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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:
static CopiedBlock* create(const PageAllocationAligned&);
static CopiedBlock* createNoZeroFill(const PageAllocationAligned&);
static PageAllocationAligned destroy(CopiedBlock*);
// The payload is the region of the block that is usable for allocations.
char* payload();
char* payloadEnd();
size_t payloadCapacity();
// The data is the region of the block that has been used for allocations.
char* data();
char* dataEnd();
size_t dataSize();
// The wilderness is the region of the block that is usable for allocations
// but has not been so used.
char* wilderness();
char* wildernessEnd();
size_t wildernessSize();
size_t size();
size_t capacity();
private:
CopiedBlock(const PageAllocationAligned&);
void zeroFillWilderness(); // Can be called at any time to zero-fill to the end of the block.
size_t m_remaining;
uintptr_t m_isPinned;
};
inline CopiedBlock* CopiedBlock::createNoZeroFill(const PageAllocationAligned& allocation)
{
return new(NotNull, allocation.base()) CopiedBlock(allocation);
}
inline CopiedBlock* CopiedBlock::create(const PageAllocationAligned& allocation)
{
CopiedBlock* block = createNoZeroFill(allocation);
block->zeroFillWilderness();
return block;
}
inline void CopiedBlock::zeroFillWilderness()
{
#if USE(JSVALUE64)
memset(wilderness(), 0, wildernessSize());
#else
JSValue emptyValue;
JSValue* limit = reinterpret_cast_ptr<JSValue*>(wildernessEnd());
for (JSValue* currentValue = reinterpret_cast<JSValue*>(wilderness()); currentValue < limit; currentValue++)
*currentValue = emptyValue;
#endif
}
inline PageAllocationAligned CopiedBlock::destroy(CopiedBlock* block)
{
PageAllocationAligned allocation;
swap(allocation, block->m_allocation);
block->~CopiedBlock();
return allocation;
}
inline CopiedBlock::CopiedBlock(const PageAllocationAligned& allocation)
: HeapBlock(allocation)
, m_remaining(payloadCapacity())
, m_isPinned(false)
{
ASSERT(is8ByteAligned(reinterpret_cast<void*>(m_remaining)));
}
inline char* CopiedBlock::payload()
{
return reinterpret_cast<char*>(this) + ((sizeof(CopiedBlock) + 7) & ~7);
}
inline char* CopiedBlock::payloadEnd()
{
return reinterpret_cast<char*>(this) + m_allocation.size();
}
inline size_t CopiedBlock::payloadCapacity()
{
return payloadEnd() - payload();
}
inline char* CopiedBlock::data()
{
return payload();
}
inline char* CopiedBlock::dataEnd()
{
return payloadEnd() - m_remaining;
}
inline size_t CopiedBlock::dataSize()
{
return dataEnd() - data();
}
inline char* CopiedBlock::wilderness()
{
return dataEnd();
}
inline char* CopiedBlock::wildernessEnd()
{
return payloadEnd();
}
inline size_t CopiedBlock::wildernessSize()
{
return wildernessEnd() - wilderness();
}
inline size_t CopiedBlock::size()
{
return dataSize();
}
inline size_t CopiedBlock::capacity()
{
return m_allocation.size();
}
} // namespace JSC
#endif
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