Copyright (C) 2021 Stefan Roesch <shr@fb.com>

SPDX-License-Identifier: LGPL-2.0-or-later

io_uring_submit_and_wait - submit requests to the submission queue and wait for completion

 #include <liburing.h> 

 "int io_uring_submit_and_wait(struct io_uring *" ring ","  " unsigned " wait_nr ");" 

The io_uring_submit_and_wait (3) function submits the next requests from the submission queue belonging to the ring and waits for wait_nr completion events. After the caller retrieves a submission queue entry (SQE) with io_uring_get_sqe (3) and prepares the SQE, it can be submitted with io_uring_submit_and_wait (3) . Ideally used with a ring setup with IORING_SETUP_SINGLE_ISSUER | IORING_SETUP_DEFER_TASKRUN as that will greatly reduce the number of context switches that an application will see waiting on multiple requests.

On success io_uring_submit_and_wait (3) returns the number of submitted submission queue entries. On failure it returns -errno . io_uring_queue_init_params (3), io_uring_get_sqe (3), io_uring_submit (3), io_uring_submit_and_wait_timeout (3)