| /* |
| * 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 |