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 1.62 by root, Sat Jun 4 05:25:03 2011 UTC vs.
Revision 1.73 by root, Thu Jun 20 22:44:59 2019 UTC

1/* 1/*
2 * libev epoll fd activity backend 2 * libev epoll fd activity backend
3 * 3 *
4 * Copyright (c) 2007,2008,2009,2010,2011 Marc Alexander Lehmann <libev@schmorp.de> 4 * Copyright (c) 2007,2008,2009,2010,2011,2016,2017,2019 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 *
122 anfds [fd].emask = EV_EMASK_EPERM; 122 anfds [fd].emask = EV_EMASK_EPERM;
123 123
124 /* add fd to epoll_eperms, if not already inside */ 124 /* add fd to epoll_eperms, if not already inside */
125 if (!(oldmask & EV_EMASK_EPERM)) 125 if (!(oldmask & EV_EMASK_EPERM))
126 { 126 {
127 array_needsize (int, epoll_eperms, epoll_epermmax, epoll_epermcnt + 1, EMPTY2); 127 array_needsize (int, epoll_eperms, epoll_epermmax, epoll_epermcnt + 1, array_needsize_noinit);
128 epoll_eperms [epoll_epermcnt++] = fd; 128 epoll_eperms [epoll_epermcnt++] = fd;
129 } 129 }
130 130
131 return; 131 return;
132 } 132 }
168 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 */
169 int want = anfds [fd].events; 169 int want = anfds [fd].events;
170 int got = (ev->events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0) 170 int got = (ev->events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0)
171 | (ev->events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0); 171 | (ev->events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0);
172 172
173 /*
173 /* 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
174 /* 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 */
175 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)))
176 { 180 {
177 /* recreate kernel state */ 181 /* recreate kernel state */
178 postfork = 1; 182 postfork |= 2;
179 continue; 183 continue;
180 } 184 }
181 185
182 if (expect_false (got & ~want)) 186 if (expect_false (got & ~want))
183 { 187 {
184 anfds [fd].emask = want; 188 anfds [fd].emask = want;
185 189
190 /*
186 /* 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
187 /* 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 */
188 ev->events = (want & EV_READ ? EPOLLIN : 0) 199 ev->events = (want & EV_READ ? EPOLLIN : 0)
189 | (want & EV_WRITE ? EPOLLOUT : 0); 200 | (want & EV_WRITE ? EPOLLOUT : 0);
190 201
191 /* 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, */
192 /* which is fortunately easy to do for us. */ 203 /* which is fortunately easy to do for us. */
193 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))
194 { 205 {
195 postfork = 1; /* an error occurred, recreate kernel state */ 206 postfork |= 2; /* an error occurred, recreate kernel state */
196 continue; 207 continue;
197 } 208 }
198 } 209 }
199 210
200 fd_event (EV_A_ fd, got); 211 fd_event (EV_A_ fd, got);
215 unsigned char events = anfds [fd].events & (EV_READ | EV_WRITE); 226 unsigned char events = anfds [fd].events & (EV_READ | EV_WRITE);
216 227
217 if (anfds [fd].emask & EV_EMASK_EPERM && events) 228 if (anfds [fd].emask & EV_EMASK_EPERM && events)
218 fd_event (EV_A_ fd, events); 229 fd_event (EV_A_ fd, events);
219 else 230 else
231 {
220 epoll_eperms [i] = epoll_eperms [--epoll_epermcnt]; 232 epoll_eperms [i] = epoll_eperms [--epoll_epermcnt];
233 anfds [fd].emask = 0;
234 }
221 } 235 }
222} 236}
223 237
224int inline_size 238inline_size
239int
225epoll_init (EV_P_ int flags) 240epoll_init (EV_P_ int flags)
226{ 241{
227#ifdef EPOLL_CLOEXEC 242#if defined EPOLL_CLOEXEC && !defined __ANDROID__
228 backend_fd = epoll_create1 (EPOLL_CLOEXEC); 243 backend_fd = epoll_create1 (EPOLL_CLOEXEC);
229 244
230 if (backend_fd <= 0) 245 if (backend_fd < 0 && (errno == EINVAL || errno == ENOSYS))
231#endif 246#endif
232 backend_fd = epoll_create (256); 247 backend_fd = epoll_create (256);
233 248
234 if (backend_fd < 0) 249 if (backend_fd < 0)
235 return 0; 250 return 0;
236 251
237 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); 252 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
238 253
239 backend_fudge = 1./1024.; /* epoll does sometimes return early, this is just to avoid the worst */ 254 backend_mintime = 1e-3; /* epoll does sometimes return early, this is just to avoid the worst */
240 backend_modify = epoll_modify; 255 backend_modify = epoll_modify;
241 backend_poll = epoll_poll; 256 backend_poll = epoll_poll;
242 257
243 epoll_eventmax = 64; /* initial number of events receivable per poll */ 258 epoll_eventmax = 64; /* initial number of events receivable per poll */
244 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);
245 260
246 return EVBACKEND_EPOLL; 261 return EVBACKEND_EPOLL;
247} 262}
248 263
249void inline_size 264inline_size
265void
250epoll_destroy (EV_P) 266epoll_destroy (EV_P)
251{ 267{
252 ev_free (epoll_events); 268 ev_free (epoll_events);
253 array_free (epoll_eperm, EMPTY); 269 array_free (epoll_eperm, EMPTY);
254} 270}
255 271
256void inline_size 272inline_size
273void
257epoll_fork (EV_P) 274epoll_fork (EV_P)
258{ 275{
259 close (backend_fd); 276 close (backend_fd);
260 277
261 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