… | |
… | |
182 | array_needsize (struct iocb *, linuxaio_submits, linuxaio_submitmax, linuxaio_submitcnt, array_needsize_noinit); |
182 | array_needsize (struct iocb *, linuxaio_submits, linuxaio_submitmax, linuxaio_submitcnt, array_needsize_noinit); |
183 | linuxaio_submits [linuxaio_submitcnt - 1] = &iocb->io; |
183 | linuxaio_submits [linuxaio_submitcnt - 1] = &iocb->io; |
184 | } |
184 | } |
185 | } |
185 | } |
186 | |
186 | |
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187 | #if EPOLL_FALLBACK |
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188 | |
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189 | static void |
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190 | linuxaio_rearm_epoll (EV_P_ struct iocb *iocb, int op) |
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191 | { |
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192 | struct epoll_event eev; |
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193 | |
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194 | eev.events = EPOLLONESHOT; |
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195 | if (iocb->aio_buf & POLLIN ) eev.events |= EPOLLIN ; |
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196 | if (iocb->aio_buf & POLLOUT) eev.events |= EPOLLOUT; |
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197 | eev.data.fd = iocb->aio_fildes; |
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198 | |
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199 | if (epoll_ctl (backend_fd, op, iocb->aio_fildes, &eev) < 0) |
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200 | ev_syserr ("(libeio) linuxaio epoll_ctl"); |
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201 | } |
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202 | |
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203 | static void |
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204 | linuxaio_epoll_cb (EV_P_ struct ev_io *w, int revents) |
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205 | { |
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206 | struct epoll_event events[16]; |
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207 | |
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208 | for (;;) |
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209 | { |
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210 | int idx; |
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211 | int res = epoll_wait (backend_fd, events, sizeof (events) / sizeof (events [0]), 0); |
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212 | |
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213 | if (expect_false (res < 0)) |
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214 | ev_syserr ("(libev) linuxaio epoll_wait"); |
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215 | else if (!res) |
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216 | break; |
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217 | |
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218 | for (idx = res; idx--; ) |
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219 | { |
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220 | int fd = events [idx].data.fd; |
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221 | uint32_t ev = events [idx].events; |
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222 | |
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223 | assert (("libev: iocb fd must be in-bounds", fd >= 0 && fd < anfdmax)); |
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224 | |
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225 | linuxaio_rearm_epoll (EV_A_ &linuxaio_iocbps [fd]->io, EPOLL_CTL_MOD); |
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226 | |
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227 | fd_event (EV_A_ fd, |
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228 | (ev & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0) |
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229 | | (ev & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0)); |
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230 | } |
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231 | |
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232 | if (res < sizeof (events) / sizeof (events [0])) |
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233 | break; |
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234 | } |
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235 | } |
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236 | |
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237 | #endif |
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238 | |
187 | static void |
239 | static void |
188 | linuxaio_parse_events (EV_P_ struct io_event *ev, int nr) |
240 | linuxaio_parse_events (EV_P_ struct io_event *ev, int nr) |
189 | { |
241 | { |
190 | while (nr) |
242 | while (nr) |
191 | { |
243 | { |
192 | int fd = ev->data; |
244 | int fd = ev->data; |
193 | int res = ev->res; |
245 | int res = ev->res; |
194 | |
246 | |
195 | assert (("libev: iocb fd must be in-bounds", fd >= 0 && fd < anfdmax)); |
247 | assert (("libev: iocb fd must be in-bounds", fd >= 0 && fd < anfdmax)); |
196 | |
248 | |
197 | /* linux aio is oneshot: rearm fd */ |
249 | /* linux aio is oneshot: rearm fd. TODO: this does more work than needed */ |
198 | linuxaio_iocbps [fd]->io.aio_buf = 0; |
250 | linuxaio_iocbps [fd]->io.aio_buf = 0; |
199 | anfds [fd].events = 0; |
251 | anfds [fd].events = 0; |
200 | fd_change (EV_A_ fd, 0); |
252 | fd_change (EV_A_ fd, 0); |
201 | |
253 | |
202 | /* feed events, we do not expect or handle POLLNVAL */ |
254 | /* feed events, we do not expect or handle POLLNVAL */ |
… | |
… | |
272 | |
324 | |
273 | /* no events, so wait for at least one, then poll ring buffer again */ |
325 | /* no events, so wait for at least one, then poll ring buffer again */ |
274 | /* this degrades to one event per loop iteration */ |
326 | /* this degrades to one event per loop iteration */ |
275 | /* if the ring buffer changes layout, but so be it */ |
327 | /* if the ring buffer changes layout, but so be it */ |
276 | |
328 | |
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329 | EV_RELEASE_CB; |
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330 | |
277 | ts.tv_sec = (long)timeout; |
331 | ts.tv_sec = (long)timeout; |
278 | ts.tv_nsec = (long)((timeout - ts.tv_sec) * 1e9); |
332 | ts.tv_nsec = (long)((timeout - ts.tv_sec) * 1e9); |
279 | |
333 | |
280 | res = ev_io_getevents (linuxaio_ctx, 1, sizeof (ioev) / sizeof (ioev [0]), ioev, &ts); |
334 | res = ev_io_getevents (linuxaio_ctx, 1, sizeof (ioev) / sizeof (ioev [0]), ioev, &ts); |
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335 | |
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336 | EV_ACQUIRE_CB; |
281 | |
337 | |
282 | if (res < 0) |
338 | if (res < 0) |
283 | if (errno == EINTR) |
339 | if (errno == EINTR) |
284 | /* ignored */; |
340 | /* ignored */; |
285 | else |
341 | else |
… | |
… | |
290 | linuxaio_parse_events (EV_A_ ioev, res); |
346 | linuxaio_parse_events (EV_A_ ioev, res); |
291 | linuxaio_get_events_from_ring (EV_A); |
347 | linuxaio_get_events_from_ring (EV_A); |
292 | } |
348 | } |
293 | } |
349 | } |
294 | |
350 | |
295 | #if EPOLL_FALLBACK |
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296 | static void |
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297 | linuxaio_rearm_epoll (EV_P_ struct iocb *iocb, int op) |
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298 | { |
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299 | struct epoll_event eev; |
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300 | |
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301 | eev.events = EPOLLONESHOT; |
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302 | if (iocb->aio_buf & POLLIN ) eev.events |= EPOLLIN ; |
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303 | if (iocb->aio_buf & POLLOUT) eev.events |= EPOLLOUT; |
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304 | eev.data.fd = iocb->aio_fildes; |
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305 | |
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306 | if (epoll_ctl (backend_fd, op, iocb->aio_fildes, &eev) < 0) |
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307 | ev_syserr ("(libeio) linuxaio epoll_ctl"); |
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308 | } |
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309 | #endif |
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310 | |
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311 | static void |
351 | static void |
312 | linuxaio_poll (EV_P_ ev_tstamp timeout) |
352 | linuxaio_poll (EV_P_ ev_tstamp timeout) |
313 | { |
353 | { |
314 | int submitted; |
354 | int submitted; |
315 | |
355 | |
… | |
… | |
318 | /* io_submit might return less than the requested number of iocbs */ |
358 | /* io_submit might return less than the requested number of iocbs */ |
319 | /* this is, afaics, only because of errors, but we go by the book and use a loop, */ |
359 | /* this is, afaics, only because of errors, but we go by the book and use a loop, */ |
320 | /* which allows us to pinpoint the errornous iocb */ |
360 | /* which allows us to pinpoint the errornous iocb */ |
321 | for (submitted = 0; submitted < linuxaio_submitcnt; ) |
361 | for (submitted = 0; submitted < linuxaio_submitcnt; ) |
322 | { |
362 | { |
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363 | #if 0 |
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364 | int res; |
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365 | if (linuxaio_submits[submitted]->aio_fildes == backend_fd) |
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366 | res = ev_io_submit (linuxaio_ctx, 1, linuxaio_submits + submitted); |
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367 | else |
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368 | { res = -1; errno = EINVAL; }; |
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369 | #else |
323 | int res = ev_io_submit (linuxaio_ctx, linuxaio_submitcnt - submitted, linuxaio_submits + submitted); |
370 | int res = ev_io_submit (linuxaio_ctx, linuxaio_submitcnt - submitted, linuxaio_submits + submitted); |
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371 | #endif |
324 | |
372 | |
325 | if (expect_false (res < 0)) |
373 | if (expect_false (res < 0)) |
326 | if (errno == EAGAIN) |
374 | if (errno == EAGAIN) |
327 | { |
375 | { |
328 | /* This happens when the ring buffer is full, at least. I assume this means |
376 | /* This happens when the ring buffer is full, at least. I assume this means |
329 | * that the event was queued synchronously during io_submit, and thus |
377 | * that the event was queued synchronously during io_submit, and thus |
330 | * the buffer overflowed. |
378 | * the buffer overflowed. |
331 | * In this case, we just try in next loop iteration. |
379 | * In this case, we just try in next loop iteration. |
332 | * This should not result in a few fds taking priority, as the interface |
380 | * This should not result in a few fds taking priority, as the interface |
333 | * is one-shot, and we submit iocb's in a round-robin fashion. |
381 | * is one-shot, and we submit iocb's in a round-robin fashion. |
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382 | * TODO: maybe make "submitted" persistent, so we don't have to memmove? |
334 | */ |
383 | */ |
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384 | if (ecb_expect_false (submitted)) |
|
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385 | { |
335 | memmove (linuxaio_submits, linuxaio_submits + submitted, (linuxaio_submitcnt - submitted) * sizeof (*linuxaio_submits)); |
386 | memmove (linuxaio_submits, linuxaio_submits + submitted, (linuxaio_submitcnt - submitted) * sizeof (*linuxaio_submits)); |
336 | linuxaio_submitcnt -= submitted; |
387 | linuxaio_submitcnt -= submitted; |
|
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388 | } |
|
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389 | |
337 | timeout = 0; |
390 | timeout = 0; |
338 | break; |
391 | break; |
339 | } |
392 | } |
340 | #if EPOLL_FALLBACK |
393 | #if EPOLL_FALLBACK |
341 | else if (errno == EINVAL) |
394 | else if (errno == EINVAL) |
342 | { |
395 | { |
343 | /* This happens for unsupported fds, officially, but in my testing, |
396 | /* This happens for unsupported fds, officially, but in my testing, |
344 | * also randomly happens for supported fds. We fall back to good old |
397 | * also randomly happens for supported fds. We fall back to good old |
345 | * poll() here, under the assumption that this is a very rare case. |
398 | * poll() here, under the assumption that this is a very rare case. |
346 | * See https://lore.kernel.org/patchwork/patch/1047453/ for evidence |
399 | * See https://lore.kernel.org/patchwork/patch/1047453/ to see |
347 | * that the problem is known, but ignored. |
400 | * discussion about such a case (ttys) where polling for POLLIN |
|
|
401 | * fails but POLLIN|POLLOUT works. |
348 | */ |
402 | */ |
349 | struct iocb *iocb = linuxaio_submits [submitted]; |
403 | struct iocb *iocb = linuxaio_submits [submitted]; |
350 | res = 1; /* skip this iocb */ |
404 | res = 1; /* skip this iocb */ |
351 | |
405 | |
352 | linuxaio_rearm_epoll (EV_A_ iocb, EPOLL_CTL_ADD); |
406 | linuxaio_rearm_epoll (EV_A_ iocb, EPOLL_CTL_ADD); |
… | |
… | |
363 | |
417 | |
364 | /* second phase: fetch and parse events */ |
418 | /* second phase: fetch and parse events */ |
365 | |
419 | |
366 | linuxaio_get_events (EV_A_ timeout); |
420 | linuxaio_get_events (EV_A_ timeout); |
367 | } |
421 | } |
368 | |
|
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369 | #if EPOLL_FALLBACK |
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370 | |
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371 | static void |
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372 | linuxaio_epoll_cb (EV_P_ struct ev_io *w, int revents) |
|
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373 | { |
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374 | struct epoll_event events[16]; |
|
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375 | |
|
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376 | for (;;) |
|
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377 | { |
|
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378 | int idx; |
|
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379 | int res = epoll_wait (backend_fd, events, sizeof (events) / sizeof (events [0]), 0); |
|
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380 | |
|
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381 | if (expect_false (res < 0)) |
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382 | ev_syserr ("(libev) linuxaio epoll_wait"); |
|
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383 | else if (!res) |
|
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384 | break; |
|
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385 | |
|
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386 | for (idx = res; idx--; ) |
|
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387 | { |
|
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388 | int fd = events [idx].data.fd; |
|
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389 | uint32_t ev = events [idx].events; |
|
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390 | |
|
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391 | assert (("libev: iocb fd must be in-bounds", fd >= 0 && fd < anfdmax)); |
|
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392 | |
|
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393 | linuxaio_rearm_epoll (EV_A_ &linuxaio_iocbps [fd]->io, EPOLL_CTL_MOD); |
|
|
394 | |
|
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395 | fd_event (EV_A_ fd, |
|
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396 | (ev & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0) |
|
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397 | | (ev & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0)); |
|
|
398 | } |
|
|
399 | |
|
|
400 | if (res < sizeof (events) / sizeof (events [0])) |
|
|
401 | break; |
|
|
402 | } |
|
|
403 | } |
|
|
404 | |
|
|
405 | #endif |
|
|
406 | |
422 | |
407 | inline_size |
423 | inline_size |
408 | int |
424 | int |
409 | linuxaio_init (EV_P_ int flags) |
425 | linuxaio_init (EV_P_ int flags) |
410 | { |
426 | { |
… | |
… | |
431 | ev_io_destroy (linuxaio_ctx); |
447 | ev_io_destroy (linuxaio_ctx); |
432 | return 0; |
448 | return 0; |
433 | } |
449 | } |
434 | |
450 | |
435 | ev_io_init (EV_A_ &linuxaio_epoll_w, linuxaio_epoll_cb, backend_fd, EV_READ); |
451 | ev_io_init (EV_A_ &linuxaio_epoll_w, linuxaio_epoll_cb, backend_fd, EV_READ); |
|
|
452 | ev_set_priority (&linuxaio_epoll_w, EV_MAXPRI); |
436 | ev_io_start (EV_A_ &linuxaio_epoll_w); |
453 | ev_io_start (EV_A_ &linuxaio_epoll_w); |
437 | ev_unref (EV_A); /* watcher should not keep loop alive */ |
454 | ev_unref (EV_A); /* watcher should not keep loop alive */ |
438 | #endif |
455 | #endif |
439 | |
456 | |
440 | backend_modify = linuxaio_modify; |
457 | backend_modify = linuxaio_modify; |