NAME

       io_uring_get_sqe - get the next available submission queue entry from the submission queue

SYNOPSIS

       #include <liburing.h>

       struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring);

DESCRIPTION

       The  io_uring_get_sqe(3)  function gets the next available submission queue entry from the
       submission queue belonging to the ring param.

       On success io_uring_get_sqe(3) returns a pointer to the submission queue entry. On failure
       NULL is returned.

       If  a  submission  queue  entry  is  returned, it should be filled out via one of the prep
       functions such as io_uring_prep_read(3) and submitted via io_uring_submit(3).

       Note that neither io_uring_get_sqe nor the prep functions set  (or  clear)  the  user_data
       field    of    the    SQE.    If    the   caller   expects   io_uring_cqe_get_data(3)   or
       io_uring_cqe_get_data64(3) to return  valid  data  when  reaping  IO  completions,  either
       io_uring_sqe_set_data(3)  or  io_uring_sqe_set_data64(3)  MUST  have  been  called  before
       submitting the request.

RETURN VALUE

       io_uring_get_sqe(3) returns a pointer to the next submission queue event  on  success  and
       NULL  on  failure.  If NULL is returned, the SQ ring is currently full and entries must be
       submitted for processing before new ones can get allocated.

SEE ALSO

       io_uring_submit(3), io_uring_sqe_set_data(3)