| OLD | NEW |
|---|
| (Empty) |
| 1 /* | |
| 2 * Copyright 2000-2004 Niels Provos <provos@citi.umich.edu> | |
| 3 * All rights reserved. | |
| 4 * | |
| 5 * Redistribution and use in source and binary forms, with or without | |
| 6 * modification, are permitted provided that the following conditions | |
| 7 * are met: | |
| 8 * 1. Redistributions of source code must retain the above copyright | |
| 9 * notice, this list of conditions and the following disclaimer. | |
| 10 * 2. Redistributions in binary form must reproduce the above copyright | |
| 11 * notice, this list of conditions and the following disclaimer in the | |
| 12 * documentation and/or other materials provided with the distribution. | |
| 13 * 3. The name of the author may not be used to endorse or promote products | |
| 14 * derived from this software without specific prior written permission. | |
| 15 * | |
| 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
| 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
| 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
| 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
| 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
| 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
| 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 26 */ | |
| 27 #ifdef HAVE_CONFIG_H | |
| 28 #include "config.h" | |
| 29 #endif | |
| 30 | |
| 31 #include <sys/types.h> | |
| 32 #include <sys/resource.h> | |
| 33 #ifdef HAVE_SYS_TIME_H | |
| 34 #include <sys/time.h> | |
| 35 #else | |
| 36 #include <sys/_libevent_time.h> | |
| 37 #endif | |
| 38 #include <sys/queue.h> | |
| 39 #include <sys/devpoll.h> | |
| 40 #include <signal.h> | |
| 41 #include <stdio.h> | |
| 42 #include <stdlib.h> | |
| 43 #include <string.h> | |
| 44 #include <unistd.h> | |
| 45 #include <fcntl.h> | |
| 46 #include <errno.h> | |
| 47 #include <assert.h> | |
| 48 | |
| 49 #include "event.h" | |
| 50 #include "event-internal.h" | |
| 51 #include "evsignal.h" | |
| 52 #include "log.h" | |
| 53 | |
| 54 /* due to limitations in the devpoll interface, we need to keep track of | |
| 55 * all file descriptors outself. | |
| 56 */ | |
| 57 struct evdevpoll { | |
| 58 struct event *evread; | |
| 59 struct event *evwrite; | |
| 60 }; | |
| 61 | |
| 62 struct devpollop { | |
| 63 struct evdevpoll *fds; | |
| 64 int nfds; | |
| 65 struct pollfd *events; | |
| 66 int nevents; | |
| 67 int dpfd; | |
| 68 struct pollfd *changes; | |
| 69 int nchanges; | |
| 70 }; | |
| 71 | |
| 72 static void *devpoll_init (struct event_base *); | |
| 73 static int devpoll_add (void *, struct event *); | |
| 74 static int devpoll_del (void *, struct event *); | |
| 75 static int devpoll_dispatch (struct event_base *, void *, struct timeval *); | |
| 76 static void devpoll_dealloc (struct event_base *, void *); | |
| 77 | |
| 78 const struct eventop devpollops = { | |
| 79 "devpoll", | |
| 80 devpoll_init, | |
| 81 devpoll_add, | |
| 82 devpoll_del, | |
| 83 devpoll_dispatch, | |
| 84 devpoll_dealloc, | |
| 85 1 /* need reinit */ | |
| 86 }; | |
| 87 | |
| 88 #define NEVENT 32000 | |
| 89 | |
| 90 static int | |
| 91 devpoll_commit(struct devpollop *devpollop) | |
| 92 { | |
| 93 /* | |
| 94 * Due to a bug in Solaris, we have to use pwrite with an offset of 0. | |
| 95 * Write is limited to 2GB of data, until it will fail. | |
| 96 */ | |
| 97 if (pwrite(devpollop->dpfd, devpollop->changes, | |
| 98 sizeof(struct pollfd) * devpollop->nchanges, 0) == -1) | |
| 99 return(-1); | |
| 100 | |
| 101 devpollop->nchanges = 0; | |
| 102 return(0); | |
| 103 } | |
| 104 | |
| 105 static int | |
| 106 devpoll_queue(struct devpollop *devpollop, int fd, int events) { | |
| 107 struct pollfd *pfd; | |
| 108 | |
| 109 if (devpollop->nchanges >= devpollop->nevents) { | |
| 110 /* | |
| 111 * Change buffer is full, must commit it to /dev/poll before | |
| 112 * adding more | |
| 113 */ | |
| 114 if (devpoll_commit(devpollop) != 0) | |
| 115 return(-1); | |
| 116 } | |
| 117 | |
| 118 pfd = &devpollop->changes[devpollop->nchanges++]; | |
| 119 pfd->fd = fd; | |
| 120 pfd->events = events; | |
| 121 pfd->revents = 0; | |
| 122 | |
| 123 return(0); | |
| 124 } | |
| 125 | |
| 126 static void * | |
| 127 devpoll_init(struct event_base *base) | |
| 128 { | |
| 129 int dpfd, nfiles = NEVENT; | |
| 130 struct rlimit rl; | |
| 131 struct devpollop *devpollop; | |
| 132 | |
| 133 /* Disable devpoll when this environment variable is set */ | |
| 134 if (evutil_getenv("EVENT_NODEVPOLL")) | |
| 135 return (NULL); | |
| 136 | |
| 137 if (!(devpollop = calloc(1, sizeof(struct devpollop)))) | |
| 138 return (NULL); | |
| 139 | |
| 140 if (getrlimit(RLIMIT_NOFILE, &rl) == 0 && | |
| 141 rl.rlim_cur != RLIM_INFINITY) | |
| 142 nfiles = rl.rlim_cur; | |
| 143 | |
| 144 /* Initialize the kernel queue */ | |
| 145 if ((dpfd = open("/dev/poll", O_RDWR)) == -1) { | |
| 146 event_warn("open: /dev/poll"); | |
| 147 free(devpollop); | |
| 148 return (NULL); | |
| 149 } | |
| 150 | |
| 151 devpollop->dpfd = dpfd; | |
| 152 | |
| 153 /* Initialize fields */ | |
| 154 devpollop->events = calloc(nfiles, sizeof(struct pollfd)); | |
| 155 if (devpollop->events == NULL) { | |
| 156 free(devpollop); | |
| 157 close(dpfd); | |
| 158 return (NULL); | |
| 159 } | |
| 160 devpollop->nevents = nfiles; | |
| 161 | |
| 162 devpollop->fds = calloc(nfiles, sizeof(struct evdevpoll)); | |
| 163 if (devpollop->fds == NULL) { | |
| 164 free(devpollop->events); | |
| 165 free(devpollop); | |
| 166 close(dpfd); | |
| 167 return (NULL); | |
| 168 } | |
| 169 devpollop->nfds = nfiles; | |
| 170 | |
| 171 devpollop->changes = calloc(nfiles, sizeof(struct pollfd)); | |
| 172 if (devpollop->changes == NULL) { | |
| 173 free(devpollop->fds); | |
| 174 free(devpollop->events); | |
| 175 free(devpollop); | |
| 176 close(dpfd); | |
| 177 return (NULL); | |
| 178 } | |
| 179 | |
| 180 evsignal_init(base); | |
| 181 | |
| 182 return (devpollop); | |
| 183 } | |
| 184 | |
| 185 static int | |
| 186 devpoll_recalc(struct event_base *base, void *arg, int max) | |
| 187 { | |
| 188 struct devpollop *devpollop = arg; | |
| 189 | |
| 190 if (max >= devpollop->nfds) { | |
| 191 struct evdevpoll *fds; | |
| 192 int nfds; | |
| 193 | |
| 194 nfds = devpollop->nfds; | |
| 195 while (nfds <= max) | |
| 196 nfds <<= 1; | |
| 197 | |
| 198 fds = realloc(devpollop->fds, nfds * sizeof(struct evdevpoll)); | |
| 199 if (fds == NULL) { | |
| 200 event_warn("realloc"); | |
| 201 return (-1); | |
| 202 } | |
| 203 devpollop->fds = fds; | |
| 204 memset(fds + devpollop->nfds, 0, | |
| 205 (nfds - devpollop->nfds) * sizeof(struct evdevpoll)); | |
| 206 devpollop->nfds = nfds; | |
| 207 } | |
| 208 | |
| 209 return (0); | |
| 210 } | |
| 211 | |
| 212 static int | |
| 213 devpoll_dispatch(struct event_base *base, void *arg, struct timeval *tv) | |
| 214 { | |
| 215 struct devpollop *devpollop = arg; | |
| 216 struct pollfd *events = devpollop->events; | |
| 217 struct dvpoll dvp; | |
| 218 struct evdevpoll *evdp; | |
| 219 int i, res, timeout = -1; | |
| 220 | |
| 221 if (devpollop->nchanges) | |
| 222 devpoll_commit(devpollop); | |
| 223 | |
| 224 if (tv != NULL) | |
| 225 timeout = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000; | |
| 226 | |
| 227 dvp.dp_fds = devpollop->events; | |
| 228 dvp.dp_nfds = devpollop->nevents; | |
| 229 dvp.dp_timeout = timeout; | |
| 230 | |
| 231 res = ioctl(devpollop->dpfd, DP_POLL, &dvp); | |
| 232 | |
| 233 if (res == -1) { | |
| 234 if (errno != EINTR) { | |
| 235 event_warn("ioctl: DP_POLL"); | |
| 236 return (-1); | |
| 237 } | |
| 238 | |
| 239 evsignal_process(base); | |
| 240 return (0); | |
| 241 } else if (base->sig.evsignal_caught) { | |
| 242 evsignal_process(base); | |
| 243 } | |
| 244 | |
| 245 event_debug(("%s: devpoll_wait reports %d", __func__, res)); | |
| 246 | |
| 247 for (i = 0; i < res; i++) { | |
| 248 int which = 0; | |
| 249 int what = events[i].revents; | |
| 250 struct event *evread = NULL, *evwrite = NULL; | |
| 251 | |
| 252 assert(events[i].fd < devpollop->nfds); | |
| 253 evdp = &devpollop->fds[events[i].fd]; | |
| 254 | |
| 255 if (what & POLLHUP) | |
| 256 what |= POLLIN | POLLOUT; | |
| 257 else if (what & POLLERR) | |
| 258 what |= POLLIN | POLLOUT; | |
| 259 | |
| 260 if (what & POLLIN) { | |
| 261 evread = evdp->evread; | |
| 262 which |= EV_READ; | |
| 263 } | |
| 264 | |
| 265 if (what & POLLOUT) { | |
| 266 evwrite = evdp->evwrite; | |
| 267 which |= EV_WRITE; | |
| 268 } | |
| 269 | |
| 270 if (!which) | |
| 271 continue; | |
| 272 | |
| 273 if (evread != NULL && !(evread->ev_events & EV_PERSIST)) | |
| 274 event_del(evread); | |
| 275 if (evwrite != NULL && evwrite != evread && | |
| 276 !(evwrite->ev_events & EV_PERSIST)) | |
| 277 event_del(evwrite); | |
| 278 | |
| 279 if (evread != NULL) | |
| 280 event_active(evread, EV_READ, 1); | |
| 281 if (evwrite != NULL) | |
| 282 event_active(evwrite, EV_WRITE, 1); | |
| 283 } | |
| 284 | |
| 285 return (0); | |
| 286 } | |
| 287 | |
| 288 | |
| 289 static int | |
| 290 devpoll_add(void *arg, struct event *ev) | |
| 291 { | |
| 292 struct devpollop *devpollop = arg; | |
| 293 struct evdevpoll *evdp; | |
| 294 int fd, events; | |
| 295 | |
| 296 if (ev->ev_events & EV_SIGNAL) | |
| 297 return (evsignal_add(ev)); | |
| 298 | |
| 299 fd = ev->ev_fd; | |
| 300 if (fd >= devpollop->nfds) { | |
| 301 /* Extend the file descriptor array as necessary */ | |
| 302 if (devpoll_recalc(ev->ev_base, devpollop, fd) == -1) | |
| 303 return (-1); | |
| 304 } | |
| 305 evdp = &devpollop->fds[fd]; | |
| 306 | |
| 307 /* | |
| 308 * It's not necessary to OR the existing read/write events that we | |
| 309 * are currently interested in with the new event we are adding. | |
| 310 * The /dev/poll driver ORs any new events with the existing events | |
| 311 * that it has cached for the fd. | |
| 312 */ | |
| 313 | |
| 314 events = 0; | |
| 315 if (ev->ev_events & EV_READ) { | |
| 316 if (evdp->evread && evdp->evread != ev) { | |
| 317 /* There is already a different read event registered */ | |
| 318 return(-1); | |
| 319 } | |
| 320 events |= POLLIN; | |
| 321 } | |
| 322 | |
| 323 if (ev->ev_events & EV_WRITE) { | |
| 324 if (evdp->evwrite && evdp->evwrite != ev) { | |
| 325 /* There is already a different write event registered */ | |
| 326 return(-1); | |
| 327 } | |
| 328 events |= POLLOUT; | |
| 329 } | |
| 330 | |
| 331 if (devpoll_queue(devpollop, fd, events) != 0) | |
| 332 return(-1); | |
| 333 | |
| 334 /* Update events responsible */ | |
| 335 if (ev->ev_events & EV_READ) | |
| 336 evdp->evread = ev; | |
| 337 if (ev->ev_events & EV_WRITE) | |
| 338 evdp->evwrite = ev; | |
| 339 | |
| 340 return (0); | |
| 341 } | |
| 342 | |
| 343 static int | |
| 344 devpoll_del(void *arg, struct event *ev) | |
| 345 { | |
| 346 struct devpollop *devpollop = arg; | |
| 347 struct evdevpoll *evdp; | |
| 348 int fd, events; | |
| 349 int needwritedelete = 1, needreaddelete = 1; | |
| 350 | |
| 351 if (ev->ev_events & EV_SIGNAL) | |
| 352 return (evsignal_del(ev)); | |
| 353 | |
| 354 fd = ev->ev_fd; | |
| 355 if (fd >= devpollop->nfds) | |
| 356 return (0); | |
| 357 evdp = &devpollop->fds[fd]; | |
| 358 | |
| 359 events = 0; | |
| 360 if (ev->ev_events & EV_READ) | |
| 361 events |= POLLIN; | |
| 362 if (ev->ev_events & EV_WRITE) | |
| 363 events |= POLLOUT; | |
| 364 | |
| 365 /* | |
| 366 * The only way to remove an fd from the /dev/poll monitored set is | |
| 367 * to use POLLREMOVE by itself. This removes ALL events for the fd | |
| 368 * provided so if we care about two events and are only removing one | |
| 369 * we must re-add the other event after POLLREMOVE. | |
| 370 */ | |
| 371 | |
| 372 if (devpoll_queue(devpollop, fd, POLLREMOVE) != 0) | |
| 373 return(-1); | |
| 374 | |
| 375 if ((events & (POLLIN|POLLOUT)) != (POLLIN|POLLOUT)) { | |
| 376 /* | |
| 377 * We're not deleting all events, so we must resubmit the | |
| 378 * event that we are still interested in if one exists. | |
| 379 */ | |
| 380 | |
| 381 if ((events & POLLIN) && evdp->evwrite != NULL) { | |
| 382 /* Deleting read, still care about write */ | |
| 383 devpoll_queue(devpollop, fd, POLLOUT); | |
| 384 needwritedelete = 0; | |
| 385 } else if ((events & POLLOUT) && evdp->evread != NULL) { | |
| 386 /* Deleting write, still care about read */ | |
| 387 devpoll_queue(devpollop, fd, POLLIN); | |
| 388 needreaddelete = 0; | |
| 389 } | |
| 390 } | |
| 391 | |
| 392 if (needreaddelete) | |
| 393 evdp->evread = NULL; | |
| 394 if (needwritedelete) | |
| 395 evdp->evwrite = NULL; | |
| 396 | |
| 397 return (0); | |
| 398 } | |
| 399 | |
| 400 static void | |
| 401 devpoll_dealloc(struct event_base *base, void *arg) | |
| 402 { | |
| 403 struct devpollop *devpollop = arg; | |
| 404 | |
| 405 evsignal_dealloc(base); | |
| 406 if (devpollop->fds) | |
| 407 free(devpollop->fds); | |
| 408 if (devpollop->events) | |
| 409 free(devpollop->events); | |
| 410 if (devpollop->changes) | |
| 411 free(devpollop->changes); | |
| 412 if (devpollop->dpfd >= 0) | |
| 413 close(devpollop->dpfd); | |
| 414 | |
| 415 memset(devpollop, 0, sizeof(struct devpollop)); | |
| 416 free(devpollop); | |
| 417 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1531573008:
move libevent into base (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master