1 /* 2 * event.h 3 */ 4 5 /*- 6 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 /* $FreeBSD$ */ 34 35 /* 36 * Hack to provide libevent (see devel/libevent port) like API. 37 * Should be removed if FreeBSD ever decides to import libevent into base. 38 */ 39 40 #include <sys/select.h> 41 #include <sys/time.h> 42 #include <sys/queue.h> 43 #include <assert.h> 44 #include <stdarg.h> 45 #include <stdio.h> 46 #include <string.h> 47 #include <syslog.h> 48 49 #include "event.h" 50 #define L2CAP_SOCKET_CHECKED 51 #include "btpand.h" 52 53 #define __event_link(ev) \ 54 do { \ 55 TAILQ_INSERT_TAIL(&pending, ev, next); \ 56 ev->flags |= EV_PENDING; \ 57 } while (0) 58 59 static void tv_add(struct timeval *, struct timeval const *); 60 static void tv_sub(struct timeval *, struct timeval const *); 61 static int tv_cmp(struct timeval const *, struct timeval const *); 62 static int __event_dispatch(void); 63 static void __event_add_current(struct event *); 64 static void __event_del_current(struct event *); 65 66 67 static TAILQ_HEAD(, event) pending; 68 static TAILQ_HEAD(, event) current; 69 70 void 71 event_init(void) 72 { 73 TAILQ_INIT(&pending); 74 } 75 76 int 77 event_dispatch(void) 78 { 79 while (__event_dispatch() == 0) 80 ; 81 82 return (-1); 83 } 84 85 static int 86 __event_dispatch(void) 87 { 88 fd_set r, w; 89 int nfd; 90 struct event *ev; 91 struct timeval now, timeout, t; 92 93 FD_ZERO(&r); 94 FD_ZERO(&w); 95 96 nfd = 0; 97 98 gettimeofday(&now, NULL); 99 100 timeout.tv_sec = 10; /* arbitrary */ 101 timeout.tv_usec = 0; 102 103 TAILQ_INIT(¤t); 104 105 /* 106 * Build fd_set's 107 */ 108 109 event_log_debug("%s: building fd set...", __func__); 110 111 while (!TAILQ_EMPTY(&pending)) { 112 ev = TAILQ_FIRST(&pending); 113 event_del(ev); 114 115 if (ev->flags & EV_HAS_TIMEOUT) { 116 if (tv_cmp(&now, &ev->expire) >= 0) 117 t.tv_sec = t.tv_usec = 0; 118 else { 119 t = ev->expire; 120 tv_sub(&t, &now); 121 } 122 123 if (tv_cmp(&t, &timeout) < 0) 124 timeout = t; 125 } 126 127 if (ev->fd >= 0) { 128 if (ev->flags & EV_READ) { 129 FD_SET(ev->fd, &r); 130 nfd = (nfd > ev->fd) ? nfd : ev->fd; 131 } 132 133 if (ev->flags & EV_WRITE) { 134 FD_SET(ev->fd, &w); 135 nfd = (nfd > ev->fd) ? nfd : ev->fd; 136 } 137 } 138 139 __event_add_current(ev); 140 } 141 142 event_log_debug("%s: waiting for events...", __func__); 143 144 nfd = select(nfd + 1, &r, &w, NULL, &timeout); 145 if (nfd < 0) 146 return (-1); 147 148 /* 149 * Process current pending 150 */ 151 152 event_log_debug("%s: processing events...", __func__); 153 154 gettimeofday(&now, NULL); 155 156 while (!TAILQ_EMPTY(¤t)) { 157 ev = TAILQ_FIRST(¤t); 158 __event_del_current(ev); 159 160 /* check if fd is ready for reading/writing */ 161 if (nfd > 0 && ev->fd >= 0) { 162 if (FD_ISSET(ev->fd, &r) || FD_ISSET(ev->fd, &w)) { 163 if (ev->flags & EV_PERSIST) { 164 if (ev->flags & EV_HAS_TIMEOUT) 165 event_add(ev, &ev->timeout); 166 else 167 event_add(ev, NULL); 168 } 169 170 nfd --; 171 172 event_log_debug("%s: calling %p(%d, %p), " \ 173 "ev=%p", __func__, ev->cb, ev->fd, 174 ev->cbarg, ev); 175 176 (ev->cb)(ev->fd, 177 (ev->flags & (EV_READ|EV_WRITE)), 178 ev->cbarg); 179 180 continue; 181 } 182 } 183 184 /* if event has no timeout - just requeue */ 185 if ((ev->flags & EV_HAS_TIMEOUT) == 0) { 186 event_add(ev, NULL); 187 continue; 188 } 189 190 /* check if event has expired */ 191 if (tv_cmp(&now, &ev->expire) >= 0) { 192 if (ev->flags & EV_PERSIST) 193 event_add(ev, &ev->timeout); 194 195 event_log_debug("%s: calling %p(%d, %p), ev=%p", 196 __func__, ev->cb, ev->fd, ev->cbarg, ev); 197 198 (ev->cb)(ev->fd, 199 (ev->flags & (EV_READ|EV_WRITE)), 200 ev->cbarg); 201 202 continue; 203 } 204 205 assert((ev->flags & (EV_PENDING|EV_CURRENT)) == 0); 206 __event_link(ev); 207 } 208 209 return (0); 210 } 211 212 void 213 __event_set(struct event *ev, int fd, short flags, 214 void (*cb)(int, short, void *), void *cbarg) 215 { 216 ev->fd = fd; 217 ev->flags = flags; 218 ev->cb = cb; 219 ev->cbarg = cbarg; 220 } 221 222 int 223 __event_add(struct event *ev, const struct timeval *timeout) 224 { 225 assert((ev->flags & (EV_PENDING|EV_CURRENT)) == 0); 226 227 if (timeout != NULL) { 228 gettimeofday(&ev->expire, NULL); 229 tv_add(&ev->expire, timeout); 230 ev->timeout = *timeout; 231 ev->flags |= EV_HAS_TIMEOUT; 232 } else 233 ev->flags &= ~EV_HAS_TIMEOUT; 234 235 __event_link(ev); 236 237 return (0); 238 } 239 240 int 241 __event_del(struct event *ev) 242 { 243 assert((ev->flags & EV_CURRENT) == 0); 244 245 if ((ev->flags & EV_PENDING) != 0) { 246 TAILQ_REMOVE(&pending, ev, next); 247 ev->flags &= ~EV_PENDING; 248 } 249 250 return (0); 251 } 252 253 static void 254 __event_add_current(struct event *ev) 255 { 256 assert((ev->flags & (EV_PENDING|EV_CURRENT)) == 0); 257 258 TAILQ_INSERT_TAIL(¤t, ev, next); 259 ev->flags |= EV_CURRENT; 260 } 261 262 static void 263 __event_del_current(struct event *ev) 264 { 265 assert((ev->flags & (EV_CURRENT|EV_PENDING)) == EV_CURRENT); 266 267 TAILQ_REMOVE(¤t, ev, next); 268 ev->flags &= ~EV_CURRENT; 269 } 270 271 static void 272 tv_add(struct timeval *a, struct timeval const *b) 273 { 274 a->tv_sec += b->tv_sec; 275 a->tv_usec += b->tv_usec; 276 277 if(a->tv_usec >= 1000000) { 278 a->tv_usec -= 1000000; 279 a->tv_sec += 1; 280 } 281 } 282 283 static void 284 tv_sub(struct timeval *a, struct timeval const *b) 285 { 286 if (a->tv_usec < b->tv_usec) { 287 a->tv_usec += 1000000; 288 a->tv_sec -= 1; 289 } 290 291 a->tv_usec -= b->tv_usec; 292 a->tv_sec -= b->tv_sec; 293 } 294 295 static int 296 tv_cmp(struct timeval const *a, struct timeval const *b) 297 { 298 if (a->tv_sec > b->tv_sec) 299 return (1); 300 301 if (a->tv_sec < b->tv_sec) 302 return (-1); 303 304 if (a->tv_usec > b->tv_usec) 305 return (1); 306 307 if (a->tv_usec < b->tv_usec) 308 return (-1); 309 310 return (0); 311 } 312 313