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

src/heap/objects-visiting-inl.h

 // Copyright 2012 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.
 
 #ifndef V8_OBJECTS_VISITING_INL_H_
 #define V8_OBJECTS_VISITING_INL_H_
 
 #include "src/heap/array-buffer-tracker.h"
 #include "src/heap/mark-compact.h"
 #include "src/heap/objects-visiting.h"
@@ skipping 619 matching lines @@
 
 template <typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::VisitJSFunctionWeakCode(
     Map* map, HeapObject* object) {
   typedef FlexibleBodyVisitor<StaticVisitor, JSFunction::BodyDescriptorWeakCode,
                               void> JSFunctionWeakCodeBodyVisitor;
   JSFunctionWeakCodeBodyVisitor::Visit(map, object);
 }
 
 template <typename ResultType, typename ConcreteVisitor>
-ResultType HeapVisitor<ResultType, ConcreteVisitor>::IterateBody(
-    HeapObject* object) {
+ResultType HeapVisitor<ResultType, ConcreteVisitor>::Visit(HeapObject* object) {
   Map* map = object->map();
   ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
   switch (static_cast<VisitorId>(map->visitor_id())) {
 #define CASE(type)   \
   case kVisit##type: \
     return visitor->Visit##type(map, type::cast(object));
     TYPED_VISITOR_ID_LIST(CASE)
 #undef CASE
     case kVisitShortcutCandidate:
       return visitor->VisitShortcutCandidate(map, ConsString::cast(object));
@@ skipping 10 matching lines @@
     case kVisitFreeSpace:
       return visitor->VisitFreeSpace(map, FreeSpace::cast(object));
     case kVisitorIdCount:
       UNREACHABLE();
   }
   UNREACHABLE();
   // Make the compiler happy.
   return ResultType();
 }
 
-#define VISIT(type)                                                         \
-  template <typename ResultType, typename ConcreteVisitor>                  \
-  ResultType HeapVisitor<ResultType, ConcreteVisitor>::Visit##type(         \
-      Map* map, type* object) {                                             \
-    int size = type::BodyDescriptor::SizeOf(map, object);                   \
-    type::BodyDescriptor::IterateBody(object, size,                         \
-                                      static_cast<ConcreteVisitor*>(this)); \
-    return static_cast<ResultType>(size);                                   \
+template <typename ResultType, typename ConcreteVisitor>
+void HeapVisitor<ResultType, ConcreteVisitor>::VisitMapPointer(
+    HeapObject* host, HeapObject** map) {
+  static_cast<ConcreteVisitor*>(this)->VisitPointer(
+      host, reinterpret_cast<Object**>(map));
+}
+
+template <typename ResultType, typename ConcreteVisitor>
+bool HeapVisitor<ResultType, ConcreteVisitor>::ShouldVisit(HeapObject* object) {
+  return true;
+}
+
+#define VISIT(type)                                                 \
+  template <typename ResultType, typename ConcreteVisitor>          \
+  ResultType HeapVisitor<ResultType, ConcreteVisitor>::Visit##type( \
+      Map* map, type* object) {                                     \
+    ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this); \
+    if (!visitor->ShouldVisit(object)) return ResultType();         \
+    int size = type::BodyDescriptor::SizeOf(map, object);           \
+    visitor->VisitMapPointer(object, object->map_slot());           \
+    type::BodyDescriptor::IterateBody(object, size, visitor);       \
+    return static_cast<ResultType>(size);                           \
   }
 TYPED_VISITOR_ID_LIST(VISIT)
 #undef VISIT
 
 template <typename ResultType, typename ConcreteVisitor>
 ResultType HeapVisitor<ResultType, ConcreteVisitor>::VisitShortcutCandidate(
     Map* map, ConsString* object) {
+  ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
+  if (!visitor->ShouldVisit(object)) return ResultType();
   int size = ConsString::BodyDescriptor::SizeOf(map, object);
+  visitor->VisitMapPointer(object, object->map_slot());
   ConsString::BodyDescriptor::IterateBody(object, size,
                                           static_cast<ConcreteVisitor*>(this));
   return static_cast<ResultType>(size);
 }
 
 template <typename ResultType, typename ConcreteVisitor>
 ResultType HeapVisitor<ResultType, ConcreteVisitor>::VisitNativeContext(
     Map* map, Context* object) {
+  ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
+  if (!visitor->ShouldVisit(object)) return ResultType();
   int size = Context::BodyDescriptor::SizeOf(map, object);
+  visitor->VisitMapPointer(object, object->map_slot());
   Context::BodyDescriptor::IterateBody(object, size,
                                        static_cast<ConcreteVisitor*>(this));
   return static_cast<ResultType>(size);
 }
 
 template <typename ResultType, typename ConcreteVisitor>
 ResultType HeapVisitor<ResultType, ConcreteVisitor>::VisitDataObject(
     Map* map, HeapObject* object) {
+  ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
+  if (!visitor->ShouldVisit(object)) return ResultType();
   int size = map->instance_size();
+  visitor->VisitMapPointer(object, object->map_slot());
   return static_cast<ResultType>(size);
 }
 
 template <typename ResultType, typename ConcreteVisitor>
 ResultType HeapVisitor<ResultType, ConcreteVisitor>::VisitJSObjectFast(
     Map* map, JSObject* object) {
+  ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
+  if (!visitor->ShouldVisit(object)) return ResultType();
   int size = JSObject::FastBodyDescriptor::SizeOf(map, object);
+  visitor->VisitMapPointer(object, object->map_slot());
   JSObject::FastBodyDescriptor::IterateBody(
       object, size, static_cast<ConcreteVisitor*>(this));
   return static_cast<ResultType>(size);
 }
 template <typename ResultType, typename ConcreteVisitor>
 ResultType HeapVisitor<ResultType, ConcreteVisitor>::VisitJSApiObject(
     Map* map, JSObject* object) {
+  ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
+  if (!visitor->ShouldVisit(object)) return ResultType();
   int size = JSObject::BodyDescriptor::SizeOf(map, object);
+  visitor->VisitMapPointer(object, object->map_slot());
   JSObject::BodyDescriptor::IterateBody(object, size,
                                         static_cast<ConcreteVisitor*>(this));
   return static_cast<ResultType>(size);
 }
 template <typename ResultType, typename ConcreteVisitor>
 ResultType HeapVisitor<ResultType, ConcreteVisitor>::VisitStruct(
     Map* map, HeapObject* object) {
+  ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
+  if (!visitor->ShouldVisit(object)) return ResultType();
   int size = map->instance_size();
+  visitor->VisitMapPointer(object, object->map_slot());
   StructBodyDescriptor::IterateBody(object, size,
                                     static_cast<ConcreteVisitor*>(this));
   return static_cast<ResultType>(size);
 }
 template <typename ResultType, typename ConcreteVisitor>
 ResultType HeapVisitor<ResultType, ConcreteVisitor>::VisitFreeSpace(
     Map* map, FreeSpace* object) {
+  ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
+  if (!visitor->ShouldVisit(object)) return ResultType();
+  visitor->VisitMapPointer(object, object->map_slot());
   return static_cast<ResultType>(FreeSpace::cast(object)->size());
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_VISITING_INL_H_