Movatterモバイル変換

io_uring_prep_epoll_wait(3) — Linux manual page

io_uring_prep_epoll_wait(3)  liburing Manualio_uring_prep_epoll_wait(3)

NAME        top

       io_uring_prep_epoll_wait - prepare an epoll wait request

SYNOPSIS        top

#include <sys/epoll.h>#include <liburing.h>void io_uring_prep_epoll_wait(struct io_uring_sqe *sqe,intfd,struct epoll_event *events,intmaxevents,unsigned flags);"

DESCRIPTION        top

       Theio_uring_prep_epoll_wait(3) function prepares an epoll_wait       request. The submission queue entrysqe is setup to wait on a       maximum ofmaxevents events on the epoll file descriptor indicated       byfd, and filling the received events into the memory pointed to       byevents.       This function prepares an asyncepoll_wait(2) request. See that       man page for details. The use case is mostly for legacy event       loops, where certain file descriptors may still be using epoll for       readiness notifications. Normally this would necessitate using       epoll_wait with the io_uring fd added to that set as well, which       is suboptimal as epoll doesn't provide the same kind of fine       grained batch control and wakeup reductions that io_uring does. By       using io_uring to read epoll events, the event loop can be       entirely switched to io_uring, and reap the benefits of batch       waiting and context switch reductions.

RETURN VALUE        top

       None

ERRORS        top

       The CQEres field will contain the result of the operation. See       the related man page for details on possible values. Note that       where synchronous system calls will return-1on failure and seterrno to the actual error value, io_uring never useserrno.       Instead it returns the negatederrno directly in the CQEres       field.

SEE ALSO        top

io_uring_get_sqe(3),io_uring_submit(3),epoll_wait(2)

COLOPHON        top

       This page is part of theliburing (A library for io_uring)       project.  Information about the project can be found at        ⟨https://github.com/axboe/liburing⟩.  If you have a bug report for       this manual page, send it to io-uring@vger.kernel.org.  This page       was obtained from the project's upstream Git repository       ⟨https://github.com/axboe/liburing⟩ on 2025-08-11.  (At that time,       the date of the most recent commit that was found in the       repository was 2025-08-02.)  If you discover any rendering       problems in this HTML version of the page, or you believe there is       a better or more up-to-date source for the page, or you have       corrections or improvements to the information in this COLOPHON       (which isnot part of the original manual page), send a mail to       man-pages@man7.orgliburing-2.10                 March 6, 2025io_uring_prep_epoll_wait(3)

Pages that refer to this page:io_uring_prep_epoll_wait(3)

HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH.