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 _g1->set_refine_cte_cl_concurrency(false);
311 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
312 dcqs.concatenate_logs();
313 }
314
315 void G1RemSet::cleanup_after_oops_into_collection_set_do() {
316 // Cleanup after copy
317 _g1->set_refine_cte_cl_concurrency(true);
318 // Set all cards back to clean.
319 _g1->cleanUpCardTable();
320
321 DirtyCardQueueSet& into_cset_dcqs = _into_cset_dirty_card_queue_set;
322 int into_cset_n_buffers = into_cset_dcqs.completed_buffers_num();
323
324 if (_g1->evacuation_failed()) {
325 double restore_remembered_set_start = os::elapsedTime();
326
327 // Restore remembered sets for the regions pointing into the collection set.
328 // We just need to transfer the completed buffers from the DirtyCardQueueSet
329 // used to hold cards that contain references that point into the collection set
330 // to the DCQS used to hold the deferred RS updates.
331 _g1->dirty_card_queue_set().merge_bufferlists(&into_cset_dcqs);
332 _g1->g1_policy()->phase_times()->record_evac_fail_restore_remsets((os::elapsedTime() - restore_remembered_set_start) * 1000.0);
333 }
334
335 // Free any completed buffers in the DirtyCardQueueSet used to hold cards
336 // which contain references that point into the collection.
337 _into_cset_dirty_card_queue_set.clear();
338 assert(_into_cset_dirty_card_queue_set.completed_buffers_num() == 0,
339 "all buffers should be freed");
340 _into_cset_dirty_card_queue_set.clear_n_completed_buffers();
341 }
342
343 class ScrubRSClosure: public HeapRegionClosure {
344 G1CollectedHeap* _g1h;
345 BitMap* _region_bm;
346 BitMap* _card_bm;
347 CardTableModRefBS* _ctbs;
348 public:
349 ScrubRSClosure(BitMap* region_bm, BitMap* card_bm) :
350 _g1h(G1CollectedHeap::heap()),
351 _region_bm(region_bm), _card_bm(card_bm),
352 _ctbs(_g1h->g1_barrier_set()) {}
353
354 bool doHeapRegion(HeapRegion* r) {
355 if (!r->is_continues_humongous()) {
356 r->rem_set()->scrub(_ctbs, _region_bm, _card_bm);
357 }
358 return false;
359 }
360 };
361
362 void G1RemSet::scrub(BitMap* region_bm, BitMap* card_bm, uint worker_num, HeapRegionClaimer *hrclaimer) {
363 ScrubRSClosure scrub_cl(region_bm, card_bm);
364 _g1->heap_region_par_iterate(&scrub_cl, worker_num, hrclaimer);
365 }
366
367 G1TriggerClosure::G1TriggerClosure() :
368 _triggered(false) { }
369
370 G1InvokeIfNotTriggeredClosure::G1InvokeIfNotTriggeredClosure(G1TriggerClosure* t_cl,
371 OopClosure* oop_cl) :
372 _trigger_cl(t_cl), _oop_cl(oop_cl) { }
373
374 G1Mux2Closure::G1Mux2Closure(OopClosure *c1, OopClosure *c2) :
375 _c1(c1), _c2(c2) { }
376
377 G1UpdateRSOrPushRefOopClosure::
378 G1UpdateRSOrPushRefOopClosure(G1CollectedHeap* g1h,
379 G1RemSet* rs,
380 G1ParPushHeapRSClosure* push_ref_cl,
381 bool record_refs_into_cset,
382 uint worker_i) :
383 _g1(g1h), _g1_rem_set(rs), _from(NULL),
384 _record_refs_into_cset(record_refs_into_cset),
385 _push_ref_cl(push_ref_cl), _worker_i(worker_i) { }
386
387 // Returns true if the given card contains references that point
388 // into the collection set, if we're checking for such references;
389 // false otherwise.
390
391 bool G1RemSet::refine_card(jbyte* card_ptr, uint worker_i,
392 bool check_for_refs_into_cset) {
393 assert(_g1->is_in_exact(_ct_bs->addr_for(card_ptr)),
394 "Card at " PTR_FORMAT " index " SIZE_FORMAT " representing heap at " PTR_FORMAT " (%u) must be in committed heap",
395 p2i(card_ptr),
396 _ct_bs->index_for(_ct_bs->addr_for(card_ptr)),
397 p2i(_ct_bs->addr_for(card_ptr)),
398 _g1->addr_to_region(_ct_bs->addr_for(card_ptr)));
399
400 // If the card is no longer dirty, nothing to do.
401 if (*card_ptr != CardTableModRefBS::dirty_card_val()) {
402 // No need to return that this card contains refs that point
403 // into the collection set.
404 return false;
405 }
406
407 // Construct the region representing the card.
408 HeapWord* start = _ct_bs->addr_for(card_ptr);
409 // And find the region containing it.
410 HeapRegion* r = _g1->heap_region_containing(start);
411
412 // Why do we have to check here whether a card is on a young region,
413 // given that we dirty young regions and, as a result, the
414 // post-barrier is supposed to filter them out and never to enqueue
415 // them? When we allocate a new region as the "allocation region" we
416 // actually dirty its cards after we release the lock, since card
417 // dirtying while holding the lock was a performance bottleneck. So,
418 // as a result, it is possible for other threads to actually
419 // allocate objects in the region (after the acquire the lock)
420 // before all the cards on the region are dirtied. This is unlikely,
421 // and it doesn't happen often, but it can happen. So, the extra
422 // check below filters out those cards.
423 if (r->is_young()) {
424 return false;
425 }
426
427 // While we are processing RSet buffers during the collection, we
428 // actually don't want to scan any cards on the collection set,
429 // since we don't want to update remembered sets with entries that
430 // point into the collection set, given that live objects from the
431 // collection set are about to move and such entries will be stale
432 // very soon. This change also deals with a reliability issue which
433 // involves scanning a card in the collection set and coming across
434 // an array that was being chunked and looking malformed. Note,
435 // however, that if evacuation fails, we have to scan any objects
436 // that were not moved and create any missing entries.
437 if (r->in_collection_set()) {
438 return false;
439 }
440
441 // The result from the hot card cache insert call is either:
442 // * pointer to the current card
443 // (implying that the current card is not 'hot'),
444 // * null
445 // (meaning we had inserted the card ptr into the "hot" card cache,
446 // which had some headroom),
447 // * a pointer to a "hot" card that was evicted from the "hot" cache.
448 //
449
450 G1HotCardCache* hot_card_cache = _cg1r->hot_card_cache();
451 if (hot_card_cache->use_cache()) {
452 assert(!check_for_refs_into_cset, "sanity");
453 assert(!SafepointSynchronize::is_at_safepoint(), "sanity");
454
455 card_ptr = hot_card_cache->insert(card_ptr);
456 if (card_ptr == NULL) {
457 // There was no eviction. Nothing to do.
458 return false;
459 }
460
461 start = _ct_bs->addr_for(card_ptr);
462 r = _g1->heap_region_containing(start);
463
464 // Checking whether the region we got back from the cache
465 // is young here is inappropriate. The region could have been
466 // freed, reallocated and tagged as young while in the cache.
467 // Hence we could see its young type change at any time.
468 }
469
470 // Don't use addr_for(card_ptr + 1) which can ask for
471 // a card beyond the heap. This is not safe without a perm
472 // gen at the upper end of the heap.
473 HeapWord* end = start + CardTableModRefBS::card_size_in_words;
474 MemRegion dirtyRegion(start, end);
475
476 G1ParPushHeapRSClosure* oops_in_heap_closure = NULL;
477 if (check_for_refs_into_cset) {
478 // ConcurrentG1RefineThreads have worker numbers larger than what
479 // _cset_rs_update_cl[] is set up to handle. But those threads should
480 // only be active outside of a collection which means that when they
481 // reach here they should have check_for_refs_into_cset == false.
482 assert((size_t)worker_i < n_workers(), "index of worker larger than _cset_rs_update_cl[].length");
483 oops_in_heap_closure = _cset_rs_update_cl[worker_i];
484 }
485 G1UpdateRSOrPushRefOopClosure update_rs_oop_cl(_g1,
486 _g1->g1_rem_set(),
487 oops_in_heap_closure,
488 check_for_refs_into_cset,
489 worker_i);
490 update_rs_oop_cl.set_from(r);
491
492 G1TriggerClosure trigger_cl;
493 FilterIntoCSClosure into_cs_cl(NULL, _g1, &trigger_cl);
494 G1InvokeIfNotTriggeredClosure invoke_cl(&trigger_cl, &into_cs_cl);
495 G1Mux2Closure mux(&invoke_cl, &update_rs_oop_cl);
496
497 FilterOutOfRegionClosure filter_then_update_rs_oop_cl(r,
498 (check_for_refs_into_cset ?
499 (OopClosure*)&mux :
500 (OopClosure*)&update_rs_oop_cl));
501
502 // The region for the current card may be a young region. The
503 // current card may have been a card that was evicted from the
504 // card cache. When the card was inserted into the cache, we had
505 // determined that its region was non-young. While in the cache,
506 // the region may have been freed during a cleanup pause, reallocated
507 // and tagged as young.
508 //
509 // We wish to filter out cards for such a region but the current
510 // thread, if we're running concurrently, may "see" the young type
511 // change at any time (so an earlier "is_young" check may pass or
512 // fail arbitrarily). We tell the iteration code to perform this
513 // filtering when it has been determined that there has been an actual
514 // allocation in this region and making it safe to check the young type.
515 bool filter_young = true;
516
517 HeapWord* stop_point =
518 r->oops_on_card_seq_iterate_careful(dirtyRegion,
519 &filter_then_update_rs_oop_cl,
520 filter_young,
521 card_ptr);
522
523 // If stop_point is non-null, then we encountered an unallocated region
524 // (perhaps the unfilled portion of a TLAB.) For now, we'll dirty the
525 // card and re-enqueue: if we put off the card until a GC pause, then the
526 // unallocated portion will be filled in. Alternatively, we might try
527 // the full complexity of the technique used in "regular" precleaning.
528 if (stop_point != NULL) {
529 // The card might have gotten re-dirtied and re-enqueued while we
530 // worked. (In fact, it's pretty likely.)
531 if (*card_ptr != CardTableModRefBS::dirty_card_val()) {
532 *card_ptr = CardTableModRefBS::dirty_card_val();
533 MutexLockerEx x(Shared_DirtyCardQ_lock,
534 Mutex::_no_safepoint_check_flag);
535 DirtyCardQueue* sdcq =
536 JavaThread::dirty_card_queue_set().shared_dirty_card_queue();
537 sdcq->enqueue(card_ptr);
538 }
539 } else {
540 _conc_refine_cards++;
541 }
542
543 // This gets set to true if the card being refined has
544 // references that point into the collection set.
545 bool has_refs_into_cset = trigger_cl.triggered();
546
547 // We should only be detecting that the card contains references
548 // that point into the collection set if the current thread is
549 // a GC worker thread.
550 assert(!has_refs_into_cset || SafepointSynchronize::is_at_safepoint(),
551 "invalid result at non safepoint");
552
553 return has_refs_into_cset;
554 }
555
556 void G1RemSet::print_periodic_summary_info(const char* header) {
557 G1RemSetSummary current;
558 current.initialize(this);
559
560 _prev_period_summary.subtract_from(¤t);
561 print_summary_info(&_prev_period_summary, header);
562
563 _prev_period_summary.set(¤t);
564 }
565
566 void G1RemSet::print_summary_info() {
567 G1RemSetSummary current;
568 current.initialize(this);
569
570 print_summary_info(¤t, " Cumulative RS summary");
571 }
572
573 void G1RemSet::print_summary_info(G1RemSetSummary * summary, const char * header) {
574 assert(summary != NULL, "just checking");
575
576 if (header != NULL) {
577 gclog_or_tty->print_cr("%s", header);
578 }
579
580 summary->print_on(gclog_or_tty);
581 }
582
583 void G1RemSet::prepare_for_verify() {
584 if (G1HRRSFlushLogBuffersOnVerify &&
585 (VerifyBeforeGC || VerifyAfterGC)
586 && (!_g1->collector_state()->full_collection() || G1VerifyRSetsDuringFullGC)) {
587 cleanupHRRS();
588 _g1->set_refine_cte_cl_concurrency(false);
589 if (SafepointSynchronize::is_at_safepoint()) {
590 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
591 dcqs.concatenate_logs();
592 }
593
594 G1HotCardCache* hot_card_cache = _cg1r->hot_card_cache();
595 bool use_hot_card_cache = hot_card_cache->use_cache();
596 hot_card_cache->set_use_cache(false);
597
598 DirtyCardQueue into_cset_dcq(&_into_cset_dirty_card_queue_set);
599 updateRS(&into_cset_dcq, 0);
600 _into_cset_dirty_card_queue_set.clear();
601
602 hot_card_cache->set_use_cache(use_hot_card_cache);
603 assert(JavaThread::dirty_card_queue_set().completed_buffers_num() == 0, "All should be consumed");
604 }
605 }