The Tor Browser / file comparison
comparison: ipc/chromium/src/third_party/libevent/kqueue.c
ipc/chromium/src/third_party/libevent/kqueue.c
- branch
- TOR_BUG_9701
- changeset 11
- deefc01c0e14
equal
deleted
inserted
replaced
| -1:000000000000 | 0:14d38a2fdf73 |
|---|---|
| 1 /* $OpenBSD: kqueue.c,v 1.5 2002/07/10 14:41:31 art Exp $ */ | |
| 2 | |
| 3 /* | |
| 4 * Copyright 2000-2007 Niels Provos <provos@citi.umich.edu> | |
| 5 * Copyright 2007-2012 Niels Provos and Nick Mathewson | |
| 6 * | |
| 7 * Redistribution and use in source and binary forms, with or without | |
| 8 * modification, are permitted provided that the following conditions | |
| 9 * are met: | |
| 10 * 1. Redistributions of source code must retain the above copyright | |
| 11 * notice, this list of conditions and the following disclaimer. | |
| 12 * 2. Redistributions in binary form must reproduce the above copyright | |
| 13 * notice, this list of conditions and the following disclaimer in the | |
| 14 * documentation and/or other materials provided with the distribution. | |
| 15 * 3. The name of the author may not be used to endorse or promote products | |
| 16 * derived from this software without specific prior written permission. | |
| 17 * | |
| 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
| 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
| 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
| 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
| 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
| 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
| 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 28 */ | |
| 29 #include "event2/event-config.h" | |
| 30 | |
| 31 #define _GNU_SOURCE | |
| 32 | |
| 33 #include <sys/types.h> | |
| 34 #ifdef _EVENT_HAVE_SYS_TIME_H | |
| 35 #include <sys/time.h> | |
| 36 #endif | |
| 37 #include <sys/queue.h> | |
| 38 #include <sys/event.h> | |
| 39 #include <signal.h> | |
| 40 #include <stdio.h> | |
| 41 #include <stdlib.h> | |
| 42 #include <string.h> | |
| 43 #include <unistd.h> | |
| 44 #include <errno.h> | |
| 45 #ifdef _EVENT_HAVE_INTTYPES_H | |
| 46 #include <inttypes.h> | |
| 47 #endif | |
| 48 | |
| 49 /* Some platforms apparently define the udata field of struct kevent as | |
| 50 * intptr_t, whereas others define it as void*. There doesn't seem to be an | |
| 51 * easy way to tell them apart via autoconf, so we need to use OS macros. */ | |
| 52 #if defined(_EVENT_HAVE_INTTYPES_H) && !defined(__OpenBSD__) && !defined(__FreeBSD__) && !defined(__darwin__) && !defined(__APPLE__) | |
| 53 #define PTR_TO_UDATA(x) ((intptr_t)(x)) | |
| 54 #define INT_TO_UDATA(x) ((intptr_t)(x)) | |
| 55 #else | |
| 56 #define PTR_TO_UDATA(x) (x) | |
| 57 #define INT_TO_UDATA(x) ((void*)(x)) | |
| 58 #endif | |
| 59 | |
| 60 #include "event-internal.h" | |
| 61 #include "log-internal.h" | |
| 62 #include "evmap-internal.h" | |
| 63 #include "event2/thread.h" | |
| 64 #include "evthread-internal.h" | |
| 65 #include "changelist-internal.h" | |
| 66 | |
| 67 #define NEVENT 64 | |
| 68 | |
| 69 struct kqop { | |
| 70 struct kevent *changes; | |
| 71 int changes_size; | |
| 72 | |
| 73 struct kevent *events; | |
| 74 int events_size; | |
| 75 int kq; | |
| 76 pid_t pid; | |
| 77 }; | |
| 78 | |
| 79 static void kqop_free(struct kqop *kqop); | |
| 80 | |
| 81 static void *kq_init(struct event_base *); | |
| 82 static int kq_sig_add(struct event_base *, int, short, short, void *); | |
| 83 static int kq_sig_del(struct event_base *, int, short, short, void *); | |
| 84 static int kq_dispatch(struct event_base *, struct timeval *); | |
| 85 static void kq_dealloc(struct event_base *); | |
| 86 | |
| 87 const struct eventop kqops = { | |
| 88 "kqueue", | |
| 89 kq_init, | |
| 90 event_changelist_add, | |
| 91 event_changelist_del, | |
| 92 kq_dispatch, | |
| 93 kq_dealloc, | |
| 94 1 /* need reinit */, | |
| 95 EV_FEATURE_ET|EV_FEATURE_O1|EV_FEATURE_FDS, | |
| 96 EVENT_CHANGELIST_FDINFO_SIZE | |
| 97 }; | |
| 98 | |
| 99 static const struct eventop kqsigops = { | |
| 100 "kqueue_signal", | |
| 101 NULL, | |
| 102 kq_sig_add, | |
| 103 kq_sig_del, | |
| 104 NULL, | |
| 105 NULL, | |
| 106 1 /* need reinit */, | |
| 107 0, | |
| 108 0 | |
| 109 }; | |
| 110 | |
| 111 static void * | |
| 112 kq_init(struct event_base *base) | |
| 113 { | |
| 114 int kq = -1; | |
| 115 struct kqop *kqueueop = NULL; | |
| 116 | |
| 117 if (!(kqueueop = mm_calloc(1, sizeof(struct kqop)))) | |
| 118 return (NULL); | |
| 119 | |
| 120 /* Initialize the kernel queue */ | |
| 121 | |
| 122 if ((kq = kqueue()) == -1) { | |
| 123 event_warn("kqueue"); | |
| 124 goto err; | |
| 125 } | |
| 126 | |
| 127 kqueueop->kq = kq; | |
| 128 | |
| 129 kqueueop->pid = getpid(); | |
| 130 | |
| 131 /* Initialize fields */ | |
| 132 kqueueop->changes = mm_calloc(NEVENT, sizeof(struct kevent)); | |
| 133 if (kqueueop->changes == NULL) | |
| 134 goto err; | |
| 135 kqueueop->events = mm_calloc(NEVENT, sizeof(struct kevent)); | |
| 136 if (kqueueop->events == NULL) | |
| 137 goto err; | |
| 138 kqueueop->events_size = kqueueop->changes_size = NEVENT; | |
| 139 | |
| 140 /* Check for Mac OS X kqueue bug. */ | |
| 141 memset(&kqueueop->changes[0], 0, sizeof kqueueop->changes[0]); | |
| 142 kqueueop->changes[0].ident = -1; | |
| 143 kqueueop->changes[0].filter = EVFILT_READ; | |
| 144 kqueueop->changes[0].flags = EV_ADD; | |
| 145 /* | |
| 146 * If kqueue works, then kevent will succeed, and it will | |
| 147 * stick an error in events[0]. If kqueue is broken, then | |
| 148 * kevent will fail. | |
| 149 */ | |
| 150 if (kevent(kq, | |
| 151 kqueueop->changes, 1, kqueueop->events, NEVENT, NULL) != 1 || | |
| 152 (int)kqueueop->events[0].ident != -1 || | |
| 153 kqueueop->events[0].flags != EV_ERROR) { | |
| 154 event_warn("%s: detected broken kqueue; not using.", __func__); | |
| 155 goto err; | |
| 156 } | |
| 157 | |
| 158 base->evsigsel = &kqsigops; | |
| 159 | |
| 160 return (kqueueop); | |
| 161 err: | |
| 162 if (kqueueop) | |
| 163 kqop_free(kqueueop); | |
| 164 | |
| 165 return (NULL); | |
| 166 } | |
| 167 | |
| 168 #define ADD_UDATA 0x30303 | |
| 169 | |
| 170 static void | |
| 171 kq_setup_kevent(struct kevent *out, evutil_socket_t fd, int filter, short change) | |
| 172 { | |
| 173 memset(out, 0, sizeof(struct kevent)); | |
| 174 out->ident = fd; | |
| 175 out->filter = filter; | |
| 176 | |
| 177 if (change & EV_CHANGE_ADD) { | |
| 178 out->flags = EV_ADD; | |
| 179 /* We set a magic number here so that we can tell 'add' | |
| 180 * errors from 'del' errors. */ | |
| 181 out->udata = INT_TO_UDATA(ADD_UDATA); | |
| 182 if (change & EV_ET) | |
| 183 out->flags |= EV_CLEAR; | |
| 184 #ifdef NOTE_EOF | |
| 185 /* Make it behave like select() and poll() */ | |
| 186 if (filter == EVFILT_READ) | |
| 187 out->fflags = NOTE_EOF; | |
| 188 #endif | |
| 189 } else { | |
| 190 EVUTIL_ASSERT(change & EV_CHANGE_DEL); | |
| 191 out->flags = EV_DELETE; | |
| 192 } | |
| 193 } | |
| 194 | |
| 195 static int | |
| 196 kq_build_changes_list(const struct event_changelist *changelist, | |
| 197 struct kqop *kqop) | |
| 198 { | |
| 199 int i; | |
| 200 int n_changes = 0; | |
| 201 | |
| 202 for (i = 0; i < changelist->n_changes; ++i) { | |
| 203 struct event_change *in_ch = &changelist->changes[i]; | |
| 204 struct kevent *out_ch; | |
| 205 if (n_changes >= kqop->changes_size - 1) { | |
| 206 int newsize = kqop->changes_size * 2; | |
| 207 struct kevent *newchanges; | |
| 208 | |
| 209 newchanges = mm_realloc(kqop->changes, | |
| 210 newsize * sizeof(struct kevent)); | |
| 211 if (newchanges == NULL) { | |
| 212 event_warn("%s: realloc", __func__); | |
| 213 return (-1); | |
| 214 } | |
| 215 kqop->changes = newchanges; | |
| 216 kqop->changes_size = newsize; | |
| 217 } | |
| 218 if (in_ch->read_change) { | |
| 219 out_ch = &kqop->changes[n_changes++]; | |
| 220 kq_setup_kevent(out_ch, in_ch->fd, EVFILT_READ, | |
| 221 in_ch->read_change); | |
| 222 } | |
| 223 if (in_ch->write_change) { | |
| 224 out_ch = &kqop->changes[n_changes++]; | |
| 225 kq_setup_kevent(out_ch, in_ch->fd, EVFILT_WRITE, | |
| 226 in_ch->write_change); | |
| 227 } | |
| 228 } | |
| 229 return n_changes; | |
| 230 } | |
| 231 | |
| 232 static int | |
| 233 kq_grow_events(struct kqop *kqop, size_t new_size) | |
| 234 { | |
| 235 struct kevent *newresult; | |
| 236 | |
| 237 newresult = mm_realloc(kqop->events, | |
| 238 new_size * sizeof(struct kevent)); | |
| 239 | |
| 240 if (newresult) { | |
| 241 kqop->events = newresult; | |
| 242 kqop->events_size = new_size; | |
| 243 return 0; | |
| 244 } else { | |
| 245 return -1; | |
| 246 } | |
| 247 } | |
| 248 | |
| 249 static int | |
| 250 kq_dispatch(struct event_base *base, struct timeval *tv) | |
| 251 { | |
| 252 struct kqop *kqop = base->evbase; | |
| 253 struct kevent *events = kqop->events; | |
| 254 struct kevent *changes; | |
| 255 struct timespec ts, *ts_p = NULL; | |
| 256 int i, n_changes, res; | |
| 257 | |
| 258 if (tv != NULL) { | |
| 259 TIMEVAL_TO_TIMESPEC(tv, &ts); | |
| 260 ts_p = &ts; | |
| 261 } | |
| 262 | |
| 263 /* Build "changes" from "base->changes" */ | |
| 264 EVUTIL_ASSERT(kqop->changes); | |
| 265 n_changes = kq_build_changes_list(&base->changelist, kqop); | |
| 266 if (n_changes < 0) | |
| 267 return -1; | |
| 268 | |
| 269 event_changelist_remove_all(&base->changelist, base); | |
| 270 | |
| 271 /* steal the changes array in case some broken code tries to call | |
| 272 * dispatch twice at once. */ | |
| 273 changes = kqop->changes; | |
| 274 kqop->changes = NULL; | |
| 275 | |
| 276 /* Make sure that 'events' is at least as long as the list of changes: | |
| 277 * otherwise errors in the changes can get reported as a -1 return | |
| 278 * value from kevent() rather than as EV_ERROR events in the events | |
| 279 * array. | |
| 280 * | |
| 281 * (We could instead handle -1 return values from kevent() by | |
| 282 * retrying with a smaller changes array or a larger events array, | |
| 283 * but this approach seems less risky for now.) | |
| 284 */ | |
| 285 if (kqop->events_size < n_changes) { | |
| 286 int new_size = kqop->events_size; | |
| 287 do { | |
| 288 new_size *= 2; | |
| 289 } while (new_size < n_changes); | |
| 290 | |
| 291 kq_grow_events(kqop, new_size); | |
| 292 events = kqop->events; | |
| 293 } | |
| 294 | |
| 295 EVBASE_RELEASE_LOCK(base, th_base_lock); | |
| 296 | |
| 297 res = kevent(kqop->kq, changes, n_changes, | |
| 298 events, kqop->events_size, ts_p); | |
| 299 | |
| 300 EVBASE_ACQUIRE_LOCK(base, th_base_lock); | |
| 301 | |
| 302 EVUTIL_ASSERT(kqop->changes == NULL); | |
| 303 kqop->changes = changes; | |
| 304 | |
| 305 if (res == -1) { | |
| 306 if (errno != EINTR) { | |
| 307 event_warn("kevent"); | |
| 308 return (-1); | |
| 309 } | |
| 310 | |
| 311 return (0); | |
| 312 } | |
| 313 | |
| 314 event_debug(("%s: kevent reports %d", __func__, res)); | |
| 315 | |
| 316 for (i = 0; i < res; i++) { | |
| 317 int which = 0; | |
| 318 | |
| 319 if (events[i].flags & EV_ERROR) { | |
| 320 switch (events[i].data) { | |
| 321 | |
| 322 /* Can occur on delete if we are not currently | |
| 323 * watching any events on this fd. That can | |
| 324 * happen when the fd was closed and another | |
| 325 * file was opened with that fd. */ | |
| 326 case ENOENT: | |
| 327 /* Can occur for reasons not fully understood | |
| 328 * on FreeBSD. */ | |
| 329 case EINVAL: | |
| 330 continue; | |
| 331 | |
| 332 /* Can occur on a delete if the fd is closed. */ | |
| 333 case EBADF: | |
| 334 /* XXXX On NetBSD, we can also get EBADF if we | |
| 335 * try to add the write side of a pipe, but | |
| 336 * the read side has already been closed. | |
| 337 * Other BSDs call this situation 'EPIPE'. It | |
| 338 * would be good if we had a way to report | |
| 339 * this situation. */ | |
| 340 continue; | |
| 341 /* These two can occur on an add if the fd was one side | |
| 342 * of a pipe, and the other side was closed. */ | |
| 343 case EPERM: | |
| 344 case EPIPE: | |
| 345 /* Report read events, if we're listening for | |
| 346 * them, so that the user can learn about any | |
| 347 * add errors. (If the operation was a | |
| 348 * delete, then udata should be cleared.) */ | |
| 349 if (events[i].udata) { | |
| 350 /* The operation was an add: | |
| 351 * report the error as a read. */ | |
| 352 which |= EV_READ; | |
| 353 break; | |
| 354 } else { | |
| 355 /* The operation was a del: | |
| 356 * report nothing. */ | |
| 357 continue; | |
| 358 } | |
| 359 | |
| 360 /* Other errors shouldn't occur. */ | |
| 361 default: | |
| 362 errno = events[i].data; | |
| 363 return (-1); | |
| 364 } | |
| 365 } else if (events[i].filter == EVFILT_READ) { | |
| 366 which |= EV_READ; | |
| 367 } else if (events[i].filter == EVFILT_WRITE) { | |
| 368 which |= EV_WRITE; | |
| 369 } else if (events[i].filter == EVFILT_SIGNAL) { | |
| 370 which |= EV_SIGNAL; | |
| 371 } | |
| 372 | |
| 373 if (!which) | |
| 374 continue; | |
| 375 | |
| 376 if (events[i].filter == EVFILT_SIGNAL) { | |
| 377 evmap_signal_active(base, events[i].ident, 1); | |
| 378 } else { | |
| 379 evmap_io_active(base, events[i].ident, which | EV_ET); | |
| 380 } | |
| 381 } | |
| 382 | |
| 383 if (res == kqop->events_size) { | |
| 384 /* We used all the events space that we have. Maybe we should | |
| 385 make it bigger. */ | |
| 386 kq_grow_events(kqop, kqop->events_size * 2); | |
| 387 } | |
| 388 | |
| 389 return (0); | |
| 390 } | |
| 391 | |
| 392 static void | |
| 393 kqop_free(struct kqop *kqop) | |
| 394 { | |
| 395 if (kqop->changes) | |
| 396 mm_free(kqop->changes); | |
| 397 if (kqop->events) | |
| 398 mm_free(kqop->events); | |
| 399 if (kqop->kq >= 0 && kqop->pid == getpid()) | |
| 400 close(kqop->kq); | |
| 401 memset(kqop, 0, sizeof(struct kqop)); | |
| 402 mm_free(kqop); | |
| 403 } | |
| 404 | |
| 405 static void | |
| 406 kq_dealloc(struct event_base *base) | |
| 407 { | |
| 408 struct kqop *kqop = base->evbase; | |
| 409 evsig_dealloc(base); | |
| 410 kqop_free(kqop); | |
| 411 } | |
| 412 | |
| 413 /* signal handling */ | |
| 414 static int | |
| 415 kq_sig_add(struct event_base *base, int nsignal, short old, short events, void *p) | |
| 416 { | |
| 417 struct kqop *kqop = base->evbase; | |
| 418 struct kevent kev; | |
| 419 struct timespec timeout = { 0, 0 }; | |
| 420 (void)p; | |
| 421 | |
| 422 EVUTIL_ASSERT(nsignal >= 0 && nsignal < NSIG); | |
| 423 | |
| 424 memset(&kev, 0, sizeof(kev)); | |
| 425 kev.ident = nsignal; | |
| 426 kev.filter = EVFILT_SIGNAL; | |
| 427 kev.flags = EV_ADD; | |
| 428 | |
| 429 /* Be ready for the signal if it is sent any | |
| 430 * time between now and the next call to | |
| 431 * kq_dispatch. */ | |
| 432 if (kevent(kqop->kq, &kev, 1, NULL, 0, &timeout) == -1) | |
| 433 return (-1); | |
| 434 | |
| 435 /* Backported from | |
| 436 * https://github.com/nmathewson/Libevent/commit/148458e0a1fd25e167aa2ef229d1c9a70b27c3e9 */ | |
| 437 /* We can set the handler for most signals to SIG_IGN and | |
| 438 * still have them reported to us in the queue. However, | |
| 439 * if the handler for SIGCHLD is SIG_IGN, the system reaps | |
| 440 * zombie processes for us, and we don't get any notification. | |
| 441 * This appears to be the only signal with this quirk. */ | |
| 442 if (_evsig_set_handler(base, nsignal, | |
| 443 nsignal == SIGCHLD ? SIG_DFL : SIG_IGN) == -1) { | |
| 444 return (-1); | |
| 445 } | |
| 446 | |
| 447 return (0); | |
| 448 } | |
| 449 | |
| 450 static int | |
| 451 kq_sig_del(struct event_base *base, int nsignal, short old, short events, void *p) | |
| 452 { | |
| 453 struct kqop *kqop = base->evbase; | |
| 454 struct kevent kev; | |
| 455 | |
| 456 struct timespec timeout = { 0, 0 }; | |
| 457 (void)p; | |
| 458 | |
| 459 EVUTIL_ASSERT(nsignal >= 0 && nsignal < NSIG); | |
| 460 | |
| 461 memset(&kev, 0, sizeof(kev)); | |
| 462 kev.ident = nsignal; | |
| 463 kev.filter = EVFILT_SIGNAL; | |
| 464 kev.flags = EV_DELETE; | |
| 465 | |
| 466 /* Because we insert signal events | |
| 467 * immediately, we need to delete them | |
| 468 * immediately, too */ | |
| 469 if (kevent(kqop->kq, &kev, 1, NULL, 0, &timeout) == -1) | |
| 470 return (-1); | |
| 471 | |
| 472 if (_evsig_restore_handler(base, nsignal) == -1) | |
| 473 return (-1); | |
| 474 | |
| 475 return (0); | |
| 476 } |
