70 lines
2.1 KiB
C++
70 lines
2.1 KiB
C++
/*
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* Copyright (C) 2014-2018 Apple Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
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* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef SmallLine_h
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#define SmallLine_h
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#include "BAssert.h"
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#include "Mutex.h"
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#include "ObjectType.h"
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#include <mutex>
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namespace bmalloc {
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class SmallLine {
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public:
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void ref(UniqueLockHolder&, unsigned char = 1);
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bool deref(UniqueLockHolder&);
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unsigned refCount(UniqueLockHolder&) { return m_refCount; }
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char* begin();
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char* end();
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private:
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unsigned char m_refCount;
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static_assert(
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smallLineSize / alignment <= std::numeric_limits<decltype(m_refCount)>::max(),
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"maximum object count must fit in SmallLine::m_refCount");
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};
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inline void SmallLine::ref(UniqueLockHolder&, unsigned char refCount)
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{
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BASSERT(!m_refCount);
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m_refCount = refCount;
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}
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inline bool SmallLine::deref(UniqueLockHolder&)
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{
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BASSERT(m_refCount);
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--m_refCount;
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return !m_refCount;
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}
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} // namespace bmalloc
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#endif // SmallLine_h
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