8 * Timer library implementation.
\r
10 * Adam Dunkels <adam@sics.se>
\r
14 * Copyright (c) 2004, Swedish Institute of Computer Science.
\r
15 * All rights reserved.
\r
17 * Redistribution and use in source and binary forms, with or without
\r
18 * modification, are permitted provided that the following conditions
\r
20 * 1. Redistributions of source code must retain the above copyright
\r
21 * notice, this list of conditions and the following disclaimer.
\r
22 * 2. Redistributions in binary form must reproduce the above copyright
\r
23 * notice, this list of conditions and the following disclaimer in the
\r
24 * documentation and/or other materials provided with the distribution.
\r
25 * 3. Neither the name of the Institute nor the names of its contributors
\r
26 * may be used to endorse or promote products derived from this software
\r
27 * without specific prior written permission.
\r
29 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
\r
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
\r
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
\r
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
\r
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
\r
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
\r
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
\r
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
\r
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
\r
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
\r
41 * This file is part of the uIP TCP/IP stack
\r
43 * Author: Adam Dunkels <adam@sics.se>
\r
45 * $Id: timer.c,v 1.2 2006/06/12 08:00:30 adam Exp $
\r
48 #include "uip_timer.h"
\r
50 /*---------------------------------------------------------------------------*/
\r
55 * This function is used to set a timer for a time sometime in the
\r
56 * future. The function timer_expired() will evaluate to true after
\r
57 * the timer has expired.
\r
59 * \param t A pointer to the timer
\r
60 * \param interval The interval before the timer expires.
\r
63 void timer_set( struct timer *t, clock_time_t interval )
\r
65 t->interval = interval;
\r
66 t->start = clock_time();
\r
69 /*---------------------------------------------------------------------------*/
\r
72 * Reset the timer with the same interval.
\r
74 * This function resets the timer with the same interval that was
\r
75 * given to the timer_set() function. The start point of the interval
\r
76 * is the exact time that the timer last expired. Therefore, this
\r
77 * function will cause the timer to be stable over time, unlike the
\r
78 * timer_rester() function.
\r
80 * \param t A pointer to the timer.
\r
82 * \sa timer_restart()
\r
84 void timer_reset( struct timer *t )
\r
86 t->start += t->interval;
\r
89 /*---------------------------------------------------------------------------*/
\r
92 * Restart the timer from the current point in time
\r
94 * This function restarts a timer with the same interval that was
\r
95 * given to the timer_set() function. The timer will start at the
\r
98 * \note A periodic timer will drift if this function is used to reset
\r
99 * it. For preioric timers, use the timer_reset() function instead.
\r
101 * \param t A pointer to the timer.
\r
103 * \sa timer_reset()
\r
105 void timer_restart( struct timer *t )
\r
107 t->start = clock_time();
\r
110 /*---------------------------------------------------------------------------*/
\r
113 * Check if a timer has expired.
\r
115 * This function tests if a timer has expired and returns true or
\r
116 * false depending on its status.
\r
118 * \param t A pointer to the timer
\r
120 * \return Non-zero if the timer has expired, zero otherwise.
\r
123 int timer_expired( struct timer *t )
\r
125 return( clock_time_t ) ( clock_time() - t->start ) >= ( clock_time_t ) t->interval;
\r
128 /*---------------------------------------------------------------------------*/
\r