1 /*
2 * Copyright (c) 2001, 2017, 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 "classfile/systemDictionary.hpp"
27 #include "gc/shared/allocTracer.hpp"
28 #include "gc/shared/barrierSet.inline.hpp"
29 #include "gc/shared/collectedHeap.hpp"
30 #include "gc/shared/collectedHeap.inline.hpp"
31 #include "gc/shared/gcHeapSummary.hpp"
32 #include "gc/shared/gcTrace.hpp"
33 #include "gc/shared/gcTraceTime.inline.hpp"
34 #include "gc/shared/gcWhen.hpp"
35 #include "gc/shared/vmGCOperations.hpp"
36 #include "logging/log.hpp"
37 #include "memory/metaspace.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "oops/instanceMirrorKlass.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "runtime/heapMonitoring.hpp"
42 #include "runtime/init.hpp"
43 #include "runtime/thread.inline.hpp"
44 #include "runtime/threadSMR.hpp"
45 #include "services/heapDumper.hpp"
46 #include "utilities/align.hpp"
47
48
49 #ifdef ASSERT
50 int CollectedHeap::_fire_out_of_memory_count = 0;
51 #endif
52
53 size_t CollectedHeap::_filler_array_max_size = 0;
54
55 template <>
56 void EventLogBase<GCMessage>::print(outputStream* st, GCMessage& m) {
57 st->print_cr("GC heap %s", m.is_before ? "before" : "after");
58 st->print_raw(m);
59 }
60
61 void GCHeapLog::log_heap(CollectedHeap* heap, bool before) {
62 if (!should_log()) {
63 return;
64 }
65
66 double timestamp = fetch_timestamp();
67 MutexLockerEx ml(&_mutex, Mutex::_no_safepoint_check_flag);
68 int index = compute_log_index();
69 _records[index].thread = NULL; // Its the GC thread so it's not that interesting.
70 _records[index].timestamp = timestamp;
71 _records[index].data.is_before = before;
72 stringStream st(_records[index].data.buffer(), _records[index].data.size());
73
74 st.print_cr("{Heap %s GC invocations=%u (full %u):",
75 before ? "before" : "after",
76 heap->total_collections(),
77 heap->total_full_collections());
78
79 heap->print_on(&st);
80 st.print_cr("}");
81 }
82
83 VirtualSpaceSummary CollectedHeap::create_heap_space_summary() {
84 size_t capacity_in_words = capacity() / HeapWordSize;
85
86 return VirtualSpaceSummary(
87 reserved_region().start(), reserved_region().start() + capacity_in_words, reserved_region().end());
88 }
89
90 GCHeapSummary CollectedHeap::create_heap_summary() {
91 VirtualSpaceSummary heap_space = create_heap_space_summary();
92 return GCHeapSummary(heap_space, used());
93 }
94
95 MetaspaceSummary CollectedHeap::create_metaspace_summary() {
96 const MetaspaceSizes meta_space(
97 MetaspaceAux::committed_bytes(),
98 MetaspaceAux::used_bytes(),
99 MetaspaceAux::reserved_bytes());
100 const MetaspaceSizes data_space(
101 MetaspaceAux::committed_bytes(Metaspace::NonClassType),
102 MetaspaceAux::used_bytes(Metaspace::NonClassType),
103 MetaspaceAux::reserved_bytes(Metaspace::NonClassType));
104 const MetaspaceSizes class_space(
105 MetaspaceAux::committed_bytes(Metaspace::ClassType),
106 MetaspaceAux::used_bytes(Metaspace::ClassType),
107 MetaspaceAux::reserved_bytes(Metaspace::ClassType));
108
109 const MetaspaceChunkFreeListSummary& ms_chunk_free_list_summary =
110 MetaspaceAux::chunk_free_list_summary(Metaspace::NonClassType);
111 const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary =
112 MetaspaceAux::chunk_free_list_summary(Metaspace::ClassType);
113
114 return MetaspaceSummary(MetaspaceGC::capacity_until_GC(), meta_space, data_space, class_space,
115 ms_chunk_free_list_summary, class_chunk_free_list_summary);
116 }
117
118 void CollectedHeap::print_heap_before_gc() {
119 Universe::print_heap_before_gc();
120 if (_gc_heap_log != NULL) {
121 _gc_heap_log->log_heap_before(this);
122 }
123 }
124
125 void CollectedHeap::print_heap_after_gc() {
126 Universe::print_heap_after_gc();
127 if (_gc_heap_log != NULL) {
128 _gc_heap_log->log_heap_after(this);
129 }
130 }
131
132 void CollectedHeap::print_on_error(outputStream* st) const {
133 st->print_cr("Heap:");
134 print_extended_on(st);
135 st->cr();
136
137 _barrier_set->print_on(st);
138 }
139
140 void CollectedHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
141 const GCHeapSummary& heap_summary = create_heap_summary();
142 gc_tracer->report_gc_heap_summary(when, heap_summary);
143
144 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
145 gc_tracer->report_metaspace_summary(when, metaspace_summary);
146 }
147
148 void CollectedHeap::trace_heap_before_gc(const GCTracer* gc_tracer) {
149 trace_heap(GCWhen::BeforeGC, gc_tracer);
150 }
151
152 void CollectedHeap::trace_heap_after_gc(const GCTracer* gc_tracer) {
153 trace_heap(GCWhen::AfterGC, gc_tracer);
154 }
155
156 // WhiteBox API support for concurrent collectors. These are the
157 // default implementations, for collectors which don't support this
158 // feature.
159 bool CollectedHeap::supports_concurrent_phase_control() const {
160 return false;
161 }
162
163 const char* const* CollectedHeap::concurrent_phases() const {
164 static const char* const result[] = { NULL };
165 return result;
166 }
167
168 bool CollectedHeap::request_concurrent_phase(const char* phase) {
169 return false;
170 }
171
172 // Memory state functions.
173
174
175 CollectedHeap::CollectedHeap() :
176 _barrier_set(NULL),
177 _is_gc_active(false),
178 _total_collections(0),
179 _total_full_collections(0),
180 _gc_cause(GCCause::_no_gc),
181 _gc_lastcause(GCCause::_no_gc),
182 _defer_initial_card_mark(false) // strengthened by subclass in pre_initialize() below.
183 {
184 const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT));
185 const size_t elements_per_word = HeapWordSize / sizeof(jint);
186 _filler_array_max_size = align_object_size(filler_array_hdr_size() +
187 max_len / elements_per_word);
188
189 NOT_PRODUCT(_promotion_failure_alot_count = 0;)
190 NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;)
191
192 if (UsePerfData) {
193 EXCEPTION_MARK;
194
195 // create the gc cause jvmstat counters
196 _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause",
197 80, GCCause::to_string(_gc_cause), CHECK);
198
199 _perf_gc_lastcause =
200 PerfDataManager::create_string_variable(SUN_GC, "lastCause",
201 80, GCCause::to_string(_gc_lastcause), CHECK);
202 }
203
204 // Create the ring log
205 if (LogEvents) {
206 _gc_heap_log = new GCHeapLog();
207 } else {
208 _gc_heap_log = NULL;
209 }
210 }
211
212 // This interface assumes that it's being called by the
213 // vm thread. It collects the heap assuming that the
214 // heap lock is already held and that we are executing in
215 // the context of the vm thread.
216 void CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
217 assert(Thread::current()->is_VM_thread(), "Precondition#1");
218 assert(Heap_lock->is_locked(), "Precondition#2");
219 GCCauseSetter gcs(this, cause);
220 switch (cause) {
221 case GCCause::_heap_inspection:
222 case GCCause::_heap_dump:
223 case GCCause::_metadata_GC_threshold : {
224 HandleMark hm;
225 do_full_collection(false); // don't clear all soft refs
226 break;
227 }
228 case GCCause::_metadata_GC_clear_soft_refs: {
229 HandleMark hm;
230 do_full_collection(true); // do clear all soft refs
231 break;
232 }
233 default:
234 ShouldNotReachHere(); // Unexpected use of this function
235 }
236 }
237
238 void CollectedHeap::set_barrier_set(BarrierSet* barrier_set) {
239 _barrier_set = barrier_set;
240 BarrierSet::set_bs(barrier_set);
241 }
242
243 void CollectedHeap::pre_initialize() {
244 // Used for ReduceInitialCardMarks (when COMPILER2 is used);
245 // otherwise remains unused.
246 #if COMPILER2_OR_JVMCI
247 _defer_initial_card_mark = is_server_compilation_mode_vm() && ReduceInitialCardMarks && can_elide_tlab_store_barriers()
248 && (DeferInitialCardMark || card_mark_must_follow_store());
249 #else
250 assert(_defer_initial_card_mark == false, "Who would set it?");
251 #endif
252 }
253
254 #ifndef PRODUCT
255 void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) {
256 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
257 for (size_t slot = 0; slot < size; slot += 1) {
258 assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal),
259 "Found badHeapWordValue in post-allocation check");
260 }
261 }
262 }
263
264 void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size) {
265 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
266 for (size_t slot = 0; slot < size; slot += 1) {
267 assert((*(intptr_t*) (addr + slot)) == ((intptr_t) badHeapWordVal),
268 "Found non badHeapWordValue in pre-allocation check");
269 }
270 }
271 }
272 #endif // PRODUCT
273
274 #ifdef ASSERT
275 void CollectedHeap::check_for_valid_allocation_state() {
276 Thread *thread = Thread::current();
277 // How to choose between a pending exception and a potential
278 // OutOfMemoryError? Don't allow pending exceptions.
279 // This is a VM policy failure, so how do we exhaustively test it?
280 assert(!thread->has_pending_exception(),
281 "shouldn't be allocating with pending exception");
282 if (StrictSafepointChecks) {
283 assert(thread->allow_allocation(),
284 "Allocation done by thread for which allocation is blocked "
285 "by No_Allocation_Verifier!");
286 // Allocation of an oop can always invoke a safepoint,
287 // hence, the true argument
288 thread->check_for_valid_safepoint_state(true);
289 }
290 }
291 #endif
292
293
294 void CollectedHeap::sample_allocation(Thread* thread, HeapWord* obj,
295 size_t size, size_t overflowed_words) {
296 // Object is allocated, sample it now.
297 HeapMonitoring::object_alloc_do_sample(thread,
298 reinterpret_cast<oopDesc*>(obj),
299 size * HeapWordSize);
300 // Pick a next sample in this case, we allocated right.
301 thread->tlab().pick_next_sample(overflowed_words);
302 }
303
304 HeapWord* CollectedHeap::allocate_sampled_object(Thread* thread, size_t size) {
305 thread->tlab().set_back_actual_end();
306
307 // The tlab could still have space after this sample.
308 return thread->tlab().allocate(size);
309 }
310
311 HeapWord* CollectedHeap::allocate_from_tlab_slow(Klass* klass, Thread* thread, size_t size) {
312 // In case the tlab changes, remember if this one wanted a sample.
313 bool should_sample = HeapMonitoring::enabled() && thread->tlab().should_sample();
314
315 HeapWord* obj = NULL;
316 if (should_sample) {
317 // Remember the tlab end to fix up the sampling rate.
318 HeapWord* tlab_old_end = thread->tlab().end();
319 obj = allocate_sampled_object(thread, size);
320
321 // If we did allocate in this tlab, sample it. Otherwise, we wait for the
322 // new tlab's first allocation at the end of this method.
323 if (obj != NULL) {
324 // Fix sample rate by removing the extra words allocated in this last
325 // sample.
326 size_t overflowed_words = pointer_delta(thread->tlab().top(), tlab_old_end);
327 sample_allocation(thread, obj, size, overflowed_words);
328 return obj;
329 }
330 }
331
332 // Retain tlab and allocate object in shared space if
333 // the amount free in the tlab is too large to discard.
334 if (thread->tlab().free() > thread->tlab().refill_waste_limit()) {
335 thread->tlab().record_slow_allocation(size);
336 return NULL;
337 }
338
339 // Discard tlab and allocate a new one.
340 // To minimize fragmentation, the last TLAB may be smaller than the rest.
341 size_t new_tlab_size = thread->tlab().compute_size(size);
342
343 thread->tlab().clear_before_allocation();
344
345 if (new_tlab_size == 0) {
346 return NULL;
347 }
348
349 // Allocate a new TLAB...
350 obj = Universe::heap()->allocate_new_tlab(new_tlab_size);
351 if (obj == NULL) {
352 return NULL;
353 }
354
355 AllocTracer::send_allocation_in_new_tlab(klass, obj, new_tlab_size * HeapWordSize, size * HeapWordSize, thread);
356
357 if (ZeroTLAB) {
358 // ..and clear it.
359 Copy::zero_to_words(obj, new_tlab_size);
360 } else {
361 // ...and zap just allocated object.
362 #ifdef ASSERT
363 // Skip mangling the space corresponding to the object header to
364 // ensure that the returned space is not considered parsable by
365 // any concurrent GC thread.
366 size_t hdr_size = oopDesc::header_size();
367 Copy::fill_to_words(obj + hdr_size, new_tlab_size - hdr_size, badHeapWordVal);
368 #endif // ASSERT
369 }
370 thread->tlab().fill(obj, obj + size, new_tlab_size);
371
372 // Did we initially want to sample?
373 if (should_sample) {
374 sample_allocation(thread, obj, size);
375 }
376 return obj;
377 }
378
379 void CollectedHeap::flush_deferred_store_barrier(JavaThread* thread) {
380 MemRegion deferred = thread->deferred_card_mark();
381 if (!deferred.is_empty()) {
382 assert(_defer_initial_card_mark, "Otherwise should be empty");
383 {
384 // Verify that the storage points to a parsable object in heap
385 DEBUG_ONLY(oop old_obj = oop(deferred.start());)
386 assert(is_in(old_obj), "Not in allocated heap");
387 assert(!can_elide_initializing_store_barrier(old_obj),
388 "Else should have been filtered in new_store_pre_barrier()");
389 assert(oopDesc::is_oop(old_obj, true), "Not an oop");
390 assert(deferred.word_size() == (size_t)(old_obj->size()),
391 "Mismatch: multiple objects?");
392 }
393 BarrierSet* bs = barrier_set();
394 bs->write_region(deferred);
395 // "Clear" the deferred_card_mark field
396 thread->set_deferred_card_mark(MemRegion());
397 }
398 assert(thread->deferred_card_mark().is_empty(), "invariant");
399 }
400
401 size_t CollectedHeap::max_tlab_size() const {
402 // TLABs can't be bigger than we can fill with a int[Integer.MAX_VALUE].
403 // This restriction could be removed by enabling filling with multiple arrays.
404 // If we compute that the reasonable way as
405 // header_size + ((sizeof(jint) * max_jint) / HeapWordSize)
406 // we'll overflow on the multiply, so we do the divide first.
407 // We actually lose a little by dividing first,
408 // but that just makes the TLAB somewhat smaller than the biggest array,
409 // which is fine, since we'll be able to fill that.
410 size_t max_int_size = typeArrayOopDesc::header_size(T_INT) +
411 sizeof(jint) *
412 ((juint) max_jint / (size_t) HeapWordSize);
413 return align_down(max_int_size, MinObjAlignment);
414 }
415
416 // Helper for ReduceInitialCardMarks. For performance,
417 // compiled code may elide card-marks for initializing stores
418 // to a newly allocated object along the fast-path. We
419 // compensate for such elided card-marks as follows:
420 // (a) Generational, non-concurrent collectors, such as
421 // GenCollectedHeap(ParNew,DefNew,Tenured) and
422 // ParallelScavengeHeap(ParallelGC, ParallelOldGC)
423 // need the card-mark if and only if the region is
424 // in the old gen, and do not care if the card-mark
425 // succeeds or precedes the initializing stores themselves,
426 // so long as the card-mark is completed before the next
427 // scavenge. For all these cases, we can do a card mark
428 // at the point at which we do a slow path allocation
429 // in the old gen, i.e. in this call.
430 // (b) GenCollectedHeap(ConcurrentMarkSweepGeneration) requires
431 // in addition that the card-mark for an old gen allocated
432 // object strictly follow any associated initializing stores.
433 // In these cases, the memRegion remembered below is
434 // used to card-mark the entire region either just before the next
435 // slow-path allocation by this thread or just before the next scavenge or
436 // CMS-associated safepoint, whichever of these events happens first.
437 // (The implicit assumption is that the object has been fully
438 // initialized by this point, a fact that we assert when doing the
439 // card-mark.)
440 // (c) G1CollectedHeap(G1) uses two kinds of write barriers. When a
441 // G1 concurrent marking is in progress an SATB (pre-write-)barrier
442 // is used to remember the pre-value of any store. Initializing
443 // stores will not need this barrier, so we need not worry about
444 // compensating for the missing pre-barrier here. Turning now
445 // to the post-barrier, we note that G1 needs a RS update barrier
446 // which simply enqueues a (sequence of) dirty cards which may
447 // optionally be refined by the concurrent update threads. Note
448 // that this barrier need only be applied to a non-young write,
449 // but, like in CMS, because of the presence of concurrent refinement
450 // (much like CMS' precleaning), must strictly follow the oop-store.
451 // Thus, using the same protocol for maintaining the intended
452 // invariants turns out, serendepitously, to be the same for both
453 // G1 and CMS.
454 //
455 // For any future collector, this code should be reexamined with
456 // that specific collector in mind, and the documentation above suitably
457 // extended and updated.
458 oop CollectedHeap::new_store_pre_barrier(JavaThread* thread, oop new_obj) {
459 // If a previous card-mark was deferred, flush it now.
460 flush_deferred_store_barrier(thread);
461 if (can_elide_initializing_store_barrier(new_obj) ||
462 new_obj->is_typeArray()) {
463 // Arrays of non-references don't need a pre-barrier.
464 // The deferred_card_mark region should be empty
465 // following the flush above.
466 assert(thread->deferred_card_mark().is_empty(), "Error");
467 } else {
468 MemRegion mr((HeapWord*)new_obj, new_obj->size());
469 assert(!mr.is_empty(), "Error");
470 if (_defer_initial_card_mark) {
471 // Defer the card mark
472 thread->set_deferred_card_mark(mr);
473 } else {
474 // Do the card mark
475 BarrierSet* bs = barrier_set();
476 bs->write_region(mr);
477 }
478 }
479 return new_obj;
480 }
481
482 size_t CollectedHeap::filler_array_hdr_size() {
483 return align_object_offset(arrayOopDesc::header_size(T_INT)); // align to Long
484 }
485
486 size_t CollectedHeap::filler_array_min_size() {
487 return align_object_size(filler_array_hdr_size()); // align to MinObjAlignment
488 }
489
490 #ifdef ASSERT
491 void CollectedHeap::fill_args_check(HeapWord* start, size_t words)
492 {
493 assert(words >= min_fill_size(), "too small to fill");
494 assert(is_object_aligned(words), "unaligned size");
495 assert(Universe::heap()->is_in_reserved(start), "not in heap");
496 assert(Universe::heap()->is_in_reserved(start + words - 1), "not in heap");
497 }
498
499 void CollectedHeap::zap_filler_array(HeapWord* start, size_t words, bool zap)
500 {
501 if (ZapFillerObjects && zap) {
502 Copy::fill_to_words(start + filler_array_hdr_size(),
503 words - filler_array_hdr_size(), 0XDEAFBABE);
504 }
505 }
506 #endif // ASSERT
507
508 void
509 CollectedHeap::fill_with_array(HeapWord* start, size_t words, bool zap)
510 {
511 assert(words >= filler_array_min_size(), "too small for an array");
512 assert(words <= filler_array_max_size(), "too big for a single object");
513
514 const size_t payload_size = words - filler_array_hdr_size();
515 const size_t len = payload_size * HeapWordSize / sizeof(jint);
516 assert((int)len >= 0, "size too large " SIZE_FORMAT " becomes %d", words, (int)len);
517
518 // Set the length first for concurrent GC.
519 ((arrayOop)start)->set_length((int)len);
520 post_allocation_setup_common(Universe::intArrayKlassObj(), start);
521 DEBUG_ONLY(zap_filler_array(start, words, zap);)
522 }
523
524 void
525 CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words, bool zap)
526 {
527 assert(words <= filler_array_max_size(), "too big for a single object");
528
529 if (words >= filler_array_min_size()) {
530 fill_with_array(start, words, zap);
531 } else if (words > 0) {
532 assert(words == min_fill_size(), "unaligned size");
533 post_allocation_setup_common(SystemDictionary::Object_klass(), start);
534 }
535 }
536
537 void CollectedHeap::fill_with_object(HeapWord* start, size_t words, bool zap)
538 {
539 DEBUG_ONLY(fill_args_check(start, words);)
540 HandleMark hm; // Free handles before leaving.
541 fill_with_object_impl(start, words, zap);
542 }
543
544 void CollectedHeap::fill_with_objects(HeapWord* start, size_t words, bool zap)
545 {
546 DEBUG_ONLY(fill_args_check(start, words);)
547 HandleMark hm; // Free handles before leaving.
548
549 // Multiple objects may be required depending on the filler array maximum size. Fill
550 // the range up to that with objects that are filler_array_max_size sized. The
551 // remainder is filled with a single object.
552 const size_t min = min_fill_size();
553 const size_t max = filler_array_max_size();
554 while (words > max) {
555 const size_t cur = (words - max) >= min ? max : max - min;
556 fill_with_array(start, cur, zap);
557 start += cur;
558 words -= cur;
559 }
560
561 fill_with_object_impl(start, words, zap);
562 }
563
564 HeapWord* CollectedHeap::allocate_new_tlab(size_t size) {
565 guarantee(false, "thread-local allocation buffers not supported");
566 return NULL;
567 }
568
569 void CollectedHeap::ensure_parsability(bool retire_tlabs) {
570 // The second disjunct in the assertion below makes a concession
571 // for the start-up verification done while the VM is being
572 // created. Callers be careful that you know that mutators
573 // aren't going to interfere -- for instance, this is permissible
574 // if we are still single-threaded and have either not yet
575 // started allocating (nothing much to verify) or we have
576 // started allocating but are now a full-fledged JavaThread
577 // (and have thus made our TLAB's) available for filling.
578 assert(SafepointSynchronize::is_at_safepoint() ||
579 !is_init_completed(),
580 "Should only be called at a safepoint or at start-up"
581 " otherwise concurrent mutator activity may make heap "
582 " unparsable again");
583 const bool use_tlab = UseTLAB;
584 const bool deferred = _defer_initial_card_mark;
585 // The main thread starts allocating via a TLAB even before it
586 // has added itself to the threads list at vm boot-up.
587 JavaThreadIteratorWithHandle jtiwh;
588 assert(!use_tlab || jtiwh.length() > 0,
589 "Attempt to fill tlabs before main thread has been added"
590 " to threads list is doomed to failure!");
591 for (; JavaThread *thread = jtiwh.next(); ) {
592 if (use_tlab) thread->tlab().make_parsable(retire_tlabs);
593 #if COMPILER2_OR_JVMCI
594 // The deferred store barriers must all have been flushed to the
595 // card-table (or other remembered set structure) before GC starts
596 // processing the card-table (or other remembered set).
597 if (deferred) flush_deferred_store_barrier(thread);
598 #else
599 assert(!deferred, "Should be false");
600 assert(thread->deferred_card_mark().is_empty(), "Should be empty");
601 #endif
602 }
603 }
604
605 void CollectedHeap::accumulate_statistics_all_tlabs() {
606 if (UseTLAB) {
607 assert(SafepointSynchronize::is_at_safepoint() ||
608 !is_init_completed(),
609 "should only accumulate statistics on tlabs at safepoint");
610
611 ThreadLocalAllocBuffer::accumulate_statistics_before_gc();
612 }
613 }
614
615 void CollectedHeap::resize_all_tlabs() {
616 if (UseTLAB) {
617 assert(SafepointSynchronize::is_at_safepoint() ||
618 !is_init_completed(),
619 "should only resize tlabs at safepoint");
620
621 ThreadLocalAllocBuffer::resize_all_tlabs();
622 }
623 }
624
625 void CollectedHeap::full_gc_dump(GCTimer* timer, bool before) {
626 assert(timer != NULL, "timer is null");
627 if ((HeapDumpBeforeFullGC && before) || (HeapDumpAfterFullGC && !before)) {
628 GCTraceTime(Info, gc) tm(before ? "Heap Dump (before full gc)" : "Heap Dump (after full gc)", timer);
629 HeapDumper::dump_heap();
630 }
631
632 LogTarget(Trace, gc, classhisto) lt;
633 if (lt.is_enabled()) {
634 GCTraceTime(Trace, gc, classhisto) tm(before ? "Class Histogram (before full gc)" : "Class Histogram (after full gc)", timer);
635 ResourceMark rm;
636 LogStream ls(lt);
637 VM_GC_HeapInspection inspector(&ls, false /* ! full gc */);
638 inspector.doit();
639 }
640 }
641
642 void CollectedHeap::pre_full_gc_dump(GCTimer* timer) {
643 full_gc_dump(timer, true);
644 }
645
646 void CollectedHeap::post_full_gc_dump(GCTimer* timer) {
647 full_gc_dump(timer, false);
648 }
649
650 void CollectedHeap::initialize_reserved_region(HeapWord *start, HeapWord *end) {
651 // It is important to do this in a way such that concurrent readers can't
652 // temporarily think something is in the heap. (Seen this happen in asserts.)
653 _reserved.set_word_size(0);
654 _reserved.set_start(start);
655 _reserved.set_end(end);
656 }
657
658 void CollectedHeap::post_initialize() {
659 initialize_serviceability();
660 }