1 /* $FreeBSD$ */ 2 /* $KAME: timer.c,v 1.9 2002/06/10 19:59:47 itojun 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/time.h> 34 35 #include <unistd.h> 36 #include <syslog.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <search.h> 40 #include "timer.h" 41 42 static struct rtadvd_timer timer_head; 43 44 #define MILLION 1000000 45 #define TIMEVAL_EQUAL(t1,t2) ((t1)->tv_sec == (t2)->tv_sec &&\ 46 (t1)->tv_usec == (t2)->tv_usec) 47 48 static struct timeval tm_max = {0x7fffffff, 0x7fffffff}; 49 50 void 51 rtadvd_timer_init() 52 { 53 memset(&timer_head, 0, sizeof(timer_head)); 54 55 timer_head.next = timer_head.prev = &timer_head; 56 timer_head.tm = tm_max; 57 } 58 59 struct rtadvd_timer * 60 rtadvd_add_timer(struct rtadvd_timer *(*timeout)(void *), 61 void (*update)(void *, struct timeval *), 62 void *timeodata, void *updatedata) 63 { 64 struct rtadvd_timer *newtimer; 65 66 if ((newtimer = malloc(sizeof(*newtimer))) == NULL) { 67 syslog(LOG_ERR, 68 "<%s> can't allocate memory", __func__); 69 exit(1); 70 } 71 72 memset(newtimer, 0, sizeof(*newtimer)); 73 74 if (timeout == NULL) { 75 syslog(LOG_ERR, 76 "<%s> timeout function unspecified", __func__); 77 exit(1); 78 } 79 newtimer->expire = timeout; 80 newtimer->update = update; 81 newtimer->expire_data = timeodata; 82 newtimer->update_data = updatedata; 83 newtimer->tm = tm_max; 84 85 /* link into chain */ 86 insque(newtimer, &timer_head); 87 88 return(newtimer); 89 } 90 91 void 92 rtadvd_remove_timer(struct rtadvd_timer **timer) 93 { 94 remque(*timer); 95 free(*timer); 96 *timer = NULL; 97 } 98 99 void 100 rtadvd_set_timer(struct timeval *tm, struct rtadvd_timer *timer) 101 { 102 struct timeval now; 103 104 /* reset the timer */ 105 gettimeofday(&now, NULL); 106 107 TIMEVAL_ADD(&now, tm, &timer->tm); 108 109 /* update the next expiration time */ 110 if (TIMEVAL_LT(timer->tm, timer_head.tm)) 111 timer_head.tm = timer->tm; 112 113 return; 114 } 115 116 /* 117 * Check expiration for each timer. If a timer expires, 118 * call the expire function for the timer and update the timer. 119 * Return the next interval for select() call. 120 */ 121 struct timeval * 122 rtadvd_check_timer() 123 { 124 static struct timeval returnval; 125 struct timeval now; 126 struct rtadvd_timer *tm = timer_head.next, *tm_next; 127 128 gettimeofday(&now, NULL); 129 130 timer_head.tm = tm_max; 131 132 for (tm = timer_head.next; tm != &timer_head; tm = tm_next) { 133 tm_next = tm->next; 134 135 if (TIMEVAL_LEQ(tm->tm, now)) { 136 if (((*tm->expire)(tm->expire_data) == NULL)) 137 continue; /* the timer was removed */ 138 if (tm->update) 139 (*tm->update)(tm->update_data, &tm->tm); 140 TIMEVAL_ADD(&tm->tm, &now, &tm->tm); 141 } 142 143 if (TIMEVAL_LT(tm->tm, timer_head.tm)) 144 timer_head.tm = tm->tm; 145 } 146 147 if (TIMEVAL_EQUAL(&tm_max, &timer_head.tm)) { 148 /* no need to timeout */ 149 return(NULL); 150 } else if (TIMEVAL_LT(timer_head.tm, now)) { 151 /* this may occur when the interval is too small */ 152 returnval.tv_sec = returnval.tv_usec = 0; 153 } else 154 TIMEVAL_SUB(&timer_head.tm, &now, &returnval); 155 return(&returnval); 156 } 157 158 struct timeval * 159 rtadvd_timer_rest(struct rtadvd_timer *timer) 160 { 161 static struct timeval returnval, now; 162 163 gettimeofday(&now, NULL); 164 if (TIMEVAL_LEQ(timer->tm, now)) { 165 syslog(LOG_DEBUG, 166 "<%s> a timer must be expired, but not yet", 167 __func__); 168 returnval.tv_sec = returnval.tv_usec = 0; 169 } 170 else 171 TIMEVAL_SUB(&timer->tm, &now, &returnval); 172 173 return(&returnval); 174 } 175 176 /* result = a + b */ 177 void 178 TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result) 179 { 180 long l; 181 182 if ((l = a->tv_usec + b->tv_usec) < MILLION) { 183 result->tv_usec = l; 184 result->tv_sec = a->tv_sec + b->tv_sec; 185 } 186 else { 187 result->tv_usec = l - MILLION; 188 result->tv_sec = a->tv_sec + b->tv_sec + 1; 189 } 190 } 191 192 /* 193 * result = a - b 194 * XXX: this function assumes that a >= b. 195 */ 196 void 197 TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result) 198 { 199 long l; 200 201 if ((l = a->tv_usec - b->tv_usec) >= 0) { 202 result->tv_usec = l; 203 result->tv_sec = a->tv_sec - b->tv_sec; 204 } 205 else { 206 result->tv_usec = MILLION + l; 207 result->tv_sec = a->tv_sec - b->tv_sec - 1; 208 } 209 } 210