse_cur_region_index 1196 // Set to the last index, in which case there are no more coarse 1197 // regions. 1198 _coarse_cur_region_index = 1199 (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1); 1200 if ((size_t)_coarse_cur_region_index < _coarse_map->size()) { 1201 _coarse_cur_region_cur_card = 0; 1202 HeapWord* r_bot = 1203 _g1h->region_at(_coarse_cur_region_index)->bottom(); 1204 _cur_region_card_offset = _bosa->index_for(r_bot); 1205 } else { 1206 return false; 1207 } 1208 } 1209 // If we didn't return false above, then we can yield a card. 1210 card_index = _cur_region_card_offset + _coarse_cur_region_cur_card; 1211 return true; 1212 } 1213 1214 void HeapRegionRemSetIterator::fine_find_next_non_null_prt() { 1215 // Otherwise, find the next bucket list in the array. 1216 _fine_array_index++; 1217 while (_fine_array_index < (int) OtherRegionsTable::_max_fine_entries) { 1218 _fine_cur_prt = _fine_grain_regions[_fine_array_index]; 1219 if (_fine_cur_prt != NULL) return; 1220 else _fine_array_index++; 1221 } 1222 assert(_fine_cur_prt == NULL, "Loop post"); 1223 } 1224 1225 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) { 1226 if (fine_has_next()) { 1227 _cur_region_cur_card = 1228 _fine_cur_prt->_bm.get_next_one_offset(_cur_region_cur_card + 1); 1229 } 1230 while (!fine_has_next()) { 1231 if (_cur_region_cur_card == (size_t) HeapRegion::CardsPerRegion) { 1232 _cur_region_cur_card = 0; 1233 _fine_cur_prt = _fine_cur_prt->next(); 1234 } 1235 if (_fine_cur_prt == NULL) { 1236 fine_find_next_non_null_prt(); 1237 if (_fine_cur_prt == NULL) return false; 1238 } 1239 assert(_fine_cur_prt != NULL && _cur_region_cur_card == 0, 1240 "inv."); 1241 HeapWord* r_bot = 1242 _fine_cur_prt->hr()->bottom(); 1243 _cur_region_card_offset = _bosa->index_for(r_bot); 1244 _cur_region_cur_card = _fine_cur_prt->_bm.get_next_one_offset(0); 1245 } 1246 assert(fine_has_next(), "Or else we exited the loop via the return."); 1247 card_index = _cur_region_card_offset + _cur_region_cur_card; 1248 return true; 1249 } 1250 1251 bool HeapRegionRemSetIterator::fine_has_next() { 1252 return 1253 _fine_cur_prt != NULL && 1254 _cur_region_cur_card < (size_t) HeapRegion::CardsPerRegion; 1255 } 1256 1257 bool HeapRegionRemSetIterator::has_next(size_t& card_index) { 1258 switch (_is) { 1259 case Sparse: 1260 if (_sparse_iter.has_next(card_index)) { 1261 _n_yielded_sparse++; 1262 return true; 1263 } 1264 // Otherwise, deliberate fall-through 1265 _is = Fine; 1266 case Fine: 1267 if (fine_has_next(card_index)) { 1268 _n_yielded_fine++; 1269 return true; 1270 } 1271 // Otherwise, deliberate fall-through 1272 _is = Coarse; 1273 case Coarse: 1274 if (coarse_has_next(card_index)) { 1275 _n_yielded_coarse++; 1276 return true; 1277 } 1278 // Otherwise... 1279 break; 1280 } 1281 assert(ParallelGCThreads > 1 || 1282 n_yielded() == _hrrs->occupied(), 1283 "Should have yielded all the cards in the rem set " 1284 "(in the non-par case)."); 1285 return false; 1286 } 1287 1288 1289 1290 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL; 1291 HeapWord** HeapRegionRemSet::_recorded_cards = NULL; 1292 HeapRegion** HeapRegionRemSet::_recorded_regions = NULL; 1293 int HeapRegionRemSet::_n_recorded = 0; 1294 1295 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL; 1296 int* HeapRegionRemSet::_recorded_event_index = NULL; 1297 int HeapRegionRemSet::_n_recorded_events = 0; 1298 1299 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) { 1300 if (_recorded_oops == NULL) { 1301 assert(_n_recorded == 0 1302 && _recorded_cards == NULL 1303 && _recorded_regions == NULL, 1304 "Inv"); 1305 _recorded_oops = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded); 1306 _recorded_cards = NEW_C_HEAP_ARRAY(HeapWord*, MaxRecorded); 1307 _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*, MaxRecorded); 1308 } 1309 if (_n_recorded == MaxRecorded) { 1310 gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded); 1311 } else { 1312 _recorded_cards[_n_recorded] = 1313 (HeapWord*)align_size_down(uintptr_t(f), 1314 CardTableModRefBS::card_size); 1315 _recorded_oops[_n_recorded] = f; 1316 _recorded_regions[_n_recorded] = hr; 1317 _n_recorded++; 1318 } 1319 } 1320 1321 void HeapRegionRemSet::record_event(Event evnt) { 1322 if (!G1RecordHRRSEvents) return; 1323 1324 if (_recorded_events == NULL) { 1325 assert(_n_recorded_events == 0 1326 && _recorded_event_index == NULL, 1327 "Inv"); 1328 _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents); 1329 _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents); 1330 } 1331 if (_n_recorded_events == MaxRecordedEvents) { 1332 gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents); 1333 } else { 1334 _recorded_events[_n_recorded_events] = evnt; 1335 _recorded_event_index[_n_recorded_events] = _n_recorded; 1336 _n_recorded_events++; 1337 } 1338 } 1339 1340 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) { 1341 switch (evnt) { 1342 case Event_EvacStart: 1343 str->print("Evac Start"); 1344 break; 1345 case Event_EvacEnd: 1346 str->print("Evac End"); 1347 break; 1348 case Event_RSUpdateEnd: 1349 str->print("RS Update End"); 1350 break; 1351 } 1352 } 1353 1354 void HeapRegionRemSet::print_recorded() { 1355 int cur_evnt = 0; 1356 Event cur_evnt_kind; 1357 int cur_evnt_ind = 0; 1358 if (_n_recorded_events > 0) { 1359 cur_evnt_kind = _recorded_events[cur_evnt]; 1360 cur_evnt_ind = _recorded_event_index[cur_evnt]; 1361 } 1362 1363 for (int i = 0; i < _n_recorded; i++) { 1364 while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) { 1365 gclog_or_tty->print("Event: "); 1366 print_event(gclog_or_tty, cur_evnt_kind); 1367 gclog_or_tty->print_cr(""); 1368 cur_evnt++; 1369 if (cur_evnt < MaxRecordedEvents) { 1370 cur_evnt_kind = _recorded_events[cur_evnt]; 1371 cur_evnt_ind = _recorded_event_index[cur_evnt]; 1372 } 1373 } 1374 gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]" 1375 " for ref " PTR_FORMAT ".\n", 1376 _recorded_cards[i], _recorded_regions[i]->bottom(), 1377 _recorded_oops[i]); 1378 } 1379 } 1380 1381 #ifndef PRODUCT 1382 void HeapRegionRemSet::test() { 1383 os::sleep(Thread::current(), (jlong)5000, false); 1384 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 1385 1386 // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same 1387 // hash bucket. 1388 HeapRegion* hr0 = g1h->region_at(0); 1389 HeapRegion* hr1 = g1h->region_at(1); 1390 HeapRegion* hr2 = g1h->region_at(5); 1391 HeapRegion* hr3 = g1h->region_at(6); 1392 HeapRegion* hr4 = g1h->region_at(7); 1393 HeapRegion* hr5 = g1h->region_at(8); 1394 1395 HeapWord* hr1_start = hr1->bottom(); 1396 HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2; 1397 HeapWord* hr1_last = hr1->end() - 1; 1398 1399 HeapWord* hr2_start = hr2->bottom(); 1400 HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2; 1401 HeapWord* hr2_last = hr2->end() - 1; 1402 1403 HeapWord* hr3_start = hr3->bottom(); 1404 HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2; 1405 HeapWord* hr3_last = hr3->end() - 1; 1406 1407 HeapRegionRemSet* hrrs = hr0->rem_set(); 1408 1409 // Make three references from region 0x101... 1410 hrrs->add_reference((OopOrNarrowOopStar)hr1_start); 1411 hrrs->add_reference((OopOrNarrowOopStar)hr1_mid); 1412 hrrs->add_reference((OopOrNarrowOopStar)hr1_last); 1413 1414 hrrs->add_reference((OopOrNarrowOopStar)hr2_start); 1415 hrrs->add_reference((OopOrNarrowOopStar)hr2_mid); 1416 hrrs->add_reference((OopOrNarrowOopStar)hr2_last); 1417 1418 hrrs->add_reference((OopOrNarrowOopStar)hr3_start); 1419 hrrs->add_reference((OopOrNarrowOopStar)hr3_mid); 1420 hrrs->add_reference((OopOrNarrowOopStar)hr3_last); 1421 1422 // Now cause a coarsening. 1423 hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom()); 1424 hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom()); 1425 1426 // Now, does iteration yield these three? 1427 HeapRegionRemSetIterator iter; 1428 hrrs->init_iterator(&iter); 1429 size_t sum = 0; 1430 size_t card_index; 1431 while (iter.has_next(card_index)) { 1432 HeapWord* card_start = 1433 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index); 1434 gclog_or_tty->print_cr(" Card " PTR_FORMAT ".", card_start); 1435 sum++; 1436 } 1437 guarantee(sum == 11 - 3 + 2048, "Failure"); 1438 guarantee(sum == hrrs->occupied(), "Failure"); 1439 } 1440 #endif