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 | * |
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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 | } |
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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 | |
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173 | /* |
173 | /* check for spurious notification */ |
174 | * check for spurious notification. |
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175 | * this only finds spurious notifications on egen updates |
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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 |
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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 | |
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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 |
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193 | * when we are no longer interested in them, but also when we get spurious |
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194 | * notifications for fds from another process. this is partially handled |
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195 | * above with the gencounter check (== our fd is not the event fd), and |
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196 | * partially here, when epoll_ctl returns an error (== a child has the fd |
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197 | * but we closed it). |
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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); |
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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 |
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231 | { |
220 | epoll_eperms [i] = epoll_eperms [--epoll_epermcnt]; |
232 | epoll_eperms [i] = epoll_eperms [--epoll_epermcnt]; |
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233 | anfds [fd].emask = 0; |
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234 | } |
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235 | } |
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236 | } |
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237 | |
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238 | static int |
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239 | epoll_epoll_create (void) |
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240 | { |
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241 | int fd; |
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242 | |
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243 | #if defined EPOLL_CLOEXEC && !defined __ANDROID__ |
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244 | fd = epoll_create1 (EPOLL_CLOEXEC); |
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245 | |
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246 | if (fd < 0 && (errno == EINVAL || errno == ENOSYS)) |
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247 | #endif |
221 | } |
248 | { |
222 | } |
249 | fd = epoll_create (256); |
223 | |
250 | |
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251 | if (fd >= 0) |
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252 | fcntl (fd, F_SETFD, FD_CLOEXEC); |
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253 | } |
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254 | |
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255 | return fd; |
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256 | } |
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257 | |
224 | int inline_size |
258 | inline_size |
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259 | int |
225 | epoll_init (EV_P_ int flags) |
260 | epoll_init (EV_P_ int flags) |
226 | { |
261 | { |
227 | #ifdef EPOLL_CLOEXEC |
262 | if ((backend_fd = epoll_epoll_create ()) < 0) |
228 | backend_fd = epoll_create1 (EPOLL_CLOEXEC); |
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229 | |
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230 | if (backend_fd <= 0) |
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231 | #endif |
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232 | backend_fd = epoll_create (256); |
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233 | |
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234 | if (backend_fd < 0) |
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235 | return 0; |
263 | return 0; |
236 | |
264 | |
237 | fcntl (backend_fd, F_SETFD, FD_CLOEXEC); |
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238 | |
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239 | backend_fudge = 1./1024.; /* epoll does sometimes return early, this is just to avoid the worst */ |
265 | backend_mintime = 1e-3; /* epoll does sometimes return early, this is just to avoid the worst */ |
240 | backend_modify = epoll_modify; |
266 | backend_modify = epoll_modify; |
241 | backend_poll = epoll_poll; |
267 | backend_poll = epoll_poll; |
242 | |
268 | |
243 | epoll_eventmax = 64; /* initial number of events receivable per poll */ |
269 | epoll_eventmax = 64; /* initial number of events receivable per poll */ |
244 | epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); |
270 | epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); |
245 | |
271 | |
246 | return EVBACKEND_EPOLL; |
272 | return EVBACKEND_EPOLL; |
247 | } |
273 | } |
248 | |
274 | |
249 | void inline_size |
275 | inline_size |
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276 | void |
250 | epoll_destroy (EV_P) |
277 | epoll_destroy (EV_P) |
251 | { |
278 | { |
252 | ev_free (epoll_events); |
279 | ev_free (epoll_events); |
253 | array_free (epoll_eperm, EMPTY); |
280 | array_free (epoll_eperm, EMPTY); |
254 | } |
281 | } |
255 | |
282 | |
256 | void inline_size |
283 | inline_size |
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284 | void |
257 | epoll_fork (EV_P) |
285 | epoll_fork (EV_P) |
258 | { |
286 | { |
259 | close (backend_fd); |
287 | close (backend_fd); |
260 | |
288 | |
261 | while ((backend_fd = epoll_create (256)) < 0) |
289 | while ((backend_fd = epoll_epoll_create ()) < 0) |
262 | ev_syserr ("(libev) epoll_create"); |
290 | ev_syserr ("(libev) epoll_create"); |
263 | |
291 | |
264 | fcntl (backend_fd, F_SETFD, FD_CLOEXEC); |
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265 | |
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266 | fd_rearm_all (EV_A); |
292 | fd_rearm_all (EV_A); |
267 | } |
293 | } |
268 | |
294 | |