1 /* 2 * Copyright (c) 2001, 2015, 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/g1/concurrentG1Refine.hpp" 27 #include "gc/g1/g1BlockOffsetTable.inline.hpp" 28 #include "gc/g1/g1CollectedHeap.inline.hpp" 29 #include "gc/g1/heapRegionManager.inline.hpp" 30 #include "gc/g1/heapRegionRemSet.hpp" 31 #include "gc/shared/space.inline.hpp" 32 #include "memory/allocation.hpp" 33 #include "memory/padded.inline.hpp" 34 #include "oops/oop.inline.hpp" 35 #include "runtime/atomic.inline.hpp" 36 #include "utilities/bitMap.inline.hpp" 37 #include "utilities/globalDefinitions.hpp" 38 #include "utilities/growableArray.hpp" 39 40 class PerRegionTable: public CHeapObj<mtGC> { 41 friend class OtherRegionsTable; 42 friend class HeapRegionRemSetIterator; 43 44 HeapRegion* _hr; 45 BitMap _bm; 46 jint _occupied; 47 48 // next pointer for free/allocated 'all' list 49 PerRegionTable* _next; 50 51 // prev pointer for the allocated 'all' list 52 PerRegionTable* _prev; 53 54 // next pointer in collision list 55 PerRegionTable * _collision_list_next; 56 57 // Global free list of PRTs 58 static PerRegionTable* _free_list; 59 60 protected: 61 // We need access in order to union things into the base table. 62 BitMap* bm() { return &_bm; } 63 64 void recount_occupied() { 65 _occupied = (jint) bm()->count_one_bits(); 66 } 67 68 PerRegionTable(HeapRegion* hr) : 69 _hr(hr), 70 _occupied(0), 71 _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */), 72 _collision_list_next(NULL), _next(NULL), _prev(NULL) 73 {} 74 75 void add_card_work(CardIdx_t from_card, bool par) { 76 if (!_bm.at(from_card)) { 77 if (par) { 78 if (_bm.par_at_put(from_card, 1)) { 79 Atomic::inc(&_occupied); 80 } 81 } else { 82 _bm.at_put(from_card, 1); 83 _occupied++; 84 } 85 } 86 } 87 88 void add_reference_work(OopOrNarrowOopStar from, bool par) { 89 // Must make this robust in case "from" is not in "_hr", because of 90 // concurrency. 91 92 if (G1TraceHeapRegionRememberedSet) { 93 gclog_or_tty->print_cr(" PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").", 94 p2i(from), 95 UseCompressedOops 96 ? p2i(oopDesc::load_decode_heap_oop((narrowOop*)from)) 97 : p2i(oopDesc::load_decode_heap_oop((oop*)from))); 98 } 99 100 HeapRegion* loc_hr = hr(); 101 // If the test below fails, then this table was reused concurrently 102 // with this operation. This is OK, since the old table was coarsened, 103 // and adding a bit to the new table is never incorrect. 104 // If the table used to belong to a continues humongous region and is 105 // now reused for the corresponding start humongous region, we need to 106 // make sure that we detect this. Thus, we call is_in_reserved_raw() 107 // instead of just is_in_reserved() here. 108 if (loc_hr->is_in_reserved_raw(from)) { 109 size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom()); 110 CardIdx_t from_card = (CardIdx_t) 111 hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize); 112 113 assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion, 114 "Must be in range."); 115 add_card_work(from_card, par); 116 } 117 } 118 119 public: 120 121 HeapRegion* hr() const { return _hr; } 122 123 jint occupied() const { 124 // Overkill, but if we ever need it... 125 // guarantee(_occupied == _bm.count_one_bits(), "Check"); 126 return _occupied; 127 } 128 129 void init(HeapRegion* hr, bool clear_links_to_all_list) { 130 if (clear_links_to_all_list) { 131 set_next(NULL); 132 set_prev(NULL); 133 } 134 _hr = hr; 135 _collision_list_next = NULL; 136 _occupied = 0; 137 _bm.clear(); 138 } 139 140 void add_reference(OopOrNarrowOopStar from) { 141 add_reference_work(from, /*parallel*/ true); 142 } 143 144 void seq_add_reference(OopOrNarrowOopStar from) { 145 add_reference_work(from, /*parallel*/ false); 146 } 147 148 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) { 149 HeapWord* hr_bot = hr()->bottom(); 150 size_t hr_first_card_index = ctbs->index_for(hr_bot); 151 bm()->set_intersection_at_offset(*card_bm, hr_first_card_index); 152 recount_occupied(); 153 } 154 155 void add_card(CardIdx_t from_card_index) { 156 add_card_work(from_card_index, /*parallel*/ true); 157 } 158 159 void seq_add_card(CardIdx_t from_card_index) { 160 add_card_work(from_card_index, /*parallel*/ false); 161 } 162 163 // (Destructively) union the bitmap of the current table into the given 164 // bitmap (which is assumed to be of the same size.) 165 void union_bitmap_into(BitMap* bm) { 166 bm->set_union(_bm); 167 } 168 169 // Mem size in bytes. 170 size_t mem_size() const { 171 return sizeof(PerRegionTable) + _bm.size_in_words() * HeapWordSize; 172 } 173 174 // Requires "from" to be in "hr()". 175 bool contains_reference(OopOrNarrowOopStar from) const { 176 assert(hr()->is_in_reserved(from), "Precondition."); 177 size_t card_ind = pointer_delta(from, hr()->bottom(), 178 CardTableModRefBS::card_size); 179 return _bm.at(card_ind); 180 } 181 182 // Bulk-free the PRTs from prt to last, assumes that they are 183 // linked together using their _next field. 184 static void bulk_free(PerRegionTable* prt, PerRegionTable* last) { 185 while (true) { 186 PerRegionTable* fl = _free_list; 187 last->set_next(fl); 188 PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl); 189 if (res == fl) { 190 return; 191 } 192 } 193 ShouldNotReachHere(); 194 } 195 196 static void free(PerRegionTable* prt) { 197 bulk_free(prt, prt); 198 } 199 200 // Returns an initialized PerRegionTable instance. 201 static PerRegionTable* alloc(HeapRegion* hr) { 202 PerRegionTable* fl = _free_list; 203 while (fl != NULL) { 204 PerRegionTable* nxt = fl->next(); 205 PerRegionTable* res = 206 (PerRegionTable*) 207 Atomic::cmpxchg_ptr(nxt, &_free_list, fl); 208 if (res == fl) { 209 fl->init(hr, true); 210 return fl; 211 } else { 212 fl = _free_list; 213 } 214 } 215 assert(fl == NULL, "Loop condition."); 216 return new PerRegionTable(hr); 217 } 218 219 PerRegionTable* next() const { return _next; } 220 void set_next(PerRegionTable* next) { _next = next; } 221 PerRegionTable* prev() const { return _prev; } 222 void set_prev(PerRegionTable* prev) { _prev = prev; } 223 224 // Accessor and Modification routines for the pointer for the 225 // singly linked collision list that links the PRTs within the 226 // OtherRegionsTable::_fine_grain_regions hash table. 227 // 228 // It might be useful to also make the collision list doubly linked 229 // to avoid iteration over the collisions list during scrubbing/deletion. 230 // OTOH there might not be many collisions. 231 232 PerRegionTable* collision_list_next() const { 233 return _collision_list_next; 234 } 235 236 void set_collision_list_next(PerRegionTable* next) { 237 _collision_list_next = next; 238 } 239 240 PerRegionTable** collision_list_next_addr() { 241 return &_collision_list_next; 242 } 243 244 static size_t fl_mem_size() { 245 PerRegionTable* cur = _free_list; 246 size_t res = 0; 247 while (cur != NULL) { 248 res += cur->mem_size(); 249 cur = cur->next(); 250 } 251 return res; 252 } 253 254 static void test_fl_mem_size(); 255 }; 256 257 PerRegionTable* PerRegionTable::_free_list = NULL; 258 259 size_t OtherRegionsTable::_max_fine_entries = 0; 260 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0; 261 size_t OtherRegionsTable::_fine_eviction_stride = 0; 262 size_t OtherRegionsTable::_fine_eviction_sample_size = 0; 263 264 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) : 265 _g1h(G1CollectedHeap::heap()), 266 _hr(hr), _m(m), 267 _coarse_map(G1CollectedHeap::heap()->max_regions(), 268 false /* in-resource-area */), 269 _fine_grain_regions(NULL), 270 _first_all_fine_prts(NULL), _last_all_fine_prts(NULL), 271 _n_fine_entries(0), _n_coarse_entries(0), 272 _fine_eviction_start(0), 273 _sparse_table(hr) 274 { 275 typedef PerRegionTable* PerRegionTablePtr; 276 277 if (_max_fine_entries == 0) { 278 assert(_mod_max_fine_entries_mask == 0, "Both or none."); 279 size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries); 280 _max_fine_entries = (size_t)1 << max_entries_log; 281 _mod_max_fine_entries_mask = _max_fine_entries - 1; 282 283 assert(_fine_eviction_sample_size == 0 284 && _fine_eviction_stride == 0, "All init at same time."); 285 _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log); 286 _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size; 287 } 288 289 _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries, 290 mtGC, CURRENT_PC, AllocFailStrategy::RETURN_NULL); 291 292 if (_fine_grain_regions == NULL) { 293 vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR, 294 "Failed to allocate _fine_grain_entries."); 295 } 296 297 for (size_t i = 0; i < _max_fine_entries; i++) { 298 _fine_grain_regions[i] = NULL; 299 } 300 } 301 302 void OtherRegionsTable::link_to_all(PerRegionTable* prt) { 303 // We always append to the beginning of the list for convenience; 304 // the order of entries in this list does not matter. 305 if (_first_all_fine_prts != NULL) { 306 assert(_first_all_fine_prts->prev() == NULL, "invariant"); 307 _first_all_fine_prts->set_prev(prt); 308 prt->set_next(_first_all_fine_prts); 309 } else { 310 // this is the first element we insert. Adjust the "last" pointer 311 _last_all_fine_prts = prt; 312 assert(prt->next() == NULL, "just checking"); 313 } 314 // the new element is always the first element without a predecessor 315 prt->set_prev(NULL); 316 _first_all_fine_prts = prt; 317 318 assert(prt->prev() == NULL, "just checking"); 319 assert(_first_all_fine_prts == prt, "just checking"); 320 assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) || 321 (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL), 322 "just checking"); 323 assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL, 324 "just checking"); 325 assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL, 326 "just checking"); 327 } 328 329 void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) { 330 if (prt->prev() != NULL) { 331 assert(_first_all_fine_prts != prt, "just checking"); 332 prt->prev()->set_next(prt->next()); 333 // removing the last element in the list? 334 if (_last_all_fine_prts == prt) { 335 _last_all_fine_prts = prt->prev(); 336 } 337 } else { 338 assert(_first_all_fine_prts == prt, "just checking"); 339 _first_all_fine_prts = prt->next(); 340 // list is empty now? 341 if (_first_all_fine_prts == NULL) { 342 _last_all_fine_prts = NULL; 343 } 344 } 345 346 if (prt->next() != NULL) { 347 prt->next()->set_prev(prt->prev()); 348 } 349 350 prt->set_next(NULL); 351 prt->set_prev(NULL); 352 353 assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) || 354 (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL), 355 "just checking"); 356 assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL, 357 "just checking"); 358 assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL, 359 "just checking"); 360 } 361 362 int** FromCardCache::_cache = NULL; 363 uint FromCardCache::_max_regions = 0; 364 size_t FromCardCache::_static_mem_size = 0; 365 366 void FromCardCache::initialize(uint n_par_rs, uint max_num_regions) { 367 guarantee(_cache == NULL, "Should not call this multiple times"); 368 369 _max_regions = max_num_regions; 370 _cache = Padded2DArray<int, mtGC>::create_unfreeable(n_par_rs, 371 _max_regions, 372 &_static_mem_size); 373 374 invalidate(0, _max_regions); 375 } 376 377 void FromCardCache::invalidate(uint start_idx, size_t new_num_regions) { 378 guarantee((size_t)start_idx + new_num_regions <= max_uintx, 379 err_msg("Trying to invalidate beyond maximum region, from %u size "SIZE_FORMAT, 380 start_idx, new_num_regions)); 381 for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 382 uint end_idx = (start_idx + (uint)new_num_regions); 383 assert(end_idx <= _max_regions, "Must be within max."); 384 for (uint j = start_idx; j < end_idx; j++) { 385 set(i, j, InvalidCard); 386 } 387 } 388 } 389 390 #ifndef PRODUCT 391 void FromCardCache::print(outputStream* out) { 392 for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 393 for (uint j = 0; j < _max_regions; j++) { 394 out->print_cr("_from_card_cache[%u][%u] = %d.", 395 i, j, at(i, j)); 396 } 397 } 398 } 399 #endif 400 401 void FromCardCache::clear(uint region_idx) { 402 uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets(); 403 for (uint i = 0; i < num_par_remsets; i++) { 404 set(i, region_idx, InvalidCard); 405 } 406 } 407 408 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, uint tid) { 409 uint cur_hrm_ind = _hr->hrm_index(); 410 411 if (G1TraceHeapRegionRememberedSet) { 412 gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").", 413 p2i(from), 414 UseCompressedOops 415 ? p2i(oopDesc::load_decode_heap_oop((narrowOop*)from)) 416 : p2i(oopDesc::load_decode_heap_oop((oop*)from))); 417 } 418 419 int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift); 420 421 if (G1TraceHeapRegionRememberedSet) { 422 gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)", 423 p2i(_hr->bottom()), from_card, 424 FromCardCache::at(tid, cur_hrm_ind)); 425 } 426 427 if (FromCardCache::contains_or_replace(tid, cur_hrm_ind, from_card)) { 428 if (G1TraceHeapRegionRememberedSet) { 429 gclog_or_tty->print_cr(" from-card cache hit."); 430 } 431 assert(contains_reference(from), "We just added it!"); 432 return; 433 } 434 435 // Note that this may be a continued H region. 436 HeapRegion* from_hr = _g1h->heap_region_containing_raw(from); 437 RegionIdx_t from_hrm_ind = (RegionIdx_t) from_hr->hrm_index(); 438 439 // If the region is already coarsened, return. 440 if (_coarse_map.at(from_hrm_ind)) { 441 if (G1TraceHeapRegionRememberedSet) { 442 gclog_or_tty->print_cr(" coarse map hit."); 443 } 444 assert(contains_reference(from), "We just added it!"); 445 return; 446 } 447 448 // Otherwise find a per-region table to add it to. 449 size_t ind = from_hrm_ind & _mod_max_fine_entries_mask; 450 PerRegionTable* prt = find_region_table(ind, from_hr); 451 if (prt == NULL) { 452 MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag); 453 // Confirm that it's really not there... 454 prt = find_region_table(ind, from_hr); 455 if (prt == NULL) { 456 457 uintptr_t from_hr_bot_card_index = 458 uintptr_t(from_hr->bottom()) 459 >> CardTableModRefBS::card_shift; 460 CardIdx_t card_index = from_card - from_hr_bot_card_index; 461 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion, 462 "Must be in range."); 463 if (G1HRRSUseSparseTable && 464 _sparse_table.add_card(from_hrm_ind, card_index)) { 465 if (G1RecordHRRSOops) { 466 HeapRegionRemSet::record(_hr, from); 467 if (G1TraceHeapRegionRememberedSet) { 468 gclog_or_tty->print(" Added card " PTR_FORMAT " to region " 469 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n", 470 align_size_down(uintptr_t(from), 471 CardTableModRefBS::card_size), 472 p2i(_hr->bottom()), p2i(from)); 473 } 474 } 475 if (G1TraceHeapRegionRememberedSet) { 476 gclog_or_tty->print_cr(" added card to sparse table."); 477 } 478 assert(contains_reference_locked(from), "We just added it!"); 479 return; 480 } else { 481 if (G1TraceHeapRegionRememberedSet) { 482 gclog_or_tty->print_cr(" [tid %u] sparse table entry " 483 "overflow(f: %d, t: %u)", 484 tid, from_hrm_ind, cur_hrm_ind); 485 } 486 } 487 488 if (_n_fine_entries == _max_fine_entries) { 489 prt = delete_region_table(); 490 // There is no need to clear the links to the 'all' list here: 491 // prt will be reused immediately, i.e. remain in the 'all' list. 492 prt->init(from_hr, false /* clear_links_to_all_list */); 493 } else { 494 prt = PerRegionTable::alloc(from_hr); 495 link_to_all(prt); 496 } 497 498 PerRegionTable* first_prt = _fine_grain_regions[ind]; 499 prt->set_collision_list_next(first_prt); 500 _fine_grain_regions[ind] = prt; 501 _n_fine_entries++; 502 503 if (G1HRRSUseSparseTable) { 504 // Transfer from sparse to fine-grain. 505 SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrm_ind); 506 assert(sprt_entry != NULL, "There should have been an entry"); 507 for (int i = 0; i < SparsePRTEntry::cards_num(); i++) { 508 CardIdx_t c = sprt_entry->card(i); 509 if (c != SparsePRTEntry::NullEntry) { 510 prt->add_card(c); 511 } 512 } 513 // Now we can delete the sparse entry. 514 bool res = _sparse_table.delete_entry(from_hrm_ind); 515 assert(res, "It should have been there."); 516 } 517 } 518 assert(prt != NULL && prt->hr() == from_hr, "consequence"); 519 } 520 // Note that we can't assert "prt->hr() == from_hr", because of the 521 // possibility of concurrent reuse. But see head comment of 522 // OtherRegionsTable for why this is OK. 523 assert(prt != NULL, "Inv"); 524 525 prt->add_reference(from); 526 527 if (G1RecordHRRSOops) { 528 HeapRegionRemSet::record(_hr, from); 529 if (G1TraceHeapRegionRememberedSet) { 530 gclog_or_tty->print("Added card " PTR_FORMAT " to region " 531 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n", 532 align_size_down(uintptr_t(from), 533 CardTableModRefBS::card_size), 534 p2i(_hr->bottom()), p2i(from)); 535 } 536 } 537 assert(contains_reference(from), "We just added it!"); 538 } 539 540 PerRegionTable* 541 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const { 542 assert(ind < _max_fine_entries, "Preconditions."); 543 PerRegionTable* prt = _fine_grain_regions[ind]; 544 while (prt != NULL && prt->hr() != hr) { 545 prt = prt->collision_list_next(); 546 } 547 // Loop postcondition is the method postcondition. 548 return prt; 549 } 550 551 jint OtherRegionsTable::_n_coarsenings = 0; 552 553 PerRegionTable* OtherRegionsTable::delete_region_table() { 554 assert(_m->owned_by_self(), "Precondition"); 555 assert(_n_fine_entries == _max_fine_entries, "Precondition"); 556 PerRegionTable* max = NULL; 557 jint max_occ = 0; 558 PerRegionTable** max_prev; 559 size_t max_ind; 560 561 size_t i = _fine_eviction_start; 562 for (size_t k = 0; k < _fine_eviction_sample_size; k++) { 563 size_t ii = i; 564 // Make sure we get a non-NULL sample. 565 while (_fine_grain_regions[ii] == NULL) { 566 ii++; 567 if (ii == _max_fine_entries) ii = 0; 568 guarantee(ii != i, "We must find one."); 569 } 570 PerRegionTable** prev = &_fine_grain_regions[ii]; 571 PerRegionTable* cur = *prev; 572 while (cur != NULL) { 573 jint cur_occ = cur->occupied(); 574 if (max == NULL || cur_occ > max_occ) { 575 max = cur; 576 max_prev = prev; 577 max_ind = i; 578 max_occ = cur_occ; 579 } 580 prev = cur->collision_list_next_addr(); 581 cur = cur->collision_list_next(); 582 } 583 i = i + _fine_eviction_stride; 584 if (i >= _n_fine_entries) i = i - _n_fine_entries; 585 } 586 587 _fine_eviction_start++; 588 589 if (_fine_eviction_start >= _n_fine_entries) { 590 _fine_eviction_start -= _n_fine_entries; 591 } 592 593 guarantee(max != NULL, "Since _n_fine_entries > 0"); 594 595 // Set the corresponding coarse bit. 596 size_t max_hrm_index = (size_t) max->hr()->hrm_index(); 597 if (!_coarse_map.at(max_hrm_index)) { 598 _coarse_map.at_put(max_hrm_index, true); 599 _n_coarse_entries++; 600 if (G1TraceHeapRegionRememberedSet) { 601 gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] " 602 "for region [" PTR_FORMAT "...] (" SIZE_FORMAT " coarse entries).\n", 603 p2i(_hr->bottom()), 604 p2i(max->hr()->bottom()), 605 _n_coarse_entries); 606 } 607 } 608 609 // Unsplice. 610 *max_prev = max->collision_list_next(); 611 Atomic::inc(&_n_coarsenings); 612 _n_fine_entries--; 613 return max; 614 } 615 616 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs, 617 BitMap* region_bm, BitMap* card_bm) { 618 // First eliminated garbage regions from the coarse map. 619 if (G1RSScrubVerbose) { 620 gclog_or_tty->print_cr("Scrubbing region %u:", _hr->hrm_index()); 621 } 622 623 assert(_coarse_map.size() == region_bm->size(), "Precondition"); 624 if (G1RSScrubVerbose) { 625 gclog_or_tty->print(" Coarse map: before = "SIZE_FORMAT"...", 626 _n_coarse_entries); 627 } 628 _coarse_map.set_intersection(*region_bm); 629 _n_coarse_entries = _coarse_map.count_one_bits(); 630 if (G1RSScrubVerbose) { 631 gclog_or_tty->print_cr(" after = "SIZE_FORMAT".", _n_coarse_entries); 632 } 633 634 // Now do the fine-grained maps. 635 for (size_t i = 0; i < _max_fine_entries; i++) { 636 PerRegionTable* cur = _fine_grain_regions[i]; 637 PerRegionTable** prev = &_fine_grain_regions[i]; 638 while (cur != NULL) { 639 PerRegionTable* nxt = cur->collision_list_next(); 640 // If the entire region is dead, eliminate. 641 if (G1RSScrubVerbose) { 642 gclog_or_tty->print_cr(" For other region %u:", 643 cur->hr()->hrm_index()); 644 } 645 if (!region_bm->at((size_t) cur->hr()->hrm_index())) { 646 *prev = nxt; 647 cur->set_collision_list_next(NULL); 648 _n_fine_entries--; 649 if (G1RSScrubVerbose) { 650 gclog_or_tty->print_cr(" deleted via region map."); 651 } 652 unlink_from_all(cur); 653 PerRegionTable::free(cur); 654 } else { 655 // Do fine-grain elimination. 656 if (G1RSScrubVerbose) { 657 gclog_or_tty->print(" occ: before = %4d.", cur->occupied()); 658 } 659 cur->scrub(ctbs, card_bm); 660 if (G1RSScrubVerbose) { 661 gclog_or_tty->print_cr(" after = %4d.", cur->occupied()); 662 } 663 // Did that empty the table completely? 664 if (cur->occupied() == 0) { 665 *prev = nxt; 666 cur->set_collision_list_next(NULL); 667 _n_fine_entries--; 668 unlink_from_all(cur); 669 PerRegionTable::free(cur); 670 } else { 671 prev = cur->collision_list_next_addr(); 672 } 673 } 674 cur = nxt; 675 } 676 } 677 // Since we may have deleted a from_card_cache entry from the RS, clear 678 // the FCC. 679 clear_fcc(); 680 } 681 682 bool OtherRegionsTable::occupancy_less_or_equal_than(size_t limit) const { 683 if (limit <= (size_t)G1RSetSparseRegionEntries) { 684 return occ_coarse() == 0 && _first_all_fine_prts == NULL && occ_sparse() <= limit; 685 } else { 686 // Current uses of this method may only use values less than G1RSetSparseRegionEntries 687 // for the limit. The solution, comparing against occupied() would be too slow 688 // at this time. 689 Unimplemented(); 690 return false; 691 } 692 } 693 694 bool OtherRegionsTable::is_empty() const { 695 return occ_sparse() == 0 && occ_coarse() == 0 && _first_all_fine_prts == NULL; 696 } 697 698 size_t OtherRegionsTable::occupied() const { 699 size_t sum = occ_fine(); 700 sum += occ_sparse(); 701 sum += occ_coarse(); 702 return sum; 703 } 704 705 size_t OtherRegionsTable::occ_fine() const { 706 size_t sum = 0; 707 708 size_t num = 0; 709 PerRegionTable * cur = _first_all_fine_prts; 710 while (cur != NULL) { 711 sum += cur->occupied(); 712 cur = cur->next(); 713 num++; 714 } 715 guarantee(num == _n_fine_entries, "just checking"); 716 return sum; 717 } 718 719 size_t OtherRegionsTable::occ_coarse() const { 720 return (_n_coarse_entries * HeapRegion::CardsPerRegion); 721 } 722 723 size_t OtherRegionsTable::occ_sparse() const { 724 return _sparse_table.occupied(); 725 } 726 727 size_t OtherRegionsTable::mem_size() const { 728 size_t sum = 0; 729 // all PRTs are of the same size so it is sufficient to query only one of them. 730 if (_first_all_fine_prts != NULL) { 731 assert(_last_all_fine_prts != NULL && 732 _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant"); 733 sum += _first_all_fine_prts->mem_size() * _n_fine_entries; 734 } 735 sum += (sizeof(PerRegionTable*) * _max_fine_entries); 736 sum += (_coarse_map.size_in_words() * HeapWordSize); 737 sum += (_sparse_table.mem_size()); 738 sum += sizeof(OtherRegionsTable) - sizeof(_sparse_table); // Avoid double counting above. 739 return sum; 740 } 741 742 size_t OtherRegionsTable::static_mem_size() { 743 return FromCardCache::static_mem_size(); 744 } 745 746 size_t OtherRegionsTable::fl_mem_size() { 747 return PerRegionTable::fl_mem_size(); 748 } 749 750 void OtherRegionsTable::clear_fcc() { 751 FromCardCache::clear(_hr->hrm_index()); 752 } 753 754 void OtherRegionsTable::clear() { 755 // if there are no entries, skip this step 756 if (_first_all_fine_prts != NULL) { 757 guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking"); 758 PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts); 759 memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0])); 760 } else { 761 guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking"); 762 } 763 764 _first_all_fine_prts = _last_all_fine_prts = NULL; 765 _sparse_table.clear(); 766 _coarse_map.clear(); 767 _n_fine_entries = 0; 768 _n_coarse_entries = 0; 769 770 clear_fcc(); 771 } 772 773 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const { 774 // Cast away const in this case. 775 MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag); 776 return contains_reference_locked(from); 777 } 778 779 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const { 780 HeapRegion* hr = _g1h->heap_region_containing_raw(from); 781 RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index(); 782 // Is this region in the coarse map? 783 if (_coarse_map.at(hr_ind)) return true; 784 785 PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask, 786 hr); 787 if (prt != NULL) { 788 return prt->contains_reference(from); 789 790 } else { 791 uintptr_t from_card = 792 (uintptr_t(from) >> CardTableModRefBS::card_shift); 793 uintptr_t hr_bot_card_index = 794 uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift; 795 assert(from_card >= hr_bot_card_index, "Inv"); 796 CardIdx_t card_index = from_card - hr_bot_card_index; 797 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion, 798 "Must be in range."); 799 return _sparse_table.contains_card(hr_ind, card_index); 800 } 801 } 802 803 void 804 OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) { 805 _sparse_table.do_cleanup_work(hrrs_cleanup_task); 806 } 807 808 // Determines how many threads can add records to an rset in parallel. 809 // This can be done by either mutator threads together with the 810 // concurrent refinement threads or GC threads. 811 uint HeapRegionRemSet::num_par_rem_sets() { 812 return MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), (uint)ParallelGCThreads); 813 } 814 815 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa, 816 HeapRegion* hr) 817 : _bosa(bosa), 818 _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true, Monitor::_safepoint_check_never), 819 _code_roots(), _other_regions(hr, &_m), _iter_state(Unclaimed), _iter_claimed(0) { 820 reset_for_par_iteration(); 821 } 822 823 void HeapRegionRemSet::setup_remset_size() { 824 // Setup sparse and fine-grain tables sizes. 825 // table_size = base * (log(region_size / 1M) + 1) 826 const int LOG_M = 20; 827 int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0); 828 if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) { 829 G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1); 830 } 831 if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) { 832 G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1); 833 } 834 guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity"); 835 } 836 837 bool HeapRegionRemSet::claim_iter() { 838 if (_iter_state != Unclaimed) return false; 839 jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed); 840 return (res == Unclaimed); 841 } 842 843 void HeapRegionRemSet::set_iter_complete() { 844 _iter_state = Complete; 845 } 846 847 bool HeapRegionRemSet::iter_is_complete() { 848 return _iter_state == Complete; 849 } 850 851 #ifndef PRODUCT 852 void HeapRegionRemSet::print() { 853 HeapRegionRemSetIterator iter(this); 854 size_t card_index; 855 while (iter.has_next(card_index)) { 856 HeapWord* card_start = 857 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index); 858 gclog_or_tty->print_cr(" Card " PTR_FORMAT, p2i(card_start)); 859 } 860 if (iter.n_yielded() != occupied()) { 861 gclog_or_tty->print_cr("Yielded disagrees with occupied:"); 862 gclog_or_tty->print_cr(" " SIZE_FORMAT_W(6) " yielded (" SIZE_FORMAT_W(6) 863 " coarse, " SIZE_FORMAT_W(6) " fine).", 864 iter.n_yielded(), 865 iter.n_yielded_coarse(), iter.n_yielded_fine()); 866 gclog_or_tty->print_cr(" " SIZE_FORMAT_W(6) " occ (" SIZE_FORMAT_W(6) 867 " coarse, " SIZE_FORMAT_W(6) " fine).", 868 occupied(), occ_coarse(), occ_fine()); 869 } 870 guarantee(iter.n_yielded() == occupied(), 871 "We should have yielded all the represented cards."); 872 } 873 #endif 874 875 void HeapRegionRemSet::cleanup() { 876 SparsePRT::cleanup_all(); 877 } 878 879 void HeapRegionRemSet::clear() { 880 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 881 clear_locked(); 882 } 883 884 void HeapRegionRemSet::clear_locked() { 885 _code_roots.clear(); 886 _other_regions.clear(); 887 assert(occupied_locked() == 0, "Should be clear."); 888 reset_for_par_iteration(); 889 } 890 891 void HeapRegionRemSet::reset_for_par_iteration() { 892 _iter_state = Unclaimed; 893 _iter_claimed = 0; 894 // It's good to check this to make sure that the two methods are in sync. 895 assert(verify_ready_for_par_iteration(), "post-condition"); 896 } 897 898 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs, 899 BitMap* region_bm, BitMap* card_bm) { 900 _other_regions.scrub(ctbs, region_bm, card_bm); 901 } 902 903 // Code roots support 904 // 905 // The code root set is protected by two separate locking schemes 906 // When at safepoint the per-hrrs lock must be held during modifications 907 // except when doing a full gc. 908 // When not at safepoint the CodeCache_lock must be held during modifications. 909 // When concurrent readers access the contains() function 910 // (during the evacuation phase) no removals are allowed. 911 912 void HeapRegionRemSet::add_strong_code_root(nmethod* nm) { 913 assert(nm != NULL, "sanity"); 914 // Optimistic unlocked contains-check 915 if (!_code_roots.contains(nm)) { 916 MutexLockerEx ml(&_m, Mutex::_no_safepoint_check_flag); 917 add_strong_code_root_locked(nm); 918 } 919 } 920 921 void HeapRegionRemSet::add_strong_code_root_locked(nmethod* nm) { 922 assert(nm != NULL, "sanity"); 923 _code_roots.add(nm); 924 } 925 926 void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) { 927 assert(nm != NULL, "sanity"); 928 assert_locked_or_safepoint(CodeCache_lock); 929 930 MutexLockerEx ml(CodeCache_lock->owned_by_self() ? NULL : &_m, Mutex::_no_safepoint_check_flag); 931 _code_roots.remove(nm); 932 933 // Check that there were no duplicates 934 guarantee(!_code_roots.contains(nm), "duplicate entry found"); 935 } 936 937 void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const { 938 _code_roots.nmethods_do(blk); 939 } 940 941 void HeapRegionRemSet::clean_strong_code_roots(HeapRegion* hr) { 942 _code_roots.clean(hr); 943 } 944 945 size_t HeapRegionRemSet::strong_code_roots_mem_size() { 946 return _code_roots.mem_size(); 947 } 948 949 HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) : 950 _hrrs(hrrs), 951 _g1h(G1CollectedHeap::heap()), 952 _coarse_map(&hrrs->_other_regions._coarse_map), 953 _bosa(hrrs->_bosa), 954 _is(Sparse), 955 // Set these values so that we increment to the first region. 956 _coarse_cur_region_index(-1), 957 _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1), 958 _cur_card_in_prt(HeapRegion::CardsPerRegion), 959 _fine_cur_prt(NULL), 960 _n_yielded_coarse(0), 961 _n_yielded_fine(0), 962 _n_yielded_sparse(0), 963 _sparse_iter(&hrrs->_other_regions._sparse_table) {} 964 965 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) { 966 if (_hrrs->_other_regions._n_coarse_entries == 0) return false; 967 // Go to the next card. 968 _coarse_cur_region_cur_card++; 969 // Was the last the last card in the current region? 970 if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) { 971 // Yes: find the next region. This may leave _coarse_cur_region_index 972 // Set to the last index, in which case there are no more coarse 973 // regions. 974 _coarse_cur_region_index = 975 (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1); 976 if ((size_t)_coarse_cur_region_index < _coarse_map->size()) { 977 _coarse_cur_region_cur_card = 0; 978 HeapWord* r_bot = 979 _g1h->region_at((uint) _coarse_cur_region_index)->bottom(); 980 _cur_region_card_offset = _bosa->index_for(r_bot); 981 } else { 982 return false; 983 } 984 } 985 // If we didn't return false above, then we can yield a card. 986 card_index = _cur_region_card_offset + _coarse_cur_region_cur_card; 987 return true; 988 } 989 990 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) { 991 if (fine_has_next()) { 992 _cur_card_in_prt = 993 _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1); 994 } 995 if (_cur_card_in_prt == HeapRegion::CardsPerRegion) { 996 // _fine_cur_prt may still be NULL in case if there are not PRTs at all for 997 // the remembered set. 998 if (_fine_cur_prt == NULL || _fine_cur_prt->next() == NULL) { 999 return false; 1000 } 1001 PerRegionTable* next_prt = _fine_cur_prt->next(); 1002 switch_to_prt(next_prt); 1003 _cur_card_in_prt = _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1); 1004 } 1005 1006 card_index = _cur_region_card_offset + _cur_card_in_prt; 1007 guarantee(_cur_card_in_prt < HeapRegion::CardsPerRegion, 1008 err_msg("Card index "SIZE_FORMAT" must be within the region", _cur_card_in_prt)); 1009 return true; 1010 } 1011 1012 bool HeapRegionRemSetIterator::fine_has_next() { 1013 return _cur_card_in_prt != HeapRegion::CardsPerRegion; 1014 } 1015 1016 void HeapRegionRemSetIterator::switch_to_prt(PerRegionTable* prt) { 1017 assert(prt != NULL, "Cannot switch to NULL prt"); 1018 _fine_cur_prt = prt; 1019 1020 HeapWord* r_bot = _fine_cur_prt->hr()->bottom(); 1021 _cur_region_card_offset = _bosa->index_for(r_bot); 1022 1023 // The bitmap scan for the PRT always scans from _cur_region_cur_card + 1. 1024 // To avoid special-casing this start case, and not miss the first bitmap 1025 // entry, initialize _cur_region_cur_card with -1 instead of 0. 1026 _cur_card_in_prt = (size_t)-1; 1027 } 1028 1029 bool HeapRegionRemSetIterator::has_next(size_t& card_index) { 1030 switch (_is) { 1031 case Sparse: { 1032 if (_sparse_iter.has_next(card_index)) { 1033 _n_yielded_sparse++; 1034 return true; 1035 } 1036 // Otherwise, deliberate fall-through 1037 _is = Fine; 1038 PerRegionTable* initial_fine_prt = _hrrs->_other_regions._first_all_fine_prts; 1039 if (initial_fine_prt != NULL) { 1040 switch_to_prt(_hrrs->_other_regions._first_all_fine_prts); 1041 } 1042 } 1043 case Fine: 1044 if (fine_has_next(card_index)) { 1045 _n_yielded_fine++; 1046 return true; 1047 } 1048 // Otherwise, deliberate fall-through 1049 _is = Coarse; 1050 case Coarse: 1051 if (coarse_has_next(card_index)) { 1052 _n_yielded_coarse++; 1053 return true; 1054 } 1055 // Otherwise... 1056 break; 1057 } 1058 assert(ParallelGCThreads > 1 || 1059 n_yielded() == _hrrs->occupied(), 1060 "Should have yielded all the cards in the rem set " 1061 "(in the non-par case)."); 1062 return false; 1063 } 1064 1065 1066 1067 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL; 1068 HeapWord** HeapRegionRemSet::_recorded_cards = NULL; 1069 HeapRegion** HeapRegionRemSet::_recorded_regions = NULL; 1070 int HeapRegionRemSet::_n_recorded = 0; 1071 1072 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL; 1073 int* HeapRegionRemSet::_recorded_event_index = NULL; 1074 int HeapRegionRemSet::_n_recorded_events = 0; 1075 1076 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) { 1077 if (_recorded_oops == NULL) { 1078 assert(_n_recorded == 0 1079 && _recorded_cards == NULL 1080 && _recorded_regions == NULL, 1081 "Inv"); 1082 _recorded_oops = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded, mtGC); 1083 _recorded_cards = NEW_C_HEAP_ARRAY(HeapWord*, MaxRecorded, mtGC); 1084 _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*, MaxRecorded, mtGC); 1085 } 1086 if (_n_recorded == MaxRecorded) { 1087 gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded); 1088 } else { 1089 _recorded_cards[_n_recorded] = 1090 (HeapWord*)align_size_down(uintptr_t(f), 1091 CardTableModRefBS::card_size); 1092 _recorded_oops[_n_recorded] = f; 1093 _recorded_regions[_n_recorded] = hr; 1094 _n_recorded++; 1095 } 1096 } 1097 1098 void HeapRegionRemSet::record_event(Event evnt) { 1099 if (!G1RecordHRRSEvents) return; 1100 1101 if (_recorded_events == NULL) { 1102 assert(_n_recorded_events == 0 1103 && _recorded_event_index == NULL, 1104 "Inv"); 1105 _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents, mtGC); 1106 _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents, mtGC); 1107 } 1108 if (_n_recorded_events == MaxRecordedEvents) { 1109 gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents); 1110 } else { 1111 _recorded_events[_n_recorded_events] = evnt; 1112 _recorded_event_index[_n_recorded_events] = _n_recorded; 1113 _n_recorded_events++; 1114 } 1115 } 1116 1117 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) { 1118 switch (evnt) { 1119 case Event_EvacStart: 1120 str->print("Evac Start"); 1121 break; 1122 case Event_EvacEnd: 1123 str->print("Evac End"); 1124 break; 1125 case Event_RSUpdateEnd: 1126 str->print("RS Update End"); 1127 break; 1128 } 1129 } 1130 1131 void HeapRegionRemSet::print_recorded() { 1132 int cur_evnt = 0; 1133 Event cur_evnt_kind; 1134 int cur_evnt_ind = 0; 1135 if (_n_recorded_events > 0) { 1136 cur_evnt_kind = _recorded_events[cur_evnt]; 1137 cur_evnt_ind = _recorded_event_index[cur_evnt]; 1138 } 1139 1140 for (int i = 0; i < _n_recorded; i++) { 1141 while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) { 1142 gclog_or_tty->print("Event: "); 1143 print_event(gclog_or_tty, cur_evnt_kind); 1144 gclog_or_tty->cr(); 1145 cur_evnt++; 1146 if (cur_evnt < MaxRecordedEvents) { 1147 cur_evnt_kind = _recorded_events[cur_evnt]; 1148 cur_evnt_ind = _recorded_event_index[cur_evnt]; 1149 } 1150 } 1151 gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]" 1152 " for ref " PTR_FORMAT ".\n", 1153 p2i(_recorded_cards[i]), p2i(_recorded_regions[i]->bottom()), 1154 p2i(_recorded_oops[i])); 1155 } 1156 } 1157 1158 void HeapRegionRemSet::reset_for_cleanup_tasks() { 1159 SparsePRT::reset_for_cleanup_tasks(); 1160 } 1161 1162 void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) { 1163 _other_regions.do_cleanup_work(hrrs_cleanup_task); 1164 } 1165 1166 void 1167 HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) { 1168 SparsePRT::finish_cleanup_task(hrrs_cleanup_task); 1169 } 1170 1171 #ifndef PRODUCT 1172 void PerRegionTable::test_fl_mem_size() { 1173 PerRegionTable* dummy = alloc(NULL); 1174 1175 size_t min_prt_size = sizeof(void*) + dummy->bm()->size_in_words() * HeapWordSize; 1176 assert(dummy->mem_size() > min_prt_size, 1177 err_msg("PerRegionTable memory usage is suspiciously small, only has "SIZE_FORMAT" bytes. " 1178 "Should be at least "SIZE_FORMAT" bytes.", dummy->mem_size(), min_prt_size)); 1179 free(dummy); 1180 guarantee(dummy->mem_size() == fl_mem_size(), "fl_mem_size() does not return the correct element size"); 1181 // try to reset the state 1182 _free_list = NULL; 1183 delete dummy; 1184 } 1185 1186 void HeapRegionRemSet::test_prt() { 1187 PerRegionTable::test_fl_mem_size(); 1188 } 1189 1190 void HeapRegionRemSet::test() { 1191 os::sleep(Thread::current(), (jlong)5000, false); 1192 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 1193 1194 // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same 1195 // hash bucket. 1196 HeapRegion* hr0 = g1h->region_at(0); 1197 HeapRegion* hr1 = g1h->region_at(1); 1198 HeapRegion* hr2 = g1h->region_at(5); 1199 HeapRegion* hr3 = g1h->region_at(6); 1200 HeapRegion* hr4 = g1h->region_at(7); 1201 HeapRegion* hr5 = g1h->region_at(8); 1202 1203 HeapWord* hr1_start = hr1->bottom(); 1204 HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2; 1205 HeapWord* hr1_last = hr1->end() - 1; 1206 1207 HeapWord* hr2_start = hr2->bottom(); 1208 HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2; 1209 HeapWord* hr2_last = hr2->end() - 1; 1210 1211 HeapWord* hr3_start = hr3->bottom(); 1212 HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2; 1213 HeapWord* hr3_last = hr3->end() - 1; 1214 1215 HeapRegionRemSet* hrrs = hr0->rem_set(); 1216 1217 // Make three references from region 0x101... 1218 hrrs->add_reference((OopOrNarrowOopStar)hr1_start); 1219 hrrs->add_reference((OopOrNarrowOopStar)hr1_mid); 1220 hrrs->add_reference((OopOrNarrowOopStar)hr1_last); 1221 1222 hrrs->add_reference((OopOrNarrowOopStar)hr2_start); 1223 hrrs->add_reference((OopOrNarrowOopStar)hr2_mid); 1224 hrrs->add_reference((OopOrNarrowOopStar)hr2_last); 1225 1226 hrrs->add_reference((OopOrNarrowOopStar)hr3_start); 1227 hrrs->add_reference((OopOrNarrowOopStar)hr3_mid); 1228 hrrs->add_reference((OopOrNarrowOopStar)hr3_last); 1229 1230 // Now cause a coarsening. 1231 hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom()); 1232 hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom()); 1233 1234 // Now, does iteration yield these three? 1235 HeapRegionRemSetIterator iter(hrrs); 1236 size_t sum = 0; 1237 size_t card_index; 1238 while (iter.has_next(card_index)) { 1239 HeapWord* card_start = 1240 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index); 1241 gclog_or_tty->print_cr(" Card " PTR_FORMAT ".", p2i(card_start)); 1242 sum++; 1243 } 1244 guarantee(sum == 11 - 3 + 2048, "Failure"); 1245 guarantee(sum == hrrs->occupied(), "Failure"); 1246 } 1247 #endif