NetBSD/usr.sbin/rtadvd/timer.c

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/* $NetBSD: timer.c,v 1.2 1999/07/06 13:02:09 itojun Exp $ */
/*
* Copyright (C) 1998 WIDE Project.
* 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 project 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 PROJECT 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 PROJECT 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.
*/
#include <sys/time.h>
#include <unistd.h>
#include <syslog.h>
#include <stdlib.h>
#include <string.h>
#ifdef __NetBSD__
#include <search.h>
#endif
#include "timer.h"
static struct rtadvd_timer timer_head;
#define MILLION 1000000
static struct timeval tm_max = {0x7fffffff, 0x7fffffff};
void
rtadvd_timer_init()
{
memset(&timer_head, 0, sizeof(timer_head));
timer_head.next = timer_head.prev = &timer_head;
timer_head.tm = tm_max;
}
struct rtadvd_timer *
rtadvd_add_timer(void (*timeout) __P((void *)),
void (*update) __P((void *, struct timeval *)),
void *timeodata, void *updatedata)
{
struct rtadvd_timer *newtimer;
if ((newtimer = malloc(sizeof(*newtimer))) == NULL) {
syslog(LOG_ERR,
"<%s> can't allocate memory", __FUNCTION__);
exit(1);
}
memset(newtimer, 0, sizeof(*newtimer));
if (timeout == NULL) {
syslog(LOG_ERR,
"<%s> timeout function unspecfied", __FUNCTION__);
exit(1);
}
if (update == NULL) {
syslog(LOG_ERR,
"<%s> update function unspecfied", __FUNCTION__);
exit(1);
}
newtimer->expire = timeout;
newtimer->update = update;
newtimer->expire_data = timeodata;
newtimer->update_data = updatedata;
newtimer->tm = tm_max;
/* link into chain */
insque(newtimer, &timer_head);
return(newtimer);
}
void
rtadvd_set_timer(struct timeval *tm, struct rtadvd_timer *timer)
{
struct timeval now;
/* reset the timer */
gettimeofday(&now, NULL);
TIMEVAL_ADD(&now, tm, &timer->tm);
/* update the next expiration time */
if (TIMEVAL_LT(timer->tm, timer_head.tm))
timer_head.tm = timer->tm;
return;
}
/*
* Check expiration for each timer. If a timer is expired,
* call the expire function for the timer and update the timer.
* Return the next interval for select() call.
*/
struct timeval *
rtadvd_check_timer()
{
static struct timeval returnval;
struct timeval now;
struct rtadvd_timer *tm = timer_head.next;
gettimeofday(&now, NULL);
timer_head.tm = tm_max;
while(tm != &timer_head) {
if (TIMEVAL_LEQ(tm->tm, now)) {
(*tm->expire)(tm->expire_data);
(*tm->update)(tm->update_data, &tm->tm);
TIMEVAL_ADD(&tm->tm, &now, &tm->tm);
}
if (TIMEVAL_LT(tm->tm, timer_head.tm))
timer_head.tm = tm->tm;
tm = tm->next;
}
if (TIMEVAL_LT(timer_head.tm, now)) {
/* this may occur when the interval is too small */
returnval.tv_sec = returnval.tv_usec = 0;
}
else
TIMEVAL_SUB(&timer_head.tm, &now, &returnval);
return(&returnval);
}
struct timeval *
rtadvd_timer_rest(struct rtadvd_timer *timer)
{
static struct timeval returnval, now;
gettimeofday(&now, NULL);
if (TIMEVAL_LEQ(timer->tm, now)) {
syslog(LOG_DEBUG,
"<%s> a timer must be expired, but not yet",
__FUNCTION__);
returnval.tv_sec = returnval.tv_usec = 0;
}
else
TIMEVAL_SUB(&timer->tm, &now, &returnval);
return(&returnval);
}
/* result = a + b */
void
TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result)
{
long l;
if ((l = a->tv_usec + b->tv_usec) < MILLION) {
result->tv_usec = l;
result->tv_sec = a->tv_sec + b->tv_sec;
}
else {
result->tv_usec = l - MILLION;
result->tv_sec = a->tv_sec + b->tv_sec + 1;
}
}
/*
* result = a - b
* XXX: this function assumes that a >= b.
*/
void
TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result)
{
long l;
if ((l = a->tv_usec - b->tv_usec) >= 0) {
result->tv_usec = l;
result->tv_sec = a->tv_sec - b->tv_sec;
}
else {
result->tv_usec = MILLION + l;
result->tv_sec = a->tv_sec - b->tv_sec - 1;
}
}