1 /*
2 * event.h
3 */
4
5 /*-
6 * SPDX-License-Identifier: BSD-2-Clause
7 *
8 * Copyright (c) 2009 Maksim Yevmenkin <m_evmenkin@yahoo.com>
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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
34 /*
35 * Hack to provide libevent (see devel/libevent port) like API.
36 * Should be removed if FreeBSD ever decides to import libevent into base.
37 */
38
39 #include <sys/select.h>
40 #include <sys/time.h>
41 #include <sys/queue.h>
42 #include <assert.h>
43 #include <stdarg.h>
44 #include <stdio.h>
45 #include <string.h>
46 #include <syslog.h>
47
48 #include "event.h"
49 #define L2CAP_SOCKET_CHECKED
50 #include "btpand.h"
51
52 #define __event_link(ev) \
53 do { \
54 TAILQ_INSERT_TAIL(&pending, ev, next); \
55 ev->flags |= EV_PENDING; \
56 } while (0)
57
58 static void tv_add(struct timeval *, struct timeval const *);
59 static void tv_sub(struct timeval *, struct timeval const *);
60 static int tv_cmp(struct timeval const *, struct timeval const *);
61 static int __event_dispatch(void);
62 static void __event_add_current(struct event *);
63 static void __event_del_current(struct event *);
64
65
66 static TAILQ_HEAD(, event) pending;
67 static TAILQ_HEAD(, event) current;
68
69 void
event_init(void)70 event_init(void)
71 {
72 TAILQ_INIT(&pending);
73 }
74
75 int
event_dispatch(void)76 event_dispatch(void)
77 {
78 while (__event_dispatch() == 0)
79 ;
80
81 return (-1);
82 }
83
84 static int
__event_dispatch(void)85 __event_dispatch(void)
86 {
87 fd_set r, w;
88 int nfd;
89 struct event *ev;
90 struct timeval now, timeout, t;
91
92 FD_ZERO(&r);
93 FD_ZERO(&w);
94
95 nfd = 0;
96
97 gettimeofday(&now, NULL);
98
99 timeout.tv_sec = 10; /* arbitrary */
100 timeout.tv_usec = 0;
101
102 TAILQ_INIT(¤t);
103
104 /*
105 * Build fd_set's
106 */
107
108 event_log_debug("%s: building fd set...", __func__);
109
110 while (!TAILQ_EMPTY(&pending)) {
111 ev = TAILQ_FIRST(&pending);
112 event_del(ev);
113
114 if (ev->flags & EV_HAS_TIMEOUT) {
115 if (tv_cmp(&now, &ev->expire) >= 0)
116 t.tv_sec = t.tv_usec = 0;
117 else {
118 t = ev->expire;
119 tv_sub(&t, &now);
120 }
121
122 if (tv_cmp(&t, &timeout) < 0)
123 timeout = t;
124 }
125
126 if (ev->fd >= 0) {
127 if (ev->flags & EV_READ) {
128 FD_SET(ev->fd, &r);
129 nfd = (nfd > ev->fd) ? nfd : ev->fd;
130 }
131
132 if (ev->flags & EV_WRITE) {
133 FD_SET(ev->fd, &w);
134 nfd = (nfd > ev->fd) ? nfd : ev->fd;
135 }
136 }
137
138 __event_add_current(ev);
139 }
140
141 event_log_debug("%s: waiting for events...", __func__);
142
143 nfd = select(nfd + 1, &r, &w, NULL, &timeout);
144 if (nfd < 0)
145 return (-1);
146
147 /*
148 * Process current pending
149 */
150
151 event_log_debug("%s: processing events...", __func__);
152
153 gettimeofday(&now, NULL);
154
155 while (!TAILQ_EMPTY(¤t)) {
156 ev = TAILQ_FIRST(¤t);
157 __event_del_current(ev);
158
159 /* check if fd is ready for reading/writing */
160 if (nfd > 0 && ev->fd >= 0) {
161 if (FD_ISSET(ev->fd, &r) || FD_ISSET(ev->fd, &w)) {
162 if (ev->flags & EV_PERSIST) {
163 if (ev->flags & EV_HAS_TIMEOUT)
164 event_add(ev, &ev->timeout);
165 else
166 event_add(ev, NULL);
167 }
168
169 nfd --;
170
171 event_log_debug("%s: calling %p(%d, %p), " \
172 "ev=%p", __func__, ev->cb, ev->fd,
173 ev->cbarg, ev);
174
175 (ev->cb)(ev->fd,
176 (ev->flags & (EV_READ|EV_WRITE)),
177 ev->cbarg);
178
179 continue;
180 }
181 }
182
183 /* if event has no timeout - just requeue */
184 if ((ev->flags & EV_HAS_TIMEOUT) == 0) {
185 event_add(ev, NULL);
186 continue;
187 }
188
189 /* check if event has expired */
190 if (tv_cmp(&now, &ev->expire) >= 0) {
191 if (ev->flags & EV_PERSIST)
192 event_add(ev, &ev->timeout);
193
194 event_log_debug("%s: calling %p(%d, %p), ev=%p",
195 __func__, ev->cb, ev->fd, ev->cbarg, ev);
196
197 (ev->cb)(ev->fd,
198 (ev->flags & (EV_READ|EV_WRITE)),
199 ev->cbarg);
200
201 continue;
202 }
203
204 assert((ev->flags & (EV_PENDING|EV_CURRENT)) == 0);
205 __event_link(ev);
206 }
207
208 return (0);
209 }
210
211 void
__event_set(struct event * ev,int fd,short flags,void (* cb)(int,short,void *),void * cbarg)212 __event_set(struct event *ev, int fd, short flags,
213 void (*cb)(int, short, void *), void *cbarg)
214 {
215 ev->fd = fd;
216 ev->flags = flags;
217 ev->cb = cb;
218 ev->cbarg = cbarg;
219 }
220
221 int
__event_add(struct event * ev,const struct timeval * timeout)222 __event_add(struct event *ev, const struct timeval *timeout)
223 {
224 assert((ev->flags & (EV_PENDING|EV_CURRENT)) == 0);
225
226 if (timeout != NULL) {
227 gettimeofday(&ev->expire, NULL);
228 tv_add(&ev->expire, timeout);
229 ev->timeout = *timeout;
230 ev->flags |= EV_HAS_TIMEOUT;
231 } else
232 ev->flags &= ~EV_HAS_TIMEOUT;
233
234 __event_link(ev);
235
236 return (0);
237 }
238
239 int
__event_del(struct event * ev)240 __event_del(struct event *ev)
241 {
242 assert((ev->flags & EV_CURRENT) == 0);
243
244 if ((ev->flags & EV_PENDING) != 0) {
245 TAILQ_REMOVE(&pending, ev, next);
246 ev->flags &= ~EV_PENDING;
247 }
248
249 return (0);
250 }
251
252 static void
__event_add_current(struct event * ev)253 __event_add_current(struct event *ev)
254 {
255 assert((ev->flags & (EV_PENDING|EV_CURRENT)) == 0);
256
257 TAILQ_INSERT_TAIL(¤t, ev, next);
258 ev->flags |= EV_CURRENT;
259 }
260
261 static void
__event_del_current(struct event * ev)262 __event_del_current(struct event *ev)
263 {
264 assert((ev->flags & (EV_CURRENT|EV_PENDING)) == EV_CURRENT);
265
266 TAILQ_REMOVE(¤t, ev, next);
267 ev->flags &= ~EV_CURRENT;
268 }
269
270 static void
tv_add(struct timeval * a,struct timeval const * b)271 tv_add(struct timeval *a, struct timeval const *b)
272 {
273 a->tv_sec += b->tv_sec;
274 a->tv_usec += b->tv_usec;
275
276 if(a->tv_usec >= 1000000) {
277 a->tv_usec -= 1000000;
278 a->tv_sec += 1;
279 }
280 }
281
282 static void
tv_sub(struct timeval * a,struct timeval const * b)283 tv_sub(struct timeval *a, struct timeval const *b)
284 {
285 if (a->tv_usec < b->tv_usec) {
286 a->tv_usec += 1000000;
287 a->tv_sec -= 1;
288 }
289
290 a->tv_usec -= b->tv_usec;
291 a->tv_sec -= b->tv_sec;
292 }
293
294 static int
tv_cmp(struct timeval const * a,struct timeval const * b)295 tv_cmp(struct timeval const *a, struct timeval const *b)
296 {
297 if (a->tv_sec > b->tv_sec)
298 return (1);
299
300 if (a->tv_sec < b->tv_sec)
301 return (-1);
302
303 if (a->tv_usec > b->tv_usec)
304 return (1);
305
306 if (a->tv_usec < b->tv_usec)
307 return (-1);
308
309 return (0);
310 }
311
312