Submit requests to the submission queue and
wait for completion
# DESCRIPTION
The [io_uring_submit_and_wait] 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] and prepares the SQE, it can be submitted with
[io_uring_submit_and_wait]**.**
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.
# RETURN VALUE
On success [io_uring_submit_and_wait] returns the number of
submitted submission queue entries. On failure it returns **-errno**.
# SEE ALSO
[io_uring_queue_init_params], [io_uring_get_sqe],
[io_uring_submit], [io_uring_submit_and_wait_timeout]