/* * Copyright (C) 2011 Google 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 CCDelayBasedTimeSource_h #define CCDelayBasedTimeSource_h #include "cc/CCTimeSource.h" #include "cc/CCTimer.h" #include <wtf/PassRefPtr.h> namespace WebCore { class CCThread; // This timer implements a time source that achieves the specified interval // in face of millisecond-precision delayed callbacks and random queueing delays. class CCDelayBasedTimeSource : public CCTimeSource, CCTimerClient { public: static PassRefPtr<CCDelayBasedTimeSource> create(double intervalSeconds, CCThread*); virtual ~CCDelayBasedTimeSource() { } virtual void setClient(CCTimeSourceClient* client) OVERRIDE { m_client = client; } virtual void setActive(bool) OVERRIDE; virtual bool active() const OVERRIDE { return m_state != STATE_INACTIVE; } // CCTimerClient implementation. virtual void onTimerFired() OVERRIDE; // Virtual for testing. virtual double monotonicallyIncreasingTime() const; protected: CCDelayBasedTimeSource(double interval, CCThread*); void postNextTickTask(double now); enum State { STATE_INACTIVE, STATE_STARTING, STATE_ACTIVE, }; CCTimeSourceClient* m_client; bool m_hasTickTarget; double m_intervalSeconds; double m_tickTarget; State m_state; CCThread* m_thread; CCTimer m_timer; }; } #endif // CCDelayBasedTimeSource_h