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Comparing libev/ev_linuxaio.c (file contents):
Revision 1.47 by root, Mon Jul 8 02:45:43 2019 UTC vs.
Revision 1.54 by sf-exg, Sun May 14 19:02:31 2023 UTC

… …
91/*****************************************************************************/ 91/*****************************************************************************/
92/* syscall wrapdadoop - this section has the raw api/abi definitions */ 92/* syscall wrapdadoop - this section has the raw api/abi definitions */
93 93
94#include <sys/syscall.h> /* no glibc wrappers */ 94#include <sys/syscall.h> /* no glibc wrappers */
95 95
96/* aio_abi.h is not versioned in any way, so we cannot test for its existance */ 96/* aio_abi.h is not versioned in any way, so we cannot test for its existence */
97#define IOCB_CMD_POLL 5 97#define IOCB_CMD_POLL 5
98 98
99/* taken from linux/fs/aio.c. yup, that's a .c file. 99/* taken from linux/fs/aio.c. yup, that's a .c file.
100 * not only is this totally undocumented, not even the source code 100 * not only is this totally undocumented, not even the source code
101 * can tell you what the future semantics of compat_features and 101 * can tell you what the future semantics of compat_features and
… …
212 * this is not well documented, so we better do it. 212 * this is not well documented, so we better do it.
213 */ 213 */
214 memset (iocb, 0, sizeof (*iocb)); 214 memset (iocb, 0, sizeof (*iocb));
215 215
216 iocb->io.aio_lio_opcode = IOCB_CMD_POLL; 216 iocb->io.aio_lio_opcode = IOCB_CMD_POLL;
217 iocb->io.aio_data = offset;
218 iocb->io.aio_fildes = offset; 217 iocb->io.aio_fildes = offset;
219 218
220 base [offset++] = iocb; 219 base [offset++] = iocb;
221 } 220 }
222} 221}
… …
234static void 233static void
235linuxaio_modify (EV_P_ int fd, int oev, int nev) 234linuxaio_modify (EV_P_ int fd, int oev, int nev)
236{ 235{
237 array_needsize (ANIOCBP, linuxaio_iocbps, linuxaio_iocbpmax, fd + 1, linuxaio_array_needsize_iocbp); 236 array_needsize (ANIOCBP, linuxaio_iocbps, linuxaio_iocbpmax, fd + 1, linuxaio_array_needsize_iocbp);
238 ANIOCBP iocb = linuxaio_iocbps [fd]; 237 ANIOCBP iocb = linuxaio_iocbps [fd];
238 ANFD *anfd = &anfds [fd];
239 239
240 if (ecb_expect_false (iocb->io.aio_reqprio < 0)) 240 if (ecb_expect_false (iocb->io.aio_reqprio < 0))
241 { 241 {
242 /* we handed this fd over to epoll, so undo this first */ 242 /* we handed this fd over to epoll, so undo this first */
243 /* we do it manually because the optimisations on epoll_modify won't do us any good */ 243 /* we do it manually because the optimisations on epoll_modify won't do us any good */
244 epoll_ctl (backend_fd, EPOLL_CTL_DEL, fd, 0); 244 epoll_ctl (backend_fd, EPOLL_CTL_DEL, fd, 0);
245 anfds [fd].emask = 0; 245 anfd->emask = 0;
246 iocb->io.aio_reqprio = 0; 246 iocb->io.aio_reqprio = 0;
247 } 247 }
248 else if (ecb_expect_false (iocb->io.aio_buf)) 248 else if (ecb_expect_false (iocb->io.aio_buf))
249 { 249 {
250 /* iocb active, so cancel it first before resubmit */ 250 /* iocb active, so cancel it first before resubmit */
251 /* this assumes we only ever get one call per fd per loop iteration */
251 for (;;) 252 for (;;)
252 { 253 {
253 /* on all relevant kernels, io_cancel fails with EINPROGRESS on "success" */ 254 /* on all relevant kernels, io_cancel fails with EINPROGRESS on "success" */
254 if (ecb_expect_false (evsys_io_cancel (linuxaio_ctx, &iocb->io, (struct io_event *)0) == 0)) 255 if (ecb_expect_false (evsys_io_cancel (linuxaio_ctx, &iocb->io, (struct io_event *)0) == 0))
255 break; 256 break;
… …
262 { 263 {
263 assert (("libev: linuxaio unexpected io_cancel failed", errno != EINTR && errno != EINPROGRESS)); 264 assert (("libev: linuxaio unexpected io_cancel failed", errno != EINTR && errno != EINPROGRESS));
264 break; 265 break;
265 } 266 }
266 } 267 }
267 }
268 268
269 iocb->io.aio_buf = 269 /* increment generation counter to avoid handling old events */
270 (nev & EV_READ ? POLLIN : 0) 270 ++anfd->egen;
271 }
272
273 iocb->io.aio_buf = (nev & EV_READ ? POLLIN : 0)
271 | (nev & EV_WRITE ? POLLOUT : 0); 274 | (nev & EV_WRITE ? POLLOUT : 0);
272 275
273 if (nev) 276 if (nev)
274 { 277 {
278 iocb->io.aio_data = (uint32_t)fd | ((__u64)(uint32_t)anfd->egen << 32);
279
275 /* queue iocb up for io_submit */ 280 /* queue iocb up for io_submit */
276 /* this assumes we only ever get one call per fd per loop iteration */ 281 /* this assumes we only ever get one call per fd per loop iteration */
277 ++linuxaio_submitcnt; 282 ++linuxaio_submitcnt;
278 array_needsize (struct iocb *, linuxaio_submits, linuxaio_submitmax, linuxaio_submitcnt, array_needsize_noinit); 283 array_needsize (struct iocb *, linuxaio_submits, linuxaio_submitmax, linuxaio_submitcnt, array_needsize_noinit);
279 linuxaio_submits [linuxaio_submitcnt - 1] = &iocb->io; 284 linuxaio_submits [linuxaio_submitcnt - 1] = &iocb->io;
… …
298static void 303static void
299linuxaio_parse_events (EV_P_ struct io_event *ev, int nr) 304linuxaio_parse_events (EV_P_ struct io_event *ev, int nr)
300{ 305{
301 while (nr) 306 while (nr)
302 { 307 {
303 int fd = ev->data; 308 int fd = ev->data & 0xffffffff;
309 uint32_t gen = ev->data >> 32;
304 int res = ev->res; 310 int res = ev->res;
305 311
306 assert (("libev: iocb fd must be in-bounds", fd >= 0 && fd < anfdmax)); 312 assert (("libev: iocb fd must be in-bounds", fd >= 0 && fd < anfdmax));
307 313
314 /* only accept events if generation counter matches */
315 if (ecb_expect_true (gen == (uint32_t)anfds [fd].egen))
316 {
308 /* feed events, we do not expect or handle POLLNVAL */ 317 /* feed events, we do not expect or handle POLLNVAL */
309 fd_event ( 318 fd_event (
310 EV_A_ 319 EV_A_
311 fd, 320 fd,
312 (res & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0) 321 (res & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
313 | (res & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0) 322 | (res & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
314 ); 323 );
315 324
316 /* linux aio is oneshot: rearm fd. TODO: this does more work than strictly needed */ 325 /* linux aio is oneshot: rearm fd. TODO: this does more work than strictly needed */
317 linuxaio_fd_rearm (EV_A_ fd); 326 linuxaio_fd_rearm (EV_A_ fd);
327 }
318 328
319 --nr; 329 --nr;
320 ++ev; 330 ++ev;
321 } 331 }
322} 332}
… …
426 break; 436 break;
427 } 437 }
428 else 438 else
429 break; /* no events from the kernel, we are done */ 439 break; /* no events from the kernel, we are done */
430 440
431 timeout = 0; /* only wait in the first iteration */ 441 timeout = EV_TS_CONST (0.); /* only wait in the first iteration */
432 } 442 }
433} 443}
434 444
435inline_size 445inline_size
436int 446int
… …
506 backend = EVBACKEND_EPOLL; 516 backend = EVBACKEND_EPOLL;
507 backend_modify = epoll_modify; 517 backend_modify = epoll_modify;
508 backend_poll = epoll_poll; 518 backend_poll = epoll_poll;
509 } 519 }
510 520
511 timeout = 0; 521 timeout = EV_TS_CONST (0.);
512 /* it's easiest to handle this mess in another iteration */ 522 /* it's easiest to handle this mess in another iteration */
513 return; 523 return;
514 } 524 }
515 else if (errno == EBADF) 525 else if (errno == EBADF)
516 { 526 {
… …
556 { 566 {
557 epoll_destroy (EV_A); 567 epoll_destroy (EV_A);
558 return 0; 568 return 0;
559 } 569 }
560 570
561 ev_io_init (EV_A_ &linuxaio_epoll_w, linuxaio_epoll_cb, backend_fd, EV_READ); 571 ev_io_init (&linuxaio_epoll_w, linuxaio_epoll_cb, backend_fd, EV_READ);
562 ev_set_priority (&linuxaio_epoll_w, EV_MAXPRI); 572 ev_set_priority (&linuxaio_epoll_w, EV_MAXPRI);
563 ev_io_start (EV_A_ &linuxaio_epoll_w); 573 ev_io_start (EV_A_ &linuxaio_epoll_w);
564 ev_unref (EV_A); /* watcher should not keep loop alive */ 574 ev_unref (EV_A); /* watcher should not keep loop alive */
565 575
566 backend_modify = linuxaio_modify; 576 backend_modify = linuxaio_modify;
… …
588ecb_cold 598ecb_cold
589static void 599static void
590linuxaio_fork (EV_P) 600linuxaio_fork (EV_P)
591{ 601{
592 linuxaio_submitcnt = 0; /* all pointers were invalidated */ 602 linuxaio_submitcnt = 0; /* all pointers were invalidated */
593 linuxaio_free_iocp (EV_A); /* this frees all iocbs, which is very heavy-handed */ 603 linuxaio_free_iocbp (EV_A); /* this frees all iocbs, which is very heavy-handed */
594 evsys_io_destroy (linuxaio_ctx); /* fails in child, aio context is destroyed */ 604 evsys_io_destroy (linuxaio_ctx); /* fails in child, aio context is destroyed */
595 605
596 linuxaio_iteration = 0; /* we start over in the child */ 606 linuxaio_iteration = 0; /* we start over in the child */
597 607
598 while (linuxaio_io_setup (EV_A) < 0) 608 while (linuxaio_io_setup (EV_A) < 0)

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