1 /* $NetBSD: timer.c,v 1.6 2002/05/21 14:29:53 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 #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(void (*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", __FUNCTION__); 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", __FUNCTION__); 79 exit(1); 80 } 81 if (update == NULL) { 82 syslog(LOG_ERR, 83 "<%s> update function unspecified", __FUNCTION__); 84 exit(1); 85 } 86 newtimer->expire = timeout; 87 newtimer->update = update; 88 newtimer->expire_data = timeodata; 89 newtimer->update_data = updatedata; 90 newtimer->tm = tm_max; 91 92 /* link into chain */ 93 insque(newtimer, &timer_head); 94 95 return(newtimer); 96 } 97 98 void 99 rtadvd_remove_timer(struct rtadvd_timer **timer) 100 { 101 remque(*timer); 102 free(*timer); 103 *timer = NULL; 104 } 105 106 void 107 rtadvd_set_timer(struct timeval *tm, struct rtadvd_timer *timer) 108 { 109 struct timeval now; 110 111 /* reset the timer */ 112 gettimeofday(&now, NULL); 113 114 TIMEVAL_ADD(&now, tm, &timer->tm); 115 116 /* update the next expiration time */ 117 if (TIMEVAL_LT(timer->tm, timer_head.tm)) 118 timer_head.tm = timer->tm; 119 120 return; 121 } 122 123 /* 124 * Check expiration for each timer. If a timer is expired, 125 * call the expire function for the timer and update the timer. 126 * Return the next interval for select() call. 127 */ 128 struct timeval * 129 rtadvd_check_timer() 130 { 131 static struct timeval returnval; 132 struct timeval now; 133 struct rtadvd_timer *tm = timer_head.next; 134 135 gettimeofday(&now, NULL); 136 137 timer_head.tm = tm_max; 138 139 while (tm != &timer_head) { 140 if (TIMEVAL_LEQ(tm->tm, now)) { 141 (*tm->expire)(tm->expire_data); 142 (*tm->update)(tm->update_data, &tm->tm); 143 TIMEVAL_ADD(&tm->tm, &now, &tm->tm); 144 } 145 146 if (TIMEVAL_LT(tm->tm, timer_head.tm)) 147 timer_head.tm = tm->tm; 148 149 tm = tm->next; 150 } 151 152 if (TIMEVAL_EQUAL(&tm_max, &timer_head.tm)) { 153 /* no need to timeout */ 154 return(NULL); 155 } else if (TIMEVAL_LT(timer_head.tm, now)) { 156 /* this may occur when the interval is too small */ 157 returnval.tv_sec = returnval.tv_usec = 0; 158 } else 159 TIMEVAL_SUB(&timer_head.tm, &now, &returnval); 160 return(&returnval); 161 } 162 163 struct timeval * 164 rtadvd_timer_rest(struct rtadvd_timer *timer) 165 { 166 static struct timeval returnval, now; 167 168 gettimeofday(&now, NULL); 169 if (TIMEVAL_LEQ(timer->tm, now)) { 170 syslog(LOG_DEBUG, 171 "<%s> a timer must be expired, but not yet", 172 __FUNCTION__); 173 returnval.tv_sec = returnval.tv_usec = 0; 174 } 175 else 176 TIMEVAL_SUB(&timer->tm, &now, &returnval); 177 178 return(&returnval); 179 } 180 181 /* result = a + b */ 182 void 183 TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result) 184 { 185 long l; 186 187 if ((l = a->tv_usec + b->tv_usec) < MILLION) { 188 result->tv_usec = l; 189 result->tv_sec = a->tv_sec + b->tv_sec; 190 } 191 else { 192 result->tv_usec = l - MILLION; 193 result->tv_sec = a->tv_sec + b->tv_sec + 1; 194 } 195 } 196 197 /* 198 * result = a - b 199 * XXX: this function assumes that a >= b. 200 */ 201 void 202 TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result) 203 { 204 long l; 205 206 if ((l = a->tv_usec - b->tv_usec) >= 0) { 207 result->tv_usec = l; 208 result->tv_sec = a->tv_sec - b->tv_sec; 209 } 210 else { 211 result->tv_usec = MILLION + l; 212 result->tv_sec = a->tv_sec - b->tv_sec - 1; 213 } 214 } 215