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Comparing libev/ev_epoll.c (file contents):
Revision 1.67 by root, Wed Jun 20 12:39:53 2012 UTC vs.
Revision 1.77 by root, Mon Jul 1 20:47:38 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 *
91 ev.data.u64 = (uint64_t)(uint32_t)fd 91 ev.data.u64 = (uint64_t)(uint32_t)fd
92 | ((uint64_t)(uint32_t)++anfds [fd].egen << 32); 92 | ((uint64_t)(uint32_t)++anfds [fd].egen << 32);
93 ev.events = (nev & EV_READ ? EPOLLIN : 0) 93 ev.events = (nev & EV_READ ? EPOLLIN : 0)
94 | (nev & EV_WRITE ? EPOLLOUT : 0); 94 | (nev & EV_WRITE ? EPOLLOUT : 0);
95 95
96 if (expect_true (!epoll_ctl (backend_fd, oev && oldmask != nev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &ev))) 96 if (ecb_expect_true (!epoll_ctl (backend_fd, oev && oldmask != nev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &ev)))
97 return; 97 return;
98 98
99 if (expect_true (errno == ENOENT)) 99 if (ecb_expect_true (errno == ENOENT))
100 { 100 {
101 /* if ENOENT then the fd went away, so try to do the right thing */ 101 /* if ENOENT then the fd went away, so try to do the right thing */
102 if (!nev) 102 if (!nev)
103 goto dec_egen; 103 goto dec_egen;
104 104
105 if (!epoll_ctl (backend_fd, EPOLL_CTL_ADD, fd, &ev)) 105 if (!epoll_ctl (backend_fd, EPOLL_CTL_ADD, fd, &ev))
106 return; 106 return;
107 } 107 }
108 else if (expect_true (errno == EEXIST)) 108 else if (ecb_expect_true (errno == EEXIST))
109 { 109 {
110 /* EEXIST means we ignored a previous DEL, but the fd is still active */ 110 /* EEXIST means we ignored a previous DEL, but the fd is still active */
111 /* if the kernel mask is the same as the new mask, we assume it hasn't changed */ 111 /* if the kernel mask is the same as the new mask, we assume it hasn't changed */
112 if (oldmask == nev) 112 if (oldmask == nev)
113 goto dec_egen; 113 goto dec_egen;
114 114
115 if (!epoll_ctl (backend_fd, EPOLL_CTL_MOD, fd, &ev)) 115 if (!epoll_ctl (backend_fd, EPOLL_CTL_MOD, fd, &ev))
116 return; 116 return;
117 } 117 }
118 else if (expect_true (errno == EPERM)) 118 else if (ecb_expect_true (errno == EPERM))
119 { 119 {
120 /* EPERM means the fd is always ready, but epoll is too snobbish */ 120 /* EPERM means the fd is always ready, but epoll is too snobbish */
121 /* to handle it, unlike select or poll. */ 121 /* to handle it, unlike select or poll. */
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 }
133 else
134 assert (("libev: I/O watcher with invalid fd found in epoll_ctl", errno != EBADF && errno != ELOOP && errno != EINVAL));
133 135
134 fd_kill (EV_A_ fd); 136 fd_kill (EV_A_ fd);
135 137
136dec_egen: 138dec_egen:
137 /* we didn't successfully call epoll_ctl, so decrement the generation counter again */ 139 /* we didn't successfully call epoll_ctl, so decrement the generation counter again */
142epoll_poll (EV_P_ ev_tstamp timeout) 144epoll_poll (EV_P_ ev_tstamp timeout)
143{ 145{
144 int i; 146 int i;
145 int eventcnt; 147 int eventcnt;
146 148
147 if (expect_false (epoll_epermcnt)) 149 if (ecb_expect_false (epoll_epermcnt))
148 timeout = 0.; 150 timeout = 0.;
149 151
150 /* epoll wait times cannot be larger than (LONG_MAX - 999UL) / HZ msecs, which is below */ 152 /* epoll wait times cannot be larger than (LONG_MAX - 999UL) / HZ msecs, which is below */
151 /* the default libev max wait time, however. */ 153 /* the default libev max wait time, however. */
152 EV_RELEASE_CB; 154 EV_RELEASE_CB;
153 eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, timeout * 1e3); 155 eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, timeout * 1e3);
154 EV_ACQUIRE_CB; 156 EV_ACQUIRE_CB;
155 157
156 if (expect_false (eventcnt < 0)) 158 if (ecb_expect_false (eventcnt < 0))
157 { 159 {
158 if (errno != EINTR) 160 if (errno != EINTR)
159 ev_syserr ("(libev) epoll_wait"); 161 ev_syserr ("(libev) epoll_wait");
160 162
161 return; 163 return;
174 * check for spurious notification. 176 * check for spurious notification.
175 * this only finds spurious notifications on egen updates 177 * this only finds spurious notifications on egen updates
176 * other spurious notifications will be found by epoll_ctl, below 178 * other spurious notifications will be found by epoll_ctl, below
177 * we assume that fd is always in range, as we never shrink the anfds array 179 * we assume that fd is always in range, as we never shrink the anfds array
178 */ 180 */
179 if (expect_false ((uint32_t)anfds [fd].egen != (uint32_t)(ev->data.u64 >> 32))) 181 if (ecb_expect_false ((uint32_t)anfds [fd].egen != (uint32_t)(ev->data.u64 >> 32)))
180 { 182 {
181 /* recreate kernel state */ 183 /* recreate kernel state */
182 postfork = 1; 184 postfork |= 2;
183 continue; 185 continue;
184 } 186 }
185 187
186 if (expect_false (got & ~want)) 188 if (ecb_expect_false (got & ~want))
187 { 189 {
188 anfds [fd].emask = want; 190 anfds [fd].emask = want;
189 191
190 /* 192 /*
191 * we received an event but are not interested in it, try mod or del 193 * we received an event but are not interested in it, try mod or del
201 203
202 /* pre-2.6.9 kernels require a non-null pointer with EPOLL_CTL_DEL, */ 204 /* pre-2.6.9 kernels require a non-null pointer with EPOLL_CTL_DEL, */
203 /* which is fortunately easy to do for us. */ 205 /* which is fortunately easy to do for us. */
204 if (epoll_ctl (backend_fd, want ? EPOLL_CTL_MOD : EPOLL_CTL_DEL, fd, ev)) 206 if (epoll_ctl (backend_fd, want ? EPOLL_CTL_MOD : EPOLL_CTL_DEL, fd, ev))
205 { 207 {
206 postfork = 1; /* an error occurred, recreate kernel state */ 208 postfork |= 2; /* an error occurred, recreate kernel state */
207 continue; 209 continue;
208 } 210 }
209 } 211 }
210 212
211 fd_event (EV_A_ fd, got); 213 fd_event (EV_A_ fd, got);
212 } 214 }
213 215
214 /* if the receive array was full, increase its size */ 216 /* if the receive array was full, increase its size */
215 if (expect_false (eventcnt == epoll_eventmax)) 217 if (ecb_expect_false (eventcnt == epoll_eventmax))
216 { 218 {
217 ev_free (epoll_events); 219 ev_free (epoll_events);
218 epoll_eventmax = array_nextsize (sizeof (struct epoll_event), epoll_eventmax, epoll_eventmax + 1); 220 epoll_eventmax = array_nextsize (sizeof (struct epoll_event), epoll_eventmax, epoll_eventmax + 1);
219 epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); 221 epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax);
220 } 222 }
226 unsigned char events = anfds [fd].events & (EV_READ | EV_WRITE); 228 unsigned char events = anfds [fd].events & (EV_READ | EV_WRITE);
227 229
228 if (anfds [fd].emask & EV_EMASK_EPERM && events) 230 if (anfds [fd].emask & EV_EMASK_EPERM && events)
229 fd_event (EV_A_ fd, events); 231 fd_event (EV_A_ fd, events);
230 else 232 else
233 {
231 epoll_eperms [i] = epoll_eperms [--epoll_epermcnt]; 234 epoll_eperms [i] = epoll_eperms [--epoll_epermcnt];
235 anfds [fd].emask = 0;
236 }
237 }
238}
239
240static int
241epoll_epoll_create (void)
242{
243 int fd;
244
245#if defined EPOLL_CLOEXEC && !defined __ANDROID__
246 fd = epoll_create1 (EPOLL_CLOEXEC);
247
248 if (fd < 0 && (errno == EINVAL || errno == ENOSYS))
249#endif
232 } 250 {
233} 251 fd = epoll_create (256);
234 252
253 if (fd >= 0)
254 fcntl (fd, F_SETFD, FD_CLOEXEC);
255 }
256
257 return fd;
258}
259
235int inline_size 260inline_size
261int
236epoll_init (EV_P_ int flags) 262epoll_init (EV_P_ int flags)
237{ 263{
238#ifdef EPOLL_CLOEXEC 264 if ((backend_fd = epoll_epoll_create ()) < 0)
239 backend_fd = epoll_create1 (EPOLL_CLOEXEC);
240
241 if (backend_fd < 0 && (errno == EINVAL || errno == ENOSYS))
242#endif
243 backend_fd = epoll_create (256);
244
245 if (backend_fd < 0)
246 return 0; 265 return 0;
247
248 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
249 266
250 backend_mintime = 1e-3; /* epoll does sometimes return early, this is just to avoid the worst */ 267 backend_mintime = 1e-3; /* epoll does sometimes return early, this is just to avoid the worst */
251 backend_modify = epoll_modify; 268 backend_modify = epoll_modify;
252 backend_poll = epoll_poll; 269 backend_poll = epoll_poll;
253 270
255 epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); 272 epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax);
256 273
257 return EVBACKEND_EPOLL; 274 return EVBACKEND_EPOLL;
258} 275}
259 276
260void inline_size 277inline_size
278void
261epoll_destroy (EV_P) 279epoll_destroy (EV_P)
262{ 280{
263 ev_free (epoll_events); 281 ev_free (epoll_events);
264 array_free (epoll_eperm, EMPTY); 282 array_free (epoll_eperm, EMPTY);
265} 283}
266 284
267void inline_size 285inline_size
286void
268epoll_fork (EV_P) 287epoll_fork (EV_P)
269{ 288{
270 close (backend_fd); 289 close (backend_fd);
271 290
272 while ((backend_fd = epoll_create (256)) < 0) 291 while ((backend_fd = epoll_epoll_create ()) < 0)
273 ev_syserr ("(libev) epoll_create"); 292 ev_syserr ("(libev) epoll_create");
274 293
275 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
276
277 fd_rearm_all (EV_A); 294 fd_rearm_all (EV_A);
278} 295}
279 296

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