Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 1 | /* $OpenBSD: poll.c,v 1.2 2002/06/25 15:50:15 mickey 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" |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 30 | #include "evconfig-private.h" |
| 31 | |
| 32 | #ifdef EVENT__HAVE_POLL |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 33 | |
| 34 | #include <sys/types.h> |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 35 | #ifdef EVENT__HAVE_SYS_TIME_H |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 36 | #include <sys/time.h> |
| 37 | #endif |
| 38 | #include <sys/queue.h> |
| 39 | #include <poll.h> |
| 40 | #include <signal.h> |
| 41 | #include <limits.h> |
| 42 | #include <stdio.h> |
| 43 | #include <stdlib.h> |
| 44 | #include <string.h> |
| 45 | #include <unistd.h> |
| 46 | #include <errno.h> |
| 47 | |
| 48 | #include "event-internal.h" |
| 49 | #include "evsignal-internal.h" |
| 50 | #include "log-internal.h" |
| 51 | #include "evmap-internal.h" |
| 52 | #include "event2/thread.h" |
| 53 | #include "evthread-internal.h" |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 54 | #include "time-internal.h" |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 55 | |
| 56 | struct pollidx { |
| 57 | int idxplus1; |
| 58 | }; |
| 59 | |
| 60 | struct pollop { |
| 61 | int event_count; /* Highest number alloc */ |
| 62 | int nfds; /* Highest number used */ |
| 63 | int realloc_copy; /* True iff we must realloc |
| 64 | * event_set_copy */ |
| 65 | struct pollfd *event_set; |
| 66 | struct pollfd *event_set_copy; |
| 67 | }; |
| 68 | |
| 69 | static void *poll_init(struct event_base *); |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 70 | static int poll_add(struct event_base *, int, short old, short events, void *idx); |
| 71 | static int poll_del(struct event_base *, int, short old, short events, void *idx); |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 72 | static int poll_dispatch(struct event_base *, struct timeval *); |
| 73 | static void poll_dealloc(struct event_base *); |
| 74 | |
| 75 | const struct eventop pollops = { |
| 76 | "poll", |
| 77 | poll_init, |
| 78 | poll_add, |
| 79 | poll_del, |
| 80 | poll_dispatch, |
| 81 | poll_dealloc, |
| 82 | 0, /* doesn't need_reinit */ |
| 83 | EV_FEATURE_FDS, |
| 84 | sizeof(struct pollidx), |
| 85 | }; |
| 86 | |
| 87 | static void * |
| 88 | poll_init(struct event_base *base) |
| 89 | { |
| 90 | struct pollop *pollop; |
| 91 | |
| 92 | if (!(pollop = mm_calloc(1, sizeof(struct pollop)))) |
| 93 | return (NULL); |
| 94 | |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 95 | evsig_init_(base); |
| 96 | |
| 97 | evutil_weakrand_seed_(&base->weakrand_seed, 0); |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 98 | |
| 99 | return (pollop); |
| 100 | } |
| 101 | |
| 102 | #ifdef CHECK_INVARIANTS |
| 103 | static void |
| 104 | poll_check_ok(struct pollop *pop) |
| 105 | { |
| 106 | int i, idx; |
| 107 | struct event *ev; |
| 108 | |
| 109 | for (i = 0; i < pop->fd_count; ++i) { |
| 110 | idx = pop->idxplus1_by_fd[i]-1; |
| 111 | if (idx < 0) |
| 112 | continue; |
| 113 | EVUTIL_ASSERT(pop->event_set[idx].fd == i); |
| 114 | } |
| 115 | for (i = 0; i < pop->nfds; ++i) { |
| 116 | struct pollfd *pfd = &pop->event_set[i]; |
| 117 | EVUTIL_ASSERT(pop->idxplus1_by_fd[pfd->fd] == i+1); |
| 118 | } |
| 119 | } |
| 120 | #else |
| 121 | #define poll_check_ok(pop) |
| 122 | #endif |
| 123 | |
| 124 | static int |
| 125 | poll_dispatch(struct event_base *base, struct timeval *tv) |
| 126 | { |
| 127 | int res, i, j, nfds; |
| 128 | long msec = -1; |
| 129 | struct pollop *pop = base->evbase; |
| 130 | struct pollfd *event_set; |
| 131 | |
| 132 | poll_check_ok(pop); |
| 133 | |
| 134 | nfds = pop->nfds; |
| 135 | |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 136 | #ifndef EVENT__DISABLE_THREAD_SUPPORT |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 137 | if (base->th_base_lock) { |
| 138 | /* If we're using this backend in a multithreaded setting, |
| 139 | * then we need to work on a copy of event_set, so that we can |
| 140 | * let other threads modify the main event_set while we're |
| 141 | * polling. If we're not multithreaded, then we'll skip the |
| 142 | * copy step here to save memory and time. */ |
| 143 | if (pop->realloc_copy) { |
| 144 | struct pollfd *tmp = mm_realloc(pop->event_set_copy, |
| 145 | pop->event_count * sizeof(struct pollfd)); |
| 146 | if (tmp == NULL) { |
| 147 | event_warn("realloc"); |
| 148 | return -1; |
| 149 | } |
| 150 | pop->event_set_copy = tmp; |
| 151 | pop->realloc_copy = 0; |
| 152 | } |
| 153 | memcpy(pop->event_set_copy, pop->event_set, |
| 154 | sizeof(struct pollfd)*nfds); |
| 155 | event_set = pop->event_set_copy; |
| 156 | } else { |
| 157 | event_set = pop->event_set; |
| 158 | } |
| 159 | #else |
| 160 | event_set = pop->event_set; |
| 161 | #endif |
| 162 | |
| 163 | if (tv != NULL) { |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 164 | msec = evutil_tv_to_msec_(tv); |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 165 | if (msec < 0 || msec > INT_MAX) |
| 166 | msec = INT_MAX; |
| 167 | } |
| 168 | |
| 169 | EVBASE_RELEASE_LOCK(base, th_base_lock); |
| 170 | |
| 171 | res = poll(event_set, nfds, msec); |
| 172 | |
| 173 | EVBASE_ACQUIRE_LOCK(base, th_base_lock); |
| 174 | |
| 175 | if (res == -1) { |
| 176 | if (errno != EINTR) { |
| 177 | event_warn("poll"); |
| 178 | return (-1); |
| 179 | } |
| 180 | |
| 181 | return (0); |
| 182 | } |
| 183 | |
| 184 | event_debug(("%s: poll reports %d", __func__, res)); |
| 185 | |
| 186 | if (res == 0 || nfds == 0) |
| 187 | return (0); |
| 188 | |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 189 | i = evutil_weakrand_range_(&base->weakrand_seed, nfds); |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 190 | for (j = 0; j < nfds; j++) { |
| 191 | int what; |
| 192 | if (++i == nfds) |
| 193 | i = 0; |
| 194 | what = event_set[i].revents; |
| 195 | if (!what) |
| 196 | continue; |
| 197 | |
| 198 | res = 0; |
| 199 | |
| 200 | /* If the file gets closed notify */ |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 201 | if (what & (POLLHUP|POLLERR|POLLNVAL)) |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 202 | what |= POLLIN|POLLOUT; |
| 203 | if (what & POLLIN) |
| 204 | res |= EV_READ; |
| 205 | if (what & POLLOUT) |
| 206 | res |= EV_WRITE; |
| 207 | if (res == 0) |
| 208 | continue; |
| 209 | |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 210 | evmap_io_active_(base, event_set[i].fd, res); |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 211 | } |
| 212 | |
| 213 | return (0); |
| 214 | } |
| 215 | |
| 216 | static int |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 217 | poll_add(struct event_base *base, int fd, short old, short events, void *idx_) |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 218 | { |
| 219 | struct pollop *pop = base->evbase; |
| 220 | struct pollfd *pfd = NULL; |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 221 | struct pollidx *idx = idx_; |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 222 | int i; |
| 223 | |
| 224 | EVUTIL_ASSERT((events & EV_SIGNAL) == 0); |
| 225 | if (!(events & (EV_READ|EV_WRITE))) |
| 226 | return (0); |
| 227 | |
| 228 | poll_check_ok(pop); |
| 229 | if (pop->nfds + 1 >= pop->event_count) { |
| 230 | struct pollfd *tmp_event_set; |
| 231 | int tmp_event_count; |
| 232 | |
| 233 | if (pop->event_count < 32) |
| 234 | tmp_event_count = 32; |
| 235 | else |
| 236 | tmp_event_count = pop->event_count * 2; |
| 237 | |
| 238 | /* We need more file descriptors */ |
| 239 | tmp_event_set = mm_realloc(pop->event_set, |
| 240 | tmp_event_count * sizeof(struct pollfd)); |
| 241 | if (tmp_event_set == NULL) { |
| 242 | event_warn("realloc"); |
| 243 | return (-1); |
| 244 | } |
| 245 | pop->event_set = tmp_event_set; |
| 246 | |
| 247 | pop->event_count = tmp_event_count; |
| 248 | pop->realloc_copy = 1; |
| 249 | } |
| 250 | |
| 251 | i = idx->idxplus1 - 1; |
| 252 | |
| 253 | if (i >= 0) { |
| 254 | pfd = &pop->event_set[i]; |
| 255 | } else { |
| 256 | i = pop->nfds++; |
| 257 | pfd = &pop->event_set[i]; |
| 258 | pfd->events = 0; |
| 259 | pfd->fd = fd; |
| 260 | idx->idxplus1 = i + 1; |
| 261 | } |
| 262 | |
| 263 | pfd->revents = 0; |
| 264 | if (events & EV_WRITE) |
| 265 | pfd->events |= POLLOUT; |
| 266 | if (events & EV_READ) |
| 267 | pfd->events |= POLLIN; |
| 268 | poll_check_ok(pop); |
| 269 | |
| 270 | return (0); |
| 271 | } |
| 272 | |
| 273 | /* |
| 274 | * Nothing to be done here. |
| 275 | */ |
| 276 | |
| 277 | static int |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 278 | poll_del(struct event_base *base, int fd, short old, short events, void *idx_) |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 279 | { |
| 280 | struct pollop *pop = base->evbase; |
| 281 | struct pollfd *pfd = NULL; |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 282 | struct pollidx *idx = idx_; |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 283 | int i; |
| 284 | |
| 285 | EVUTIL_ASSERT((events & EV_SIGNAL) == 0); |
| 286 | if (!(events & (EV_READ|EV_WRITE))) |
| 287 | return (0); |
| 288 | |
| 289 | poll_check_ok(pop); |
| 290 | i = idx->idxplus1 - 1; |
| 291 | if (i < 0) |
| 292 | return (-1); |
| 293 | |
| 294 | /* Do we still want to read or write? */ |
| 295 | pfd = &pop->event_set[i]; |
| 296 | if (events & EV_READ) |
| 297 | pfd->events &= ~POLLIN; |
| 298 | if (events & EV_WRITE) |
| 299 | pfd->events &= ~POLLOUT; |
| 300 | poll_check_ok(pop); |
| 301 | if (pfd->events) |
| 302 | /* Another event cares about that fd. */ |
| 303 | return (0); |
| 304 | |
| 305 | /* Okay, so we aren't interested in that fd anymore. */ |
| 306 | idx->idxplus1 = 0; |
| 307 | |
| 308 | --pop->nfds; |
| 309 | if (i != pop->nfds) { |
| 310 | /* |
| 311 | * Shift the last pollfd down into the now-unoccupied |
| 312 | * position. |
| 313 | */ |
| 314 | memcpy(&pop->event_set[i], &pop->event_set[pop->nfds], |
| 315 | sizeof(struct pollfd)); |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 316 | idx = evmap_io_get_fdinfo_(&base->io, pop->event_set[i].fd); |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 317 | EVUTIL_ASSERT(idx); |
| 318 | EVUTIL_ASSERT(idx->idxplus1 == pop->nfds + 1); |
| 319 | idx->idxplus1 = i + 1; |
| 320 | } |
| 321 | |
| 322 | poll_check_ok(pop); |
| 323 | return (0); |
| 324 | } |
| 325 | |
| 326 | static void |
| 327 | poll_dealloc(struct event_base *base) |
| 328 | { |
| 329 | struct pollop *pop = base->evbase; |
| 330 | |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 331 | evsig_dealloc_(base); |
Christopher Wiley | e867981 | 2015-07-01 13:36:18 -0700 | [diff] [blame] | 332 | if (pop->event_set) |
| 333 | mm_free(pop->event_set); |
| 334 | if (pop->event_set_copy) |
| 335 | mm_free(pop->event_set_copy); |
| 336 | |
| 337 | memset(pop, 0, sizeof(struct pollop)); |
| 338 | mm_free(pop); |
| 339 | } |
Narayan Kamath | fc74cb4 | 2017-09-13 12:53:52 +0100 | [diff] [blame] | 340 | |
| 341 | #endif /* EVENT__HAVE_POLL */ |