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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | SEE ALSO | COLOPHON |
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io_uring_prep_poll_add(3) liburing Manual io_uring_prep_poll_add(3)
io_uring_prep_poll_add - prepare a poll request
#include <poll.h>
#include <liburing.h>
void io_uring_prep_poll_add(struct io_uring_sqe *sqe,
int fd,
unsigned poll_mask);
void io_uring_prep_poll_multishot(struct io_uring_sqe *sqe,
int fd,
unsigned poll_mask);
The io_uring_prep_poll_add(3) function prepares a poll request.
The submission queue entry sqe is setup to use the file descriptor
fd that should get polled, with the events desired specified in
the poll_mask argument.
The default behavior is a single-shot poll request. When the
specified event has triggered, a completion CQE is posted and no
more events will be generated by the poll request.
io_uring_prep_poll_multishot(3) behaves identically in terms of
events, but it persists across notifications and will repeatedly
post notifications for the same registration. A CQE posted from a
multishot poll request will have IORING_CQE_F_MORE set in the CQE
flags member, indicating that the application should expect more
completions from this request. If the multishot poll request gets
terminated or experiences an error, this flag will not be set in
the CQE. If this happens, the application should not expect
further CQEs from the original request and must reissue a new one
if it still wishes to get notifications on this file descriptor.
None
The CQE res field will contain the result of the operation, which
is a bitmask of the events notified. See the poll(2) man page for
details. Note that where synchronous system calls will return -1
on failure and set errno to the actual error value, io_uring never
uses errno. Instead it returns the negated errno directly in the
CQE res field.
io_uring_get_sqe(3), io_uring_submit(3), poll(2), epoll_ctl(3)
This page is part of the liburing (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 is not part of the original manual page), send a mail to
man-pages@man7.org
liburing-2.2 March 12, 2022 io_uring_prep_poll_add(3)
Pages that refer to this page: io_uring_prep_poll_add(3), io_uring_prep_poll_multishot(3), io_uring_prep_poll_update(3)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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