/* * 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 MemoryPressureHandler_h #define MemoryPressureHandler_h #include <time.h> #include <wtf/FastAllocBase.h> namespace WebCore { typedef void (*LowMemoryHandler)(bool critical); class MemoryPressureHandler { WTF_MAKE_FAST_ALLOCATED; public: friend MemoryPressureHandler& memoryPressureHandler(); void install(); void setLowMemoryHandler(LowMemoryHandler handler) { ASSERT(!m_installed); m_lowMemoryHandler = handler; } private: void uninstall(); void holdOff(unsigned); MemoryPressureHandler(); ~MemoryPressureHandler(); void respondToMemoryPressure(); static void releaseMemory(bool critical); bool m_installed; time_t m_lastRespondTime; LowMemoryHandler m_lowMemoryHandler; }; // Function to obtain the global memory pressure object. MemoryPressureHandler& memoryPressureHandler(); } // namespace WebCore #endif // MemoryPressureHandler_h