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 #if defined(__NetBSD__) || defined(__OpenBSD__) 40 #include <search.h> 41 #endif 42 #include "timer.h" 43 44 static struct rtadvd_timer timer_head; 45 46 #define MILLION 1000000 47 #define TIMEVAL_EQUAL(t1,t2) ((t1)->tv_sec == (t2)->tv_sec &&\ 48 (t1)->tv_usec == (t2)->tv_usec) 49 50 static struct timeval tm_max = {0x7fffffff, 0x7fffffff}; 51 52 void 53 rtadvd_timer_init() 54 { 55 memset(&timer_head, 0, sizeof(timer_head)); 56 57 timer_head.next = timer_head.prev = &timer_head; 58 timer_head.tm = tm_max; 59 } 60 61 struct rtadvd_timer * 62 rtadvd_add_timer(struct rtadvd_timer *(*timeout) __P((void *)), 63 void (*update) __P((void *, struct timeval *)), 64 void *timeodata, void *updatedata) 65 { 66 struct rtadvd_timer *newtimer; 67 68 if ((newtimer = malloc(sizeof(*newtimer))) == NULL) { 69 syslog(LOG_ERR, 70 "<%s> can't allocate memory", __func__); 71 exit(1); 72 } 73 74 memset(newtimer, 0, sizeof(*newtimer)); 75 76 if (timeout == NULL) { 77 syslog(LOG_ERR, 78 "<%s> timeout function unspecified", __func__); 79 exit(1); 80 } 81 newtimer->expire = timeout; 82 newtimer->update = update; 83 newtimer->expire_data = timeodata; 84 newtimer->update_data = updatedata; 85 newtimer->tm = tm_max; 86 87 /* link into chain */ 88 insque(newtimer, &timer_head); 89 90 return(newtimer); 91 } 92 93 void 94 rtadvd_remove_timer(struct rtadvd_timer **timer) 95 { 96 remque(*timer); 97 free(*timer); 98 *timer = NULL; 99 } 100 101 void 102 rtadvd_set_timer(struct timeval *tm, struct rtadvd_timer *timer) 103 { 104 struct timeval now; 105 106 /* reset the timer */ 107 gettimeofday(&now, NULL); 108 109 TIMEVAL_ADD(&now, tm, &timer->tm); 110 111 /* update the next expiration time */ 112 if (TIMEVAL_LT(timer->tm, timer_head.tm)) 113 timer_head.tm = timer->tm; 114 115 return; 116 } 117 118 /* 119 * Check expiration for each timer. If a timer expires, 120 * call the expire function for the timer and update the timer. 121 * Return the next interval for select() call. 122 */ 123 struct timeval * 124 rtadvd_check_timer() 125 { 126 static struct timeval returnval; 127 struct timeval now; 128 struct rtadvd_timer *tm = timer_head.next, *tm_next; 129 130 gettimeofday(&now, NULL); 131 132 timer_head.tm = tm_max; 133 134 for (tm = timer_head.next; tm != &timer_head; tm = tm_next) { 135 tm_next = tm->next; 136 137 if (TIMEVAL_LEQ(tm->tm, now)) { 138 if (((*tm->expire)(tm->expire_data) == NULL)) 139 continue; /* the timer was removed */ 140 if (tm->update) 141 (*tm->update)(tm->update_data, &tm->tm); 142 TIMEVAL_ADD(&tm->tm, &now, &tm->tm); 143 } 144 145 if (TIMEVAL_LT(tm->tm, timer_head.tm)) 146 timer_head.tm = tm->tm; 147 } 148 149 if (TIMEVAL_EQUAL(&tm_max, &timer_head.tm)) { 150 /* no need to timeout */ 151 return(NULL); 152 } else if (TIMEVAL_LT(timer_head.tm, now)) { 153 /* this may occur when the interval is too small */ 154 returnval.tv_sec = returnval.tv_usec = 0; 155 } else 156 TIMEVAL_SUB(&timer_head.tm, &now, &returnval); 157 return(&returnval); 158 } 159 160 struct timeval * 161 rtadvd_timer_rest(struct rtadvd_timer *timer) 162 { 163 static struct timeval returnval, now; 164 165 gettimeofday(&now, NULL); 166 if (TIMEVAL_LEQ(timer->tm, now)) { 167 syslog(LOG_DEBUG, 168 "<%s> a timer must be expired, but not yet", 169 __func__); 170 returnval.tv_sec = returnval.tv_usec = 0; 171 } 172 else 173 TIMEVAL_SUB(&timer->tm, &now, &returnval); 174 175 return(&returnval); 176 } 177 178 /* result = a + b */ 179 void 180 TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result) 181 { 182 long l; 183 184 if ((l = a->tv_usec + b->tv_usec) < MILLION) { 185 result->tv_usec = l; 186 result->tv_sec = a->tv_sec + b->tv_sec; 187 } 188 else { 189 result->tv_usec = l - MILLION; 190 result->tv_sec = a->tv_sec + b->tv_sec + 1; 191 } 192 } 193 194 /* 195 * result = a - b 196 * XXX: this function assumes that a >= b. 197 */ 198 void 199 TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result) 200 { 201 long l; 202 203 if ((l = a->tv_usec - b->tv_usec) >= 0) { 204 result->tv_usec = l; 205 result->tv_sec = a->tv_sec - b->tv_sec; 206 } 207 else { 208 result->tv_usec = MILLION + l; 209 result->tv_sec = a->tv_sec - b->tv_sec - 1; 210 } 211 } 212