ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libev/ev_iouring.c
(Generate patch)

Comparing libev/ev_iouring.c (file contents):
Revision 1.9 by root, Fri Dec 27 16:15:58 2019 UTC vs.
Revision 1.13 by root, Sat Dec 28 03:29:50 2019 UTC

87/* TODO: resize cq/sq size independently */ 87/* TODO: resize cq/sq size independently */
88 88
89#include <sys/timerfd.h> 89#include <sys/timerfd.h>
90#include <sys/mman.h> 90#include <sys/mman.h>
91#include <poll.h> 91#include <poll.h>
92#include <stdint.h>
92 93
93#define IOURING_INIT_ENTRIES 32 94#define IOURING_INIT_ENTRIES 32
94 95
95/*****************************************************************************/ 96/*****************************************************************************/
96/* syscall wrapdadoop - this section has the raw api/abi definitions */ 97/* syscall wrapdadoop - this section has the raw api/abi definitions */
173 __u32 resv[4]; 174 __u32 resv[4];
174 struct io_sqring_offsets sq_off; 175 struct io_sqring_offsets sq_off;
175 struct io_cqring_offsets cq_off; 176 struct io_cqring_offsets cq_off;
176}; 177};
177 178
179#define IORING_SETUP_CQSIZE 0x00000008
180
178#define IORING_OP_POLL_ADD 6 181#define IORING_OP_POLL_ADD 6
179#define IORING_OP_POLL_REMOVE 7 182#define IORING_OP_POLL_REMOVE 7
183#define IORING_OP_TIMEOUT 11
184#define IORING_OP_TIMEOUT_REMOVE 12
185
186/* relative or absolute, reference clock is CLOCK_MONOTONIC */
187struct iouring_kernel_timespec
188{
189 int64_t tv_sec;
190 long long tv_nsec;
191};
192
193#define IORING_TIMEOUT_ABS 0x00000001
180 194
181#define IORING_ENTER_GETEVENTS 0x01 195#define IORING_ENTER_GETEVENTS 0x01
182 196
183#define IORING_OFF_SQ_RING 0x00000000ULL 197#define IORING_OFF_SQ_RING 0x00000000ULL
184#define IORING_OFF_CQ_RING 0x08000000ULL 198#define IORING_OFF_CQ_RING 0x08000000ULL
185#define IORING_OFF_SQES 0x10000000ULL 199#define IORING_OFF_SQES 0x10000000ULL
186 200
187#define IORING_FEAT_SINGLE_MMAP 0x1 201#define IORING_FEAT_SINGLE_MMAP 0x00000001
188#define IORING_FEAT_NODROP 0x2 202#define IORING_FEAT_NODROP 0x00000002
189#define IORING_FEAT_SUBMIT_STABLE 0x4 203#define IORING_FEAT_SUBMIT_STABLE 0x00000004
190 204
191inline_size 205inline_size
192int 206int
193evsys_io_uring_setup (unsigned entries, struct io_uring_params *params) 207evsys_io_uring_setup (unsigned entries, struct io_uring_params *params)
194{ 208{
289 iouring_tfd = -1; 303 iouring_tfd = -1;
290 iouring_sq_ring = MAP_FAILED; 304 iouring_sq_ring = MAP_FAILED;
291 iouring_cq_ring = MAP_FAILED; 305 iouring_cq_ring = MAP_FAILED;
292 iouring_sqes = MAP_FAILED; 306 iouring_sqes = MAP_FAILED;
293 307
308 if (!have_monotonic) /* cannot really happen, but what if11 */
309 return -1;
310
294 for (;;) 311 for (;;)
295 { 312 {
296 iouring_fd = evsys_io_uring_setup (iouring_entries, &params); 313 iouring_fd = evsys_io_uring_setup (iouring_entries, &params);
297 314
298 if (iouring_fd >= 0) 315 if (iouring_fd >= 0)
299 break; /* yippie */ 316 break; /* yippie */
300 317
301 if (errno != EINVAL) 318 if (errno != EINVAL)
302 return -1; /* we failed */ 319 return -1; /* we failed */
320
321#if TODO
322 if ((~params.features) & (IORING_FEAT_NODROP | IORING_FEATURE_SINGLE_MMAP))
323 return -1; /* we require the above features */
324#endif
303 325
304 /* EINVAL: lots of possible reasons, but maybe 326 /* EINVAL: lots of possible reasons, but maybe
305 * it is because we hit the unqueryable hardcoded size limit 327 * it is because we hit the unqueryable hardcoded size limit
306 */ 328 */
307 329
378 { 400 {
379 /* we assume the sqe's are all "properly" initialised */ 401 /* we assume the sqe's are all "properly" initialised */
380 struct io_uring_sqe *sqe = iouring_sqe_get (EV_A); 402 struct io_uring_sqe *sqe = iouring_sqe_get (EV_A);
381 sqe->opcode = IORING_OP_POLL_REMOVE; 403 sqe->opcode = IORING_OP_POLL_REMOVE;
382 sqe->fd = fd; 404 sqe->fd = fd;
383 sqe->user_data = -1; 405 /* Jens Axboe notified me that user_data is not what is documented, but is
406 * some kind of unique ID that has to match, otherwise the request cannot
407 * be removed. Since we don't *really* have that, we pass in the old
408 * generation counter - if that fails, too bad, it will hopefully be removed
409 * at close time and then be ignored. */
410 sqe->user_data = (uint32_t)fd | ((__u64)(uint32_t)anfds [fd].egen << 32);
384 iouring_sqe_submit (EV_A_ sqe); 411 iouring_sqe_submit (EV_A_ sqe);
385 412
386 /* increment generation counter to avoid handling old events */ 413 /* increment generation counter to avoid handling old events */
387 ++anfds [fd].egen; 414 ++anfds [fd].egen;
388 } 415 }
429{ 456{
430 int fd = cqe->user_data & 0xffffffffU; 457 int fd = cqe->user_data & 0xffffffffU;
431 uint32_t gen = cqe->user_data >> 32; 458 uint32_t gen = cqe->user_data >> 32;
432 int res = cqe->res; 459 int res = cqe->res;
433 460
434 /* ignore fd removal events, if there are any. TODO: verify */
435 if (cqe->user_data == (__u64)-1)
436 abort ();//D
437
438 assert (("libev: io_uring fd must be in-bounds", fd >= 0 && fd < anfdmax)); 461 assert (("libev: io_uring fd must be in-bounds", fd >= 0 && fd < anfdmax));
439 462
440 /* documentation lies, of course. the result value is NOT like 463 /* documentation lies, of course. the result value is NOT like
441 * normal syscalls, but like linux raw syscalls, i.e. negative 464 * normal syscalls, but like linux raw syscalls, i.e. negative
442 * error numbers. fortunate, as otherwise there would be no way 465 * error numbers. fortunate, as otherwise there would be no way
443 * to get error codes at all. still, why not document this? 466 * to get error codes at all. still, why not document this?
444 */ 467 */
445 468
446 /* ignore event if generation doesn't match */ 469 /* ignore event if generation doesn't match */
470 /* other than skipping removal events, */
447 /* this should actually be very rare */ 471 /* this should actually be very rare */
448 if (ecb_expect_false (gen != (uint32_t)anfds [fd].egen)) 472 if (ecb_expect_false (gen != (uint32_t)anfds [fd].egen))
449 return; 473 return;
450 474
451 if (ecb_expect_false (res < 0)) 475 if (ecb_expect_false (res < 0))
452 { 476 {
453 //TODO: EINVAL handling (was something failed with this fd) 477 /*TODO: EINVAL handling (was something failed with this fd)*/
454 //TODO: EBUSY happens when? 478 /*TODO: EBUSY happens when?*/
455 479
456 if (res == -EBADF) 480 if (res == -EBADF)
457 { 481 {
458 assert (("libev: event loop rejected bad fd", res != -EBADF)); 482 assert (("libev: event loop rejected bad fd", res != -EBADF));
459 fd_kill (EV_A_ fd); 483 fd_kill (EV_A_ fd);
487iouring_overflow (EV_P) 511iouring_overflow (EV_P)
488{ 512{
489 /* we have two options, resize the queue (by tearing down 513 /* we have two options, resize the queue (by tearing down
490 * everything and recreating it, or living with it 514 * everything and recreating it, or living with it
491 * and polling. 515 * and polling.
492 * we implement this by resizing tghe queue, and, if that fails, 516 * we implement this by resizing the queue, and, if that fails,
493 * we just recreate the state on every failure, which 517 * we just recreate the state on every failure, which
494 * kind of is a very inefficient poll. 518 * kind of is a very inefficient poll.
495 * one danger is, due to the bios toward lower fds, 519 * one danger is, due to the bios toward lower fds,
496 * we will only really get events for those, so 520 * we will only really get events for those, so
497 * maybe we need a poll() fallback, after all. 521 * maybe we need a poll() fallback, after all.
509 else 533 else
510 { 534 {
511 /* we hit the kernel limit, we should fall back to something else. 535 /* we hit the kernel limit, we should fall back to something else.
512 * we can either poll() a few times and hope for the best, 536 * we can either poll() a few times and hope for the best,
513 * poll always, or switch to epoll. 537 * poll always, or switch to epoll.
514 * since we use epoll anyways, go epoll. 538 * TODO: is this necessary with newer kernels?
515 */ 539 */
516 540
517 iouring_internal_destroy (EV_A); 541 iouring_internal_destroy (EV_A);
518 542
519 /* this should make it so that on return, we don'T call any uring functions */ 543 /* this should make it so that on return, we don't call any uring functions */
520 iouring_to_submit = 0; 544 iouring_to_submit = 0;
521 545
522 for (;;) 546 for (;;)
523 { 547 {
524 backend = epoll_init (EV_A_ 0); 548 backend = epoll_init (EV_A_ 0);

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines