soft_timer.hpp

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/*
 *     SocialLedge.com - Copyright (C) 2013
 *
 *     This file is part of free software framework for embedded processors.
 *     You can use it and/or distribute it as long as this copyright header
 *     remains unmodified.  The code is free for personal use and requires
 *     permission to use in a commercial product.
 *
 *      THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
 *      OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
 *      MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
 *      I SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR
 *      CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
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 *     You can reach the author of this software at :
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 */

#ifndef SOFT_TIMER_H__
#define SOFT_TIMER_H__

#include <stdint.h>
#include "lpc_sys.h"



class SoftTimer
{
    public:
        SoftTimer() : mTargetMs(0), mIntervalMs(0) {}

        SoftTimer(uint32_t ms) : mTargetMs(0), mIntervalMs(0) { reset(ms); }

        inline bool expired(void) const
        { return (0 == mIntervalMs) ? false : ( getCurrentTimeMs() >= mTargetMs); }

        inline void restart(void) { mTargetMs += mIntervalMs; };

        inline void reset(uint64_t ms) { mIntervalMs = ms; mTargetMs = getCurrentTimeMs() + ms; }

        inline void reset(void) { mTargetMs = getCurrentTimeMs() + mIntervalMs; }

        inline void stop(void) { mIntervalMs = mTargetMs = 0; }

        inline bool isRunning(void) const { return (mIntervalMs > 0); }

        inline uint64_t getTimerValueMs(void) const { return mIntervalMs; }

        inline uint64_t getTargetTimerValueMs(void) const { return mTargetMs; }

        inline uint64_t getTimeToExpirationMs(void) const
        {
            uint64_t now = getCurrentTimeMs();
            const bool isExpired = (now >= mTargetMs);
            return isExpired ? 0 : (mTargetMs - now);
        }

        inline uint64_t getTimeSinceExpirationMs(void) const
        {
            uint64_t now = getCurrentTimeMs();
            const bool isExpired = (now >= mTargetMs);
            return isExpired ? (now - mTargetMs) : 0;
        }

        static inline uint64_t getCurrentTimeMs(void) { return sys_get_uptime_ms(); }

    protected:
        uint64_t mTargetMs;     
        uint64_t mIntervalMs;   

};




#ifdef TESTING
static inline void test_soft_timer_file(void)
{
    SoftTimer t;
    assert(!t.expired());
    assert(!t.isRunning());

    t.reset(); assert(!t.expired());
    t.reset(10); assert(!t.expired());
    delay_ms(8); assert(!t.expired());
    delay_ms(3); assert(t.expired());
    t.reset(); assert(!t.expired());
    delay_ms(8); assert(!t.expired());
    delay_ms(3); assert(t.expired());
    assert(t.isRunning());
    assert(10 == t.getTimerValueMs());

    t.reset(5); assert(5 == t.getTimeToExpirationMs());
    delay_ms(10); assert(5 == t.getTimeSinceExpirationMs());
}
#endif /* #ifdef TESTING */



#endif /* SOFT_TIMER_H__ */