io_uring_get_sqe - get the next available submission queue entry from the
submission queue
#include <liburing.h>
struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring);
The function gets the next available submission queue
entry from the submission queue belonging to the
ring param.
On success 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.
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.
io_uring_submit(3),
io_uring_sqe_set_data(3)