webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 102 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/heap/CellContainer.h b/Source/JavaScriptCore/heap/CellContainer.h
new file mode 100644
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+++ b/Source/JavaScriptCore/heap/CellContainer.h
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+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#pragma once
+
+#include <wtf/StdLibExtras.h>
+
+namespace JSC {
+
+class Heap;
+class HeapCell;
+class LargeAllocation;
+class MarkedBlock;
+class WeakSet;
+class VM;
+
+typedef uint32_t HeapVersion;
+
+// This is how we abstract over either MarkedBlock& or LargeAllocation&. Put things in here as you
+// find need for them.
+
+class CellContainer {
+public:
+    CellContainer()
+        : m_encodedPointer(0)
+    {
+    }
+    
+    CellContainer(MarkedBlock& markedBlock)
+        : m_encodedPointer(bitwise_cast<uintptr_t>(&markedBlock))
+    {
+    }
+    
+    CellContainer(LargeAllocation& largeAllocation)
+        : m_encodedPointer(bitwise_cast<uintptr_t>(&largeAllocation) | isLargeAllocationBit)
+    {
+    }
+    
+    VM* vm() const;
+    Heap* heap() const;
+    
+    explicit operator bool() const { return !!m_encodedPointer; }
+    
+    bool isMarkedBlock() const { return m_encodedPointer && !(m_encodedPointer & isLargeAllocationBit); }
+    bool isLargeAllocation() const { return m_encodedPointer & isLargeAllocationBit; }
+    
+    MarkedBlock& markedBlock() const
+    {
+        ASSERT(isMarkedBlock());
+        return *bitwise_cast<MarkedBlock*>(m_encodedPointer);
+    }
+    
+    LargeAllocation& largeAllocation() const
+    {
+        ASSERT(isLargeAllocation());
+        return *bitwise_cast<LargeAllocation*>(m_encodedPointer - isLargeAllocationBit);
+    }
+    
+    void aboutToMark(HeapVersion markingVersion);
+    bool areMarksStale() const;
+    
+    bool isMarked(HeapCell*) const;
+    bool isMarked(HeapVersion markingVersion, HeapCell*) const;
+    
+    bool isNewlyAllocated(HeapCell*) const;
+    
+    void noteMarked();
+    void assertValidCell(VM&, HeapCell*) const;
+    
+    size_t cellSize() const;
+    
+    WeakSet& weakSet() const;
+    
+private:
+    static const uintptr_t isLargeAllocationBit = 1;
+    uintptr_t m_encodedPointer;
+};
+
+} // namespace JSC
+