NAME

       io_uring_wait_cqe_nr - wait for one or more io_uring completion events

SYNOPSIS

       #include <liburing.h>

       int io_uring_wait_cqe_nr(struct io_uring *ring,
                                struct io_uring_cqe **cqe_ptr,
                                unsigned wait_nr);

DESCRIPTION

       The io_uring_wait_cqe_nr(3) function returns wait_nr IO completion events from the queue belonging to the
       ring  param,  waiting for it if necessary. If the requested number of events are already available in the
       ring when invoked, no waiting will occur. The cqe_ptr param is filled in on success.

       After the caller has submitted a request  with  io_uring_submit(3),  the  application  can  retrieve  the
       completion with io_uring_wait_cqe(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.

RETURN VALUE

       On success io_uring_wait_cqe_nr(3) returns 0 and the cqe_ptr param is filled in. On  failure  it  returns
       -errno.   The  return  value indicates the result of waiting for a CQE, and it has no relation to the CQE
       result itself.

SEE ALSO

       io_uring_queue_init_params(3), io_uring_submit(3), io_uring_wait_cqes(3)

liburing-2.1                                    November 15, 2021                        io_uring_wait_cqe_nr(3)