1 /* 2 * event.h 3 */ 4 5 /*- 6 * Copyright (c) 2009 Maksim Yevmenkin <m_evmenkin@yahoo.com> 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 /* $FreeBSD$ */ 32 33 /* 34 * Hack to provide libevent (see devel/libevent port) like API. 35 * Should be removed if FreeBSD ever decides to import libevent into base. 36 */ 37 38 #include <sys/select.h> 39 #include <sys/time.h> 40 #include <sys/queue.h> 41 #include <assert.h> 42 #include <stdarg.h> 43 #include <stdio.h> 44 #include <string.h> 45 #include <syslog.h> 46 47 #include "event.h" 48 #include "btpand.h" 49 50 #define __event_link(ev) \ 51 do { \ 52 TAILQ_INSERT_TAIL(&pending, ev, next); \ 53 ev->flags |= EV_PENDING; \ 54 } while (0) 55 56 static void tv_add(struct timeval *, struct timeval const *); 57 static void tv_sub(struct timeval *, struct timeval const *); 58 static int tv_cmp(struct timeval const *, struct timeval const *); 59 static int __event_dispatch(void); 60 static void __event_add_current(struct event *); 61 static void __event_del_current(struct event *); 62 63 64 static TAILQ_HEAD(, event) pending; 65 static TAILQ_HEAD(, event) current; 66 67 void 68 event_init(void) 69 { 70 TAILQ_INIT(&pending); 71 } 72 73 int 74 event_dispatch(void) 75 { 76 while (__event_dispatch() == 0) 77 ; 78 79 return (-1); 80 } 81 82 static int 83 __event_dispatch(void) 84 { 85 fd_set r, w; 86 int nfd; 87 struct event *ev; 88 struct timeval now, timeout, t; 89 90 FD_ZERO(&r); 91 FD_ZERO(&w); 92 93 nfd = 0; 94 95 gettimeofday(&now, NULL); 96 97 timeout.tv_sec = 10; /* arbitrary */ 98 timeout.tv_usec = 0; 99 100 TAILQ_INIT(¤t); 101 102 /* 103 * Build fd_set's 104 */ 105 106 event_log_debug("%s: building fd set...", __func__); 107 108 while (!TAILQ_EMPTY(&pending)) { 109 ev = TAILQ_FIRST(&pending); 110 event_del(ev); 111 112 if (ev->flags & EV_HAS_TIMEOUT) { 113 if (tv_cmp(&now, &ev->expire) >= 0) 114 t.tv_sec = t.tv_usec = 0; 115 else { 116 t = ev->expire; 117 tv_sub(&t, &now); 118 } 119 120 if (tv_cmp(&t, &timeout) < 0) 121 timeout = t; 122 } 123 124 if (ev->fd >= 0) { 125 if (ev->flags & EV_READ) { 126 FD_SET(ev->fd, &r); 127 nfd = (nfd > ev->fd) ? nfd : ev->fd; 128 } 129 130 if (ev->flags & EV_WRITE) { 131 FD_SET(ev->fd, &w); 132 nfd = (nfd > ev->fd) ? nfd : ev->fd; 133 } 134 } 135 136 __event_add_current(ev); 137 } 138 139 event_log_debug("%s: waiting for events...", __func__); 140 141 nfd = select(nfd + 1, &r, &w, NULL, &timeout); 142 if (nfd < 0) 143 return (-1); 144 145 /* 146 * Process current pending 147 */ 148 149 event_log_debug("%s: processing events...", __func__); 150 151 gettimeofday(&now, NULL); 152 153 while (!TAILQ_EMPTY(¤t)) { 154 ev = TAILQ_FIRST(¤t); 155 __event_del_current(ev); 156 157 /* check if fd is ready for reading/writing */ 158 if (nfd > 0 && ev->fd >= 0) { 159 if (FD_ISSET(ev->fd, &r) || FD_ISSET(ev->fd, &w)) { 160 if (ev->flags & EV_PERSIST) { 161 if (ev->flags & EV_HAS_TIMEOUT) 162 event_add(ev, &ev->timeout); 163 else 164 event_add(ev, NULL); 165 } 166 167 nfd --; 168 169 event_log_debug("%s: calling %p(%d, %p), " \ 170 "ev=%p", __func__, ev->cb, ev->fd, 171 ev->cbarg, ev); 172 173 (ev->cb)(ev->fd, 174 (ev->flags & (EV_READ|EV_WRITE)), 175 ev->cbarg); 176 177 continue; 178 } 179 } 180 181 /* if event has no timeout - just requeue */ 182 if ((ev->flags & EV_HAS_TIMEOUT) == 0) { 183 event_add(ev, NULL); 184 continue; 185 } 186 187 /* check if event has expired */ 188 if (tv_cmp(&now, &ev->expire) >= 0) { 189 if (ev->flags & EV_PERSIST) 190 event_add(ev, &ev->timeout); 191 192 event_log_debug("%s: calling %p(%d, %p), ev=%p", 193 __func__, ev->cb, ev->fd, ev->cbarg, ev); 194 195 (ev->cb)(ev->fd, 196 (ev->flags & (EV_READ|EV_WRITE)), 197 ev->cbarg); 198 199 continue; 200 } 201 202 assert((ev->flags & (EV_PENDING|EV_CURRENT)) == 0); 203 __event_link(ev); 204 } 205 206 return (0); 207 } 208 209 void 210 __event_set(struct event *ev, int fd, short flags, 211 void (*cb)(int, short, void *), void *cbarg) 212 { 213 ev->fd = fd; 214 ev->flags = flags; 215 ev->cb = cb; 216 ev->cbarg = cbarg; 217 } 218 219 int 220 __event_add(struct event *ev, const struct timeval *timeout) 221 { 222 assert((ev->flags & (EV_PENDING|EV_CURRENT)) == 0); 223 224 if (timeout != NULL) { 225 gettimeofday(&ev->expire, NULL); 226 tv_add(&ev->expire, timeout); 227 ev->timeout = *timeout; 228 ev->flags |= EV_HAS_TIMEOUT; 229 } else 230 ev->flags &= ~EV_HAS_TIMEOUT; 231 232 __event_link(ev); 233 234 return (0); 235 } 236 237 int 238 __event_del(struct event *ev) 239 { 240 assert((ev->flags & EV_CURRENT) == 0); 241 242 if ((ev->flags & EV_PENDING) != 0) { 243 TAILQ_REMOVE(&pending, ev, next); 244 ev->flags &= ~EV_PENDING; 245 } 246 247 return (0); 248 } 249 250 static void 251 __event_add_current(struct event *ev) 252 { 253 assert((ev->flags & (EV_PENDING|EV_CURRENT)) == 0); 254 255 TAILQ_INSERT_TAIL(¤t, ev, next); 256 ev->flags |= EV_CURRENT; 257 } 258 259 static void 260 __event_del_current(struct event *ev) 261 { 262 assert((ev->flags & (EV_CURRENT|EV_PENDING)) == EV_CURRENT); 263 264 TAILQ_REMOVE(¤t, ev, next); 265 ev->flags &= ~EV_CURRENT; 266 } 267 268 static void 269 tv_add(struct timeval *a, struct timeval const *b) 270 { 271 a->tv_sec += b->tv_sec; 272 a->tv_usec += b->tv_usec; 273 274 if(a->tv_usec >= 1000000) { 275 a->tv_usec -= 1000000; 276 a->tv_sec += 1; 277 } 278 } 279 280 static void 281 tv_sub(struct timeval *a, struct timeval const *b) 282 { 283 if (a->tv_usec < b->tv_usec) { 284 a->tv_usec += 1000000; 285 a->tv_sec -= 1; 286 } 287 288 a->tv_usec -= b->tv_usec; 289 a->tv_sec -= b->tv_sec; 290 } 291 292 static int 293 tv_cmp(struct timeval const *a, struct timeval const *b) 294 { 295 if (a->tv_sec > b->tv_sec) 296 return (1); 297 298 if (a->tv_sec < b->tv_sec) 299 return (-1); 300 301 if (a->tv_usec > b->tv_usec) 302 return (1); 303 304 if (a->tv_usec < b->tv_usec) 305 return (-1); 306 307 return (0); 308 } 309 310