266 lines
6.8 KiB
C
266 lines
6.8 KiB
C
/**
|
|
* \addtogroup etimer
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* Event 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: etimer.c,v 1.2 2006/10/09 16:05:58 nifi Exp $
|
|
*/
|
|
|
|
#include "contiki-conf.h"
|
|
|
|
#include "sys/etimer.h"
|
|
#include "sys/process.h"
|
|
|
|
static struct etimer *timerlist;
|
|
static clock_time_t next_expiration;
|
|
|
|
PROCESS(etimer_process, "Event timer");
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
update_time(void)
|
|
{
|
|
clock_time_t nextt;
|
|
clock_time_t now;
|
|
struct etimer *t;
|
|
|
|
if (timerlist == NULL) {
|
|
next_expiration = 0;
|
|
} else {
|
|
now = clock_time();
|
|
t = timerlist;
|
|
/* Must take current time into account due to wraps */
|
|
nextt = t->timer.start + t->timer.interval - now;
|
|
for(t = t->next; t != NULL; t = t->next) {
|
|
if(t->timer.start + t->timer.interval - now < nextt) {
|
|
nextt = t->timer.start + t->timer.interval - now;
|
|
}
|
|
}
|
|
next_expiration = nextt + now;
|
|
}
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
PROCESS_THREAD(etimer_process, ev, data)
|
|
{
|
|
struct etimer *t, *u;
|
|
|
|
PROCESS_BEGIN();
|
|
|
|
timerlist = NULL;
|
|
|
|
while(1) {
|
|
PROCESS_YIELD();
|
|
|
|
if(ev == PROCESS_EVENT_EXITED) {
|
|
struct process *p = data;
|
|
|
|
while(timerlist != NULL && timerlist->p == p) {
|
|
timerlist = timerlist->next;
|
|
}
|
|
|
|
if(timerlist != NULL) {
|
|
t = timerlist;
|
|
while(t->next != NULL) {
|
|
if(t->next->p == p) {
|
|
t->next = t->next->next;
|
|
} else
|
|
t = t->next;
|
|
}
|
|
}
|
|
continue;
|
|
} else if(ev != PROCESS_EVENT_POLL) {
|
|
continue;
|
|
}
|
|
|
|
again:
|
|
|
|
u = NULL;
|
|
|
|
for(t = timerlist; t != NULL; t = t->next) {
|
|
if(timer_expired(&t->timer)) {
|
|
if(process_post(t->p, PROCESS_EVENT_TIMER, t) == PROCESS_ERR_OK) {
|
|
|
|
/* Reset the process ID of the event timer, to signal that the
|
|
etimer has expired. This is later checked in the
|
|
etimer_expired() function. */
|
|
t->p = PROCESS_NONE;
|
|
if(u != NULL) {
|
|
u->next = t->next;
|
|
} else {
|
|
timerlist = t->next;
|
|
}
|
|
t->next = NULL;
|
|
update_time();
|
|
goto again;
|
|
} else {
|
|
etimer_request_poll();
|
|
}
|
|
}
|
|
u = t;
|
|
}
|
|
|
|
}
|
|
|
|
PROCESS_END();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
etimer_request_poll(void)
|
|
{
|
|
process_poll(&etimer_process);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
add_timer(struct etimer *timer)
|
|
{
|
|
struct etimer *t;
|
|
|
|
etimer_request_poll();
|
|
|
|
if(timer->p != PROCESS_NONE) {
|
|
/* Timer not on list. */
|
|
|
|
for(t = timerlist; t != NULL; t = t->next) {
|
|
if(t == timer) {
|
|
/* Timer already on list, bail out. */
|
|
update_time();
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
timer->p = PROCESS_CURRENT();
|
|
timer->next = timerlist;
|
|
timerlist = timer;
|
|
|
|
update_time();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
etimer_set(struct etimer *et, clock_time_t interval)
|
|
{
|
|
timer_set(&et->timer, interval);
|
|
add_timer(et);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
etimer_reset(struct etimer *et)
|
|
{
|
|
timer_reset(&et->timer);
|
|
add_timer(et);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
etimer_restart(struct etimer *et)
|
|
{
|
|
timer_restart(&et->timer);
|
|
add_timer(et);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
etimer_adjust(struct etimer *et, int timediff)
|
|
{
|
|
et->timer.start += timediff;
|
|
update_time();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
int
|
|
etimer_expired(struct etimer *et)
|
|
{
|
|
return et->p == PROCESS_NONE;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
clock_time_t
|
|
etimer_expiration_time(struct etimer *et)
|
|
{
|
|
return et->timer.start + et->timer.interval;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
clock_time_t
|
|
etimer_start_time(struct etimer *et)
|
|
{
|
|
return et->timer.start;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
int
|
|
etimer_pending(void)
|
|
{
|
|
return timerlist != NULL;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
clock_time_t
|
|
etimer_next_expiration_time(void)
|
|
{
|
|
return etimer_pending() ? next_expiration : 0;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
etimer_stop(struct etimer *et)
|
|
{
|
|
struct etimer *t;
|
|
|
|
/* First check if et is the first event timer on the list. */
|
|
if(et == timerlist) {
|
|
timerlist = timerlist->next;
|
|
update_time();
|
|
} else {
|
|
/* Else walk through the list and try to find the item before the
|
|
et timer. */
|
|
for(t = timerlist; t != NULL && t->next != et; t = t->next);
|
|
|
|
if(t != NULL) {
|
|
/* We've found the item before the event timer that we are about
|
|
to remove. We point the items next pointer to the event after
|
|
the removed item. */
|
|
t->next = et->next;
|
|
|
|
update_time();
|
|
}
|
|
}
|
|
|
|
/* Remove the next pointer from the item to be removed. */
|
|
et->next = NULL;
|
|
/* Set the timer as expired */
|
|
et->p = PROCESS_NONE;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/** @} */
|