webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 28 insertions, 27 deletions

diff --git a/Source/JavaScriptCore/heap/WeakBlock.h b/Source/JavaScriptCore/heap/WeakBlock.h
index b6b631e27..6d4ff0709 100644
--- a/Source/JavaScriptCore/heap/WeakBlock.h
+++ b/Source/JavaScriptCore/heap/WeakBlock.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 Apple Inc. All rights reserved.
+ * Copyright (C) 2012-2017 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,73 +23,71 @@
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef WeakBlock_h
-#define WeakBlock_h
+#pragma once
 
-#include "HeapBlock.h"
-#include "WeakHandleOwner.h"
+#include "CellContainer.h"
 #include "WeakImpl.h"
 #include <wtf/DoublyLinkedList.h>
 #include <wtf/StdLibExtras.h>
 
 namespace JSC {
 
-class DeadBlock;
-class HeapRootVisitor;
-class JSValue;
-class WeakHandleOwner;
+class Heap;
+class SlotVisitor;
 
-class WeakBlock : public HeapBlock<WeakBlock> {
+class WeakBlock : public DoublyLinkedListNode<WeakBlock> {
 public:
     friend class WTF::DoublyLinkedListNode<WeakBlock>;
-    static const size_t blockSize = 4 * KB; // 5% of MarkedBlock size
+    static const size_t blockSize = 256; // 1/16 of MarkedBlock size
 
     struct FreeCell {
         FreeCell* next;
     };
 
     struct SweepResult {
-        SweepResult();
         bool isNull() const;
 
-        bool blockIsFree;
-        FreeCell* freeList;
+        bool blockIsFree { true };
+        bool blockIsLogicallyEmpty { true };
+        FreeCell* freeList { nullptr };
     };
 
-    static WeakBlock* create(DeadBlock*);
+    static WeakBlock* create(Heap&, CellContainer);
+    static void destroy(Heap&, WeakBlock*);
 
     static WeakImpl* asWeakImpl(FreeCell*);
 
     bool isEmpty();
+    bool isLogicallyEmptyButNotFree() const;
 
     void sweep();
     SweepResult takeSweepResult();
 
-    void visit(HeapRootVisitor&);
+    void visit(SlotVisitor&);
+
     void reap();
 
     void lastChanceToFinalize();
+    void disconnectContainer() { m_container = CellContainer(); }
 
 private:
     static FreeCell* asFreeCell(WeakImpl*);
+    
+    template<typename ContainerType>
+    void specializedVisit(ContainerType&, SlotVisitor&);
 
-    WeakBlock(Region*);
-    WeakImpl* firstWeakImpl();
+    explicit WeakBlock(CellContainer);
     void finalize(WeakImpl*);
     WeakImpl* weakImpls();
     size_t weakImplCount();
     void addToFreeList(FreeCell**, WeakImpl*);
 
+    CellContainer m_container;
+    WeakBlock* m_prev;
+    WeakBlock* m_next;
     SweepResult m_sweepResult;
 };
 
-inline WeakBlock::SweepResult::SweepResult()
-    : blockIsFree(true)
-    , freeList(0)
-{
-    ASSERT(isNull());
-}
-
 inline bool WeakBlock::SweepResult::isNull() const
 {
     return blockIsFree && !freeList; // This state is impossible, so we can use it to mean null.
@@ -138,6 +136,9 @@ inline bool WeakBlock::isEmpty()
     return !m_sweepResult.isNull() && m_sweepResult.blockIsFree;
 }
 
-} // namespace JSC
+inline bool WeakBlock::isLogicallyEmptyButNotFree() const
+{
+    return !m_sweepResult.isNull() && !m_sweepResult.blockIsFree && m_sweepResult.blockIsLogicallyEmpty;
+}
 
-#endif // WeakBlock_h
+} // namespace JSC