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timer.c revision 1.15 
      1 /*	$NetBSD: timer.c,v 1.15 2018/04/20 10:39:37 roy Exp $	*/
      2 /*	$KAME: timer.c,v 1.11 2005/04/14 06:22:35 suz Exp $	*/
      3 
      4 /*
      5  * Copyright (C) 1998 WIDE Project.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of the project nor the names of its contributors
     17  *    may be used to endorse or promote products derived from this software
     18  *    without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
     21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
     24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     30  * SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/queue.h>
     34 #include <sys/time.h>
     35 
     36 #include <limits.h>
     37 #include <unistd.h>
     38 #include <syslog.h>
     39 #include <stdlib.h>
     40 #include <string.h>
     41 #include <search.h>
     42 #include "timer.h"
     43 #include "logit.h"
     44 #include "prog_ops.h"
     45 
     46 struct rtadvd_timer_head_t ra_timer = TAILQ_HEAD_INITIALIZER(ra_timer);
     47 static struct timespec tm_limit = { LONG_MAX, 1000000000L - 1 };
     48 static struct timespec tm_max;
     49 
     50 void
     51 rtadvd_timer_init(void)
     52 {
     53 
     54 	TAILQ_INIT(&ra_timer);
     55 	tm_max = tm_limit;
     56 }
     57 
     58 struct rtadvd_timer *
     59 rtadvd_add_timer(struct rtadvd_timer *(*timeout) (void *),
     60     void (*update) (void *, struct timespec *),
     61     void *timeodata, void *updatedata)
     62 {
     63 	struct rtadvd_timer *newtimer;
     64 
     65 	if ((newtimer = malloc(sizeof(*newtimer))) == NULL) {
     66 		logit(LOG_ERR,
     67 		       "<%s> can't allocate memory", __func__);
     68 		exit(1);
     69 	}
     70 
     71 	memset(newtimer, 0, sizeof(*newtimer));
     72 
     73 	if (timeout == NULL) {
     74 		logit(LOG_ERR,
     75 		       "<%s> timeout function unspecified", __func__);
     76 		exit(1);
     77 	}
     78 	newtimer->expire = timeout;
     79 	newtimer->update = update;
     80 	newtimer->expire_data = timeodata;
     81 	newtimer->update_data = updatedata;
     82 	newtimer->tm = tm_max;
     83 
     84 	/* link into chain */
     85 	TAILQ_INSERT_TAIL(&ra_timer, newtimer, next);
     86 
     87 	return(newtimer);
     88 }
     89 
     90 void
     91 rtadvd_remove_timer(struct rtadvd_timer **timer)
     92 {
     93 
     94 	if (*timer) {
     95 		TAILQ_REMOVE(&ra_timer, *timer, next);
     96 		free(*timer);
     97 		*timer = NULL;
     98 	}
     99 }
    100 
    101 void
    102 rtadvd_set_timer(struct timespec *tm, struct rtadvd_timer *timer)
    103 {
    104 	struct timespec now;
    105 
    106 	/* reset the timer */
    107 	prog_clock_gettime(CLOCK_MONOTONIC, &now);
    108 	timespecadd(&now, tm, &timer->tm);
    109 
    110 	/* upate the next expiration time */
    111 	if (timespeccmp(&timer->tm, &tm_max, <))
    112 		tm_max = timer->tm;
    113 }
    114 
    115 /*
    116  * Check expiration for each timer. If a timer expires,
    117  * call the expire function for the timer and update the timer.
    118  * Return the next interval for select() call.
    119  */
    120 struct timespec *
    121 rtadvd_check_timer(void)
    122 {
    123 	static struct timespec returnval;
    124 	struct timespec now;
    125 	struct rtadvd_timer *tm, *tmn;
    126 
    127 	prog_clock_gettime(CLOCK_MONOTONIC, &now);
    128 	tm_max = tm_limit;
    129 
    130 	TAILQ_FOREACH_SAFE(tm, &ra_timer, next, tmn) {
    131 		if (timespeccmp(&tm->tm, &now, <=)) {
    132 			if ((*tm->expire)(tm->expire_data) == NULL)
    133 				continue; /* the timer was removed */
    134 			if (tm->update)
    135 				(*tm->update)(tm->update_data, &tm->tm);
    136 			timespecadd(&tm->tm, &now, &tm->tm);
    137 		}
    138 		if (timespeccmp(&tm->tm, &tm_max, <))
    139 			tm_max = tm->tm;
    140 	}
    141 
    142 	if (timespeccmp(&tm_max, &tm_limit, ==))
    143 		return(NULL);
    144 	if (timespeccmp(&tm_max, &now, <)) {
    145 		/* this may occur when the interval is too small */
    146 		timespecclear(&returnval);
    147 	} else
    148 		timespecsub(&tm_max, &now, &returnval);
    149 	return(&returnval);
    150 }
    151 
    152 struct timespec *
    153 rtadvd_timer_rest(struct rtadvd_timer *timer)
    154 {
    155 	static struct timespec returnval;
    156 	struct timespec now;
    157 
    158 	prog_clock_gettime(CLOCK_MONOTONIC, &now);
    159 	if (timespeccmp(&timer->tm, &now, <=)) {
    160 		logit(LOG_DEBUG,
    161 		       "<%s> a timer must be expired, but not yet",
    162 		       __func__);
    163 		returnval.tv_sec = 0;
    164 		returnval.tv_nsec = 0;
    165 	}
    166 	else
    167 		timespecsub(&timer->tm, &now, &returnval);
    168 
    169 	return(&returnval);
    170 }
    171