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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. 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 CardSet_h
#define CardSet_h
#include <stdint.h>
#include <wtf/Assertions.h>
#include <wtf/Noncopyable.h>
namespace JSC {
template <size_t cardSize, size_t blockSize> class CardSet {
WTF_MAKE_NONCOPYABLE(CardSet);
public:
static const size_t cardCount = (blockSize + cardSize - 1) / cardSize;
CardSet()
{
memset(m_cards, 0, cardCount);
}
bool isCardMarkedForAtom(const void*);
void markCardForAtom(const void*);
uint8_t& cardForAtom(const void*);
bool isCardMarked(size_t);
bool testAndClear(size_t);
private:
uint8_t m_cards[cardCount];
COMPILE_ASSERT(!(cardSize & (cardSize - 1)), cardSet_cardSize_is_power_of_two);
COMPILE_ASSERT(!(cardCount & (cardCount - 1)), cardSet_cardCount_is_power_of_two);
};
template <size_t cardSize, size_t blockSize> uint8_t& CardSet<cardSize, blockSize>::cardForAtom(const void* ptr)
{
ASSERT(ptr > this && ptr < (reinterpret_cast<char*>(this) + cardCount * cardSize));
uintptr_t card = (reinterpret_cast<uintptr_t>(ptr) / cardSize) % cardCount;
return m_cards[card];
}
template <size_t cardSize, size_t blockSize> bool CardSet<cardSize, blockSize>::isCardMarkedForAtom(const void* ptr)
{
return cardForAtom(ptr);
}
template <size_t cardSize, size_t blockSize> void CardSet<cardSize, blockSize>::markCardForAtom(const void* ptr)
{
cardForAtom(ptr) = 1;
}
template <size_t cardSize, size_t blockSize> bool CardSet<cardSize, blockSize>::isCardMarked(size_t i)
{
ASSERT(i < cardCount);
return m_cards[i];
}
template <size_t cardSize, size_t blockSize> bool CardSet<cardSize, blockSize>::testAndClear(size_t i)
{
ASSERT(i < cardCount);
bool result = m_cards[i];
m_cards[i] = 0;
return result;
}
}
#endif
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