Contiki-NG
timer.h
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1 /*
2  * Copyright (c) 2004, Swedish Institute of Computer Science.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the Institute nor the names of its contributors
14  * may be used to endorse or promote products derived from this software
15  * without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS AS IS'' AND
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23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * This file is part of the Contiki operating system.
30  *
32  *
33  */
34
35 /**
36  * \file
37  * Timer library header file.
38  * \author
40  */
41
42 /** \addtogroup timers
43  * @{ */
44
45 /**
46  * \defgroup timer Timer library
47  *
48  * The timer library provides functions for setting, resetting and
49  * restarting timers, and for checking if a timer has expired. An
50  * application must "manually" check if its timers have expired; this
51  * is not done automatically.
52  *
53  * A timer is declared as a \c struct \c timer and all access to the
54  * timer is made by a pointer to the declared timer.
55  *
56  * \note The timer library is not able to post events when a timer
57  * expires. The \ref etimer "Event timers" should be used for this
58  * purpose.
59  *
60  * \note The timer library uses the \ref clock "Clock library" to
61  * measure time. Intervals should be specified in the format used by
62  * the clock library.
63  *
64  * \sa \ref etimer "Event timers"
65  *
66  * @{
67  */
68
69 #ifndef TIMER_H_
70 #define TIMER_H_
71
72 #include "sys/clock.h"
73
74 /**
75  * A timer.
76  *
77  * This structure is used for declaring a timer. The timer must be set
78  * with timer_set() before it can be used.
79  *
80  * \hideinitializer
81  */
82 struct timer {
83  clock_time_t start;
84  clock_time_t interval;
85 };
86
87 void timer_set(struct timer *t, clock_time_t interval);
88 void timer_reset(struct timer *t);
89 void timer_restart(struct timer *t);
90 int timer_expired(struct timer *t);
91 clock_time_t timer_remaining(struct timer *t);
92
93
94 #endif /* TIMER_H_ */
95
96 /** @} */
97 /** @} */
void timer_set(struct timer *t, clock_time_t interval)
Set a timer.
Definition: timer.c:64
clock_time_t timer_remaining(struct timer *t)
The time until the timer expires.
Definition: timer.c:143
void timer_reset(struct timer *t)
Reset the timer with the same interval.
Definition: timer.c:84
A timer.
Definition: timer.h:82
void timer_restart(struct timer *t)
Restart the timer from the current point in time.
Definition: timer.c:106
int timer_expired(struct timer *t)
Check if a timer has expired.
Definition: timer.c:123