.\" Copyright (C) 2021 Stefan Roesch <shr@fb.com>
.\"
.\" SPDX-License-Identifier: LGPL-2.0-or-later
.\"
.TH io_uring_submit 3 "November 15, 2021" "liburing-2.1" "liburing Manual"
.SH NAME
io_uring_submit - submit requests to the submission queue
.fi
.SH SYNOPSIS
.nf
.BR "#include <liburing.h>"
.PP
.BI "int io_uring_submit(struct io_uring *" ring ");"
.PP
.SH DESCRIPTION
.PP
The io_uring_submit() function submits the next events to the submission
queue belonging to the
.I ring.

After the caller retrieves a submission queue entry (SQE) with
.BR io_uring_get_sqe (3)
and prepares the SQE, it can be submitted with io_uring_submit().

.SH RETURN VALUE
On success
.BR io_uring_submit (3)
returns the number of submitted submission queue entries. On failure it returns
.B -errno.
.SH NOTES
For any request that passes in data in a struct, that data must remain
valid until the request has been successfully submitted. It need not remain
valid until completion. Once a request has been submitted, the in-kernel
state is stable. Very early kernels (5.4 and earlier) required state to be
stable until the completion occurred. Applications can test for this
behavior by inspecting the
.B IORING_FEAT_SUBMIT_STABLE
flag passed back from
.BR io_uring_queue_init_params (3).
In general, the man pages for the individual prep helpers will have a note
mentioning this fact as well, if required for the given command.
.SH SEE ALSO
.BR io_uring_get_sqe (3),  io_uring_submit_and_wait (3), io_uring_submit_and_wait_timeout (3)