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