Simple BlinkGC heap compaction.

third_party/WebKit/Source/platform/heap/HeapTest.cpp

Index: third_party/WebKit/Source/platform/heap/HeapTest.cpp
diff --git a/third_party/WebKit/Source/platform/heap/HeapTest.cpp b/third_party/WebKit/Source/platform/heap/HeapTest.cpp
index 5570f70fb115788ddbc9fda0c0b7dc89217792d4..6016920bdd70b4cbfd46456bcf96833fb0837abd 100644
--- a/third_party/WebKit/Source/platform/heap/HeapTest.cpp
+++ b/third_party/WebKit/Source/platform/heap/HeapTest.cpp
@@ -332,7 +332,7 @@ class CountingVisitor : public Visitor {
     m_count++;
   }
 
-  void registerDelayedMarkNoTracing(const void*) override {}
+  void registerDelayedMarkNoTracing(void**) override {}
   void registerWeakMembers(const void*, const void*, WeakCallback) override {}
   void registerWeakTable(const void*,
                          EphemeronCallback,
@@ -349,6 +349,12 @@ class CountingVisitor : public Visitor {
     return true;
   }
 
+  void registerMovingObjectReference(MovableReference*) override {}
+
+  void registerMovingObjectCallback(MovableReference,
+                                    MovingObjectCallback,
+                                    void*) override {}
+
   size_t count() { return m_count; }
   void reset() { m_count = 0; }
 
@@ -3765,6 +3771,7 @@ TEST(HeapTest, RefCountedGarbageCollectedWithStackPointers) {
       pointer1 = object1.get();
       pointer2 = object2.get();
       void* objects[2] = {object1.get(), object2.get()};
+      ThreadState::GCForbiddenScope gcScope(ThreadState::current());

[haraken, 2016/12/09 07:25:56]

Would you help me understand why these GCForbiddenScopes are needed?

[sof, 2016/12/09 21:44:04]

As long as there's a DCHECK() in the Visitor constructor that GC is forbidden
during its lifetime, they by definition are needed here.

[haraken, 2016/12/12 01:25:10]

Makes sense. I'm wondering if we can/should unify GCForbiddenScope and
SweepForbiddenScope somehow. It's getting unclearer when we should use which one
or both.

       RefCountedGarbageCollectedVisitor visitor(ThreadState::current(), 2,
                                                 objects);
       ThreadState::current()->visitPersistents(&visitor);
@@ -3782,6 +3789,7 @@ TEST(HeapTest, RefCountedGarbageCollectedWithStackPointers) {
       // At this point, the reference counts of object1 and object2 are 0.
       // Only pointer1 and pointer2 keep references to object1 and object2.
       void* objects[] = {0};
+      ThreadState::GCForbiddenScope gcScope(ThreadState::current());
       RefCountedGarbageCollectedVisitor visitor(ThreadState::current(), 0,
                                                 objects);
       ThreadState::current()->visitPersistents(&visitor);
@@ -3792,6 +3800,7 @@ TEST(HeapTest, RefCountedGarbageCollectedWithStackPointers) {
       Persistent<RefCountedAndGarbageCollected> object1(pointer1);
       Persistent<RefCountedAndGarbageCollected2> object2(pointer2);
       void* objects[2] = {object1.get(), object2.get()};
+      ThreadState::GCForbiddenScope gcScope(ThreadState::current());
       RefCountedGarbageCollectedVisitor visitor(ThreadState::current(), 2,
                                                 objects);
       ThreadState::current()->visitPersistents(&visitor);
@@ -3955,6 +3964,7 @@ TEST(HeapTest, CheckAndMarkPointer) {
   // checkAndMarkPointer tests.
   {
     TestGCScope scope(BlinkGC::HeapPointersOnStack);
+    ThreadState::GCForbiddenScope gcScope(ThreadState::current());
     CountingVisitor visitor(ThreadState::current());
     EXPECT_TRUE(scope.allThreadsParked());  // Fail the test if we could not
                                             // park all threads.
@@ -3976,6 +3986,7 @@ TEST(HeapTest, CheckAndMarkPointer) {
   clearOutOldGarbage();
   {
     TestGCScope scope(BlinkGC::HeapPointersOnStack);
+    ThreadState::GCForbiddenScope gcScope(ThreadState::current());
     CountingVisitor visitor(ThreadState::current());
     EXPECT_TRUE(scope.allThreadsParked());
     heap.flushHeapDoesNotContainCache();
@@ -5874,6 +5885,7 @@ class PartObject {
 };
 
 TEST(HeapTest, TraceIfNeeded) {
+  ThreadState::GCForbiddenScope scope(ThreadState::current());
   CountingVisitor visitor(ThreadState::current());
 
   {