1 /*
2 * Copyright (c) 2000, 2020, 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 "aot/aotLoader.hpp"
27 #include "classfile/classLoaderDataGraph.hpp"
28 #include "classfile/symbolTable.hpp"
29 #include "classfile/stringTable.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "code/codeCache.hpp"
32 #include "code/icBuffer.hpp"
33 #include "gc/serial/defNewGeneration.hpp"
34 #include "gc/shared/adaptiveSizePolicy.hpp"
35 #include "gc/shared/cardTableBarrierSet.hpp"
36 #include "gc/shared/cardTableRS.hpp"
37 #include "gc/shared/collectedHeap.inline.hpp"
38 #include "gc/shared/collectorCounters.hpp"
39 #include "gc/shared/gcId.hpp"
40 #include "gc/shared/gcLocker.hpp"
41 #include "gc/shared/gcPolicyCounters.hpp"
42 #include "gc/shared/gcTrace.hpp"
43 #include "gc/shared/gcTraceTime.inline.hpp"
44 #include "gc/shared/genArguments.hpp"
45 #include "gc/shared/gcVMOperations.hpp"
46 #include "gc/shared/genCollectedHeap.hpp"
47 #include "gc/shared/genOopClosures.inline.hpp"
48 #include "gc/shared/generationSpec.hpp"
49 #include "gc/shared/gcInitLogger.hpp"
50 #include "gc/shared/locationPrinter.inline.hpp"
51 #include "gc/shared/oopStorage.inline.hpp"
52 #include "gc/shared/oopStorageSet.inline.hpp"
53 #include "gc/shared/oopStorageParState.inline.hpp"
54 #include "gc/shared/scavengableNMethods.hpp"
55 #include "gc/shared/space.hpp"
56 #include "gc/shared/strongRootsScope.hpp"
57 #include "gc/shared/weakProcessor.hpp"
58 #include "gc/shared/workgroup.hpp"
59 #include "memory/filemap.hpp"
60 #include "memory/iterator.hpp"
61 #include "memory/metaspaceCounters.hpp"
62 #include "memory/metaspace/metaspaceSizesSnapshot.hpp"
63 #include "memory/resourceArea.hpp"
64 #include "memory/universe.hpp"
65 #include "oops/oop.inline.hpp"
66 #include "runtime/biasedLocking.hpp"
67 #include "runtime/handles.hpp"
68 #include "runtime/handles.inline.hpp"
69 #include "runtime/java.hpp"
70 #include "runtime/vmThread.hpp"
71 #include "services/memoryService.hpp"
72 #include "utilities/autoRestore.hpp"
73 #include "utilities/debug.hpp"
74 #include "utilities/formatBuffer.hpp"
75 #include "utilities/macros.hpp"
76 #include "utilities/stack.inline.hpp"
77 #include "utilities/vmError.hpp"
78 #if INCLUDE_JVMCI
79 #include "jvmci/jvmci.hpp"
80 #endif
81
82 GenCollectedHeap::GenCollectedHeap(Generation::Name young,
83 Generation::Name old,
84 const char* policy_counters_name) :
85 CollectedHeap(),
86 _young_gen(NULL),
87 _old_gen(NULL),
88 _young_gen_spec(new GenerationSpec(young,
89 NewSize,
90 MaxNewSize,
91 GenAlignment)),
92 _old_gen_spec(new GenerationSpec(old,
93 OldSize,
94 MaxOldSize,
95 GenAlignment)),
96 _rem_set(NULL),
97 _soft_ref_gen_policy(),
98 _size_policy(NULL),
99 _gc_policy_counters(new GCPolicyCounters(policy_counters_name, 2, 2)),
100 _incremental_collection_failed(false),
101 _full_collections_completed(0),
102 _process_strong_tasks(new SubTasksDone(GCH_PS_NumElements)),
103 _young_manager(NULL),
104 _old_manager(NULL) {
105 }
106
107 jint GenCollectedHeap::initialize() {
108 // While there are no constraints in the GC code that HeapWordSize
109 // be any particular value, there are multiple other areas in the
110 // system which believe this to be true (e.g. oop->object_size in some
111 // cases incorrectly returns the size in wordSize units rather than
112 // HeapWordSize).
113 guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize");
114
115 // Allocate space for the heap.
116
117 ReservedHeapSpace heap_rs = allocate(HeapAlignment);
118
119 if (!heap_rs.is_reserved()) {
120 vm_shutdown_during_initialization(
121 "Could not reserve enough space for object heap");
122 return JNI_ENOMEM;
123 }
124
125 initialize_reserved_region(heap_rs);
126
127 _rem_set = create_rem_set(heap_rs.region());
128 _rem_set->initialize();
129 CardTableBarrierSet *bs = new CardTableBarrierSet(_rem_set);
130 bs->initialize();
131 BarrierSet::set_barrier_set(bs);
132
133 ReservedSpace young_rs = heap_rs.first_part(_young_gen_spec->max_size());
134 _young_gen = _young_gen_spec->init(young_rs, rem_set());
135 ReservedSpace old_rs = heap_rs.last_part(_young_gen_spec->max_size());
136
137 old_rs = old_rs.first_part(_old_gen_spec->max_size());
138 _old_gen = _old_gen_spec->init(old_rs, rem_set());
139
140 GCInitLogger::print();
141
142 return JNI_OK;
143 }
144
145 CardTableRS* GenCollectedHeap::create_rem_set(const MemRegion& reserved_region) {
146 return new CardTableRS(reserved_region, false /* scan_concurrently */);
147 }
148
149 void GenCollectedHeap::initialize_size_policy(size_t init_eden_size,
150 size_t init_promo_size,
151 size_t init_survivor_size) {
152 const double max_gc_pause_sec = ((double) MaxGCPauseMillis) / 1000.0;
153 _size_policy = new AdaptiveSizePolicy(init_eden_size,
154 init_promo_size,
155 init_survivor_size,
156 max_gc_pause_sec,
157 GCTimeRatio);
158 }
159
160 ReservedHeapSpace GenCollectedHeap::allocate(size_t alignment) {
161 // Now figure out the total size.
162 const size_t pageSize = UseLargePages ? os::large_page_size() : os::vm_page_size();
163 assert(alignment % pageSize == 0, "Must be");
164
165 // Check for overflow.
166 size_t total_reserved = _young_gen_spec->max_size() + _old_gen_spec->max_size();
167 if (total_reserved < _young_gen_spec->max_size()) {
168 vm_exit_during_initialization("The size of the object heap + VM data exceeds "
169 "the maximum representable size");
170 }
171 assert(total_reserved % alignment == 0,
172 "Gen size; total_reserved=" SIZE_FORMAT ", alignment="
173 SIZE_FORMAT, total_reserved, alignment);
174
175 ReservedHeapSpace heap_rs = Universe::reserve_heap(total_reserved, alignment);
176
177 os::trace_page_sizes("Heap",
178 MinHeapSize,
179 total_reserved,
180 alignment,
181 heap_rs.base(),
182 heap_rs.size());
183
184 return heap_rs;
185 }
186
187 class GenIsScavengable : public BoolObjectClosure {
188 public:
189 bool do_object_b(oop obj) {
190 return GenCollectedHeap::heap()->is_in_young(obj);
191 }
192 };
193
194 static GenIsScavengable _is_scavengable;
195
196 void GenCollectedHeap::post_initialize() {
197 CollectedHeap::post_initialize();
198 ref_processing_init();
199
200 DefNewGeneration* def_new_gen = (DefNewGeneration*)_young_gen;
201
202 initialize_size_policy(def_new_gen->eden()->capacity(),
203 _old_gen->capacity(),
204 def_new_gen->from()->capacity());
205
206 MarkSweep::initialize();
207
208 ScavengableNMethods::initialize(&_is_scavengable);
209 }
210
211 void GenCollectedHeap::ref_processing_init() {
212 _young_gen->ref_processor_init();
213 _old_gen->ref_processor_init();
214 }
215
216 PreGenGCValues GenCollectedHeap::get_pre_gc_values() const {
217 const DefNewGeneration* const def_new_gen = (DefNewGeneration*) young_gen();
218
219 return PreGenGCValues(def_new_gen->used(),
220 def_new_gen->capacity(),
221 def_new_gen->eden()->used(),
222 def_new_gen->eden()->capacity(),
223 def_new_gen->from()->used(),
224 def_new_gen->from()->capacity(),
225 old_gen()->used(),
226 old_gen()->capacity());
227 }
228
229 GenerationSpec* GenCollectedHeap::young_gen_spec() const {
230 return _young_gen_spec;
231 }
232
233 GenerationSpec* GenCollectedHeap::old_gen_spec() const {
234 return _old_gen_spec;
235 }
236
237 size_t GenCollectedHeap::capacity() const {
238 return _young_gen->capacity() + _old_gen->capacity();
239 }
240
241 size_t GenCollectedHeap::used() const {
242 return _young_gen->used() + _old_gen->used();
243 }
244
245 void GenCollectedHeap::save_used_regions() {
246 _old_gen->save_used_region();
247 _young_gen->save_used_region();
248 }
249
250 size_t GenCollectedHeap::max_capacity() const {
251 return _young_gen->max_capacity() + _old_gen->max_capacity();
252 }
253
254 // Update the _full_collections_completed counter
255 // at the end of a stop-world full GC.
256 unsigned int GenCollectedHeap::update_full_collections_completed() {
257 MonitorLocker ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
258 assert(_full_collections_completed <= _total_full_collections,
259 "Can't complete more collections than were started");
260 _full_collections_completed = _total_full_collections;
261 ml.notify_all();
262 return _full_collections_completed;
263 }
264
265 // Update the _full_collections_completed counter, as appropriate,
266 // at the end of a concurrent GC cycle. Note the conditional update
267 // below to allow this method to be called by a concurrent collector
268 // without synchronizing in any manner with the VM thread (which
269 // may already have initiated a STW full collection "concurrently").
270 unsigned int GenCollectedHeap::update_full_collections_completed(unsigned int count) {
271 MonitorLocker ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
272 assert((_full_collections_completed <= _total_full_collections) &&
273 (count <= _total_full_collections),
274 "Can't complete more collections than were started");
275 if (count > _full_collections_completed) {
276 _full_collections_completed = count;
277 ml.notify_all();
278 }
279 return _full_collections_completed;
280 }
281
282 // Return true if any of the following is true:
283 // . the allocation won't fit into the current young gen heap
284 // . gc locker is occupied (jni critical section)
285 // . heap memory is tight -- the most recent previous collection
286 // was a full collection because a partial collection (would
287 // have) failed and is likely to fail again
288 bool GenCollectedHeap::should_try_older_generation_allocation(size_t word_size) const {
289 size_t young_capacity = _young_gen->capacity_before_gc();
290 return (word_size > heap_word_size(young_capacity))
291 || GCLocker::is_active_and_needs_gc()
292 || incremental_collection_failed();
293 }
294
295 HeapWord* GenCollectedHeap::expand_heap_and_allocate(size_t size, bool is_tlab) {
296 HeapWord* result = NULL;
297 if (_old_gen->should_allocate(size, is_tlab)) {
298 result = _old_gen->expand_and_allocate(size, is_tlab);
299 }
300 if (result == NULL) {
301 if (_young_gen->should_allocate(size, is_tlab)) {
302 result = _young_gen->expand_and_allocate(size, is_tlab);
303 }
304 }
305 assert(result == NULL || is_in_reserved(result), "result not in heap");
306 return result;
307 }
308
309 HeapWord* GenCollectedHeap::mem_allocate_work(size_t size,
310 bool is_tlab,
311 bool* gc_overhead_limit_was_exceeded) {
312 // In general gc_overhead_limit_was_exceeded should be false so
313 // set it so here and reset it to true only if the gc time
314 // limit is being exceeded as checked below.
315 *gc_overhead_limit_was_exceeded = false;
316
317 HeapWord* result = NULL;
318
319 // Loop until the allocation is satisfied, or unsatisfied after GC.
320 for (uint try_count = 1, gclocker_stalled_count = 0; /* return or throw */; try_count += 1) {
321
322 // First allocation attempt is lock-free.
323 Generation *young = _young_gen;
324 assert(young->supports_inline_contig_alloc(),
325 "Otherwise, must do alloc within heap lock");
326 if (young->should_allocate(size, is_tlab)) {
327 result = young->par_allocate(size, is_tlab);
328 if (result != NULL) {
329 assert(is_in_reserved(result), "result not in heap");
330 return result;
331 }
332 }
333 uint gc_count_before; // Read inside the Heap_lock locked region.
334 {
335 MutexLocker ml(Heap_lock);
336 log_trace(gc, alloc)("GenCollectedHeap::mem_allocate_work: attempting locked slow path allocation");
337 // Note that only large objects get a shot at being
338 // allocated in later generations.
339 bool first_only = !should_try_older_generation_allocation(size);
340
341 result = attempt_allocation(size, is_tlab, first_only);
342 if (result != NULL) {
343 assert(is_in_reserved(result), "result not in heap");
344 return result;
345 }
346
347 if (GCLocker::is_active_and_needs_gc()) {
348 if (is_tlab) {
349 return NULL; // Caller will retry allocating individual object.
350 }
351 if (!is_maximal_no_gc()) {
352 // Try and expand heap to satisfy request.
353 result = expand_heap_and_allocate(size, is_tlab);
354 // Result could be null if we are out of space.
355 if (result != NULL) {
356 return result;
357 }
358 }
359
360 if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
361 return NULL; // We didn't get to do a GC and we didn't get any memory.
362 }
363
364 // If this thread is not in a jni critical section, we stall
365 // the requestor until the critical section has cleared and
366 // GC allowed. When the critical section clears, a GC is
367 // initiated by the last thread exiting the critical section; so
368 // we retry the allocation sequence from the beginning of the loop,
369 // rather than causing more, now probably unnecessary, GC attempts.
370 JavaThread* jthr = JavaThread::current();
371 if (!jthr->in_critical()) {
372 MutexUnlocker mul(Heap_lock);
373 // Wait for JNI critical section to be exited
374 GCLocker::stall_until_clear();
375 gclocker_stalled_count += 1;
376 continue;
377 } else {
378 if (CheckJNICalls) {
379 fatal("Possible deadlock due to allocating while"
380 " in jni critical section");
381 }
382 return NULL;
383 }
384 }
385
386 // Read the gc count while the heap lock is held.
387 gc_count_before = total_collections();
388 }
389
390 VM_GenCollectForAllocation op(size, is_tlab, gc_count_before);
391 VMThread::execute(&op);
392 if (op.prologue_succeeded()) {
393 result = op.result();
394 if (op.gc_locked()) {
395 assert(result == NULL, "must be NULL if gc_locked() is true");
396 continue; // Retry and/or stall as necessary.
397 }
398
399 // Allocation has failed and a collection
400 // has been done. If the gc time limit was exceeded the
401 // this time, return NULL so that an out-of-memory
402 // will be thrown. Clear gc_overhead_limit_exceeded
403 // so that the overhead exceeded does not persist.
404
405 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
406 const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear();
407
408 if (limit_exceeded && softrefs_clear) {
409 *gc_overhead_limit_was_exceeded = true;
410 size_policy()->set_gc_overhead_limit_exceeded(false);
411 if (op.result() != NULL) {
412 CollectedHeap::fill_with_object(op.result(), size);
413 }
414 return NULL;
415 }
416 assert(result == NULL || is_in_reserved(result),
417 "result not in heap");
418 return result;
419 }
420
421 // Give a warning if we seem to be looping forever.
422 if ((QueuedAllocationWarningCount > 0) &&
423 (try_count % QueuedAllocationWarningCount == 0)) {
424 log_warning(gc, ergo)("GenCollectedHeap::mem_allocate_work retries %d times,"
425 " size=" SIZE_FORMAT " %s", try_count, size, is_tlab ? "(TLAB)" : "");
426 }
427 }
428 }
429
430 HeapWord* GenCollectedHeap::attempt_allocation(size_t size,
431 bool is_tlab,
432 bool first_only) {
433 HeapWord* res = NULL;
434
435 if (_young_gen->should_allocate(size, is_tlab)) {
436 res = _young_gen->allocate(size, is_tlab);
437 if (res != NULL || first_only) {
438 return res;
439 }
440 }
441
442 if (_old_gen->should_allocate(size, is_tlab)) {
443 res = _old_gen->allocate(size, is_tlab);
444 }
445
446 return res;
447 }
448
449 HeapWord* GenCollectedHeap::mem_allocate(size_t size,
450 bool* gc_overhead_limit_was_exceeded) {
451 return mem_allocate_work(size,
452 false /* is_tlab */,
453 gc_overhead_limit_was_exceeded);
454 }
455
456 bool GenCollectedHeap::must_clear_all_soft_refs() {
457 return _gc_cause == GCCause::_metadata_GC_clear_soft_refs ||
458 _gc_cause == GCCause::_wb_full_gc;
459 }
460
461 void GenCollectedHeap::collect_generation(Generation* gen, bool full, size_t size,
462 bool is_tlab, bool run_verification, bool clear_soft_refs,
463 bool restore_marks_for_biased_locking) {
464 FormatBuffer<> title("Collect gen: %s", gen->short_name());
465 GCTraceTime(Trace, gc, phases) t1(title);
466 TraceCollectorStats tcs(gen->counters());
467 TraceMemoryManagerStats tmms(gen->gc_manager(), gc_cause());
468
469 gen->stat_record()->invocations++;
470 gen->stat_record()->accumulated_time.start();
471
472 // Must be done anew before each collection because
473 // a previous collection will do mangling and will
474 // change top of some spaces.
475 record_gen_tops_before_GC();
476
477 log_trace(gc)("%s invoke=%d size=" SIZE_FORMAT, heap()->is_young_gen(gen) ? "Young" : "Old", gen->stat_record()->invocations, size * HeapWordSize);
478
479 if (run_verification && VerifyBeforeGC) {
480 Universe::verify("Before GC");
481 }
482 COMPILER2_OR_JVMCI_PRESENT(DerivedPointerTable::clear());
483
484 if (restore_marks_for_biased_locking) {
485 // We perform this mark word preservation work lazily
486 // because it's only at this point that we know whether we
487 // absolutely have to do it; we want to avoid doing it for
488 // scavenge-only collections where it's unnecessary
489 BiasedLocking::preserve_marks();
490 }
491
492 // Do collection work
493 {
494 // Note on ref discovery: For what appear to be historical reasons,
495 // GCH enables and disabled (by enqueing) refs discovery.
496 // In the future this should be moved into the generation's
497 // collect method so that ref discovery and enqueueing concerns
498 // are local to a generation. The collect method could return
499 // an appropriate indication in the case that notification on
500 // the ref lock was needed. This will make the treatment of
501 // weak refs more uniform (and indeed remove such concerns
502 // from GCH). XXX
503
504 save_marks(); // save marks for all gens
505 // We want to discover references, but not process them yet.
506 // This mode is disabled in process_discovered_references if the
507 // generation does some collection work, or in
508 // enqueue_discovered_references if the generation returns
509 // without doing any work.
510 ReferenceProcessor* rp = gen->ref_processor();
511 // If the discovery of ("weak") refs in this generation is
512 // atomic wrt other collectors in this configuration, we
513 // are guaranteed to have empty discovered ref lists.
514 if (rp->discovery_is_atomic()) {
515 rp->enable_discovery();
516 rp->setup_policy(clear_soft_refs);
517 } else {
518 // collect() below will enable discovery as appropriate
519 }
520 gen->collect(full, clear_soft_refs, size, is_tlab);
521 if (!rp->enqueuing_is_done()) {
522 rp->disable_discovery();
523 } else {
524 rp->set_enqueuing_is_done(false);
525 }
526 rp->verify_no_references_recorded();
527 }
528
529 COMPILER2_OR_JVMCI_PRESENT(DerivedPointerTable::update_pointers());
530
531 gen->stat_record()->accumulated_time.stop();
532
533 update_gc_stats(gen, full);
534
535 if (run_verification && VerifyAfterGC) {
536 Universe::verify("After GC");
537 }
538 }
539
540 void GenCollectedHeap::do_collection(bool full,
541 bool clear_all_soft_refs,
542 size_t size,
543 bool is_tlab,
544 GenerationType max_generation) {
545 ResourceMark rm;
546 DEBUG_ONLY(Thread* my_thread = Thread::current();)
547
548 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
549 assert(my_thread->is_VM_thread() ||
550 my_thread->is_ConcurrentGC_thread(),
551 "incorrect thread type capability");
552 assert(Heap_lock->is_locked(),
553 "the requesting thread should have the Heap_lock");
554 guarantee(!is_gc_active(), "collection is not reentrant");
555
556 if (GCLocker::check_active_before_gc()) {
557 return; // GC is disabled (e.g. JNI GetXXXCritical operation)
558 }
559
560 const bool do_clear_all_soft_refs = clear_all_soft_refs ||
561 soft_ref_policy()->should_clear_all_soft_refs();
562
563 ClearedAllSoftRefs casr(do_clear_all_soft_refs, soft_ref_policy());
564
565 AutoModifyRestore<bool> temporarily(_is_gc_active, true);
566
567 bool complete = full && (max_generation == OldGen);
568 bool old_collects_young = complete && !ScavengeBeforeFullGC;
569 bool do_young_collection = !old_collects_young && _young_gen->should_collect(full, size, is_tlab);
570
571 const PreGenGCValues pre_gc_values = get_pre_gc_values();
572
573 bool run_verification = total_collections() >= VerifyGCStartAt;
574 bool prepared_for_verification = false;
575 bool do_full_collection = false;
576
577 if (do_young_collection) {
578 GCIdMark gc_id_mark;
579 GCTraceCPUTime tcpu;
580 GCTraceTime(Info, gc) t("Pause Young", NULL, gc_cause(), true);
581
582 print_heap_before_gc();
583
584 if (run_verification && VerifyGCLevel <= 0 && VerifyBeforeGC) {
585 prepare_for_verify();
586 prepared_for_verification = true;
587 }
588
589 gc_prologue(complete);
590 increment_total_collections(complete);
591
592 collect_generation(_young_gen,
593 full,
594 size,
595 is_tlab,
596 run_verification && VerifyGCLevel <= 0,
597 do_clear_all_soft_refs,
598 false);
599
600 if (size > 0 && (!is_tlab || _young_gen->supports_tlab_allocation()) &&
601 size * HeapWordSize <= _young_gen->unsafe_max_alloc_nogc()) {
602 // Allocation request was met by young GC.
603 size = 0;
604 }
605
606 // Ask if young collection is enough. If so, do the final steps for young collection,
607 // and fallthrough to the end.
608 do_full_collection = should_do_full_collection(size, full, is_tlab, max_generation);
609 if (!do_full_collection) {
610 // Adjust generation sizes.
611 _young_gen->compute_new_size();
612
613 print_heap_change(pre_gc_values);
614
615 // Track memory usage and detect low memory after GC finishes
616 MemoryService::track_memory_usage();
617
618 gc_epilogue(complete);
619 }
620
621 print_heap_after_gc();
622
623 } else {
624 // No young collection, ask if we need to perform Full collection.
625 do_full_collection = should_do_full_collection(size, full, is_tlab, max_generation);
626 }
627
628 if (do_full_collection) {
629 GCIdMark gc_id_mark;
630 GCTraceCPUTime tcpu;
631 GCTraceTime(Info, gc) t("Pause Full", NULL, gc_cause(), true);
632
633 print_heap_before_gc();
634
635 if (!prepared_for_verification && run_verification &&
636 VerifyGCLevel <= 1 && VerifyBeforeGC) {
637 prepare_for_verify();
638 }
639
640 if (!do_young_collection) {
641 gc_prologue(complete);
642 increment_total_collections(complete);
643 }
644
645 // Accounting quirk: total full collections would be incremented when "complete"
646 // is set, by calling increment_total_collections above. However, we also need to
647 // account Full collections that had "complete" unset.
648 if (!complete) {
649 increment_total_full_collections();
650 }
651
652 collect_generation(_old_gen,
653 full,
654 size,
655 is_tlab,
656 run_verification && VerifyGCLevel <= 1,
657 do_clear_all_soft_refs,
658 true);
659
660 // Adjust generation sizes.
661 _old_gen->compute_new_size();
662 _young_gen->compute_new_size();
663
664 // Delete metaspaces for unloaded class loaders and clean up loader_data graph
665 ClassLoaderDataGraph::purge();
666 DEBUG_ONLY(MetaspaceUtils::verify(false);)
667 // Resize the metaspace capacity after full collections
668 MetaspaceGC::compute_new_size();
669 update_full_collections_completed();
670
671 print_heap_change(pre_gc_values);
672
673 // Track memory usage and detect low memory after GC finishes
674 MemoryService::track_memory_usage();
675
676 // Need to tell the epilogue code we are done with Full GC, regardless what was
677 // the initial value for "complete" flag.
678 gc_epilogue(true);
679
680 BiasedLocking::restore_marks();
681
682 print_heap_after_gc();
683 }
684 }
685
686 bool GenCollectedHeap::should_do_full_collection(size_t size, bool full, bool is_tlab,
687 GenCollectedHeap::GenerationType max_gen) const {
688 return max_gen == OldGen && _old_gen->should_collect(full, size, is_tlab);
689 }
690
691 void GenCollectedHeap::register_nmethod(nmethod* nm) {
692 ScavengableNMethods::register_nmethod(nm);
693 }
694
695 void GenCollectedHeap::unregister_nmethod(nmethod* nm) {
696 ScavengableNMethods::unregister_nmethod(nm);
697 }
698
699 void GenCollectedHeap::verify_nmethod(nmethod* nm) {
700 ScavengableNMethods::verify_nmethod(nm);
701 }
702
703 void GenCollectedHeap::flush_nmethod(nmethod* nm) {
704 // Do nothing.
705 }
706
707 void GenCollectedHeap::prune_scavengable_nmethods() {
708 ScavengableNMethods::prune_nmethods();
709 }
710
711 HeapWord* GenCollectedHeap::satisfy_failed_allocation(size_t size, bool is_tlab) {
712 GCCauseSetter x(this, GCCause::_allocation_failure);
713 HeapWord* result = NULL;
714
715 assert(size != 0, "Precondition violated");
716 if (GCLocker::is_active_and_needs_gc()) {
717 // GC locker is active; instead of a collection we will attempt
718 // to expand the heap, if there's room for expansion.
719 if (!is_maximal_no_gc()) {
720 result = expand_heap_and_allocate(size, is_tlab);
721 }
722 return result; // Could be null if we are out of space.
723 } else if (!incremental_collection_will_fail(false /* don't consult_young */)) {
724 // Do an incremental collection.
725 do_collection(false, // full
726 false, // clear_all_soft_refs
727 size, // size
728 is_tlab, // is_tlab
729 GenCollectedHeap::OldGen); // max_generation
730 } else {
731 log_trace(gc)(" :: Trying full because partial may fail :: ");
732 // Try a full collection; see delta for bug id 6266275
733 // for the original code and why this has been simplified
734 // with from-space allocation criteria modified and
735 // such allocation moved out of the safepoint path.
736 do_collection(true, // full
737 false, // clear_all_soft_refs
738 size, // size
739 is_tlab, // is_tlab
740 GenCollectedHeap::OldGen); // max_generation
741 }
742
743 result = attempt_allocation(size, is_tlab, false /*first_only*/);
744
745 if (result != NULL) {
746 assert(is_in_reserved(result), "result not in heap");
747 return result;
748 }
749
750 // OK, collection failed, try expansion.
751 result = expand_heap_and_allocate(size, is_tlab);
752 if (result != NULL) {
753 return result;
754 }
755
756 // If we reach this point, we're really out of memory. Try every trick
757 // we can to reclaim memory. Force collection of soft references. Force
758 // a complete compaction of the heap. Any additional methods for finding
759 // free memory should be here, especially if they are expensive. If this
760 // attempt fails, an OOM exception will be thrown.
761 {
762 UIntFlagSetting flag_change(MarkSweepAlwaysCompactCount, 1); // Make sure the heap is fully compacted
763
764 do_collection(true, // full
765 true, // clear_all_soft_refs
766 size, // size
767 is_tlab, // is_tlab
768 GenCollectedHeap::OldGen); // max_generation
769 }
770
771 result = attempt_allocation(size, is_tlab, false /* first_only */);
772 if (result != NULL) {
773 assert(is_in_reserved(result), "result not in heap");
774 return result;
775 }
776
777 assert(!soft_ref_policy()->should_clear_all_soft_refs(),
778 "Flag should have been handled and cleared prior to this point");
779
780 // What else? We might try synchronous finalization later. If the total
781 // space available is large enough for the allocation, then a more
782 // complete compaction phase than we've tried so far might be
783 // appropriate.
784 return NULL;
785 }
786
787 #ifdef ASSERT
788 class AssertNonScavengableClosure: public OopClosure {
789 public:
790 virtual void do_oop(oop* p) {
791 assert(!GenCollectedHeap::heap()->is_in_partial_collection(*p),
792 "Referent should not be scavengable."); }
793 virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
794 };
795 static AssertNonScavengableClosure assert_is_non_scavengable_closure;
796 #endif
797
798 void GenCollectedHeap::process_roots(StrongRootsScope* scope,
799 ScanningOption so,
800 OopClosure* strong_roots,
801 CLDClosure* strong_cld_closure,
802 CLDClosure* weak_cld_closure,
803 CodeBlobToOopClosure* code_roots) {
804 // General roots.
805 assert(code_roots != NULL, "code root closure should always be set");
806 // _n_termination for _process_strong_tasks should be set up stream
807 // in a method not running in a GC worker. Otherwise the GC worker
808 // could be trying to change the termination condition while the task
809 // is executing in another GC worker.
810
811 if (_process_strong_tasks->try_claim_task(GCH_PS_ClassLoaderDataGraph_oops_do)) {
812 ClassLoaderDataGraph::roots_cld_do(strong_cld_closure, weak_cld_closure);
813 }
814
815 // Only process code roots from thread stacks if we aren't visiting the entire CodeCache anyway
816 CodeBlobToOopClosure* roots_from_code_p = (so & SO_AllCodeCache) ? NULL : code_roots;
817
818 bool is_par = scope->n_threads() > 1;
819 Threads::possibly_parallel_oops_do(is_par, strong_roots, roots_from_code_p);
820
821 if (_process_strong_tasks->try_claim_task(GCH_PS_ObjectSynchronizer_oops_do)) {
822 ObjectSynchronizer::oops_do(strong_roots);
823 }
824 #if INCLUDE_AOT
825 if (UseAOT && _process_strong_tasks->try_claim_task(GCH_PS_aot_oops_do)) {
826 AOTLoader::oops_do(strong_roots);
827 }
828 #endif
829 if (_process_strong_tasks->try_claim_task(GCH_PS_OopStorageSet_oops_do)) {
830 OopStorageSet::strong_oops_do(strong_roots);
831 }
832
833 if (_process_strong_tasks->try_claim_task(GCH_PS_CodeCache_oops_do)) {
834 if (so & SO_ScavengeCodeCache) {
835 assert(code_roots != NULL, "must supply closure for code cache");
836
837 // We only visit parts of the CodeCache when scavenging.
838 ScavengableNMethods::nmethods_do(code_roots);
839 }
840 if (so & SO_AllCodeCache) {
841 assert(code_roots != NULL, "must supply closure for code cache");
842
843 // CMSCollector uses this to do intermediate-strength collections.
844 // We scan the entire code cache, since CodeCache::do_unloading is not called.
845 CodeCache::blobs_do(code_roots);
846 }
847 // Verify that the code cache contents are not subject to
848 // movement by a scavenging collection.
849 DEBUG_ONLY(CodeBlobToOopClosure assert_code_is_non_scavengable(&assert_is_non_scavengable_closure, !CodeBlobToOopClosure::FixRelocations));
850 DEBUG_ONLY(ScavengableNMethods::asserted_non_scavengable_nmethods_do(&assert_code_is_non_scavengable));
851 }
852 }
853
854 void GenCollectedHeap::young_process_roots(StrongRootsScope* scope,
855 OopsInGenClosure* root_closure,
856 OopsInGenClosure* old_gen_closure,
857 CLDClosure* cld_closure) {
858 MarkingCodeBlobClosure mark_code_closure(root_closure, CodeBlobToOopClosure::FixRelocations);
859
860 process_roots(scope, SO_ScavengeCodeCache, root_closure,
861 cld_closure, cld_closure, &mark_code_closure);
862
863 if (_process_strong_tasks->try_claim_task(GCH_PS_younger_gens)) {
864 root_closure->reset_generation();
865 }
866
867 // When collection is parallel, all threads get to cooperate to do
868 // old generation scanning.
869 old_gen_closure->set_generation(_old_gen);
870 rem_set()->younger_refs_iterate(_old_gen, old_gen_closure, scope->n_threads());
871 old_gen_closure->reset_generation();
872
873 _process_strong_tasks->all_tasks_completed(scope->n_threads());
874 }
875
876 void GenCollectedHeap::full_process_roots(StrongRootsScope* scope,
877 bool is_adjust_phase,
878 ScanningOption so,
879 bool only_strong_roots,
880 OopsInGenClosure* root_closure,
881 CLDClosure* cld_closure) {
882 MarkingCodeBlobClosure mark_code_closure(root_closure, is_adjust_phase);
883 CLDClosure* weak_cld_closure = only_strong_roots ? NULL : cld_closure;
884
885 process_roots(scope, so, root_closure, cld_closure, weak_cld_closure, &mark_code_closure);
886 _process_strong_tasks->all_tasks_completed(scope->n_threads());
887 }
888
889 void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure) {
890 WeakProcessor::oops_do(root_closure);
891 _young_gen->ref_processor()->weak_oops_do(root_closure);
892 _old_gen->ref_processor()->weak_oops_do(root_closure);
893 }
894
895 bool GenCollectedHeap::no_allocs_since_save_marks() {
896 return _young_gen->no_allocs_since_save_marks() &&
897 _old_gen->no_allocs_since_save_marks();
898 }
899
900 bool GenCollectedHeap::supports_inline_contig_alloc() const {
901 return _young_gen->supports_inline_contig_alloc();
902 }
903
904 HeapWord* volatile* GenCollectedHeap::top_addr() const {
905 return _young_gen->top_addr();
906 }
907
908 HeapWord** GenCollectedHeap::end_addr() const {
909 return _young_gen->end_addr();
910 }
911
912 // public collection interfaces
913
914 void GenCollectedHeap::collect(GCCause::Cause cause) {
915 if ((cause == GCCause::_wb_young_gc) ||
916 (cause == GCCause::_gc_locker)) {
917 // Young collection for WhiteBox or GCLocker.
918 collect(cause, YoungGen);
919 } else {
920 #ifdef ASSERT
921 if (cause == GCCause::_scavenge_alot) {
922 // Young collection only.
923 collect(cause, YoungGen);
924 } else {
925 // Stop-the-world full collection.
926 collect(cause, OldGen);
927 }
928 #else
929 // Stop-the-world full collection.
930 collect(cause, OldGen);
931 #endif
932 }
933 }
934
935 void GenCollectedHeap::collect(GCCause::Cause cause, GenerationType max_generation) {
936 // The caller doesn't have the Heap_lock
937 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
938 MutexLocker ml(Heap_lock);
939 collect_locked(cause, max_generation);
940 }
941
942 void GenCollectedHeap::collect_locked(GCCause::Cause cause) {
943 // The caller has the Heap_lock
944 assert(Heap_lock->owned_by_self(), "this thread should own the Heap_lock");
945 collect_locked(cause, OldGen);
946 }
947
948 // this is the private collection interface
949 // The Heap_lock is expected to be held on entry.
950
951 void GenCollectedHeap::collect_locked(GCCause::Cause cause, GenerationType max_generation) {
952 // Read the GC count while holding the Heap_lock
953 unsigned int gc_count_before = total_collections();
954 unsigned int full_gc_count_before = total_full_collections();
955
956 if (GCLocker::should_discard(cause, gc_count_before)) {
957 return;
958 }
959
960 {
961 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back
962 VM_GenCollectFull op(gc_count_before, full_gc_count_before,
963 cause, max_generation);
964 VMThread::execute(&op);
965 }
966 }
967
968 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs) {
969 do_full_collection(clear_all_soft_refs, OldGen);
970 }
971
972 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs,
973 GenerationType last_generation) {
974 do_collection(true, // full
975 clear_all_soft_refs, // clear_all_soft_refs
976 0, // size
977 false, // is_tlab
978 last_generation); // last_generation
979 // Hack XXX FIX ME !!!
980 // A scavenge may not have been attempted, or may have
981 // been attempted and failed, because the old gen was too full
982 if (gc_cause() == GCCause::_gc_locker && incremental_collection_failed()) {
983 log_debug(gc, jni)("GC locker: Trying a full collection because scavenge failed");
984 // This time allow the old gen to be collected as well
985 do_collection(true, // full
986 clear_all_soft_refs, // clear_all_soft_refs
987 0, // size
988 false, // is_tlab
989 OldGen); // last_generation
990 }
991 }
992
993 bool GenCollectedHeap::is_in_young(oop p) {
994 bool result = cast_from_oop<HeapWord*>(p) < _old_gen->reserved().start();
995 assert(result == _young_gen->is_in_reserved(p),
996 "incorrect test - result=%d, p=" INTPTR_FORMAT, result, p2i((void*)p));
997 return result;
998 }
999
1000 // Returns "TRUE" iff "p" points into the committed areas of the heap.
1001 bool GenCollectedHeap::is_in(const void* p) const {
1002 return _young_gen->is_in(p) || _old_gen->is_in(p);
1003 }
1004
1005 #ifdef ASSERT
1006 // Don't implement this by using is_in_young(). This method is used
1007 // in some cases to check that is_in_young() is correct.
1008 bool GenCollectedHeap::is_in_partial_collection(const void* p) {
1009 assert(is_in_reserved(p) || p == NULL,
1010 "Does not work if address is non-null and outside of the heap");
1011 return p < _young_gen->reserved().end() && p != NULL;
1012 }
1013 #endif
1014
1015 void GenCollectedHeap::oop_iterate(OopIterateClosure* cl) {
1016 _young_gen->oop_iterate(cl);
1017 _old_gen->oop_iterate(cl);
1018 }
1019
1020 void GenCollectedHeap::object_iterate(ObjectClosure* cl) {
1021 _young_gen->object_iterate(cl);
1022 _old_gen->object_iterate(cl);
1023 }
1024
1025 Space* GenCollectedHeap::space_containing(const void* addr) const {
1026 Space* res = _young_gen->space_containing(addr);
1027 if (res != NULL) {
1028 return res;
1029 }
1030 res = _old_gen->space_containing(addr);
1031 assert(res != NULL, "Could not find containing space");
1032 return res;
1033 }
1034
1035 HeapWord* GenCollectedHeap::block_start(const void* addr) const {
1036 assert(is_in_reserved(addr), "block_start of address outside of heap");
1037 if (_young_gen->is_in_reserved(addr)) {
1038 assert(_young_gen->is_in(addr), "addr should be in allocated part of generation");
1039 return _young_gen->block_start(addr);
1040 }
1041
1042 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address");
1043 assert(_old_gen->is_in(addr), "addr should be in allocated part of generation");
1044 return _old_gen->block_start(addr);
1045 }
1046
1047 bool GenCollectedHeap::block_is_obj(const HeapWord* addr) const {
1048 assert(is_in_reserved(addr), "block_is_obj of address outside of heap");
1049 assert(block_start(addr) == addr, "addr must be a block start");
1050 if (_young_gen->is_in_reserved(addr)) {
1051 return _young_gen->block_is_obj(addr);
1052 }
1053
1054 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address");
1055 return _old_gen->block_is_obj(addr);
1056 }
1057
1058 bool GenCollectedHeap::supports_tlab_allocation() const {
1059 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!");
1060 return _young_gen->supports_tlab_allocation();
1061 }
1062
1063 size_t GenCollectedHeap::tlab_capacity(Thread* thr) const {
1064 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!");
1065 if (_young_gen->supports_tlab_allocation()) {
1066 return _young_gen->tlab_capacity();
1067 }
1068 return 0;
1069 }
1070
1071 size_t GenCollectedHeap::tlab_used(Thread* thr) const {
1072 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!");
1073 if (_young_gen->supports_tlab_allocation()) {
1074 return _young_gen->tlab_used();
1075 }
1076 return 0;
1077 }
1078
1079 size_t GenCollectedHeap::unsafe_max_tlab_alloc(Thread* thr) const {
1080 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!");
1081 if (_young_gen->supports_tlab_allocation()) {
1082 return _young_gen->unsafe_max_tlab_alloc();
1083 }
1084 return 0;
1085 }
1086
1087 HeapWord* GenCollectedHeap::allocate_new_tlab(size_t min_size,
1088 size_t requested_size,
1089 size_t* actual_size) {
1090 bool gc_overhead_limit_was_exceeded;
1091 HeapWord* result = mem_allocate_work(requested_size /* size */,
1092 true /* is_tlab */,
1093 &gc_overhead_limit_was_exceeded);
1094 if (result != NULL) {
1095 *actual_size = requested_size;
1096 }
1097
1098 return result;
1099 }
1100
1101 // Requires "*prev_ptr" to be non-NULL. Deletes and a block of minimal size
1102 // from the list headed by "*prev_ptr".
1103 static ScratchBlock *removeSmallestScratch(ScratchBlock **prev_ptr) {
1104 bool first = true;
1105 size_t min_size = 0; // "first" makes this conceptually infinite.
1106 ScratchBlock **smallest_ptr, *smallest;
1107 ScratchBlock *cur = *prev_ptr;
1108 while (cur) {
1109 assert(*prev_ptr == cur, "just checking");
1110 if (first || cur->num_words < min_size) {
1111 smallest_ptr = prev_ptr;
1112 smallest = cur;
1113 min_size = smallest->num_words;
1114 first = false;
1115 }
1116 prev_ptr = &cur->next;
1117 cur = cur->next;
1118 }
1119 smallest = *smallest_ptr;
1120 *smallest_ptr = smallest->next;
1121 return smallest;
1122 }
1123
1124 // Sort the scratch block list headed by res into decreasing size order,
1125 // and set "res" to the result.
1126 static void sort_scratch_list(ScratchBlock*& list) {
1127 ScratchBlock* sorted = NULL;
1128 ScratchBlock* unsorted = list;
1129 while (unsorted) {
1130 ScratchBlock *smallest = removeSmallestScratch(&unsorted);
1131 smallest->next = sorted;
1132 sorted = smallest;
1133 }
1134 list = sorted;
1135 }
1136
1137 ScratchBlock* GenCollectedHeap::gather_scratch(Generation* requestor,
1138 size_t max_alloc_words) {
1139 ScratchBlock* res = NULL;
1140 _young_gen->contribute_scratch(res, requestor, max_alloc_words);
1141 _old_gen->contribute_scratch(res, requestor, max_alloc_words);
1142 sort_scratch_list(res);
1143 return res;
1144 }
1145
1146 void GenCollectedHeap::release_scratch() {
1147 _young_gen->reset_scratch();
1148 _old_gen->reset_scratch();
1149 }
1150
1151 class GenPrepareForVerifyClosure: public GenCollectedHeap::GenClosure {
1152 void do_generation(Generation* gen) {
1153 gen->prepare_for_verify();
1154 }
1155 };
1156
1157 void GenCollectedHeap::prepare_for_verify() {
1158 ensure_parsability(false); // no need to retire TLABs
1159 GenPrepareForVerifyClosure blk;
1160 generation_iterate(&blk, false);
1161 }
1162
1163 void GenCollectedHeap::generation_iterate(GenClosure* cl,
1164 bool old_to_young) {
1165 if (old_to_young) {
1166 cl->do_generation(_old_gen);
1167 cl->do_generation(_young_gen);
1168 } else {
1169 cl->do_generation(_young_gen);
1170 cl->do_generation(_old_gen);
1171 }
1172 }
1173
1174 bool GenCollectedHeap::is_maximal_no_gc() const {
1175 return _young_gen->is_maximal_no_gc() && _old_gen->is_maximal_no_gc();
1176 }
1177
1178 void GenCollectedHeap::save_marks() {
1179 _young_gen->save_marks();
1180 _old_gen->save_marks();
1181 }
1182
1183 GenCollectedHeap* GenCollectedHeap::heap() {
1184 // SerialHeap is the only subtype of GenCollectedHeap.
1185 return named_heap<GenCollectedHeap>(CollectedHeap::Serial);
1186 }
1187
1188 #if INCLUDE_SERIALGC
1189 void GenCollectedHeap::prepare_for_compaction() {
1190 // Start by compacting into same gen.
1191 CompactPoint cp(_old_gen);
1192 _old_gen->prepare_for_compaction(&cp);
1193 _young_gen->prepare_for_compaction(&cp);
1194 }
1195 #endif // INCLUDE_SERIALGC
1196
1197 void GenCollectedHeap::verify(VerifyOption option /* ignored */) {
1198 log_debug(gc, verify)("%s", _old_gen->name());
1199 _old_gen->verify();
1200
1201 log_debug(gc, verify)("%s", _old_gen->name());
1202 _young_gen->verify();
1203
1204 log_debug(gc, verify)("RemSet");
1205 rem_set()->verify();
1206 }
1207
1208 void GenCollectedHeap::print_on(outputStream* st) const {
1209 if (_young_gen != NULL) {
1210 _young_gen->print_on(st);
1211 }
1212 if (_old_gen != NULL) {
1213 _old_gen->print_on(st);
1214 }
1215 MetaspaceUtils::print_on(st);
1216 }
1217
1218 void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const {
1219 }
1220
1221 bool GenCollectedHeap::print_location(outputStream* st, void* addr) const {
1222 return BlockLocationPrinter<GenCollectedHeap>::print_location(st, addr);
1223 }
1224
1225 void GenCollectedHeap::print_tracing_info() const {
1226 if (log_is_enabled(Debug, gc, heap, exit)) {
1227 LogStreamHandle(Debug, gc, heap, exit) lsh;
1228 _young_gen->print_summary_info_on(&lsh);
1229 _old_gen->print_summary_info_on(&lsh);
1230 }
1231 }
1232
1233 void GenCollectedHeap::print_heap_change(const PreGenGCValues& pre_gc_values) const {
1234 const DefNewGeneration* const def_new_gen = (DefNewGeneration*) young_gen();
1235
1236 log_info(gc, heap)(HEAP_CHANGE_FORMAT" "
1237 HEAP_CHANGE_FORMAT" "
1238 HEAP_CHANGE_FORMAT,
1239 HEAP_CHANGE_FORMAT_ARGS(def_new_gen->short_name(),
1240 pre_gc_values.young_gen_used(),
1241 pre_gc_values.young_gen_capacity(),
1242 def_new_gen->used(),
1243 def_new_gen->capacity()),
1244 HEAP_CHANGE_FORMAT_ARGS("Eden",
1245 pre_gc_values.eden_used(),
1246 pre_gc_values.eden_capacity(),
1247 def_new_gen->eden()->used(),
1248 def_new_gen->eden()->capacity()),
1249 HEAP_CHANGE_FORMAT_ARGS("From",
1250 pre_gc_values.from_used(),
1251 pre_gc_values.from_capacity(),
1252 def_new_gen->from()->used(),
1253 def_new_gen->from()->capacity()));
1254 log_info(gc, heap)(HEAP_CHANGE_FORMAT,
1255 HEAP_CHANGE_FORMAT_ARGS(old_gen()->short_name(),
1256 pre_gc_values.old_gen_used(),
1257 pre_gc_values.old_gen_capacity(),
1258 old_gen()->used(),
1259 old_gen()->capacity()));
1260 MetaspaceUtils::print_metaspace_change(pre_gc_values.metaspace_sizes());
1261 }
1262
1263 class GenGCPrologueClosure: public GenCollectedHeap::GenClosure {
1264 private:
1265 bool _full;
1266 public:
1267 void do_generation(Generation* gen) {
1268 gen->gc_prologue(_full);
1269 }
1270 GenGCPrologueClosure(bool full) : _full(full) {};
1271 };
1272
1273 void GenCollectedHeap::gc_prologue(bool full) {
1274 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer");
1275
1276 // Fill TLAB's and such
1277 ensure_parsability(true); // retire TLABs
1278
1279 // Walk generations
1280 GenGCPrologueClosure blk(full);
1281 generation_iterate(&blk, false); // not old-to-young.
1282 };
1283
1284 class GenGCEpilogueClosure: public GenCollectedHeap::GenClosure {
1285 private:
1286 bool _full;
1287 public:
1288 void do_generation(Generation* gen) {
1289 gen->gc_epilogue(_full);
1290 }
1291 GenGCEpilogueClosure(bool full) : _full(full) {};
1292 };
1293
1294 void GenCollectedHeap::gc_epilogue(bool full) {
1295 #if COMPILER2_OR_JVMCI
1296 assert(DerivedPointerTable::is_empty(), "derived pointer present");
1297 size_t actual_gap = pointer_delta((HeapWord*) (max_uintx-3), *(end_addr()));
1298 guarantee(is_client_compilation_mode_vm() || actual_gap > (size_t)FastAllocateSizeLimit, "inline allocation wraps");
1299 #endif // COMPILER2_OR_JVMCI
1300
1301 resize_all_tlabs();
1302
1303 GenGCEpilogueClosure blk(full);
1304 generation_iterate(&blk, false); // not old-to-young.
1305
1306 if (!CleanChunkPoolAsync) {
1307 Chunk::clean_chunk_pool();
1308 }
1309
1310 MetaspaceCounters::update_performance_counters();
1311 CompressedClassSpaceCounters::update_performance_counters();
1312 };
1313
1314 #ifndef PRODUCT
1315 class GenGCSaveTopsBeforeGCClosure: public GenCollectedHeap::GenClosure {
1316 private:
1317 public:
1318 void do_generation(Generation* gen) {
1319 gen->record_spaces_top();
1320 }
1321 };
1322
1323 void GenCollectedHeap::record_gen_tops_before_GC() {
1324 if (ZapUnusedHeapArea) {
1325 GenGCSaveTopsBeforeGCClosure blk;
1326 generation_iterate(&blk, false); // not old-to-young.
1327 }
1328 }
1329 #endif // not PRODUCT
1330
1331 class GenEnsureParsabilityClosure: public GenCollectedHeap::GenClosure {
1332 public:
1333 void do_generation(Generation* gen) {
1334 gen->ensure_parsability();
1335 }
1336 };
1337
1338 void GenCollectedHeap::ensure_parsability(bool retire_tlabs) {
1339 CollectedHeap::ensure_parsability(retire_tlabs);
1340 GenEnsureParsabilityClosure ep_cl;
1341 generation_iterate(&ep_cl, false);
1342 }
1343
1344 oop GenCollectedHeap::handle_failed_promotion(Generation* old_gen,
1345 oop obj,
1346 size_t obj_size) {
1347 guarantee(old_gen == _old_gen, "We only get here with an old generation");
1348 assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
1349 HeapWord* result = NULL;
1350
1351 result = old_gen->expand_and_allocate(obj_size, false);
1352
1353 if (result != NULL) {
1354 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(obj), result, obj_size);
1355 }
1356 return oop(result);
1357 }