rtadvd.tproj/timer.c

   1 /*      $KAME: timer.c,v 1.4 2000/05/27 11:30:43 jinmei Exp $   */
   2
   3 /*
   4  * Copyright (C) 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD: src/usr.sbin/rtadvd/timer.c,v 1.1.2.2 2001/07/03 11:02:14 ume Exp $
  32  */
  33
  34 #include <sys/time.h>
  35
  36 #include <unistd.h>
  37 #include <syslog.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #if defined(__NetBSD__) || defined(__OpenBSD__)
  41 #include <search.h>
  42 #endif
  43 #include "timer.h"
  44
  45 static struct rtadvd_timer timer_head;
  46
  47 #define MILLION 1000000
  48 #define TIMEVAL_EQUAL(t1,t2) ((t1)->tv_sec == (t2)->tv_sec &&\
  49  (t1)->tv_usec == (t2)->tv_usec)
  50
  51 static struct timeval tm_max = {0x7fffffff, 0x7fffffff};
  52
  53 void
  54 rtadvd_timer_init()
  55 {
  56         memset(&timer_head, 0, sizeof(timer_head));
  57
  58         timer_head.next = timer_head.prev = &timer_head;
  59         timer_head.tm = tm_max;
  60 }
  61
  62 struct rtadvd_timer *
  63 rtadvd_add_timer(void (*timeout) __P((void *)),
  64                 void (*update) __P((void *, struct timeval *)),
  65                  void *timeodata, void *updatedata)
  66 {
  67         struct rtadvd_timer *newtimer;
  68
  69         if ((newtimer = malloc(sizeof(*newtimer))) == NULL) {
  70                 syslog(LOG_ERR,
  71                        "<%s> can't allocate memory", __FUNCTION__);
  72                 exit(1);
  73         }
  74
  75         memset(newtimer, 0, sizeof(*newtimer));
  76
  77         if (timeout == NULL) {
  78                 syslog(LOG_ERR,
  79                        "<%s> timeout function unspecfied", __FUNCTION__);
  80                 exit(1);
  81         }
  82         if (update == NULL) {
  83                 syslog(LOG_ERR,
  84                        "<%s> update function unspecfied", __FUNCTION__);
  85                 exit(1);
  86         }
  87         newtimer->expire = timeout;
  88         newtimer->update = update;
  89         newtimer->expire_data = timeodata;
  90         newtimer->update_data = updatedata;
  91         newtimer->tm = tm_max;
  92
  93         /* link into chain */
  94         insque(newtimer, &timer_head);
  95
  96         return(newtimer);
  97 }
  98
  99 void
 100 rtadvd_remove_timer(struct rtadvd_timer **timer)
 101 {
 102         remque(*timer);
 103         free(*timer);
 104         *timer = NULL;
 105 }
 106
 107 void
 108 rtadvd_set_timer(struct timeval *tm, struct rtadvd_timer *timer)
 109 {
 110         struct timeval now;
 111
 112         /* reset the timer */
 113         gettimeofday(&now, NULL);
 114
 115         TIMEVAL_ADD(&now, tm, &timer->tm);
 116
 117         /* update the next expiration time */
 118         if (TIMEVAL_LT(timer->tm, timer_head.tm))
 119                 timer_head.tm = timer->tm;
 120
 121         return;
 122 }
 123
 124 /*
 125  * Check expiration for each timer. If a timer is expired,
 126  * call the expire function for the timer and update the timer.
 127  * Return the next interval for select() call.
 128  */
 129 struct timeval *
 130 rtadvd_check_timer()
 131 {
 132         static struct timeval returnval;
 133         struct timeval now;
 134         struct rtadvd_timer *tm = timer_head.next;
 135
 136         gettimeofday(&now, NULL);
 137
 138         timer_head.tm = tm_max;
 139
 140         while(tm != &timer_head) {
 141                 if (TIMEVAL_LEQ(tm->tm, now)) {
 142                         (*tm->expire)(tm->expire_data);
 143                         (*tm->update)(tm->update_data, &tm->tm);
 144                         TIMEVAL_ADD(&tm->tm, &now, &tm->tm);
 145                 }
 146
 147                 if (TIMEVAL_LT(tm->tm, timer_head.tm))
 148                         timer_head.tm = tm->tm;
 149
 150                 tm = tm->next;
 151         }
 152
 153         if (TIMEVAL_EQUAL(&tm_max, &timer_head.tm)) {
 154                 /* no need to timeout */
 155                 return(NULL);
 156         }
 157         else if (TIMEVAL_LT(timer_head.tm, now)) {
 158                 /* this may occur when the interval is too small */
 159                 returnval.tv_sec = returnval.tv_usec = 0;
 160         }
 161         else
 162                 TIMEVAL_SUB(&timer_head.tm, &now, &returnval);
 163         return(&returnval);
 164 }
 165
 166 struct timeval *
 167 rtadvd_timer_rest(struct rtadvd_timer *timer)
 168 {
 169         static struct timeval returnval, now;
 170
 171         gettimeofday(&now, NULL);
 172         if (TIMEVAL_LEQ(timer->tm, now)) {
 173                 syslog(LOG_DEBUG,
 174                        "<%s> a timer must be expired, but not yet",
 175                        __FUNCTION__);
 176                 returnval.tv_sec = returnval.tv_usec = 0;
 177         }
 178         else
 179                 TIMEVAL_SUB(&timer->tm, &now, &returnval);
 180
 181         return(&returnval);
 182 }
 183
 184 /* result = a + b */
 185 void
 186 TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result)
 187 {
 188         long l;
 189
 190         if ((l = a->tv_usec + b->tv_usec) < MILLION) {
 191                 result->tv_usec = l;
 192                 result->tv_sec = a->tv_sec + b->tv_sec;
 193         }
 194         else {
 195                 result->tv_usec = l - MILLION;
 196                 result->tv_sec = a->tv_sec + b->tv_sec + 1;
 197         }
 198 }
 199
 200 /*
 201  * result = a - b
 202  * XXX: this function assumes that a >= b.
 203  */
 204 void
 205 TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result)
 206 {
 207         long l;
 208
 209         if ((l = a->tv_usec - b->tv_usec) >= 0) {
 210                 result->tv_usec = l;
 211                 result->tv_sec = a->tv_sec - b->tv_sec;
 212         }
 213         else {
 214                 result->tv_usec = MILLION + l;
 215                 result->tv_sec = a->tv_sec - b->tv_sec - 1;
 216         }
 217 }