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