ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libev/ev_epoll.c
(Generate patch)

Comparing libev/ev_epoll.c (file contents):
Revision 1.59 by root, Mon Jan 17 12:11:12 2011 UTC vs.
Revision 1.72 by root, Wed Jun 21 14:42:30 2017 UTC

4 * Copyright (c) 2007,2008,2009,2010,2011 Marc Alexander Lehmann <libev@schmorp.de> 4 * Copyright (c) 2007,2008,2009,2010,2011 Marc Alexander Lehmann <libev@schmorp.de>
5 * All rights reserved. 5 * All rights reserved.
6 * 6 *
7 * Redistribution and use in source and binary forms, with or without modifica- 7 * Redistribution and use in source and binary forms, with or without modifica-
8 * tion, are permitted provided that the following conditions are met: 8 * tion, are permitted provided that the following conditions are met:
9 * 9 *
10 * 1. Redistributions of source code must retain the above copyright notice, 10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer. 11 * this list of conditions and the following disclaimer.
12 * 12 *
13 * 2. Redistributions in binary form must reproduce the above copyright 13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the 14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution. 15 * documentation and/or other materials provided with the distribution.
16 * 16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- 18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- 20 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
142epoll_poll (EV_P_ ev_tstamp timeout) 142epoll_poll (EV_P_ ev_tstamp timeout)
143{ 143{
144 int i; 144 int i;
145 int eventcnt; 145 int eventcnt;
146 146
147 if (expect_false (epoll_epermcnt))
148 timeout = 0.;
149
147 /* epoll wait times cannot be larger than (LONG_MAX - 999UL) / HZ msecs, which is below */ 150 /* epoll wait times cannot be larger than (LONG_MAX - 999UL) / HZ msecs, which is below */
148 /* the default libev max wait time, however. */ 151 /* the default libev max wait time, however. */
149 EV_RELEASE_CB; 152 EV_RELEASE_CB;
150 eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, 153 eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, timeout * 1e3);
151 epoll_epermcnt ? 0 : ev_timeout_to_ms (timeout));
152 EV_ACQUIRE_CB; 154 EV_ACQUIRE_CB;
153 155
154 if (expect_false (eventcnt < 0)) 156 if (expect_false (eventcnt < 0))
155 { 157 {
156 if (errno != EINTR) 158 if (errno != EINTR)
166 int fd = (uint32_t)ev->data.u64; /* mask out the lower 32 bits */ 168 int fd = (uint32_t)ev->data.u64; /* mask out the lower 32 bits */
167 int want = anfds [fd].events; 169 int want = anfds [fd].events;
168 int got = (ev->events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0) 170 int got = (ev->events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0)
169 | (ev->events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0); 171 | (ev->events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0);
170 172
173 /*
171 /* check for spurious notification */ 174 * check for spurious notification.
175 * this only finds spurious notifications on egen updates
176 * other spurious notifications will be found by epoll_ctl, below
172 /* we assume that fd is always in range, as we never shrink the anfds array */ 177 * we assume that fd is always in range, as we never shrink the anfds array
178 */
173 if (expect_false ((uint32_t)anfds [fd].egen != (uint32_t)(ev->data.u64 >> 32))) 179 if (expect_false ((uint32_t)anfds [fd].egen != (uint32_t)(ev->data.u64 >> 32)))
174 { 180 {
175 /* recreate kernel state */ 181 /* recreate kernel state */
176 postfork = 1; 182 postfork |= 2;
177 continue; 183 continue;
178 } 184 }
179 185
180 if (expect_false (got & ~want)) 186 if (expect_false (got & ~want))
181 { 187 {
182 anfds [fd].emask = want; 188 anfds [fd].emask = want;
183 189
190 /*
184 /* we received an event but are not interested in it, try mod or del */ 191 * we received an event but are not interested in it, try mod or del
185 /* I don't think we ever need MOD, but let's handle it anyways */ 192 * this often happens because we optimistically do not unregister fds
193 * when we are no longer interested in them, but also when we get spurious
194 * notifications for fds from another process. this is partially handled
195 * above with the gencounter check (== our fd is not the event fd), and
196 * partially here, when epoll_ctl returns an error (== a child has the fd
197 * but we closed it).
198 */
186 ev->events = (want & EV_READ ? EPOLLIN : 0) 199 ev->events = (want & EV_READ ? EPOLLIN : 0)
187 | (want & EV_WRITE ? EPOLLOUT : 0); 200 | (want & EV_WRITE ? EPOLLOUT : 0);
188 201
189 /* pre-2.6.9 kernels require a non-null pointer with EPOLL_CTL_DEL, */ 202 /* pre-2.6.9 kernels require a non-null pointer with EPOLL_CTL_DEL, */
190 /* which is fortunately easy to do for us. */ 203 /* which is fortunately easy to do for us. */
191 if (epoll_ctl (backend_fd, want ? EPOLL_CTL_MOD : EPOLL_CTL_DEL, fd, ev)) 204 if (epoll_ctl (backend_fd, want ? EPOLL_CTL_MOD : EPOLL_CTL_DEL, fd, ev))
192 { 205 {
193 postfork = 1; /* an error occurred, recreate kernel state */ 206 postfork |= 2; /* an error occurred, recreate kernel state */
194 continue; 207 continue;
195 } 208 }
196 } 209 }
197 210
198 fd_event (EV_A_ fd, got); 211 fd_event (EV_A_ fd, got);
213 unsigned char events = anfds [fd].events & (EV_READ | EV_WRITE); 226 unsigned char events = anfds [fd].events & (EV_READ | EV_WRITE);
214 227
215 if (anfds [fd].emask & EV_EMASK_EPERM && events) 228 if (anfds [fd].emask & EV_EMASK_EPERM && events)
216 fd_event (EV_A_ fd, events); 229 fd_event (EV_A_ fd, events);
217 else 230 else
231 {
218 epoll_eperms [i] = epoll_eperms [--epoll_epermcnt]; 232 epoll_eperms [i] = epoll_eperms [--epoll_epermcnt];
233 anfds [fd].emask = 0;
234 }
219 } 235 }
220} 236}
221 237
222int inline_size 238inline_size
239int
223epoll_init (EV_P_ int flags) 240epoll_init (EV_P_ int flags)
224{ 241{
225#ifdef EPOLL_CLOEXEC 242#if defined EPOLL_CLOEXEC && !defined __ANDROID__
226 backend_fd = epoll_create1 (EPOLL_CLOEXEC); 243 backend_fd = epoll_create1 (EPOLL_CLOEXEC);
227 244
228 if (backend_fd <= 0) 245 if (backend_fd < 0 && (errno == EINVAL || errno == ENOSYS))
229#endif 246#endif
230 backend_fd = epoll_create (256); 247 backend_fd = epoll_create (256);
231 248
232 if (backend_fd < 0) 249 if (backend_fd < 0)
233 return 0; 250 return 0;
234 251
235 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); 252 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
236 253
237 backend_fudge = 0.; /* kernel sources seem to indicate this to be zero */ 254 backend_mintime = 1e-3; /* epoll does sometimes return early, this is just to avoid the worst */
238 backend_modify = epoll_modify; 255 backend_modify = epoll_modify;
239 backend_poll = epoll_poll; 256 backend_poll = epoll_poll;
240 257
241 epoll_eventmax = 64; /* initial number of events receivable per poll */ 258 epoll_eventmax = 64; /* initial number of events receivable per poll */
242 epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); 259 epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax);
243 260
244 return EVBACKEND_EPOLL; 261 return EVBACKEND_EPOLL;
245} 262}
246 263
247void inline_size 264inline_size
265void
248epoll_destroy (EV_P) 266epoll_destroy (EV_P)
249{ 267{
250 ev_free (epoll_events); 268 ev_free (epoll_events);
251 array_free (epoll_eperm, EMPTY); 269 array_free (epoll_eperm, EMPTY);
252} 270}
253 271
254void inline_size 272inline_size
273void
255epoll_fork (EV_P) 274epoll_fork (EV_P)
256{ 275{
257 close (backend_fd); 276 close (backend_fd);
258 277
259 while ((backend_fd = epoll_create (256)) < 0) 278 while ((backend_fd = epoll_create (256)) < 0)

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines