1 /*
2 * Copyright (c) 2015, 2018, 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 #include "precompiled.hpp"
25 #include "gc/z/zBarrier.inline.hpp"
26 #include "gc/z/zMark.inline.hpp"
27 #include "gc/z/zMarkCache.inline.hpp"
28 #include "gc/z/zMarkStack.inline.hpp"
29 #include "gc/z/zMarkTerminate.inline.hpp"
30 #include "gc/z/zOopClosures.inline.hpp"
31 #include "gc/z/zPage.hpp"
32 #include "gc/z/zPageTable.inline.hpp"
33 #include "gc/z/zRootsIterator.hpp"
34 #include "gc/z/zStat.hpp"
35 #include "gc/z/zStatTLAB.hpp"
36 #include "gc/z/zTask.hpp"
37 #include "gc/z/zThread.hpp"
38 #include "gc/z/zUtils.inline.hpp"
39 #include "gc/z/zWorkers.inline.hpp"
40 #include "logging/log.hpp"
41 #include "memory/iterator.inline.hpp"
42 #include "oops/objArrayOop.inline.hpp"
43 #include "oops/oop.inline.hpp"
44 #include "runtime/atomic.hpp"
45 #include "runtime/handshake.hpp"
46 #include "runtime/orderAccess.hpp"
47 #include "runtime/prefetch.inline.hpp"
48 #include "runtime/thread.hpp"
49 #include "utilities/align.hpp"
50 #include "utilities/globalDefinitions.hpp"
51 #include "utilities/ticks.hpp"
52
53 static const ZStatSubPhase ZSubPhaseConcurrentMark("Concurrent Mark");
54 static const ZStatSubPhase ZSubPhaseConcurrentMarkTryFlush("Concurrent Mark Try Flush");
55 static const ZStatSubPhase ZSubPhaseConcurrentMarkIdle("Concurrent Mark Idle");
56 static const ZStatSubPhase ZSubPhaseConcurrentMarkTryTerminate("Concurrent Mark Try Terminate");
57 static const ZStatSubPhase ZSubPhaseMarkTryComplete("Pause Mark Try Complete");
58
59 ZMark::ZMark(ZWorkers* workers, ZPageTable* pagetable) :
60 _workers(workers),
61 _pagetable(pagetable),
62 _allocator(),
63 _stripes(),
64 _terminate(),
65 _work_terminateflush(true),
66 _work_nproactiveflush(0),
67 _work_nterminateflush(0),
68 _nproactiveflush(0),
69 _nterminateflush(0),
70 _ntrycomplete(0),
71 _ncontinue(0),
72 _nworkers(0) {}
73
74 bool ZMark::is_initialized() const {
75 return _allocator.is_initialized();
76 }
77
78 size_t ZMark::calculate_nstripes(uint nworkers) const {
79 // Calculate the number of stripes from the number of workers we use,
80 // where the number of stripes must be a power of two and we want to
81 // have at least one worker per stripe.
82 const size_t nstripes = ZUtils::round_down_power_of_2(nworkers);
83 return MIN2(nstripes, ZMarkStripesMax);
84 }
85
86 void ZMark::prepare_mark() {
87 // Increment global sequence number to invalidate
88 // marking information for all pages.
89 ZGlobalSeqNum++;
90
91 // Reset flush/continue counters
92 _nproactiveflush = 0;
93 _nterminateflush = 0;
94 _ntrycomplete = 0;
95 _ncontinue = 0;
96
97 // Set number of workers to use
98 _nworkers = _workers->nconcurrent();
99
100 // Set number of mark stripes to use, based on number
101 // of workers we will use in the concurrent mark phase.
102 const size_t nstripes = calculate_nstripes(_nworkers);
103 _stripes.set_nstripes(nstripes);
104
105 // Update statistics
106 ZStatMark::set_at_mark_start(nstripes);
107
108 // Print worker/stripe distribution
109 LogTarget(Debug, gc, marking) log;
110 if (log.is_enabled()) {
111 log.print("Mark Worker/Stripe Distribution");
112 for (uint worker_id = 0; worker_id < _nworkers; worker_id++) {
113 const ZMarkStripe* const stripe = _stripes.stripe_for_worker(_nworkers, worker_id);
114 const size_t stripe_id = _stripes.stripe_id(stripe);
115 log.print(" Worker %u(%u) -> Stripe " SIZE_FORMAT "(" SIZE_FORMAT ")",
116 worker_id, _nworkers, stripe_id, nstripes);
117 }
118 }
119 }
120
121 class ZMarkRootsIteratorClosure : public ZRootsIteratorClosure {
122 public:
123 ZMarkRootsIteratorClosure() {
124 ZStatTLAB::reset();
125 }
126
127 ~ZMarkRootsIteratorClosure() {
128 ZStatTLAB::publish();
129 }
130
131 virtual void do_thread(Thread* thread) {
132 ZRootsIteratorClosure::do_thread(thread);
133
134 // Update thread local address bad mask
135 ZThreadLocalData::set_address_bad_mask(thread, ZAddressBadMask);
136
137 // Retire TLAB
138 if (UseTLAB && thread->is_Java_thread()) {
139 thread->tlab().retire(ZStatTLAB::get());
140 thread->tlab().resize();
141 }
142 }
143
144 virtual void do_oop(oop* p) {
145 ZBarrier::mark_barrier_on_root_oop_field(p);
146 }
147
148 virtual void do_oop(narrowOop* p) {
149 ShouldNotReachHere();
150 }
151 };
152
153 class ZMarkRootsTask : public ZTask {
154 private:
155 ZMark* const _mark;
156 ZRootsIterator _roots;
157 ZMarkRootsIteratorClosure _cl;
158
159 public:
160 ZMarkRootsTask(ZMark* mark) :
161 ZTask("ZMarkRootsTask"),
162 _mark(mark),
163 _roots() {}
164
165 virtual void work() {
166 _roots.oops_do(&_cl);
167
168 // Flush and free worker stacks. Needed here since
169 // the set of workers executing during root scanning
170 // can be different from the set of workers executing
171 // during mark.
172 _mark->flush_and_free();
173 }
174 };
175
176 void ZMark::start() {
177 // Verification
178 if (ZVerifyMarking) {
179 verify_all_stacks_empty();
180 }
181
182 // Prepare for concurrent mark
183 prepare_mark();
184
185 // Mark roots
186 ZMarkRootsTask task(this);
187 _workers->run_parallel(&task);
188 }
189
190 void ZMark::prepare_work() {
191 assert(_nworkers == _workers->nconcurrent(), "Invalid number of workers");
192
193 // Set number of active workers
194 _terminate.reset(_nworkers);
195
196 // Reset flush counters
197 _work_nproactiveflush = _work_nterminateflush = 0;
198 _work_terminateflush = true;
199 }
200
201 void ZMark::finish_work() {
202 // Accumulate proactive/terminate flush counters
203 _nproactiveflush += _work_nproactiveflush;
204 _nterminateflush += _work_nterminateflush;
205 }
206
207 bool ZMark::is_array(uintptr_t addr) const {
208 return ZOop::to_oop(addr)->is_objArray();
209 }
210
211 void ZMark::push_partial_array(uintptr_t addr, size_t size, bool finalizable) {
212 assert(is_aligned(addr, ZMarkPartialArrayMinSize), "Address misaligned");
213 ZMarkThreadLocalStacks* const stacks = ZThreadLocalData::stacks(Thread::current());
214 ZMarkStripe* const stripe = _stripes.stripe_for_addr(addr);
215 const uintptr_t offset = ZAddress::offset(addr) >> ZMarkPartialArrayMinSizeShift;
216 const uintptr_t length = size / oopSize;
217 const ZMarkStackEntry entry(offset, length, finalizable);
218
219 log_develop_trace(gc, marking)("Array push partial: " PTR_FORMAT " (" SIZE_FORMAT "), stripe: " SIZE_FORMAT,
220 addr, size, _stripes.stripe_id(stripe));
221
222 stacks->push(&_allocator, &_stripes, stripe, entry, false /* publish */);
223 }
224
225 void ZMark::follow_small_array(uintptr_t addr, size_t size, bool finalizable) {
226 assert(size <= ZMarkPartialArrayMinSize, "Too large, should be split");
227 const size_t length = size / oopSize;
228
229 log_develop_trace(gc, marking)("Array follow small: " PTR_FORMAT " (" SIZE_FORMAT ")", addr, size);
230
231 ZBarrier::mark_barrier_on_oop_array((oop*)addr, length, finalizable);
232 }
233
234 void ZMark::follow_large_array(uintptr_t addr, size_t size, bool finalizable) {
235 assert(size <= (size_t)arrayOopDesc::max_array_length(T_OBJECT) * oopSize, "Too large");
236 assert(size > ZMarkPartialArrayMinSize, "Too small, should not be split");
237 const uintptr_t start = addr;
238 const uintptr_t end = start + size;
239
240 // Calculate the aligned middle start/end/size, where the middle start
241 // should always be greater than the start (hence the +1 below) to make
242 // sure we always do some follow work, not just split the array into pieces.
243 const uintptr_t middle_start = align_up(start + 1, ZMarkPartialArrayMinSize);
244 const size_t middle_size = align_down(end - middle_start, ZMarkPartialArrayMinSize);
245 const uintptr_t middle_end = middle_start + middle_size;
246
247 log_develop_trace(gc, marking)("Array follow large: " PTR_FORMAT "-" PTR_FORMAT" (" SIZE_FORMAT "), "
248 "middle: " PTR_FORMAT "-" PTR_FORMAT " (" SIZE_FORMAT ")",
249 start, end, size, middle_start, middle_end, middle_size);
250
251 // Push unaligned trailing part
252 if (end > middle_end) {
253 const uintptr_t trailing_addr = middle_end;
254 const size_t trailing_size = end - middle_end;
255 push_partial_array(trailing_addr, trailing_size, finalizable);
256 }
257
258 // Push aligned middle part(s)
259 uintptr_t partial_addr = middle_end;
260 while (partial_addr > middle_start) {
261 const size_t parts = 2;
262 const size_t partial_size = align_up((partial_addr - middle_start) / parts, ZMarkPartialArrayMinSize);
263 partial_addr -= partial_size;
264 push_partial_array(partial_addr, partial_size, finalizable);
265 }
266
267 // Follow leading part
268 assert(start < middle_start, "Miscalculated middle start");
269 const uintptr_t leading_addr = start;
270 const size_t leading_size = middle_start - start;
271 follow_small_array(leading_addr, leading_size, finalizable);
272 }
273
274 void ZMark::follow_array(uintptr_t addr, size_t size, bool finalizable) {
275 if (size <= ZMarkPartialArrayMinSize) {
276 follow_small_array(addr, size, finalizable);
277 } else {
278 follow_large_array(addr, size, finalizable);
279 }
280 }
281
282 void ZMark::follow_partial_array(ZMarkStackEntry entry, bool finalizable) {
283 const uintptr_t addr = ZAddress::good(entry.partial_array_offset() << ZMarkPartialArrayMinSizeShift);
284 const size_t size = entry.partial_array_length() * oopSize;
285
286 follow_array(addr, size, finalizable);
287 }
288
289 void ZMark::follow_array_object(objArrayOop obj, bool finalizable) {
290 const uintptr_t addr = (uintptr_t)obj->base();
291 const size_t size = (size_t)obj->length() * oopSize;
292
293 follow_array(addr, size, finalizable);
294 }
295
296 void ZMark::follow_object(oop obj, bool finalizable) {
297 if (finalizable) {
298 ZMarkBarrierOopClosure<true /* finalizable */> cl;
299 obj->oop_iterate(&cl);
300 } else {
301 ZMarkBarrierOopClosure<false /* finalizable */> cl;
302 obj->oop_iterate(&cl);
303 }
304 }
305
306 bool ZMark::try_mark_object(ZMarkCache* cache, uintptr_t addr, bool finalizable) {
307 ZPage* const page = _pagetable->get(addr);
308 if (page->is_allocating()) {
309 // Newly allocated objects are implicitly marked
310 return false;
311 }
312
313 // Try mark object
314 bool inc_live = false;
315 const bool success = page->mark_object(addr, finalizable, inc_live);
316 if (inc_live) {
317 // Update live objects/bytes for page. We use the aligned object
318 // size since that is the actual number of bytes used on the page
319 // and alignment paddings can never be reclaimed.
320 const size_t size = ZUtils::object_size(addr);
321 const size_t aligned_size = align_up(size, page->object_alignment());
322 cache->inc_live(page, aligned_size);
323 }
324
325 return success;
326 }
327
328 void ZMark::mark_and_follow(ZMarkCache* cache, ZMarkStackEntry entry) {
329 // Decode flags
330 const bool finalizable = entry.finalizable();
331 const bool partial_array = entry.partial_array();
332
333 if (partial_array) {
334 follow_partial_array(entry, finalizable);
335 return;
336 }
337
338 // Decode object address
339 const uintptr_t addr = entry.object_address();
340
341 if (!try_mark_object(cache, addr, finalizable)) {
342 // Already marked
343 return;
344 }
345
346 if (is_array(addr)) {
347 follow_array_object(objArrayOop(ZOop::to_oop(addr)), finalizable);
348 } else {
349 follow_object(ZOop::to_oop(addr), finalizable);
350 }
351 }
352
353 template <typename T>
354 bool ZMark::drain(ZMarkStripe* stripe, ZMarkThreadLocalStacks* stacks, ZMarkCache* cache, T* timeout) {
355 ZMarkStackEntry entry;
356
357 // Drain stripe stacks
358 while (stacks->pop(&_allocator, &_stripes, stripe, entry)) {
359 mark_and_follow(cache, entry);
360
361 // Check timeout
362 if (timeout->has_expired()) {
363 // Timeout
364 return false;
365 }
366 }
367
368 // Success
369 return true;
370 }
371
372 template <typename T>
373 bool ZMark::drain_and_flush(ZMarkStripe* stripe, ZMarkThreadLocalStacks* stacks, ZMarkCache* cache, T* timeout) {
374 const bool success = drain(stripe, stacks, cache, timeout);
375
376 // Flush and publish worker stacks
377 stacks->flush(&_allocator, &_stripes);
378
379 return success;
380 }
381
382 bool ZMark::try_steal(ZMarkStripe* stripe, ZMarkThreadLocalStacks* stacks) {
383 // Try to steal a stack from another stripe
384 for (ZMarkStripe* victim_stripe = _stripes.stripe_next(stripe);
385 victim_stripe != stripe;
386 victim_stripe = _stripes.stripe_next(victim_stripe)) {
387 ZMarkStack* const stack = victim_stripe->steal_stack();
388 if (stack != NULL) {
389 // Success, install the stolen stack
390 stacks->install(&_stripes, stripe, stack);
391 return true;
392 }
393 }
394
395 // Nothing to steal
396 return false;
397 }
398
399 void ZMark::idle() const {
400 ZStatTimer timer(ZSubPhaseConcurrentMarkIdle);
401 os::naked_short_sleep(1);
402 }
403
404 class ZMarkFlushAndFreeStacksClosure : public ThreadClosure {
405 private:
406 ZMark* const _mark;
407 bool _flushed;
408
409 public:
410 ZMarkFlushAndFreeStacksClosure(ZMark* mark) :
411 _mark(mark),
412 _flushed(false) {}
413
414 void do_thread(Thread* thread) {
415 if (_mark->flush_and_free(thread)) {
416 _flushed = true;
417 }
418 }
419
420 bool flushed() const {
421 return _flushed;
422 }
423 };
424
425 bool ZMark::flush(bool at_safepoint) {
426 ZMarkFlushAndFreeStacksClosure cl(this);
427 if (at_safepoint) {
428 Threads::threads_do(&cl);
429 } else {
430 Handshake::execute(&cl);
431 }
432
433 // Returns true if more work is available
434 return cl.flushed() || !_stripes.is_empty();
435 }
436
437 bool ZMark::try_flush(volatile size_t* nflush) {
438 // Only flush if handshakes are enabled
439 if (!ThreadLocalHandshakes) {
440 return false;
441 }
442
443 Atomic::inc(nflush);
444
445 ZStatTimer timer(ZSubPhaseConcurrentMarkTryFlush);
446 return flush(false /* at_safepoint */);
447 }
448
449 bool ZMark::try_proactive_flush() {
450 // Only do proactive flushes from worker 0
451 if (ZThread::worker_id() != 0) {
452 return false;
453 }
454
455 if (Atomic::load(&_work_nproactiveflush) == ZMarkProactiveFlushMax ||
456 Atomic::load(&_work_nterminateflush) != 0) {
457 // Limit reached or we're trying to terminate
458 return false;
459 }
460
461 return try_flush(&_work_nproactiveflush);
462 }
463
464 bool ZMark::try_terminate() {
465 ZStatTimer timer(ZSubPhaseConcurrentMarkTryTerminate);
466
467 if (_terminate.enter_stage0()) {
468 // Last thread entered stage 0, flush
469 if (Atomic::load(&_work_terminateflush) &&
470 Atomic::load(&_work_nterminateflush) != ZMarkTerminateFlushMax) {
471 // Exit stage 0 to allow other threads to continue marking
472 _terminate.exit_stage0();
473
474 // Flush before termination
475 if (!try_flush(&_work_nterminateflush)) {
476 // No more work available, skip further flush attempts
477 Atomic::store(false, &_work_terminateflush);
478 }
479
480 // Don't terminate, regardless of whether we successfully
481 // flushed out more work or not. We've already exited
482 // termination stage 0, to allow other threads to continue
483 // marking, so this thread has to return false and also
484 // make another round of attempted marking.
485 return false;
486 }
487 }
488
489 for (;;) {
490 if (_terminate.enter_stage1()) {
491 // Last thread entered stage 1, terminate
492 return true;
493 }
494
495 // Idle to give the other threads
496 // a chance to enter termination.
497 idle();
498
499 if (!_terminate.try_exit_stage1()) {
500 // All workers in stage 1, terminate
501 return true;
502 }
503
504 if (_terminate.try_exit_stage0()) {
505 // More work available, don't terminate
506 return false;
507 }
508 }
509 }
510
511 class ZMarkNoTimeout : public StackObj {
512 public:
513 bool has_expired() {
514 return false;
515 }
516 };
517
518 void ZMark::work_without_timeout(ZMarkCache* cache, ZMarkStripe* stripe, ZMarkThreadLocalStacks* stacks) {
519 ZStatTimer timer(ZSubPhaseConcurrentMark);
520 ZMarkNoTimeout no_timeout;
521
522 for (;;) {
523 drain_and_flush(stripe, stacks, cache, &no_timeout);
524
525 if (try_steal(stripe, stacks)) {
526 // Stole work
527 continue;
528 }
529
530 if (try_proactive_flush()) {
531 // Work available
532 continue;
533 }
534
535 if (try_terminate()) {
536 // Terminate
537 break;
538 }
539 }
540 }
541
542 class ZMarkTimeout : public StackObj {
543 private:
544 const Ticks _start;
545 const uint64_t _timeout;
546 const uint64_t _check_interval;
547 uint64_t _check_at;
548 uint64_t _check_count;
549 bool _expired;
550
551 public:
552 ZMarkTimeout(uint64_t timeout_in_millis) :
553 _start(Ticks::now()),
554 _timeout(_start.value() + TimeHelper::millis_to_counter(timeout_in_millis)),
555 _check_interval(200),
556 _check_at(_check_interval),
557 _check_count(0),
558 _expired(false) {}
559
560 ~ZMarkTimeout() {
561 const Tickspan duration = Ticks::now() - _start;
562 log_debug(gc, marking)("Mark With Timeout (%s): %s, " UINT64_FORMAT " oops, %.3fms",
563 ZThread::name(), _expired ? "Expired" : "Completed",
564 _check_count, TimeHelper::counter_to_millis(duration.value()));
565 }
566
567 bool has_expired() {
568 if (++_check_count == _check_at) {
569 _check_at += _check_interval;
570 if ((uint64_t)Ticks::now().value() >= _timeout) {
571 // Timeout
572 _expired = true;
573 }
574 }
575
576 return _expired;
577 }
578 };
579
580 void ZMark::work_with_timeout(ZMarkCache* cache, ZMarkStripe* stripe, ZMarkThreadLocalStacks* stacks, uint64_t timeout_in_millis) {
581 ZStatTimer timer(ZSubPhaseMarkTryComplete);
582 ZMarkTimeout timeout(timeout_in_millis);
583
584 for (;;) {
585 if (!drain_and_flush(stripe, stacks, cache, &timeout)) {
586 // Timed out
587 break;
588 }
589
590 if (try_steal(stripe, stacks)) {
591 // Stole work
592 continue;
593 }
594
595 // Terminate
596 break;
597 }
598 }
599
600 void ZMark::work(uint64_t timeout_in_millis) {
601 ZMarkCache cache(_stripes.nstripes());
602 ZMarkStripe* const stripe = _stripes.stripe_for_worker(_nworkers, ZThread::worker_id());
603 ZMarkThreadLocalStacks* const stacks = ZThreadLocalData::stacks(Thread::current());
604
605 if (timeout_in_millis == 0) {
606 work_without_timeout(&cache, stripe, stacks);
607 } else {
608 work_with_timeout(&cache, stripe, stacks, timeout_in_millis);
609 }
610
611 // Make sure stacks have been flushed
612 assert(stacks->is_empty(&_stripes), "Should be empty");
613
614 // Free remaining stacks
615 stacks->free(&_allocator);
616 }
617
618 class ZMarkTask : public ZTask {
619 private:
620 ZMark* const _mark;
621 const uint64_t _timeout_in_millis;
622
623 public:
624 ZMarkTask(ZMark* mark, uint64_t timeout_in_millis = 0) :
625 ZTask("ZMarkTask"),
626 _mark(mark),
627 _timeout_in_millis(timeout_in_millis) {
628 _mark->prepare_work();
629 }
630
631 ~ZMarkTask() {
632 _mark->finish_work();
633 }
634
635 virtual void work() {
636 _mark->work(_timeout_in_millis);
637 }
638 };
639
640 void ZMark::mark() {
641 ZMarkTask task(this);
642 _workers->run_concurrent(&task);
643 }
644
645 bool ZMark::try_complete() {
646 _ntrycomplete++;
647
648 // Use nconcurrent number of worker threads to maintain the
649 // worker/stripe distribution used during concurrent mark.
650 ZMarkTask task(this, ZMarkCompleteTimeout);
651 _workers->run_concurrent(&task);
652
653 // Successful if all stripes are empty
654 return _stripes.is_empty();
655 }
656
657 bool ZMark::try_end() {
658 // Flush all mark stacks
659 if (!flush(true /* at_safepoint */)) {
660 // Mark completed
661 return true;
662 }
663
664 // Try complete marking by doing a limited
665 // amount of mark work in this phase.
666 return try_complete();
667 }
668
669 bool ZMark::end() {
670 // Try end marking
671 if (!try_end()) {
672 // Mark not completed
673 _ncontinue++;
674 return false;
675 }
676
677 // Verification
678 if (ZVerifyMarking) {
679 verify_all_stacks_empty();
680 }
681
682 // Update statistics
683 ZStatMark::set_at_mark_end(_nproactiveflush, _nterminateflush, _ntrycomplete, _ncontinue);
684
685 // Mark completed
686 return true;
687 }
688
689 void ZMark::flush_and_free() {
690 Thread* const thread = Thread::current();
691 flush_and_free(thread);
692 }
693
694 bool ZMark::flush_and_free(Thread* thread) {
695 ZMarkThreadLocalStacks* const stacks = ZThreadLocalData::stacks(thread);
696 const bool flushed = stacks->flush(&_allocator, &_stripes);
697 stacks->free(&_allocator);
698 return flushed;
699 }
700
701 class ZVerifyMarkStacksEmptyClosure : public ThreadClosure {
702 private:
703 const ZMarkStripeSet* const _stripes;
704
705 public:
706 ZVerifyMarkStacksEmptyClosure(const ZMarkStripeSet* stripes) :
707 _stripes(stripes) {}
708
709 void do_thread(Thread* thread) {
710 ZMarkThreadLocalStacks* const stacks = ZThreadLocalData::stacks(thread);
711 guarantee(stacks->is_empty(_stripes), "Should be empty");
712 }
713 };
714
715 void ZMark::verify_all_stacks_empty() const {
716 // Verify thread stacks
717 ZVerifyMarkStacksEmptyClosure cl(&_stripes);
718 Threads::threads_do(&cl);
719
720 // Verify stripe stacks
721 guarantee(_stripes.is_empty(), "Should be empty");
722 }