JavaScriptCore-1218.tar.gz

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

diff --git a/heap/CopyWorkList.h b/heap/CopyWorkList.h
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+/*
+ * Copyright (C) 2012 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. AND ITS CONTRIBUTORS ``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 ITS 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 CopyWorkList_h
+#define CopyWorkList_h
+
+#include <wtf/Vector.h>
+
+namespace JSC {
+
+class JSCell;
+
+class CopyWorkListSegment : public HeapBlock<CopyWorkListSegment> {
+public:
+    static CopyWorkListSegment* create(DeadBlock* block)
+    {
+        return new (NotNull, block) CopyWorkListSegment(block->region());
+    }
+
+    size_t size() { return m_size; }
+    bool isFull() { return reinterpret_cast<char*>(&data()[size()]) >= endOfBlock(); }
+    JSCell* get(size_t index) { return data()[index]; }
+
+    void append(JSCell* cell)
+    {
+        ASSERT(!isFull());
+        data()[m_size] = cell;
+        m_size += 1;
+    }
+
+    static const size_t blockSize = 512;
+
+private:
+    CopyWorkListSegment(Region* region)
+        : HeapBlock<CopyWorkListSegment>(region)
+        , m_size(0)
+    {
+    }
+
+    JSCell** data() { return reinterpret_cast<JSCell**>(this + 1); }
+    char* endOfBlock() { return reinterpret_cast<char*>(this) + blockSize; }
+
+    size_t m_size;
+};
+
+class CopyWorkListIterator {
+    friend class CopyWorkList;
+public:
+    JSCell* get() { return m_currentSegment->get(m_currentIndex); }
+    JSCell* operator*() { return get(); }
+    JSCell* operator->() { return get(); }
+
+    CopyWorkListIterator& operator++()
+    {
+        m_currentIndex++;
+
+        if (m_currentIndex >= m_currentSegment->size()) {
+            m_currentIndex = 0;
+            m_currentSegment = m_currentSegment->next();
+        
+            ASSERT(!m_currentSegment || m_currentSegment->size());
+        }
+
+        return *this;
+    }
+
+    bool operator==(const CopyWorkListIterator& other) const
+    {
+        return m_currentSegment == other.m_currentSegment && m_currentIndex == other.m_currentIndex;
+    }
+    
+    bool operator!=(const CopyWorkListIterator& other) const
+    {
+        return !(*this == other);
+    }
+
+    CopyWorkListIterator()
+        : m_currentSegment(0)
+        , m_currentIndex(0)
+    {
+    }
+
+private:
+    CopyWorkListIterator(CopyWorkListSegment* startSegment, size_t startIndex)
+        : m_currentSegment(startSegment)
+        , m_currentIndex(startIndex)
+    {
+    }
+    
+    CopyWorkListSegment* m_currentSegment;
+    size_t m_currentIndex;
+};
+
+class CopyWorkList {
+public:
+    typedef CopyWorkListIterator iterator;
+
+    CopyWorkList(BlockAllocator&);
+    ~CopyWorkList();
+
+    void append(JSCell*);
+    iterator begin();
+    iterator end();
+
+private:
+    DoublyLinkedList<CopyWorkListSegment> m_segments;
+    BlockAllocator& m_blockAllocator;
+};
+
+inline CopyWorkList::CopyWorkList(BlockAllocator& blockAllocator)
+    : m_blockAllocator(blockAllocator)
+{
+}
+
+inline CopyWorkList::~CopyWorkList()
+{
+    while (!m_segments.isEmpty())
+        m_blockAllocator.deallocate(CopyWorkListSegment::destroy(m_segments.removeHead()));
+}
+
+inline void CopyWorkList::append(JSCell* cell)
+{
+    if (m_segments.isEmpty() || m_segments.tail()->isFull())
+        m_segments.append(CopyWorkListSegment::create(m_blockAllocator.allocate<CopyWorkListSegment>()));
+
+    ASSERT(!m_segments.tail()->isFull());
+
+    m_segments.tail()->append(cell);
+}
+
+inline CopyWorkList::iterator CopyWorkList::begin()
+{
+    return CopyWorkListIterator(m_segments.head(), 0);
+}
+
+inline CopyWorkList::iterator CopyWorkList::end()
+{
+    return CopyWorkListIterator();
+}
+
+} // namespace JSC
+
+#endif // CopyWorkList_h