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 1.1.2.3 2002/06/29 18:59:53 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 #include <search.h> 41 #include "timer.h" 42 43 static struct rtadvd_timer timer_head; 44 45 #define MILLION 1000000 46 #define TIMEVAL_EQUAL(t1,t2) ((t1)->tv_sec == (t2)->tv_sec &&\ 47 (t1)->tv_usec == (t2)->tv_usec) 48 49 static struct timeval tm_max = {0x7fffffff, 0x7fffffff}; 50 51 void 52 rtadvd_timer_init(void) 53 { 54 memset(&timer_head, 0, sizeof(timer_head)); 55 56 timer_head.next = timer_head.prev = &timer_head; 57 timer_head.tm = tm_max; 58 } 59 60 struct rtadvd_timer * 61 rtadvd_add_timer(struct rtadvd_timer *(*timeout)(void *), 62 void (*update)(void *, struct timeval *), 63 void *timeodata, void *updatedata) 64 { 65 struct rtadvd_timer *newtimer; 66 67 if ((newtimer = malloc(sizeof(*newtimer))) == NULL) { 68 syslog(LOG_ERR, 69 "<%s> can't allocate memory", __func__); 70 exit(1); 71 } 72 73 memset(newtimer, 0, sizeof(*newtimer)); 74 75 if (timeout == NULL) { 76 syslog(LOG_ERR, 77 "<%s> timeout function unspecfied", __func__); 78 exit(1); 79 } 80 newtimer->expire = timeout; 81 newtimer->update = update; 82 newtimer->expire_data = timeodata; 83 newtimer->update_data = updatedata; 84 newtimer->tm = tm_max; 85 86 /* link into chain */ 87 insque(newtimer, &timer_head); 88 89 return(newtimer); 90 } 91 92 void 93 rtadvd_remove_timer(struct rtadvd_timer **timer) 94 { 95 remque(*timer); 96 free(*timer); 97 *timer = NULL; 98 } 99 100 void 101 rtadvd_set_timer(struct timeval *tm, struct rtadvd_timer *timer) 102 { 103 struct timeval now; 104 105 /* reset the timer */ 106 gettimeofday(&now, NULL); 107 108 TIMEVAL_ADD(&now, tm, &timer->tm); 109 110 /* update the next expiration time */ 111 if (TIMEVAL_LT(timer->tm, timer_head.tm)) 112 timer_head.tm = timer->tm; 113 114 return; 115 } 116 117 /* 118 * Check expiration for each timer. If a timer expires, 119 * call the expire function for the timer and update the timer. 120 * Return the next interval for select() call. 121 */ 122 struct timeval * 123 rtadvd_check_timer(void) 124 { 125 static struct timeval returnval; 126 struct timeval now; 127 struct rtadvd_timer *tm = timer_head.next, *tm_next; 128 129 gettimeofday(&now, NULL); 130 131 timer_head.tm = tm_max; 132 133 for (tm = timer_head.next; tm != &timer_head; tm = tm_next) { 134 tm_next = tm->next; 135 136 if (TIMEVAL_LEQ(tm->tm, now)) { 137 if (((*tm->expire)(tm->expire_data) == NULL)) 138 continue; /* the timer was removed */ 139 if (tm->update) 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 } 147 148 if (TIMEVAL_EQUAL(&tm_max, &timer_head.tm)) { 149 /* no need to timeout */ 150 return(NULL); 151 } 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 } 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