summaryrefslogtreecommitdiffstats
path: root/js/src/gc/Zone.cpp
blob: 13324d7e43663868afd803670510a095e97cb624 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=8 sts=2 et sw=2 tw=80:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "gc/Zone.h"
#include "js/shadow/Zone.h"  // JS::shadow::Zone

#include "mozilla/Sprintf.h"
#include "mozilla/TimeStamp.h"

#include <type_traits>

#include "gc/FinalizationObservers.h"
#include "gc/GCContext.h"
#include "gc/PublicIterators.h"
#include "jit/BaselineIC.h"
#include "jit/BaselineJIT.h"
#include "jit/Invalidation.h"
#include "jit/JitScript.h"
#include "jit/JitZone.h"
#include "vm/Runtime.h"
#include "vm/Time.h"

#include "debugger/DebugAPI-inl.h"
#include "gc/GC-inl.h"
#include "gc/Marking-inl.h"
#include "gc/Nursery-inl.h"
#include "gc/StableCellHasher-inl.h"
#include "gc/WeakMap-inl.h"
#include "vm/JSScript-inl.h"
#include "vm/Realm-inl.h"

using namespace js;
using namespace js::gc;

Zone* const Zone::NotOnList = reinterpret_cast<Zone*>(1);

ZoneAllocator::ZoneAllocator(JSRuntime* rt, Kind kind)
    : JS::shadow::Zone(rt, rt->gc.marker().tracer(), kind),
      jitHeapThreshold(size_t(jit::MaxCodeBytesPerProcess * 0.8)) {}

ZoneAllocator::~ZoneAllocator() {
#ifdef DEBUG
  mallocTracker.checkEmptyOnDestroy();
  MOZ_ASSERT(gcHeapSize.bytes() == 0);
  MOZ_ASSERT(mallocHeapSize.bytes() == 0);
  MOZ_ASSERT(jitHeapSize.bytes() == 0);
#endif
}

void ZoneAllocator::fixupAfterMovingGC() {
#ifdef DEBUG
  mallocTracker.fixupAfterMovingGC();
#endif
}

void js::ZoneAllocator::updateSchedulingStateOnGCStart() {
  gcHeapSize.updateOnGCStart();
  mallocHeapSize.updateOnGCStart();
  jitHeapSize.updateOnGCStart();
  perZoneGCTime = mozilla::TimeDuration::Zero();
}

void js::ZoneAllocator::updateGCStartThresholds(GCRuntime& gc) {
  bool isAtomsZone = JS::Zone::from(this)->isAtomsZone();
  gcHeapThreshold.updateStartThreshold(
      gcHeapSize.retainedBytes(), smoothedAllocationRate.ref(),
      smoothedCollectionRate.ref(), gc.tunables, gc.schedulingState,
      isAtomsZone);

  mallocHeapThreshold.updateStartThreshold(mallocHeapSize.retainedBytes(),
                                           gc.tunables, gc.schedulingState);
}

void js::ZoneAllocator::setGCSliceThresholds(GCRuntime& gc,
                                             bool waitingOnBGTask) {
  gcHeapThreshold.setSliceThreshold(this, gcHeapSize, gc.tunables,
                                    waitingOnBGTask);
  mallocHeapThreshold.setSliceThreshold(this, mallocHeapSize, gc.tunables,
                                        waitingOnBGTask);
  jitHeapThreshold.setSliceThreshold(this, jitHeapSize, gc.tunables,
                                     waitingOnBGTask);
}

void js::ZoneAllocator::clearGCSliceThresholds() {
  gcHeapThreshold.clearSliceThreshold();
  mallocHeapThreshold.clearSliceThreshold();
  jitHeapThreshold.clearSliceThreshold();
}

bool ZoneAllocator::addSharedMemory(void* mem, size_t nbytes, MemoryUse use) {
  // nbytes can be zero here for SharedArrayBuffers.

  MOZ_ASSERT(CurrentThreadCanAccessRuntime(runtime_));

  auto ptr = sharedMemoryUseCounts.lookupForAdd(mem);
  MOZ_ASSERT_IF(ptr, ptr->value().use == use);

  if (!ptr && !sharedMemoryUseCounts.add(ptr, mem, gc::SharedMemoryUse(use))) {
    return false;
  }

  ptr->value().count++;

  // Allocations can grow, so add any increase over the previous size and record
  // the new size.
  if (nbytes > ptr->value().nbytes) {
    mallocHeapSize.addBytes(nbytes - ptr->value().nbytes);
    ptr->value().nbytes = nbytes;
  }

  maybeTriggerGCOnMalloc();

  return true;
}

void ZoneAllocator::removeSharedMemory(void* mem, size_t nbytes,
                                       MemoryUse use) {
  // nbytes can be zero here for SharedArrayBuffers.

  MOZ_ASSERT(CurrentThreadCanAccessRuntime(runtime_));
  MOZ_ASSERT(CurrentThreadIsGCFinalizing());

  auto ptr = sharedMemoryUseCounts.lookup(mem);

  MOZ_ASSERT(ptr);
  MOZ_ASSERT(ptr->value().count != 0);
  MOZ_ASSERT(ptr->value().use == use);
  MOZ_ASSERT(ptr->value().nbytes >= nbytes);

  ptr->value().count--;
  if (ptr->value().count == 0) {
    mallocHeapSize.removeBytes(ptr->value().nbytes, true);
    sharedMemoryUseCounts.remove(ptr);
  }
}

template <TrackingKind kind>
void js::TrackedAllocPolicy<kind>::decMemory(size_t nbytes) {
  bool updateRetainedSize = false;
  if constexpr (kind == TrackingKind::Cell) {
    // Only subtract freed cell memory from retained size for cell associations
    // during sweeping.
    JS::GCContext* gcx = TlsGCContext.get();
    updateRetainedSize = gcx->isFinalizing();
  }

  zone_->decNonGCMemory(this, nbytes, MemoryUse::TrackedAllocPolicy,
                        updateRetainedSize);
}

namespace js {
template class TrackedAllocPolicy<TrackingKind::Zone>;
template class TrackedAllocPolicy<TrackingKind::Cell>;
}  // namespace js

JS::Zone::Zone(JSRuntime* rt, Kind kind)
    : ZoneAllocator(rt, kind),
      arenas(this),
      data(nullptr),
      suppressAllocationMetadataBuilder(false),
      allocNurseryObjects_(true),
      allocNurseryStrings_(true),
      allocNurseryBigInts_(true),
      pretenuring(this),
      crossZoneStringWrappers_(this),
      gcEphemeronEdges_(SystemAllocPolicy(), rt->randomHashCodeScrambler()),
      gcNurseryEphemeronEdges_(SystemAllocPolicy(),
                               rt->randomHashCodeScrambler()),
      shapeZone_(this),
      gcScheduled_(false),
      gcScheduledSaved_(false),
      gcPreserveCode_(false),
      keepPropMapTables_(false),
      wasCollected_(false),
      listNext_(NotOnList),
      keptObjects(this) {
  /* Ensure that there are no vtables to mess us up here. */
  MOZ_ASSERT(reinterpret_cast<JS::shadow::Zone*>(this) ==
             static_cast<JS::shadow::Zone*>(this));
  MOZ_ASSERT_IF(isAtomsZone(), rt->gc.zones().empty());

  updateGCStartThresholds(rt->gc);
  rt->gc.nursery().setAllocFlagsForZone(this);
}

Zone::~Zone() {
  MOZ_ASSERT_IF(regExps_.ref(), regExps().empty());

  MOZ_ASSERT(numRealmsWithAllocMetadataBuilder_ == 0);

  DebugAPI::deleteDebugScriptMap(debugScriptMap);
  js_delete(finalizationObservers_.ref().release());

  MOZ_ASSERT(gcWeakMapList().isEmpty());
  MOZ_ASSERT(objectsWithWeakPointers.ref().empty());

  JSRuntime* rt = runtimeFromAnyThread();
  if (this == rt->gc.systemZone) {
    MOZ_ASSERT(isSystemZone());
    rt->gc.systemZone = nullptr;
  }

  js_delete(jitZone_.ref());
}

bool Zone::init() {
  regExps_.ref() = make_unique<RegExpZone>(this);
  return regExps_.ref() && gcEphemeronEdges().init() &&
         gcNurseryEphemeronEdges().init();
}

void Zone::setNeedsIncrementalBarrier(bool needs) {
  needsIncrementalBarrier_ = needs;
}

void Zone::changeGCState(GCState prev, GCState next) {
  MOZ_ASSERT(RuntimeHeapIsBusy());
  MOZ_ASSERT(gcState() == prev);

  // This can be called when barriers have been temporarily disabled by
  // AutoDisableBarriers. In that case, don't update needsIncrementalBarrier_
  // and barriers will be re-enabled by ~AutoDisableBarriers() if necessary.
  bool barriersDisabled = isGCMarking() && !needsIncrementalBarrier();

  gcState_ = next;

  // Update the barriers state when we transition between marking and
  // non-marking states, unless barriers have been disabled.
  if (!barriersDisabled) {
    needsIncrementalBarrier_ = isGCMarking();
  }
}

template <class Pred>
static void EraseIf(js::gc::EphemeronEdgeVector& entries, Pred pred) {
  auto* begin = entries.begin();
  auto* const end = entries.end();

  auto* newEnd = begin;
  for (auto* p = begin; p != end; p++) {
    if (!pred(*p)) {
      *newEnd++ = *p;
    }
  }

  size_t removed = end - newEnd;
  entries.shrinkBy(removed);
}

static void SweepEphemeronEdgesWhileMinorSweeping(
    js::gc::EphemeronEdgeVector& entries) {
  EraseIf(entries, [](js::gc::EphemeronEdge& edge) -> bool {
    return IsAboutToBeFinalizedDuringMinorSweep(&edge.target);
  });
}

void Zone::sweepAfterMinorGC(JSTracer* trc) {
  sweepEphemeronTablesAfterMinorGC();
  crossZoneStringWrappers().sweepAfterMinorGC(trc);

  for (CompartmentsInZoneIter comp(this); !comp.done(); comp.next()) {
    comp->sweepAfterMinorGC(trc);
  }
}

void Zone::sweepEphemeronTablesAfterMinorGC() {
  for (auto r = gcNurseryEphemeronEdges().mutableAll(); !r.empty();
       r.popFront()) {
    // Sweep gcNurseryEphemeronEdges to move live (forwarded) keys to
    // gcEphemeronEdges, scanning through all the entries for such keys to
    // update them.
    //
    // Forwarded and dead keys may also appear in their delegates' entries,
    // so sweep those too (see below.)

    // The tricky case is when the key has a delegate that was already
    // tenured. Then it will be in its compartment's gcEphemeronEdges, but we
    // still need to update the key (which will be in the entries
    // associated with it.)
    gc::Cell* key = r.front().key;
    MOZ_ASSERT(!key->isTenured());
    if (!Nursery::getForwardedPointer(&key)) {
      // Dead nursery cell => discard.
      continue;
    }

    // Key been moved. The value is an array of <color,cell> pairs; update all
    // cells in that array.
    EphemeronEdgeVector& entries = r.front().value;
    SweepEphemeronEdgesWhileMinorSweeping(entries);

    // Live (moved) nursery cell. Append entries to gcEphemeronEdges.
    EphemeronEdgeTable& tenuredEdges = gcEphemeronEdges();
    AutoEnterOOMUnsafeRegion oomUnsafe;
    auto* entry = tenuredEdges.getOrAdd(key);
    if (!entry) {
      oomUnsafe.crash("Failed to tenure weak keys entry");
    }

    if (!entry->value.appendAll(entries)) {
      oomUnsafe.crash("Failed to tenure weak keys entry");
    }

    // If the key has a delegate, then it will map to a WeakKeyEntryVector
    // containing the key that needs to be updated.

    JSObject* delegate = gc::detail::GetDelegate(key->as<JSObject>());
    if (!delegate) {
      continue;
    }
    MOZ_ASSERT(delegate->isTenured());

    // If delegate was formerly nursery-allocated, we will sweep its entries
    // when we visit its gcNurseryEphemeronEdges (if we haven't already). Note
    // that we don't know the nursery address of the delegate, since the
    // location it was stored in has already been updated.
    //
    // Otherwise, it will be in gcEphemeronEdges and we sweep it here.
    auto* p = delegate->zone()->gcEphemeronEdges().get(delegate);
    if (p) {
      SweepEphemeronEdgesWhileMinorSweeping(p->value);
    }
  }

  if (!gcNurseryEphemeronEdges().clear()) {
    AutoEnterOOMUnsafeRegion oomUnsafe;
    oomUnsafe.crash("OOM while clearing gcNurseryEphemeronEdges.");
  }
}

void Zone::traceWeakCCWEdges(JSTracer* trc) {
  crossZoneStringWrappers().traceWeak(trc);
  for (CompartmentsInZoneIter comp(this); !comp.done(); comp.next()) {
    comp->traceCrossCompartmentObjectWrapperEdges(trc);
  }
}

/* static */
void Zone::fixupAllCrossCompartmentWrappersAfterMovingGC(JSTracer* trc) {
  MOZ_ASSERT(trc->runtime()->gc.isHeapCompacting());

  for (ZonesIter zone(trc->runtime(), WithAtoms); !zone.done(); zone.next()) {
    // Trace the wrapper map to update keys (wrapped values) in other
    // compartments that may have been moved.
    zone->crossZoneStringWrappers().traceWeak(trc);

    for (CompartmentsInZoneIter comp(zone); !comp.done(); comp.next()) {
      comp->fixupCrossCompartmentObjectWrappersAfterMovingGC(trc);
    }
  }
}

void Zone::dropStringWrappersOnGC() {
  MOZ_ASSERT(JS::RuntimeHeapIsCollecting());
  crossZoneStringWrappers().clear();
}

#ifdef JSGC_HASH_TABLE_CHECKS

void Zone::checkAllCrossCompartmentWrappersAfterMovingGC() {
  checkStringWrappersAfterMovingGC();
  for (CompartmentsInZoneIter comp(this); !comp.done(); comp.next()) {
    comp->checkObjectWrappersAfterMovingGC();
  }
}

void Zone::checkStringWrappersAfterMovingGC() {
  CheckTableAfterMovingGC(crossZoneStringWrappers(), [this](const auto& entry) {
    JSString* key = entry.key().get();
    CheckGCThingAfterMovingGC(key);  // Keys may be in a different zone.
    CheckGCThingAfterMovingGC(entry.value().unbarrieredGet(), this);
    return key;
  });
}
#endif

void Zone::discardJitCode(JS::GCContext* gcx, const DiscardOptions& options) {
  if (!isPreservingCode()) {
    forceDiscardJitCode(gcx, options);
  }
}

void Zone::forceDiscardJitCode(JS::GCContext* gcx,
                               const DiscardOptions& options) {
  if (!jitZone()) {
    return;
  }

  if (options.discardJitScripts) {
    lastDiscardedCodeTime_ = mozilla::TimeStamp::Now();
  }

  // Copy Baseline IC stubs that are active on the stack to a new LifoAlloc.
  // After freeing stub memory, these chunks are then transferred to the
  // zone-wide allocator.
  jit::ICStubSpace newStubSpace;

#ifdef DEBUG
  // Assert no ICScripts are marked as active.
  jitZone()->forEachJitScript([](jit::JitScript* jitScript) {
    MOZ_ASSERT(!jitScript->hasActiveICScript());
  });
#endif

  // Mark ICScripts on the stack as active and copy active Baseline stubs.
  jit::MarkActiveICScriptsAndCopyStubs(this, newStubSpace);

  // Invalidate all Ion code in this zone.
  jit::InvalidateAll(gcx, this);

  jitZone()->forEachJitScript<jit::IncludeDyingScripts>(
      [&](jit::JitScript* jitScript) {
        JSScript* script = jitScript->owningScript();
        jit::FinishInvalidation(gcx, script);

        // Discard baseline script if it's not marked as active.
        if (jitScript->hasBaselineScript() &&
            !jitScript->icScript()->active()) {
          jit::FinishDiscardBaselineScript(gcx, script);
        }

#ifdef JS_CACHEIR_SPEW
        maybeUpdateWarmUpCount(script);
#endif

        // Warm-up counter for scripts are reset on GC. After discarding code we
        // need to let it warm back up to get information such as which
        // opcodes are setting array holes or accessing getter properties.
        script->resetWarmUpCounterForGC();

        // Try to release the script's JitScript. This should happen after
        // releasing JIT code because we can't do this when the script still has
        // JIT code.
        if (options.discardJitScripts) {
          script->maybeReleaseJitScript(gcx);
          jitScript = script->maybeJitScript();
          if (!jitScript) {
            // Try to discard the ScriptCounts too.
            if (!script->realm()->collectCoverageForDebug() &&
                !gcx->runtime()->profilingScripts) {
              script->destroyScriptCounts();
            }
            return;  // Continue script loop.
          }
        }

        // If we did not release the JitScript, we need to purge IC stubs
        // because the ICStubSpace will be purged below. Also purge all
        // trial-inlined ICScripts that are not active on the stack.
        jitScript->purgeInactiveICScripts();
        jitScript->purgeStubs(script, newStubSpace);

        if (options.resetNurseryAllocSites ||
            options.resetPretenuredAllocSites) {
          jitScript->resetAllocSites(options.resetNurseryAllocSites,
                                     options.resetPretenuredAllocSites);
        }

        // Reset the active flag of each ICScript.
        jitScript->resetAllActiveFlags();

        // Optionally trace weak edges in remaining JitScripts.
        if (options.traceWeakJitScripts) {
          jitScript->traceWeak(options.traceWeakJitScripts);
        }
      });

  // Also clear references to jit code from RegExpShared cells at this point.
  // This avoid holding onto ExecutablePools.
  for (auto regExp = cellIterUnsafe<RegExpShared>(); !regExp.done();
       regExp.next()) {
    regExp->discardJitCode();
  }

  /*
   * When scripts contain pointers to nursery things, the store buffer
   * can contain entries that point into the optimized stub space. Since
   * this method can be called outside the context of a GC, this situation
   * could result in us trying to mark invalid store buffer entries.
   *
   * Defer freeing any allocated blocks until after the next minor GC.
   */
  jitZone()->stubSpace()->freeAllAfterMinorGC(this);
  jitZone()->stubSpace()->transferFrom(newStubSpace);
  jitZone()->purgeIonCacheIRStubInfo();

  // Generate a profile marker
  if (gcx->runtime()->geckoProfiler().enabled()) {
    char discardingJitScript = options.discardJitScripts ? 'Y' : 'N';
    char discardingBaseline = 'Y';
    char discardingIon = 'Y';

    char discardingRegExp = 'Y';
    char discardingNurserySites = options.resetNurseryAllocSites ? 'Y' : 'N';
    char discardingPretenuredSites =
        options.resetPretenuredAllocSites ? 'Y' : 'N';

    char buf[100];
    SprintfLiteral(buf,
                   "JitScript:%c Baseline:%c Ion:%c "
                   "RegExp:%c NurserySites:%c PretenuredSites:%c",
                   discardingJitScript, discardingBaseline, discardingIon,
                   discardingRegExp, discardingNurserySites,
                   discardingPretenuredSites);
    gcx->runtime()->geckoProfiler().markEvent("DiscardJit", buf);
  }
}

void JS::Zone::resetAllocSitesAndInvalidate(bool resetNurserySites,
                                            bool resetPretenuredSites) {
  MOZ_ASSERT(resetNurserySites || resetPretenuredSites);

  if (!jitZone()) {
    return;
  }

  JSContext* cx = runtime_->mainContextFromOwnThread();
  jitZone()->forEachJitScript<jit::IncludeDyingScripts>(
      [&](jit::JitScript* jitScript) {
        if (jitScript->resetAllocSites(resetNurserySites,
                                       resetPretenuredSites)) {
          JSScript* script = jitScript->owningScript();
          CancelOffThreadIonCompile(script);
          if (script->hasIonScript()) {
            jit::Invalidate(cx, script,
                            /* resetUses = */ true,
                            /* cancelOffThread = */ true);
          }
        }
      });
}

void JS::Zone::traceWeakJitScripts(JSTracer* trc) {
  if (jitZone()) {
    jitZone()->forEachJitScript(
        [&](jit::JitScript* jitScript) { jitScript->traceWeak(trc); });
  }
}

void JS::Zone::beforeClearDelegateInternal(JSObject* wrapper,
                                           JSObject* delegate) {
  // 'delegate' is no longer the delegate of 'wrapper'.
  MOZ_ASSERT(js::gc::detail::GetDelegate(wrapper) == delegate);
  MOZ_ASSERT(needsIncrementalBarrier());
  MOZ_ASSERT(!RuntimeFromMainThreadIsHeapMajorCollecting(this));

  // If |wrapper| might be a key in a weak map, trigger a barrier to account for
  // the removal of the automatically added edge from delegate to wrapper.
  if (HasUniqueId(wrapper)) {
    PreWriteBarrier(wrapper);
  }
}

#ifdef JSGC_HASH_TABLE_CHECKS
void JS::Zone::checkUniqueIdTableAfterMovingGC() {
  CheckTableAfterMovingGC(uniqueIds(), [this](const auto& entry) {
    js::gc::CheckGCThingAfterMovingGC(entry.key(), this);
    return entry.key();
  });
}
#endif

js::jit::JitZone* Zone::createJitZone(JSContext* cx) {
  MOZ_ASSERT(!jitZone_);
#ifndef ENABLE_PORTABLE_BASELINE_INTERP
  MOZ_ASSERT(cx->runtime()->hasJitRuntime());
#endif

  auto jitZone = cx->make_unique<jit::JitZone>(allocNurseryStrings());
  if (!jitZone) {
    return nullptr;
  }

  jitZone_ = jitZone.release();
  return jitZone_;
}

bool Zone::hasMarkedRealms() {
  for (RealmsInZoneIter realm(this); !realm.done(); realm.next()) {
    if (realm->marked()) {
      return true;
    }
  }
  return false;
}

void Zone::notifyObservingDebuggers() {
  AutoAssertNoGC nogc;
  MOZ_ASSERT(JS::RuntimeHeapIsCollecting(),
             "This method should be called during GC.");

  JSRuntime* rt = runtimeFromMainThread();

  for (RealmsInZoneIter realms(this); !realms.done(); realms.next()) {
    GlobalObject* global = realms->unsafeUnbarrieredMaybeGlobal();
    if (!global) {
      continue;
    }

    DebugAPI::notifyParticipatesInGC(global, rt->gc.majorGCCount());
  }
}

bool Zone::isOnList() const { return listNext_ != NotOnList; }

Zone* Zone::nextZone() const {
  MOZ_ASSERT(isOnList());
  return listNext_;
}

void Zone::fixupAfterMovingGC() {
  ZoneAllocator::fixupAfterMovingGC();
  shapeZone().fixupPropMapShapeTableAfterMovingGC();
}

void Zone::purgeAtomCache() {
  atomCache_.ref().reset();

  // Also purge the dtoa caches so that subsequent lookups populate atom
  // cache too.
  for (RealmsInZoneIter r(this); !r.done(); r.next()) {
    r->dtoaCache.purge();
  }
}

void Zone::addSizeOfIncludingThis(
    mozilla::MallocSizeOf mallocSizeOf, size_t* zoneObject, JS::CodeSizes* code,
    size_t* regexpZone, size_t* jitZone, size_t* cacheIRStubs,
    size_t* uniqueIdMap, size_t* initialPropMapTable, size_t* shapeTables,
    size_t* atomsMarkBitmaps, size_t* compartmentObjects,
    size_t* crossCompartmentWrappersTables, size_t* compartmentsPrivateData,
    size_t* scriptCountsMapArg) {
  *zoneObject += mallocSizeOf(this);
  *regexpZone += regExps().sizeOfIncludingThis(mallocSizeOf);
  if (jitZone_) {
    jitZone_->addSizeOfIncludingThis(mallocSizeOf, code, jitZone, cacheIRStubs);
  }
  *uniqueIdMap += uniqueIds().shallowSizeOfExcludingThis(mallocSizeOf);
  shapeZone().addSizeOfExcludingThis(mallocSizeOf, initialPropMapTable,
                                     shapeTables);
  *atomsMarkBitmaps += markedAtoms().sizeOfExcludingThis(mallocSizeOf);
  *crossCompartmentWrappersTables +=
      crossZoneStringWrappers().sizeOfExcludingThis(mallocSizeOf);

  for (CompartmentsInZoneIter comp(this); !comp.done(); comp.next()) {
    comp->addSizeOfIncludingThis(mallocSizeOf, compartmentObjects,
                                 crossCompartmentWrappersTables,
                                 compartmentsPrivateData);
  }

  if (scriptCountsMap) {
    *scriptCountsMapArg +=
        scriptCountsMap->shallowSizeOfIncludingThis(mallocSizeOf);
    for (auto r = scriptCountsMap->all(); !r.empty(); r.popFront()) {
      *scriptCountsMapArg +=
          r.front().value()->sizeOfIncludingThis(mallocSizeOf);
    }
  }
}

void* ZoneAllocator::onOutOfMemory(js::AllocFunction allocFunc,
                                   arena_id_t arena, size_t nbytes,
                                   void* reallocPtr) {
  if (!js::CurrentThreadCanAccessRuntime(runtime_)) {
    return nullptr;
  }
  // The analysis sees that JSRuntime::onOutOfMemory could report an error,
  // which with a JSErrorInterceptor could GC. But we're passing a null cx (to
  // a default parameter) so the error will not be reported.
  JS::AutoSuppressGCAnalysis suppress;
  return runtimeFromMainThread()->onOutOfMemory(allocFunc, arena, nbytes,
                                                reallocPtr);
}

void ZoneAllocator::reportAllocationOverflow() const {
  js::ReportAllocationOverflow(static_cast<JSContext*>(nullptr));
}

ZoneList::ZoneList() : head(nullptr), tail(nullptr) {}

ZoneList::ZoneList(Zone* zone) : head(zone), tail(zone) {
  MOZ_RELEASE_ASSERT(!zone->isOnList());
  zone->listNext_ = nullptr;
}

ZoneList::~ZoneList() { MOZ_ASSERT(isEmpty()); }

void ZoneList::check() const {
#ifdef DEBUG
  MOZ_ASSERT((head == nullptr) == (tail == nullptr));
  if (!head) {
    return;
  }

  Zone* zone = head;
  for (;;) {
    MOZ_ASSERT(zone && zone->isOnList());
    if (zone == tail) break;
    zone = zone->listNext_;
  }
  MOZ_ASSERT(!zone->listNext_);
#endif
}

bool ZoneList::isEmpty() const { return head == nullptr; }

Zone* ZoneList::front() const {
  MOZ_ASSERT(!isEmpty());
  MOZ_ASSERT(head->isOnList());
  return head;
}

void ZoneList::prepend(Zone* zone) { prependList(ZoneList(zone)); }

void ZoneList::append(Zone* zone) { appendList(ZoneList(zone)); }

void ZoneList::prependList(ZoneList&& other) {
  check();
  other.check();

  if (other.isEmpty()) {
    return;
  }

  MOZ_ASSERT(tail != other.tail);

  if (!isEmpty()) {
    other.tail->listNext_ = head;
  } else {
    tail = other.tail;
  }
  head = other.head;

  other.head = nullptr;
  other.tail = nullptr;
}

void ZoneList::appendList(ZoneList&& other) {
  check();
  other.check();

  if (other.isEmpty()) {
    return;
  }

  MOZ_ASSERT(tail != other.tail);

  if (!isEmpty()) {
    tail->listNext_ = other.head;
  } else {
    head = other.head;
  }
  tail = other.tail;

  other.head = nullptr;
  other.tail = nullptr;
}

Zone* ZoneList::removeFront() {
  MOZ_ASSERT(!isEmpty());
  check();

  Zone* front = head;
  head = head->listNext_;
  if (!head) {
    tail = nullptr;
  }

  front->listNext_ = Zone::NotOnList;

  return front;
}

void ZoneList::clear() {
  while (!isEmpty()) {
    removeFront();
  }
}

JS_PUBLIC_API void js::gc::RegisterWeakCache(JS::Zone* zone,
                                             WeakCacheBase* cachep) {
  zone->registerWeakCache(cachep);
}

void Zone::traceRootsInMajorGC(JSTracer* trc) {
  if (trc->isMarkingTracer() && !isGCMarking()) {
    return;
  }

  // Trace zone script-table roots. See comment below for justification re:
  // calling this only during major (non-nursery) collections.
  traceScriptTableRoots(trc);

  if (FinalizationObservers* observers = finalizationObservers()) {
    observers->traceRoots(trc);
  }
}

void Zone::traceScriptTableRoots(JSTracer* trc) {
  static_assert(std::is_convertible_v<BaseScript*, gc::TenuredCell*>,
                "BaseScript must not be nursery-allocated for script-table "
                "tracing to work");

  // Performance optimization: the script-table keys are JSScripts, which
  // cannot be in the nursery, so we can skip this tracing if we are only in a
  // minor collection. We static-assert this fact above.
  MOZ_ASSERT(!JS::RuntimeHeapIsMinorCollecting());

  // N.B.: the script-table keys are weak *except* in an exceptional case: when
  // then --dump-bytecode command line option or the PCCount JSFriend API is
  // used, then the scripts for all counts must remain alive. We only trace
  // when the `trc->runtime()->profilingScripts` flag is set. This flag is
  // cleared in JSRuntime::destroyRuntime() during shutdown to ensure that
  // scripts are collected before the runtime goes away completely.
  if (scriptCountsMap && trc->runtime()->profilingScripts) {
    for (ScriptCountsMap::Range r = scriptCountsMap->all(); !r.empty();
         r.popFront()) {
      BaseScript* script = r.front().key();
      MOZ_ASSERT(script->hasScriptCounts());
      TraceRoot(trc, &script, "profilingScripts");
    }
  }

  // Trace the debugger's DebugScript weak map.
  if (debugScriptMap) {
    DebugAPI::traceDebugScriptMap(trc, debugScriptMap);
  }
}

void Zone::fixupScriptMapsAfterMovingGC(JSTracer* trc) {
  // Map entries are removed by BaseScript::finalize, but we need to update the
  // script pointers here in case they are moved by the GC.

  if (scriptCountsMap) {
    scriptCountsMap->traceWeak(trc);
  }

  if (scriptLCovMap) {
    scriptLCovMap->traceWeak(trc);
  }

#ifdef MOZ_VTUNE
  if (scriptVTuneIdMap) {
    scriptVTuneIdMap->traceWeak(trc);
  }
#endif

#ifdef JS_CACHEIR_SPEW
  if (scriptFinalWarmUpCountMap) {
    scriptFinalWarmUpCountMap->traceWeak(trc);
  }
#endif
}

#ifdef JSGC_HASH_TABLE_CHECKS
void Zone::checkScriptMapsAfterMovingGC() {
  // |debugScriptMap| is checked automatically because it is s a WeakMap.

  if (scriptCountsMap) {
    CheckTableAfterMovingGC(*scriptCountsMap, [this](const auto& entry) {
      BaseScript* script = entry.key();
      CheckGCThingAfterMovingGC(script, this);
      return script;
    });
  }

  if (scriptLCovMap) {
    CheckTableAfterMovingGC(*scriptLCovMap, [this](const auto& entry) {
      BaseScript* script = entry.key();
      CheckGCThingAfterMovingGC(script, this);
      return script;
    });
  }

#  ifdef MOZ_VTUNE
  if (scriptVTuneIdMap) {
    CheckTableAfterMovingGC(*scriptVTuneIdMap, [this](const auto& entry) {
      BaseScript* script = entry.key();
      CheckGCThingAfterMovingGC(script, this);
      return script;
    });
  }
#  endif  // MOZ_VTUNE

#  ifdef JS_CACHEIR_SPEW
  if (scriptFinalWarmUpCountMap) {
    CheckTableAfterMovingGC(*scriptFinalWarmUpCountMap,
                            [this](const auto& entry) {
                              BaseScript* script = entry.key();
                              CheckGCThingAfterMovingGC(script, this);
                              return script;
                            });
  }
#  endif  // JS_CACHEIR_SPEW
}
#endif

void Zone::clearScriptCounts(Realm* realm) {
  if (!scriptCountsMap) {
    return;
  }

  // Clear all hasScriptCounts_ flags of BaseScript, in order to release all
  // ScriptCounts entries of the given realm.
  for (auto i = scriptCountsMap->modIter(); !i.done(); i.next()) {
    BaseScript* script = i.get().key();
    if (script->realm() != realm) {
      continue;
    }
    // We can't destroy the ScriptCounts yet if the script has Baseline code,
    // because Baseline code bakes in pointers to the counters. The ScriptCounts
    // will be destroyed in Zone::discardJitCode when discarding the JitScript.
    if (script->hasBaselineScript()) {
      continue;
    }
    script->clearHasScriptCounts();
    i.remove();
  }
}

void Zone::clearScriptLCov(Realm* realm) {
  if (!scriptLCovMap) {
    return;
  }

  for (auto i = scriptLCovMap->modIter(); !i.done(); i.next()) {
    BaseScript* script = i.get().key();
    if (script->realm() == realm) {
      i.remove();
    }
  }
}

void Zone::clearRootsForShutdownGC() {
  // Finalization callbacks are not called if we're shutting down.
  if (finalizationObservers()) {
    finalizationObservers()->clearRecords();
  }

  clearKeptObjects();
}

void Zone::finishRoots() {
  for (RealmsInZoneIter r(this); !r.done(); r.next()) {
    r->finishRoots();
  }
}

void Zone::traceKeptObjects(JSTracer* trc) { keptObjects.ref().trace(trc); }

bool Zone::addToKeptObjects(HandleObject target) {
  return keptObjects.ref().put(target);
}

void Zone::clearKeptObjects() { keptObjects.ref().clear(); }

bool Zone::ensureFinalizationObservers() {
  if (finalizationObservers_.ref()) {
    return true;
  }

  finalizationObservers_ = js::MakeUnique<FinalizationObservers>(this);
  return bool(finalizationObservers_.ref());
}

bool Zone::registerObjectWithWeakPointers(JSObject* obj) {
  MOZ_ASSERT(obj->getClass()->hasTrace());
  MOZ_ASSERT(!IsInsideNursery(obj));
  return objectsWithWeakPointers.ref().append(obj);
}