1 /* 2 * Copyright (c) 2001, 2015, 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.hpp" 34 #include "gc/shared/gcWhen.hpp" 35 #include "gc/shared/vmGCOperations.hpp" 36 #include "memory/metaspace.hpp" 37 #include "oops/instanceMirrorKlass.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "runtime/init.hpp" 40 #include "runtime/thread.inline.hpp" 41 #include "services/heapDumper.hpp" 42 43 44 #ifdef ASSERT 45 int CollectedHeap::_fire_out_of_memory_count = 0; 46 #endif 47 48 size_t CollectedHeap::_filler_array_max_size = 0; 49 50 template <> 51 void EventLogBase<GCMessage>::print(outputStream* st, GCMessage& m) { 52 st->print_cr("GC heap %s", m.is_before ? "before" : "after"); 53 st->print_raw(m); 54 } 55 56 void GCHeapLog::log_heap(bool before) { 57 if (!should_log()) { 58 return; 59 } 60 61 double timestamp = fetch_timestamp(); 62 MutexLockerEx ml(&_mutex, Mutex::_no_safepoint_check_flag); 63 int index = compute_log_index(); 64 _records[index].thread = NULL; // Its the GC thread so it's not that interesting. 65 _records[index].timestamp = timestamp; 66 _records[index].data.is_before = before; 67 stringStream st(_records[index].data.buffer(), _records[index].data.size()); 68 if (before) { 69 Universe::print_heap_before_gc(&st, true); 70 } else { 71 Universe::print_heap_after_gc(&st, true); 72 } 73 } 74 75 VirtualSpaceSummary CollectedHeap::create_heap_space_summary() { 76 size_t capacity_in_words = capacity() / HeapWordSize; 77 78 return VirtualSpaceSummary( 79 reserved_region().start(), reserved_region().start() + capacity_in_words, reserved_region().end()); 80 } 81 82 GCHeapSummary CollectedHeap::create_heap_summary() { 83 VirtualSpaceSummary heap_space = create_heap_space_summary(); 84 return GCHeapSummary(heap_space, used()); 85 } 86 87 MetaspaceSummary CollectedHeap::create_metaspace_summary() { 88 const MetaspaceSizes meta_space( 89 MetaspaceAux::committed_bytes(), 90 MetaspaceAux::used_bytes(), 91 MetaspaceAux::reserved_bytes()); 92 const MetaspaceSizes data_space( 93 MetaspaceAux::committed_bytes(Metaspace::NonClassType), 94 MetaspaceAux::used_bytes(Metaspace::NonClassType), 95 MetaspaceAux::reserved_bytes(Metaspace::NonClassType)); 96 const MetaspaceSizes class_space( 97 MetaspaceAux::committed_bytes(Metaspace::ClassType), 98 MetaspaceAux::used_bytes(Metaspace::ClassType), 99 MetaspaceAux::reserved_bytes(Metaspace::ClassType)); 100 101 const MetaspaceChunkFreeListSummary& ms_chunk_free_list_summary = 102 MetaspaceAux::chunk_free_list_summary(Metaspace::NonClassType); 103 const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary = 104 MetaspaceAux::chunk_free_list_summary(Metaspace::ClassType); 105 106 return MetaspaceSummary(MetaspaceGC::capacity_until_GC(), meta_space, data_space, class_space, 107 ms_chunk_free_list_summary, class_chunk_free_list_summary); 108 } 109 110 void CollectedHeap::print_heap_before_gc() { 111 if (PrintHeapAtGC) { 112 Universe::print_heap_before_gc(); 113 } 114 if (_gc_heap_log != NULL) { 115 _gc_heap_log->log_heap_before(); 116 } 117 } 118 119 void CollectedHeap::print_heap_after_gc() { 120 if (PrintHeapAtGC) { 121 Universe::print_heap_after_gc(); 122 } 123 if (_gc_heap_log != NULL) { 124 _gc_heap_log->log_heap_after(); 125 } 126 } 127 128 void CollectedHeap::print_on_error(outputStream* st) const { 129 st->print_cr("Heap:"); 130 print_extended_on(st); 131 st->cr(); 132 133 _barrier_set->print_on(st); 134 } 135 136 void CollectedHeap::register_nmethod(nmethod* nm) { 137 assert_locked_or_safepoint(CodeCache_lock); 138 } 139 140 void CollectedHeap::unregister_nmethod(nmethod* nm) { 141 assert_locked_or_safepoint(CodeCache_lock); 142 } 143 144 void CollectedHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) { 145 const GCHeapSummary& heap_summary = create_heap_summary(); 146 gc_tracer->report_gc_heap_summary(when, heap_summary); 147 148 const MetaspaceSummary& metaspace_summary = create_metaspace_summary(); 149 gc_tracer->report_metaspace_summary(when, metaspace_summary); 150 } 151 152 void CollectedHeap::trace_heap_before_gc(const GCTracer* gc_tracer) { 153 trace_heap(GCWhen::BeforeGC, gc_tracer); 154 } 155 156 void CollectedHeap::trace_heap_after_gc(const GCTracer* gc_tracer) { 157 trace_heap(GCWhen::AfterGC, gc_tracer); 158 } 159 160 // Memory state functions. 161 162 163 CollectedHeap::CollectedHeap() : 164 _barrier_set(NULL), 165 _is_gc_active(false), 166 _total_collections(0), 167 _total_full_collections(0), 168 _gc_cause(GCCause::_no_gc), 169 _gc_lastcause(GCCause::_no_gc), 170 _defer_initial_card_mark(false) // strengthened by subclass in pre_initialize() below. 171 { 172 const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT)); 173 const size_t elements_per_word = HeapWordSize / sizeof(jint); 174 _filler_array_max_size = align_object_size(filler_array_hdr_size() + 175 max_len / elements_per_word); 176 177 NOT_PRODUCT(_promotion_failure_alot_count = 0;) 178 NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;) 179 180 if (UsePerfData) { 181 EXCEPTION_MARK; 182 183 // create the gc cause jvmstat counters 184 _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause", 185 80, GCCause::to_string(_gc_cause), CHECK); 186 187 _perf_gc_lastcause = 188 PerfDataManager::create_string_variable(SUN_GC, "lastCause", 189 80, GCCause::to_string(_gc_lastcause), CHECK); 190 } 191 192 // Create the ring log 193 if (LogEvents) { 194 _gc_heap_log = new GCHeapLog(); 195 } else { 196 _gc_heap_log = NULL; 197 } 198 } 199 200 // This interface assumes that it's being called by the 201 // vm thread. It collects the heap assuming that the 202 // heap lock is already held and that we are executing in 203 // the context of the vm thread. 204 void CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) { 205 assert(Thread::current()->is_VM_thread(), "Precondition#1"); 206 assert(Heap_lock->is_locked(), "Precondition#2"); 207 GCCauseSetter gcs(this, cause); 208 switch (cause) { 209 case GCCause::_heap_inspection: 210 case GCCause::_heap_dump: 211 case GCCause::_metadata_GC_threshold : { 212 HandleMark hm; 213 do_full_collection(false); // don't clear all soft refs 214 break; 215 } 216 case GCCause::_last_ditch_collection: { 217 HandleMark hm; 218 do_full_collection(true); // do clear all soft refs 219 break; 220 } 221 default: 222 ShouldNotReachHere(); // Unexpected use of this function 223 } 224 } 225 226 void CollectedHeap::set_barrier_set(BarrierSet* barrier_set) { 227 _barrier_set = barrier_set; 228 oopDesc::set_bs(_barrier_set); 229 } 230 231 void CollectedHeap::pre_initialize() { 232 // Used for ReduceInitialCardMarks (when COMPILER2 is used); 233 // otherwise remains unused. 234 #ifdef COMPILER2 235 _defer_initial_card_mark = ReduceInitialCardMarks && can_elide_tlab_store_barriers() 236 && (DeferInitialCardMark || card_mark_must_follow_store()); 237 #else 238 assert(_defer_initial_card_mark == false, "Who would set it?"); 239 #endif 240 } 241 242 #ifndef PRODUCT 243 void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) { 244 if (CheckMemoryInitialization && ZapUnusedHeapArea) { 245 for (size_t slot = 0; slot < size; slot += 1) { 246 assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal), 247 "Found badHeapWordValue in post-allocation check"); 248 } 249 } 250 } 251 252 void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size) { 253 if (CheckMemoryInitialization && ZapUnusedHeapArea) { 254 for (size_t slot = 0; slot < size; slot += 1) { 255 assert((*(intptr_t*) (addr + slot)) == ((intptr_t) badHeapWordVal), 256 "Found non badHeapWordValue in pre-allocation check"); 257 } 258 } 259 } 260 #endif // PRODUCT 261 262 #ifdef ASSERT 263 void CollectedHeap::check_for_valid_allocation_state() { 264 Thread *thread = Thread::current(); 265 // How to choose between a pending exception and a potential 266 // OutOfMemoryError? Don't allow pending exceptions. 267 // This is a VM policy failure, so how do we exhaustively test it? 268 assert(!thread->has_pending_exception(), 269 "shouldn't be allocating with pending exception"); 270 if (StrictSafepointChecks) { 271 assert(thread->allow_allocation(), 272 "Allocation done by thread for which allocation is blocked " 273 "by No_Allocation_Verifier!"); 274 // Allocation of an oop can always invoke a safepoint, 275 // hence, the true argument 276 thread->check_for_valid_safepoint_state(true); 277 } 278 } 279 #endif 280 281 HeapWord* CollectedHeap::allocate_from_tlab_slow(KlassHandle klass, Thread* thread, size_t size) { 282 283 // Retain tlab and allocate object in shared space if 284 // the amount free in the tlab is too large to discard. 285 if (thread->tlab().free() > thread->tlab().refill_waste_limit()) { 286 thread->tlab().record_slow_allocation(size); 287 return NULL; 288 } 289 290 // Discard tlab and allocate a new one. 291 // To minimize fragmentation, the last TLAB may be smaller than the rest. 292 size_t new_tlab_size = thread->tlab().compute_size(size); 293 294 thread->tlab().clear_before_allocation(); 295 296 if (new_tlab_size == 0) { 297 return NULL; 298 } 299 300 // Allocate a new TLAB... 301 HeapWord* obj = Universe::heap()->allocate_new_tlab(new_tlab_size); 302 if (obj == NULL) { 303 return NULL; 304 } 305 306 AllocTracer::send_allocation_in_new_tlab_event(klass, new_tlab_size * HeapWordSize, size * HeapWordSize); 307 308 if (ZeroTLAB) { 309 // ..and clear it. 310 Copy::zero_to_words(obj, new_tlab_size); 311 } else { 312 // ...and zap just allocated object. 313 #ifdef ASSERT 314 // Skip mangling the space corresponding to the object header to 315 // ensure that the returned space is not considered parsable by 316 // any concurrent GC thread. 317 size_t hdr_size = oopDesc::header_size(); 318 Copy::fill_to_words(obj + hdr_size, new_tlab_size - hdr_size, badHeapWordVal); 319 #endif // ASSERT 320 } 321 thread->tlab().fill(obj, obj + size, new_tlab_size); 322 return Universe::heap()->tlab_post_allocation_setup(obj); 323 } 324 325 void CollectedHeap::flush_deferred_store_barrier(JavaThread* thread) { 326 MemRegion deferred = thread->deferred_card_mark(); 327 if (!deferred.is_empty()) { 328 assert(_defer_initial_card_mark, "Otherwise should be empty"); 329 { 330 // Verify that the storage points to a parsable object in heap 331 DEBUG_ONLY(oop old_obj = oop(deferred.start());) 332 assert(is_in(old_obj), "Not in allocated heap"); 333 assert(!can_elide_initializing_store_barrier(old_obj), 334 "Else should have been filtered in new_store_pre_barrier()"); 335 assert(old_obj->is_oop(true), "Not an oop"); 336 assert(deferred.word_size() == (size_t)(old_obj->size()), 337 "Mismatch: multiple objects?"); 338 } 339 BarrierSet* bs = barrier_set(); 340 assert(bs->has_write_region_opt(), "No write_region() on BarrierSet"); 341 bs->write_region(deferred); 342 // "Clear" the deferred_card_mark field 343 thread->set_deferred_card_mark(MemRegion()); 344 } 345 assert(thread->deferred_card_mark().is_empty(), "invariant"); 346 } 347 348 size_t CollectedHeap::max_tlab_size() const { 349 // TLABs can't be bigger than we can fill with a int[Integer.MAX_VALUE]. 350 // This restriction could be removed by enabling filling with multiple arrays. 351 // If we compute that the reasonable way as 352 // header_size + ((sizeof(jint) * max_jint) / HeapWordSize) 353 // we'll overflow on the multiply, so we do the divide first. 354 // We actually lose a little by dividing first, 355 // but that just makes the TLAB somewhat smaller than the biggest array, 356 // which is fine, since we'll be able to fill that. 357 size_t max_int_size = typeArrayOopDesc::header_size(T_INT) + 358 sizeof(jint) * 359 ((juint) max_jint / (size_t) HeapWordSize); 360 return align_size_down(max_int_size, MinObjAlignment); 361 } 362 363 // Helper for ReduceInitialCardMarks. For performance, 364 // compiled code may elide card-marks for initializing stores 365 // to a newly allocated object along the fast-path. We 366 // compensate for such elided card-marks as follows: 367 // (a) Generational, non-concurrent collectors, such as 368 // GenCollectedHeap(ParNew,DefNew,Tenured) and 369 // ParallelScavengeHeap(ParallelGC, ParallelOldGC) 370 // need the card-mark if and only if the region is 371 // in the old gen, and do not care if the card-mark 372 // succeeds or precedes the initializing stores themselves, 373 // so long as the card-mark is completed before the next 374 // scavenge. For all these cases, we can do a card mark 375 // at the point at which we do a slow path allocation 376 // in the old gen, i.e. in this call. 377 // (b) GenCollectedHeap(ConcurrentMarkSweepGeneration) requires 378 // in addition that the card-mark for an old gen allocated 379 // object strictly follow any associated initializing stores. 380 // In these cases, the memRegion remembered below is 381 // used to card-mark the entire region either just before the next 382 // slow-path allocation by this thread or just before the next scavenge or 383 // CMS-associated safepoint, whichever of these events happens first. 384 // (The implicit assumption is that the object has been fully 385 // initialized by this point, a fact that we assert when doing the 386 // card-mark.) 387 // (c) G1CollectedHeap(G1) uses two kinds of write barriers. When a 388 // G1 concurrent marking is in progress an SATB (pre-write-)barrier is 389 // is used to remember the pre-value of any store. Initializing 390 // stores will not need this barrier, so we need not worry about 391 // compensating for the missing pre-barrier here. Turning now 392 // to the post-barrier, we note that G1 needs a RS update barrier 393 // which simply enqueues a (sequence of) dirty cards which may 394 // optionally be refined by the concurrent update threads. Note 395 // that this barrier need only be applied to a non-young write, 396 // but, like in CMS, because of the presence of concurrent refinement 397 // (much like CMS' precleaning), must strictly follow the oop-store. 398 // Thus, using the same protocol for maintaining the intended 399 // invariants turns out, serendepitously, to be the same for both 400 // G1 and CMS. 401 // 402 // For any future collector, this code should be reexamined with 403 // that specific collector in mind, and the documentation above suitably 404 // extended and updated. 405 oop CollectedHeap::new_store_pre_barrier(JavaThread* thread, oop new_obj) { 406 // If a previous card-mark was deferred, flush it now. 407 flush_deferred_store_barrier(thread); 408 if (can_elide_initializing_store_barrier(new_obj)) { 409 // The deferred_card_mark region should be empty 410 // following the flush above. 411 assert(thread->deferred_card_mark().is_empty(), "Error"); 412 } else { 413 MemRegion mr((HeapWord*)new_obj, new_obj->size()); 414 assert(!mr.is_empty(), "Error"); 415 if (_defer_initial_card_mark) { 416 // Defer the card mark 417 thread->set_deferred_card_mark(mr); 418 } else { 419 // Do the card mark 420 BarrierSet* bs = barrier_set(); 421 assert(bs->has_write_region_opt(), "No write_region() on BarrierSet"); 422 bs->write_region(mr); 423 } 424 } 425 return new_obj; 426 } 427 428 size_t CollectedHeap::filler_array_hdr_size() { 429 return size_t(align_object_offset(arrayOopDesc::header_size(T_INT))); // align to Long 430 } 431 432 size_t CollectedHeap::filler_array_min_size() { 433 return align_object_size(filler_array_hdr_size()); // align to MinObjAlignment 434 } 435 436 #ifdef ASSERT 437 void CollectedHeap::fill_args_check(HeapWord* start, size_t words) 438 { 439 assert(words >= min_fill_size(), "too small to fill"); 440 assert(words % MinObjAlignment == 0, "unaligned size"); 441 assert(Universe::heap()->is_in_reserved(start), "not in heap"); 442 assert(Universe::heap()->is_in_reserved(start + words - 1), "not in heap"); 443 } 444 445 void CollectedHeap::zap_filler_array(HeapWord* start, size_t words, bool zap) 446 { 447 if (ZapFillerObjects && zap) { 448 Copy::fill_to_words(start + filler_array_hdr_size(), 449 words - filler_array_hdr_size(), 0XDEAFBABE); 450 } 451 } 452 #endif // ASSERT 453 454 void 455 CollectedHeap::fill_with_array(HeapWord* start, size_t words, bool zap) 456 { 457 assert(words >= filler_array_min_size(), "too small for an array"); 458 assert(words <= filler_array_max_size(), "too big for a single object"); 459 460 const size_t payload_size = words - filler_array_hdr_size(); 461 const size_t len = payload_size * HeapWordSize / sizeof(jint); 462 assert((int)len >= 0, err_msg("size too large " SIZE_FORMAT " becomes %d", words, (int)len)); 463 464 // Set the length first for concurrent GC. 465 ((arrayOop)start)->set_length((int)len); 466 post_allocation_setup_common(Universe::intArrayKlassObj(), start); 467 DEBUG_ONLY(zap_filler_array(start, words, zap);) 468 } 469 470 void 471 CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words, bool zap) 472 { 473 assert(words <= filler_array_max_size(), "too big for a single object"); 474 475 if (words >= filler_array_min_size()) { 476 fill_with_array(start, words, zap); 477 } else if (words > 0) { 478 assert(words == min_fill_size(), "unaligned size"); 479 post_allocation_setup_common(SystemDictionary::Object_klass(), start); 480 } 481 } 482 483 void CollectedHeap::fill_with_object(HeapWord* start, size_t words, bool zap) 484 { 485 DEBUG_ONLY(fill_args_check(start, words);) 486 HandleMark hm; // Free handles before leaving. 487 fill_with_object_impl(start, words, zap); 488 } 489 490 void CollectedHeap::fill_with_objects(HeapWord* start, size_t words, bool zap) 491 { 492 DEBUG_ONLY(fill_args_check(start, words);) 493 HandleMark hm; // Free handles before leaving. 494 495 // Multiple objects may be required depending on the filler array maximum size. Fill 496 // the range up to that with objects that are filler_array_max_size sized. The 497 // remainder is filled with a single object. 498 const size_t min = min_fill_size(); 499 const size_t max = filler_array_max_size(); 500 while (words > max) { 501 const size_t cur = (words - max) >= min ? max : max - min; 502 fill_with_array(start, cur, zap); 503 start += cur; 504 words -= cur; 505 } 506 507 fill_with_object_impl(start, words, zap); 508 } 509 510 void CollectedHeap::post_initialize() { 511 collector_policy()->post_heap_initialize(); 512 } 513 514 HeapWord* CollectedHeap::allocate_new_tlab(size_t size) { 515 guarantee(false, "thread-local allocation buffers not supported"); 516 return NULL; 517 } 518 519 void CollectedHeap::ensure_parsability(bool retire_tlabs) { 520 // The second disjunct in the assertion below makes a concession 521 // for the start-up verification done while the VM is being 522 // created. Callers be careful that you know that mutators 523 // aren't going to interfere -- for instance, this is permissible 524 // if we are still single-threaded and have either not yet 525 // started allocating (nothing much to verify) or we have 526 // started allocating but are now a full-fledged JavaThread 527 // (and have thus made our TLAB's) available for filling. 528 assert(SafepointSynchronize::is_at_safepoint() || 529 !is_init_completed(), 530 "Should only be called at a safepoint or at start-up" 531 " otherwise concurrent mutator activity may make heap " 532 " unparsable again"); 533 const bool use_tlab = UseTLAB; 534 const bool deferred = _defer_initial_card_mark; 535 // The main thread starts allocating via a TLAB even before it 536 // has added itself to the threads list at vm boot-up. 537 assert(!use_tlab || Threads::first() != NULL, 538 "Attempt to fill tlabs before main thread has been added" 539 " to threads list is doomed to failure!"); 540 for (JavaThread *thread = Threads::first(); thread; thread = thread->next()) { 541 if (use_tlab) thread->tlab().make_parsable(retire_tlabs); 542 #ifdef COMPILER2 543 // The deferred store barriers must all have been flushed to the 544 // card-table (or other remembered set structure) before GC starts 545 // processing the card-table (or other remembered set). 546 if (deferred) flush_deferred_store_barrier(thread); 547 #else 548 assert(!deferred, "Should be false"); 549 assert(thread->deferred_card_mark().is_empty(), "Should be empty"); 550 #endif 551 } 552 } 553 554 void CollectedHeap::accumulate_statistics_all_tlabs() { 555 if (UseTLAB) { 556 assert(SafepointSynchronize::is_at_safepoint() || 557 !is_init_completed(), 558 "should only accumulate statistics on tlabs at safepoint"); 559 560 ThreadLocalAllocBuffer::accumulate_statistics_before_gc(); 561 } 562 } 563 564 void CollectedHeap::resize_all_tlabs() { 565 if (UseTLAB) { 566 assert(SafepointSynchronize::is_at_safepoint() || 567 !is_init_completed(), 568 "should only resize tlabs at safepoint"); 569 570 ThreadLocalAllocBuffer::resize_all_tlabs(); 571 } 572 } 573 574 void CollectedHeap::pre_full_gc_dump(GCTimer* timer) { 575 if (HeapDumpBeforeFullGC) { 576 GCTraceTime tt("Heap Dump (before full gc): ", PrintGCDetails, false, timer, GCId::create()); 577 // We are doing a full collection and a heap dump before 578 // full collection has been requested. 579 HeapDumper::dump_heap(); 580 } 581 if (PrintClassHistogramBeforeFullGC) { 582 GCTraceTime tt("Class Histogram (before full gc): ", PrintGCDetails, true, timer, GCId::create()); 583 VM_GC_HeapInspection inspector(gclog_or_tty, false /* ! full gc */); 584 inspector.doit(); 585 } 586 } 587 588 void CollectedHeap::post_full_gc_dump(GCTimer* timer) { 589 if (HeapDumpAfterFullGC) { 590 GCTraceTime tt("Heap Dump (after full gc): ", PrintGCDetails, false, timer, GCId::create()); 591 HeapDumper::dump_heap(); 592 } 593 if (PrintClassHistogramAfterFullGC) { 594 GCTraceTime tt("Class Histogram (after full gc): ", PrintGCDetails, true, timer, GCId::create()); 595 VM_GC_HeapInspection inspector(gclog_or_tty, false /* ! full gc */); 596 inspector.doit(); 597 } 598 } 599 600 void CollectedHeap::initialize_reserved_region(HeapWord *start, HeapWord *end) { 601 // It is important to do this in a way such that concurrent readers can't 602 // temporarily think something is in the heap. (Seen this happen in asserts.) 603 _reserved.set_word_size(0); 604 _reserved.set_start(start); 605 _reserved.set_end(end); 606 } 607 608 /////////////// Unit tests /////////////// 609 610 #ifndef PRODUCT 611 void CollectedHeap::test_is_in() { 612 CollectedHeap* heap = Universe::heap(); 613 614 uintptr_t epsilon = (uintptr_t) MinObjAlignment; 615 uintptr_t heap_start = (uintptr_t) heap->_reserved.start(); 616 uintptr_t heap_end = (uintptr_t) heap->_reserved.end(); 617 618 // Test that NULL is not in the heap. 619 assert(!heap->is_in(NULL), "NULL is unexpectedly in the heap"); 620 621 // Test that a pointer to before the heap start is reported as outside the heap. 622 assert(heap_start >= ((uintptr_t)NULL + epsilon), "sanity"); 623 void* before_heap = (void*)(heap_start - epsilon); 624 assert(!heap->is_in(before_heap), 625 err_msg("before_heap: " PTR_FORMAT " is unexpectedly in the heap", p2i(before_heap))); 626 627 // Test that a pointer to after the heap end is reported as outside the heap. 628 assert(heap_end <= ((uintptr_t)-1 - epsilon), "sanity"); 629 void* after_heap = (void*)(heap_end + epsilon); 630 assert(!heap->is_in(after_heap), 631 err_msg("after_heap: " PTR_FORMAT " is unexpectedly in the heap", p2i(after_heap))); 632 } 633 #endif 634 635 HeapWord* CollectedHeap::tlab_post_allocation_setup(HeapWord* obj) { 636 return obj; 637 } 638 639 uint CollectedHeap::oop_extra_words() { 640 // Default implementation doesn't need extra space for oops. 641 return 0; 642 } 643 644 void CollectedHeap::shutdown() { 645 // Default implementation does nothing. 646 } 647 648 void CollectedHeap::accumulate_statistics_all_gclabs() { 649 // Default implementation does nothing. 650 } 651 652 #ifndef CC_INTERP 653 void CollectedHeap::compile_prepare_oop(MacroAssembler* masm, Register obj) { 654 // Default implementation does nothing. 655 } 656 #endif