129 lines
4.0 KiB
C
129 lines
4.0 KiB
C
/**
|
|
* \addtogroup timer
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* Timer library implementation.
|
|
* \author
|
|
* Adam Dunkels <adam@sics.se>
|
|
*/
|
|
|
|
/*
|
|
* Copyright (c) 2004, Swedish Institute of Computer Science.
|
|
* 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.
|
|
* 3. Neither the name of the Institute nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND 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 THE INSTITUTE 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.
|
|
*
|
|
* This file is part of the Contiki operating system.
|
|
*
|
|
* Author: Adam Dunkels <adam@sics.se>
|
|
*
|
|
* $Id: timer.c,v 1.2 2007/05/27 11:11:28 oliverschmidt Exp $
|
|
*/
|
|
|
|
#include "contiki-conf.h"
|
|
#include "sys/clock.h"
|
|
#include "sys/timer.h"
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* Set a timer.
|
|
*
|
|
* This function is used to set a timer for a time sometime in the
|
|
* future. The function timer_expired() will evaluate to true after
|
|
* the timer has expired.
|
|
*
|
|
* \param t A pointer to the timer
|
|
* \param interval The interval before the timer expires.
|
|
*
|
|
*/
|
|
void
|
|
timer_set(struct timer *t, clock_time_t interval)
|
|
{
|
|
t->interval = interval;
|
|
t->start = clock_time();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* Reset the timer with the same interval.
|
|
*
|
|
* This function resets the timer with the same interval that was
|
|
* given to the timer_set() function. The start point of the interval
|
|
* is the exact time that the timer last expired. Therefore, this
|
|
* function will cause the timer to be stable over time, unlike the
|
|
* timer_restart() function.
|
|
*
|
|
* \param t A pointer to the timer.
|
|
*
|
|
* \sa timer_restart()
|
|
*/
|
|
void
|
|
timer_reset(struct timer *t)
|
|
{
|
|
t->start += t->interval;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* Restart the timer from the current point in time
|
|
*
|
|
* This function restarts a timer with the same interval that was
|
|
* given to the timer_set() function. The timer will start at the
|
|
* current time.
|
|
*
|
|
* \note A periodic timer will drift if this function is used to reset
|
|
* it. For preioric timers, use the timer_reset() function instead.
|
|
*
|
|
* \param t A pointer to the timer.
|
|
*
|
|
* \sa timer_reset()
|
|
*/
|
|
void
|
|
timer_restart(struct timer *t)
|
|
{
|
|
t->start = clock_time();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* Check if a timer has expired.
|
|
*
|
|
* This function tests if a timer has expired and returns true or
|
|
* false depending on its status.
|
|
*
|
|
* \param t A pointer to the timer
|
|
*
|
|
* \return Non-zero if the timer has expired, zero otherwise.
|
|
*
|
|
*/
|
|
int
|
|
timer_expired(struct timer *t)
|
|
{
|
|
return (clock_time_t)(clock_time() - t->start) >= (clock_time_t)t->interval;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
|
|
/** @} */
|