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