.\" Copyright (C) 2020 Jens Axboe <axboe@kernel.dk>
.\" Copyright (C) 2020 Red Hat, Inc.
.\"
.\" SPDX-License-Identifier: LGPL-2.0-or-later
.\"
.TH io_uring_queue_init 3 "July 10, 2020" "liburing-0.7" "liburing Manual"
.SH NAME
io_uring_queue_init - setup io_uring submission and completion queues
.SH SYNOPSIS
.nf
.BR "#include <liburing.h>"
.PP
.BI "int io_uring_queue_init(unsigned " entries ", struct io_uring *" ring ,
.BI "                        unsigned " flags );
.fi
.PP
.SH DESCRIPTION
.PP
The io_uring_queue_init() function executes the io_uring_setup syscall to
initialize the submission and completion queues in the kernel with at least
.I entries
entries and then maps the resulting file descriptor to memory shared between the
application and the kernel.

On success io_uring_queue_init() returns 0 and
.I ring
will point to the shared memory containing the io_uring queues. On failure
-errno is returned.

.I flags
will be passed through to the io_uring_setup syscall (see 
.BR io_uring_setup (2)).

On success, the resources held by
.I ring
should be released via a corresponding call to
.BR io_uring_queue_exit (3).
.SH RETURN VALUE
.BR io_uring_queue_init (3)
returns 0 on success and -errno on failure.
.SH SEE ALSO
.BR io_uring_setup (2),
.BR mmap (2),
.BR io_uring_queue_exit (3)