1 /*
2 * Copyright (c) 2001, 2016, 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/init.hpp"
42 #include "runtime/thread.inline.hpp"
43 #include "services/heapDumper.hpp"
44
45
46 #ifdef ASSERT
47 int CollectedHeap::_fire_out_of_memory_count = 0;
48 #endif
49
50 size_t CollectedHeap::_filler_array_max_size = 0;
51
52 template <>
53 void EventLogBase<GCMessage>::print(outputStream* st, GCMessage& m) {
54 st->print_cr("GC heap %s", m.is_before ? "before" : "after");
55 st->print_raw(m);
56 }
57
58 void GCHeapLog::log_heap(CollectedHeap* heap, bool before) {
59 if (!should_log()) {
60 return;
61 }
62
63 double timestamp = fetch_timestamp();
64 MutexLockerEx ml(&_mutex, Mutex::_no_safepoint_check_flag);
65 int index = compute_log_index();
66 _records[index].thread = NULL; // Its the GC thread so it's not that interesting.
67 _records[index].timestamp = timestamp;
68 _records[index].data.is_before = before;
69 stringStream st(_records[index].data.buffer(), _records[index].data.size());
70
71 st.print_cr("{Heap %s GC invocations=%u (full %u):",
72 before ? "before" : "after",
73 heap->total_collections(),
74 heap->total_full_collections());
75
76 heap->print_on(&st);
77 st.print_cr("}");
78 }
79
80 VirtualSpaceSummary CollectedHeap::create_heap_space_summary() {
81 size_t capacity_in_words = capacity() / HeapWordSize;
82
83 return VirtualSpaceSummary(
84 reserved_region().start(), reserved_region().start() + capacity_in_words, reserved_region().end());
85 }
86
87 GCHeapSummary CollectedHeap::create_heap_summary() {
88 VirtualSpaceSummary heap_space = create_heap_space_summary();
89 return GCHeapSummary(heap_space, used());
90 }
91
92 MetaspaceSummary CollectedHeap::create_metaspace_summary() {
93 const MetaspaceSizes meta_space(
94 MetaspaceAux::committed_bytes(),
95 MetaspaceAux::used_bytes(),
96 MetaspaceAux::reserved_bytes());
97 const MetaspaceSizes data_space(
98 MetaspaceAux::committed_bytes(Metaspace::NonClassType),
99 MetaspaceAux::used_bytes(Metaspace::NonClassType),
100 MetaspaceAux::reserved_bytes(Metaspace::NonClassType));
101 const MetaspaceSizes class_space(
102 MetaspaceAux::committed_bytes(Metaspace::ClassType),
103 MetaspaceAux::used_bytes(Metaspace::ClassType),
104 MetaspaceAux::reserved_bytes(Metaspace::ClassType));
105
106 const MetaspaceChunkFreeListSummary& ms_chunk_free_list_summary =
107 MetaspaceAux::chunk_free_list_summary(Metaspace::NonClassType);
108 const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary =
109 MetaspaceAux::chunk_free_list_summary(Metaspace::ClassType);
110
111 return MetaspaceSummary(MetaspaceGC::capacity_until_GC(), meta_space, data_space, class_space,
112 ms_chunk_free_list_summary, class_chunk_free_list_summary);
113 }
114
115 void CollectedHeap::print_heap_before_gc() {
116 Universe::print_heap_before_gc();
117 if (_gc_heap_log != NULL) {
118 _gc_heap_log->log_heap_before(this);
119 }
120 }
121
122 void CollectedHeap::print_heap_after_gc() {
123 Universe::print_heap_after_gc();
124 if (_gc_heap_log != NULL) {
125 _gc_heap_log->log_heap_after(this);
126 }
127 }
128
129 void CollectedHeap::print_on_error(outputStream* st) const {
130 st->print_cr("Heap:");
131 print_extended_on(st);
132 st->cr();
133
134 _barrier_set->print_on(st);
135 }
136
137 void CollectedHeap::register_nmethod(nmethod* nm) {
138 assert_locked_or_safepoint(CodeCache_lock);
139 }
140
141 void CollectedHeap::unregister_nmethod(nmethod* nm) {
142 assert_locked_or_safepoint(CodeCache_lock);
143 }
144
145 void CollectedHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
146 const GCHeapSummary& heap_summary = create_heap_summary();
147 gc_tracer->report_gc_heap_summary(when, heap_summary);
148
149 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
150 gc_tracer->report_metaspace_summary(when, metaspace_summary);
151 }
152
153 void CollectedHeap::trace_heap_before_gc(const GCTracer* gc_tracer) {
154 trace_heap(GCWhen::BeforeGC, gc_tracer);
155 }
156
157 void CollectedHeap::trace_heap_after_gc(const GCTracer* gc_tracer) {
158 trace_heap(GCWhen::AfterGC, gc_tracer);
159 }
160
161 // Memory state functions.
162
163
164 CollectedHeap::CollectedHeap() :
165 _barrier_set(NULL),
166 _is_gc_active(false),
167 _total_collections(0),
168 _total_full_collections(0),
169 _gc_cause(GCCause::_no_gc),
170 _gc_lastcause(GCCause::_no_gc),
171 _defer_initial_card_mark(false) // strengthened by subclass in pre_initialize() below.
172 {
173 const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT));
174 const size_t elements_per_word = HeapWordSize / sizeof(jint);
175 _filler_array_max_size = align_object_size(filler_array_hdr_size() +
176 max_len / elements_per_word);
177
178 NOT_PRODUCT(_promotion_failure_alot_count = 0;)
179 NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;)
180
181 if (UsePerfData) {
182 EXCEPTION_MARK;
183
184 // create the gc cause jvmstat counters
185 _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause",
186 80, GCCause::to_string(_gc_cause), CHECK);
187
188 _perf_gc_lastcause =
189 PerfDataManager::create_string_variable(SUN_GC, "lastCause",
190 80, GCCause::to_string(_gc_lastcause), CHECK);
191 }
192
193 // Create the ring log
194 if (LogEvents) {
195 _gc_heap_log = new GCHeapLog();
196 } else {
197 _gc_heap_log = NULL;
198 }
199 }
200
201 // This interface assumes that it's being called by the
202 // vm thread. It collects the heap assuming that the
203 // heap lock is already held and that we are executing in
204 // the context of the vm thread.
205 void CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
206 assert(Thread::current()->is_VM_thread(), "Precondition#1");
207 assert(Heap_lock->is_locked(), "Precondition#2");
208 GCCauseSetter gcs(this, cause);
209 switch (cause) {
210 case GCCause::_heap_inspection:
211 case GCCause::_heap_dump:
212 case GCCause::_metadata_GC_threshold : {
213 HandleMark hm;
214 do_full_collection(false); // don't clear all soft refs
215 break;
216 }
217 case GCCause::_metadata_GC_clear_soft_refs: {
218 HandleMark hm;
219 do_full_collection(true); // do clear all soft refs
220 break;
221 }
222 default:
223 ShouldNotReachHere(); // Unexpected use of this function
224 }
225 }
226
227 void CollectedHeap::set_barrier_set(BarrierSet* barrier_set) {
228 _barrier_set = barrier_set;
229 oopDesc::set_bs(_barrier_set);
230 }
231
232 void CollectedHeap::pre_initialize() {
233 // Used for ReduceInitialCardMarks (when COMPILER2 is used);
234 // otherwise remains unused.
235 #if defined(COMPILER2) || INCLUDE_JVMCI
236 _defer_initial_card_mark = ReduceInitialCardMarks && can_elide_tlab_store_barriers()
237 && (DeferInitialCardMark || card_mark_must_follow_store());
238 #else
239 assert(_defer_initial_card_mark == false, "Who would set it?");
240 #endif
241 }
242
243 #ifndef PRODUCT
244 void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) {
245 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
246 for (size_t slot = 0; slot < size; slot += 1) {
247 assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal),
248 "Found badHeapWordValue in post-allocation check");
249 }
250 }
251 }
252
253 void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size) {
254 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
255 for (size_t slot = 0; slot < size; slot += 1) {
256 assert((*(intptr_t*) (addr + slot)) == ((intptr_t) badHeapWordVal),
257 "Found non badHeapWordValue in pre-allocation check");
258 }
259 }
260 }
261 #endif // PRODUCT
262
263 #ifdef ASSERT
264 void CollectedHeap::check_for_valid_allocation_state() {
265 Thread *thread = Thread::current();
266 // How to choose between a pending exception and a potential
267 // OutOfMemoryError? Don't allow pending exceptions.
268 // This is a VM policy failure, so how do we exhaustively test it?
269 assert(!thread->has_pending_exception(),
270 "shouldn't be allocating with pending exception");
271 if (StrictSafepointChecks) {
272 assert(thread->allow_allocation(),
273 "Allocation done by thread for which allocation is blocked "
274 "by No_Allocation_Verifier!");
275 // Allocation of an oop can always invoke a safepoint,
276 // hence, the true argument
277 thread->check_for_valid_safepoint_state(true);
278 }
279 }
280 #endif
281
282 HeapWord* CollectedHeap::allocate_from_tlab_slow(KlassHandle klass, Thread* thread, size_t size) {
283
284 // Retain tlab and allocate object in shared space if
285 // the amount free in the tlab is too large to discard.
286 if (thread->tlab().free() > thread->tlab().refill_waste_limit()) {
287 thread->tlab().record_slow_allocation(size);
288 return NULL;
289 }
290
291 // Discard tlab and allocate a new one.
292 // To minimize fragmentation, the last TLAB may be smaller than the rest.
293 size_t new_tlab_size = thread->tlab().compute_size(size);
294
295 thread->tlab().clear_before_allocation();
296
297 if (new_tlab_size == 0) {
298 return NULL;
299 }
300
301 // Allocate a new TLAB...
302 HeapWord* obj = Universe::heap()->allocate_new_tlab(new_tlab_size);
303 if (obj == NULL) {
304 return NULL;
305 }
306
307 AllocTracer::send_allocation_in_new_tlab_event(klass, new_tlab_size * HeapWordSize, size * HeapWordSize);
308
309 if (ZeroTLAB) {
310 // ..and clear it.
311 Copy::zero_to_words(obj, new_tlab_size);
312 } else {
313 // ...and zap just allocated object.
314 #ifdef ASSERT
315 // Skip mangling the space corresponding to the object header to
316 // ensure that the returned space is not considered parsable by
317 // any concurrent GC thread.
318 size_t hdr_size = oopDesc::header_size();
319 Copy::fill_to_words(obj + hdr_size, new_tlab_size - hdr_size, badHeapWordVal);
320 #endif // ASSERT
321 }
322 thread->tlab().fill(obj, obj + size, new_tlab_size);
323 return obj;
324 }
325
326 void CollectedHeap::flush_deferred_store_barrier(JavaThread* thread) {
327 MemRegion deferred = thread->deferred_card_mark();
328 if (!deferred.is_empty()) {
329 assert(_defer_initial_card_mark, "Otherwise should be empty");
330 {
331 // Verify that the storage points to a parsable object in heap
332 DEBUG_ONLY(oop old_obj = oop(deferred.start());)
333 assert(is_in(old_obj), "Not in allocated heap");
334 assert(!can_elide_initializing_store_barrier(old_obj),
335 "Else should have been filtered in new_store_pre_barrier()");
336 assert(old_obj->is_oop(true), "Not an oop");
337 assert(deferred.word_size() == (size_t)(old_obj->size()),
338 "Mismatch: multiple objects?");
339 }
340 BarrierSet* bs = barrier_set();
341 assert(bs->has_write_region_opt(), "No write_region() on BarrierSet");
342 bs->write_region(deferred);
343 // "Clear" the deferred_card_mark field
344 thread->set_deferred_card_mark(MemRegion());
345 }
346 assert(thread->deferred_card_mark().is_empty(), "invariant");
347 }
348
349 size_t CollectedHeap::max_tlab_size() const {
350 // TLABs can't be bigger than we can fill with a int[Integer.MAX_VALUE].
351 // This restriction could be removed by enabling filling with multiple arrays.
352 // If we compute that the reasonable way as
353 // header_size + ((sizeof(jint) * max_jint) / HeapWordSize)
354 // we'll overflow on the multiply, so we do the divide first.
355 // We actually lose a little by dividing first,
356 // but that just makes the TLAB somewhat smaller than the biggest array,
357 // which is fine, since we'll be able to fill that.
358 size_t max_int_size = typeArrayOopDesc::header_size(T_INT) +
359 sizeof(jint) *
360 ((juint) max_jint / (size_t) HeapWordSize);
361 return align_size_down(max_int_size, MinObjAlignment);
362 }
363
364 // Helper for ReduceInitialCardMarks. For performance,
365 // compiled code may elide card-marks for initializing stores
366 // to a newly allocated object along the fast-path. We
367 // compensate for such elided card-marks as follows:
368 // (a) Generational, non-concurrent collectors, such as
369 // GenCollectedHeap(ParNew,DefNew,Tenured) and
370 // ParallelScavengeHeap(ParallelGC, ParallelOldGC)
371 // need the card-mark if and only if the region is
372 // in the old gen, and do not care if the card-mark
373 // succeeds or precedes the initializing stores themselves,
374 // so long as the card-mark is completed before the next
375 // scavenge. For all these cases, we can do a card mark
376 // at the point at which we do a slow path allocation
377 // in the old gen, i.e. in this call.
378 // (b) GenCollectedHeap(ConcurrentMarkSweepGeneration) requires
379 // in addition that the card-mark for an old gen allocated
380 // object strictly follow any associated initializing stores.
381 // In these cases, the memRegion remembered below is
382 // used to card-mark the entire region either just before the next
383 // slow-path allocation by this thread or just before the next scavenge or
384 // CMS-associated safepoint, whichever of these events happens first.
385 // (The implicit assumption is that the object has been fully
386 // initialized by this point, a fact that we assert when doing the
387 // card-mark.)
388 // (c) G1CollectedHeap(G1) uses two kinds of write barriers. When a
389 // G1 concurrent marking is in progress an SATB (pre-write-)barrier
390 // is used to remember the pre-value of any store. Initializing
391 // stores will not need this barrier, so we need not worry about
392 // compensating for the missing pre-barrier here. Turning now
393 // to the post-barrier, we note that G1 needs a RS update barrier
394 // which simply enqueues a (sequence of) dirty cards which may
395 // optionally be refined by the concurrent update threads. Note
396 // that this barrier need only be applied to a non-young write,
397 // but, like in CMS, because of the presence of concurrent refinement
398 // (much like CMS' precleaning), must strictly follow the oop-store.
399 // Thus, using the same protocol for maintaining the intended
400 // invariants turns out, serendepitously, to be the same for both
401 // G1 and CMS.
402 //
403 // For any future collector, this code should be reexamined with
404 // that specific collector in mind, and the documentation above suitably
405 // extended and updated.
406 oop CollectedHeap::new_store_pre_barrier(JavaThread* thread, oop new_obj) {
407 // If a previous card-mark was deferred, flush it now.
408 flush_deferred_store_barrier(thread);
409 if (can_elide_initializing_store_barrier(new_obj) ||
410 new_obj->is_typeArray()) {
411 // Arrays of non-references don't need a pre-barrier.
412 // The deferred_card_mark region should be empty
413 // following the flush above.
414 assert(thread->deferred_card_mark().is_empty(), "Error");
415 } else {
416 MemRegion mr((HeapWord*)new_obj, new_obj->size());
417 assert(!mr.is_empty(), "Error");
418 if (_defer_initial_card_mark) {
419 // Defer the card mark
420 thread->set_deferred_card_mark(mr);
421 } else {
422 // Do the card mark
423 BarrierSet* bs = barrier_set();
424 assert(bs->has_write_region_opt(), "No write_region() on BarrierSet");
425 bs->write_region(mr);
426 }
427 }
428 return new_obj;
429 }
430
431 size_t CollectedHeap::filler_array_hdr_size() {
432 return size_t(align_object_offset(arrayOopDesc::header_size(T_INT))); // align to Long
433 }
434
435 size_t CollectedHeap::filler_array_min_size() {
436 return align_object_size(filler_array_hdr_size()); // align to MinObjAlignment
437 }
438
439 #ifdef ASSERT
440 void CollectedHeap::fill_args_check(HeapWord* start, size_t words)
441 {
442 assert(words >= min_fill_size(), "too small to fill");
443 assert(words % MinObjAlignment == 0, "unaligned size");
444 assert(Universe::heap()->is_in_reserved(start), "not in heap");
445 assert(Universe::heap()->is_in_reserved(start + words - 1), "not in heap");
446 }
447
448 void CollectedHeap::zap_filler_array(HeapWord* start, size_t words, bool zap)
449 {
450 if (ZapFillerObjects && zap) {
451 Copy::fill_to_words(start + filler_array_hdr_size(),
452 words - filler_array_hdr_size(), 0XDEAFBABE);
453 }
454 }
455 #endif // ASSERT
456
457 void
458 CollectedHeap::fill_with_array(HeapWord* start, size_t words, bool zap)
459 {
460 assert(words >= filler_array_min_size(), "too small for an array");
461 assert(words <= filler_array_max_size(), "too big for a single object");
462
463 const size_t payload_size = words - filler_array_hdr_size();
464 const size_t len = payload_size * HeapWordSize / sizeof(jint);
465 assert((int)len >= 0, "size too large " SIZE_FORMAT " becomes %d", words, (int)len);
466
467 // Set the length first for concurrent GC.
468 ((arrayOop)start)->set_length((int)len);
469 post_allocation_setup_common(Universe::intArrayKlassObj(), start);
470 DEBUG_ONLY(zap_filler_array(start, words, zap);)
471 }
472
473 void
474 CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words, bool zap)
475 {
476 assert(words <= filler_array_max_size(), "too big for a single object");
477
478 if (words >= filler_array_min_size()) {
479 fill_with_array(start, words, zap);
480 } else if (words > 0) {
481 assert(words == min_fill_size(), "unaligned size");
482 post_allocation_setup_common(SystemDictionary::Object_klass(), start);
483 }
484 }
485
486 void CollectedHeap::fill_with_object(HeapWord* start, size_t words, bool zap)
487 {
488 DEBUG_ONLY(fill_args_check(start, words);)
489 HandleMark hm; // Free handles before leaving.
490 fill_with_object_impl(start, words, zap);
491 }
492
493 void CollectedHeap::fill_with_objects(HeapWord* start, size_t words, bool zap)
494 {
495 DEBUG_ONLY(fill_args_check(start, words);)
496 HandleMark hm; // Free handles before leaving.
497
498 // Multiple objects may be required depending on the filler array maximum size. Fill
499 // the range up to that with objects that are filler_array_max_size sized. The
500 // remainder is filled with a single object.
501 const size_t min = min_fill_size();
502 const size_t max = filler_array_max_size();
503 while (words > max) {
504 const size_t cur = (words - max) >= min ? max : max - min;
505 fill_with_array(start, cur, zap);
506 start += cur;
507 words -= cur;
508 }
509
510 fill_with_object_impl(start, words, zap);
511 }
512
513 HeapWord* CollectedHeap::allocate_new_tlab(size_t size) {
514 guarantee(false, "thread-local allocation buffers not supported");
515 return NULL;
516 }
517
518 void CollectedHeap::ensure_parsability(bool retire_tlabs) {
519 // The second disjunct in the assertion below makes a concession
520 // for the start-up verification done while the VM is being
521 // created. Callers be careful that you know that mutators
522 // aren't going to interfere -- for instance, this is permissible
523 // if we are still single-threaded and have either not yet
524 // started allocating (nothing much to verify) or we have
525 // started allocating but are now a full-fledged JavaThread
526 // (and have thus made our TLAB's) available for filling.
527 assert(SafepointSynchronize::is_at_safepoint() ||
528 !is_init_completed(),
529 "Should only be called at a safepoint or at start-up"
530 " otherwise concurrent mutator activity may make heap "
531 " unparsable again");
532 const bool use_tlab = UseTLAB;
533 const bool deferred = _defer_initial_card_mark;
534 // The main thread starts allocating via a TLAB even before it
535 // has added itself to the threads list at vm boot-up.
536 assert(!use_tlab || Threads::first() != NULL,
537 "Attempt to fill tlabs before main thread has been added"
538 " to threads list is doomed to failure!");
539 for (JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
540 if (use_tlab) thread->tlab().make_parsable(retire_tlabs);
541 #if defined(COMPILER2) || INCLUDE_JVMCI
542 // The deferred store barriers must all have been flushed to the
543 // card-table (or other remembered set structure) before GC starts
544 // processing the card-table (or other remembered set).
545 if (deferred) flush_deferred_store_barrier(thread);
546 #else
547 assert(!deferred, "Should be false");
548 assert(thread->deferred_card_mark().is_empty(), "Should be empty");
549 #endif
550 }
551 }
552
553 void CollectedHeap::accumulate_statistics_all_tlabs() {
554 if (UseTLAB) {
555 assert(SafepointSynchronize::is_at_safepoint() ||
556 !is_init_completed(),
557 "should only accumulate statistics on tlabs at safepoint");
558
559 ThreadLocalAllocBuffer::accumulate_statistics_before_gc();
560 }
561 }
562
563 void CollectedHeap::resize_all_tlabs() {
564 if (UseTLAB) {
565 assert(SafepointSynchronize::is_at_safepoint() ||
566 !is_init_completed(),
567 "should only resize tlabs at safepoint");
568
569 ThreadLocalAllocBuffer::resize_all_tlabs();
570 }
571 }
572
573 void CollectedHeap::full_gc_dump(GCTimer* timer, bool before) {
574 assert(timer != NULL, "timer is null");
575 if ((HeapDumpBeforeFullGC && before) || (HeapDumpAfterFullGC && !before)) {
576 GCTraceTime(Info, gc) tm(before ? "Heap Dump (before full gc)" : "Heap Dump (after full gc)", timer);
577 HeapDumper::dump_heap();
578 }
579
580 Log(gc, classhisto) log;
581 if (log.is_trace()) {
582 GCTraceTime(Trace, gc, classhisto) tm(before ? "Class Histogram (before full gc)" : "Class Histogram (after full gc)", timer);
583 ResourceMark rm;
584 VM_GC_HeapInspection inspector(log.trace_stream(), false /* ! full gc */);
585 inspector.doit();
586 }
587 }
588
589 void CollectedHeap::pre_full_gc_dump(GCTimer* timer) {
590 full_gc_dump(timer, true);
591 }
592
593 void CollectedHeap::post_full_gc_dump(GCTimer* timer) {
594 full_gc_dump(timer, false);
595 }
596
597 void CollectedHeap::initialize_reserved_region(HeapWord *start, HeapWord *end) {
598 // It is important to do this in a way such that concurrent readers can't
599 // temporarily think something is in the heap. (Seen this happen in asserts.)
600 _reserved.set_word_size(0);
601 _reserved.set_start(start);
602 _reserved.set_end(end);
603 }
604
605 /////////////// Unit tests ///////////////
606
607 #ifndef PRODUCT
608 void CollectedHeap::test_is_in() {
609 CollectedHeap* heap = Universe::heap();
610
611 uintptr_t epsilon = (uintptr_t) MinObjAlignment;
612 uintptr_t heap_start = (uintptr_t) heap->_reserved.start();
613 uintptr_t heap_end = (uintptr_t) heap->_reserved.end();
614
615 // Test that NULL is not in the heap.
616 assert(!heap->is_in(NULL), "NULL is unexpectedly in the heap");
617
618 // Test that a pointer to before the heap start is reported as outside the heap.
619 assert(heap_start >= ((uintptr_t)NULL + epsilon), "sanity");
620 void* before_heap = (void*)(heap_start - epsilon);
621 assert(!heap->is_in(before_heap),
622 "before_heap: " PTR_FORMAT " is unexpectedly in the heap", p2i(before_heap));
623
624 // Test that a pointer to after the heap end is reported as outside the heap.
625 assert(heap_end <= ((uintptr_t)-1 - epsilon), "sanity");
626 void* after_heap = (void*)(heap_end + epsilon);
627 assert(!heap->is_in(after_heap),
628 "after_heap: " PTR_FORMAT " is unexpectedly in the heap", p2i(after_heap));
629 }
630
631 void CollectedHeap_test() {
632 CollectedHeap::test_is_in();
633 }
634 #endif