collectedHeap.cpp revision 13249:a2753984d2c1
13229Spst/* 250476Speter * Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved. 33229Spst * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 43229Spst * 59720Swpaul * This code is free software; you can redistribute it and/or modify it 63229Spst * under the terms of the GNU General Public License version 2 only, as 73229Spst * published by the Free Software Foundation. 8201380Sed * 9201380Sed * This code is distributed in the hope that it will be useful, but WITHOUT 1013575Spst * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 113229Spst * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 123229Spst * version 2 for more details (a copy is included in the LICENSE file that 133229Spst * accompanied this code). 143229Spst * 1574814Sru * You should have received a copy of the GNU General Public License version 1613849Smpp * 2 along with this work; if not, write to the Free Software Foundation, 173229Spst * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 183229Spst * 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#include "utilities/align.hpp" 45 46 47#ifdef ASSERT 48int CollectedHeap::_fire_out_of_memory_count = 0; 49#endif 50 51size_t CollectedHeap::_filler_array_max_size = 0; 52 53template <> 54void EventLogBase<GCMessage>::print(outputStream* st, GCMessage& m) { 55 st->print_cr("GC heap %s", m.is_before ? "before" : "after"); 56 st->print_raw(m); 57} 58 59void GCHeapLog::log_heap(CollectedHeap* heap, bool before) { 60 if (!should_log()) { 61 return; 62 } 63 64 double timestamp = fetch_timestamp(); 65 MutexLockerEx ml(&_mutex, Mutex::_no_safepoint_check_flag); 66 int index = compute_log_index(); 67 _records[index].thread = NULL; // Its the GC thread so it's not that interesting. 68 _records[index].timestamp = timestamp; 69 _records[index].data.is_before = before; 70 stringStream st(_records[index].data.buffer(), _records[index].data.size()); 71 72 st.print_cr("{Heap %s GC invocations=%u (full %u):", 73 before ? "before" : "after", 74 heap->total_collections(), 75 heap->total_full_collections()); 76 77 heap->print_on(&st); 78 st.print_cr("}"); 79} 80 81VirtualSpaceSummary CollectedHeap::create_heap_space_summary() { 82 size_t capacity_in_words = capacity() / HeapWordSize; 83 84 return VirtualSpaceSummary( 85 reserved_region().start(), reserved_region().start() + capacity_in_words, reserved_region().end()); 86} 87 88GCHeapSummary CollectedHeap::create_heap_summary() { 89 VirtualSpaceSummary heap_space = create_heap_space_summary(); 90 return GCHeapSummary(heap_space, used()); 91} 92 93MetaspaceSummary CollectedHeap::create_metaspace_summary() { 94 const MetaspaceSizes meta_space( 95 MetaspaceAux::committed_bytes(), 96 MetaspaceAux::used_bytes(), 97 MetaspaceAux::reserved_bytes()); 98 const MetaspaceSizes data_space( 99 MetaspaceAux::committed_bytes(Metaspace::NonClassType), 100 MetaspaceAux::used_bytes(Metaspace::NonClassType), 101 MetaspaceAux::reserved_bytes(Metaspace::NonClassType)); 102 const MetaspaceSizes class_space( 103 MetaspaceAux::committed_bytes(Metaspace::ClassType), 104 MetaspaceAux::used_bytes(Metaspace::ClassType), 105 MetaspaceAux::reserved_bytes(Metaspace::ClassType)); 106 107 const MetaspaceChunkFreeListSummary& ms_chunk_free_list_summary = 108 MetaspaceAux::chunk_free_list_summary(Metaspace::NonClassType); 109 const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary = 110 MetaspaceAux::chunk_free_list_summary(Metaspace::ClassType); 111 112 return MetaspaceSummary(MetaspaceGC::capacity_until_GC(), meta_space, data_space, class_space, 113 ms_chunk_free_list_summary, class_chunk_free_list_summary); 114} 115 116void CollectedHeap::print_heap_before_gc() { 117 Universe::print_heap_before_gc(); 118 if (_gc_heap_log != NULL) { 119 _gc_heap_log->log_heap_before(this); 120 } 121} 122 123void CollectedHeap::print_heap_after_gc() { 124 Universe::print_heap_after_gc(); 125 if (_gc_heap_log != NULL) { 126 _gc_heap_log->log_heap_after(this); 127 } 128} 129 130void CollectedHeap::print_on_error(outputStream* st) const { 131 st->print_cr("Heap:"); 132 print_extended_on(st); 133 st->cr(); 134 135 _barrier_set->print_on(st); 136} 137 138void CollectedHeap::register_nmethod(nmethod* nm) { 139 assert_locked_or_safepoint(CodeCache_lock); 140} 141 142void CollectedHeap::unregister_nmethod(nmethod* nm) { 143 assert_locked_or_safepoint(CodeCache_lock); 144} 145 146void CollectedHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) { 147 const GCHeapSummary& heap_summary = create_heap_summary(); 148 gc_tracer->report_gc_heap_summary(when, heap_summary); 149 150 const MetaspaceSummary& metaspace_summary = create_metaspace_summary(); 151 gc_tracer->report_metaspace_summary(when, metaspace_summary); 152} 153 154void CollectedHeap::trace_heap_before_gc(const GCTracer* gc_tracer) { 155 trace_heap(GCWhen::BeforeGC, gc_tracer); 156} 157 158void CollectedHeap::trace_heap_after_gc(const GCTracer* gc_tracer) { 159 trace_heap(GCWhen::AfterGC, gc_tracer); 160} 161 162// WhiteBox API support for concurrent collectors. These are the 163// default implementations, for collectors which don't support this 164// feature. 165bool CollectedHeap::supports_concurrent_phase_control() const { 166 return false; 167} 168 169const char* const* CollectedHeap::concurrent_phases() const { 170 static const char* const result[] = { NULL }; 171 return result; 172} 173 174bool CollectedHeap::request_concurrent_phase(const char* phase) { 175 return false; 176} 177 178// Memory state functions. 179 180 181CollectedHeap::CollectedHeap() : 182 _barrier_set(NULL), 183 _is_gc_active(false), 184 _total_collections(0), 185 _total_full_collections(0), 186 _gc_cause(GCCause::_no_gc), 187 _gc_lastcause(GCCause::_no_gc), 188 _defer_initial_card_mark(false) // strengthened by subclass in pre_initialize() below. 189{ 190 const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT)); 191 const size_t elements_per_word = HeapWordSize / sizeof(jint); 192 _filler_array_max_size = align_object_size(filler_array_hdr_size() + 193 max_len / elements_per_word); 194 195 NOT_PRODUCT(_promotion_failure_alot_count = 0;) 196 NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;) 197 198 if (UsePerfData) { 199 EXCEPTION_MARK; 200 201 // create the gc cause jvmstat counters 202 _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause", 203 80, GCCause::to_string(_gc_cause), CHECK); 204 205 _perf_gc_lastcause = 206 PerfDataManager::create_string_variable(SUN_GC, "lastCause", 207 80, GCCause::to_string(_gc_lastcause), CHECK); 208 } 209 210 // Create the ring log 211 if (LogEvents) { 212 _gc_heap_log = new GCHeapLog(); 213 } else { 214 _gc_heap_log = NULL; 215 } 216} 217 218// This interface assumes that it's being called by the 219// vm thread. It collects the heap assuming that the 220// heap lock is already held and that we are executing in 221// the context of the vm thread. 222void CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) { 223 assert(Thread::current()->is_VM_thread(), "Precondition#1"); 224 assert(Heap_lock->is_locked(), "Precondition#2"); 225 GCCauseSetter gcs(this, cause); 226 switch (cause) { 227 case GCCause::_heap_inspection: 228 case GCCause::_heap_dump: 229 case GCCause::_metadata_GC_threshold : { 230 HandleMark hm; 231 do_full_collection(false); // don't clear all soft refs 232 break; 233 } 234 case GCCause::_metadata_GC_clear_soft_refs: { 235 HandleMark hm; 236 do_full_collection(true); // do clear all soft refs 237 break; 238 } 239 default: 240 ShouldNotReachHere(); // Unexpected use of this function 241 } 242} 243 244void CollectedHeap::set_barrier_set(BarrierSet* barrier_set) { 245 _barrier_set = barrier_set; 246 oopDesc::set_bs(_barrier_set); 247} 248 249void CollectedHeap::pre_initialize() { 250 // Used for ReduceInitialCardMarks (when COMPILER2 is used); 251 // otherwise remains unused. 252#if defined(COMPILER2) || INCLUDE_JVMCI 253 _defer_initial_card_mark = is_server_compilation_mode_vm() && ReduceInitialCardMarks && can_elide_tlab_store_barriers() 254 && (DeferInitialCardMark || card_mark_must_follow_store()); 255#else 256 assert(_defer_initial_card_mark == false, "Who would set it?"); 257#endif 258} 259 260#ifndef PRODUCT 261void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) { 262 if (CheckMemoryInitialization && ZapUnusedHeapArea) { 263 for (size_t slot = 0; slot < size; slot += 1) { 264 assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal), 265 "Found badHeapWordValue in post-allocation check"); 266 } 267 } 268} 269 270void CollectedHeap::check_for_non_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 non badHeapWordValue in pre-allocation check"); 275 } 276 } 277} 278#endif // PRODUCT 279 280#ifdef ASSERT 281void CollectedHeap::check_for_valid_allocation_state() { 282 Thread *thread = Thread::current(); 283 // How to choose between a pending exception and a potential 284 // OutOfMemoryError? Don't allow pending exceptions. 285 // This is a VM policy failure, so how do we exhaustively test it? 286 assert(!thread->has_pending_exception(), 287 "shouldn't be allocating with pending exception"); 288 if (StrictSafepointChecks) { 289 assert(thread->allow_allocation(), 290 "Allocation done by thread for which allocation is blocked " 291 "by No_Allocation_Verifier!"); 292 // Allocation of an oop can always invoke a safepoint, 293 // hence, the true argument 294 thread->check_for_valid_safepoint_state(true); 295 } 296} 297#endif 298 299HeapWord* CollectedHeap::allocate_from_tlab_slow(Klass* klass, Thread* thread, size_t size) { 300 301 // Retain tlab and allocate object in shared space if 302 // the amount free in the tlab is too large to discard. 303 if (thread->tlab().free() > thread->tlab().refill_waste_limit()) { 304 thread->tlab().record_slow_allocation(size); 305 return NULL; 306 } 307 308 // Discard tlab and allocate a new one. 309 // To minimize fragmentation, the last TLAB may be smaller than the rest. 310 size_t new_tlab_size = thread->tlab().compute_size(size); 311 312 thread->tlab().clear_before_allocation(); 313 314 if (new_tlab_size == 0) { 315 return NULL; 316 } 317 318 // Allocate a new TLAB... 319 HeapWord* obj = Universe::heap()->allocate_new_tlab(new_tlab_size); 320 if (obj == NULL) { 321 return NULL; 322 } 323 324 AllocTracer::send_allocation_in_new_tlab_event(klass, new_tlab_size * HeapWordSize, size * HeapWordSize); 325 326 if (ZeroTLAB) { 327 // ..and clear it. 328 Copy::zero_to_words(obj, new_tlab_size); 329 } else { 330 // ...and zap just allocated object. 331#ifdef ASSERT 332 // Skip mangling the space corresponding to the object header to 333 // ensure that the returned space is not considered parsable by 334 // any concurrent GC thread. 335 size_t hdr_size = oopDesc::header_size(); 336 Copy::fill_to_words(obj + hdr_size, new_tlab_size - hdr_size, badHeapWordVal); 337#endif // ASSERT 338 } 339 thread->tlab().fill(obj, obj + size, new_tlab_size); 340 return obj; 341} 342 343void CollectedHeap::flush_deferred_store_barrier(JavaThread* thread) { 344 MemRegion deferred = thread->deferred_card_mark(); 345 if (!deferred.is_empty()) { 346 assert(_defer_initial_card_mark, "Otherwise should be empty"); 347 { 348 // Verify that the storage points to a parsable object in heap 349 DEBUG_ONLY(oop old_obj = oop(deferred.start());) 350 assert(is_in(old_obj), "Not in allocated heap"); 351 assert(!can_elide_initializing_store_barrier(old_obj), 352 "Else should have been filtered in new_store_pre_barrier()"); 353 assert(old_obj->is_oop(true), "Not an oop"); 354 assert(deferred.word_size() == (size_t)(old_obj->size()), 355 "Mismatch: multiple objects?"); 356 } 357 BarrierSet* bs = barrier_set(); 358 assert(bs->has_write_region_opt(), "No write_region() on BarrierSet"); 359 bs->write_region(deferred); 360 // "Clear" the deferred_card_mark field 361 thread->set_deferred_card_mark(MemRegion()); 362 } 363 assert(thread->deferred_card_mark().is_empty(), "invariant"); 364} 365 366size_t CollectedHeap::max_tlab_size() const { 367 // TLABs can't be bigger than we can fill with a int[Integer.MAX_VALUE]. 368 // This restriction could be removed by enabling filling with multiple arrays. 369 // If we compute that the reasonable way as 370 // header_size + ((sizeof(jint) * max_jint) / HeapWordSize) 371 // we'll overflow on the multiply, so we do the divide first. 372 // We actually lose a little by dividing first, 373 // but that just makes the TLAB somewhat smaller than the biggest array, 374 // which is fine, since we'll be able to fill that. 375 size_t max_int_size = typeArrayOopDesc::header_size(T_INT) + 376 sizeof(jint) * 377 ((juint) max_jint / (size_t) HeapWordSize); 378 return align_down(max_int_size, MinObjAlignment); 379} 380 381// Helper for ReduceInitialCardMarks. For performance, 382// compiled code may elide card-marks for initializing stores 383// to a newly allocated object along the fast-path. We 384// compensate for such elided card-marks as follows: 385// (a) Generational, non-concurrent collectors, such as 386// GenCollectedHeap(ParNew,DefNew,Tenured) and 387// ParallelScavengeHeap(ParallelGC, ParallelOldGC) 388// need the card-mark if and only if the region is 389// in the old gen, and do not care if the card-mark 390// succeeds or precedes the initializing stores themselves, 391// so long as the card-mark is completed before the next 392// scavenge. For all these cases, we can do a card mark 393// at the point at which we do a slow path allocation 394// in the old gen, i.e. in this call. 395// (b) GenCollectedHeap(ConcurrentMarkSweepGeneration) requires 396// in addition that the card-mark for an old gen allocated 397// object strictly follow any associated initializing stores. 398// In these cases, the memRegion remembered below is 399// used to card-mark the entire region either just before the next 400// slow-path allocation by this thread or just before the next scavenge or 401// CMS-associated safepoint, whichever of these events happens first. 402// (The implicit assumption is that the object has been fully 403// initialized by this point, a fact that we assert when doing the 404// card-mark.) 405// (c) G1CollectedHeap(G1) uses two kinds of write barriers. When a 406// G1 concurrent marking is in progress an SATB (pre-write-)barrier 407// is used to remember the pre-value of any store. Initializing 408// stores will not need this barrier, so we need not worry about 409// compensating for the missing pre-barrier here. Turning now 410// to the post-barrier, we note that G1 needs a RS update barrier 411// which simply enqueues a (sequence of) dirty cards which may 412// optionally be refined by the concurrent update threads. Note 413// that this barrier need only be applied to a non-young write, 414// but, like in CMS, because of the presence of concurrent refinement 415// (much like CMS' precleaning), must strictly follow the oop-store. 416// Thus, using the same protocol for maintaining the intended 417// invariants turns out, serendepitously, to be the same for both 418// G1 and CMS. 419// 420// For any future collector, this code should be reexamined with 421// that specific collector in mind, and the documentation above suitably 422// extended and updated. 423oop CollectedHeap::new_store_pre_barrier(JavaThread* thread, oop new_obj) { 424 // If a previous card-mark was deferred, flush it now. 425 flush_deferred_store_barrier(thread); 426 if (can_elide_initializing_store_barrier(new_obj) || 427 new_obj->is_typeArray()) { 428 // Arrays of non-references don't need a pre-barrier. 429 // The deferred_card_mark region should be empty 430 // following the flush above. 431 assert(thread->deferred_card_mark().is_empty(), "Error"); 432 } else { 433 MemRegion mr((HeapWord*)new_obj, new_obj->size()); 434 assert(!mr.is_empty(), "Error"); 435 if (_defer_initial_card_mark) { 436 // Defer the card mark 437 thread->set_deferred_card_mark(mr); 438 } else { 439 // Do the card mark 440 BarrierSet* bs = barrier_set(); 441 assert(bs->has_write_region_opt(), "No write_region() on BarrierSet"); 442 bs->write_region(mr); 443 } 444 } 445 return new_obj; 446} 447 448size_t CollectedHeap::filler_array_hdr_size() { 449 return align_object_offset(arrayOopDesc::header_size(T_INT)); // align to Long 450} 451 452size_t CollectedHeap::filler_array_min_size() { 453 return align_object_size(filler_array_hdr_size()); // align to MinObjAlignment 454} 455 456#ifdef ASSERT 457void CollectedHeap::fill_args_check(HeapWord* start, size_t words) 458{ 459 assert(words >= min_fill_size(), "too small to fill"); 460 assert(words % MinObjAlignment == 0, "unaligned size"); 461 assert(Universe::heap()->is_in_reserved(start), "not in heap"); 462 assert(Universe::heap()->is_in_reserved(start + words - 1), "not in heap"); 463} 464 465void CollectedHeap::zap_filler_array(HeapWord* start, size_t words, bool zap) 466{ 467 if (ZapFillerObjects && zap) { 468 Copy::fill_to_words(start + filler_array_hdr_size(), 469 words - filler_array_hdr_size(), 0XDEAFBABE); 470 } 471} 472#endif // ASSERT 473 474void 475CollectedHeap::fill_with_array(HeapWord* start, size_t words, bool zap) 476{ 477 assert(words >= filler_array_min_size(), "too small for an array"); 478 assert(words <= filler_array_max_size(), "too big for a single object"); 479 480 const size_t payload_size = words - filler_array_hdr_size(); 481 const size_t len = payload_size * HeapWordSize / sizeof(jint); 482 assert((int)len >= 0, "size too large " SIZE_FORMAT " becomes %d", words, (int)len); 483 484 // Set the length first for concurrent GC. 485 ((arrayOop)start)->set_length((int)len); 486 post_allocation_setup_common(Universe::intArrayKlassObj(), start); 487 DEBUG_ONLY(zap_filler_array(start, words, zap);) 488} 489 490void 491CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words, bool zap) 492{ 493 assert(words <= filler_array_max_size(), "too big for a single object"); 494 495 if (words >= filler_array_min_size()) { 496 fill_with_array(start, words, zap); 497 } else if (words > 0) { 498 assert(words == min_fill_size(), "unaligned size"); 499 post_allocation_setup_common(SystemDictionary::Object_klass(), start); 500 } 501} 502 503void CollectedHeap::fill_with_object(HeapWord* start, size_t words, bool zap) 504{ 505 DEBUG_ONLY(fill_args_check(start, words);) 506 HandleMark hm; // Free handles before leaving. 507 fill_with_object_impl(start, words, zap); 508} 509 510void CollectedHeap::fill_with_objects(HeapWord* start, size_t words, bool zap) 511{ 512 DEBUG_ONLY(fill_args_check(start, words);) 513 HandleMark hm; // Free handles before leaving. 514 515 // Multiple objects may be required depending on the filler array maximum size. Fill 516 // the range up to that with objects that are filler_array_max_size sized. The 517 // remainder is filled with a single object. 518 const size_t min = min_fill_size(); 519 const size_t max = filler_array_max_size(); 520 while (words > max) { 521 const size_t cur = (words - max) >= min ? max : max - min; 522 fill_with_array(start, cur, zap); 523 start += cur; 524 words -= cur; 525 } 526 527 fill_with_object_impl(start, words, zap); 528} 529 530HeapWord* CollectedHeap::allocate_new_tlab(size_t size) { 531 guarantee(false, "thread-local allocation buffers not supported"); 532 return NULL; 533} 534 535void CollectedHeap::ensure_parsability(bool retire_tlabs) { 536 // The second disjunct in the assertion below makes a concession 537 // for the start-up verification done while the VM is being 538 // created. Callers be careful that you know that mutators 539 // aren't going to interfere -- for instance, this is permissible 540 // if we are still single-threaded and have either not yet 541 // started allocating (nothing much to verify) or we have 542 // started allocating but are now a full-fledged JavaThread 543 // (and have thus made our TLAB's) available for filling. 544 assert(SafepointSynchronize::is_at_safepoint() || 545 !is_init_completed(), 546 "Should only be called at a safepoint or at start-up" 547 " otherwise concurrent mutator activity may make heap " 548 " unparsable again"); 549 const bool use_tlab = UseTLAB; 550 const bool deferred = _defer_initial_card_mark; 551 // The main thread starts allocating via a TLAB even before it 552 // has added itself to the threads list at vm boot-up. 553 assert(!use_tlab || Threads::first() != NULL, 554 "Attempt to fill tlabs before main thread has been added" 555 " to threads list is doomed to failure!"); 556 for (JavaThread *thread = Threads::first(); thread; thread = thread->next()) { 557 if (use_tlab) thread->tlab().make_parsable(retire_tlabs); 558#if defined(COMPILER2) || INCLUDE_JVMCI 559 // The deferred store barriers must all have been flushed to the 560 // card-table (or other remembered set structure) before GC starts 561 // processing the card-table (or other remembered set). 562 if (deferred) flush_deferred_store_barrier(thread); 563#else 564 assert(!deferred, "Should be false"); 565 assert(thread->deferred_card_mark().is_empty(), "Should be empty"); 566#endif 567 } 568} 569 570void CollectedHeap::accumulate_statistics_all_tlabs() { 571 if (UseTLAB) { 572 assert(SafepointSynchronize::is_at_safepoint() || 573 !is_init_completed(), 574 "should only accumulate statistics on tlabs at safepoint"); 575 576 ThreadLocalAllocBuffer::accumulate_statistics_before_gc(); 577 } 578} 579 580void CollectedHeap::resize_all_tlabs() { 581 if (UseTLAB) { 582 assert(SafepointSynchronize::is_at_safepoint() || 583 !is_init_completed(), 584 "should only resize tlabs at safepoint"); 585 586 ThreadLocalAllocBuffer::resize_all_tlabs(); 587 } 588} 589 590void CollectedHeap::full_gc_dump(GCTimer* timer, bool before) { 591 assert(timer != NULL, "timer is null"); 592 if ((HeapDumpBeforeFullGC && before) || (HeapDumpAfterFullGC && !before)) { 593 GCTraceTime(Info, gc) tm(before ? "Heap Dump (before full gc)" : "Heap Dump (after full gc)", timer); 594 HeapDumper::dump_heap(); 595 } 596 597 Log(gc, classhisto) log; 598 if (log.is_trace()) { 599 GCTraceTime(Trace, gc, classhisto) tm(before ? "Class Histogram (before full gc)" : "Class Histogram (after full gc)", timer); 600 ResourceMark rm; 601 VM_GC_HeapInspection inspector(log.trace_stream(), false /* ! full gc */); 602 inspector.doit(); 603 } 604} 605 606void CollectedHeap::pre_full_gc_dump(GCTimer* timer) { 607 full_gc_dump(timer, true); 608} 609 610void CollectedHeap::post_full_gc_dump(GCTimer* timer) { 611 full_gc_dump(timer, false); 612} 613 614void CollectedHeap::initialize_reserved_region(HeapWord *start, HeapWord *end) { 615 // It is important to do this in a way such that concurrent readers can't 616 // temporarily think something is in the heap. (Seen this happen in asserts.) 617 _reserved.set_word_size(0); 618 _reserved.set_start(start); 619 _reserved.set_end(end); 620} 621