/* * Copyright (C) 2010 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 ResponsivenessTimer_h #define ResponsivenessTimer_h #include <wtf/RunLoop.h> namespace WebKit { class ResponsivenessTimer { public: class Client { public: virtual ~Client() { } virtual void didBecomeUnresponsive() = 0; virtual void didBecomeResponsive() = 0; virtual void willChangeIsResponsive() = 0; virtual void didChangeIsResponsive() = 0; virtual bool mayBecomeUnresponsive() = 0; virtual void ref() = 0; virtual void deref() = 0; }; explicit ResponsivenessTimer(ResponsivenessTimer::Client&); ~ResponsivenessTimer(); void start(); // A responsiveness timer with lazy stop does not stop the underlying system timer when stopped. // Instead, it ignores the timeout if stop() was already called. // // This exists to reduce the rate at which we reset the timer. // // With a non lazy timer, we may set a timer and reset it soon after because the process is responsive. // For events, this means reseting a timer 120 times/s for a 60 Hz event source. // By not reseting the timer when responsive, we cut that in half to 60 timeout changes. void startWithLazyStop(); void stop(); void invalidate(); // Return true if stop() was not called betfore the responsiveness timeout. bool isResponsive() const { return m_isResponsive; } // Return true if there is an active timer. The state could be responsive or not. bool hasActiveTimer() const { return m_waitingForTimer; } void processTerminated(); private: void timerFired(); ResponsivenessTimer::Client& m_client; RunLoop::Timer<ResponsivenessTimer> m_timer; MonotonicTime m_restartFireTime; bool m_isResponsive { true }; bool m_waitingForTimer { false }; bool m_useLazyStop { false }; }; } // namespace WebKit #endif // ResponsivenessTimer_h