1 /* 2 * Copyright (c) 2000, 2020, 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 "aot/aotLoader.hpp" 27 #include "classfile/classLoaderDataGraph.hpp" 28 #include "classfile/symbolTable.hpp" 29 #include "classfile/stringTable.hpp" 30 #include "classfile/vmSymbols.hpp" 31 #include "code/codeCache.hpp" 32 #include "code/icBuffer.hpp" 33 #include "gc/serial/defNewGeneration.hpp" 34 #include "gc/shared/adaptiveSizePolicy.hpp" 35 #include "gc/shared/cardTableBarrierSet.hpp" 36 #include "gc/shared/cardTableRS.hpp" 37 #include "gc/shared/collectedHeap.inline.hpp" 38 #include "gc/shared/collectorCounters.hpp" 39 #include "gc/shared/gcId.hpp" 40 #include "gc/shared/gcLocker.hpp" 41 #include "gc/shared/gcPolicyCounters.hpp" 42 #include "gc/shared/gcTrace.hpp" 43 #include "gc/shared/gcTraceTime.inline.hpp" 44 #include "gc/shared/genArguments.hpp" 45 #include "gc/shared/gcVMOperations.hpp" 46 #include "gc/shared/genCollectedHeap.hpp" 47 #include "gc/shared/genOopClosures.inline.hpp" 48 #include "gc/shared/generationSpec.hpp" 49 #include "gc/shared/gcInitLogger.hpp" 50 #include "gc/shared/locationPrinter.inline.hpp" 51 #include "gc/shared/oopStorage.inline.hpp" 52 #include "gc/shared/oopStorageSet.inline.hpp" 53 #include "gc/shared/oopStorageParState.inline.hpp" 54 #include "gc/shared/scavengableNMethods.hpp" 55 #include "gc/shared/space.hpp" 56 #include "gc/shared/strongRootsScope.hpp" 57 #include "gc/shared/weakProcessor.hpp" 58 #include "gc/shared/workgroup.hpp" 59 #include "memory/filemap.hpp" 60 #include "memory/iterator.hpp" 61 #include "memory/metaspaceCounters.hpp" 62 #include "memory/metaspace/metaspaceSizesSnapshot.hpp" 63 #include "memory/resourceArea.hpp" 64 #include "memory/universe.hpp" 65 #include "oops/oop.inline.hpp" 66 #include "runtime/biasedLocking.hpp" 67 #include "runtime/handles.hpp" 68 #include "runtime/handles.inline.hpp" 69 #include "runtime/java.hpp" 70 #include "runtime/vmThread.hpp" 71 #include "services/memoryService.hpp" 72 #include "utilities/autoRestore.hpp" 73 #include "utilities/debug.hpp" 74 #include "utilities/formatBuffer.hpp" 75 #include "utilities/macros.hpp" 76 #include "utilities/stack.inline.hpp" 77 #include "utilities/vmError.hpp" 78 #if INCLUDE_JVMCI 79 #include "jvmci/jvmci.hpp" 80 #endif 81 82 GenCollectedHeap::GenCollectedHeap(Generation::Name young, 83 Generation::Name old, 84 const char* policy_counters_name) : 85 CollectedHeap(), 86 _young_gen(NULL), 87 _old_gen(NULL), 88 _young_gen_spec(new GenerationSpec(young, 89 NewSize, 90 MaxNewSize, 91 GenAlignment)), 92 _old_gen_spec(new GenerationSpec(old, 93 OldSize, 94 MaxOldSize, 95 GenAlignment)), 96 _rem_set(NULL), 97 _soft_ref_gen_policy(), 98 _size_policy(NULL), 99 _gc_policy_counters(new GCPolicyCounters(policy_counters_name, 2, 2)), 100 _incremental_collection_failed(false), 101 _full_collections_completed(0), 102 _process_strong_tasks(new SubTasksDone(GCH_PS_NumElements)), 103 _young_manager(NULL), 104 _old_manager(NULL) { 105 } 106 107 jint GenCollectedHeap::initialize() { 108 // While there are no constraints in the GC code that HeapWordSize 109 // be any particular value, there are multiple other areas in the 110 // system which believe this to be true (e.g. oop->object_size in some 111 // cases incorrectly returns the size in wordSize units rather than 112 // HeapWordSize). 113 guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize"); 114 115 // Allocate space for the heap. 116 117 ReservedHeapSpace heap_rs = allocate(HeapAlignment); 118 119 if (!heap_rs.is_reserved()) { 120 vm_shutdown_during_initialization( 121 "Could not reserve enough space for object heap"); 122 return JNI_ENOMEM; 123 } 124 125 initialize_reserved_region(heap_rs); 126 127 _rem_set = create_rem_set(heap_rs.region()); 128 _rem_set->initialize(); 129 CardTableBarrierSet *bs = new CardTableBarrierSet(_rem_set); 130 bs->initialize(); 131 BarrierSet::set_barrier_set(bs); 132 133 ReservedSpace young_rs = heap_rs.first_part(_young_gen_spec->max_size()); 134 _young_gen = _young_gen_spec->init(young_rs, rem_set()); 135 ReservedSpace old_rs = heap_rs.last_part(_young_gen_spec->max_size()); 136 137 old_rs = old_rs.first_part(_old_gen_spec->max_size()); 138 _old_gen = _old_gen_spec->init(old_rs, rem_set()); 139 140 GCInitLogger::print(); 141 142 return JNI_OK; 143 } 144 145 CardTableRS* GenCollectedHeap::create_rem_set(const MemRegion& reserved_region) { 146 return new CardTableRS(reserved_region, false /* scan_concurrently */); 147 } 148 149 void GenCollectedHeap::initialize_size_policy(size_t init_eden_size, 150 size_t init_promo_size, 151 size_t init_survivor_size) { 152 const double max_gc_pause_sec = ((double) MaxGCPauseMillis) / 1000.0; 153 _size_policy = new AdaptiveSizePolicy(init_eden_size, 154 init_promo_size, 155 init_survivor_size, 156 max_gc_pause_sec, 157 GCTimeRatio); 158 } 159 160 ReservedHeapSpace GenCollectedHeap::allocate(size_t alignment) { 161 // Now figure out the total size. 162 const size_t pageSize = UseLargePages ? os::large_page_size() : os::vm_page_size(); 163 assert(alignment % pageSize == 0, "Must be"); 164 165 // Check for overflow. 166 size_t total_reserved = _young_gen_spec->max_size() + _old_gen_spec->max_size(); 167 if (total_reserved < _young_gen_spec->max_size()) { 168 vm_exit_during_initialization("The size of the object heap + VM data exceeds " 169 "the maximum representable size"); 170 } 171 assert(total_reserved % alignment == 0, 172 "Gen size; total_reserved=" SIZE_FORMAT ", alignment=" 173 SIZE_FORMAT, total_reserved, alignment); 174 175 ReservedHeapSpace heap_rs = Universe::reserve_heap(total_reserved, alignment); 176 177 os::trace_page_sizes("Heap", 178 MinHeapSize, 179 total_reserved, 180 alignment, 181 heap_rs.base(), 182 heap_rs.size()); 183 184 return heap_rs; 185 } 186 187 class GenIsScavengable : public BoolObjectClosure { 188 public: 189 bool do_object_b(oop obj) { 190 return GenCollectedHeap::heap()->is_in_young(obj); 191 } 192 }; 193 194 static GenIsScavengable _is_scavengable; 195 196 void GenCollectedHeap::post_initialize() { 197 CollectedHeap::post_initialize(); 198 ref_processing_init(); 199 200 DefNewGeneration* def_new_gen = (DefNewGeneration*)_young_gen; 201 202 initialize_size_policy(def_new_gen->eden()->capacity(), 203 _old_gen->capacity(), 204 def_new_gen->from()->capacity()); 205 206 MarkSweep::initialize(); 207 208 ScavengableNMethods::initialize(&_is_scavengable); 209 } 210 211 void GenCollectedHeap::ref_processing_init() { 212 _young_gen->ref_processor_init(); 213 _old_gen->ref_processor_init(); 214 } 215 216 PreGenGCValues GenCollectedHeap::get_pre_gc_values() const { 217 const DefNewGeneration* const def_new_gen = (DefNewGeneration*) young_gen(); 218 219 return PreGenGCValues(def_new_gen->used(), 220 def_new_gen->capacity(), 221 def_new_gen->eden()->used(), 222 def_new_gen->eden()->capacity(), 223 def_new_gen->from()->used(), 224 def_new_gen->from()->capacity(), 225 old_gen()->used(), 226 old_gen()->capacity()); 227 } 228 229 GenerationSpec* GenCollectedHeap::young_gen_spec() const { 230 return _young_gen_spec; 231 } 232 233 GenerationSpec* GenCollectedHeap::old_gen_spec() const { 234 return _old_gen_spec; 235 } 236 237 size_t GenCollectedHeap::capacity() const { 238 return _young_gen->capacity() + _old_gen->capacity(); 239 } 240 241 size_t GenCollectedHeap::used() const { 242 return _young_gen->used() + _old_gen->used(); 243 } 244 245 void GenCollectedHeap::save_used_regions() { 246 _old_gen->save_used_region(); 247 _young_gen->save_used_region(); 248 } 249 250 size_t GenCollectedHeap::max_capacity() const { 251 return _young_gen->max_capacity() + _old_gen->max_capacity(); 252 } 253 254 // Update the _full_collections_completed counter 255 // at the end of a stop-world full GC. 256 unsigned int GenCollectedHeap::update_full_collections_completed() { 257 MonitorLocker ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag); 258 assert(_full_collections_completed <= _total_full_collections, 259 "Can't complete more collections than were started"); 260 _full_collections_completed = _total_full_collections; 261 ml.notify_all(); 262 return _full_collections_completed; 263 } 264 265 // Update the _full_collections_completed counter, as appropriate, 266 // at the end of a concurrent GC cycle. Note the conditional update 267 // below to allow this method to be called by a concurrent collector 268 // without synchronizing in any manner with the VM thread (which 269 // may already have initiated a STW full collection "concurrently"). 270 unsigned int GenCollectedHeap::update_full_collections_completed(unsigned int count) { 271 MonitorLocker ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag); 272 assert((_full_collections_completed <= _total_full_collections) && 273 (count <= _total_full_collections), 274 "Can't complete more collections than were started"); 275 if (count > _full_collections_completed) { 276 _full_collections_completed = count; 277 ml.notify_all(); 278 } 279 return _full_collections_completed; 280 } 281 282 // Return true if any of the following is true: 283 // . the allocation won't fit into the current young gen heap 284 // . gc locker is occupied (jni critical section) 285 // . heap memory is tight -- the most recent previous collection 286 // was a full collection because a partial collection (would 287 // have) failed and is likely to fail again 288 bool GenCollectedHeap::should_try_older_generation_allocation(size_t word_size) const { 289 size_t young_capacity = _young_gen->capacity_before_gc(); 290 return (word_size > heap_word_size(young_capacity)) 291 || GCLocker::is_active_and_needs_gc() 292 || incremental_collection_failed(); 293 } 294 295 HeapWord* GenCollectedHeap::expand_heap_and_allocate(size_t size, bool is_tlab) { 296 HeapWord* result = NULL; 297 if (_old_gen->should_allocate(size, is_tlab)) { 298 result = _old_gen->expand_and_allocate(size, is_tlab); 299 } 300 if (result == NULL) { 301 if (_young_gen->should_allocate(size, is_tlab)) { 302 result = _young_gen->expand_and_allocate(size, is_tlab); 303 } 304 } 305 assert(result == NULL || is_in_reserved(result), "result not in heap"); 306 return result; 307 } 308 309 HeapWord* GenCollectedHeap::mem_allocate_work(size_t size, 310 bool is_tlab, 311 bool* gc_overhead_limit_was_exceeded) { 312 // In general gc_overhead_limit_was_exceeded should be false so 313 // set it so here and reset it to true only if the gc time 314 // limit is being exceeded as checked below. 315 *gc_overhead_limit_was_exceeded = false; 316 317 HeapWord* result = NULL; 318 319 // Loop until the allocation is satisfied, or unsatisfied after GC. 320 for (uint try_count = 1, gclocker_stalled_count = 0; /* return or throw */; try_count += 1) { 321 322 // First allocation attempt is lock-free. 323 Generation *young = _young_gen; 324 assert(young->supports_inline_contig_alloc(), 325 "Otherwise, must do alloc within heap lock"); 326 if (young->should_allocate(size, is_tlab)) { 327 result = young->par_allocate(size, is_tlab); 328 if (result != NULL) { 329 assert(is_in_reserved(result), "result not in heap"); 330 return result; 331 } 332 } 333 uint gc_count_before; // Read inside the Heap_lock locked region. 334 { 335 MutexLocker ml(Heap_lock); 336 log_trace(gc, alloc)("GenCollectedHeap::mem_allocate_work: attempting locked slow path allocation"); 337 // Note that only large objects get a shot at being 338 // allocated in later generations. 339 bool first_only = !should_try_older_generation_allocation(size); 340 341 result = attempt_allocation(size, is_tlab, first_only); 342 if (result != NULL) { 343 assert(is_in_reserved(result), "result not in heap"); 344 return result; 345 } 346 347 if (GCLocker::is_active_and_needs_gc()) { 348 if (is_tlab) { 349 return NULL; // Caller will retry allocating individual object. 350 } 351 if (!is_maximal_no_gc()) { 352 // Try and expand heap to satisfy request. 353 result = expand_heap_and_allocate(size, is_tlab); 354 // Result could be null if we are out of space. 355 if (result != NULL) { 356 return result; 357 } 358 } 359 360 if (gclocker_stalled_count > GCLockerRetryAllocationCount) { 361 return NULL; // We didn't get to do a GC and we didn't get any memory. 362 } 363 364 // If this thread is not in a jni critical section, we stall 365 // the requestor until the critical section has cleared and 366 // GC allowed. When the critical section clears, a GC is 367 // initiated by the last thread exiting the critical section; so 368 // we retry the allocation sequence from the beginning of the loop, 369 // rather than causing more, now probably unnecessary, GC attempts. 370 JavaThread* jthr = JavaThread::current(); 371 if (!jthr->in_critical()) { 372 MutexUnlocker mul(Heap_lock); 373 // Wait for JNI critical section to be exited 374 GCLocker::stall_until_clear(); 375 gclocker_stalled_count += 1; 376 continue; 377 } else { 378 if (CheckJNICalls) { 379 fatal("Possible deadlock due to allocating while" 380 " in jni critical section"); 381 } 382 return NULL; 383 } 384 } 385 386 // Read the gc count while the heap lock is held. 387 gc_count_before = total_collections(); 388 } 389 390 VM_GenCollectForAllocation op(size, is_tlab, gc_count_before); 391 VMThread::execute(&op); 392 if (op.prologue_succeeded()) { 393 result = op.result(); 394 if (op.gc_locked()) { 395 assert(result == NULL, "must be NULL if gc_locked() is true"); 396 continue; // Retry and/or stall as necessary. 397 } 398 399 // Allocation has failed and a collection 400 // has been done. If the gc time limit was exceeded the 401 // this time, return NULL so that an out-of-memory 402 // will be thrown. Clear gc_overhead_limit_exceeded 403 // so that the overhead exceeded does not persist. 404 405 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded(); 406 const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear(); 407 408 if (limit_exceeded && softrefs_clear) { 409 *gc_overhead_limit_was_exceeded = true; 410 size_policy()->set_gc_overhead_limit_exceeded(false); 411 if (op.result() != NULL) { 412 CollectedHeap::fill_with_object(op.result(), size); 413 } 414 return NULL; 415 } 416 assert(result == NULL || is_in_reserved(result), 417 "result not in heap"); 418 return result; 419 } 420 421 // Give a warning if we seem to be looping forever. 422 if ((QueuedAllocationWarningCount > 0) && 423 (try_count % QueuedAllocationWarningCount == 0)) { 424 log_warning(gc, ergo)("GenCollectedHeap::mem_allocate_work retries %d times," 425 " size=" SIZE_FORMAT " %s", try_count, size, is_tlab ? "(TLAB)" : ""); 426 } 427 } 428 } 429 430 HeapWord* GenCollectedHeap::attempt_allocation(size_t size, 431 bool is_tlab, 432 bool first_only) { 433 HeapWord* res = NULL; 434 435 if (_young_gen->should_allocate(size, is_tlab)) { 436 res = _young_gen->allocate(size, is_tlab); 437 if (res != NULL || first_only) { 438 return res; 439 } 440 } 441 442 if (_old_gen->should_allocate(size, is_tlab)) { 443 res = _old_gen->allocate(size, is_tlab); 444 } 445 446 return res; 447 } 448 449 HeapWord* GenCollectedHeap::mem_allocate(size_t size, 450 bool* gc_overhead_limit_was_exceeded) { 451 return mem_allocate_work(size, 452 false /* is_tlab */, 453 gc_overhead_limit_was_exceeded); 454 } 455 456 bool GenCollectedHeap::must_clear_all_soft_refs() { 457 return _gc_cause == GCCause::_metadata_GC_clear_soft_refs || 458 _gc_cause == GCCause::_wb_full_gc; 459 } 460 461 void GenCollectedHeap::collect_generation(Generation* gen, bool full, size_t size, 462 bool is_tlab, bool run_verification, bool clear_soft_refs, 463 bool restore_marks_for_biased_locking) { 464 FormatBuffer<> title("Collect gen: %s", gen->short_name()); 465 GCTraceTime(Trace, gc, phases) t1(title); 466 TraceCollectorStats tcs(gen->counters()); 467 TraceMemoryManagerStats tmms(gen->gc_manager(), gc_cause()); 468 469 gen->stat_record()->invocations++; 470 gen->stat_record()->accumulated_time.start(); 471 472 // Must be done anew before each collection because 473 // a previous collection will do mangling and will 474 // change top of some spaces. 475 record_gen_tops_before_GC(); 476 477 log_trace(gc)("%s invoke=%d size=" SIZE_FORMAT, heap()->is_young_gen(gen) ? "Young" : "Old", gen->stat_record()->invocations, size * HeapWordSize); 478 479 if (run_verification && VerifyBeforeGC) { 480 Universe::verify("Before GC"); 481 } 482 COMPILER2_OR_JVMCI_PRESENT(DerivedPointerTable::clear()); 483 484 if (restore_marks_for_biased_locking) { 485 // We perform this mark word preservation work lazily 486 // because it's only at this point that we know whether we 487 // absolutely have to do it; we want to avoid doing it for 488 // scavenge-only collections where it's unnecessary 489 BiasedLocking::preserve_marks(); 490 } 491 492 // Do collection work 493 { 494 // Note on ref discovery: For what appear to be historical reasons, 495 // GCH enables and disabled (by enqueing) refs discovery. 496 // In the future this should be moved into the generation's 497 // collect method so that ref discovery and enqueueing concerns 498 // are local to a generation. The collect method could return 499 // an appropriate indication in the case that notification on 500 // the ref lock was needed. This will make the treatment of 501 // weak refs more uniform (and indeed remove such concerns 502 // from GCH). XXX 503 504 save_marks(); // save marks for all gens 505 // We want to discover references, but not process them yet. 506 // This mode is disabled in process_discovered_references if the 507 // generation does some collection work, or in 508 // enqueue_discovered_references if the generation returns 509 // without doing any work. 510 ReferenceProcessor* rp = gen->ref_processor(); 511 // If the discovery of ("weak") refs in this generation is 512 // atomic wrt other collectors in this configuration, we 513 // are guaranteed to have empty discovered ref lists. 514 if (rp->discovery_is_atomic()) { 515 rp->enable_discovery(); 516 rp->setup_policy(clear_soft_refs); 517 } else { 518 // collect() below will enable discovery as appropriate 519 } 520 gen->collect(full, clear_soft_refs, size, is_tlab); 521 if (!rp->enqueuing_is_done()) { 522 rp->disable_discovery(); 523 } else { 524 rp->set_enqueuing_is_done(false); 525 } 526 rp->verify_no_references_recorded(); 527 } 528 529 COMPILER2_OR_JVMCI_PRESENT(DerivedPointerTable::update_pointers()); 530 531 gen->stat_record()->accumulated_time.stop(); 532 533 update_gc_stats(gen, full); 534 535 if (run_verification && VerifyAfterGC) { 536 Universe::verify("After GC"); 537 } 538 } 539 540 void GenCollectedHeap::do_collection(bool full, 541 bool clear_all_soft_refs, 542 size_t size, 543 bool is_tlab, 544 GenerationType max_generation) { 545 ResourceMark rm; 546 DEBUG_ONLY(Thread* my_thread = Thread::current();) 547 548 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); 549 assert(my_thread->is_VM_thread() || 550 my_thread->is_ConcurrentGC_thread(), 551 "incorrect thread type capability"); 552 assert(Heap_lock->is_locked(), 553 "the requesting thread should have the Heap_lock"); 554 guarantee(!is_gc_active(), "collection is not reentrant"); 555 556 if (GCLocker::check_active_before_gc()) { 557 return; // GC is disabled (e.g. JNI GetXXXCritical operation) 558 } 559 560 const bool do_clear_all_soft_refs = clear_all_soft_refs || 561 soft_ref_policy()->should_clear_all_soft_refs(); 562 563 ClearedAllSoftRefs casr(do_clear_all_soft_refs, soft_ref_policy()); 564 565 AutoModifyRestore<bool> temporarily(_is_gc_active, true); 566 567 bool complete = full && (max_generation == OldGen); 568 bool old_collects_young = complete && !ScavengeBeforeFullGC; 569 bool do_young_collection = !old_collects_young && _young_gen->should_collect(full, size, is_tlab); 570 571 const PreGenGCValues pre_gc_values = get_pre_gc_values(); 572 573 bool run_verification = total_collections() >= VerifyGCStartAt; 574 bool prepared_for_verification = false; 575 bool do_full_collection = false; 576 577 if (do_young_collection) { 578 GCIdMark gc_id_mark; 579 GCTraceCPUTime tcpu; 580 GCTraceTime(Info, gc) t("Pause Young", NULL, gc_cause(), true); 581 582 print_heap_before_gc(); 583 584 if (run_verification && VerifyGCLevel <= 0 && VerifyBeforeGC) { 585 prepare_for_verify(); 586 prepared_for_verification = true; 587 } 588 589 gc_prologue(complete); 590 increment_total_collections(complete); 591 592 collect_generation(_young_gen, 593 full, 594 size, 595 is_tlab, 596 run_verification && VerifyGCLevel <= 0, 597 do_clear_all_soft_refs, 598 false); 599 600 if (size > 0 && (!is_tlab || _young_gen->supports_tlab_allocation()) && 601 size * HeapWordSize <= _young_gen->unsafe_max_alloc_nogc()) { 602 // Allocation request was met by young GC. 603 size = 0; 604 } 605 606 // Ask if young collection is enough. If so, do the final steps for young collection, 607 // and fallthrough to the end. 608 do_full_collection = should_do_full_collection(size, full, is_tlab, max_generation); 609 if (!do_full_collection) { 610 // Adjust generation sizes. 611 _young_gen->compute_new_size(); 612 613 print_heap_change(pre_gc_values); 614 615 // Track memory usage and detect low memory after GC finishes 616 MemoryService::track_memory_usage(); 617 618 gc_epilogue(complete); 619 } 620 621 print_heap_after_gc(); 622 623 } else { 624 // No young collection, ask if we need to perform Full collection. 625 do_full_collection = should_do_full_collection(size, full, is_tlab, max_generation); 626 } 627 628 if (do_full_collection) { 629 GCIdMark gc_id_mark; 630 GCTraceCPUTime tcpu; 631 GCTraceTime(Info, gc) t("Pause Full", NULL, gc_cause(), true); 632 633 print_heap_before_gc(); 634 635 if (!prepared_for_verification && run_verification && 636 VerifyGCLevel <= 1 && VerifyBeforeGC) { 637 prepare_for_verify(); 638 } 639 640 if (!do_young_collection) { 641 gc_prologue(complete); 642 increment_total_collections(complete); 643 } 644 645 // Accounting quirk: total full collections would be incremented when "complete" 646 // is set, by calling increment_total_collections above. However, we also need to 647 // account Full collections that had "complete" unset. 648 if (!complete) { 649 increment_total_full_collections(); 650 } 651 652 collect_generation(_old_gen, 653 full, 654 size, 655 is_tlab, 656 run_verification && VerifyGCLevel <= 1, 657 do_clear_all_soft_refs, 658 true); 659 660 // Adjust generation sizes. 661 _old_gen->compute_new_size(); 662 _young_gen->compute_new_size(); 663 664 // Delete metaspaces for unloaded class loaders and clean up loader_data graph 665 ClassLoaderDataGraph::purge(); 666 DEBUG_ONLY(MetaspaceUtils::verify(false);) 667 // Resize the metaspace capacity after full collections 668 MetaspaceGC::compute_new_size(); 669 update_full_collections_completed(); 670 671 print_heap_change(pre_gc_values); 672 673 // Track memory usage and detect low memory after GC finishes 674 MemoryService::track_memory_usage(); 675 676 // Need to tell the epilogue code we are done with Full GC, regardless what was 677 // the initial value for "complete" flag. 678 gc_epilogue(true); 679 680 BiasedLocking::restore_marks(); 681 682 print_heap_after_gc(); 683 } 684 } 685 686 bool GenCollectedHeap::should_do_full_collection(size_t size, bool full, bool is_tlab, 687 GenCollectedHeap::GenerationType max_gen) const { 688 return max_gen == OldGen && _old_gen->should_collect(full, size, is_tlab); 689 } 690 691 void GenCollectedHeap::register_nmethod(nmethod* nm) { 692 ScavengableNMethods::register_nmethod(nm); 693 } 694 695 void GenCollectedHeap::unregister_nmethod(nmethod* nm) { 696 ScavengableNMethods::unregister_nmethod(nm); 697 } 698 699 void GenCollectedHeap::verify_nmethod(nmethod* nm) { 700 ScavengableNMethods::verify_nmethod(nm); 701 } 702 703 void GenCollectedHeap::flush_nmethod(nmethod* nm) { 704 // Do nothing. 705 } 706 707 void GenCollectedHeap::prune_scavengable_nmethods() { 708 ScavengableNMethods::prune_nmethods(); 709 } 710 711 HeapWord* GenCollectedHeap::satisfy_failed_allocation(size_t size, bool is_tlab) { 712 GCCauseSetter x(this, GCCause::_allocation_failure); 713 HeapWord* result = NULL; 714 715 assert(size != 0, "Precondition violated"); 716 if (GCLocker::is_active_and_needs_gc()) { 717 // GC locker is active; instead of a collection we will attempt 718 // to expand the heap, if there's room for expansion. 719 if (!is_maximal_no_gc()) { 720 result = expand_heap_and_allocate(size, is_tlab); 721 } 722 return result; // Could be null if we are out of space. 723 } else if (!incremental_collection_will_fail(false /* don't consult_young */)) { 724 // Do an incremental collection. 725 do_collection(false, // full 726 false, // clear_all_soft_refs 727 size, // size 728 is_tlab, // is_tlab 729 GenCollectedHeap::OldGen); // max_generation 730 } else { 731 log_trace(gc)(" :: Trying full because partial may fail :: "); 732 // Try a full collection; see delta for bug id 6266275 733 // for the original code and why this has been simplified 734 // with from-space allocation criteria modified and 735 // such allocation moved out of the safepoint path. 736 do_collection(true, // full 737 false, // clear_all_soft_refs 738 size, // size 739 is_tlab, // is_tlab 740 GenCollectedHeap::OldGen); // max_generation 741 } 742 743 result = attempt_allocation(size, is_tlab, false /*first_only*/); 744 745 if (result != NULL) { 746 assert(is_in_reserved(result), "result not in heap"); 747 return result; 748 } 749 750 // OK, collection failed, try expansion. 751 result = expand_heap_and_allocate(size, is_tlab); 752 if (result != NULL) { 753 return result; 754 } 755 756 // If we reach this point, we're really out of memory. Try every trick 757 // we can to reclaim memory. Force collection of soft references. Force 758 // a complete compaction of the heap. Any additional methods for finding 759 // free memory should be here, especially if they are expensive. If this 760 // attempt fails, an OOM exception will be thrown. 761 { 762 UIntFlagSetting flag_change(MarkSweepAlwaysCompactCount, 1); // Make sure the heap is fully compacted 763 764 do_collection(true, // full 765 true, // clear_all_soft_refs 766 size, // size 767 is_tlab, // is_tlab 768 GenCollectedHeap::OldGen); // max_generation 769 } 770 771 result = attempt_allocation(size, is_tlab, false /* first_only */); 772 if (result != NULL) { 773 assert(is_in_reserved(result), "result not in heap"); 774 return result; 775 } 776 777 assert(!soft_ref_policy()->should_clear_all_soft_refs(), 778 "Flag should have been handled and cleared prior to this point"); 779 780 // What else? We might try synchronous finalization later. If the total 781 // space available is large enough for the allocation, then a more 782 // complete compaction phase than we've tried so far might be 783 // appropriate. 784 return NULL; 785 } 786 787 #ifdef ASSERT 788 class AssertNonScavengableClosure: public OopClosure { 789 public: 790 virtual void do_oop(oop* p) { 791 assert(!GenCollectedHeap::heap()->is_in_partial_collection(*p), 792 "Referent should not be scavengable."); } 793 virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); } 794 }; 795 static AssertNonScavengableClosure assert_is_non_scavengable_closure; 796 #endif 797 798 void GenCollectedHeap::process_roots(StrongRootsScope* scope, 799 ScanningOption so, 800 OopClosure* strong_roots, 801 CLDClosure* strong_cld_closure, 802 CLDClosure* weak_cld_closure, 803 CodeBlobToOopClosure* code_roots) { 804 // General roots. 805 assert(code_roots != NULL, "code root closure should always be set"); 806 // _n_termination for _process_strong_tasks should be set up stream 807 // in a method not running in a GC worker. Otherwise the GC worker 808 // could be trying to change the termination condition while the task 809 // is executing in another GC worker. 810 811 if (_process_strong_tasks->try_claim_task(GCH_PS_ClassLoaderDataGraph_oops_do)) { 812 ClassLoaderDataGraph::roots_cld_do(strong_cld_closure, weak_cld_closure); 813 } 814 815 // Only process code roots from thread stacks if we aren't visiting the entire CodeCache anyway 816 CodeBlobToOopClosure* roots_from_code_p = (so & SO_AllCodeCache) ? NULL : code_roots; 817 818 bool is_par = scope->n_threads() > 1; 819 Threads::possibly_parallel_oops_do(is_par, strong_roots, roots_from_code_p); 820 821 if (_process_strong_tasks->try_claim_task(GCH_PS_ObjectSynchronizer_oops_do)) { 822 ObjectSynchronizer::oops_do(strong_roots); 823 } 824 #if INCLUDE_AOT 825 if (UseAOT && _process_strong_tasks->try_claim_task(GCH_PS_aot_oops_do)) { 826 AOTLoader::oops_do(strong_roots); 827 } 828 #endif 829 if (_process_strong_tasks->try_claim_task(GCH_PS_OopStorageSet_oops_do)) { 830 OopStorageSet::strong_oops_do(strong_roots); 831 } 832 833 if (_process_strong_tasks->try_claim_task(GCH_PS_CodeCache_oops_do)) { 834 if (so & SO_ScavengeCodeCache) { 835 assert(code_roots != NULL, "must supply closure for code cache"); 836 837 // We only visit parts of the CodeCache when scavenging. 838 ScavengableNMethods::nmethods_do(code_roots); 839 } 840 if (so & SO_AllCodeCache) { 841 assert(code_roots != NULL, "must supply closure for code cache"); 842 843 // CMSCollector uses this to do intermediate-strength collections. 844 // We scan the entire code cache, since CodeCache::do_unloading is not called. 845 CodeCache::blobs_do(code_roots); 846 } 847 // Verify that the code cache contents are not subject to 848 // movement by a scavenging collection. 849 DEBUG_ONLY(CodeBlobToOopClosure assert_code_is_non_scavengable(&assert_is_non_scavengable_closure, !CodeBlobToOopClosure::FixRelocations)); 850 DEBUG_ONLY(ScavengableNMethods::asserted_non_scavengable_nmethods_do(&assert_code_is_non_scavengable)); 851 } 852 } 853 854 void GenCollectedHeap::young_process_roots(StrongRootsScope* scope, 855 OopsInGenClosure* root_closure, 856 OopsInGenClosure* old_gen_closure, 857 CLDClosure* cld_closure) { 858 MarkingCodeBlobClosure mark_code_closure(root_closure, CodeBlobToOopClosure::FixRelocations); 859 860 process_roots(scope, SO_ScavengeCodeCache, root_closure, 861 cld_closure, cld_closure, &mark_code_closure); 862 863 if (_process_strong_tasks->try_claim_task(GCH_PS_younger_gens)) { 864 root_closure->reset_generation(); 865 } 866 867 // When collection is parallel, all threads get to cooperate to do 868 // old generation scanning. 869 old_gen_closure->set_generation(_old_gen); 870 rem_set()->younger_refs_iterate(_old_gen, old_gen_closure, scope->n_threads()); 871 old_gen_closure->reset_generation(); 872 873 _process_strong_tasks->all_tasks_completed(scope->n_threads()); 874 } 875 876 void GenCollectedHeap::full_process_roots(StrongRootsScope* scope, 877 bool is_adjust_phase, 878 ScanningOption so, 879 bool only_strong_roots, 880 OopsInGenClosure* root_closure, 881 CLDClosure* cld_closure) { 882 MarkingCodeBlobClosure mark_code_closure(root_closure, is_adjust_phase); 883 CLDClosure* weak_cld_closure = only_strong_roots ? NULL : cld_closure; 884 885 process_roots(scope, so, root_closure, cld_closure, weak_cld_closure, &mark_code_closure); 886 _process_strong_tasks->all_tasks_completed(scope->n_threads()); 887 } 888 889 void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure) { 890 WeakProcessor::oops_do(root_closure); 891 _young_gen->ref_processor()->weak_oops_do(root_closure); 892 _old_gen->ref_processor()->weak_oops_do(root_closure); 893 } 894 895 bool GenCollectedHeap::no_allocs_since_save_marks() { 896 return _young_gen->no_allocs_since_save_marks() && 897 _old_gen->no_allocs_since_save_marks(); 898 } 899 900 bool GenCollectedHeap::supports_inline_contig_alloc() const { 901 return _young_gen->supports_inline_contig_alloc(); 902 } 903 904 HeapWord* volatile* GenCollectedHeap::top_addr() const { 905 return _young_gen->top_addr(); 906 } 907 908 HeapWord** GenCollectedHeap::end_addr() const { 909 return _young_gen->end_addr(); 910 } 911 912 // public collection interfaces 913 914 void GenCollectedHeap::collect(GCCause::Cause cause) { 915 if ((cause == GCCause::_wb_young_gc) || 916 (cause == GCCause::_gc_locker)) { 917 // Young collection for WhiteBox or GCLocker. 918 collect(cause, YoungGen); 919 } else { 920 #ifdef ASSERT 921 if (cause == GCCause::_scavenge_alot) { 922 // Young collection only. 923 collect(cause, YoungGen); 924 } else { 925 // Stop-the-world full collection. 926 collect(cause, OldGen); 927 } 928 #else 929 // Stop-the-world full collection. 930 collect(cause, OldGen); 931 #endif 932 } 933 } 934 935 void GenCollectedHeap::collect(GCCause::Cause cause, GenerationType max_generation) { 936 // The caller doesn't have the Heap_lock 937 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); 938 MutexLocker ml(Heap_lock); 939 collect_locked(cause, max_generation); 940 } 941 942 void GenCollectedHeap::collect_locked(GCCause::Cause cause) { 943 // The caller has the Heap_lock 944 assert(Heap_lock->owned_by_self(), "this thread should own the Heap_lock"); 945 collect_locked(cause, OldGen); 946 } 947 948 // this is the private collection interface 949 // The Heap_lock is expected to be held on entry. 950 951 void GenCollectedHeap::collect_locked(GCCause::Cause cause, GenerationType max_generation) { 952 // Read the GC count while holding the Heap_lock 953 unsigned int gc_count_before = total_collections(); 954 unsigned int full_gc_count_before = total_full_collections(); 955 956 if (GCLocker::should_discard(cause, gc_count_before)) { 957 return; 958 } 959 960 { 961 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back 962 VM_GenCollectFull op(gc_count_before, full_gc_count_before, 963 cause, max_generation); 964 VMThread::execute(&op); 965 } 966 } 967 968 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs) { 969 do_full_collection(clear_all_soft_refs, OldGen); 970 } 971 972 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs, 973 GenerationType last_generation) { 974 do_collection(true, // full 975 clear_all_soft_refs, // clear_all_soft_refs 976 0, // size 977 false, // is_tlab 978 last_generation); // last_generation 979 // Hack XXX FIX ME !!! 980 // A scavenge may not have been attempted, or may have 981 // been attempted and failed, because the old gen was too full 982 if (gc_cause() == GCCause::_gc_locker && incremental_collection_failed()) { 983 log_debug(gc, jni)("GC locker: Trying a full collection because scavenge failed"); 984 // This time allow the old gen to be collected as well 985 do_collection(true, // full 986 clear_all_soft_refs, // clear_all_soft_refs 987 0, // size 988 false, // is_tlab 989 OldGen); // last_generation 990 } 991 } 992 993 bool GenCollectedHeap::is_in_young(oop p) { 994 bool result = cast_from_oop<HeapWord*>(p) < _old_gen->reserved().start(); 995 assert(result == _young_gen->is_in_reserved(p), 996 "incorrect test - result=%d, p=" INTPTR_FORMAT, result, p2i((void*)p)); 997 return result; 998 } 999 1000 // Returns "TRUE" iff "p" points into the committed areas of the heap. 1001 bool GenCollectedHeap::is_in(const void* p) const { 1002 return _young_gen->is_in(p) || _old_gen->is_in(p); 1003 } 1004 1005 #ifdef ASSERT 1006 // Don't implement this by using is_in_young(). This method is used 1007 // in some cases to check that is_in_young() is correct. 1008 bool GenCollectedHeap::is_in_partial_collection(const void* p) { 1009 assert(is_in_reserved(p) || p == NULL, 1010 "Does not work if address is non-null and outside of the heap"); 1011 return p < _young_gen->reserved().end() && p != NULL; 1012 } 1013 #endif 1014 1015 void GenCollectedHeap::oop_iterate(OopIterateClosure* cl) { 1016 _young_gen->oop_iterate(cl); 1017 _old_gen->oop_iterate(cl); 1018 } 1019 1020 void GenCollectedHeap::object_iterate(ObjectClosure* cl) { 1021 _young_gen->object_iterate(cl); 1022 _old_gen->object_iterate(cl); 1023 } 1024 1025 Space* GenCollectedHeap::space_containing(const void* addr) const { 1026 Space* res = _young_gen->space_containing(addr); 1027 if (res != NULL) { 1028 return res; 1029 } 1030 res = _old_gen->space_containing(addr); 1031 assert(res != NULL, "Could not find containing space"); 1032 return res; 1033 } 1034 1035 HeapWord* GenCollectedHeap::block_start(const void* addr) const { 1036 assert(is_in_reserved(addr), "block_start of address outside of heap"); 1037 if (_young_gen->is_in_reserved(addr)) { 1038 assert(_young_gen->is_in(addr), "addr should be in allocated part of generation"); 1039 return _young_gen->block_start(addr); 1040 } 1041 1042 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address"); 1043 assert(_old_gen->is_in(addr), "addr should be in allocated part of generation"); 1044 return _old_gen->block_start(addr); 1045 } 1046 1047 bool GenCollectedHeap::block_is_obj(const HeapWord* addr) const { 1048 assert(is_in_reserved(addr), "block_is_obj of address outside of heap"); 1049 assert(block_start(addr) == addr, "addr must be a block start"); 1050 if (_young_gen->is_in_reserved(addr)) { 1051 return _young_gen->block_is_obj(addr); 1052 } 1053 1054 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address"); 1055 return _old_gen->block_is_obj(addr); 1056 } 1057 1058 bool GenCollectedHeap::supports_tlab_allocation() const { 1059 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!"); 1060 return _young_gen->supports_tlab_allocation(); 1061 } 1062 1063 size_t GenCollectedHeap::tlab_capacity(Thread* thr) const { 1064 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!"); 1065 if (_young_gen->supports_tlab_allocation()) { 1066 return _young_gen->tlab_capacity(); 1067 } 1068 return 0; 1069 } 1070 1071 size_t GenCollectedHeap::tlab_used(Thread* thr) const { 1072 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!"); 1073 if (_young_gen->supports_tlab_allocation()) { 1074 return _young_gen->tlab_used(); 1075 } 1076 return 0; 1077 } 1078 1079 size_t GenCollectedHeap::unsafe_max_tlab_alloc(Thread* thr) const { 1080 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!"); 1081 if (_young_gen->supports_tlab_allocation()) { 1082 return _young_gen->unsafe_max_tlab_alloc(); 1083 } 1084 return 0; 1085 } 1086 1087 HeapWord* GenCollectedHeap::allocate_new_tlab(size_t min_size, 1088 size_t requested_size, 1089 size_t* actual_size) { 1090 bool gc_overhead_limit_was_exceeded; 1091 HeapWord* result = mem_allocate_work(requested_size /* size */, 1092 true /* is_tlab */, 1093 &gc_overhead_limit_was_exceeded); 1094 if (result != NULL) { 1095 *actual_size = requested_size; 1096 } 1097 1098 return result; 1099 } 1100 1101 // Requires "*prev_ptr" to be non-NULL. Deletes and a block of minimal size 1102 // from the list headed by "*prev_ptr". 1103 static ScratchBlock *removeSmallestScratch(ScratchBlock **prev_ptr) { 1104 bool first = true; 1105 size_t min_size = 0; // "first" makes this conceptually infinite. 1106 ScratchBlock **smallest_ptr, *smallest; 1107 ScratchBlock *cur = *prev_ptr; 1108 while (cur) { 1109 assert(*prev_ptr == cur, "just checking"); 1110 if (first || cur->num_words < min_size) { 1111 smallest_ptr = prev_ptr; 1112 smallest = cur; 1113 min_size = smallest->num_words; 1114 first = false; 1115 } 1116 prev_ptr = &cur->next; 1117 cur = cur->next; 1118 } 1119 smallest = *smallest_ptr; 1120 *smallest_ptr = smallest->next; 1121 return smallest; 1122 } 1123 1124 // Sort the scratch block list headed by res into decreasing size order, 1125 // and set "res" to the result. 1126 static void sort_scratch_list(ScratchBlock*& list) { 1127 ScratchBlock* sorted = NULL; 1128 ScratchBlock* unsorted = list; 1129 while (unsorted) { 1130 ScratchBlock *smallest = removeSmallestScratch(&unsorted); 1131 smallest->next = sorted; 1132 sorted = smallest; 1133 } 1134 list = sorted; 1135 } 1136 1137 ScratchBlock* GenCollectedHeap::gather_scratch(Generation* requestor, 1138 size_t max_alloc_words) { 1139 ScratchBlock* res = NULL; 1140 _young_gen->contribute_scratch(res, requestor, max_alloc_words); 1141 _old_gen->contribute_scratch(res, requestor, max_alloc_words); 1142 sort_scratch_list(res); 1143 return res; 1144 } 1145 1146 void GenCollectedHeap::release_scratch() { 1147 _young_gen->reset_scratch(); 1148 _old_gen->reset_scratch(); 1149 } 1150 1151 class GenPrepareForVerifyClosure: public GenCollectedHeap::GenClosure { 1152 void do_generation(Generation* gen) { 1153 gen->prepare_for_verify(); 1154 } 1155 }; 1156 1157 void GenCollectedHeap::prepare_for_verify() { 1158 ensure_parsability(false); // no need to retire TLABs 1159 GenPrepareForVerifyClosure blk; 1160 generation_iterate(&blk, false); 1161 } 1162 1163 void GenCollectedHeap::generation_iterate(GenClosure* cl, 1164 bool old_to_young) { 1165 if (old_to_young) { 1166 cl->do_generation(_old_gen); 1167 cl->do_generation(_young_gen); 1168 } else { 1169 cl->do_generation(_young_gen); 1170 cl->do_generation(_old_gen); 1171 } 1172 } 1173 1174 bool GenCollectedHeap::is_maximal_no_gc() const { 1175 return _young_gen->is_maximal_no_gc() && _old_gen->is_maximal_no_gc(); 1176 } 1177 1178 void GenCollectedHeap::save_marks() { 1179 _young_gen->save_marks(); 1180 _old_gen->save_marks(); 1181 } 1182 1183 GenCollectedHeap* GenCollectedHeap::heap() { 1184 // SerialHeap is the only subtype of GenCollectedHeap. 1185 return named_heap<GenCollectedHeap>(CollectedHeap::Serial); 1186 } 1187 1188 #if INCLUDE_SERIALGC 1189 void GenCollectedHeap::prepare_for_compaction() { 1190 // Start by compacting into same gen. 1191 CompactPoint cp(_old_gen); 1192 _old_gen->prepare_for_compaction(&cp); 1193 _young_gen->prepare_for_compaction(&cp); 1194 } 1195 #endif // INCLUDE_SERIALGC 1196 1197 void GenCollectedHeap::verify(VerifyOption option /* ignored */) { 1198 log_debug(gc, verify)("%s", _old_gen->name()); 1199 _old_gen->verify(); 1200 1201 log_debug(gc, verify)("%s", _old_gen->name()); 1202 _young_gen->verify(); 1203 1204 log_debug(gc, verify)("RemSet"); 1205 rem_set()->verify(); 1206 } 1207 1208 void GenCollectedHeap::print_on(outputStream* st) const { 1209 if (_young_gen != NULL) { 1210 _young_gen->print_on(st); 1211 } 1212 if (_old_gen != NULL) { 1213 _old_gen->print_on(st); 1214 } 1215 MetaspaceUtils::print_on(st); 1216 } 1217 1218 void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const { 1219 } 1220 1221 bool GenCollectedHeap::print_location(outputStream* st, void* addr) const { 1222 return BlockLocationPrinter<GenCollectedHeap>::print_location(st, addr); 1223 } 1224 1225 void GenCollectedHeap::print_tracing_info() const { 1226 if (log_is_enabled(Debug, gc, heap, exit)) { 1227 LogStreamHandle(Debug, gc, heap, exit) lsh; 1228 _young_gen->print_summary_info_on(&lsh); 1229 _old_gen->print_summary_info_on(&lsh); 1230 } 1231 } 1232 1233 void GenCollectedHeap::print_heap_change(const PreGenGCValues& pre_gc_values) const { 1234 const DefNewGeneration* const def_new_gen = (DefNewGeneration*) young_gen(); 1235 1236 log_info(gc, heap)(HEAP_CHANGE_FORMAT" " 1237 HEAP_CHANGE_FORMAT" " 1238 HEAP_CHANGE_FORMAT, 1239 HEAP_CHANGE_FORMAT_ARGS(def_new_gen->short_name(), 1240 pre_gc_values.young_gen_used(), 1241 pre_gc_values.young_gen_capacity(), 1242 def_new_gen->used(), 1243 def_new_gen->capacity()), 1244 HEAP_CHANGE_FORMAT_ARGS("Eden", 1245 pre_gc_values.eden_used(), 1246 pre_gc_values.eden_capacity(), 1247 def_new_gen->eden()->used(), 1248 def_new_gen->eden()->capacity()), 1249 HEAP_CHANGE_FORMAT_ARGS("From", 1250 pre_gc_values.from_used(), 1251 pre_gc_values.from_capacity(), 1252 def_new_gen->from()->used(), 1253 def_new_gen->from()->capacity())); 1254 log_info(gc, heap)(HEAP_CHANGE_FORMAT, 1255 HEAP_CHANGE_FORMAT_ARGS(old_gen()->short_name(), 1256 pre_gc_values.old_gen_used(), 1257 pre_gc_values.old_gen_capacity(), 1258 old_gen()->used(), 1259 old_gen()->capacity())); 1260 MetaspaceUtils::print_metaspace_change(pre_gc_values.metaspace_sizes()); 1261 } 1262 1263 class GenGCPrologueClosure: public GenCollectedHeap::GenClosure { 1264 private: 1265 bool _full; 1266 public: 1267 void do_generation(Generation* gen) { 1268 gen->gc_prologue(_full); 1269 } 1270 GenGCPrologueClosure(bool full) : _full(full) {}; 1271 }; 1272 1273 void GenCollectedHeap::gc_prologue(bool full) { 1274 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer"); 1275 1276 // Fill TLAB's and such 1277 ensure_parsability(true); // retire TLABs 1278 1279 // Walk generations 1280 GenGCPrologueClosure blk(full); 1281 generation_iterate(&blk, false); // not old-to-young. 1282 }; 1283 1284 class GenGCEpilogueClosure: public GenCollectedHeap::GenClosure { 1285 private: 1286 bool _full; 1287 public: 1288 void do_generation(Generation* gen) { 1289 gen->gc_epilogue(_full); 1290 } 1291 GenGCEpilogueClosure(bool full) : _full(full) {}; 1292 }; 1293 1294 void GenCollectedHeap::gc_epilogue(bool full) { 1295 #if COMPILER2_OR_JVMCI 1296 assert(DerivedPointerTable::is_empty(), "derived pointer present"); 1297 size_t actual_gap = pointer_delta((HeapWord*) (max_uintx-3), *(end_addr())); 1298 guarantee(is_client_compilation_mode_vm() || actual_gap > (size_t)FastAllocateSizeLimit, "inline allocation wraps"); 1299 #endif // COMPILER2_OR_JVMCI 1300 1301 resize_all_tlabs(); 1302 1303 GenGCEpilogueClosure blk(full); 1304 generation_iterate(&blk, false); // not old-to-young. 1305 1306 if (!CleanChunkPoolAsync) { 1307 Chunk::clean_chunk_pool(); 1308 } 1309 1310 MetaspaceCounters::update_performance_counters(); 1311 CompressedClassSpaceCounters::update_performance_counters(); 1312 }; 1313 1314 #ifndef PRODUCT 1315 class GenGCSaveTopsBeforeGCClosure: public GenCollectedHeap::GenClosure { 1316 private: 1317 public: 1318 void do_generation(Generation* gen) { 1319 gen->record_spaces_top(); 1320 } 1321 }; 1322 1323 void GenCollectedHeap::record_gen_tops_before_GC() { 1324 if (ZapUnusedHeapArea) { 1325 GenGCSaveTopsBeforeGCClosure blk; 1326 generation_iterate(&blk, false); // not old-to-young. 1327 } 1328 } 1329 #endif // not PRODUCT 1330 1331 class GenEnsureParsabilityClosure: public GenCollectedHeap::GenClosure { 1332 public: 1333 void do_generation(Generation* gen) { 1334 gen->ensure_parsability(); 1335 } 1336 }; 1337 1338 void GenCollectedHeap::ensure_parsability(bool retire_tlabs) { 1339 CollectedHeap::ensure_parsability(retire_tlabs); 1340 GenEnsureParsabilityClosure ep_cl; 1341 generation_iterate(&ep_cl, false); 1342 } 1343 1344 oop GenCollectedHeap::handle_failed_promotion(Generation* old_gen, 1345 oop obj, 1346 size_t obj_size) { 1347 guarantee(old_gen == _old_gen, "We only get here with an old generation"); 1348 assert(obj_size == (size_t)obj->size(), "bad obj_size passed in"); 1349 HeapWord* result = NULL; 1350 1351 result = old_gen->expand_and_allocate(obj_size, false); 1352 1353 if (result != NULL) { 1354 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(obj), result, obj_size); 1355 } 1356 return oop(result); 1357 }