[heap] Remove independent handles

Removes the handling of the flag independent. The flag will be removed in a followup. The patch changes handling of V8::PersistentBase that are set to Weak: - The Scavenger ignores the flag independent. - The Scavenger keeps alive anything that is marked as Active. - The Scavenger is free to drop weak handles of non-Active object if they are otherwise dead. Active: - Any JSObject will always be marked Active. - Any JSApiObject will be marked Active if it has been modified (=has elements, properties, etc.) CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel Bug: chromium:780749 Change-Id: If1f547f2419930ad9400bd3b11bdbf609cb57649 Reviewed-on: https://chromium-review.googlesource.com/741801 Commit-Queue: Michael Lippautz <mlippautz@chromium.org> Reviewed-by: Kentaro Hara <haraken@chromium.org> Reviewed-by: Hannes Payer <hpayer@chromium.org> Reviewed-by: Ulan Degenbaev <ulan@chromium.org> Cr-Commit-Position: refs/heads/master@{#49277}
2017-11-09 17:27:34 +01:00 · 2017-11-09 17:27:34 +01:00 · 667555c6b8
commit 667555c6b8
parent ff4e4ab4b6
5 changed files with 270 additions and 246 deletions
--- a/src/global-handles.cc
+++ b/src/global-handles.cc
@ -665,8 +665,7 @@ void GlobalHandles::IdentifyWeakHandles(WeakSlotCallback should_reset_handle) {
 void GlobalHandles::IterateNewSpaceStrongAndDependentRoots(RootVisitor* v) {
  for (Node* node : new_space_nodes_) {
    if (node->IsStrongRetainer() ||
-        (node->IsWeakRetainer() && !node->is_independent() &&
-         node->is_active())) {
+        (node->IsWeakRetainer() && node->is_active())) {
      v->VisitRootPointer(Root::kGlobalHandles, node->location());
    }
  }
@ -680,8 +679,7 @@ void GlobalHandles::IterateNewSpaceStrongAndDependentRootsAndIdentifyUnmodified(
      node->set_active(true);
    }
    if (node->IsStrongRetainer() ||
-        (node->IsWeakRetainer() && !node->is_independent() &&
-         node->is_active())) {
+        (node->IsWeakRetainer() && node->is_active())) {
      v->VisitRootPointer(Root::kGlobalHandles, node->location());
    }
  }
@ -696,13 +694,12 @@ void GlobalHandles::IdentifyWeakUnmodifiedObjects(
  }
 }

-
 void GlobalHandles::MarkNewSpaceWeakUnmodifiedObjectsPending(
-    WeakSlotCallbackWithHeap is_unscavenged) {
+    WeakSlotCallbackWithHeap is_dead) {
  for (Node* node : new_space_nodes_) {
    DCHECK(node->is_in_new_space_list());
-    if ((node->is_independent() || !node->is_active()) && node->IsWeak() &&
-        is_unscavenged(isolate_->heap(), node->location())) {
+    if (node->IsWeak() && is_dead(isolate_->heap(), node->location())) {
+      DCHECK(!node->is_active());
      if (!node->IsPhantomCallback() && !node->IsPhantomResetHandle()) {
        node->MarkPending();
      }
@ -714,8 +711,8 @@ void GlobalHandles::IterateNewSpaceWeakUnmodifiedRootsForFinalizers(
    RootVisitor* v) {
  for (Node* node : new_space_nodes_) {
    DCHECK(node->is_in_new_space_list());
-    if ((node->is_independent() || !node->is_active()) &&
-        node->IsWeakRetainer() && (node->state() == Node::PENDING)) {
+    if (!node->is_active() && node->IsWeakRetainer() &&
+        (node->state() == Node::PENDING)) {
      DCHECK(!node->IsPhantomCallback());
      DCHECK(!node->IsPhantomResetHandle());
      // Finalizers need to survive.
@ -728,8 +725,8 @@ void GlobalHandles::IterateNewSpaceWeakUnmodifiedRootsForPhantomHandles(
    RootVisitor* v, WeakSlotCallbackWithHeap should_reset_handle) {
  for (Node* node : new_space_nodes_) {
    DCHECK(node->is_in_new_space_list());
-    if ((node->is_independent() || !node->is_active()) &&
-        node->IsWeakRetainer() && (node->state() != Node::PENDING)) {
+    if (!node->is_active() && node->IsWeakRetainer() &&
+        (node->state() != Node::PENDING)) {
      DCHECK(node->IsPhantomResetHandle() || node->IsPhantomCallback());
      if (should_reset_handle(isolate_->heap(), node->location())) {
        if (node->IsPhantomResetHandle()) {
@ -774,15 +771,12 @@ int GlobalHandles::PostScavengeProcessing(
      // the freed_nodes.
      continue;
    }
-    // Skip dependent or unmodified handles. Their weak callbacks might expect
-    // to be
-    // called between two global garbage collection callbacks which
-    // are not called for minor collections.
-      if (!node->is_independent() && (node->is_active())) {
-        node->set_active(false);
-        continue;
-      }
+
+    // Active nodes are kept alive, so no further processing is requires.
+    if (node->is_active()) {
      node->set_active(false);
+      continue;
+    }

    if (node->PostGarbageCollectionProcessing(isolate_)) {
      if (initial_post_gc_processing_count != post_gc_processing_count_) {
@ -793,6 +787,7 @@ int GlobalHandles::PostScavengeProcessing(
        return freed_nodes;
      }
    }
+
    if (!node->IsRetainer()) {
      freed_nodes++;
    }
--- a/src/global-handles.h
+++ b/src/global-handles.h
@ -154,10 +154,9 @@ class GlobalHandles {
  void IterateNewSpaceStrongAndDependentRootsAndIdentifyUnmodified(
      RootVisitor* v, size_t start, size_t end);

-  // Finds weak independent or unmodified handles satisfying
-  // the callback predicate and marks them as pending. See the note above.
+  // Marks weak unmodified handles satisfying |is_dead| as pending.
  void MarkNewSpaceWeakUnmodifiedObjectsPending(
-      WeakSlotCallbackWithHeap is_unscavenged);
+      WeakSlotCallbackWithHeap is_dead);

  // Iterates over weak independent or unmodified handles.
  // See the note above.
--- a/src/profiler/sampling-heap-profiler.cc
+++ b/src/profiler/sampling-heap-profiler.cc
@ -112,7 +112,6 @@ void SamplingHeapProfiler::SampleObject(Address soon_object, size_t size) {
  Sample* sample = new Sample(size, node, loc, this);
  samples_.insert(sample);
  sample->global.SetWeak(sample, OnWeakCallback, WeakCallbackType::kParameter);
-  sample->global.MarkIndependent();
 }

 void SamplingHeapProfiler::OnWeakCallback(
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@ -7659,84 +7659,6 @@ struct FlagAndPersistent {
  v8::Global<v8::Object> handle;
 };

-
-static void SetFlag(const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
-  data.GetParameter()->flag = true;
-  data.GetParameter()->handle.Reset();
-}
-
-
-static void IndependentWeakHandle(bool global_gc, bool interlinked) {
-  i::FLAG_stress_incremental_marking = false;
-  // Parallel scavenge introduces too much fragmentation.
-  i::FLAG_parallel_scavenge = false;
-  v8::Isolate* iso = CcTest::isolate();
-  v8::HandleScope scope(iso);
-  v8::Local<Context> context = Context::New(iso);
-  Context::Scope context_scope(context);
-
-  FlagAndPersistent object_a, object_b;
-
-  size_t big_heap_size = 0;
-  size_t big_array_size = 0;
-
-  {
-    v8::HandleScope handle_scope(iso);
-    Local<Object> a(v8::Object::New(iso));
-    Local<Object> b(v8::Object::New(iso));
-    object_a.handle.Reset(iso, a);
-    object_b.handle.Reset(iso, b);
-    if (interlinked) {
-      a->Set(context, v8_str("x"), b).FromJust();
-      b->Set(context, v8_str("x"), a).FromJust();
-    }
-    if (global_gc) {
-      CcTest::CollectAllGarbage();
-    } else {
-      CcTest::CollectGarbage(i::NEW_SPACE);
-    }
-    v8::Local<Value> big_array = v8::Array::New(CcTest::isolate(), 5000);
-    // Verify that we created an array where the space was reserved up front.
-    big_array_size =
-        v8::internal::JSArray::cast(*v8::Utils::OpenHandle(*big_array))
-            ->elements()
-            ->Size();
-    CHECK_LE(20000, big_array_size);
-    a->Set(context, v8_str("y"), big_array).FromJust();
-    big_heap_size = CcTest::heap()->SizeOfObjects();
-  }
-
-  object_a.flag = false;
-  object_b.flag = false;
-  object_a.handle.SetWeak(&object_a, &SetFlag,
-                          v8::WeakCallbackType::kParameter);
-  object_b.handle.SetWeak(&object_b, &SetFlag,
-                          v8::WeakCallbackType::kParameter);
-  CHECK(!object_b.handle.IsIndependent());
-  object_a.handle.MarkIndependent();
-  object_b.handle.MarkIndependent();
-  CHECK(object_b.handle.IsIndependent());
-  if (global_gc) {
-    CcTest::CollectAllGarbage();
-  } else {
-    CcTest::CollectGarbage(i::NEW_SPACE);
-  }
-  // A single GC should be enough to reclaim the memory, since we are using
-  // phantom handles.
-  CHECK_GT(big_heap_size - big_array_size, CcTest::heap()->SizeOfObjects());
-  CHECK(object_a.flag);
-  CHECK(object_b.flag);
-}
-
-
-TEST(IndependentWeakHandle) {
-  IndependentWeakHandle(false, false);
-  IndependentWeakHandle(false, true);
-  IndependentWeakHandle(true, false);
-  IndependentWeakHandle(true, true);
-}
-
-
 class Trivial {
 public:
  explicit Trivial(int x) : x_(x) {}
@ -7832,130 +7754,6 @@ THREADED_TEST(InternalFieldCallback) {
  InternalFieldCallback(true);
 }

-
-static void ResetUseValueAndSetFlag(
-    const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
-  // Blink will reset the handle, and then use the other handle, so they
-  // can't use the same backing slot.
-  data.GetParameter()->handle.Reset();
-  data.GetParameter()->flag = true;
-}
-
-void v8::internal::heap::HeapTester::ResetWeakHandle(bool global_gc) {
-  using v8::Context;
-  using v8::Local;
-  using v8::Object;
-
-  v8::Isolate* iso = CcTest::isolate();
-  v8::HandleScope scope(iso);
-  v8::Local<Context> context = Context::New(iso);
-  Context::Scope context_scope(context);
-
-  FlagAndPersistent object_a, object_b;
-
-  {
-    v8::HandleScope handle_scope(iso);
-    Local<Object> a(v8::Object::New(iso));
-    Local<Object> b(v8::Object::New(iso));
-    object_a.handle.Reset(iso, a);
-    object_b.handle.Reset(iso, b);
-    if (global_gc) {
-      CcTest::CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
-    } else {
-      CcTest::CollectGarbage(i::NEW_SPACE);
-    }
-  }
-
-  object_a.flag = false;
-  object_b.flag = false;
-  object_a.handle.SetWeak(&object_a, &ResetUseValueAndSetFlag,
-                          v8::WeakCallbackType::kParameter);
-  object_b.handle.SetWeak(&object_b, &ResetUseValueAndSetFlag,
-                          v8::WeakCallbackType::kParameter);
-  if (!global_gc) {
-    object_a.handle.MarkIndependent();
-    object_b.handle.MarkIndependent();
-    CHECK(object_b.handle.IsIndependent());
-  }
-  if (global_gc) {
-    CcTest::CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
-  } else {
-    CcTest::CollectGarbage(i::NEW_SPACE);
-  }
-  CHECK(object_a.flag);
-  CHECK(object_b.flag);
-}
-
-
-THREADED_HEAP_TEST(ResetWeakHandle) {
-  v8::internal::heap::HeapTester::ResetWeakHandle(false);
-  v8::internal::heap::HeapTester::ResetWeakHandle(true);
-}
-
-static void InvokeScavenge() { CcTest::CollectGarbage(i::NEW_SPACE); }
-
-static void InvokeMarkSweep() { CcTest::CollectAllGarbage(); }
-
-static void ForceScavenge2(
-    const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
-  data.GetParameter()->flag = true;
-  InvokeScavenge();
-}
-
-static void ForceScavenge1(
-    const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
-  data.GetParameter()->handle.Reset();
-  data.SetSecondPassCallback(ForceScavenge2);
-}
-
-
-static void ForceMarkSweep2(
-    const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
-  data.GetParameter()->flag = true;
-  InvokeMarkSweep();
-}
-
-static void ForceMarkSweep1(
-    const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
-  data.GetParameter()->handle.Reset();
-  data.SetSecondPassCallback(ForceMarkSweep2);
-}
-
-
-THREADED_TEST(GCFromWeakCallbacks) {
-  v8::Isolate* isolate = CcTest::isolate();
-  v8::Locker locker(CcTest::isolate());
-  v8::HandleScope scope(isolate);
-  v8::Local<Context> context = Context::New(isolate);
-  Context::Scope context_scope(context);
-
-  static const int kNumberOfGCTypes = 2;
-  typedef v8::WeakCallbackInfo<FlagAndPersistent>::Callback Callback;
-  Callback gc_forcing_callback[kNumberOfGCTypes] = {&ForceScavenge1,
-                                                    &ForceMarkSweep1};
-
-  typedef void (*GCInvoker)();
-  GCInvoker invoke_gc[kNumberOfGCTypes] = {&InvokeScavenge, &InvokeMarkSweep};
-
-  for (int outer_gc = 0; outer_gc < kNumberOfGCTypes; outer_gc++) {
-    for (int inner_gc = 0; inner_gc < kNumberOfGCTypes; inner_gc++) {
-      FlagAndPersistent object;
-      {
-        v8::HandleScope handle_scope(isolate);
-        object.handle.Reset(isolate, v8::Object::New(isolate));
-      }
-      object.flag = false;
-      object.handle.SetWeak(&object, gc_forcing_callback[inner_gc],
-                            v8::WeakCallbackType::kParameter);
-      object.handle.MarkIndependent();
-      invoke_gc[outer_gc]();
-      EmptyMessageQueues(isolate);
-      CHECK(object.flag);
-    }
-  }
-}
-
-
 v8::Local<Function> args_fun;


--- a/test/cctest/test-global-handles.cc
+++ b/test/cctest/test-global-handles.cc
@ -36,6 +36,97 @@
 namespace v8 {
 namespace internal {

+namespace {
+
+void SimpleCallback(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  info.GetReturnValue().Set(v8_num(0));
+}
+
+struct FlagAndPersistent {
+  bool flag;
+  v8::Global<v8::Object> handle;
+};
+
+void ResetHandleAndSetFlag(
+    const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
+  data.GetParameter()->handle.Reset();
+  data.GetParameter()->flag = true;
+}
+
+using ConstructFunction = void (*)(v8::Isolate* isolate,
+                                   v8::Local<v8::Context> context,
+                                   FlagAndPersistent* flag_and_persistent);
+
+void ConstructJSObject(v8::Isolate* isolate, v8::Local<v8::Context> context,
+                       FlagAndPersistent* flag_and_persistent) {
+  v8::HandleScope handle_scope(isolate);
+  v8::Local<v8::Object> object(v8::Object::New(isolate));
+  CHECK(!object.IsEmpty());
+  flag_and_persistent->handle.Reset(isolate, object);
+  CHECK(!flag_and_persistent->handle.IsEmpty());
+}
+
+void ConstructJSApiObject(v8::Isolate* isolate, v8::Local<v8::Context> context,
+                          FlagAndPersistent* flag_and_persistent) {
+  v8::HandleScope handle_scope(isolate);
+  v8::Local<v8::FunctionTemplate> fun =
+      v8::FunctionTemplate::New(isolate, SimpleCallback);
+  v8::Local<v8::Object> object = fun->GetFunction(context)
+                                     .ToLocalChecked()
+                                     ->NewInstance(context)
+                                     .ToLocalChecked();
+  CHECK(!object.IsEmpty());
+  flag_and_persistent->handle.Reset(isolate, object);
+  CHECK(!flag_and_persistent->handle.IsEmpty());
+}
+
+enum class SurvivalMode { kSurvives, kDies };
+
+template <typename ModifierFunction, typename GCFunction>
+void WeakHandleTest(v8::Isolate* isolate, ConstructFunction construct_function,
+                    ModifierFunction modifier_function, GCFunction gc_function,
+                    SurvivalMode survives) {
+  v8::HandleScope scope(isolate);
+  v8::Local<v8::Context> context = v8::Context::New(isolate);
+  v8::Context::Scope context_scope(context);
+
+  FlagAndPersistent fp;
+  construct_function(isolate, context, &fp);
+  {
+    v8::HandleScope scope(isolate);
+    v8::Local<v8::Object> tmp = v8::Local<v8::Object>::New(isolate, fp.handle);
+    CHECK(
+        CcTest::i_isolate()->heap()->InNewSpace(*v8::Utils::OpenHandle(*tmp)));
+  }
+
+  fp.handle.SetWeak(&fp, &ResetHandleAndSetFlag,
+                    v8::WeakCallbackType::kParameter);
+  fp.flag = false;
+  modifier_function(&fp);
+  gc_function();
+  CHECK_IMPLIES(survives == SurvivalMode::kSurvives, !fp.flag);
+  CHECK_IMPLIES(survives == SurvivalMode::kDies, fp.flag);
+}
+
+void ResurrectingFinalizer(
+    const v8::WeakCallbackInfo<v8::Global<v8::Object>>& data) {
+  data.GetParameter()->ClearWeak();
+}
+
+void EmptyWeakCallback(const v8::WeakCallbackInfo<void>& data) {}
+
+void ResurrectingFinalizerSettingProperty(
+    const v8::WeakCallbackInfo<v8::Global<v8::Object>>& data) {
+  data.GetParameter()->ClearWeak();
+  v8::Local<v8::Object> o =
+      v8::Local<v8::Object>::New(data.GetIsolate(), *data.GetParameter());
+  o->Set(data.GetIsolate()->GetCurrentContext(), v8_str("finalizer"),
+         v8_str("was here"))
+      .FromJust();
+}
+
+}  // namespace
+
 TEST(EternalHandles) {
  CcTest::InitializeVM();
  Isolate* isolate = CcTest::i_isolate();
@ -117,10 +208,6 @@ TEST(PersistentBaseGetLocal) {
  CHECK(v8::Local<v8::Object>::New(isolate, g) == g.Get(isolate));
 }

-
-void WeakCallback(const v8::WeakCallbackInfo<void>& data) {}
-
-
 TEST(WeakPersistentSmi) {
  CcTest::InitializeVM();
  v8::Isolate* isolate = CcTest::isolate();
@ -130,16 +217,8 @@ TEST(WeakPersistentSmi) {
  v8::Global<v8::Number> g(isolate, n);

  // Should not crash.
-  g.SetWeak<void>(nullptr, &WeakCallback, v8::WeakCallbackType::kParameter);
-}
-
-void finalizer(const v8::WeakCallbackInfo<v8::Global<v8::Object>>& data) {
-  data.GetParameter()->ClearWeak();
-  v8::Local<v8::Object> o =
-      v8::Local<v8::Object>::New(data.GetIsolate(), *data.GetParameter());
-  o->Set(data.GetIsolate()->GetCurrentContext(), v8_str("finalizer"),
-         v8_str("was here"))
-      .FromJust();
+  g.SetWeak<void>(nullptr, &EmptyWeakCallback,
+                  v8::WeakCallbackType::kParameter);
 }

 TEST(FinalizerWeakness) {
@ -154,7 +233,8 @@ TEST(FinalizerWeakness) {
    v8::Local<v8::Object> o = v8::Object::New(isolate);
    identity = o->GetIdentityHash();
    g.Reset(isolate, o);
-    g.SetWeak(&g, finalizer, v8::WeakCallbackType::kFinalizer);
+    g.SetWeak(&g, &ResurrectingFinalizerSettingProperty,
+              v8::WeakCallbackType::kFinalizer);
  }

  CcTest::CollectAllAvailableGarbage();
@ -185,13 +265,101 @@ TEST(PhatomHandlesWithoutCallbacks) {
  CHECK_EQ(0u, isolate->NumberOfPhantomHandleResetsSinceLastCall());
 }

-namespace {
-
-void ResurrectingFinalizer(
-    const v8::WeakCallbackInfo<v8::Global<v8::Object>>& data) {
-  data.GetParameter()->ClearWeak();
+TEST(WeakHandleToUnmodifiedJSObjectSurvivesScavenge) {
+  CcTest::InitializeVM();
+  WeakHandleTest(
+      CcTest::isolate(), &ConstructJSObject, [](FlagAndPersistent* fp) {},
+      []() { CcTest::CollectGarbage(i::NEW_SPACE); }, SurvivalMode::kSurvives);
 }

+TEST(WeakHandleToUnmodifiedJSObjectDiesOnMarkCompact) {
+  CcTest::InitializeVM();
+  WeakHandleTest(
+      CcTest::isolate(), &ConstructJSObject, [](FlagAndPersistent* fp) {},
+      []() { CcTest::CollectGarbage(i::OLD_SPACE); }, SurvivalMode::kDies);
+}
+
+TEST(WeakHandleToUnmodifiedJSObjectSurvivesMarkCompactWhenInHandle) {
+  CcTest::InitializeVM();
+  WeakHandleTest(
+      CcTest::isolate(), &ConstructJSObject,
+      [](FlagAndPersistent* fp) {
+        v8::Local<v8::Object> handle =
+            v8::Local<v8::Object>::New(CcTest::isolate(), fp->handle);
+        USE(handle);
+      },
+      []() { CcTest::CollectGarbage(i::OLD_SPACE); }, SurvivalMode::kSurvives);
+}
+
+TEST(WeakHandleToUnmodifiedJSApiObjectDiesOnScavenge) {
+  CcTest::InitializeVM();
+  WeakHandleTest(
+      CcTest::isolate(), &ConstructJSApiObject, [](FlagAndPersistent* fp) {},
+      []() { CcTest::CollectGarbage(i::NEW_SPACE); }, SurvivalMode::kDies);
+}
+
+TEST(WeakHandleToUnmodifiedJSApiObjectSurvivesScavengeWhenInHandle) {
+  CcTest::InitializeVM();
+  WeakHandleTest(
+      CcTest::isolate(), &ConstructJSApiObject,
+      [](FlagAndPersistent* fp) {
+        v8::Local<v8::Object> handle =
+            v8::Local<v8::Object>::New(CcTest::isolate(), fp->handle);
+        USE(handle);
+      },
+      []() { CcTest::CollectGarbage(i::NEW_SPACE); }, SurvivalMode::kSurvives);
+}
+
+TEST(WeakHandleToUnmodifiedJSApiObjectDiesOnMarkCompact) {
+  CcTest::InitializeVM();
+  WeakHandleTest(
+      CcTest::isolate(), &ConstructJSApiObject, [](FlagAndPersistent* fp) {},
+      []() { CcTest::CollectGarbage(i::OLD_SPACE); }, SurvivalMode::kDies);
+}
+
+TEST(WeakHandleToUnmodifiedJSApiObjectSurvivesMarkCompactWhenInHandle) {
+  CcTest::InitializeVM();
+  WeakHandleTest(
+      CcTest::isolate(), &ConstructJSApiObject,
+      [](FlagAndPersistent* fp) {
+        v8::Local<v8::Object> handle =
+            v8::Local<v8::Object>::New(CcTest::isolate(), fp->handle);
+        USE(handle);
+      },
+      []() { CcTest::CollectGarbage(i::OLD_SPACE); }, SurvivalMode::kSurvives);
+}
+
+TEST(WeakHandleToActiveUnmodifiedJSApiObjectSurvivesScavenge) {
+  CcTest::InitializeVM();
+  WeakHandleTest(CcTest::isolate(), &ConstructJSApiObject,
+                 [](FlagAndPersistent* fp) { fp->handle.MarkActive(); },
+                 []() { CcTest::CollectGarbage(i::NEW_SPACE); },
+                 SurvivalMode::kSurvives);
+}
+
+TEST(WeakHandleToActiveUnmodifiedJSApiObjectDiesOnMarkCompact) {
+  CcTest::InitializeVM();
+  WeakHandleTest(CcTest::isolate(), &ConstructJSApiObject,
+                 [](FlagAndPersistent* fp) { fp->handle.MarkActive(); },
+                 []() { CcTest::CollectGarbage(i::OLD_SPACE); },
+                 SurvivalMode::kDies);
+}
+
+TEST(WeakHandleToActiveUnmodifiedJSApiObjectSurvivesMarkCompactWhenInHandle) {
+  CcTest::InitializeVM();
+  WeakHandleTest(
+      CcTest::isolate(), &ConstructJSApiObject,
+      [](FlagAndPersistent* fp) {
+        fp->handle.MarkActive();
+        v8::Local<v8::Object> handle =
+            v8::Local<v8::Object>::New(CcTest::isolate(), fp->handle);
+        USE(handle);
+      },
+      []() { CcTest::CollectGarbage(i::OLD_SPACE); }, SurvivalMode::kSurvives);
+}
+
+namespace {
+
 template <typename GCFunction>
 void TestFinalizerKeepsPhantomAlive(v8::Isolate* isolate,
                                    GCFunction gc_function) {
@ -246,5 +414,70 @@ TEST(FinalizerKeepsPhantomAliveOnScavenge) {
      });
 }

+namespace {
+
+void InvokeScavenge() { CcTest::CollectGarbage(i::NEW_SPACE); }
+
+void InvokeMarkSweep() { CcTest::CollectAllGarbage(); }
+
+void ForceScavenge2(const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
+  data.GetParameter()->flag = true;
+  InvokeScavenge();
+}
+
+void ForceScavenge1(const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
+  data.GetParameter()->handle.Reset();
+  data.SetSecondPassCallback(ForceScavenge2);
+}
+
+void ForceMarkSweep2(const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
+  data.GetParameter()->flag = true;
+  InvokeMarkSweep();
+}
+
+void ForceMarkSweep1(const v8::WeakCallbackInfo<FlagAndPersistent>& data) {
+  data.GetParameter()->handle.Reset();
+  data.SetSecondPassCallback(ForceMarkSweep2);
+}
+
+}  // namespace
+
+TEST(GCFromWeakCallbacks) {
+  v8::Isolate* isolate = CcTest::isolate();
+  v8::Locker locker(CcTest::isolate());
+  v8::HandleScope scope(isolate);
+  v8::Local<v8::Context> context = v8::Context::New(isolate);
+  v8::Context::Scope context_scope(context);
+
+  static const int kNumberOfGCTypes = 2;
+  typedef v8::WeakCallbackInfo<FlagAndPersistent>::Callback Callback;
+  Callback gc_forcing_callback[kNumberOfGCTypes] = {&ForceScavenge1,
+                                                    &ForceMarkSweep1};
+
+  typedef void (*GCInvoker)();
+  GCInvoker invoke_gc[kNumberOfGCTypes] = {&InvokeScavenge, &InvokeMarkSweep};
+
+  for (int outer_gc = 0; outer_gc < kNumberOfGCTypes; outer_gc++) {
+    for (int inner_gc = 0; inner_gc < kNumberOfGCTypes; inner_gc++) {
+      FlagAndPersistent fp;
+      ConstructJSApiObject(isolate, context, &fp);
+      {
+        v8::HandleScope scope(isolate);
+        v8::Local<v8::Object> tmp =
+            v8::Local<v8::Object>::New(isolate, fp.handle);
+        CHECK(CcTest::i_isolate()->heap()->InNewSpace(
+            *v8::Utils::OpenHandle(*tmp)));
+      }
+      fp.flag = false;
+      fp.handle.SetWeak(&fp, gc_forcing_callback[inner_gc],
+                        v8::WeakCallbackType::kParameter);
+      fp.handle.MarkIndependent();
+      invoke_gc[outer_gc]();
+      EmptyMessageQueues(isolate);
+      CHECK(fp.flag);
+    }
+  }
+}
+
 }  // namespace internal
 }  // namespace v8