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/concurrentG1RefineThread.hpp" 28 #include "gc/g1/g1BlockOffsetTable.inline.hpp" 29 #include "gc/g1/g1CollectedHeap.inline.hpp" 30 #include "gc/g1/g1CollectorPolicy.hpp" 31 #include "gc/g1/g1GCPhaseTimes.hpp" 32 #include "gc/g1/g1HotCardCache.hpp" 33 #include "gc/g1/g1OopClosures.inline.hpp" 34 #include "gc/g1/g1RemSet.inline.hpp" 35 #include "gc/g1/heapRegionManager.inline.hpp" 36 #include "gc/g1/heapRegionRemSet.hpp" 37 #include "memory/iterator.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "utilities/globalDefinitions.hpp" 40 #include "utilities/intHisto.hpp" 41 #include "utilities/stack.inline.hpp" 42 43 G1RemSet::G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs) 44 : _g1(g1), _conc_refine_cards(0), 45 _ct_bs(ct_bs), _g1p(_g1->g1_policy()), 46 _cg1r(g1->concurrent_g1_refine()), 47 _cset_rs_update_cl(NULL), 48 _prev_period_summary(), 49 _into_cset_dirty_card_queue_set(false) 50 { 51 _cset_rs_update_cl = NEW_C_HEAP_ARRAY(G1ParPushHeapRSClosure*, n_workers(), mtGC); 52 for (uint i = 0; i < n_workers(); i++) { 53 _cset_rs_update_cl[i] = NULL; 54 } 55 if (G1SummarizeRSetStats) { 56 _prev_period_summary.initialize(this); 57 } 58 // Initialize the card queue set used to hold cards containing 59 // references into the collection set. 60 _into_cset_dirty_card_queue_set.initialize(NULL, // Should never be called by the Java code 61 DirtyCardQ_CBL_mon, 62 DirtyCardQ_FL_lock, 63 -1, // never trigger processing 64 -1, // no limit on length 65 Shared_DirtyCardQ_lock, 66 &JavaThread::dirty_card_queue_set()); 67 } 68 69 G1RemSet::~G1RemSet() { 70 for (uint i = 0; i < n_workers(); i++) { 71 assert(_cset_rs_update_cl[i] == NULL, "it should be"); 72 } 73 FREE_C_HEAP_ARRAY(G1ParPushHeapRSClosure*, _cset_rs_update_cl); 74 } 75 76 class ScanRSClosure : public HeapRegionClosure { 77 size_t _cards_done, _cards; 78 G1CollectedHeap* _g1h; 79 80 G1ParPushHeapRSClosure* _oc; 81 CodeBlobClosure* _code_root_cl; 82 83 G1BlockOffsetSharedArray* _bot_shared; 84 G1SATBCardTableModRefBS *_ct_bs; 85 86 double _strong_code_root_scan_time_sec; 87 uint _worker_i; 88 size_t _block_size; 89 bool _try_claimed; 90 91 public: 92 ScanRSClosure(G1ParPushHeapRSClosure* oc, 93 CodeBlobClosure* code_root_cl, 94 uint worker_i) : 95 _oc(oc), 96 _code_root_cl(code_root_cl), 97 _strong_code_root_scan_time_sec(0.0), 98 _cards(0), 99 _cards_done(0), 100 _worker_i(worker_i), 101 _try_claimed(false) 102 { 103 _g1h = G1CollectedHeap::heap(); 104 _bot_shared = _g1h->bot_shared(); 105 _ct_bs = _g1h->g1_barrier_set(); 106 _block_size = MAX2<size_t>(G1RSetScanBlockSize, 1); 107 } 108 109 void set_try_claimed() { _try_claimed = true; } 110 111 void scanCard(size_t index, HeapRegion *r) { 112 // Stack allocate the DirtyCardToOopClosure instance 113 HeapRegionDCTOC cl(_g1h, r, _oc, 114 CardTableModRefBS::Precise); 115 116 // Set the "from" region in the closure. 117 _oc->set_region(r); 118 MemRegion card_region(_bot_shared->address_for_index(index), G1BlockOffsetSharedArray::N_words); 119 MemRegion pre_gc_allocated(r->bottom(), r->scan_top()); 120 MemRegion mr = pre_gc_allocated.intersection(card_region); 121 if (!mr.is_empty() && !_ct_bs->is_card_claimed(index)) { 122 // We make the card as "claimed" lazily (so races are possible 123 // but they're benign), which reduces the number of duplicate 124 // scans (the rsets of the regions in the cset can intersect). 125 _ct_bs->set_card_claimed(index); 126 _cards_done++; 127 cl.do_MemRegion(mr); 128 } 129 } 130 131 void printCard(HeapRegion* card_region, size_t card_index, 132 HeapWord* card_start) { 133 gclog_or_tty->print_cr("T %u Region [" PTR_FORMAT ", " PTR_FORMAT ") " 134 "RS names card " SIZE_FORMAT_HEX ": " 135 "[" PTR_FORMAT ", " PTR_FORMAT ")", 136 _worker_i, 137 p2i(card_region->bottom()), p2i(card_region->end()), 138 card_index, 139 p2i(card_start), p2i(card_start + G1BlockOffsetSharedArray::N_words)); 140 } 141 142 void scan_strong_code_roots(HeapRegion* r) { 143 double scan_start = os::elapsedTime(); 144 r->strong_code_roots_do(_code_root_cl); 145 _strong_code_root_scan_time_sec += (os::elapsedTime() - scan_start); 146 } 147 148 bool doHeapRegion(HeapRegion* r) { 149 assert(r->in_collection_set(), "should only be called on elements of CS."); 150 HeapRegionRemSet* hrrs = r->rem_set(); 151 if (hrrs->iter_is_complete()) return false; // All done. 152 if (!_try_claimed && !hrrs->claim_iter()) return false; 153 // If we ever free the collection set concurrently, we should also 154 // clear the card table concurrently therefore we won't need to 155 // add regions of the collection set to the dirty cards region. 156 _g1h->push_dirty_cards_region(r); 157 // If we didn't return above, then 158 // _try_claimed || r->claim_iter() 159 // is true: either we're supposed to work on claimed-but-not-complete 160 // regions, or we successfully claimed the region. 161 162 HeapRegionRemSetIterator iter(hrrs); 163 size_t card_index; 164 165 // We claim cards in block so as to reduce the contention. The block size is determined by 166 // the G1RSetScanBlockSize parameter. 167 size_t jump_to_card = hrrs->iter_claimed_next(_block_size); 168 for (size_t current_card = 0; iter.has_next(card_index); current_card++) { 169 if (current_card >= jump_to_card + _block_size) { 170 jump_to_card = hrrs->iter_claimed_next(_block_size); 171 } 172 if (current_card < jump_to_card) continue; 173 HeapWord* card_start = _g1h->bot_shared()->address_for_index(card_index); 174 #if 0 175 gclog_or_tty->print("Rem set iteration yielded card [" PTR_FORMAT ", " PTR_FORMAT ").\n", 176 card_start, card_start + CardTableModRefBS::card_size_in_words); 177 #endif 178 179 HeapRegion* card_region = _g1h->heap_region_containing(card_start); 180 _cards++; 181 182 if (!card_region->is_on_dirty_cards_region_list()) { 183 _g1h->push_dirty_cards_region(card_region); 184 } 185 186 // If the card is dirty, then we will scan it during updateRS. 187 if (!card_region->in_collection_set() && 188 !_ct_bs->is_card_dirty(card_index)) { 189 scanCard(card_index, card_region); 190 } 191 } 192 if (!_try_claimed) { 193 // Scan the strong code root list attached to the current region 194 scan_strong_code_roots(r); 195 196 hrrs->set_iter_complete(); 197 } 198 return false; 199 } 200 201 double strong_code_root_scan_time_sec() { 202 return _strong_code_root_scan_time_sec; 203 } 204 205 size_t cards_done() { return _cards_done;} 206 size_t cards_looked_up() { return _cards;} 207 }; 208 209 size_t G1RemSet::scanRS(G1ParPushHeapRSClosure* oc, 210 CodeBlobClosure* heap_region_codeblobs, 211 uint worker_i) { 212 double rs_time_start = os::elapsedTime(); 213 214 HeapRegion *startRegion = _g1->start_cset_region_for_worker(worker_i); 215 216 ScanRSClosure scanRScl(oc, heap_region_codeblobs, worker_i); 217 218 _g1->collection_set_iterate_from(startRegion, &scanRScl); 219 scanRScl.set_try_claimed(); 220 _g1->collection_set_iterate_from(startRegion, &scanRScl); 221 222 double scan_rs_time_sec = (os::elapsedTime() - rs_time_start) 223 - scanRScl.strong_code_root_scan_time_sec(); 224 225 _g1p->phase_times()->record_time_secs(G1GCPhaseTimes::ScanRS, worker_i, scan_rs_time_sec); 226 _g1p->phase_times()->record_time_secs(G1GCPhaseTimes::CodeRoots, worker_i, scanRScl.strong_code_root_scan_time_sec()); 227 228 return scanRScl.cards_done(); 229 } 230 231 // Closure used for updating RSets and recording references that 232 // point into the collection set. Only called during an 233 // evacuation pause. 234 235 class RefineRecordRefsIntoCSCardTableEntryClosure: public CardTableEntryClosure { 236 G1RemSet* _g1rs; 237 DirtyCardQueue* _into_cset_dcq; 238 public: 239 RefineRecordRefsIntoCSCardTableEntryClosure(G1CollectedHeap* g1h, 240 DirtyCardQueue* into_cset_dcq) : 241 _g1rs(g1h->g1_rem_set()), _into_cset_dcq(into_cset_dcq) 242 {} 243 244 bool do_card_ptr(jbyte* card_ptr, uint worker_i) { 245 // The only time we care about recording cards that 246 // contain references that point into the collection set 247 // is during RSet updating within an evacuation pause. 248 // In this case worker_i should be the id of a GC worker thread. 249 assert(SafepointSynchronize::is_at_safepoint(), "not during an evacuation pause"); 250 assert(worker_i < ParallelGCThreads, "should be a GC worker"); 251 252 if (_g1rs->refine_card(card_ptr, worker_i, true)) { 253 // 'card_ptr' contains references that point into the collection 254 // set. We need to record the card in the DCQS 255 // (_into_cset_dirty_card_queue_set) 256 // that's used for that purpose. 257 // 258 // Enqueue the card 259 _into_cset_dcq->enqueue(card_ptr); 260 } 261 return true; 262 } 263 }; 264 265 void G1RemSet::updateRS(DirtyCardQueue* into_cset_dcq, uint worker_i) { 266 RefineRecordRefsIntoCSCardTableEntryClosure into_cset_update_rs_cl(_g1, into_cset_dcq); 267 268 G1GCParPhaseTimesTracker x(_g1p->phase_times(), G1GCPhaseTimes::UpdateRS, worker_i); 269 { 270 // Apply the closure to the entries of the hot card cache. 271 G1GCParPhaseTimesTracker y(_g1p->phase_times(), G1GCPhaseTimes::ScanHCC, worker_i); 272 _g1->iterate_hcc_closure(&into_cset_update_rs_cl, worker_i); 273 } 274 // Apply the closure to all remaining log entries. 275 _g1->iterate_dirty_card_closure(&into_cset_update_rs_cl, worker_i); 276 } 277 278 void G1RemSet::cleanupHRRS() { 279 HeapRegionRemSet::cleanup(); 280 } 281 282 size_t G1RemSet::oops_into_collection_set_do(G1ParPushHeapRSClosure* oc, 283 CodeBlobClosure* heap_region_codeblobs, 284 uint worker_i) { 285 // We cache the value of 'oc' closure into the appropriate slot in the 286 // _cset_rs_update_cl for this worker 287 assert(worker_i < n_workers(), "sanity"); 288 _cset_rs_update_cl[worker_i] = oc; 289 290 // A DirtyCardQueue that is used to hold cards containing references 291 // that point into the collection set. This DCQ is associated with a 292 // special DirtyCardQueueSet (see g1CollectedHeap.hpp). Under normal 293 // circumstances (i.e. the pause successfully completes), these cards 294 // are just discarded (there's no need to update the RSets of regions 295 // that were in the collection set - after the pause these regions 296 // are wholly 'free' of live objects. In the event of an evacuation 297 // failure the cards/buffers in this queue set are passed to the 298 // DirtyCardQueueSet that is used to manage RSet updates 299 DirtyCardQueue into_cset_dcq(&_into_cset_dirty_card_queue_set); 300 301 updateRS(&into_cset_dcq, worker_i); 302 size_t cards_scanned = scanRS(oc, heap_region_codeblobs, worker_i); 303 304 // We now clear the cached values of _cset_rs_update_cl for this worker 305 _cset_rs_update_cl[worker_i] = NULL; 306 return cards_scanned; 307 } 308 309 void G1RemSet::prepare_for_oops_into_collection_set_do() { 310 cleanupHRRS(); 311 _g1->set_refine_cte_cl_concurrency(false); 312 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); 313 dcqs.concatenate_logs(); 314 } 315 316 void G1RemSet::cleanup_after_oops_into_collection_set_do() { 317 // Cleanup after copy 318 _g1->set_refine_cte_cl_concurrency(true); 319 // Set all cards back to clean. 320 _g1->cleanUpCardTable(); 321 322 DirtyCardQueueSet& into_cset_dcqs = _into_cset_dirty_card_queue_set; 323 int into_cset_n_buffers = into_cset_dcqs.completed_buffers_num(); 324 325 if (_g1->evacuation_failed()) { 326 double restore_remembered_set_start = os::elapsedTime(); 327 328 // Restore remembered sets for the regions pointing into the collection set. 329 // We just need to transfer the completed buffers from the DirtyCardQueueSet 330 // used to hold cards that contain references that point into the collection set 331 // to the DCQS used to hold the deferred RS updates. 332 _g1->dirty_card_queue_set().merge_bufferlists(&into_cset_dcqs); 333 _g1->g1_policy()->phase_times()->record_evac_fail_restore_remsets((os::elapsedTime() - restore_remembered_set_start) * 1000.0); 334 } 335 336 // Free any completed buffers in the DirtyCardQueueSet used to hold cards 337 // which contain references that point into the collection. 338 _into_cset_dirty_card_queue_set.clear(); 339 assert(_into_cset_dirty_card_queue_set.completed_buffers_num() == 0, 340 "all buffers should be freed"); 341 _into_cset_dirty_card_queue_set.clear_n_completed_buffers(); 342 } 343 344 class ScrubRSClosure: public HeapRegionClosure { 345 G1CollectedHeap* _g1h; 346 BitMap* _region_bm; 347 BitMap* _card_bm; 348 CardTableModRefBS* _ctbs; 349 public: 350 ScrubRSClosure(BitMap* region_bm, BitMap* card_bm) : 351 _g1h(G1CollectedHeap::heap()), 352 _region_bm(region_bm), _card_bm(card_bm), 353 _ctbs(_g1h->g1_barrier_set()) {} 354 355 bool doHeapRegion(HeapRegion* r) { 356 if (!r->is_continues_humongous()) { 357 r->rem_set()->scrub(_ctbs, _region_bm, _card_bm); 358 } 359 return false; 360 } 361 }; 362 363 void G1RemSet::scrub(BitMap* region_bm, BitMap* card_bm, uint worker_num, HeapRegionClaimer *hrclaimer) { 364 ScrubRSClosure scrub_cl(region_bm, card_bm); 365 _g1->heap_region_par_iterate(&scrub_cl, worker_num, hrclaimer); 366 } 367 368 G1TriggerClosure::G1TriggerClosure() : 369 _triggered(false) { } 370 371 G1InvokeIfNotTriggeredClosure::G1InvokeIfNotTriggeredClosure(G1TriggerClosure* t_cl, 372 OopClosure* oop_cl) : 373 _trigger_cl(t_cl), _oop_cl(oop_cl) { } 374 375 G1Mux2Closure::G1Mux2Closure(OopClosure *c1, OopClosure *c2) : 376 _c1(c1), _c2(c2) { } 377 378 G1UpdateRSOrPushRefOopClosure:: 379 G1UpdateRSOrPushRefOopClosure(G1CollectedHeap* g1h, 380 G1RemSet* rs, 381 G1ParPushHeapRSClosure* push_ref_cl, 382 bool record_refs_into_cset, 383 uint worker_i) : 384 _g1(g1h), _g1_rem_set(rs), _from(NULL), 385 _record_refs_into_cset(record_refs_into_cset), 386 _push_ref_cl(push_ref_cl), _worker_i(worker_i) { } 387 388 // Returns true if the given card contains references that point 389 // into the collection set, if we're checking for such references; 390 // false otherwise. 391 392 bool G1RemSet::refine_card(jbyte* card_ptr, uint worker_i, 393 bool check_for_refs_into_cset) { 394 assert(_g1->is_in_exact(_ct_bs->addr_for(card_ptr)), 395 "Card at " PTR_FORMAT " index " SIZE_FORMAT " representing heap at " PTR_FORMAT " (%u) must be in committed heap", 396 p2i(card_ptr), 397 _ct_bs->index_for(_ct_bs->addr_for(card_ptr)), 398 p2i(_ct_bs->addr_for(card_ptr)), 399 _g1->addr_to_region(_ct_bs->addr_for(card_ptr))); 400 401 // If the card is no longer dirty, nothing to do. 402 if (*card_ptr != CardTableModRefBS::dirty_card_val()) { 403 // No need to return that this card contains refs that point 404 // into the collection set. 405 return false; 406 } 407 408 // Construct the region representing the card. 409 HeapWord* start = _ct_bs->addr_for(card_ptr); 410 // And find the region containing it. 411 HeapRegion* r = _g1->heap_region_containing(start); 412 413 // Why do we have to check here whether a card is on a young region, 414 // given that we dirty young regions and, as a result, the 415 // post-barrier is supposed to filter them out and never to enqueue 416 // them? When we allocate a new region as the "allocation region" we 417 // actually dirty its cards after we release the lock, since card 418 // dirtying while holding the lock was a performance bottleneck. So, 419 // as a result, it is possible for other threads to actually 420 // allocate objects in the region (after the acquire the lock) 421 // before all the cards on the region are dirtied. This is unlikely, 422 // and it doesn't happen often, but it can happen. So, the extra 423 // check below filters out those cards. 424 if (r->is_young()) { 425 return false; 426 } 427 428 // While we are processing RSet buffers during the collection, we 429 // actually don't want to scan any cards on the collection set, 430 // since we don't want to update remembered sets with entries that 431 // point into the collection set, given that live objects from the 432 // collection set are about to move and such entries will be stale 433 // very soon. This change also deals with a reliability issue which 434 // involves scanning a card in the collection set and coming across 435 // an array that was being chunked and looking malformed. Note, 436 // however, that if evacuation fails, we have to scan any objects 437 // that were not moved and create any missing entries. 438 if (r->in_collection_set()) { 439 return false; 440 } 441 442 // The result from the hot card cache insert call is either: 443 // * pointer to the current card 444 // (implying that the current card is not 'hot'), 445 // * null 446 // (meaning we had inserted the card ptr into the "hot" card cache, 447 // which had some headroom), 448 // * a pointer to a "hot" card that was evicted from the "hot" cache. 449 // 450 451 G1HotCardCache* hot_card_cache = _cg1r->hot_card_cache(); 452 if (hot_card_cache->use_cache()) { 453 assert(!check_for_refs_into_cset, "sanity"); 454 assert(!SafepointSynchronize::is_at_safepoint(), "sanity"); 455 456 card_ptr = hot_card_cache->insert(card_ptr); 457 if (card_ptr == NULL) { 458 // There was no eviction. Nothing to do. 459 return false; 460 } 461 462 start = _ct_bs->addr_for(card_ptr); 463 r = _g1->heap_region_containing(start); 464 465 // Checking whether the region we got back from the cache 466 // is young here is inappropriate. The region could have been 467 // freed, reallocated and tagged as young while in the cache. 468 // Hence we could see its young type change at any time. 469 } 470 471 // Don't use addr_for(card_ptr + 1) which can ask for 472 // a card beyond the heap. This is not safe without a perm 473 // gen at the upper end of the heap. 474 HeapWord* end = start + CardTableModRefBS::card_size_in_words; 475 MemRegion dirtyRegion(start, end); 476 477 G1ParPushHeapRSClosure* oops_in_heap_closure = NULL; 478 if (check_for_refs_into_cset) { 479 // ConcurrentG1RefineThreads have worker numbers larger than what 480 // _cset_rs_update_cl[] is set up to handle. But those threads should 481 // only be active outside of a collection which means that when they 482 // reach here they should have check_for_refs_into_cset == false. 483 assert((size_t)worker_i < n_workers(), "index of worker larger than _cset_rs_update_cl[].length"); 484 oops_in_heap_closure = _cset_rs_update_cl[worker_i]; 485 } 486 G1UpdateRSOrPushRefOopClosure update_rs_oop_cl(_g1, 487 _g1->g1_rem_set(), 488 oops_in_heap_closure, 489 check_for_refs_into_cset, 490 worker_i); 491 update_rs_oop_cl.set_from(r); 492 493 G1TriggerClosure trigger_cl; 494 FilterIntoCSClosure into_cs_cl(NULL, _g1, &trigger_cl); 495 G1InvokeIfNotTriggeredClosure invoke_cl(&trigger_cl, &into_cs_cl); 496 G1Mux2Closure mux(&invoke_cl, &update_rs_oop_cl); 497 498 FilterOutOfRegionClosure filter_then_update_rs_oop_cl(r, 499 (check_for_refs_into_cset ? 500 (OopClosure*)&mux : 501 (OopClosure*)&update_rs_oop_cl)); 502 503 // The region for the current card may be a young region. The 504 // current card may have been a card that was evicted from the 505 // card cache. When the card was inserted into the cache, we had 506 // determined that its region was non-young. While in the cache, 507 // the region may have been freed during a cleanup pause, reallocated 508 // and tagged as young. 509 // 510 // We wish to filter out cards for such a region but the current 511 // thread, if we're running concurrently, may "see" the young type 512 // change at any time (so an earlier "is_young" check may pass or 513 // fail arbitrarily). We tell the iteration code to perform this 514 // filtering when it has been determined that there has been an actual 515 // allocation in this region and making it safe to check the young type. 516 bool filter_young = true; 517 518 HeapWord* stop_point = 519 r->oops_on_card_seq_iterate_careful(dirtyRegion, 520 &filter_then_update_rs_oop_cl, 521 filter_young, 522 card_ptr); 523 524 // If stop_point is non-null, then we encountered an unallocated region 525 // (perhaps the unfilled portion of a TLAB.) For now, we'll dirty the 526 // card and re-enqueue: if we put off the card until a GC pause, then the 527 // unallocated portion will be filled in. Alternatively, we might try 528 // the full complexity of the technique used in "regular" precleaning. 529 if (stop_point != NULL) { 530 // The card might have gotten re-dirtied and re-enqueued while we 531 // worked. (In fact, it's pretty likely.) 532 if (*card_ptr != CardTableModRefBS::dirty_card_val()) { 533 *card_ptr = CardTableModRefBS::dirty_card_val(); 534 MutexLockerEx x(Shared_DirtyCardQ_lock, 535 Mutex::_no_safepoint_check_flag); 536 DirtyCardQueue* sdcq = 537 JavaThread::dirty_card_queue_set().shared_dirty_card_queue(); 538 sdcq->enqueue(card_ptr); 539 } 540 } else { 541 _conc_refine_cards++; 542 } 543 544 // This gets set to true if the card being refined has 545 // references that point into the collection set. 546 bool has_refs_into_cset = trigger_cl.triggered(); 547 548 // We should only be detecting that the card contains references 549 // that point into the collection set if the current thread is 550 // a GC worker thread. 551 assert(!has_refs_into_cset || SafepointSynchronize::is_at_safepoint(), 552 "invalid result at non safepoint"); 553 554 return has_refs_into_cset; 555 } 556 557 void G1RemSet::print_periodic_summary_info(const char* header) { 558 G1RemSetSummary current; 559 current.initialize(this); 560 561 _prev_period_summary.subtract_from(¤t); 562 print_summary_info(&_prev_period_summary, header); 563 564 _prev_period_summary.set(¤t); 565 } 566 567 void G1RemSet::print_summary_info() { 568 G1RemSetSummary current; 569 current.initialize(this); 570 571 print_summary_info(¤t, " Cumulative RS summary"); 572 } 573 574 void G1RemSet::print_summary_info(G1RemSetSummary * summary, const char * header) { 575 assert(summary != NULL, "just checking"); 576 577 if (header != NULL) { 578 gclog_or_tty->print_cr("%s", header); 579 } 580 581 summary->print_on(gclog_or_tty); 582 } 583 584 void G1RemSet::prepare_for_verify() { 585 if (G1HRRSFlushLogBuffersOnVerify && 586 (VerifyBeforeGC || VerifyAfterGC) 587 && (!_g1->collector_state()->full_collection() || G1VerifyRSetsDuringFullGC)) { 588 cleanupHRRS(); 589 _g1->set_refine_cte_cl_concurrency(false); 590 if (SafepointSynchronize::is_at_safepoint()) { 591 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); 592 dcqs.concatenate_logs(); 593 } 594 595 G1HotCardCache* hot_card_cache = _cg1r->hot_card_cache(); 596 bool use_hot_card_cache = hot_card_cache->use_cache(); 597 hot_card_cache->set_use_cache(false); 598 599 DirtyCardQueue into_cset_dcq(&_into_cset_dirty_card_queue_set); 600 updateRS(&into_cset_dcq, 0); 601 _into_cset_dirty_card_queue_set.clear(); 602 603 hot_card_cache->set_use_cache(use_hot_card_cache); 604 assert(JavaThread::dirty_card_queue_set().completed_buffers_num() == 0, "All should be consumed"); 605 } 606 }