1 /* 2 * Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/symbolTable.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "code/icBuffer.hpp" 30 #include "gc_implementation/shared/collectorCounters.hpp" 31 #include "gc_implementation/shared/gcTrace.hpp" 32 #include "gc_implementation/shared/gcTraceTime.hpp" 33 #include "gc_implementation/shared/vmGCOperations.hpp" 34 #include "gc_interface/collectedHeap.inline.hpp" 35 #include "memory/filemap.hpp" 36 #include "memory/gcLocker.inline.hpp" 37 #include "memory/genCollectedHeap.hpp" 38 #include "memory/genOopClosures.inline.hpp" 39 #include "memory/generation.inline.hpp" 40 #include "memory/generationSpec.hpp" 41 #include "memory/resourceArea.hpp" 42 #include "memory/sharedHeap.hpp" 43 #include "memory/space.hpp" 44 #include "oops/oop.inline.hpp" 45 #include "oops/oop.inline2.hpp" 46 #include "runtime/biasedLocking.hpp" 47 #include "runtime/fprofiler.hpp" 48 #include "runtime/handles.hpp" 49 #include "runtime/handles.inline.hpp" 50 #include "runtime/java.hpp" 51 #include "runtime/vmThread.hpp" 52 #include "services/memoryService.hpp" 53 #include "utilities/vmError.hpp" 54 #include "utilities/workgroup.hpp" 55 #include "utilities/macros.hpp" 56 #if INCLUDE_ALL_GCS 57 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp" 58 #include "gc_implementation/concurrentMarkSweep/vmCMSOperations.hpp" 59 #endif // INCLUDE_ALL_GCS 60 61 GenCollectedHeap* GenCollectedHeap::_gch; 62 NOT_PRODUCT(size_t GenCollectedHeap::_skip_header_HeapWords = 0;) 63 64 // The set of potentially parallel tasks in root scanning. 65 enum GCH_strong_roots_tasks { 66 // We probably want to parallelize both of these internally, but for now... 67 GCH_PS_younger_gens, 68 // Leave this one last. 69 GCH_PS_NumElements 70 }; 71 72 GenCollectedHeap::GenCollectedHeap(GenCollectorPolicy *policy) : 73 SharedHeap(policy), 74 _gen_policy(policy), 75 _gen_process_roots_tasks(new SubTasksDone(GCH_PS_NumElements)), 76 _full_collections_completed(0) 77 { 78 if (_gen_process_roots_tasks == NULL || 79 !_gen_process_roots_tasks->valid()) { 80 vm_exit_during_initialization("Failed necessary allocation."); 81 } 82 assert(policy != NULL, "Sanity check"); 83 } 84 85 jint GenCollectedHeap::initialize() { 86 CollectedHeap::pre_initialize(); 87 88 int i; 89 _n_gens = gen_policy()->number_of_generations(); 90 91 // While there are no constraints in the GC code that HeapWordSize 92 // be any particular value, there are multiple other areas in the 93 // system which believe this to be true (e.g. oop->object_size in some 94 // cases incorrectly returns the size in wordSize units rather than 95 // HeapWordSize). 96 guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize"); 97 98 // Allocate space for the heap. 99 100 char* heap_address; 101 size_t total_reserved = 0; 102 int n_covered_regions = 0; 103 ReservedSpace heap_rs; 104 105 size_t heap_alignment = collector_policy()->heap_alignment(); 106 107 heap_address = allocate(heap_alignment, &total_reserved, 108 &n_covered_regions, &heap_rs); 109 110 if (!heap_rs.is_reserved()) { 111 vm_shutdown_during_initialization( 112 "Could not reserve enough space for object heap"); 113 return JNI_ENOMEM; 114 } 115 116 initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*)(heap_rs.base() + heap_rs.size())); 117 118 _rem_set = collector_policy()->create_rem_set(reserved_region(), n_covered_regions); 119 set_barrier_set(rem_set()->bs()); 120 121 _gch = this; 122 123 ReservedSpace young_rs = heap_rs.first_part(gen_policy()->young_gen_spec()->max_size(), false, false); 124 _young_gen = gen_policy()->young_gen_spec()->init(young_rs, 0, rem_set()); 125 heap_rs = heap_rs.last_part(gen_policy()->young_gen_spec()->max_size()); 126 127 ReservedSpace old_rs = heap_rs.first_part(gen_policy()->old_gen_spec()->max_size(), false, false); 128 _old_gen = gen_policy()->old_gen_spec()->init(old_rs, 1, rem_set()); 129 heap_rs = heap_rs.last_part(gen_policy()->old_gen_spec()->max_size()); 130 131 clear_incremental_collection_failed(); 132 133 #if INCLUDE_ALL_GCS 134 // If we are running CMS, create the collector responsible 135 // for collecting the CMS generations. 136 if (collector_policy()->is_concurrent_mark_sweep_policy()) { 137 bool success = create_cms_collector(); 138 if (!success) return JNI_ENOMEM; 139 } 140 #endif // INCLUDE_ALL_GCS 141 142 return JNI_OK; 143 } 144 145 char* GenCollectedHeap::allocate(size_t alignment, 146 size_t* _total_reserved, 147 int* _n_covered_regions, 148 ReservedSpace* heap_rs){ 149 const char overflow_msg[] = "The size of the object heap + VM data exceeds " 150 "the maximum representable size"; 151 152 // Now figure out the total size. 153 const size_t pageSize = UseLargePages ? os::large_page_size() : os::vm_page_size(); 154 assert(alignment % pageSize == 0, "Must be"); 155 156 size_t total_reserved = gen_policy()->young_gen_spec()->max_size() + 157 gen_policy()->old_gen_spec()->max_size(); 158 if (total_reserved < gen_policy()->young_gen_spec()->max_size() || 159 total_reserved < gen_policy()->old_gen_spec()->max_size()) { 160 vm_exit_during_initialization(overflow_msg); 161 } 162 assert(total_reserved % alignment == 0, 163 err_msg("Gen size; total_reserved=" SIZE_FORMAT ", alignment=" 164 SIZE_FORMAT, total_reserved, alignment)); 165 166 int n_covered_regions = gen_policy()->young_gen_spec()->n_covered_regions() + 167 gen_policy()->old_gen_spec()->n_covered_regions(); 168 169 // Needed until the cardtable is fixed to have the right number 170 // of covered regions. 171 n_covered_regions += 2; 172 173 *_total_reserved = total_reserved; 174 *_n_covered_regions = n_covered_regions; 175 176 *heap_rs = Universe::reserve_heap(total_reserved, alignment); 177 return heap_rs->base(); 178 } 179 180 void GenCollectedHeap::post_initialize() { 181 SharedHeap::post_initialize(); 182 GenCollectorPolicy *policy = (GenCollectorPolicy *)collector_policy(); 183 guarantee(policy->is_generation_policy(), "Illegal policy type"); 184 DefNewGeneration* def_new_gen = (DefNewGeneration*) _young_gen; 185 assert(def_new_gen->kind() == Generation::DefNew || 186 def_new_gen->kind() == Generation::ParNew, 187 "Wrong generation kind"); 188 189 assert(_old_gen->kind() == Generation::ConcurrentMarkSweep || 190 _old_gen->kind() == Generation::MarkSweepCompact, 191 "Wrong generation kind"); 192 193 policy->initialize_size_policy(def_new_gen->eden()->capacity(), 194 _old_gen->capacity(), 195 def_new_gen->from()->capacity()); 196 policy->initialize_gc_policy_counters(); 197 } 198 199 void GenCollectedHeap::ref_processing_init() { 200 SharedHeap::ref_processing_init(); 201 _young_gen->ref_processor_init(); 202 _old_gen->ref_processor_init(); 203 } 204 205 size_t GenCollectedHeap::capacity() const { 206 return _young_gen->capacity() + _old_gen->capacity(); 207 } 208 209 size_t GenCollectedHeap::used() const { 210 return _young_gen->used() + _old_gen->used(); 211 } 212 213 // Save the "used_region" for generations level and lower. 214 void GenCollectedHeap::save_used_regions(int level) { 215 assert(level < _n_gens, "Illegal level parameter"); 216 if (level == 1) { 217 _old_gen->save_used_region(); 218 } 219 _young_gen->save_used_region(); 220 } 221 222 size_t GenCollectedHeap::max_capacity() const { 223 return _young_gen->max_capacity() + _old_gen->max_capacity(); 224 } 225 226 // Update the _full_collections_completed counter 227 // at the end of a stop-world full GC. 228 unsigned int GenCollectedHeap::update_full_collections_completed() { 229 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag); 230 assert(_full_collections_completed <= _total_full_collections, 231 "Can't complete more collections than were started"); 232 _full_collections_completed = _total_full_collections; 233 ml.notify_all(); 234 return _full_collections_completed; 235 } 236 237 // Update the _full_collections_completed counter, as appropriate, 238 // at the end of a concurrent GC cycle. Note the conditional update 239 // below to allow this method to be called by a concurrent collector 240 // without synchronizing in any manner with the VM thread (which 241 // may already have initiated a STW full collection "concurrently"). 242 unsigned int GenCollectedHeap::update_full_collections_completed(unsigned int count) { 243 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag); 244 assert((_full_collections_completed <= _total_full_collections) && 245 (count <= _total_full_collections), 246 "Can't complete more collections than were started"); 247 if (count > _full_collections_completed) { 248 _full_collections_completed = count; 249 ml.notify_all(); 250 } 251 return _full_collections_completed; 252 } 253 254 255 #ifndef PRODUCT 256 // Override of memory state checking method in CollectedHeap: 257 // Some collectors (CMS for example) can't have badHeapWordVal written 258 // in the first two words of an object. (For instance , in the case of 259 // CMS these words hold state used to synchronize between certain 260 // (concurrent) GC steps and direct allocating mutators.) 261 // The skip_header_HeapWords() method below, allows us to skip 262 // over the requisite number of HeapWord's. Note that (for 263 // generational collectors) this means that those many words are 264 // skipped in each object, irrespective of the generation in which 265 // that object lives. The resultant loss of precision seems to be 266 // harmless and the pain of avoiding that imprecision appears somewhat 267 // higher than we are prepared to pay for such rudimentary debugging 268 // support. 269 void GenCollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, 270 size_t size) { 271 if (CheckMemoryInitialization && ZapUnusedHeapArea) { 272 // We are asked to check a size in HeapWords, 273 // but the memory is mangled in juint words. 274 juint* start = (juint*) (addr + skip_header_HeapWords()); 275 juint* end = (juint*) (addr + size); 276 for (juint* slot = start; slot < end; slot += 1) { 277 assert(*slot == badHeapWordVal, 278 "Found non badHeapWordValue in pre-allocation check"); 279 } 280 } 281 } 282 #endif 283 284 HeapWord* GenCollectedHeap::attempt_allocation(size_t size, 285 bool is_tlab, 286 bool first_only) { 287 HeapWord* res = NULL; 288 289 if (_young_gen->should_allocate(size, is_tlab)) { 290 res = _young_gen->allocate(size, is_tlab); 291 if (res != NULL || first_only) { 292 return res; 293 } 294 } 295 296 if (_old_gen->should_allocate(size, is_tlab)) { 297 res = _old_gen->allocate(size, is_tlab); 298 } 299 300 return res; 301 } 302 303 HeapWord* GenCollectedHeap::mem_allocate(size_t size, 304 bool* gc_overhead_limit_was_exceeded) { 305 return collector_policy()->mem_allocate_work(size, 306 false /* is_tlab */, 307 gc_overhead_limit_was_exceeded); 308 } 309 310 bool GenCollectedHeap::must_clear_all_soft_refs() { 311 return _gc_cause == GCCause::_last_ditch_collection; 312 } 313 314 bool GenCollectedHeap::should_do_concurrent_full_gc(GCCause::Cause cause) { 315 return UseConcMarkSweepGC && 316 ((cause == GCCause::_gc_locker && GCLockerInvokesConcurrent) || 317 (cause == GCCause::_java_lang_system_gc && ExplicitGCInvokesConcurrent)); 318 } 319 320 void GenCollectedHeap::collect_generation(Generation* gen, bool full, size_t size, 321 bool is_tlab, bool run_verification, bool clear_soft_refs) { 322 // Timer for individual generations. Last argument is false: no CR 323 // FIXME: We should try to start the timing earlier to cover more of the GC pause 324 // The PrintGCDetails logging starts before we have incremented the GC id. We will do that later 325 // so we can assume here that the next GC id is what we want. 326 GCTraceTime t1(gen->short_name(), PrintGCDetails, false, NULL, GCId::peek()); 327 TraceCollectorStats tcs(gen->counters()); 328 TraceMemoryManagerStats tmms(gen->kind(),gc_cause()); 329 330 size_t prev_used = gen->used(); 331 gen->stat_record()->invocations++; 332 gen->stat_record()->accumulated_time.start(); 333 334 // Must be done anew before each collection because 335 // a previous collection will do mangling and will 336 // change top of some spaces. 337 record_gen_tops_before_GC(); 338 339 if (PrintGC && Verbose) { 340 gclog_or_tty->print("level=%d invoke=%d size=" SIZE_FORMAT, 341 gen->level(), 342 gen->stat_record()->invocations, 343 size * HeapWordSize); 344 } 345 346 if (run_verification && VerifyBeforeGC) { 347 HandleMark hm; // Discard invalid handles created during verification 348 Universe::verify(" VerifyBeforeGC:"); 349 } 350 COMPILER2_PRESENT(DerivedPointerTable::clear()); 351 352 // Do collection work 353 { 354 // Note on ref discovery: For what appear to be historical reasons, 355 // GCH enables and disabled (by enqueing) refs discovery. 356 // In the future this should be moved into the generation's 357 // collect method so that ref discovery and enqueueing concerns 358 // are local to a generation. The collect method could return 359 // an appropriate indication in the case that notification on 360 // the ref lock was needed. This will make the treatment of 361 // weak refs more uniform (and indeed remove such concerns 362 // from GCH). XXX 363 364 HandleMark hm; // Discard invalid handles created during gc 365 save_marks(); // save marks for all gens 366 // We want to discover references, but not process them yet. 367 // This mode is disabled in process_discovered_references if the 368 // generation does some collection work, or in 369 // enqueue_discovered_references if the generation returns 370 // without doing any work. 371 ReferenceProcessor* rp = gen->ref_processor(); 372 // If the discovery of ("weak") refs in this generation is 373 // atomic wrt other collectors in this configuration, we 374 // are guaranteed to have empty discovered ref lists. 375 if (rp->discovery_is_atomic()) { 376 rp->enable_discovery(true /*verify_disabled*/, true /*verify_no_refs*/); 377 rp->setup_policy(clear_soft_refs); 378 } else { 379 // collect() below will enable discovery as appropriate 380 } 381 gen->collect(full, clear_soft_refs, size, is_tlab); 382 if (!rp->enqueuing_is_done()) { 383 rp->enqueue_discovered_references(); 384 } else { 385 rp->set_enqueuing_is_done(false); 386 } 387 rp->verify_no_references_recorded(); 388 } 389 390 // Determine if allocation request was met. 391 if (size > 0) { 392 if (!is_tlab || gen->supports_tlab_allocation()) { 393 if (size * HeapWordSize <= gen->unsafe_max_alloc_nogc()) { 394 size = 0; 395 } 396 } 397 } 398 399 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); 400 401 gen->stat_record()->accumulated_time.stop(); 402 403 update_gc_stats(gen->level(), full); 404 405 if (run_verification && VerifyAfterGC) { 406 HandleMark hm; // Discard invalid handles created during verification 407 Universe::verify(" VerifyAfterGC:"); 408 } 409 410 if (PrintGCDetails) { 411 gclog_or_tty->print(":"); 412 gen->print_heap_change(prev_used); 413 } 414 } 415 416 void GenCollectedHeap::do_collection(bool full, 417 bool clear_all_soft_refs, 418 size_t size, 419 bool is_tlab, 420 int max_level) { 421 ResourceMark rm; 422 DEBUG_ONLY(Thread* my_thread = Thread::current();) 423 424 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); 425 assert(my_thread->is_VM_thread() || 426 my_thread->is_ConcurrentGC_thread(), 427 "incorrect thread type capability"); 428 assert(Heap_lock->is_locked(), 429 "the requesting thread should have the Heap_lock"); 430 guarantee(!is_gc_active(), "collection is not reentrant"); 431 assert(max_level < n_gens(), "sanity check"); 432 433 if (GC_locker::check_active_before_gc()) { 434 return; // GC is disabled (e.g. JNI GetXXXCritical operation) 435 } 436 437 const bool do_clear_all_soft_refs = clear_all_soft_refs || 438 collector_policy()->should_clear_all_soft_refs(); 439 440 ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy()); 441 442 const size_t metadata_prev_used = MetaspaceAux::used_bytes(); 443 444 print_heap_before_gc(); 445 446 { 447 FlagSetting fl(_is_gc_active, true); 448 449 bool complete = full && (max_level == (n_gens()-1)); 450 const char* gc_cause_prefix = complete ? "Full GC" : "GC"; 451 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); 452 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); 453 // The PrintGCDetails logging starts before we have incremented the GC id. We will do that later 454 // so we can assume here that the next GC id is what we want. 455 GCTraceTime t(GCCauseString(gc_cause_prefix, gc_cause()), PrintGCDetails, false, NULL, GCId::peek()); 456 457 gc_prologue(complete); 458 increment_total_collections(complete); 459 460 size_t gch_prev_used = used(); 461 bool must_restore_marks_for_biased_locking = false; 462 bool run_verification = total_collections() >= VerifyGCStartAt; 463 464 if (_young_gen->performs_in_place_marking() || 465 _old_gen->performs_in_place_marking()) { 466 // We want to avoid doing this for 467 // scavenge-only collections where it's unnecessary. 468 must_restore_marks_for_biased_locking = true; 469 BiasedLocking::preserve_marks(); 470 } 471 472 bool prepared_for_verification = false; 473 int max_level_collected = 0; 474 if (!(full && _old_gen->full_collects_younger_generations()) && 475 _young_gen->should_collect(full, size, is_tlab)) { 476 if (run_verification && VerifyGCLevel <= 0 && VerifyBeforeGC) { 477 prepare_for_verify(); 478 prepared_for_verification = true; 479 } 480 collect_generation(_young_gen, full, size, is_tlab, run_verification && VerifyGCLevel <= 0, do_clear_all_soft_refs); 481 } 482 if (max_level == 1 && _old_gen->should_collect(full, size, is_tlab)) { 483 if (!complete) { 484 // The full_collections increment was missed above. 485 increment_total_full_collections(); 486 } 487 pre_full_gc_dump(NULL); // do any pre full gc dumps 488 if (run_verification && VerifyGCLevel <= 1 && VerifyBeforeGC) { 489 if (!prepared_for_verification) { 490 prepare_for_verify(); 491 } 492 } 493 collect_generation(_old_gen, full, size, is_tlab, run_verification && VerifyGCLevel <= 1, do_clear_all_soft_refs); 494 max_level_collected = 1; 495 } 496 497 // Update "complete" boolean wrt what actually transpired -- 498 // for instance, a promotion failure could have led to 499 // a whole heap collection. 500 complete = complete || (max_level_collected == n_gens() - 1); 501 502 if (complete) { // We did a "major" collection 503 // FIXME: See comment at pre_full_gc_dump call 504 post_full_gc_dump(NULL); // do any post full gc dumps 505 } 506 507 if (PrintGCDetails) { 508 print_heap_change(gch_prev_used); 509 510 // Print metaspace info for full GC with PrintGCDetails flag. 511 if (complete) { 512 MetaspaceAux::print_metaspace_change(metadata_prev_used); 513 } 514 } 515 516 // Adjust generation sizes. 517 if (max_level_collected == 1) { 518 _old_gen->compute_new_size(); 519 } 520 _young_gen->compute_new_size(); 521 522 if (complete) { 523 // Delete metaspaces for unloaded class loaders and clean up loader_data graph 524 ClassLoaderDataGraph::purge(); 525 MetaspaceAux::verify_metrics(); 526 // Resize the metaspace capacity after full collections 527 MetaspaceGC::compute_new_size(); 528 update_full_collections_completed(); 529 } 530 531 // Track memory usage and detect low memory after GC finishes 532 MemoryService::track_memory_usage(); 533 534 gc_epilogue(complete); 535 536 if (must_restore_marks_for_biased_locking) { 537 BiasedLocking::restore_marks(); 538 } 539 } 540 541 print_heap_after_gc(); 542 543 #ifdef TRACESPINNING 544 ParallelTaskTerminator::print_termination_counts(); 545 #endif 546 } 547 548 HeapWord* GenCollectedHeap::satisfy_failed_allocation(size_t size, bool is_tlab) { 549 return collector_policy()->satisfy_failed_allocation(size, is_tlab); 550 } 551 552 void GenCollectedHeap::set_par_threads(uint t) { 553 SharedHeap::set_par_threads(t); 554 _gen_process_roots_tasks->set_n_threads(t); 555 } 556 557 void GenCollectedHeap:: 558 gen_process_roots(int level, 559 bool younger_gens_as_roots, 560 bool activate_scope, 561 SharedHeap::ScanningOption so, 562 OopsInGenClosure* not_older_gens, 563 OopsInGenClosure* weak_roots, 564 OopsInGenClosure* older_gens, 565 CLDClosure* cld_closure, 566 CLDClosure* weak_cld_closure, 567 CodeBlobClosure* code_closure) { 568 569 // General roots. 570 SharedHeap::process_roots(activate_scope, so, 571 not_older_gens, weak_roots, 572 cld_closure, weak_cld_closure, 573 code_closure); 574 575 if (younger_gens_as_roots) { 576 if (!_gen_process_roots_tasks->is_task_claimed(GCH_PS_younger_gens)) { 577 if (level == 1) { 578 not_older_gens->set_generation(_young_gen); 579 _young_gen->oop_iterate(not_older_gens); 580 } 581 not_older_gens->reset_generation(); 582 } 583 } 584 // When collection is parallel, all threads get to cooperate to do 585 // older-gen scanning. 586 if (level == 0) { 587 older_gens->set_generation(_old_gen); 588 rem_set()->younger_refs_iterate(_old_gen, older_gens); 589 older_gens->reset_generation(); 590 } 591 592 _gen_process_roots_tasks->all_tasks_completed(); 593 } 594 595 void GenCollectedHeap:: 596 gen_process_roots(int level, 597 bool younger_gens_as_roots, 598 bool activate_scope, 599 SharedHeap::ScanningOption so, 600 bool only_strong_roots, 601 OopsInGenClosure* not_older_gens, 602 OopsInGenClosure* older_gens, 603 CLDClosure* cld_closure) { 604 605 const bool is_adjust_phase = !only_strong_roots && !younger_gens_as_roots; 606 607 bool is_moving_collection = false; 608 if (level == 0 || is_adjust_phase) { 609 // young collections are always moving 610 is_moving_collection = true; 611 } 612 613 MarkingCodeBlobClosure mark_code_closure(not_older_gens, is_moving_collection); 614 CodeBlobClosure* code_closure = &mark_code_closure; 615 616 gen_process_roots(level, 617 younger_gens_as_roots, 618 activate_scope, so, 619 not_older_gens, only_strong_roots ? NULL : not_older_gens, 620 older_gens, 621 cld_closure, only_strong_roots ? NULL : cld_closure, 622 code_closure); 623 624 } 625 626 void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure) { 627 SharedHeap::process_weak_roots(root_closure); 628 // "Local" "weak" refs 629 _young_gen->ref_processor()->weak_oops_do(root_closure); 630 _old_gen->ref_processor()->weak_oops_do(root_closure); 631 } 632 633 #define GCH_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix) \ 634 void GenCollectedHeap:: \ 635 oop_since_save_marks_iterate(int level, \ 636 OopClosureType* cur, \ 637 OopClosureType* older) { \ 638 if (level == 0) { \ 639 _young_gen->oop_since_save_marks_iterate##nv_suffix(cur); \ 640 _old_gen->oop_since_save_marks_iterate##nv_suffix(older); \ 641 } else { \ 642 _old_gen->oop_since_save_marks_iterate##nv_suffix(cur); \ 643 } \ 644 } 645 646 ALL_SINCE_SAVE_MARKS_CLOSURES(GCH_SINCE_SAVE_MARKS_ITERATE_DEFN) 647 648 #undef GCH_SINCE_SAVE_MARKS_ITERATE_DEFN 649 650 bool GenCollectedHeap::no_allocs_since_save_marks(int level) { 651 if (level == 0) { 652 if (!_young_gen->no_allocs_since_save_marks()) return false; 653 } 654 if (!_old_gen->no_allocs_since_save_marks()) return false; 655 return true; 656 } 657 658 bool GenCollectedHeap::supports_inline_contig_alloc() const { 659 return _young_gen->supports_inline_contig_alloc(); 660 } 661 662 HeapWord** GenCollectedHeap::top_addr() const { 663 return _young_gen->top_addr(); 664 } 665 666 HeapWord** GenCollectedHeap::end_addr() const { 667 return _young_gen->end_addr(); 668 } 669 670 // public collection interfaces 671 672 void GenCollectedHeap::collect(GCCause::Cause cause) { 673 if (should_do_concurrent_full_gc(cause)) { 674 #if INCLUDE_ALL_GCS 675 // mostly concurrent full collection 676 collect_mostly_concurrent(cause); 677 #else // INCLUDE_ALL_GCS 678 ShouldNotReachHere(); 679 #endif // INCLUDE_ALL_GCS 680 } else if (cause == GCCause::_wb_young_gc) { 681 // minor collection for WhiteBox API 682 collect(cause, 0); 683 } else { 684 #ifdef ASSERT 685 if (cause == GCCause::_scavenge_alot) { 686 // minor collection only 687 collect(cause, 0); 688 } else { 689 // Stop-the-world full collection 690 collect(cause, n_gens() - 1); 691 } 692 #else 693 // Stop-the-world full collection 694 collect(cause, n_gens() - 1); 695 #endif 696 } 697 } 698 699 void GenCollectedHeap::collect(GCCause::Cause cause, int max_level) { 700 // The caller doesn't have the Heap_lock 701 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); 702 MutexLocker ml(Heap_lock); 703 collect_locked(cause, max_level); 704 } 705 706 void GenCollectedHeap::collect_locked(GCCause::Cause cause) { 707 // The caller has the Heap_lock 708 assert(Heap_lock->owned_by_self(), "this thread should own the Heap_lock"); 709 collect_locked(cause, n_gens() - 1); 710 } 711 712 // this is the private collection interface 713 // The Heap_lock is expected to be held on entry. 714 715 void GenCollectedHeap::collect_locked(GCCause::Cause cause, int max_level) { 716 // Read the GC count while holding the Heap_lock 717 unsigned int gc_count_before = total_collections(); 718 unsigned int full_gc_count_before = total_full_collections(); 719 { 720 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back 721 VM_GenCollectFull op(gc_count_before, full_gc_count_before, 722 cause, max_level); 723 VMThread::execute(&op); 724 } 725 } 726 727 #if INCLUDE_ALL_GCS 728 bool GenCollectedHeap::create_cms_collector() { 729 730 assert(_old_gen->kind() == Generation::ConcurrentMarkSweep, 731 "Unexpected generation kinds"); 732 // Skip two header words in the block content verification 733 NOT_PRODUCT(_skip_header_HeapWords = CMSCollector::skip_header_HeapWords();) 734 CMSCollector* collector = new CMSCollector( 735 (ConcurrentMarkSweepGeneration*)_old_gen, 736 _rem_set->as_CardTableRS(), 737 (ConcurrentMarkSweepPolicy*) collector_policy()); 738 739 if (collector == NULL || !collector->completed_initialization()) { 740 if (collector) { 741 delete collector; // Be nice in embedded situation 742 } 743 vm_shutdown_during_initialization("Could not create CMS collector"); 744 return false; 745 } 746 return true; // success 747 } 748 749 void GenCollectedHeap::collect_mostly_concurrent(GCCause::Cause cause) { 750 assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock"); 751 752 MutexLocker ml(Heap_lock); 753 // Read the GC counts while holding the Heap_lock 754 unsigned int full_gc_count_before = total_full_collections(); 755 unsigned int gc_count_before = total_collections(); 756 { 757 MutexUnlocker mu(Heap_lock); 758 VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause); 759 VMThread::execute(&op); 760 } 761 } 762 #endif // INCLUDE_ALL_GCS 763 764 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs) { 765 do_full_collection(clear_all_soft_refs, _n_gens - 1); 766 } 767 768 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs, 769 int max_level) { 770 int local_max_level; 771 if (!incremental_collection_will_fail(false /* don't consult_young */) && 772 gc_cause() == GCCause::_gc_locker) { 773 local_max_level = 0; 774 } else { 775 local_max_level = max_level; 776 } 777 778 do_collection(true /* full */, 779 clear_all_soft_refs /* clear_all_soft_refs */, 780 0 /* size */, 781 false /* is_tlab */, 782 local_max_level /* max_level */); 783 // Hack XXX FIX ME !!! 784 // A scavenge may not have been attempted, or may have 785 // been attempted and failed, because the old gen was too full 786 if (local_max_level == 0 && gc_cause() == GCCause::_gc_locker && 787 incremental_collection_will_fail(false /* don't consult_young */)) { 788 if (PrintGCDetails) { 789 gclog_or_tty->print_cr("GC locker: Trying a full collection " 790 "because scavenge failed"); 791 } 792 // This time allow the old gen to be collected as well 793 do_collection(true /* full */, 794 clear_all_soft_refs /* clear_all_soft_refs */, 795 0 /* size */, 796 false /* is_tlab */, 797 n_gens() - 1 /* max_level */); 798 } 799 } 800 801 bool GenCollectedHeap::is_in_young(oop p) { 802 bool result = ((HeapWord*)p) < _old_gen->reserved().start(); 803 assert(result == _young_gen->is_in_reserved(p), 804 err_msg("incorrect test - result=%d, p=" INTPTR_FORMAT, result, p2i((void*)p))); 805 return result; 806 } 807 808 // Returns "TRUE" iff "p" points into the committed areas of the heap. 809 bool GenCollectedHeap::is_in(const void* p) const { 810 #ifndef ASSERT 811 guarantee(VerifyBeforeGC || 812 VerifyDuringGC || 813 VerifyBeforeExit || 814 VerifyDuringStartup || 815 PrintAssembly || 816 tty->count() != 0 || // already printing 817 VerifyAfterGC || 818 VMError::fatal_error_in_progress(), "too expensive"); 819 820 #endif 821 // This might be sped up with a cache of the last generation that 822 // answered yes. 823 if (_young_gen->is_in(p) || _old_gen->is_in(p)) { 824 return true; 825 } 826 // Otherwise... 827 return false; 828 } 829 830 #ifdef ASSERT 831 // Don't implement this by using is_in_young(). This method is used 832 // in some cases to check that is_in_young() is correct. 833 bool GenCollectedHeap::is_in_partial_collection(const void* p) { 834 assert(is_in_reserved(p) || p == NULL, 835 "Does not work if address is non-null and outside of the heap"); 836 return p < _young_gen->reserved().end() && p != NULL; 837 } 838 #endif 839 840 void GenCollectedHeap::oop_iterate(ExtendedOopClosure* cl) { 841 _young_gen->oop_iterate(cl); 842 _old_gen->oop_iterate(cl); 843 } 844 845 void GenCollectedHeap::object_iterate(ObjectClosure* cl) { 846 _young_gen->object_iterate(cl); 847 _old_gen->object_iterate(cl); 848 } 849 850 void GenCollectedHeap::safe_object_iterate(ObjectClosure* cl) { 851 _young_gen->safe_object_iterate(cl); 852 _old_gen->safe_object_iterate(cl); 853 } 854 855 Space* GenCollectedHeap::space_containing(const void* addr) const { 856 Space* res = _young_gen->space_containing(addr); 857 if (res != NULL) { 858 return res; 859 } 860 res = _old_gen->space_containing(addr); 861 assert(res != NULL, "Could not find containing space"); 862 return res; 863 } 864 865 HeapWord* GenCollectedHeap::block_start(const void* addr) const { 866 assert(is_in_reserved(addr), "block_start of address outside of heap"); 867 if (_young_gen->is_in_reserved(addr)) { 868 assert(_young_gen->is_in(addr), "addr should be in allocated part of generation"); 869 return _young_gen->block_start(addr); 870 } 871 872 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address"); 873 assert(_old_gen->is_in(addr), "addr should be in allocated part of generation"); 874 return _old_gen->block_start(addr); 875 } 876 877 size_t GenCollectedHeap::block_size(const HeapWord* addr) const { 878 assert(is_in_reserved(addr), "block_size of address outside of heap"); 879 if (_young_gen->is_in_reserved(addr)) { 880 assert(_young_gen->is_in(addr), "addr should be in allocated part of generation"); 881 return _young_gen->block_size(addr); 882 } 883 884 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address"); 885 assert(_old_gen->is_in(addr), "addr should be in allocated part of generation"); 886 return _old_gen->block_size(addr); 887 } 888 889 bool GenCollectedHeap::block_is_obj(const HeapWord* addr) const { 890 assert(is_in_reserved(addr), "block_is_obj of address outside of heap"); 891 assert(block_start(addr) == addr, "addr must be a block start"); 892 if (_young_gen->is_in_reserved(addr)) { 893 return _young_gen->block_is_obj(addr); 894 } 895 896 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address"); 897 return _old_gen->block_is_obj(addr); 898 } 899 900 bool GenCollectedHeap::supports_tlab_allocation() const { 901 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!"); 902 return _young_gen->supports_tlab_allocation(); 903 } 904 905 size_t GenCollectedHeap::tlab_capacity(Thread* thr) const { 906 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!"); 907 if (_young_gen->supports_tlab_allocation()) { 908 return _young_gen->tlab_capacity(); 909 } 910 return 0; 911 } 912 913 size_t GenCollectedHeap::tlab_used(Thread* thr) const { 914 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!"); 915 if (_young_gen->supports_tlab_allocation()) { 916 return _young_gen->tlab_used(); 917 } 918 return 0; 919 } 920 921 size_t GenCollectedHeap::unsafe_max_tlab_alloc(Thread* thr) const { 922 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!"); 923 if (_young_gen->supports_tlab_allocation()) { 924 return _young_gen->unsafe_max_tlab_alloc(); 925 } 926 return 0; 927 } 928 929 HeapWord* GenCollectedHeap::allocate_new_tlab(size_t size) { 930 bool gc_overhead_limit_was_exceeded; 931 return collector_policy()->mem_allocate_work(size /* size */, 932 true /* is_tlab */, 933 &gc_overhead_limit_was_exceeded); 934 } 935 936 // Requires "*prev_ptr" to be non-NULL. Deletes and a block of minimal size 937 // from the list headed by "*prev_ptr". 938 static ScratchBlock *removeSmallestScratch(ScratchBlock **prev_ptr) { 939 bool first = true; 940 size_t min_size = 0; // "first" makes this conceptually infinite. 941 ScratchBlock **smallest_ptr, *smallest; 942 ScratchBlock *cur = *prev_ptr; 943 while (cur) { 944 assert(*prev_ptr == cur, "just checking"); 945 if (first || cur->num_words < min_size) { 946 smallest_ptr = prev_ptr; 947 smallest = cur; 948 min_size = smallest->num_words; 949 first = false; 950 } 951 prev_ptr = &cur->next; 952 cur = cur->next; 953 } 954 smallest = *smallest_ptr; 955 *smallest_ptr = smallest->next; 956 return smallest; 957 } 958 959 // Sort the scratch block list headed by res into decreasing size order, 960 // and set "res" to the result. 961 static void sort_scratch_list(ScratchBlock*& list) { 962 ScratchBlock* sorted = NULL; 963 ScratchBlock* unsorted = list; 964 while (unsorted) { 965 ScratchBlock *smallest = removeSmallestScratch(&unsorted); 966 smallest->next = sorted; 967 sorted = smallest; 968 } 969 list = sorted; 970 } 971 972 ScratchBlock* GenCollectedHeap::gather_scratch(Generation* requestor, 973 size_t max_alloc_words) { 974 ScratchBlock* res = NULL; 975 _young_gen->contribute_scratch(res, requestor, max_alloc_words); 976 _old_gen->contribute_scratch(res, requestor, max_alloc_words); 977 sort_scratch_list(res); 978 return res; 979 } 980 981 void GenCollectedHeap::release_scratch() { 982 _young_gen->reset_scratch(); 983 _old_gen->reset_scratch(); 984 } 985 986 class GenPrepareForVerifyClosure: public GenCollectedHeap::GenClosure { 987 void do_generation(Generation* gen) { 988 gen->prepare_for_verify(); 989 } 990 }; 991 992 void GenCollectedHeap::prepare_for_verify() { 993 ensure_parsability(false); // no need to retire TLABs 994 GenPrepareForVerifyClosure blk; 995 generation_iterate(&blk, false); 996 } 997 998 void GenCollectedHeap::generation_iterate(GenClosure* cl, 999 bool old_to_young) { 1000 if (old_to_young) { 1001 cl->do_generation(_old_gen); 1002 cl->do_generation(_young_gen); 1003 } else { 1004 cl->do_generation(_young_gen); 1005 cl->do_generation(_old_gen); 1006 } 1007 } 1008 1009 void GenCollectedHeap::space_iterate(SpaceClosure* cl) { 1010 _young_gen->space_iterate(cl, true); 1011 _old_gen->space_iterate(cl, true); 1012 } 1013 1014 bool GenCollectedHeap::is_maximal_no_gc() const { 1015 return _young_gen->is_maximal_no_gc() && _old_gen->is_maximal_no_gc(); 1016 } 1017 1018 void GenCollectedHeap::save_marks() { 1019 _young_gen->save_marks(); 1020 _old_gen->save_marks(); 1021 } 1022 1023 GenCollectedHeap* GenCollectedHeap::heap() { 1024 assert(_gch != NULL, "Uninitialized access to GenCollectedHeap::heap()"); 1025 assert(_gch->kind() == CollectedHeap::GenCollectedHeap, "not a generational heap"); 1026 return _gch; 1027 } 1028 1029 1030 void GenCollectedHeap::prepare_for_compaction() { 1031 guarantee(_n_gens = 2, "Wrong number of generations"); 1032 // Start by compacting into same gen. 1033 CompactPoint cp(_old_gen); 1034 _old_gen->prepare_for_compaction(&cp); 1035 _young_gen->prepare_for_compaction(&cp); 1036 } 1037 1038 void GenCollectedHeap::verify(bool silent, VerifyOption option /* ignored */) { 1039 if (!silent) { 1040 gclog_or_tty->print("%s", _old_gen->name()); 1041 gclog_or_tty->print(" "); 1042 } 1043 _old_gen->verify(); 1044 1045 if (!silent) { 1046 gclog_or_tty->print("%s", _young_gen->name()); 1047 gclog_or_tty->print(" "); 1048 } 1049 _young_gen->verify(); 1050 1051 if (!silent) { 1052 gclog_or_tty->print("remset "); 1053 } 1054 rem_set()->verify(); 1055 } 1056 1057 void GenCollectedHeap::print_on(outputStream* st) const { 1058 _young_gen->print_on(st); 1059 _old_gen->print_on(st); 1060 MetaspaceAux::print_on(st); 1061 } 1062 1063 void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const { 1064 if (workers() != NULL) { 1065 workers()->threads_do(tc); 1066 } 1067 #if INCLUDE_ALL_GCS 1068 if (UseConcMarkSweepGC) { 1069 ConcurrentMarkSweepThread::threads_do(tc); 1070 } 1071 #endif // INCLUDE_ALL_GCS 1072 } 1073 1074 void GenCollectedHeap::print_gc_threads_on(outputStream* st) const { 1075 #if INCLUDE_ALL_GCS 1076 if (UseParNewGC) { 1077 workers()->print_worker_threads_on(st); 1078 } 1079 if (UseConcMarkSweepGC) { 1080 ConcurrentMarkSweepThread::print_all_on(st); 1081 } 1082 #endif // INCLUDE_ALL_GCS 1083 } 1084 1085 void GenCollectedHeap::print_on_error(outputStream* st) const { 1086 this->CollectedHeap::print_on_error(st); 1087 1088 #if INCLUDE_ALL_GCS 1089 if (UseConcMarkSweepGC) { 1090 st->cr(); 1091 CMSCollector::print_on_error(st); 1092 } 1093 #endif // INCLUDE_ALL_GCS 1094 } 1095 1096 void GenCollectedHeap::print_tracing_info() const { 1097 if (TraceYoungGenTime) { 1098 _young_gen->print_summary_info(); 1099 } 1100 if (TraceOldGenTime) { 1101 _old_gen->print_summary_info(); 1102 } 1103 } 1104 1105 void GenCollectedHeap::print_heap_change(size_t prev_used) const { 1106 if (PrintGCDetails && Verbose) { 1107 gclog_or_tty->print(" " SIZE_FORMAT 1108 "->" SIZE_FORMAT 1109 "(" SIZE_FORMAT ")", 1110 prev_used, used(), capacity()); 1111 } else { 1112 gclog_or_tty->print(" " SIZE_FORMAT "K" 1113 "->" SIZE_FORMAT "K" 1114 "(" SIZE_FORMAT "K)", 1115 prev_used / K, used() / K, capacity() / K); 1116 } 1117 } 1118 1119 class GenGCPrologueClosure: public GenCollectedHeap::GenClosure { 1120 private: 1121 bool _full; 1122 public: 1123 void do_generation(Generation* gen) { 1124 gen->gc_prologue(_full); 1125 } 1126 GenGCPrologueClosure(bool full) : _full(full) {}; 1127 }; 1128 1129 void GenCollectedHeap::gc_prologue(bool full) { 1130 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer"); 1131 1132 always_do_update_barrier = false; 1133 // Fill TLAB's and such 1134 CollectedHeap::accumulate_statistics_all_tlabs(); 1135 ensure_parsability(true); // retire TLABs 1136 1137 // Walk generations 1138 GenGCPrologueClosure blk(full); 1139 generation_iterate(&blk, false); // not old-to-young. 1140 }; 1141 1142 class GenGCEpilogueClosure: public GenCollectedHeap::GenClosure { 1143 private: 1144 bool _full; 1145 public: 1146 void do_generation(Generation* gen) { 1147 gen->gc_epilogue(_full); 1148 } 1149 GenGCEpilogueClosure(bool full) : _full(full) {}; 1150 }; 1151 1152 void GenCollectedHeap::gc_epilogue(bool full) { 1153 #ifdef COMPILER2 1154 assert(DerivedPointerTable::is_empty(), "derived pointer present"); 1155 size_t actual_gap = pointer_delta((HeapWord*) (max_uintx-3), *(end_addr())); 1156 guarantee(actual_gap > (size_t)FastAllocateSizeLimit, "inline allocation wraps"); 1157 #endif /* COMPILER2 */ 1158 1159 resize_all_tlabs(); 1160 1161 GenGCEpilogueClosure blk(full); 1162 generation_iterate(&blk, false); // not old-to-young. 1163 1164 if (!CleanChunkPoolAsync) { 1165 Chunk::clean_chunk_pool(); 1166 } 1167 1168 MetaspaceCounters::update_performance_counters(); 1169 CompressedClassSpaceCounters::update_performance_counters(); 1170 1171 always_do_update_barrier = UseConcMarkSweepGC; 1172 }; 1173 1174 #ifndef PRODUCT 1175 class GenGCSaveTopsBeforeGCClosure: public GenCollectedHeap::GenClosure { 1176 private: 1177 public: 1178 void do_generation(Generation* gen) { 1179 gen->record_spaces_top(); 1180 } 1181 }; 1182 1183 void GenCollectedHeap::record_gen_tops_before_GC() { 1184 if (ZapUnusedHeapArea) { 1185 GenGCSaveTopsBeforeGCClosure blk; 1186 generation_iterate(&blk, false); // not old-to-young. 1187 } 1188 } 1189 #endif // not PRODUCT 1190 1191 class GenEnsureParsabilityClosure: public GenCollectedHeap::GenClosure { 1192 public: 1193 void do_generation(Generation* gen) { 1194 gen->ensure_parsability(); 1195 } 1196 }; 1197 1198 void GenCollectedHeap::ensure_parsability(bool retire_tlabs) { 1199 CollectedHeap::ensure_parsability(retire_tlabs); 1200 GenEnsureParsabilityClosure ep_cl; 1201 generation_iterate(&ep_cl, false); 1202 } 1203 1204 oop GenCollectedHeap::handle_failed_promotion(Generation* old_gen, 1205 oop obj, 1206 size_t obj_size) { 1207 guarantee(old_gen->level() == 1, "We only get here with an old generation"); 1208 assert(obj_size == (size_t)obj->size(), "bad obj_size passed in"); 1209 HeapWord* result = NULL; 1210 1211 result = old_gen->expand_and_allocate(obj_size, false); 1212 1213 if (result != NULL) { 1214 Copy::aligned_disjoint_words((HeapWord*)obj, result, obj_size); 1215 } 1216 return oop(result); 1217 } 1218 1219 class GenTimeOfLastGCClosure: public GenCollectedHeap::GenClosure { 1220 jlong _time; // in ms 1221 jlong _now; // in ms 1222 1223 public: 1224 GenTimeOfLastGCClosure(jlong now) : _time(now), _now(now) { } 1225 1226 jlong time() { return _time; } 1227 1228 void do_generation(Generation* gen) { 1229 _time = MIN2(_time, gen->time_of_last_gc(_now)); 1230 } 1231 }; 1232 1233 jlong GenCollectedHeap::millis_since_last_gc() { 1234 // We need a monotonically non-decreasing time in ms but 1235 // os::javaTimeMillis() does not guarantee monotonicity. 1236 jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC; 1237 GenTimeOfLastGCClosure tolgc_cl(now); 1238 // iterate over generations getting the oldest 1239 // time that a generation was collected 1240 generation_iterate(&tolgc_cl, false); 1241 1242 // javaTimeNanos() is guaranteed to be monotonically non-decreasing 1243 // provided the underlying platform provides such a time source 1244 // (and it is bug free). So we still have to guard against getting 1245 // back a time later than 'now'. 1246 jlong retVal = now - tolgc_cl.time(); 1247 if (retVal < 0) { 1248 NOT_PRODUCT(warning("time warp: "INT64_FORMAT, (int64_t) retVal);) 1249 return 0; 1250 } 1251 return retVal; 1252 }