/* * Copyright (C) 2014-2018 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 SmallPage_h #define SmallPage_h #include "BAssert.h" #include "List.h" #include "Mutex.h" #include "VMAllocate.h" #include namespace bmalloc { class SmallLine; class SmallPage : public ListNode { public: void ref(UniqueLockHolder&); bool deref(UniqueLockHolder&); unsigned refCount(UniqueLockHolder&) { return m_refCount; } size_t sizeClass() { return m_sizeClass; } void setSizeClass(size_t sizeClass) { m_sizeClass = sizeClass; } bool hasFreeLines(UniqueLockHolder&) const { return m_hasFreeLines; } void setHasFreeLines(UniqueLockHolder&, bool hasFreeLines) { m_hasFreeLines = hasFreeLines; } bool hasPhysicalPages() { return m_hasPhysicalPages; } void setHasPhysicalPages(bool hasPhysicalPages) { m_hasPhysicalPages = hasPhysicalPages; } bool usedSinceLastScavenge() { return m_usedSinceLastScavenge; } void clearUsedSinceLastScavenge() { m_usedSinceLastScavenge = false; } void setUsedSinceLastScavenge() { m_usedSinceLastScavenge = true; } SmallLine* begin(); unsigned char slide() const { return m_slide; } void setSlide(unsigned char slide) { m_slide = slide; } private: unsigned char m_hasFreeLines: 1; unsigned char m_hasPhysicalPages: 1; unsigned char m_usedSinceLastScavenge: 1; unsigned char m_refCount: 7; unsigned char m_sizeClass; unsigned char m_slide; static_assert( sizeClassCount <= std::numeric_limits::max(), "Largest size class must fit in SmallPage metadata"); }; using LineCache = std::array, sizeClassCount>; inline void SmallPage::ref(UniqueLockHolder&) { BASSERT(!m_slide); ++m_refCount; BASSERT(m_refCount); } inline bool SmallPage::deref(UniqueLockHolder&) { BASSERT(!m_slide); BASSERT(m_refCount); --m_refCount; return !m_refCount; } } // namespace bmalloc #endif // SmallPage_h