io_uring_peek_cqe - check if an io_uring completion event is available
#include <liburing.h>
int io_uring_peek_cqe(struct io_uring *ring,
struct io_uring_cqe **cqe_ptr);
The function returns an IO completion from the queue
belonging to the
ring param, if one is readily available. On successful
return,
cqe_ptr param is filled with a valid CQE entry.
This function does not enter the kernel to wait for an event, an event is only
returned if it's already available in the CQ ring.
On success returns
0 and the cqe_ptr
parameter is filled in. On failure it returns
-EAGAIN.
io_uring_submit(3),
io_uring_wait_cqes(3),
io_uring_wait_cqe(3)