1 /*        $NetBSD: schedule.c,v 1.8 2025/03/07 15:55:29 christos Exp $          */
2 
3 /*        $KAME: schedule.c,v 1.19 2001/11/05 10:53:19 sakane Exp $   */
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * Copyright (C) 2008 Timo Teras.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the project nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include "config.h"
36 
37 #include <sys/types.h>
38 #include <sys/param.h>
39 #include <sys/time.h>
40 #include <sys/queue.h>
41 #include <sys/socket.h>
42 
43 #include <stdlib.h>
44 #include <unistd.h>
45 #include <stdio.h>
46 #include <string.h>
47 #include <errno.h>
48 #include <time.h>
49 
50 #include "misc.h"
51 #include "plog.h"
52 #include "schedule.h"
53 #include "var.h"
54 #include "gcmalloc.h"
55 
56 #ifndef TAILQ_FOREACH
57 #define TAILQ_FOREACH(elm, head, field) \
58         for (elm = TAILQ_FIRST(head); elm; elm = TAILQ_NEXT(elm, field))
59 #endif
60 
61 static TAILQ_HEAD(_schedtree, sched) sctree;
62 
63 void
sched_get_monotonic_time(struct timeval * tv)64 sched_get_monotonic_time(struct timeval *tv)
65 {
66 #ifdef HAVE_CLOCK_MONOTONIC
67           struct timespec ts;
68 
69           clock_gettime(CLOCK_MONOTONIC, &ts);
70           tv->tv_sec = ts.tv_sec;
71           tv->tv_usec = ts.tv_nsec / 1000;
72 #else
73           gettimeofday(tv, NULL);
74 #endif
75 }
76 
77 /*ARGSUSED*/
78 time_t
sched_monotonic_to_time_t(struct timeval * tv,struct timeval * now __unused)79 sched_monotonic_to_time_t(struct timeval *tv, struct timeval *now __unused)
80 {
81 #ifdef HAVE_CLOCK_MONOTONIC
82           struct timeval mynow, res;
83 
84           if (now == NULL) {
85                     sched_get_monotonic_time(&mynow);
86                     now = &mynow;
87           }
88           timersub(now, tv, &res);
89 
90           return time(NULL) + res.tv_sec;
91 #else
92           return tv->tv_sec;
93 #endif
94 }
95 
96 /*
97  * schedule handler
98  * OUT:
99  *        time to block until next event.
100  *        if no entry, NULL returned.
101  */
102 struct timeval *
schedular()103 schedular()
104 {
105           static struct timeval timeout;
106           struct timeval now;
107           struct sched *p;
108 
109           sched_get_monotonic_time(&now);
110           while (!TAILQ_EMPTY(&sctree) &&
111                     timercmp(&TAILQ_FIRST(&sctree)->xtime, &now, <=)) {
112                     void (*func)(struct sched *);
113 
114                     p = TAILQ_FIRST(&sctree);
115                     func = p->func;
116                     sched_cancel(p);
117                     func(p);
118           }
119 
120           p = TAILQ_FIRST(&sctree);
121           if (p == NULL)
122                     return NULL;
123 
124           timersub(&p->xtime, &now, &timeout);
125 
126           return &timeout;
127 }
128 
129 /*
130  * add new schedule to schedule table.
131  */
132 void
sched_schedule(struct sched * sc,time_t tick,void (* func)(struct sched *))133 sched_schedule(struct sched *sc, time_t tick, void (*func)(struct sched *))
134 {
135           static long id = 1;
136           struct sched *p;
137           struct timeval now;
138 
139           sched_cancel(sc);
140 
141           sc->func = func;
142           sc->id = id++;
143           sc->tick.tv_sec = tick;
144           sc->tick.tv_usec = 0;
145           sched_get_monotonic_time(&now);
146           timeradd(&now, &sc->tick, &sc->xtime);
147 
148           /* add to schedule table */
149           TAILQ_FOREACH(p, &sctree, chain) {
150                     if (timercmp(&sc->xtime, &p->xtime, <))
151                               break;
152           }
153           if (p == NULL)
154                     TAILQ_INSERT_TAIL(&sctree, sc, chain);
155           else
156                     TAILQ_INSERT_BEFORE(p, sc, chain);
157 }
158 
159 /*
160  * cancel scheduled callback
161  */
162 void
sched_cancel(struct sched * sc)163 sched_cancel(struct sched *sc)
164 {
165           if (sc->func != NULL) {
166                     TAILQ_REMOVE(&sctree, sc, chain);
167                     sc->func = NULL;
168           }
169 }
170 
171 /*
172  * for debug
173  */
174 int
sched_dump(caddr_t * buf,int * len)175 sched_dump(caddr_t *buf, int *len)
176 {
177           caddr_t new;
178           struct sched *p;
179           struct scheddump *dst;
180           struct timeval now, created;
181           int cnt = 0;
182 
183           /* initialize */
184           *len = 0;
185           *buf = NULL;
186 
187           TAILQ_FOREACH(p, &sctree, chain)
188                     cnt++;
189 
190           /* no entry */
191           if (cnt == 0)
192                     return -1;
193 
194           *len = cnt * sizeof(*dst);
195 
196           new = racoon_malloc(*len);
197           if (new == NULL)
198                     return -1;
199           dst = (struct scheddump *)new;
200 
201           sched_get_monotonic_time(&now);
202           p = TAILQ_FIRST(&sctree);
203           while (p) {
204                     timersub(&p->xtime, &p->tick, &created);
205                     dst->xtime = p->xtime.tv_sec;
206                     dst->id = p->id;
207                     dst->created = sched_monotonic_to_time_t(&created, &now);
208                     dst->tick = p->tick.tv_sec;
209 
210                     p = TAILQ_NEXT(p, chain);
211                     if (p == NULL)
212                               break;
213                     dst++;
214           }
215 
216           *buf = new;
217 
218           return 0;
219 }
220 
221 /* initialize schedule table */
222 void
sched_init(void)223 sched_init(void)
224 {
225           TAILQ_INIT(&sctree);
226 }
227 
228 #ifdef STEST
229 #include <sys/types.h>
230 #include <sys/time.h>
231 #include <unistd.h>
232 #include <err.h>
233 
234 void
test(int * tick)235 test(int *tick)
236 {
237           printf("execute %d\n", *tick);
238           racoon_free(tick);
239 }
240 
241 void
getstdin(void)242 getstdin(void)
243 {
244           int *tick;
245           char buf[16];
246 
247           read(0, buf, sizeof(buf));
248           if (buf[0] == 'd') {
249                     struct scheddump *scbuf, *p;
250                     int len;
251                     sched_dump((caddr_t *)&scbuf, &len);
252                     if (scbuf == NULL)
253                               return;
254                     for (p = scbuf; len; p++) {
255                               printf("xtime=%ld\n", p->xtime);
256                               len -= sizeof(*p);
257                     }
258                     racoon_free(scbuf);
259                     return;
260           }
261 
262           tick = (int *)racoon_malloc(sizeof(*tick));
263           *tick = atoi(buf);
264           printf("new queue tick = %d\n", *tick);
265           sched_new(*tick, test, tick);
266 }
267 
268 int
main(void)269 main(void)
270 {
271           static fd_set mask0;
272           int nfds = 0;
273           fd_set rfds;
274           struct timeval *timeout;
275           int error;
276 
277           FD_ZERO(&mask0);
278           FD_SET(0, &mask0);
279           nfds = 1;
280 
281           /* initialize */
282           sched_init();
283 
284           while (1) {
285                     rfds = mask0;
286 
287                     timeout = schedular();
288 
289                     error = select(nfds, &rfds, (fd_set *)0, (fd_set *)0, timeout);
290                     if (error < 0) {
291                               switch (errno) {
292                               case EINTR: continue;
293                               default:
294                                         err(1, "select");
295                               }
296                               /*NOTREACHED*/
297                     }
298 
299                     if (FD_ISSET(0, &rfds))
300                               getstdin();
301           }
302 }
303 #endif
304