[heap] Rename safepoint scopes

This CL simplifies safepoint scopes, there are now three kinds of
safepoint scopes:

1) IsolateSafepointScope - performs an isolate local safepoint
2) GlobalSafepointScope - a global safepoint across multiple isolates
3) SafepointScope - chooses based on condition between local/global

This CL is not supposed to change current safepointing behavior in
any way. The CL renames the current SafepointScope to
IsolateSafepointScope and changes GlobalSafepointScope to always
perform a global safepoint. It then also introduces the new
SafepointScope and makes use of it for snapshotting and in heap.cc.

Bug: v8:13267
Change-Id: Ie7e1f81b6158c98d3d98552ba735cc73c9b869c5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3973310
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83912}

src/api/api.cc

@@ -617,7 +617,10 @@ StartupData SnapshotCreator::CreateBlob(
   i::Snapshot::ClearReconstructableDataForSerialization(
       i_isolate, function_code_handling == FunctionCodeHandling::kClear);
 
-  i::GlobalSafepointScope global_safepoint(i_isolate);
+  i::SafepointKind safepoint_kind = i_isolate->has_shared_heap()
+                                        ? i::SafepointKind::kGlobal
+                                        : i::SafepointKind::kIsolate;
+  i::SafepointScope safepoint_scope(i_isolate, safepoint_kind);
   i::DisallowGarbageCollection no_gc_from_here_on;
 
   // Create a vector with all contexts and clear associated Persistent fields.
@@ -655,7 +658,7 @@ StartupData SnapshotCreator::CreateBlob(
 
   data->created_ = true;
   return i::Snapshot::Create(i_isolate, &contexts, embedder_fields_serializers,
-                             global_safepoint, no_gc_from_here_on);
+                             safepoint_scope, no_gc_from_here_on);
 }
 
 bool StartupData::CanBeRehashed() const {

src/heap/combined-heap.h

@@ -26,7 +26,7 @@ class V8_EXPORT_PRIVATE CombinedHeapObjectIterator final {
   HeapObject Next();
 
  private:
-  SafepointScope safepoint_scope_;
+  IsolateSafepointScope safepoint_scope_;
   HeapObjectIterator heap_iterator_;
   ReadOnlyHeapObjectIterator ro_heap_iterator_;
 };

src/heap/heap-verifier.cc

@@ -73,7 +73,7 @@ void HeapVerification::Verify() {
   CHECK(heap()->HasBeenSetUp());
   AllowGarbageCollection allow_gc;
   IgnoreLocalGCRequests ignore_gc_requests(heap());
-  SafepointScope safepoint_scope(heap());
+  IsolateSafepointScope safepoint_scope(heap());
   HandleScope scope(isolate());
 
   heap()->MakeHeapIterable();

src/heap/heap.cc

@@ -1841,18 +1841,16 @@ void Heap::StartIncrementalMarking(int gc_flags,
     CompleteSweepingFull();
   }
 
-  base::Optional<GlobalSafepointScope> global_safepoint_scope;
   base::Optional<SafepointScope> safepoint_scope;
 
   {
     AllowGarbageCollection allow_shared_gc;
     IgnoreLocalGCRequests ignore_gc_requests(this);
 
-    if (isolate()->is_shared_heap_isolate()) {
-      global_safepoint_scope.emplace(isolate());
-    } else {
-      safepoint_scope.emplace(this);
-    }
+    SafepointKind safepoint_kind = isolate()->is_shared_heap_isolate()
+                                       ? SafepointKind::kGlobal
+                                       : SafepointKind::kIsolate;
+    safepoint_scope.emplace(isolate(), safepoint_kind);
   }
 
 #ifdef DEBUG
@@ -2165,18 +2163,17 @@ size_t Heap::PerformGarbageCollection(
   DCHECK(tracer()->IsConsistentWithCollector(collector));
   TRACE_GC_EPOCH(tracer(), CollectorScopeId(collector), ThreadKind::kMain);
 
-  base::Optional<GlobalSafepointScope> global_safepoint_scope;
-  base::Optional<SafepointScope> isolate_safepoint_scope;
+  base::Optional<SafepointScope> safepoint_scope;
 
   {
     AllowGarbageCollection allow_shared_gc;
     IgnoreLocalGCRequests ignore_gc_requests(this);
 
-    if (isolate()->is_shared_heap_isolate()) {
-      global_safepoint_scope.emplace(isolate());
-    } else {
-      isolate_safepoint_scope.emplace(this);
-    }
+    SafepointKind safepoint_kind =
+        v8_flags.shared_space && isolate()->is_shared_heap_isolate()
+            ? SafepointKind::kGlobal
+            : SafepointKind::kIsolate;
+    safepoint_scope.emplace(isolate(), safepoint_kind);
   }
 
   collection_barrier_->StopTimeToCollectionTimer();
@@ -3433,7 +3430,7 @@ FixedArrayBase Heap::LeftTrimFixedArray(FixedArrayBase object,
   if (v8_flags.enable_slow_asserts) {
     // Make sure the stack or other roots (e.g., Handles) don't contain pointers
     // to the original FixedArray (which is now the filler object).
-    base::Optional<SafepointScope> safepoint_scope;
+    base::Optional<IsolateSafepointScope> safepoint_scope;
 
     {
       AllowGarbageCollection allow_gc;
@@ -4201,7 +4198,7 @@ std::unique_ptr<v8::MeasureMemoryDelegate> Heap::MeasureMemoryDelegate(
 void Heap::CollectCodeStatistics() {
   TRACE_EVENT0("v8", "Heap::CollectCodeStatistics");
   IgnoreLocalGCRequests ignore_gc_requests(this);
-  SafepointScope safepoint_scope(this);
+  IsolateSafepointScope safepoint_scope(this);
   MakeHeapIterable();
   CodeStatistics::ResetCodeAndMetadataStatistics(isolate());
   // We do not look for code in new space, or map space.  If code
@@ -6401,7 +6398,7 @@ class UnreachableObjectsFilter : public HeapObjectsFilter {
 HeapObjectIterator::HeapObjectIterator(
     Heap* heap, HeapObjectIterator::HeapObjectsFiltering filtering)
     : heap_(heap),
-      safepoint_scope_(std::make_unique<SafepointScope>(heap)),
+      safepoint_scope_(std::make_unique<IsolateSafepointScope>(heap)),
       filtering_(filtering),
       filter_(nullptr),
       space_iterator_(nullptr),

src/heap/heap.h

@@ -105,6 +105,7 @@ class HeapObjectAllocationTracker;
 class HeapObjectsFilter;
 class HeapStats;
 class Isolate;
+class IsolateSafepointScope;
 class JSFinalizationRegistry;
 class LinearAllocationArea;
 class LocalEmbedderHeapTracer;
@@ -123,7 +124,6 @@ class PagedNewSpace;
 class ReadOnlyHeap;
 class RootVisitor;
 class RwxMemoryWriteScope;
-class SafepointScope;
 class ScavengeJob;
 class Scavenger;
 class ScavengerCollector;
@@ -2751,7 +2751,7 @@ class V8_EXPORT_PRIVATE HeapObjectIterator {
   HeapObject NextObject();
 
   Heap* heap_;
-  std::unique_ptr<SafepointScope> safepoint_scope_;
+  std::unique_ptr<IsolateSafepointScope> safepoint_scope_;
   HeapObjectsFiltering filtering_;
   HeapObjectsFilter* filter_;
   // Space iterator for iterating all the spaces.

src/heap/local-heap.h

@@ -335,11 +335,11 @@ class V8_EXPORT_PRIVATE LocalHeap {
   friend class CollectionBarrier;
   friend class ConcurrentAllocator;
   friend class GlobalSafepoint;
-  friend class IsolateSafepoint;
   friend class Heap;
   friend class Isolate;
+  friend class IsolateSafepoint;
+  friend class IsolateSafepointScope;
   friend class ParkedScope;
-  friend class SafepointScope;
   friend class UnparkedScope;
 };
 

src/heap/safepoint.cc

@@ -282,11 +282,14 @@ Isolate* IsolateSafepoint::shared_heap_isolate() const {
   return isolate()->shared_heap_isolate();
 }
 
-SafepointScope::SafepointScope(Heap* heap) : safepoint_(heap->safepoint()) {
+IsolateSafepointScope::IsolateSafepointScope(Heap* heap)
+    : safepoint_(heap->safepoint()) {
   safepoint_->EnterLocalSafepointScope();
 }
 
-SafepointScope::~SafepointScope() { safepoint_->LeaveLocalSafepointScope(); }
+IsolateSafepointScope::~IsolateSafepointScope() {
+  safepoint_->LeaveLocalSafepointScope();
+}
 
 GlobalSafepoint::GlobalSafepoint(Isolate* isolate)
     : shared_heap_isolate_(isolate) {}
@@ -415,23 +418,22 @@ void GlobalSafepoint::LeaveGlobalSafepointScope(Isolate* initiator) {
 
 GlobalSafepointScope::GlobalSafepointScope(Isolate* initiator)
     : initiator_(initiator),
-      shared_heap_isolate_(initiator->has_shared_heap()
-                               ? initiator->shared_heap_isolate()
-                               : nullptr) {
-  if (shared_heap_isolate_) {
+      shared_heap_isolate_(initiator->shared_heap_isolate()) {
   shared_heap_isolate_->global_safepoint()->EnterGlobalSafepointScope(
       initiator_);
-  } else {
-    initiator_->heap()->safepoint()->EnterLocalSafepointScope();
-  }
 }
 
 GlobalSafepointScope::~GlobalSafepointScope() {
-  if (shared_heap_isolate_) {
   shared_heap_isolate_->global_safepoint()->LeaveGlobalSafepointScope(
       initiator_);
+}
+
+SafepointScope::SafepointScope(Isolate* initiator, SafepointKind kind) {
+  if (kind == SafepointKind::kIsolate) {
+    isolate_safepoint_.emplace(initiator->heap());
   } else {
-    initiator_->heap()->safepoint()->LeaveLocalSafepointScope();
+    DCHECK_EQ(kind, SafepointKind::kGlobal);
+    global_safepoint_.emplace(initiator);
   }
 }
 

src/heap/safepoint.h

@@ -148,14 +148,14 @@ class IsolateSafepoint final {
   friend class GlobalSafepoint;
   friend class GlobalSafepointScope;
   friend class Isolate;
+  friend class IsolateSafepointScope;
   friend class LocalHeap;
-  friend class SafepointScope;
 };
 
-class V8_NODISCARD SafepointScope {
+class V8_NODISCARD IsolateSafepointScope {
  public:
-  V8_EXPORT_PRIVATE explicit SafepointScope(Heap* heap);
-  V8_EXPORT_PRIVATE ~SafepointScope();
+  V8_EXPORT_PRIVATE explicit IsolateSafepointScope(Heap* heap);
+  V8_EXPORT_PRIVATE ~IsolateSafepointScope();
 
  private:
   IsolateSafepoint* safepoint_;
@@ -204,6 +204,18 @@ class V8_NODISCARD GlobalSafepointScope {
   Isolate* const shared_heap_isolate_;
 };
 
+enum class SafepointKind { kIsolate, kGlobal };
+
+class V8_NODISCARD SafepointScope {
+ public:
+  V8_EXPORT_PRIVATE explicit SafepointScope(Isolate* initiator,
+                                            SafepointKind kind);
+
+ private:
+  base::Optional<IsolateSafepointScope> isolate_safepoint_;
+  base::Optional<GlobalSafepointScope> global_safepoint_;
+};
+
 }  // namespace internal
 }  // namespace v8
 

src/profiler/heap-snapshot-generator.cc

@@ -2463,7 +2463,7 @@ void V8HeapExplorer::CollectGlobalObjectsTags() {
 }
 
 void V8HeapExplorer::MakeGlobalObjectTagMap(
-    const SafepointScope& safepoint_scope) {
+    const IsolateSafepointScope& safepoint_scope) {
   for (const auto& pair : global_object_tag_pairs_) {
     global_object_tag_map_.emplace(*pair.first, pair.second);
   }
@@ -2723,7 +2723,7 @@ bool HeapSnapshotGenerator::GenerateSnapshot() {
   heap_->CollectAllAvailableGarbage(GarbageCollectionReason::kHeapProfiler);
 
   NullContextForSnapshotScope null_context_scope(isolate);
-  SafepointScope scope(heap_);
+  IsolateSafepointScope scope(heap_);
   v8_heap_explorer_.MakeGlobalObjectTagMap(scope);
   handle_scope.reset();
 

src/profiler/heap-snapshot-generator.h

@@ -36,6 +36,7 @@ class HeapEntry;
 class HeapProfiler;
 class HeapSnapshot;
 class HeapSnapshotGenerator;
+class IsolateSafepointScope;
 class JSArrayBuffer;
 class JSCollection;
 class JSGeneratorObject;
@@ -43,7 +44,6 @@ class JSGlobalObject;
 class JSGlobalProxy;
 class JSPromise;
 class JSWeakCollection;
-class SafepointScope;
 
 struct SourceLocation {
   SourceLocation(int entry_index, int scriptId, int line, int col)
@@ -390,7 +390,7 @@ class V8_EXPORT_PRIVATE V8HeapExplorer : public HeapEntriesAllocator {
   uint32_t EstimateObjectsCount();
   bool IterateAndExtractReferences(HeapSnapshotGenerator* generator);
   void CollectGlobalObjectsTags();
-  void MakeGlobalObjectTagMap(const SafepointScope& safepoint_scope);
+  void MakeGlobalObjectTagMap(const IsolateSafepointScope& safepoint_scope);
   void TagBuiltinCodeObject(CodeT code, const char* name);
   HeapEntry* AddEntry(Address address,
                       HeapEntry::Type type,

src/snapshot/snapshot.cc

@@ -315,7 +315,10 @@ void Snapshot::SerializeDeserializeAndVerifyForTesting(
 
   // Test serialization.
   {
-    GlobalSafepointScope global_safepoint(isolate);
+    SafepointKind safepoint_kind = isolate->has_shared_heap()
+                                       ? SafepointKind::kGlobal
+                                       : SafepointKind::kIsolate;
+    SafepointScope safepoint_scope(isolate, safepoint_kind);
     DisallowGarbageCollection no_gc;
 
     Snapshot::SerializerFlags flags(
@@ -325,7 +328,7 @@ void Snapshot::SerializeDeserializeAndVerifyForTesting(
              ? Snapshot::kReconstructReadOnlyAndSharedObjectCachesForTesting
              : 0));
     serialized_data = Snapshot::Create(isolate, *default_context,
-                                       global_safepoint, no_gc, flags);
+                                       safepoint_scope, no_gc, flags);
     auto_delete_serialized_data.reset(serialized_data.data);
   }
 
@@ -369,14 +372,14 @@ v8::StartupData Snapshot::Create(
     Isolate* isolate, std::vector<Context>* contexts,
     const std::vector<SerializeInternalFieldsCallback>&
         embedder_fields_serializers,
-    const GlobalSafepointScope& global_safepoint,
+    const SafepointScope& safepoint_scope,
     const DisallowGarbageCollection& no_gc, SerializerFlags flags) {
   TRACE_EVENT0("v8", "V8.SnapshotCreate");
   DCHECK_EQ(contexts->size(), embedder_fields_serializers.size());
   DCHECK_GT(contexts->size(), 0);
   HandleScope scope(isolate);
 
-  // The GlobalSafepointScope ensures we are in a safepoint scope so that the
+  // The HeapSafepointScope ensures we are in a safepoint scope so that the
   // string table is safe to iterate. Unlike mksnapshot, embedders may have
   // background threads running.
 
@@ -453,13 +456,13 @@ v8::StartupData Snapshot::Create(
 
 // static
 v8::StartupData Snapshot::Create(Isolate* isolate, Context default_context,
-                                 const GlobalSafepointScope& global_safepoint,
+                                 const SafepointScope& safepoint_scope,
                                  const DisallowGarbageCollection& no_gc,
                                  SerializerFlags flags) {
   std::vector<Context> contexts{default_context};
   std::vector<SerializeInternalFieldsCallback> callbacks{{}};
-  return Snapshot::Create(isolate, &contexts, callbacks, global_safepoint,
-                          no_gc, flags);
+  return Snapshot::Create(isolate, &contexts, callbacks, safepoint_scope, no_gc,
+                          flags);
 }
 
 v8::StartupData SnapshotImpl::CreateSnapshotBlob(

src/snapshot/snapshot.h

@@ -15,10 +15,10 @@ namespace v8 {
 namespace internal {
 
 class Context;
-class GlobalSafepointScope;
 class Isolate;
-class SnapshotData;
 class JSGlobalProxy;
+class SafepointScope;
+class SnapshotData;
 
 class Snapshot : public AllStatic {
  public:
@@ -69,14 +69,14 @@ class Snapshot : public AllStatic {
       Isolate* isolate, std::vector<Context>* contexts,
       const std::vector<SerializeInternalFieldsCallback>&
           embedder_fields_serializers,
-      const GlobalSafepointScope& global_safepoint,
+      const SafepointScope& safepoint_scope,
       const DisallowGarbageCollection& no_gc,
       SerializerFlags flags = kDefaultSerializerFlags);
 
   // Convenience helper for the above when only serializing a single context.
   static v8::StartupData Create(
       Isolate* isolate, Context default_context,
-      const GlobalSafepointScope& global_safepoint,
+      const SafepointScope& safepoint_scope,
       const DisallowGarbageCollection& no_gc,
       SerializerFlags flags = kDefaultSerializerFlags);
 

test/cctest/heap/heap-utils.cc

@@ -263,7 +263,7 @@ void SimulateIncrementalMarking(i::Heap* heap, bool force_completion) {
   i::IncrementalMarking* marking = heap->incremental_marking();
 
   if (heap->sweeping_in_progress()) {
-    SafepointScope scope(heap);
+    IsolateSafepointScope scope(heap);
     heap->EnsureSweepingCompleted(
         Heap::SweepingForcedFinalizationMode::kV8Only);
   }
@@ -282,7 +282,7 @@ void SimulateIncrementalMarking(i::Heap* heap, bool force_completion) {
   CHECK(marking->IsMarking());
   if (!force_completion) return;
 
-  SafepointScope scope(heap);
+  IsolateSafepointScope scope(heap);
   MarkingBarrier::PublishAll(heap);
   marking->MarkRootsForTesting();
 
@@ -315,7 +315,7 @@ void AbandonCurrentlyFreeMemory(PagedSpace* space) {
 void GcAndSweep(Heap* heap, AllocationSpace space) {
   heap->CollectGarbage(space, GarbageCollectionReason::kTesting);
   if (heap->sweeping_in_progress()) {
-    SafepointScope scope(heap);
+    IsolateSafepointScope scope(heap);
     heap->EnsureSweepingCompleted(
         Heap::SweepingForcedFinalizationMode::kV8Only);
   }
@@ -343,14 +343,14 @@ bool InCorrectGeneration(HeapObject object) {
 }
 
 void GrowNewSpace(Heap* heap) {
-  SafepointScope scope(heap);
+  IsolateSafepointScope scope(heap);
   if (!heap->new_space()->IsAtMaximumCapacity()) {
     heap->new_space()->Grow();
   }
 }
 
 void GrowNewSpaceToMaximumCapacity(Heap* heap) {
-  SafepointScope scope(heap);
+  IsolateSafepointScope scope(heap);
   while (!heap->new_space()->IsAtMaximumCapacity()) {
     heap->new_space()->Grow();
   }

test/cctest/heap/test-heap.cc

@@ -5860,7 +5860,7 @@ TEST(Regress598319) {
     }
   }
 
-  SafepointScope safepoint_scope(heap);
+  IsolateSafepointScope safepoint_scope(heap);
   MarkingBarrier::PublishAll(heap);
 
   // Finish marking with bigger steps to speed up test.
@@ -6566,7 +6566,7 @@ HEAP_TEST(Regress670675) {
   heap->tracer()->StopFullCycleIfNeeded();
   i::IncrementalMarking* marking = CcTest::heap()->incremental_marking();
   if (marking->IsStopped()) {
-    SafepointScope safepoint_scope(heap);
+    IsolateSafepointScope safepoint_scope(heap);
     heap->tracer()->StartCycle(
         GarbageCollector::MARK_COMPACTOR, GarbageCollectionReason::kTesting,
         "collector cctest", GCTracer::MarkingType::kIncremental);

test/cctest/heap/test-incremental-marking.cc

@@ -118,7 +118,7 @@ TEST_WITH_PLATFORM(IncrementalMarkingUsingTasks, MockPlatform) {
     i::IncrementalMarking* marking = heap->incremental_marking();
     marking->Stop();
     {
-      SafepointScope scope(heap);
+      IsolateSafepointScope scope(heap);
       heap->tracer()->StartCycle(
           GarbageCollector::MARK_COMPACTOR, GarbageCollectionReason::kTesting,
           "collector cctest", GCTracer::MarkingType::kIncremental);

test/cctest/heap/test-spaces.cc

@@ -161,7 +161,7 @@ static unsigned int PseudorandomAreaSize() {
 TEST(MemoryChunk) {
   Isolate* isolate = CcTest::i_isolate();
   Heap* heap = isolate->heap();
-  SafepointScope safepoint(heap);
+  IsolateSafepointScope safepoint(heap);
 
   v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t area_size;

test/cctest/test-serialize.cc

@@ -210,7 +210,7 @@ static StartupBlobs Serialize(v8::Isolate* isolate) {
   Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
   CcTest::CollectAllAvailableGarbage(i_isolate);
 
-  SafepointScope safepoint(i_isolate->heap());
+  IsolateSafepointScope safepoint(i_isolate->heap());
   HandleScope scope(i_isolate);
 
   DisallowGarbageCollection no_gc;
@@ -403,7 +403,7 @@ static void SerializeContext(base::Vector<const byte>* startup_blob_out,
 
     env.Reset();
 
-    SafepointScope safepoint(heap);
+    IsolateSafepointScope safepoint(heap);
 
     DisallowGarbageCollection no_gc;
     SnapshotByteSink read_only_sink;
@@ -572,7 +572,7 @@ static void SerializeCustomContext(
 
     env.Reset();
 
-    SafepointScope safepoint(isolate->heap());
+    IsolateSafepointScope safepoint(isolate->heap());
 
     DisallowGarbageCollection no_gc;
     SnapshotByteSink read_only_sink;

test/mkgrokdump/mkgrokdump.cc

@@ -127,7 +127,7 @@ static int DumpHeapConstants(FILE* out, const char* argv0) {
   {
     Isolate::Scope scope(isolate);
     i::Heap* heap = reinterpret_cast<i::Isolate*>(isolate)->heap();
-    i::SafepointScope safepoint_scope(heap);
+    i::IsolateSafepointScope safepoint_scope(heap);
     i::ReadOnlyHeap* read_only_heap =
         reinterpret_cast<i::Isolate*>(isolate)->read_only_heap();
     i::PrintF(out, "%s", kHeader);

test/unittests/heap/embedder-tracing-unittest.cc

@@ -466,7 +466,7 @@ TEST_F(EmbedderTracingTest, FinalizeTracingWhenMarking) {
 
   i::IncrementalMarking* marking = heap->incremental_marking();
   {
-    SafepointScope scope(heap);
+    IsolateSafepointScope scope(heap);
     heap->tracer()->StartCycle(
         GarbageCollector::MARK_COMPACTOR, GarbageCollectionReason::kTesting,
         "collector cctest", GCTracer::MarkingType::kIncremental);

test/unittests/heap/heap-unittest.cc

@@ -162,7 +162,7 @@ TEST_F(HeapTest, HeapLayout) {
   base::AddressRegion heap_reservation(cage_base, size_t{4} * GB);
   base::AddressRegion code_reservation(code_cage_base, size_t{4} * GB);
 
-  SafepointScope scope(i_isolate()->heap());
+  IsolateSafepointScope scope(i_isolate()->heap());
   OldGenerationMemoryChunkIterator iter(i_isolate()->heap());
   for (;;) {
     MemoryChunk* chunk = iter.next();
@@ -373,7 +373,7 @@ TEST_F(HeapTest, RememberedSet_InsertOnPromotingObjectToOld) {
     CHECK(!new_space->IsAtMaximumCapacity());
     // Fill current pages to force MinorMC to promote them.
     SimulateFullSpace(new_space, &handles);
-    SafepointScope scope(heap);
+    IsolateSafepointScope scope(heap);
     // New empty pages should remain in new space.
     new_space->Grow();
   } else {
@@ -422,7 +422,7 @@ TEST_F(HeapTest, Regress978156) {
   // 5. Start incremental marking.
   i::IncrementalMarking* marking = heap->incremental_marking();
   if (marking->IsStopped()) {
-    SafepointScope scope(heap);
+    IsolateSafepointScope scope(heap);
     heap->tracer()->StartCycle(
         GarbageCollector::MARK_COMPACTOR, GarbageCollectionReason::kTesting,
         "collector cctest", GCTracer::MarkingType::kIncremental);

test/unittests/heap/heap-utils.cc

@@ -24,7 +24,7 @@ void HeapInternalsBase::SimulateIncrementalMarking(Heap* heap,
   i::IncrementalMarking* marking = heap->incremental_marking();
 
   if (heap->sweeping_in_progress()) {
-    SafepointScope scope(heap);
+    IsolateSafepointScope scope(heap);
     heap->EnsureSweepingCompleted(
         Heap::SweepingForcedFinalizationMode::kV8Only);
   }

test/unittests/heap/heap-utils.h

@@ -65,7 +65,7 @@ class WithHeapInternals : public TMixin, HeapInternalsBase {
   }
 
   void GrowNewSpace() {
-    SafepointScope scope(heap());
+    IsolateSafepointScope scope(heap());
     if (!heap()->new_space()->IsAtMaximumCapacity()) {
       heap()->new_space()->Grow();
     }
@@ -89,7 +89,7 @@ class WithHeapInternals : public TMixin, HeapInternalsBase {
   void GcAndSweep(i::AllocationSpace space) {
     heap()->CollectGarbage(space, GarbageCollectionReason::kTesting);
     if (heap()->sweeping_in_progress()) {
-      SafepointScope scope(heap());
+      IsolateSafepointScope scope(heap());
       heap()->EnsureSweepingCompleted(
           Heap::SweepingForcedFinalizationMode::kV8Only);
     }

test/unittests/heap/marking-inner-pointer-resolution-unittest.cc

@@ -680,7 +680,7 @@ TEST_F(InnerPointerResolutionHeapTest, UnusedRegularYoungPages) {
     // Start incremental marking and mark the third object.
     i::IncrementalMarking* marking = heap()->incremental_marking();
     if (marking->IsStopped()) {
-      SafepointScope scope(heap());
+      IsolateSafepointScope scope(heap());
       heap()->tracer()->StartCycle(
           GarbageCollector::MARK_COMPACTOR, GarbageCollectionReason::kTesting,
           "unit test", GCTracer::MarkingType::kIncremental);

test/unittests/heap/safepoint-unittest.cc

@@ -21,7 +21,7 @@ TEST_F(SafepointTest, ReachSafepointWithoutLocalHeaps) {
   Heap* heap = i_isolate()->heap();
   bool run = false;
   {
-    SafepointScope scope(heap);
+    IsolateSafepointScope scope(heap);
     run = true;
   }
   CHECK(run);
@@ -68,7 +68,7 @@ TEST_F(SafepointTest, StopParkedThreads) {
     }
 
     {
-      SafepointScope scope(heap);
+      IsolateSafepointScope scope(heap);
       safepoints++;
     }
     mutex.Unlock();
@@ -124,7 +124,7 @@ TEST_F(SafepointTest, StopRunningThreads) {
     }
 
     for (int i = 0; i < kSafepoints; i++) {
-      SafepointScope scope(heap);
+      IsolateSafepointScope scope(heap);
       safepoint_count++;
     }