Add a generic remembered set class.

src/heap/remembered-set.cc

+// Copyright 2016 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/remembered-set.h"
+#include "src/heap/heap-inl.h"
+#include "src/heap/heap.h"
+#include "src/heap/mark-compact.h"
+#include "src/heap/slot-set.h"
+#include "src/heap/spaces.h"
+#include "src/heap/store-buffer.h"
+
+namespace v8 {
+namespace internal {
+
+template <PointerDirection direction>

[Hannes Payer (out of office), 2016/02/15 16:53:38]

Are you using direction just for now for sanity check?

[ulan, 2016/02/16 10:24:52]

Yes.

+void RememberedSet<direction>::ClearInvalidSlots(Heap* heap) {
+  STATIC_ASSERT(direction == OLD_TO_NEW);
+  PageIterator it(heap->old_space());
+  MemoryChunk* chunk;
+  while (it.has_next()) {
+    chunk = it.next();
+    SlotSet* slots = GetSlotSet(chunk);
+    if (slots != nullptr) {
+      slots->Iterate([heap](Address addr) {
+        Object** slot = reinterpret_cast<Object**>(addr);
+        return IsValidSlot(heap, slot) ? SlotSet::KEEP_SLOT
+                                       : SlotSet::REMOVE_SLOT;
+      });
+    }
+  }
+}
+
+template <PointerDirection direction>
+void RememberedSet<direction>::VerifyValidSlots(Heap* heap) {
+  STATIC_ASSERT(direction == OLD_TO_NEW);
+  Iterate(heap, [heap](Address addr) {
+    Object** slot = reinterpret_cast<Object**>(addr);
+    Object* object = *slot;
+    if (Page::FromAddress(addr)->owner() != nullptr &&
+        Page::FromAddress(addr)->owner()->identity() == OLD_SPACE) {
+      CHECK(IsValidSlot(heap, slot));
+      heap->mark_compact_collector()->VerifyIsSlotInLiveObject(
+          reinterpret_cast<Address>(slot), HeapObject::cast(object));
+    }
+    return SlotSet::KEEP_SLOT;
+  });
+}
+
+template <PointerDirection direction>
+bool RememberedSet<direction>::IsValidSlot(Heap* heap, Object** slot) {
+  STATIC_ASSERT(direction == OLD_TO_NEW);
+  Object* object = *slot;
+  if (!heap->InNewSpace(object)) {
+    return false;
+  }
+  HeapObject* heap_object = HeapObject::cast(object);
+  // If the target object is not black, the source slot must be part
+  // of a non-black (dead) object.
+  return Marking::IsBlack(Marking::MarkBitFrom(heap_object)) &&
+         heap->mark_compact_collector()->IsSlotInLiveObject(
+             reinterpret_cast<Address>(slot));
+}
+
+template void RememberedSet<OLD_TO_NEW>::ClearInvalidSlots(Heap* heap);
+template void RememberedSet<OLD_TO_NEW>::VerifyValidSlots(Heap* heap);
+
+}  // namespace internal
+}  // namespace v8