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Comparing libev/ev_linuxaio.c (file contents):
Revision 1.7 by root, Sat Jun 22 16:25:53 2019 UTC vs.
Revision 1.24 by root, Mon Jun 24 22:27:29 2019 UTC

… …
35 * and other provisions required by the GPL. If you do not delete the 35 * and other provisions required by the GPL. If you do not delete the
36 * provisions above, a recipient may use your version of this file under 36 * provisions above, a recipient may use your version of this file under
37 * either the BSD or the GPL. 37 * either the BSD or the GPL.
38 */ 38 */
39 39
40#define EPOLL_FALLBACK 1
41
40#include <sys/time.h> /* actually linux/time.h, but we must assume they are compatible */ 42#include <sys/time.h> /* actually linux/time.h, but we must assume they are compatible */
41#include <poll.h> 43#include <poll.h>
42#include <linux/aio_abi.h> 44#include <linux/aio_abi.h>
43 45
46#if EPOLL_FALLBACK
47# include <sys/epoll.h>
48#endif
49
44/* we try to fill 4kB pages exactly. 50/* we try to fill 4kB pages exactly.
45 * the ring buffer header is 32 bytes, every io event is 32 bytes. 51 * the ring buffer header is 32 bytes, every io event is 32 bytes.
46 * the kernel takes the io event number, doubles it, adds 2, adds the ring buffer. 52 * the kernel takes the io event number, doubles it, adds 2, adds the ring buffer.
47 * therefore the calculation below will use "exactly" 8kB for the ring buffer 53 * therefore the calculation below will use "exactly" 4kB for the ring buffer
48 */ 54 */
49#define EV_LINUXAIO_DEPTH (256 / 2 - 2 - 1) /* max. number of io events per batch */ 55#define EV_LINUXAIO_DEPTH (128 / 2 - 2 - 1) /* max. number of io events per batch */
50 56
51/*****************************************************************************/ 57/*****************************************************************************/
52/* syscall wrapdadoop */ 58/* syscall wrapdadoop - this section has the raw syscall definitions */
53 59
54#include <sys/syscall.h> /* no glibc wrappers */ 60#include <sys/syscall.h> /* no glibc wrappers */
55 61
56/* aio_abi.h is not versioned in any way, so we cannot test for its existance */ 62/* aio_abi.h is not versioned in any way, so we cannot test for its existance */
57#define IOCB_CMD_POLL 5 63#define IOCB_CMD_POLL 5
… …
74 struct io_event io_events[0]; 80 struct io_event io_events[0];
75}; 81};
76 82
77inline_size 83inline_size
78int 84int
79ev_io_setup (unsigned nr_events, aio_context_t *ctx_idp) 85evsys_io_setup (unsigned nr_events, aio_context_t *ctx_idp)
80{ 86{
81 return syscall (SYS_io_setup, nr_events, ctx_idp); 87 return syscall (SYS_io_setup, nr_events, ctx_idp);
82} 88}
83 89
84inline_size 90inline_size
85int 91int
86ev_io_destroy (aio_context_t ctx_id) 92evsys_io_destroy (aio_context_t ctx_id)
87{ 93{
88 return syscall (SYS_io_destroy, ctx_id); 94 return syscall (SYS_io_destroy, ctx_id);
89} 95}
90 96
91inline_size 97inline_size
92int 98int
93ev_io_submit (aio_context_t ctx_id, long nr, struct iocb *cbp[]) 99evsys_io_submit (aio_context_t ctx_id, long nr, struct iocb *cbp[])
94{ 100{
95 return syscall (SYS_io_submit, ctx_id, nr, cbp); 101 return syscall (SYS_io_submit, ctx_id, nr, cbp);
96} 102}
97 103
98inline_size 104inline_size
99int 105int
100ev_io_cancel (aio_context_t ctx_id, struct iocb *cbp, struct io_event *result) 106evsys_io_cancel (aio_context_t ctx_id, struct iocb *cbp, struct io_event *result)
101{ 107{
102 return syscall (SYS_io_cancel, ctx_id, cbp, result); 108 return syscall (SYS_io_cancel, ctx_id, cbp, result);
103} 109}
104 110
105inline_size 111inline_size
106int 112int
107ev_io_getevents (aio_context_t ctx_id, long min_nr, long nr, struct io_event *events, struct timespec *timeout) 113evsys_io_getevents (aio_context_t ctx_id, long min_nr, long nr, struct io_event *events, struct timespec *timeout)
108{ 114{
109 return syscall (SYS_io_getevents, ctx_id, min_nr, nr, events, timeout); 115 return syscall (SYS_io_getevents, ctx_id, min_nr, nr, events, timeout);
110} 116}
111 117
112/*****************************************************************************/ 118/*****************************************************************************/
… …
119 /*int inuse;*/ 125 /*int inuse;*/
120} *ANIOCBP; 126} *ANIOCBP;
121 127
122inline_size 128inline_size
123void 129void
124linuxaio_array_needsize_iocbp (ANIOCBP *base, int count) 130linuxaio_array_needsize_iocbp (ANIOCBP *base, int offset, int count)
125{ 131{
126 /* TODO: quite the overhead to allocate every iocb separately, maybe use our own alocator? */
127 while (count--) 132 while (count--)
128 { 133 {
134 /* TODO: quite the overhead to allocate every iocb separately, maybe use our own alocator? */
129 *base = (ANIOCBP)ev_malloc (sizeof (**base)); 135 ANIOCBP iocb = (ANIOCBP)ev_malloc (sizeof (*iocb));
130 /* TODO: full zero initialize required? */ 136
137 /* full zero initialise is probably not required at the moment, but
138 * this is not well documented, so we better do it.
139 */
131 memset (*base, 0, sizeof (**base)); 140 memset (iocb, 0, sizeof (*iocb));
132 /* would be nice to initialize fd/data as well, but array_needsize API doesn't support that */ 141
133 (*base)->io.aio_lio_opcode = IOCB_CMD_POLL; 142 iocb->io.aio_lio_opcode = IOCB_CMD_POLL;
134 ++base; 143 iocb->io.aio_data = offset;
144 iocb->io.aio_fildes = offset;
145
146 base [offset++] = iocb;
135 } 147 }
136} 148}
137 149
138ecb_cold 150ecb_cold
139static void 151static void
… …
147 159
148static void 160static void
149linuxaio_modify (EV_P_ int fd, int oev, int nev) 161linuxaio_modify (EV_P_ int fd, int oev, int nev)
150{ 162{
151 array_needsize (ANIOCBP, linuxaio_iocbps, linuxaio_iocbpmax, fd + 1, linuxaio_array_needsize_iocbp); 163 array_needsize (ANIOCBP, linuxaio_iocbps, linuxaio_iocbpmax, fd + 1, linuxaio_array_needsize_iocbp);
152 struct aniocb *iocb = linuxaio_iocbps [fd]; 164 ANIOCBP iocb = linuxaio_iocbps [fd];
165
166#if EPOLL_FALLBACK
167 if (iocb->io.aio_reqprio < 0)
168 {
169 epoll_ctl (backend_fd, EPOLL_CTL_DEL, fd, 0);
170 iocb->io.aio_reqprio = 0;
171 }
172#endif
153 173
154 if (iocb->io.aio_buf) 174 if (iocb->io.aio_buf)
155 ev_io_cancel (linuxaio_ctx, &iocb->io, (struct io_event *)0); /* always returns an error relevant kernels */ 175 evsys_io_cancel (linuxaio_ctx, &iocb->io, (struct io_event *)0); /* always returns an error relevant kernels */
156 176
157 if (nev) 177 if (nev)
158 { 178 {
159 iocb->io.aio_data = fd;
160 iocb->io.aio_fildes = fd;
161 iocb->io.aio_buf = 179 iocb->io.aio_buf =
162 (nev & EV_READ ? POLLIN : 0) 180 (nev & EV_READ ? POLLIN : 0)
163 | (nev & EV_WRITE ? POLLOUT : 0); 181 | (nev & EV_WRITE ? POLLOUT : 0);
164 182
165 /* queue iocb up for io_submit */ 183 /* queue iocb up for io_submit */
166 /* this assumes we only ever get one call per fd per loop iteration */ 184 /* this assumes we only ever get one call per fd per loop iteration */
… …
168 array_needsize (struct iocb *, linuxaio_submits, linuxaio_submitmax, linuxaio_submitcnt, array_needsize_noinit); 186 array_needsize (struct iocb *, linuxaio_submits, linuxaio_submitmax, linuxaio_submitcnt, array_needsize_noinit);
169 linuxaio_submits [linuxaio_submitcnt - 1] = &iocb->io; 187 linuxaio_submits [linuxaio_submitcnt - 1] = &iocb->io;
170 } 188 }
171} 189}
172 190
191#if EPOLL_FALLBACK
192
193static void
194linuxaio_rearm_epoll (EV_P_ struct iocb *iocb, int op)
195{
196 struct epoll_event eev;
197
198 eev.events = EPOLLONESHOT;
199 if (iocb->aio_buf & POLLIN ) eev.events |= EPOLLIN ;
200 if (iocb->aio_buf & POLLOUT) eev.events |= EPOLLOUT;
201 eev.data.fd = iocb->aio_fildes;
202
203 if (epoll_ctl (backend_fd, op, iocb->aio_fildes, &eev) < 0)
204 ev_syserr ("(libeio) linuxaio epoll_ctl");
205}
206
207static void
208linuxaio_epoll_cb (EV_P_ struct ev_io *w, int revents)
209{
210 struct epoll_event events[16];
211
212 for (;;)
213 {
214 int idx;
215 int res = epoll_wait (backend_fd, events, sizeof (events) / sizeof (events [0]), 0);
216
217 if (expect_false (res < 0))
218 ev_syserr ("(libev) linuxaio epoll_wait");
219 else if (!res)
220 break;
221
222 for (idx = res; idx--; )
223 {
224 int fd = events [idx].data.fd;
225 uint32_t ev = events [idx].events;
226
227 assert (("libev: iocb fd must be in-bounds", fd >= 0 && fd < anfdmax));
228
229 linuxaio_rearm_epoll (EV_A_ &linuxaio_iocbps [fd]->io, EPOLL_CTL_MOD);
230
231 fd_event (EV_A_ fd,
232 (ev & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0)
233 | (ev & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0));
234 }
235
236 if (res < sizeof (events) / sizeof (events [0]))
237 break;
238 }
239}
240
241#endif
242
173static void 243static void
174linuxaio_parse_events (EV_P_ struct io_event *ev, int nr) 244linuxaio_parse_events (EV_P_ struct io_event *ev, int nr)
175{ 245{
176 while (nr) 246 while (nr)
177 { 247 {
178 int fd = ev->data; 248 int fd = ev->data;
179 int res = ev->res; 249 int res = ev->res;
180 250
181 assert (("libev: iocb fd must be in-bounds", fd >= 0 && fd < anfdmax)); 251 assert (("libev: iocb fd must be in-bounds", fd >= 0 && fd < anfdmax));
182 252
183 /* linux aio is oneshot: rearm fd */ 253 /* linux aio is oneshot: rearm fd. TODO: this does more work than needed */
184 linuxaio_iocbps [fd]->io.aio_buf = 0; 254 linuxaio_iocbps [fd]->io.aio_buf = 0;
185 anfds [fd].events = 0; 255 anfds [fd].events = 0;
186 fd_change (EV_A_ fd, 0); 256 fd_change (EV_A_ fd, 0);
187 257
188 /* feed events, we do not expect or handle POLLNVAL */ 258 /* feed events, we do not expect or handle POLLNVAL */
189 if (ecb_expect_false (res & POLLNVAL))
190 fd_kill (EV_A_ fd);
191 else
192 fd_event ( 259 fd_event (
193 EV_A_ 260 EV_A_
194 fd, 261 fd,
195 (res & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0) 262 (res & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
196 | (res & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0) 263 | (res & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
197 ); 264 );
198 265
199 --nr; 266 --nr;
200 ++ev; 267 ++ev;
201 } 268 }
202} 269}
… …
205static int 272static int
206linuxaio_get_events_from_ring (EV_P) 273linuxaio_get_events_from_ring (EV_P)
207{ 274{
208 struct aio_ring *ring = (struct aio_ring *)linuxaio_ctx; 275 struct aio_ring *ring = (struct aio_ring *)linuxaio_ctx;
209 276
210 ECB_MEMORY_FENCE_ACQUIRE; 277 /* the kernel reads and writes both of these variables, */
211 278 /* as a C extension, we assume that volatile use here */
212 unsigned head = ring->head; 279 /* both makes reads atomic and once-only */
280 unsigned head = *(volatile unsigned *)&ring->head;
213 unsigned tail = *(volatile unsigned *)&ring->tail; 281 unsigned tail = *(volatile unsigned *)&ring->tail;
214 282
215 if (head == tail) 283 if (head == tail)
216 return 0; 284 return 0;
217 285
218 /* bail out if the ring buffer doesn't match the expected layout */ 286 /* bail out if the ring buffer doesn't match the expected layout */
219 if (ecb_expect_false (ring->magic != AIO_RING_MAGIC) 287 if (expect_false (ring->magic != AIO_RING_MAGIC)
220 || ring->incompat_features != AIO_RING_INCOMPAT_FEATURES 288 || ring->incompat_features != AIO_RING_INCOMPAT_FEATURES
221 || ring->header_length != sizeof (struct aio_ring)) /* TODO: or use it to find io_event[0]? */ 289 || ring->header_length != sizeof (struct aio_ring)) /* TODO: or use it to find io_event[0]? */
222 return 0; 290 return 0;
291
292 /* make sure the events up to tail are visible */
293 ECB_MEMORY_FENCE_ACQUIRE;
223 294
224 /* parse all available events, but only once, to avoid starvation */ 295 /* parse all available events, but only once, to avoid starvation */
225 if (tail > head) /* normal case around */ 296 if (tail > head) /* normal case around */
226 linuxaio_parse_events (EV_A_ ring->io_events + head, tail - head); 297 linuxaio_parse_events (EV_A_ ring->io_events + head, tail - head);
227 else /* wrapped around */ 298 else /* wrapped around */
228 { 299 {
229 linuxaio_parse_events (EV_A_ ring->io_events + head, ring->nr - head); 300 linuxaio_parse_events (EV_A_ ring->io_events + head, ring->nr - head);
230 linuxaio_parse_events (EV_A_ ring->io_events, tail); 301 linuxaio_parse_events (EV_A_ ring->io_events, tail);
231 } 302 }
232 303
233 ring->head = tail; 304 ECB_MEMORY_FENCE_RELAXED;
305 /* as an extension to C, we hope that the volatile will make this atomic and once-only */
306 *(volatile unsigned *)&ring->head = tail;
307 /* make sure kernel can see our new head value - probably not required */
308 ECB_MEMORY_FENCE_RELEASE;
234 309
235 return 1; 310 return 1;
236} 311}
237 312
238/* read at least one event from kernel, or timeout */ 313/* read at least one event from kernel, or timeout */
239inline_size 314inline_size
240void 315void
241linuxaio_get_events (EV_P_ ev_tstamp timeout) 316linuxaio_get_events (EV_P_ ev_tstamp timeout)
242{ 317{
243 struct timespec ts; 318 struct timespec ts;
244 struct io_event ioev; 319 struct io_event ioev[1];
245 int res; 320 int res;
246 321
247 if (linuxaio_get_events_from_ring (EV_A)) 322 if (linuxaio_get_events_from_ring (EV_A))
248 return; 323 return;
249 324
250 /* 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 */
251 /* this degrades to one event per loop iteration */ 326 /* this degrades to one event per loop iteration */
252 /* if the ring buffer changes layout, but so be it */ 327 /* if the ring buffer changes layout, but so be it */
253 328
329 EV_RELEASE_CB;
330
254 ts.tv_sec = (long)timeout; 331 ts.tv_sec = (long)timeout;
255 ts.tv_nsec = (long)((timeout - ts.tv_sec) * 1e9); 332 ts.tv_nsec = (long)((timeout - ts.tv_sec) * 1e9);
256 333
257 res = ev_io_getevents (linuxaio_ctx, 1, 1, &ioev, &ts); 334 res = evsys_io_getevents (linuxaio_ctx, 1, sizeof (ioev) / sizeof (ioev [0]), ioev, &ts);
335
336 EV_ACQUIRE_CB;
258 337
259 if (res < 0) 338 if (res < 0)
339 if (errno == EINTR)
340 /* ignored */;
341 else
260 ev_syserr ("(libev) io_getevents"); 342 ev_syserr ("(libev) linuxaio io_getevents");
261 else if (res) 343 else if (res)
262 { 344 {
263 /* at least one event received, handle it and any remaining ones in the ring buffer */ 345 /* at least one event received, handle it and any remaining ones in the ring buffer */
264 linuxaio_parse_events (EV_A_ &ioev, 1); 346 linuxaio_parse_events (EV_A_ ioev, res);
265 linuxaio_get_events_from_ring (EV_A); 347 linuxaio_get_events_from_ring (EV_A);
266 } 348 }
267} 349}
268 350
269static void 351static void
… …
276 /* io_submit might return less than the requested number of iocbs */ 358 /* io_submit might return less than the requested number of iocbs */
277 /* 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, */
278 /* which allows us to pinpoint the errornous iocb */ 360 /* which allows us to pinpoint the errornous iocb */
279 for (submitted = 0; submitted < linuxaio_submitcnt; ) 361 for (submitted = 0; submitted < linuxaio_submitcnt; )
280 { 362 {
363#if 0
364 int res;
365 if (linuxaio_submits[submitted]->aio_fildes == backend_fd)
366 res = evsys_io_submit (linuxaio_ctx, 1, linuxaio_submits + submitted);
367 else
368 { res = -1; errno = EINVAL; };
369#else
281 int res = ev_io_submit (linuxaio_ctx, linuxaio_submitcnt - submitted, linuxaio_submits + submitted); 370 int res = evsys_io_submit (linuxaio_ctx, linuxaio_submitcnt - submitted, linuxaio_submits + submitted);
371#endif
282 372
283 if (ecb_expect_false (res < 0)) 373 if (expect_false (res < 0))
284 if (errno == EAGAIN) 374 if (errno == EAGAIN)
285 { 375 {
286 /* 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
287 * that the event was queued synchronously during io_submit, and thus 377 * that the event was queued synchronously during io_submit, and thus
288 * the buffer overflowd. 378 * the buffer overflowed.
289 * In this case, we just try next loop iteration. 379 * In this case, we just try in next loop iteration.
290 * 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
291 * 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.
382 * TODO: maybe make "submitted" persistent, so we don't have to memmove?
292 */ 383 */
384 if (ecb_expect_false (submitted))
385 {
293 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));
294 linuxaio_submitcnt -= submitted; 387 linuxaio_submitcnt -= submitted;
388 }
389
295 timeout = 0; 390 timeout = 0;
296 break; 391 break;
297 } 392 }
393#if EPOLL_FALLBACK
394 else if (errno == EINVAL)
395 {
396 /* This happens for unsupported fds, officially, but in my testing,
397 * also randomly happens for supported fds. We fall back to good old
398 * poll() here, under the assumption that this is a very rare case.
399 * See https://lore.kernel.org/patchwork/patch/1047453/ to see
400 * discussion about such a case (ttys) where polling for POLLIN
401 * fails but POLLIN|POLLOUT works.
402 */
403 struct iocb *iocb = linuxaio_submits [submitted];
404
405 linuxaio_rearm_epoll (EV_A_ linuxaio_submits [submitted], EPOLL_CTL_ADD);
406 iocb->aio_reqprio = -1; /* mark iocb as epoll */
407
408 res = 1; /* skip this iocb */
409 }
410#endif
411 else if (errno == EBADF)
412 {
413 fd_kill (EV_A_ linuxaio_submits [submitted]->aio_fildes);
414
415 res = 1; /* skip this iocb */
416 }
298 else 417 else
299 ev_syserr ("(libev) io_submit"); 418 ev_syserr ("(libev) linuxaio io_submit");
300 419
301 submitted += res; 420 submitted += res;
302 } 421 }
303 422
304 linuxaio_submitcnt = 0; 423 linuxaio_submitcnt = 0;
… …
312int 431int
313linuxaio_init (EV_P_ int flags) 432linuxaio_init (EV_P_ int flags)
314{ 433{
315 /* would be great to have a nice test for IOCB_CMD_POLL instead */ 434 /* would be great to have a nice test for IOCB_CMD_POLL instead */
316 /* also: test some semi-common fd types, such as files and ttys in recommended_backends */ 435 /* also: test some semi-common fd types, such as files and ttys in recommended_backends */
317 if (ev_linux_version () < 0x041200) /* 4.18 introduced IOCB_CMD_POLL */ 436#if EPOLL_FALLBACK
437 /* 4.19 made epoll work */
438 if (ev_linux_version () < 0x041300)
318 return 0; 439 return 0;
440#else
441 /* 4.18 introduced IOCB_CMD_POLL */
442 if (ev_linux_version () < 0x041200)
443 return 0;
444#endif
319 445
320 linuxaio_ctx = 0; 446 linuxaio_ctx = 0;
321 if (ev_io_setup (EV_LINUXAIO_DEPTH, &linuxaio_ctx) < 0) 447 if (evsys_io_setup (EV_LINUXAIO_DEPTH, &linuxaio_ctx) < 0)
322 return 0; 448 return 0;
449
450#if EPOLL_FALLBACK
451 backend_fd = ev_epoll_create ();
452 if (backend_fd < 0)
453 {
454 evsys_io_destroy (linuxaio_ctx);
455 return 0;
456 }
457
458 ev_io_init (EV_A_ &linuxaio_epoll_w, linuxaio_epoll_cb, backend_fd, EV_READ);
459 ev_set_priority (&linuxaio_epoll_w, EV_MAXPRI);
460 ev_io_start (EV_A_ &linuxaio_epoll_w);
461 ev_unref (EV_A); /* watcher should not keep loop alive */
462#endif
323 463
324 backend_modify = linuxaio_modify; 464 backend_modify = linuxaio_modify;
325 backend_poll = linuxaio_poll; 465 backend_poll = linuxaio_poll;
326 466
327 linuxaio_iocbpmax = 0; 467 linuxaio_iocbpmax = 0;
… …
336 476
337inline_size 477inline_size
338void 478void
339linuxaio_destroy (EV_P) 479linuxaio_destroy (EV_P)
340{ 480{
481#if EPOLL_FALLBACK
482 close (backend_fd);
483#endif
341 linuxaio_free_iocbp (EV_A); 484 linuxaio_free_iocbp (EV_A);
342 ev_io_destroy (linuxaio_ctx); 485 evsys_io_destroy (linuxaio_ctx);
343} 486}
344 487
345inline_size 488inline_size
346void 489void
347linuxaio_fork (EV_P) 490linuxaio_fork (EV_P)
… …
349 /* this frees all iocbs, which is very heavy-handed */ 492 /* this frees all iocbs, which is very heavy-handed */
350 linuxaio_destroy (EV_A); 493 linuxaio_destroy (EV_A);
351 linuxaio_submitcnt = 0; /* all pointers were invalidated */ 494 linuxaio_submitcnt = 0; /* all pointers were invalidated */
352 495
353 linuxaio_ctx = 0; 496 linuxaio_ctx = 0;
354 while (ev_io_setup (EV_LINUXAIO_DEPTH, &linuxaio_ctx) < 0) 497 while (evsys_io_setup (EV_LINUXAIO_DEPTH, &linuxaio_ctx) < 0)
355 ev_syserr ("(libev) io_setup"); 498 ev_syserr ("(libev) linuxaio io_setup");
499
500#if EPOLL_FALLBACK
501 while ((backend_fd = ev_epoll_create ()) < 0)
502 ev_syserr ("(libev) linuxaio epoll_create");
503
504 ev_io_stop (EV_A_ &linuxaio_epoll_w);
505 ev_io_init (EV_A_ &linuxaio_epoll_w, linuxaio_epoll_cb, backend_fd, EV_READ);
506 ev_io_start (EV_A_ &linuxaio_epoll_w);
507#endif
356 508
357 fd_rearm_all (EV_A); 509 fd_rearm_all (EV_A);
358} 510}
359 511

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