1 /* $NetBSD: timer.c,v 1.3 2000/05/23 11:37:59 itojun Exp $ */ 2 /* $KAME: timer.c,v 1.3 2000/05/22 22:23:07 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 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", __FUNCTION__); 69 exit(1); 70 } 71 72 memset(newtimer, 0, sizeof(*newtimer)); 73 74 if (timeout == NULL) { 75 syslog(LOG_ERR, 76 "<%s> timeout function unspecfied", __FUNCTION__); 77 exit(1); 78 } 79 if (update == NULL) { 80 syslog(LOG_ERR, 81 "<%s> update function unspecfied", __FUNCTION__); 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_set_timer(struct timeval *tm, struct rtadvd_timer *timer) 98 { 99 struct timeval now; 100 101 /* reset the timer */ 102 gettimeofday(&now, NULL); 103 104 TIMEVAL_ADD(&now, tm, &timer->tm); 105 106 /* update the next expiration time */ 107 if (TIMEVAL_LT(timer->tm, timer_head.tm)) 108 timer_head.tm = timer->tm; 109 110 return; 111 } 112 113 /* 114 * Check expiration for each timer. If a timer is expired, 115 * call the expire function for the timer and update the timer. 116 * Return the next interval for select() call. 117 */ 118 struct timeval * 119 rtadvd_check_timer() 120 { 121 static struct timeval returnval; 122 struct timeval now; 123 struct rtadvd_timer *tm = timer_head.next; 124 125 gettimeofday(&now, NULL); 126 127 timer_head.tm = tm_max; 128 129 while(tm != &timer_head) { 130 if (TIMEVAL_LEQ(tm->tm, now)) { 131 (*tm->expire)(tm->expire_data); 132 (*tm->update)(tm->update_data, &tm->tm); 133 TIMEVAL_ADD(&tm->tm, &now, &tm->tm); 134 } 135 136 if (TIMEVAL_LT(tm->tm, timer_head.tm)) 137 timer_head.tm = tm->tm; 138 139 tm = tm->next; 140 } 141 142 if (TIMEVAL_LT(timer_head.tm, now)) { 143 /* this may occur when the interval is too small */ 144 returnval.tv_sec = returnval.tv_usec = 0; 145 } 146 else 147 TIMEVAL_SUB(&timer_head.tm, &now, &returnval); 148 return(&returnval); 149 } 150 151 struct timeval * 152 rtadvd_timer_rest(struct rtadvd_timer *timer) 153 { 154 static struct timeval returnval, now; 155 156 gettimeofday(&now, NULL); 157 if (TIMEVAL_LEQ(timer->tm, now)) { 158 syslog(LOG_DEBUG, 159 "<%s> a timer must be expired, but not yet", 160 __FUNCTION__); 161 returnval.tv_sec = returnval.tv_usec = 0; 162 } 163 else 164 TIMEVAL_SUB(&timer->tm, &now, &returnval); 165 166 return(&returnval); 167 } 168 169 /* result = a + b */ 170 void 171 TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result) 172 { 173 long l; 174 175 if ((l = a->tv_usec + b->tv_usec) < MILLION) { 176 result->tv_usec = l; 177 result->tv_sec = a->tv_sec + b->tv_sec; 178 } 179 else { 180 result->tv_usec = l - MILLION; 181 result->tv_sec = a->tv_sec + b->tv_sec + 1; 182 } 183 } 184 185 /* 186 * result = a - b 187 * XXX: this function assumes that a >= b. 188 */ 189 void 190 TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result) 191 { 192 long l; 193 194 if ((l = a->tv_usec - b->tv_usec) >= 0) { 195 result->tv_usec = l; 196 result->tv_sec = a->tv_sec - b->tv_sec; 197 } 198 else { 199 result->tv_usec = MILLION + l; 200 result->tv_sec = a->tv_sec - b->tv_sec - 1; 201 } 202 } 203