[heap] Reland "Use shared markbits in the concurrent marker."

src/heap/concurrent-marking.cc

 // Copyright 2017 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/concurrent-marking.h"
 
 #include <stack>
 #include <unordered_map>
 
 #include "src/heap/concurrent-marking-deque.h"
@@ skipping 12 matching lines @@
 namespace internal {
 
 class ConcurrentMarkingVisitor final
     : public HeapVisitor<int, ConcurrentMarkingVisitor> {
  public:
   using BaseClass = HeapVisitor<int, ConcurrentMarkingVisitor>;
 
   explicit ConcurrentMarkingVisitor(ConcurrentMarkingDeque* deque)
       : deque_(deque) {}
 
+  bool ShouldVisit(HeapObject* object) override {
+    return ObjectMarking::GreyToBlack<MarkBit::AccessMode::ATOMIC>(
+        object, marking_state(object));
+  }
+
   void VisitPointers(HeapObject* host, Object** start, Object** end) override {
     for (Object** p = start; p < end; p++) {
       if (!(*p)->IsHeapObject()) continue;
       MarkObject(HeapObject::cast(*p));
     }
   }
 
   // ===========================================================================
   // JS object =================================================================
   // ===========================================================================
@@ skipping 18 matching lines @@
   int VisitFixedArray(Map* map, FixedArray* object) override {
     // TODO(ulan): implement iteration with prefetched length.
     return BaseClass::VisitFixedArray(map, object);
   }
 
   // ===========================================================================
   // Code object ===============================================================
   // ===========================================================================
 
   int VisitCode(Map* map, Code* object) override {
-    // TODO(ulan): push the object to the bail-out deque.
+    deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kBailout);
     return 0;
   }
 
   // ===========================================================================
   // Objects with weak fields and/or side-effectiful visitation.
   // ===========================================================================
 
   int VisitBytecodeArray(Map* map, BytecodeArray* object) override {
-    // TODO(ulan): implement iteration of strong fields and push the object to
-    // the bailout deque.
+    // TODO(ulan): implement iteration of strong fields.
+    deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kBailout);
     return 0;
   }
 
   int VisitJSFunction(Map* map, JSFunction* object) override {
-    // TODO(ulan): implement iteration of strong fields and push the object to
-    // the bailout deque.
+    // TODO(ulan): implement iteration of strong fields.
+    deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kBailout);
     return 0;
   }
 
   int VisitMap(Map* map, Map* object) override {
-    // TODO(ulan): implement iteration of strong fields and push the object to
-    // the bailout deque.
+    // TODO(ulan): implement iteration of strong fields.
+    deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kBailout);
     return 0;
   }
 
   int VisitNativeContext(Map* map, Context* object) override {
-    // TODO(ulan): implement iteration of strong fields and push the object to
-    // the bailout deque.
+    // TODO(ulan): implement iteration of strong fields.
+    deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kBailout);
     return 0;
   }
 
   int VisitSharedFunctionInfo(Map* map, SharedFunctionInfo* object) override {
-    // TODO(ulan): implement iteration of strong fields and push the object to
-    // the bailout deque.
+    // TODO(ulan): implement iteration of strong fields.
+    deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kBailout);
     return 0;
   }
 
   int VisitTransitionArray(Map* map, TransitionArray* object) override {
-    // TODO(ulan): implement iteration of strong fields and push the object to
-    // the bailout deque.
+    // TODO(ulan): implement iteration of strong fields.
+    deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kBailout);
     return 0;
   }
 
   int VisitWeakCell(Map* map, WeakCell* object) override {
-    // TODO(ulan): implement iteration of strong fields and push the object to
-    // the bailout deque.
+    // TODO(ulan): implement iteration of strong fields.
+    deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kBailout);
     return 0;
   }
 
   int VisitJSWeakCollection(Map* map, JSWeakCollection* object) override {
-    // TODO(ulan): implement iteration of strong fields and push the object to
-    // the bailout deque.
+    // TODO(ulan): implement iteration of strong fields.
+    deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kBailout);
     return 0;
   }
 
-  void MarkObject(HeapObject* obj) {
-    deque_->Push(obj, MarkingThread::kConcurrent, TargetDeque::kShared);
+  void MarkObject(HeapObject* object) {
+    if (ObjectMarking::WhiteToGrey<MarkBit::AccessMode::ATOMIC>(
+            object, marking_state(object))) {
+      deque_->Push(object, MarkingThread::kConcurrent, TargetDeque::kShared);
+    }
   }
 
  private:
+  MarkingState marking_state(HeapObject* object) const {
+    return MarkingState::Internal(object);
+  }
+
   ConcurrentMarkingDeque* deque_;
 };
 
 class ConcurrentMarking::Task : public CancelableTask {
  public:
   Task(Isolate* isolate, ConcurrentMarking* concurrent_marking,
        base::Semaphore* on_finish)
       : CancelableTask(isolate),
         concurrent_marking_(concurrent_marking),
         on_finish_(on_finish) {}
@@ skipping 26 matching lines @@
 
 ConcurrentMarking::~ConcurrentMarking() { delete visitor_; }
 
 void ConcurrentMarking::Run() {
   double time_ms = heap_->MonotonicallyIncreasingTimeInMs();
   size_t bytes_marked = 0;
   {
     TimedScope scope(&time_ms);
     HeapObject* object;
     while ((object = deque_->Pop(MarkingThread::kConcurrent)) != nullptr) {
-      bytes_marked += visitor_->IterateBody(object);
+      bytes_marked += visitor_->Visit(object);
     }
   }
   if (FLAG_trace_concurrent_marking) {
     heap_->isolate()->PrintWithTimestamp("concurrently marked %dKB in %.2fms\n",
                                          static_cast<int>(bytes_marked / KB),
                                          time_ms);
   }
 }
 
 void ConcurrentMarking::StartTask() {
@@ skipping 11 matching lines @@
 }
 
 void ConcurrentMarking::EnsureTaskCompleted() {
   if (IsTaskPending()) {
     WaitForTaskToComplete();
   }
 }
 
 }  // namespace internal
 }  // namespace v8