JavaScriptCore-1097.3.tar.gz

[apple/javascriptcore.git] / heap / CopiedBlock.h

diff --git a/heap/CopiedBlock.h b/heap/CopiedBlock.h
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+/*
+ * Copyright (C) 2011 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. 
+ */
+
+#ifndef CopiedBlock_h
+#define CopiedBlock_h
+
+#include "HeapBlock.h"
+#include "JSValue.h"
+#include "JSValueInlineMethods.h"
+
+namespace JSC {
+
+class CopiedSpace;
+
+class CopiedBlock : public HeapBlock {
+    friend class CopiedSpace;
+    friend class CopiedAllocator;
+public:
+    CopiedBlock(PageAllocationAligned& allocation)
+        : HeapBlock(allocation)
+        , m_offset(payload())
+        , m_isPinned(false)
+    {
+        ASSERT(is8ByteAligned(static_cast<void*>(m_offset)));
+#if USE(JSVALUE64)
+        char* offset = static_cast<char*>(m_offset);
+        memset(static_cast<void*>(offset), 0, static_cast<size_t>((reinterpret_cast<char*>(this) + allocation.size()) - offset));
+#else
+        JSValue emptyValue;
+        JSValue* limit = reinterpret_cast_ptr<JSValue*>(reinterpret_cast<char*>(this) + allocation.size());
+        for (JSValue* currentValue = reinterpret_cast<JSValue*>(m_offset); currentValue < limit; currentValue++)
+            *currentValue = emptyValue;
+#endif
+    }
+
+    char* payload();
+    size_t size();
+    size_t capacity();
+
+private:
+    void* m_offset;
+    uintptr_t m_isPinned;
+};
+
+inline char* CopiedBlock::payload()
+{
+    return reinterpret_cast<char*>(this) + ((sizeof(CopiedBlock) + 7) & ~7);
+}
+
+inline size_t CopiedBlock::size()
+{
+    return static_cast<size_t>(static_cast<char*>(m_offset) - payload());
+}
+
+inline size_t CopiedBlock::capacity()
+{
+    return m_allocation.size();
+}
+
+} // namespace JSC
+
+#endif