Function io_uring_submit_and_wait_timeout 

pub unsafe extern "C" fn io_uring_submit_and_wait_timeout(
    ring: *mut io_uring,
    cqe_ptr: *mut *mut io_uring_cqe,
    wait_nr: c_uint,
    ts: *mut __kernel_timespec,
    sigmask: *mut sigset_t,
) -> c_int

Submit requests to the submission queue and wait for the completion with timeout

DESCRIPTION

The io_uring_submit_and_wait_timeout function submits the next requests from the submission queue belonging to the ring and waits for wait_nr completion events, or until the timeout ts expires. The completion events are stored in the cqe_ptr array.

The sigmask specifies the set of signals to block. If set, it is equivalent to atomically executing the following calls:

sigset_t origmask;

pthread_sigmask(SIG_SETMASK, &sigmask, &origmask);
ret = io_uring_submit_and_wait_timeout(ring, cqe, wait_nr, ts, NULL);
pthread_sigmask(SIG_SETMASK, &origmask, NULL);

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_timeout.

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_timeout returns the number of submitted submission queue entries. On failure it returns -errno. Note that in earlier versions of the liburing library, the return value was 0 on success. The most common failure case is not receiving a completion within the specified timeout, -ETIME is returned in this case.

SEE ALSO

io_uring_queue_init_params, io_uring_get_sqe, io_uring_submit, io_uring_submit_and_wait, io_uring_wait_cqe