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/generationSpec.hpp"
40 #include "memory/resourceArea.hpp"
41 #include "memory/sharedHeap.hpp"
42 #include "memory/space.hpp"
43 #include "oops/oop.inline.hpp"
44 #include "oops/oop.inline2.hpp"
45 #include "runtime/biasedLocking.hpp"
46 #include "runtime/fprofiler.hpp"
47 #include "runtime/handles.hpp"
48 #include "runtime/handles.inline.hpp"
49 #include "runtime/java.hpp"
50 #include "runtime/vmThread.hpp"
51 #include "services/memoryService.hpp"
52 #include "utilities/vmError.hpp"
53 #include "utilities/workgroup.hpp"
54 #include "utilities/macros.hpp"
55 #if INCLUDE_ALL_GCS
56 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp"
57 #include "gc_implementation/concurrentMarkSweep/vmCMSOperations.hpp"
58 #endif // INCLUDE_ALL_GCS
59
60 GenCollectedHeap* GenCollectedHeap::_gch;
61 NOT_PRODUCT(size_t GenCollectedHeap::_skip_header_HeapWords = 0;)
62
63 // The set of potentially parallel tasks in root scanning.
64 enum GCH_strong_roots_tasks {
65 // We probably want to parallelize both of these internally, but for now...
66 GCH_PS_younger_gens,
67 // Leave this one last.
68 GCH_PS_NumElements
69 };
70
71 GenCollectedHeap::GenCollectedHeap(GenCollectorPolicy *policy) :
72 SharedHeap(policy),
73 _rem_set(NULL),
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 // The heap must be at least as aligned as generations.
99 size_t gen_alignment = Generation::GenGrain;
100
101 _gen_specs = gen_policy()->generations();
102
103 // Make sure the sizes are all aligned.
104 for (i = 0; i < _n_gens; i++) {
105 _gen_specs[i]->align(gen_alignment);
106 }
107
108 // Allocate space for the heap.
109
110 char* heap_address;
111 size_t total_reserved = 0;
112 ReservedSpace heap_rs;
113
114 size_t heap_alignment = collector_policy()->heap_alignment();
115
116 heap_address = allocate(heap_alignment, &total_reserved, &heap_rs);
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((HeapWord*)heap_rs.base(), (HeapWord*)(heap_rs.base() + heap_rs.size()));
125
126 _rem_set = collector_policy()->create_rem_set(reserved_region());
127 set_barrier_set(rem_set()->bs());
128
129 _gch = this;
130
131 ReservedSpace young_rs = heap_rs.first_part(_gen_specs[0]->max_size(), false, false);
132 _young_gen = _gen_specs[0]->init(young_rs, 0, rem_set());
133 heap_rs = heap_rs.last_part(_gen_specs[0]->max_size());
134
135 ReservedSpace old_rs = heap_rs.first_part(_gen_specs[1]->max_size(), false, false);
136 _old_gen = _gen_specs[1]->init(old_rs, 1, rem_set());
137 heap_rs = heap_rs.last_part(_gen_specs[1]->max_size());
138 clear_incremental_collection_failed();
139
140 #if INCLUDE_ALL_GCS
141 // If we are running CMS, create the collector responsible
142 // for collecting the CMS generations.
143 if (collector_policy()->is_concurrent_mark_sweep_policy()) {
144 bool success = create_cms_collector();
145 if (!success) return JNI_ENOMEM;
146 }
147 #endif // INCLUDE_ALL_GCS
148
149 return JNI_OK;
150 }
151
152 char* GenCollectedHeap::allocate(size_t alignment,
153 size_t* _total_reserved,
154 ReservedSpace* heap_rs){
155 const char overflow_msg[] = "The size of the object heap + VM data exceeds "
156 "the maximum representable size";
157
158 // Now figure out the total size.
159 size_t total_reserved = 0;
160 const size_t pageSize = UseLargePages ?
161 os::large_page_size() : os::vm_page_size();
162
163 assert(alignment % pageSize == 0, "Must be");
164
165 for (int i = 0; i < _n_gens; i++) {
166 total_reserved += _gen_specs[i]->max_size();
167 if (total_reserved < _gen_specs[i]->max_size()) {
168 vm_exit_during_initialization(overflow_msg);
169 }
170 }
171 assert(total_reserved % alignment == 0,
172 err_msg("Gen size; total_reserved=" SIZE_FORMAT ", alignment="
173 SIZE_FORMAT, total_reserved, alignment));
174
175 *_total_reserved = total_reserved;
176
177 *heap_rs = Universe::reserve_heap(total_reserved, alignment);
178 return heap_rs->base();
179 }
180
181 void GenCollectedHeap::post_initialize() {
182 SharedHeap::post_initialize();
183 GenCollectorPolicy *policy = (GenCollectorPolicy *)collector_policy();
184 guarantee(policy->is_generation_policy(), "Illegal policy type");
185 assert((get_gen(0)->kind() == Generation::DefNew) ||
186 (get_gen(0)->kind() == Generation::ParNew),
187 "Wrong youngest generation type");
188 DefNewGeneration* def_new_gen = (DefNewGeneration*)get_gen(0);
189
190 Generation* old_gen = get_gen(1);
191 assert(old_gen->kind() == Generation::ConcurrentMarkSweep ||
192 old_gen->kind() == Generation::MarkSweepCompact,
193 "Wrong generation kind");
194
195 policy->initialize_size_policy(def_new_gen->eden()->capacity(),
196 old_gen->capacity(),
197 def_new_gen->from()->capacity());
198 policy->initialize_gc_policy_counters();
199 }
200
201 void GenCollectedHeap::ref_processing_init() {
202 SharedHeap::ref_processing_init();
203 _young_gen->ref_processor_init();
204 _old_gen->ref_processor_init();
205 }
206
207 size_t GenCollectedHeap::capacity() const {
208 return _young_gen->capacity() + _old_gen->capacity();
209 }
210
211 size_t GenCollectedHeap::used() const {
212 return _young_gen->used() + _old_gen->used();
213 }
214
215 // Save the "used_region" for generations level and lower.
216 void GenCollectedHeap::save_used_regions(int level) {
217 assert(level < _n_gens, "Illegal level parameter");
218 if (level == 1) {
219 _old_gen->save_used_region();
220 }
221 _young_gen->save_used_region();
222 }
223
224 size_t GenCollectedHeap::max_capacity() const {
225 return _young_gen->max_capacity() + _old_gen->max_capacity();
226 }
227
228 // Update the _full_collections_completed counter
229 // at the end of a stop-world full GC.
230 unsigned int GenCollectedHeap::update_full_collections_completed() {
231 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
232 assert(_full_collections_completed <= _total_full_collections,
233 "Can't complete more collections than were started");
234 _full_collections_completed = _total_full_collections;
235 ml.notify_all();
236 return _full_collections_completed;
237 }
238
239 // Update the _full_collections_completed counter, as appropriate,
240 // at the end of a concurrent GC cycle. Note the conditional update
241 // below to allow this method to be called by a concurrent collector
242 // without synchronizing in any manner with the VM thread (which
243 // may already have initiated a STW full collection "concurrently").
244 unsigned int GenCollectedHeap::update_full_collections_completed(unsigned int count) {
245 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
246 assert((_full_collections_completed <= _total_full_collections) &&
247 (count <= _total_full_collections),
248 "Can't complete more collections than were started");
249 if (count > _full_collections_completed) {
250 _full_collections_completed = count;
251 ml.notify_all();
252 }
253 return _full_collections_completed;
254 }
255
256
257 #ifndef PRODUCT
258 // Override of memory state checking method in CollectedHeap:
259 // Some collectors (CMS for example) can't have badHeapWordVal written
260 // in the first two words of an object. (For instance , in the case of
261 // CMS these words hold state used to synchronize between certain
262 // (concurrent) GC steps and direct allocating mutators.)
263 // The skip_header_HeapWords() method below, allows us to skip
264 // over the requisite number of HeapWord's. Note that (for
265 // generational collectors) this means that those many words are
266 // skipped in each object, irrespective of the generation in which
267 // that object lives. The resultant loss of precision seems to be
268 // harmless and the pain of avoiding that imprecision appears somewhat
269 // higher than we are prepared to pay for such rudimentary debugging
270 // support.
271 void GenCollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr,
272 size_t size) {
273 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
274 // We are asked to check a size in HeapWords,
275 // but the memory is mangled in juint words.
276 juint* start = (juint*) (addr + skip_header_HeapWords());
277 juint* end = (juint*) (addr + size);
278 for (juint* slot = start; slot < end; slot += 1) {
279 assert(*slot == badHeapWordVal,
280 "Found non badHeapWordValue in pre-allocation check");
281 }
282 }
283 }
284 #endif
285
286 HeapWord* GenCollectedHeap::attempt_allocation(size_t size,
287 bool is_tlab,
288 bool first_only) {
289 HeapWord* res = NULL;
290
291 if (_young_gen->should_allocate(size, is_tlab)) {
292 res = _young_gen->allocate(size, is_tlab);
293 if (res != NULL || first_only) {
294 return res;
295 }
296 }
297
298 if (_old_gen->should_allocate(size, is_tlab)) {
299 res = _old_gen->allocate(size, is_tlab);
300 }
301
302 return res;
303 }
304
305 HeapWord* GenCollectedHeap::mem_allocate(size_t size,
306 bool* gc_overhead_limit_was_exceeded) {
307 return collector_policy()->mem_allocate_work(size,
308 false /* is_tlab */,
309 gc_overhead_limit_was_exceeded);
310 }
311
312 bool GenCollectedHeap::must_clear_all_soft_refs() {
313 return _gc_cause == GCCause::_last_ditch_collection;
314 }
315
316 bool GenCollectedHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
317 return UseConcMarkSweepGC &&
318 ((cause == GCCause::_gc_locker && GCLockerInvokesConcurrent) ||
319 (cause == GCCause::_java_lang_system_gc && ExplicitGCInvokesConcurrent));
320 }
321
322 void GenCollectedHeap::collect_generation(Generation* gen, bool full, size_t size,
323 bool is_tlab, bool run_verification, bool clear_soft_refs,
324 bool restore_marks_for_biased_locking) {
325 // Timer for individual generations. Last argument is false: no CR
326 // FIXME: We should try to start the timing earlier to cover more of the GC pause
327 // The PrintGCDetails logging starts before we have incremented the GC id. We will do that later
328 // so we can assume here that the next GC id is what we want.
329 GCTraceTime t1(gen->short_name(), PrintGCDetails, false, NULL, GCId::peek());
330 TraceCollectorStats tcs(gen->counters());
331 TraceMemoryManagerStats tmms(gen->kind(),gc_cause());
332
333 size_t prev_used = gen->used();
334 gen->stat_record()->invocations++;
335 gen->stat_record()->accumulated_time.start();
336
337 // Must be done anew before each collection because
338 // a previous collection will do mangling and will
339 // change top of some spaces.
340 record_gen_tops_before_GC();
341
342 if (PrintGC && Verbose) {
343 gclog_or_tty->print("level=%d invoke=%d size=" SIZE_FORMAT,
344 gen->level(),
345 gen->stat_record()->invocations,
346 size * HeapWordSize);
347 }
348
349 if (run_verification && VerifyBeforeGC) {
350 HandleMark hm; // Discard invalid handles created during verification
351 Universe::verify(" VerifyBeforeGC:");
352 }
353 COMPILER2_PRESENT(DerivedPointerTable::clear());
354
355 if (restore_marks_for_biased_locking) {
356 // We perform this mark word preservation work lazily
357 // because it's only at this point that we know whether we
358 // absolutely have to do it; we want to avoid doing it for
359 // scavenge-only collections where it's unnecessary
360 BiasedLocking::preserve_marks();
361 }
362
363 // Do collection work
364 {
365 // Note on ref discovery: For what appear to be historical reasons,
366 // GCH enables and disabled (by enqueing) refs discovery.
367 // In the future this should be moved into the generation's
368 // collect method so that ref discovery and enqueueing concerns
369 // are local to a generation. The collect method could return
370 // an appropriate indication in the case that notification on
371 // the ref lock was needed. This will make the treatment of
372 // weak refs more uniform (and indeed remove such concerns
373 // from GCH). XXX
374
375 HandleMark hm; // Discard invalid handles created during gc
376 save_marks(); // save marks for all gens
377 // We want to discover references, but not process them yet.
378 // This mode is disabled in process_discovered_references if the
379 // generation does some collection work, or in
380 // enqueue_discovered_references if the generation returns
381 // without doing any work.
382 ReferenceProcessor* rp = gen->ref_processor();
383 // If the discovery of ("weak") refs in this generation is
384 // atomic wrt other collectors in this configuration, we
385 // are guaranteed to have empty discovered ref lists.
386 if (rp->discovery_is_atomic()) {
387 rp->enable_discovery();
388 rp->setup_policy(clear_soft_refs);
389 } else {
390 // collect() below will enable discovery as appropriate
391 }
392 gen->collect(full, clear_soft_refs, size, is_tlab);
393 if (!rp->enqueuing_is_done()) {
394 rp->enqueue_discovered_references();
395 } else {
396 rp->set_enqueuing_is_done(false);
397 }
398 rp->verify_no_references_recorded();
399 }
400
401 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
402
403 gen->stat_record()->accumulated_time.stop();
404
405 update_gc_stats(gen->level(), full);
406
407 if (run_verification && VerifyAfterGC) {
408 HandleMark hm; // Discard invalid handles created during verification
409 Universe::verify(" VerifyAfterGC:");
410 }
411
412 if (PrintGCDetails) {
413 gclog_or_tty->print(":");
414 gen->print_heap_change(prev_used);
415 }
416 }
417
418 void GenCollectedHeap::do_collection(bool full,
419 bool clear_all_soft_refs,
420 size_t size,
421 bool is_tlab,
422 int max_level) {
423 ResourceMark rm;
424 DEBUG_ONLY(Thread* my_thread = Thread::current();)
425
426 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
427 assert(my_thread->is_VM_thread() ||
428 my_thread->is_ConcurrentGC_thread(),
429 "incorrect thread type capability");
430 assert(Heap_lock->is_locked(),
431 "the requesting thread should have the Heap_lock");
432 guarantee(!is_gc_active(), "collection is not reentrant");
433 assert(max_level < n_gens(), "sanity check");
434
435 if (GC_locker::check_active_before_gc()) {
436 return; // GC is disabled (e.g. JNI GetXXXCritical operation)
437 }
438
439 const bool do_clear_all_soft_refs = clear_all_soft_refs ||
440 collector_policy()->should_clear_all_soft_refs();
441
442 ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
443
444 const size_t metadata_prev_used = MetaspaceAux::used_bytes();
445
446 print_heap_before_gc();
447
448 {
449 FlagSetting fl(_is_gc_active, true);
450
451 bool complete = full && (max_level == (n_gens()-1));
452 const char* gc_cause_prefix = complete ? "Full GC" : "GC";
453 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
454 // The PrintGCDetails logging starts before we have incremented the GC id. We will do that later
455 // so we can assume here that the next GC id is what we want.
456 GCTraceTime t(GCCauseString(gc_cause_prefix, gc_cause()), PrintGCDetails, false, NULL, GCId::peek());
457
458 gc_prologue(complete);
459 increment_total_collections(complete);
460
461 size_t gch_prev_used = used();
462 bool must_restore_marks_for_biased_locking = false;
463 bool run_verification = total_collections() >= VerifyGCStartAt;
464
465 bool prepared_for_verification = false;
466 int max_level_collected = 0;
467 if (!(max_level == 1 && full && _old_gen->full_collects_younger_generations()) &&
468 _young_gen->should_collect(full, size, is_tlab)) {
469 if (run_verification && VerifyGCLevel <= 0 && VerifyBeforeGC) {
470 prepare_for_verify();
471 prepared_for_verification = true;
472 }
473 if (_young_gen->performs_in_place_marking()) {
474 must_restore_marks_for_biased_locking = true;
475 }
476 collect_generation(_young_gen,
477 full,
478 size,
479 is_tlab,
480 run_verification && VerifyGCLevel <= 0,
481 do_clear_all_soft_refs,
482 must_restore_marks_for_biased_locking);
483
484 if (size > 0 && (!is_tlab || _young_gen->supports_tlab_allocation()) &&
485 size * HeapWordSize <= _young_gen->unsafe_max_alloc_nogc()) {
486 // Allocation request was met by young GC.
487 size = 0;
488 }
489 }
490
491 if (max_level == 1 && _old_gen->should_collect(full, size, is_tlab)) {
492 if (!complete) {
493 // The full_collections increment was missed above.
494 increment_total_full_collections();
495 }
496 pre_full_gc_dump(NULL); // do any pre full gc dumps
497 if (!prepared_for_verification && run_verification &&
498 VerifyGCLevel <= 1 && VerifyBeforeGC) {
499 prepare_for_verify();
500 }
501 assert(_old_gen->performs_in_place_marking(), "All old generations do in place marking");
502 collect_generation(_old_gen,
503 full,
504 size,
505 is_tlab,
506 run_verification && VerifyGCLevel <= 1,
507 do_clear_all_soft_refs,
508 !must_restore_marks_for_biased_locking);
509
510 must_restore_marks_for_biased_locking = true;
511 max_level_collected = 1;
512 }
513
514 // Update "complete" boolean wrt what actually transpired --
515 // for instance, a promotion failure could have led to
516 // a whole heap collection.
517 complete = complete || (max_level_collected == n_gens() - 1);
518
519 if (complete) { // We did a "major" collection
520 // FIXME: See comment at pre_full_gc_dump call
521 post_full_gc_dump(NULL); // do any post full gc dumps
522 }
523
524 if (PrintGCDetails) {
525 print_heap_change(gch_prev_used);
526
527 // Print metaspace info for full GC with PrintGCDetails flag.
528 if (complete) {
529 MetaspaceAux::print_metaspace_change(metadata_prev_used);
530 }
531 }
532
533 // Adjust generation sizes.
534 if (max_level_collected == 1) {
535 _old_gen->compute_new_size();
536 }
537 _young_gen->compute_new_size();
538
539 if (complete) {
540 // Delete metaspaces for unloaded class loaders and clean up loader_data graph
541 ClassLoaderDataGraph::purge();
542 MetaspaceAux::verify_metrics();
543 // Resize the metaspace capacity after full collections
544 MetaspaceGC::compute_new_size();
545 update_full_collections_completed();
546 }
547
548 // Track memory usage and detect low memory after GC finishes
549 MemoryService::track_memory_usage();
550
551 gc_epilogue(complete);
552
553 if (must_restore_marks_for_biased_locking) {
554 BiasedLocking::restore_marks();
555 }
556 }
557
558 print_heap_after_gc();
559
560 #ifdef TRACESPINNING
561 ParallelTaskTerminator::print_termination_counts();
562 #endif
563 }
564
565 HeapWord* GenCollectedHeap::satisfy_failed_allocation(size_t size, bool is_tlab) {
566 return collector_policy()->satisfy_failed_allocation(size, is_tlab);
567 }
568
569 void GenCollectedHeap::set_par_threads(uint t) {
570 SharedHeap::set_par_threads(t);
571 _gen_process_roots_tasks->set_n_threads(t);
572 }
573
574 void GenCollectedHeap::
575 gen_process_roots(int level,
576 bool younger_gens_as_roots,
577 bool activate_scope,
578 SharedHeap::ScanningOption so,
579 OopsInGenClosure* not_older_gens,
580 OopsInGenClosure* weak_roots,
581 OopsInGenClosure* older_gens,
582 CLDClosure* cld_closure,
583 CLDClosure* weak_cld_closure,
584 CodeBlobClosure* code_closure) {
585
586 // General roots.
587 SharedHeap::process_roots(activate_scope, so,
588 not_older_gens, weak_roots,
589 cld_closure, weak_cld_closure,
590 code_closure);
591
592 if (younger_gens_as_roots) {
593 if (!_gen_process_roots_tasks->is_task_claimed(GCH_PS_younger_gens)) {
594 if (level == 1) {
595 not_older_gens->set_generation(_young_gen);
596 _young_gen->oop_iterate(not_older_gens);
597 }
598 not_older_gens->reset_generation();
599 }
600 }
601 // When collection is parallel, all threads get to cooperate to do
602 // older-gen scanning.
603 if (level == 0) {
604 older_gens->set_generation(_old_gen);
605 rem_set()->younger_refs_iterate(_old_gen, older_gens);
606 older_gens->reset_generation();
607 }
608
609 _gen_process_roots_tasks->all_tasks_completed();
610 }
611
612 void GenCollectedHeap::
613 gen_process_roots(int level,
614 bool younger_gens_as_roots,
615 bool activate_scope,
616 SharedHeap::ScanningOption so,
617 bool only_strong_roots,
618 OopsInGenClosure* not_older_gens,
619 OopsInGenClosure* older_gens,
620 CLDClosure* cld_closure) {
621
622 const bool is_adjust_phase = !only_strong_roots && !younger_gens_as_roots;
623
624 bool is_moving_collection = false;
625 if (level == 0 || is_adjust_phase) {
626 // young collections are always moving
627 is_moving_collection = true;
628 }
629
630 MarkingCodeBlobClosure mark_code_closure(not_older_gens, is_moving_collection);
631 CodeBlobClosure* code_closure = &mark_code_closure;
632
633 gen_process_roots(level,
634 younger_gens_as_roots,
635 activate_scope, so,
636 not_older_gens, only_strong_roots ? NULL : not_older_gens,
637 older_gens,
638 cld_closure, only_strong_roots ? NULL : cld_closure,
639 code_closure);
640
641 }
642
643 void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure) {
644 SharedHeap::process_weak_roots(root_closure);
645 // "Local" "weak" refs
646 _young_gen->ref_processor()->weak_oops_do(root_closure);
647 _old_gen->ref_processor()->weak_oops_do(root_closure);
648 }
649
650 #define GCH_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix) \
651 void GenCollectedHeap:: \
652 oop_since_save_marks_iterate(int level, \
653 OopClosureType* cur, \
654 OopClosureType* older) { \
655 if (level == 0) { \
656 _young_gen->oop_since_save_marks_iterate##nv_suffix(cur); \
657 _old_gen->oop_since_save_marks_iterate##nv_suffix(older); \
658 } else { \
659 _old_gen->oop_since_save_marks_iterate##nv_suffix(cur); \
660 } \
661 }
662
663 ALL_SINCE_SAVE_MARKS_CLOSURES(GCH_SINCE_SAVE_MARKS_ITERATE_DEFN)
664
665 #undef GCH_SINCE_SAVE_MARKS_ITERATE_DEFN
666
667 bool GenCollectedHeap::no_allocs_since_save_marks(int level) {
668 if (level == 0 && !_young_gen->no_allocs_since_save_marks()) {
669 return false;
670 }
671 return _old_gen->no_allocs_since_save_marks();
672 }
673
674 bool GenCollectedHeap::supports_inline_contig_alloc() const {
675 return _young_gen->supports_inline_contig_alloc();
676 }
677
678 HeapWord** GenCollectedHeap::top_addr() const {
679 return _young_gen->top_addr();
680 }
681
682 HeapWord** GenCollectedHeap::end_addr() const {
683 return _young_gen->end_addr();
684 }
685
686 // public collection interfaces
687
688 void GenCollectedHeap::collect(GCCause::Cause cause) {
689 if (should_do_concurrent_full_gc(cause)) {
690 #if INCLUDE_ALL_GCS
691 // mostly concurrent full collection
692 collect_mostly_concurrent(cause);
693 #else // INCLUDE_ALL_GCS
694 ShouldNotReachHere();
695 #endif // INCLUDE_ALL_GCS
696 } else if (cause == GCCause::_wb_young_gc) {
697 // minor collection for WhiteBox API
698 collect(cause, 0);
699 } else {
700 #ifdef ASSERT
701 if (cause == GCCause::_scavenge_alot) {
702 // minor collection only
703 collect(cause, 0);
704 } else {
705 // Stop-the-world full collection
706 collect(cause, n_gens() - 1);
707 }
708 #else
709 // Stop-the-world full collection
710 collect(cause, n_gens() - 1);
711 #endif
712 }
713 }
714
715 void GenCollectedHeap::collect(GCCause::Cause cause, int max_level) {
716 // The caller doesn't have the Heap_lock
717 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
718 MutexLocker ml(Heap_lock);
719 collect_locked(cause, max_level);
720 }
721
722 void GenCollectedHeap::collect_locked(GCCause::Cause cause) {
723 // The caller has the Heap_lock
724 assert(Heap_lock->owned_by_self(), "this thread should own the Heap_lock");
725 collect_locked(cause, n_gens() - 1);
726 }
727
728 // this is the private collection interface
729 // The Heap_lock is expected to be held on entry.
730
731 void GenCollectedHeap::collect_locked(GCCause::Cause cause, int max_level) {
732 // Read the GC count while holding the Heap_lock
733 unsigned int gc_count_before = total_collections();
734 unsigned int full_gc_count_before = total_full_collections();
735 {
736 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back
737 VM_GenCollectFull op(gc_count_before, full_gc_count_before,
738 cause, max_level);
739 VMThread::execute(&op);
740 }
741 }
742
743 #if INCLUDE_ALL_GCS
744 bool GenCollectedHeap::create_cms_collector() {
745
746 assert(_old_gen->kind() == Generation::ConcurrentMarkSweep,
747 "Unexpected generation kinds");
748 // Skip two header words in the block content verification
749 NOT_PRODUCT(_skip_header_HeapWords = CMSCollector::skip_header_HeapWords();)
750 CMSCollector* collector = new CMSCollector(
751 (ConcurrentMarkSweepGeneration*)_old_gen,
752 _rem_set->as_CardTableRS(),
753 (ConcurrentMarkSweepPolicy*) collector_policy());
754
755 if (collector == NULL || !collector->completed_initialization()) {
756 if (collector) {
757 delete collector; // Be nice in embedded situation
758 }
759 vm_shutdown_during_initialization("Could not create CMS collector");
760 return false;
761 }
762 return true; // success
763 }
764
765 void GenCollectedHeap::collect_mostly_concurrent(GCCause::Cause cause) {
766 assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock");
767
768 MutexLocker ml(Heap_lock);
769 // Read the GC counts while holding the Heap_lock
770 unsigned int full_gc_count_before = total_full_collections();
771 unsigned int gc_count_before = total_collections();
772 {
773 MutexUnlocker mu(Heap_lock);
774 VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause);
775 VMThread::execute(&op);
776 }
777 }
778 #endif // INCLUDE_ALL_GCS
779
780 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs) {
781 do_full_collection(clear_all_soft_refs, _n_gens - 1);
782 }
783
784 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs,
785 int max_level) {
786 int local_max_level;
787 if (!incremental_collection_will_fail(false /* don't consult_young */) &&
788 gc_cause() == GCCause::_gc_locker) {
789 local_max_level = 0;
790 } else {
791 local_max_level = max_level;
792 }
793
794 do_collection(true /* full */,
795 clear_all_soft_refs /* clear_all_soft_refs */,
796 0 /* size */,
797 false /* is_tlab */,
798 local_max_level /* max_level */);
799 // Hack XXX FIX ME !!!
800 // A scavenge may not have been attempted, or may have
801 // been attempted and failed, because the old gen was too full
802 if (local_max_level == 0 && gc_cause() == GCCause::_gc_locker &&
803 incremental_collection_will_fail(false /* don't consult_young */)) {
804 if (PrintGCDetails) {
805 gclog_or_tty->print_cr("GC locker: Trying a full collection "
806 "because scavenge failed");
807 }
808 // This time allow the old gen to be collected as well
809 do_collection(true /* full */,
810 clear_all_soft_refs /* clear_all_soft_refs */,
811 0 /* size */,
812 false /* is_tlab */,
813 n_gens() - 1 /* max_level */);
814 }
815 }
816
817 bool GenCollectedHeap::is_in_young(oop p) {
818 bool result = ((HeapWord*)p) < _old_gen->reserved().start();
819 assert(result == _young_gen->is_in_reserved(p),
820 err_msg("incorrect test - result=%d, p=" INTPTR_FORMAT, result, p2i((void*)p)));
821 return result;
822 }
823
824 // Returns "TRUE" iff "p" points into the committed areas of the heap.
825 bool GenCollectedHeap::is_in(const void* p) const {
826 #ifndef ASSERT
827 guarantee(VerifyBeforeGC ||
828 VerifyDuringGC ||
829 VerifyBeforeExit ||
830 VerifyDuringStartup ||
831 PrintAssembly ||
832 tty->count() != 0 || // already printing
833 VerifyAfterGC ||
834 VMError::fatal_error_in_progress(), "too expensive");
835
836 #endif
837 // This might be sped up with a cache of the last generation that
838 // answered yes.
839 if (_young_gen->is_in(p) || _old_gen->is_in(p)) {
840 return true;
841 }
842 // Otherwise...
843 return false;
844 }
845
846 #ifdef ASSERT
847 // Don't implement this by using is_in_young(). This method is used
848 // in some cases to check that is_in_young() is correct.
849 bool GenCollectedHeap::is_in_partial_collection(const void* p) {
850 assert(is_in_reserved(p) || p == NULL,
851 "Does not work if address is non-null and outside of the heap");
852 return p < _young_gen->reserved().end() && p != NULL;
853 }
854 #endif
855
856 void GenCollectedHeap::oop_iterate(ExtendedOopClosure* cl) {
857 _young_gen->oop_iterate(cl);
858 _old_gen->oop_iterate(cl);
859 }
860
861 void GenCollectedHeap::object_iterate(ObjectClosure* cl) {
862 _young_gen->object_iterate(cl);
863 _old_gen->object_iterate(cl);
864 }
865
866 void GenCollectedHeap::safe_object_iterate(ObjectClosure* cl) {
867 _young_gen->safe_object_iterate(cl);
868 _old_gen->safe_object_iterate(cl);
869 }
870
871 Space* GenCollectedHeap::space_containing(const void* addr) const {
872 Space* res = _young_gen->space_containing(addr);
873 if (res != NULL) {
874 return res;
875 }
876 res = _old_gen->space_containing(addr);
877 assert(res != NULL, "Could not find containing space");
878 return res;
879 }
880
881 HeapWord* GenCollectedHeap::block_start(const void* addr) const {
882 assert(is_in_reserved(addr), "block_start of address outside of heap");
883 if (_young_gen->is_in_reserved(addr)) {
884 assert(_young_gen->is_in(addr), "addr should be in allocated part of generation");
885 return _young_gen->block_start(addr);
886 }
887
888 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address");
889 assert(_old_gen->is_in(addr), "addr should be in allocated part of generation");
890 return _old_gen->block_start(addr);
891 }
892
893 size_t GenCollectedHeap::block_size(const HeapWord* addr) const {
894 assert(is_in_reserved(addr), "block_size of address outside of heap");
895 if (_young_gen->is_in_reserved(addr)) {
896 assert(_young_gen->is_in(addr), "addr should be in allocated part of generation");
897 return _young_gen->block_size(addr);
898 }
899
900 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address");
901 assert(_old_gen->is_in(addr), "addr should be in allocated part of generation");
902 return _old_gen->block_size(addr);
903 }
904
905 bool GenCollectedHeap::block_is_obj(const HeapWord* addr) const {
906 assert(is_in_reserved(addr), "block_is_obj of address outside of heap");
907 assert(block_start(addr) == addr, "addr must be a block start");
908 if (_young_gen->is_in_reserved(addr)) {
909 return _young_gen->block_is_obj(addr);
910 }
911
912 assert(_old_gen->is_in_reserved(addr), "Some generation should contain the address");
913 return _old_gen->block_is_obj(addr);
914 }
915
916 bool GenCollectedHeap::supports_tlab_allocation() const {
917 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!");
918 return _young_gen->supports_tlab_allocation();
919 }
920
921 size_t GenCollectedHeap::tlab_capacity(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->tlab_capacity();
925 }
926 return 0;
927 }
928
929 size_t GenCollectedHeap::tlab_used(Thread* thr) const {
930 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!");
931 if (_young_gen->supports_tlab_allocation()) {
932 return _young_gen->tlab_used();
933 }
934 return 0;
935 }
936
937 size_t GenCollectedHeap::unsafe_max_tlab_alloc(Thread* thr) const {
938 assert(!_old_gen->supports_tlab_allocation(), "Old gen supports TLAB allocation?!");
939 if (_young_gen->supports_tlab_allocation()) {
940 return _young_gen->unsafe_max_tlab_alloc();
941 }
942 return 0;
943 }
944
945 HeapWord* GenCollectedHeap::allocate_new_tlab(size_t size) {
946 bool gc_overhead_limit_was_exceeded;
947 return collector_policy()->mem_allocate_work(size /* size */,
948 true /* is_tlab */,
949 &gc_overhead_limit_was_exceeded);
950 }
951
952 // Requires "*prev_ptr" to be non-NULL. Deletes and a block of minimal size
953 // from the list headed by "*prev_ptr".
954 static ScratchBlock *removeSmallestScratch(ScratchBlock **prev_ptr) {
955 bool first = true;
956 size_t min_size = 0; // "first" makes this conceptually infinite.
957 ScratchBlock **smallest_ptr, *smallest;
958 ScratchBlock *cur = *prev_ptr;
959 while (cur) {
960 assert(*prev_ptr == cur, "just checking");
961 if (first || cur->num_words < min_size) {
962 smallest_ptr = prev_ptr;
963 smallest = cur;
964 min_size = smallest->num_words;
965 first = false;
966 }
967 prev_ptr = &cur->next;
968 cur = cur->next;
969 }
970 smallest = *smallest_ptr;
971 *smallest_ptr = smallest->next;
972 return smallest;
973 }
974
975 // Sort the scratch block list headed by res into decreasing size order,
976 // and set "res" to the result.
977 static void sort_scratch_list(ScratchBlock*& list) {
978 ScratchBlock* sorted = NULL;
979 ScratchBlock* unsorted = list;
980 while (unsorted) {
981 ScratchBlock *smallest = removeSmallestScratch(&unsorted);
982 smallest->next = sorted;
983 sorted = smallest;
984 }
985 list = sorted;
986 }
987
988 ScratchBlock* GenCollectedHeap::gather_scratch(Generation* requestor,
989 size_t max_alloc_words) {
990 ScratchBlock* res = NULL;
991 _young_gen->contribute_scratch(res, requestor, max_alloc_words);
992 _old_gen->contribute_scratch(res, requestor, max_alloc_words);
993 sort_scratch_list(res);
994 return res;
995 }
996
997 void GenCollectedHeap::release_scratch() {
998 _young_gen->reset_scratch();
999 _old_gen->reset_scratch();
1000 }
1001
1002 class GenPrepareForVerifyClosure: public GenCollectedHeap::GenClosure {
1003 void do_generation(Generation* gen) {
1004 gen->prepare_for_verify();
1005 }
1006 };
1007
1008 void GenCollectedHeap::prepare_for_verify() {
1009 ensure_parsability(false); // no need to retire TLABs
1010 GenPrepareForVerifyClosure blk;
1011 generation_iterate(&blk, false);
1012 }
1013
1014 void GenCollectedHeap::generation_iterate(GenClosure* cl,
1015 bool old_to_young) {
1016 if (old_to_young) {
1017 cl->do_generation(_old_gen);
1018 cl->do_generation(_young_gen);
1019 } else {
1020 cl->do_generation(_young_gen);
1021 cl->do_generation(_old_gen);
1022 }
1023 }
1024
1025 void GenCollectedHeap::space_iterate(SpaceClosure* cl) {
1026 _young_gen->space_iterate(cl, true);
1027 _old_gen->space_iterate(cl, true);
1028 }
1029
1030 bool GenCollectedHeap::is_maximal_no_gc() const {
1031 return _young_gen->is_maximal_no_gc() && _old_gen->is_maximal_no_gc();
1032 }
1033
1034 void GenCollectedHeap::save_marks() {
1035 _young_gen->save_marks();
1036 _old_gen->save_marks();
1037 }
1038
1039 GenCollectedHeap* GenCollectedHeap::heap() {
1040 assert(_gch != NULL, "Uninitialized access to GenCollectedHeap::heap()");
1041 assert(_gch->kind() == CollectedHeap::GenCollectedHeap, "not a generational heap");
1042 return _gch;
1043 }
1044
1045
1046 void GenCollectedHeap::prepare_for_compaction() {
1047 guarantee(_n_gens = 2, "Wrong number of generations");
1048 Generation* old_gen = _old_gen;
1049 // Start by compacting into same gen.
1050 CompactPoint cp(old_gen);
1051 old_gen->prepare_for_compaction(&cp);
1052 Generation* young_gen = _young_gen;
1053 young_gen->prepare_for_compaction(&cp);
1054 }
1055
1056 GCStats* GenCollectedHeap::gc_stats(int level) const {
1057 if (level == 0) {
1058 return _young_gen->gc_stats();
1059 } else {
1060 return _old_gen->gc_stats();
1061 }
1062 }
1063
1064 void GenCollectedHeap::verify(bool silent, VerifyOption option /* ignored */) {
1065 if (!silent) {
1066 gclog_or_tty->print("%s", _old_gen->name());
1067 gclog_or_tty->print(" ");
1068 }
1069 _old_gen->verify();
1070
1071 if (!silent) {
1072 gclog_or_tty->print("%s", _young_gen->name());
1073 gclog_or_tty->print(" ");
1074 }
1075 _young_gen->verify();
1076
1077 if (!silent) {
1078 gclog_or_tty->print("remset ");
1079 }
1080 rem_set()->verify();
1081 }
1082
1083 void GenCollectedHeap::print_on(outputStream* st) const {
1084 _young_gen->print_on(st);
1085 _old_gen->print_on(st);
1086 MetaspaceAux::print_on(st);
1087 }
1088
1089 void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const {
1090 if (workers() != NULL) {
1091 workers()->threads_do(tc);
1092 }
1093 #if INCLUDE_ALL_GCS
1094 if (UseConcMarkSweepGC) {
1095 ConcurrentMarkSweepThread::threads_do(tc);
1096 }
1097 #endif // INCLUDE_ALL_GCS
1098 }
1099
1100 void GenCollectedHeap::print_gc_threads_on(outputStream* st) const {
1101 #if INCLUDE_ALL_GCS
1102 if (UseConcMarkSweepGC) {
1103 workers()->print_worker_threads_on(st);
1104 ConcurrentMarkSweepThread::print_all_on(st);
1105 }
1106 #endif // INCLUDE_ALL_GCS
1107 }
1108
1109 void GenCollectedHeap::print_on_error(outputStream* st) const {
1110 this->CollectedHeap::print_on_error(st);
1111
1112 #if INCLUDE_ALL_GCS
1113 if (UseConcMarkSweepGC) {
1114 st->cr();
1115 CMSCollector::print_on_error(st);
1116 }
1117 #endif // INCLUDE_ALL_GCS
1118 }
1119
1120 void GenCollectedHeap::print_tracing_info() const {
1121 if (TraceYoungGenTime) {
1122 get_gen(0)->print_summary_info();
1123 }
1124 if (TraceOldGenTime) {
1125 get_gen(1)->print_summary_info();
1126 }
1127 }
1128
1129 void GenCollectedHeap::print_heap_change(size_t prev_used) const {
1130 if (PrintGCDetails && Verbose) {
1131 gclog_or_tty->print(" " SIZE_FORMAT
1132 "->" SIZE_FORMAT
1133 "(" SIZE_FORMAT ")",
1134 prev_used, used(), capacity());
1135 } else {
1136 gclog_or_tty->print(" " SIZE_FORMAT "K"
1137 "->" SIZE_FORMAT "K"
1138 "(" SIZE_FORMAT "K)",
1139 prev_used / K, used() / K, capacity() / K);
1140 }
1141 }
1142
1143 class GenGCPrologueClosure: public GenCollectedHeap::GenClosure {
1144 private:
1145 bool _full;
1146 public:
1147 void do_generation(Generation* gen) {
1148 gen->gc_prologue(_full);
1149 }
1150 GenGCPrologueClosure(bool full) : _full(full) {};
1151 };
1152
1153 void GenCollectedHeap::gc_prologue(bool full) {
1154 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer");
1155
1156 always_do_update_barrier = false;
1157 // Fill TLAB's and such
1158 CollectedHeap::accumulate_statistics_all_tlabs();
1159 ensure_parsability(true); // retire TLABs
1160
1161 // Walk generations
1162 GenGCPrologueClosure blk(full);
1163 generation_iterate(&blk, false); // not old-to-young.
1164 };
1165
1166 class GenGCEpilogueClosure: public GenCollectedHeap::GenClosure {
1167 private:
1168 bool _full;
1169 public:
1170 void do_generation(Generation* gen) {
1171 gen->gc_epilogue(_full);
1172 }
1173 GenGCEpilogueClosure(bool full) : _full(full) {};
1174 };
1175
1176 void GenCollectedHeap::gc_epilogue(bool full) {
1177 #ifdef COMPILER2
1178 assert(DerivedPointerTable::is_empty(), "derived pointer present");
1179 size_t actual_gap = pointer_delta((HeapWord*) (max_uintx-3), *(end_addr()));
1180 guarantee(actual_gap > (size_t)FastAllocateSizeLimit, "inline allocation wraps");
1181 #endif /* COMPILER2 */
1182
1183 resize_all_tlabs();
1184
1185 GenGCEpilogueClosure blk(full);
1186 generation_iterate(&blk, false); // not old-to-young.
1187
1188 if (!CleanChunkPoolAsync) {
1189 Chunk::clean_chunk_pool();
1190 }
1191
1192 MetaspaceCounters::update_performance_counters();
1193 CompressedClassSpaceCounters::update_performance_counters();
1194
1195 always_do_update_barrier = UseConcMarkSweepGC;
1196 };
1197
1198 #ifndef PRODUCT
1199 class GenGCSaveTopsBeforeGCClosure: public GenCollectedHeap::GenClosure {
1200 private:
1201 public:
1202 void do_generation(Generation* gen) {
1203 gen->record_spaces_top();
1204 }
1205 };
1206
1207 void GenCollectedHeap::record_gen_tops_before_GC() {
1208 if (ZapUnusedHeapArea) {
1209 GenGCSaveTopsBeforeGCClosure blk;
1210 generation_iterate(&blk, false); // not old-to-young.
1211 }
1212 }
1213 #endif // not PRODUCT
1214
1215 class GenEnsureParsabilityClosure: public GenCollectedHeap::GenClosure {
1216 public:
1217 void do_generation(Generation* gen) {
1218 gen->ensure_parsability();
1219 }
1220 };
1221
1222 void GenCollectedHeap::ensure_parsability(bool retire_tlabs) {
1223 CollectedHeap::ensure_parsability(retire_tlabs);
1224 GenEnsureParsabilityClosure ep_cl;
1225 generation_iterate(&ep_cl, false);
1226 }
1227
1228 oop GenCollectedHeap::handle_failed_promotion(Generation* old_gen,
1229 oop obj,
1230 size_t obj_size) {
1231 guarantee(old_gen->level() == 1, "We only get here with an old generation");
1232 assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
1233 HeapWord* result = NULL;
1234
1235 result = old_gen->expand_and_allocate(obj_size, false);
1236
1237 if (result != NULL) {
1238 Copy::aligned_disjoint_words((HeapWord*)obj, result, obj_size);
1239 }
1240 return oop(result);
1241 }
1242
1243 class GenTimeOfLastGCClosure: public GenCollectedHeap::GenClosure {
1244 jlong _time; // in ms
1245 jlong _now; // in ms
1246
1247 public:
1248 GenTimeOfLastGCClosure(jlong now) : _time(now), _now(now) { }
1249
1250 jlong time() { return _time; }
1251
1252 void do_generation(Generation* gen) {
1253 _time = MIN2(_time, gen->time_of_last_gc(_now));
1254 }
1255 };
1256
1257 jlong GenCollectedHeap::millis_since_last_gc() {
1258 // We need a monotonically non-decreasing time in ms but
1259 // os::javaTimeMillis() does not guarantee monotonicity.
1260 jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
1261 GenTimeOfLastGCClosure tolgc_cl(now);
1262 // iterate over generations getting the oldest
1263 // time that a generation was collected
1264 generation_iterate(&tolgc_cl, false);
1265
1266 // javaTimeNanos() is guaranteed to be monotonically non-decreasing
1267 // provided the underlying platform provides such a time source
1268 // (and it is bug free). So we still have to guard against getting
1269 // back a time later than 'now'.
1270 jlong retVal = now - tolgc_cl.time();
1271 if (retVal < 0) {
1272 NOT_PRODUCT(warning("time warp: "INT64_FORMAT, (int64_t) retVal);)
1273 return 0;
1274 }
1275 return retVal;
1276 }