/*

 * Copyright (C) 2006 Apple Computer, 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 COMPUTER, 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 COMPUTER, 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 Timer_h

#define Timer_h

#include <wtf/Noncopyable.h>

#include <wtf/Threading.h>

namespace WebCore {

// Time intervals are all in seconds.

class TimerHeapElement;

class TimerBase : public Noncopyable {

public:

    TimerBase();

    virtual ~TimerBase();

    void start(double nextFireInterval, double repeatInterval);

    void startRepeating(double repeatInterval) { start(repeatInterval, repeatInterval); }

    void startOneShot(double interval) { start(interval, 0); }

    void stop();

    bool isActive() const;

    double nextFireInterval() const;

    double repeatInterval() const { return m_repeatInterval; }

    void augmentRepeatInterval(double delta) { setNextFireTime(m_nextFireTime + delta); m_repeatInterval += delta; }

    static void fireTimersInNestedEventLoop();

private:

    virtual void fired() = 0;

    void checkConsistency() const;

    void checkHeapIndex() const;

    void setNextFireTime(double);

    bool inHeap() const { return m_heapIndex != -1; }

    void heapDecreaseKey();

    void heapDelete();

    void heapDeleteMin();

    void heapIncreaseKey();

    void heapInsert();

    void heapPop();

    void heapPopMin();

    double m_nextFireTime; // 0 if inactive

    double m_repeatInterval; // 0 if not repeating

    int m_heapIndex; // -1 if not in heap

    unsigned m_heapInsertionOrder; // Used to keep order among equal-fire-time timers

#ifndef NDEBUG

    ThreadIdentifier m_thread;

#endif

    friend class TimerHeapElement;

    friend class ThreadTimers;

    friend bool operator<(const TimerHeapElement&, const TimerHeapElement&);

};

template <typename TimerFiredClass> class Timer : public TimerBase {

public:

    typedef void (TimerFiredClass::*TimerFiredFunction)(Timer*);

    Timer(TimerFiredClass* o, TimerFiredFunction f)

        : m_object(o), m_function(f) { }

private:

    virtual void fired() { (m_object->*m_function)(this); }

    TimerFiredClass* m_object;

    TimerFiredFunction m_function;

};

inline bool TimerBase::isActive() const

{

    ASSERT(m_thread == currentThread());

    return m_nextFireTime;

}

}

#endif