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| 1 /* $OpenBSD: select.c,v 1.2 2002/06/25 15:50:15 mickey Exp $ */ | |
| 2 | |
| 3 /* | |
| 4 * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu> | |
| 5 * All rights reserved. | |
| 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 #ifdef HAVE_CONFIG_H | |
| 30 #include "config.h" | |
| 31 #endif | |
| 32 | |
| 33 #ifdef WIN32 | |
| 34 #define WIN32_LEAN_AND_MEAN | |
| 35 #include <winsock2.h> | |
| 36 #include <windows.h> | |
| 37 #undef WIN32_LEAN_AND_MEAN | |
| 38 #endif | |
| 39 #include <sys/types.h> | |
| 40 #ifdef HAVE_SYS_TIME_H | |
| 41 #include <sys/time.h> | |
| 42 #endif | |
| 43 #include <sys/queue.h> | |
| 44 #ifdef HAVE_SYS_SOCKET_H | |
| 45 #include <sys/socket.h> | |
| 46 #endif | |
| 47 #include <signal.h> | |
| 48 #include <stdio.h> | |
| 49 #include <stdlib.h> | |
| 50 #include <string.h> | |
| 51 #ifdef HAVE_UNISTD_H | |
| 52 #include <unistd.h> | |
| 53 #endif | |
| 54 #include <errno.h> | |
| 55 #ifdef HAVE_FCNTL_H | |
| 56 #include <fcntl.h> | |
| 57 #endif | |
| 58 #include <assert.h> | |
| 59 | |
| 60 #include "event.h" | |
| 61 #include "event-internal.h" | |
| 62 #include "evsignal.h" | |
| 63 #include "evutil.h" | |
| 64 #include "log.h" | |
| 65 | |
| 66 struct event_base *evsignal_base = NULL; | |
| 67 | |
| 68 static void evsignal_handler(int sig); | |
| 69 | |
| 70 #ifdef WIN32 | |
| 71 #define error_is_eagain(err) \ | |
| 72 ((err) == EAGAIN || (err) == WSAEWOULDBLOCK) | |
| 73 #else | |
| 74 #define error_is_eagain(err) ((err) == EAGAIN) | |
| 75 #endif | |
| 76 | |
| 77 /* Callback for when the signal handler write a byte to our signaling socket */ | |
| 78 static void | |
| 79 evsignal_cb(int fd, short what, void *arg) | |
| 80 { | |
| 81 static char signals[1]; | |
| 82 #ifdef WIN32 | |
| 83 SSIZE_T n; | |
| 84 #else | |
| 85 ssize_t n; | |
| 86 #endif | |
| 87 | |
| 88 n = recv(fd, signals, sizeof(signals), 0); | |
| 89 if (n == -1) { | |
| 90 int err = EVUTIL_SOCKET_ERROR(); | |
| 91 if (! error_is_eagain(err)) | |
| 92 event_err(1, "%s: read", __func__); | |
| 93 } | |
| 94 } | |
| 95 | |
| 96 #ifdef HAVE_SETFD | |
| 97 #define FD_CLOSEONEXEC(x) do { \ | |
| 98 if (fcntl(x, F_SETFD, 1) == -1) \ | |
| 99 event_warn("fcntl(%d, F_SETFD)", x); \ | |
| 100 } while (0) | |
| 101 #else | |
| 102 #define FD_CLOSEONEXEC(x) | |
| 103 #endif | |
| 104 | |
| 105 int | |
| 106 evsignal_init(struct event_base *base) | |
| 107 { | |
| 108 int i; | |
| 109 | |
| 110 /* | |
| 111 * Our signal handler is going to write to one end of the socket | |
| 112 * pair to wake up our event loop. The event loop then scans for | |
| 113 * signals that got delivered. | |
| 114 */ | |
| 115 if (evutil_socketpair( | |
| 116 AF_UNIX, SOCK_STREAM, 0, base->sig.ev_signal_pair) == -1) { | |
| 117 #ifdef WIN32 | |
| 118 /* Make this nonfatal on win32, where sometimes people | |
| 119 have localhost firewalled. */ | |
| 120 event_warn("%s: socketpair", __func__); | |
| 121 #else | |
| 122 event_err(1, "%s: socketpair", __func__); | |
| 123 #endif | |
| 124 return -1; | |
| 125 } | |
| 126 | |
| 127 FD_CLOSEONEXEC(base->sig.ev_signal_pair[0]); | |
| 128 FD_CLOSEONEXEC(base->sig.ev_signal_pair[1]); | |
| 129 base->sig.sh_old = NULL; | |
| 130 base->sig.sh_old_max = 0; | |
| 131 base->sig.evsignal_caught = 0; | |
| 132 memset(&base->sig.evsigcaught, 0, sizeof(sig_atomic_t)*NSIG); | |
| 133 /* initialize the queues for all events */ | |
| 134 for (i = 0; i < NSIG; ++i) | |
| 135 TAILQ_INIT(&base->sig.evsigevents[i]); | |
| 136 | |
| 137 evutil_make_socket_nonblocking(base->sig.ev_signal_pair[0]); | |
| 138 evutil_make_socket_nonblocking(base->sig.ev_signal_pair[1]); | |
| 139 | |
| 140 event_set(&base->sig.ev_signal, base->sig.ev_signal_pair[1], | |
| 141 EV_READ | EV_PERSIST, evsignal_cb, &base->sig.ev_signal); | |
| 142 base->sig.ev_signal.ev_base = base; | |
| 143 base->sig.ev_signal.ev_flags |= EVLIST_INTERNAL; | |
| 144 | |
| 145 return 0; | |
| 146 } | |
| 147 | |
| 148 /* Helper: set the signal handler for evsignal to handler in base, so that | |
| 149 * we can restore the original handler when we clear the current one. */ | |
| 150 int | |
| 151 _evsignal_set_handler(struct event_base *base, | |
| 152 int evsignal, void (*handler)(int)) | |
| 153 { | |
| 154 #ifdef HAVE_SIGACTION | |
| 155 struct sigaction sa; | |
| 156 #else | |
| 157 ev_sighandler_t sh; | |
| 158 #endif | |
| 159 struct evsignal_info *sig = &base->sig; | |
| 160 void *p; | |
| 161 | |
| 162 /* | |
| 163 * resize saved signal handler array up to the highest signal number. | |
| 164 * a dynamic array is used to keep footprint on the low side. | |
| 165 */ | |
| 166 if (evsignal >= sig->sh_old_max) { | |
| 167 int new_max = evsignal + 1; | |
| 168 event_debug(("%s: evsignal (%d) >= sh_old_max (%d), resizing", | |
| 169 __func__, evsignal, sig->sh_old_max)); | |
| 170 p = realloc(sig->sh_old, new_max * sizeof(*sig->sh_old)); | |
| 171 if (p == NULL) { | |
| 172 event_warn("realloc"); | |
| 173 return (-1); | |
| 174 } | |
| 175 | |
| 176 memset((char *)p + sig->sh_old_max * sizeof(*sig->sh_old), | |
| 177 0, (new_max - sig->sh_old_max) * sizeof(*sig->sh_old)); | |
| 178 | |
| 179 sig->sh_old_max = new_max; | |
| 180 sig->sh_old = p; | |
| 181 } | |
| 182 | |
| 183 /* allocate space for previous handler out of dynamic array */ | |
| 184 sig->sh_old[evsignal] = malloc(sizeof *sig->sh_old[evsignal]); | |
| 185 if (sig->sh_old[evsignal] == NULL) { | |
| 186 event_warn("malloc"); | |
| 187 return (-1); | |
| 188 } | |
| 189 | |
| 190 /* save previous handler and setup new handler */ | |
| 191 #ifdef HAVE_SIGACTION | |
| 192 memset(&sa, 0, sizeof(sa)); | |
| 193 sa.sa_handler = handler; | |
| 194 sa.sa_flags |= SA_RESTART; | |
| 195 sigfillset(&sa.sa_mask); | |
| 196 | |
| 197 if (sigaction(evsignal, &sa, sig->sh_old[evsignal]) == -1) { | |
| 198 event_warn("sigaction"); | |
| 199 free(sig->sh_old[evsignal]); | |
| 200 sig->sh_old[evsignal] = NULL; | |
| 201 return (-1); | |
| 202 } | |
| 203 #else | |
| 204 if ((sh = signal(evsignal, handler)) == SIG_ERR) { | |
| 205 event_warn("signal"); | |
| 206 free(sig->sh_old[evsignal]); | |
| 207 sig->sh_old[evsignal] = NULL; | |
| 208 return (-1); | |
| 209 } | |
| 210 *sig->sh_old[evsignal] = sh; | |
| 211 #endif | |
| 212 | |
| 213 return (0); | |
| 214 } | |
| 215 | |
| 216 int | |
| 217 evsignal_add(struct event *ev) | |
| 218 { | |
| 219 int evsignal; | |
| 220 struct event_base *base = ev->ev_base; | |
| 221 struct evsignal_info *sig = &ev->ev_base->sig; | |
| 222 | |
| 223 if (ev->ev_events & (EV_READ|EV_WRITE)) | |
| 224 event_errx(1, "%s: EV_SIGNAL incompatible use", __func__); | |
| 225 evsignal = EVENT_SIGNAL(ev); | |
| 226 assert(evsignal >= 0 && evsignal < NSIG); | |
| 227 if (TAILQ_EMPTY(&sig->evsigevents[evsignal])) { | |
| 228 event_debug(("%s: %p: changing signal handler", __func__, ev)); | |
| 229 if (_evsignal_set_handler( | |
| 230 base, evsignal, evsignal_handler) == -1) | |
| 231 return (-1); | |
| 232 | |
| 233 /* catch signals if they happen quickly */ | |
| 234 evsignal_base = base; | |
| 235 | |
| 236 if (!sig->ev_signal_added) { | |
| 237 if (event_add(&sig->ev_signal, NULL)) | |
| 238 return (-1); | |
| 239 sig->ev_signal_added = 1; | |
| 240 } | |
| 241 } | |
| 242 | |
| 243 /* multiple events may listen to the same signal */ | |
| 244 TAILQ_INSERT_TAIL(&sig->evsigevents[evsignal], ev, ev_signal_next); | |
| 245 | |
| 246 return (0); | |
| 247 } | |
| 248 | |
| 249 int | |
| 250 _evsignal_restore_handler(struct event_base *base, int evsignal) | |
| 251 { | |
| 252 int ret = 0; | |
| 253 struct evsignal_info *sig = &base->sig; | |
| 254 #ifdef HAVE_SIGACTION | |
| 255 struct sigaction *sh; | |
| 256 #else | |
| 257 ev_sighandler_t *sh; | |
| 258 #endif | |
| 259 | |
| 260 /* restore previous handler */ | |
| 261 sh = sig->sh_old[evsignal]; | |
| 262 sig->sh_old[evsignal] = NULL; | |
| 263 #ifdef HAVE_SIGACTION | |
| 264 if (sigaction(evsignal, sh, NULL) == -1) { | |
| 265 event_warn("sigaction"); | |
| 266 ret = -1; | |
| 267 } | |
| 268 #else | |
| 269 if (signal(evsignal, *sh) == SIG_ERR) { | |
| 270 event_warn("signal"); | |
| 271 ret = -1; | |
| 272 } | |
| 273 #endif | |
| 274 free(sh); | |
| 275 | |
| 276 return ret; | |
| 277 } | |
| 278 | |
| 279 int | |
| 280 evsignal_del(struct event *ev) | |
| 281 { | |
| 282 struct event_base *base = ev->ev_base; | |
| 283 struct evsignal_info *sig = &base->sig; | |
| 284 int evsignal = EVENT_SIGNAL(ev); | |
| 285 | |
| 286 assert(evsignal >= 0 && evsignal < NSIG); | |
| 287 | |
| 288 /* multiple events may listen to the same signal */ | |
| 289 TAILQ_REMOVE(&sig->evsigevents[evsignal], ev, ev_signal_next); | |
| 290 | |
| 291 if (!TAILQ_EMPTY(&sig->evsigevents[evsignal])) | |
| 292 return (0); | |
| 293 | |
| 294 event_debug(("%s: %p: restoring signal handler", __func__, ev)); | |
| 295 | |
| 296 return (_evsignal_restore_handler(ev->ev_base, EVENT_SIGNAL(ev))); | |
| 297 } | |
| 298 | |
| 299 static void | |
| 300 evsignal_handler(int sig) | |
| 301 { | |
| 302 int save_errno = errno; | |
| 303 | |
| 304 if (evsignal_base == NULL) { | |
| 305 event_warn( | |
| 306 "%s: received signal %d, but have no base configured", | |
| 307 __func__, sig); | |
| 308 return; | |
| 309 } | |
| 310 | |
| 311 evsignal_base->sig.evsigcaught[sig]++; | |
| 312 evsignal_base->sig.evsignal_caught = 1; | |
| 313 | |
| 314 #ifndef HAVE_SIGACTION | |
| 315 signal(sig, evsignal_handler); | |
| 316 #endif | |
| 317 | |
| 318 /* Wake up our notification mechanism */ | |
| 319 send(evsignal_base->sig.ev_signal_pair[0], "a", 1, 0); | |
| 320 errno = save_errno; | |
| 321 } | |
| 322 | |
| 323 void | |
| 324 evsignal_process(struct event_base *base) | |
| 325 { | |
| 326 struct evsignal_info *sig = &base->sig; | |
| 327 struct event *ev, *next_ev; | |
| 328 sig_atomic_t ncalls; | |
| 329 int i; | |
| 330 | |
| 331 base->sig.evsignal_caught = 0; | |
| 332 for (i = 1; i < NSIG; ++i) { | |
| 333 ncalls = sig->evsigcaught[i]; | |
| 334 if (ncalls == 0) | |
| 335 continue; | |
| 336 sig->evsigcaught[i] -= ncalls; | |
| 337 | |
| 338 for (ev = TAILQ_FIRST(&sig->evsigevents[i]); | |
| 339 ev != NULL; ev = next_ev) { | |
| 340 next_ev = TAILQ_NEXT(ev, ev_signal_next); | |
| 341 if (!(ev->ev_events & EV_PERSIST)) | |
| 342 event_del(ev); | |
| 343 event_active(ev, EV_SIGNAL, ncalls); | |
| 344 } | |
| 345 | |
| 346 } | |
| 347 } | |
| 348 | |
| 349 void | |
| 350 evsignal_dealloc(struct event_base *base) | |
| 351 { | |
| 352 int i = 0; | |
| 353 if (base->sig.ev_signal_added) { | |
| 354 event_del(&base->sig.ev_signal); | |
| 355 base->sig.ev_signal_added = 0; | |
| 356 } | |
| 357 for (i = 0; i < NSIG; ++i) { | |
| 358 if (i < base->sig.sh_old_max && base->sig.sh_old[i] != NULL) | |
| 359 _evsignal_restore_handler(base, i); | |
| 360 } | |
| 361 | |
| 362 if (base->sig.ev_signal_pair[0] != -1) { | |
| 363 EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[0]); | |
| 364 base->sig.ev_signal_pair[0] = -1; | |
| 365 } | |
| 366 if (base->sig.ev_signal_pair[1] != -1) { | |
| 367 EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[1]); | |
| 368 base->sig.ev_signal_pair[1] = -1; | |
| 369 } | |
| 370 base->sig.sh_old_max = 0; | |
| 371 | |
| 372 /* per index frees are handled in evsig_del() */ | |
| 373 if (base->sig.sh_old) { | |
| 374 free(base->sig.sh_old); | |
| 375 base->sig.sh_old = NULL; | |
| 376 } | |
| 377 } | |
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Chromium Code Reviews
Issue 1531573008:
move libevent into base (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master