1 /* $NetBSD: timer.c,v 1.8 2002/07/10 21:11:44 itojun Exp $ */ 2 /* $KAME: timer.c,v 1.6 2002/05/15 08:53:07 jinmei 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(void (*timeout) __P((void *)), 61 void (*update) __P((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 if (update == NULL) { 80 syslog(LOG_ERR, 81 "<%s> update function unspecified", __func__); 82 exit(1); 83 } 84 newtimer->expire = timeout; 85 newtimer->update = update; 86 newtimer->expire_data = timeodata; 87 newtimer->update_data = updatedata; 88 newtimer->tm = tm_max; 89 90 /* link into chain */ 91 insque(newtimer, &timer_head); 92 93 return(newtimer); 94 } 95 96 void 97 rtadvd_remove_timer(struct rtadvd_timer **timer) 98 { 99 remque(*timer); 100 free(*timer); 101 *timer = NULL; 102 } 103 104 void 105 rtadvd_set_timer(struct timeval *tm, struct rtadvd_timer *timer) 106 { 107 struct timeval now; 108 109 /* reset the timer */ 110 gettimeofday(&now, NULL); 111 112 TIMEVAL_ADD(&now, tm, &timer->tm); 113 114 /* update the next expiration time */ 115 if (TIMEVAL_LT(timer->tm, timer_head.tm)) 116 timer_head.tm = timer->tm; 117 118 return; 119 } 120 121 /* 122 * Check expiration for each timer. If a timer is expired, 123 * call the expire function for the timer and update the timer. 124 * Return the next interval for select() call. 125 */ 126 struct timeval * 127 rtadvd_check_timer() 128 { 129 static struct timeval returnval; 130 struct timeval now; 131 struct rtadvd_timer *tm = timer_head.next; 132 133 gettimeofday(&now, NULL); 134 135 timer_head.tm = tm_max; 136 137 while (tm != &timer_head) { 138 if (TIMEVAL_LEQ(tm->tm, now)) { 139 (*tm->expire)(tm->expire_data); 140 (*tm->update)(tm->update_data, &tm->tm); 141 TIMEVAL_ADD(&tm->tm, &now, &tm->tm); 142 } 143 144 if (TIMEVAL_LT(tm->tm, timer_head.tm)) 145 timer_head.tm = tm->tm; 146 147 tm = tm->next; 148 } 149 150 if (TIMEVAL_EQUAL(&tm_max, &timer_head.tm)) { 151 /* no need to timeout */ 152 return(NULL); 153 } else if (TIMEVAL_LT(timer_head.tm, now)) { 154 /* this may occur when the interval is too small */ 155 returnval.tv_sec = returnval.tv_usec = 0; 156 } else 157 TIMEVAL_SUB(&timer_head.tm, &now, &returnval); 158 return(&returnval); 159 } 160 161 struct timeval * 162 rtadvd_timer_rest(struct rtadvd_timer *timer) 163 { 164 static struct timeval returnval, now; 165 166 gettimeofday(&now, NULL); 167 if (TIMEVAL_LEQ(timer->tm, now)) { 168 syslog(LOG_DEBUG, 169 "<%s> a timer must be expired, but not yet", 170 __func__); 171 returnval.tv_sec = returnval.tv_usec = 0; 172 } 173 else 174 TIMEVAL_SUB(&timer->tm, &now, &returnval); 175 176 return(&returnval); 177 } 178 179 /* result = a + b */ 180 void 181 TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result) 182 { 183 long l; 184 185 if ((l = a->tv_usec + b->tv_usec) < MILLION) { 186 result->tv_usec = l; 187 result->tv_sec = a->tv_sec + b->tv_sec; 188 } 189 else { 190 result->tv_usec = l - MILLION; 191 result->tv_sec = a->tv_sec + b->tv_sec + 1; 192 } 193 } 194 195 /* 196 * result = a - b 197 * XXX: this function assumes that a >= b. 198 */ 199 void 200 TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result) 201 { 202 long l; 203 204 if ((l = a->tv_usec - b->tv_usec) >= 0) { 205 result->tv_usec = l; 206 result->tv_sec = a->tv_sec - b->tv_sec; 207 } 208 else { 209 result->tv_usec = MILLION + l; 210 result->tv_sec = a->tv_sec - b->tv_sec - 1; 211 } 212 } 213