Eliminate some dead initialization.
[dragonfly.git] / usr.sbin / rtadvd / timer.c
blob44d440832ef834dfec1d55e049cc658c37a6831c
1 /* $KAME: timer.c,v 1.4 2000/05/27 11:30:43 jinmei Exp $ */
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.
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.
31 * $FreeBSD: src/usr.sbin/rtadvd/timer.c,v 1.1.2.3 2002/06/29 18:59:53 ume Exp $
32 * $DragonFly: src/usr.sbin/rtadvd/timer.c,v 1.5 2005/12/05 00:56:37 swildner Exp $
35 #include <sys/time.h>
37 #include <unistd.h>
38 #include <syslog.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #if defined(__NetBSD__) || defined(__OpenBSD__)
42 #include <search.h>
43 #endif
44 #include "timer.h"
46 static struct rtadvd_timer timer_head;
48 #define MILLION 1000000
49 #define TIMEVAL_EQUAL(t1,t2) ((t1)->tv_sec == (t2)->tv_sec &&\
50 (t1)->tv_usec == (t2)->tv_usec)
52 static struct timeval tm_max = {0x7fffffff, 0x7fffffff};
54 void
55 rtadvd_timer_init(void)
57 memset(&timer_head, 0, sizeof(timer_head));
59 timer_head.next = timer_head.prev = &timer_head;
60 timer_head.tm = tm_max;
63 struct rtadvd_timer *
64 rtadvd_add_timer(struct rtadvd_timer *(*timeout)(void *),
65 void (*update)(void *, struct timeval *),
66 void *timeodata, void *updatedata)
68 struct rtadvd_timer *newtimer;
70 if ((newtimer = malloc(sizeof(*newtimer))) == NULL) {
71 syslog(LOG_ERR,
72 "<%s> can't allocate memory", __func__);
73 exit(1);
76 memset(newtimer, 0, sizeof(*newtimer));
78 if (timeout == NULL) {
79 syslog(LOG_ERR,
80 "<%s> timeout function unspecfied", __func__);
81 exit(1);
83 newtimer->expire = timeout;
84 newtimer->update = update;
85 newtimer->expire_data = timeodata;
86 newtimer->update_data = updatedata;
87 newtimer->tm = tm_max;
89 /* link into chain */
90 insque(newtimer, &timer_head);
92 return(newtimer);
95 void
96 rtadvd_remove_timer(struct rtadvd_timer **timer)
98 remque(*timer);
99 free(*timer);
100 *timer = NULL;
103 void
104 rtadvd_set_timer(struct timeval *tm, struct rtadvd_timer *timer)
106 struct timeval now;
108 /* reset the timer */
109 gettimeofday(&now, NULL);
111 TIMEVAL_ADD(&now, tm, &timer->tm);
113 /* update the next expiration time */
114 if (TIMEVAL_LT(timer->tm, timer_head.tm))
115 timer_head.tm = timer->tm;
117 return;
121 * Check expiration for each timer. If a timer expires,
122 * call the expire function for the timer and update the timer.
123 * Return the next interval for select() call.
125 struct timeval *
126 rtadvd_check_timer(void)
128 static struct timeval returnval;
129 struct timeval now;
130 struct rtadvd_timer *tm = timer_head.next, *tm_next;
132 gettimeofday(&now, NULL);
134 timer_head.tm = tm_max;
136 for (tm = timer_head.next; tm != &timer_head; tm = tm_next) {
137 tm_next = tm->next;
139 if (TIMEVAL_LEQ(tm->tm, now)) {
140 if (((*tm->expire)(tm->expire_data) == NULL))
141 continue; /* the timer was removed */
142 if (tm->update)
143 (*tm->update)(tm->update_data, &tm->tm);
144 TIMEVAL_ADD(&tm->tm, &now, &tm->tm);
147 if (TIMEVAL_LT(tm->tm, timer_head.tm))
148 timer_head.tm = tm->tm;
151 if (TIMEVAL_EQUAL(&tm_max, &timer_head.tm)) {
152 /* no need to timeout */
153 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;
159 else
160 TIMEVAL_SUB(&timer_head.tm, &now, &returnval);
161 return(&returnval);
164 struct timeval *
165 rtadvd_timer_rest(struct rtadvd_timer *timer)
167 static struct timeval returnval, now;
169 gettimeofday(&now, NULL);
170 if (TIMEVAL_LEQ(timer->tm, now)) {
171 syslog(LOG_DEBUG,
172 "<%s> a timer must be expired, but not yet",
173 __func__);
174 returnval.tv_sec = returnval.tv_usec = 0;
176 else
177 TIMEVAL_SUB(&timer->tm, &now, &returnval);
179 return(&returnval);
182 /* result = a + b */
183 void
184 TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result)
186 long l;
188 if ((l = a->tv_usec + b->tv_usec) < MILLION) {
189 result->tv_usec = l;
190 result->tv_sec = a->tv_sec + b->tv_sec;
192 else {
193 result->tv_usec = l - MILLION;
194 result->tv_sec = a->tv_sec + b->tv_sec + 1;
199 * result = a - b
200 * XXX: this function assumes that a >= b.
202 void
203 TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result)
205 long l;
207 if ((l = a->tv_usec - b->tv_usec) >= 0) {
208 result->tv_usec = l;
209 result->tv_sec = a->tv_sec - b->tv_sec;
211 else {
212 result->tv_usec = MILLION + l;
213 result->tv_sec = a->tv_sec - b->tv_sec - 1;