src/third_party/WebKit/Source/JavaScriptCore/heap/CopiedSpace.h

/*
 * 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 CopiedSpace_h
#define CopiedSpace_h

#include "CopiedAllocator.h"
#include "HeapBlock.h"
#include "TinyBloomFilter.h"
#include <wtf/Assertions.h>
#include <wtf/CheckedBoolean.h>
#include <wtf/DoublyLinkedList.h>
#include <wtf/HashSet.h>
#include <wtf/OSAllocator.h>
#include <wtf/PageAllocationAligned.h>
#include <wtf/PageBlock.h>
#include <wtf/StdLibExtras.h>
#include <wtf/TCSpinLock.h>
#include <wtf/ThreadingPrimitives.h>

namespace JSC {

class Heap;
class CopiedBlock;

class CopiedSpace {
    friend class CopyVisitor;
    friend class GCThreadSharedData;
    friend class SlotVisitor;
    friend class JIT;
public:
    CopiedSpace(Heap*);
    ~CopiedSpace();
    void init();

    CheckedBoolean tryAllocate(size_t, void**);
    CheckedBoolean tryReallocate(void**, size_t, size_t);
    
    CopiedAllocator& allocator() { return m_allocator; }

    void startedCopying();
    void doneCopying();
    bool isInCopyPhase() { return m_inCopyingPhase; }

    void pin(CopiedBlock*);
    bool isPinned(void*);

    bool contains(CopiedBlock*);
    bool contains(void*, CopiedBlock*&);
    
    void pinIfNecessary(void* pointer);

    size_t size();
    size_t capacity();

    bool isPagedOut(double deadline);
    bool shouldDoCopyPhase() { return m_shouldDoCopyPhase; }

    void freeAllBlocks();

    static CopiedBlock* blockFor(void*);

private:
    static bool isOversize(size_t);
    static CopiedBlock* oversizeBlockFor(void* ptr);

    JS_EXPORT_PRIVATE CheckedBoolean tryAllocateSlowCase(size_t, void**);
    CheckedBoolean tryAllocateOversize(size_t, void**);
    CheckedBoolean tryReallocateOversize(void**, size_t, size_t);
    
    void allocateBlock();
    CopiedBlock* allocateBlockForCopyingPhase();

    void doneFillingBlock(CopiedBlock*, CopiedBlock**);
    void recycleEvacuatedBlock(CopiedBlock*);
    void recycleBorrowedBlock(CopiedBlock*);

    Heap* m_heap;

    CopiedAllocator m_allocator;

    TinyBloomFilter m_blockFilter;
    HashSet<CopiedBlock*> m_blockSet;

    SpinLock m_toSpaceLock;

    DoublyLinkedList<CopiedBlock>* m_toSpace;
    DoublyLinkedList<CopiedBlock>* m_fromSpace;
    
    DoublyLinkedList<CopiedBlock> m_blocks1;
    DoublyLinkedList<CopiedBlock> m_blocks2;
    DoublyLinkedList<CopiedBlock> m_oversizeBlocks;
   
    bool m_inCopyingPhase;
    bool m_shouldDoCopyPhase;

    Mutex m_loanedBlocksLock; 
    ThreadCondition m_loanedBlocksCondition;
    size_t m_numberOfLoanedBlocks;

    static const size_t s_maxAllocationSize = CopiedBlock::blockSize / 2;
    static const size_t s_initialBlockNum = 16;
    static const size_t s_blockMask = ~(CopiedBlock::blockSize - 1);
};

} // namespace JSC

#endif