io_uring_peek_cqe - check if an io_uring completion event is available
Contents
Description
The io_uring_peek_cqe(3) 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.
The io_uring_peek_batch_cqe(3) function returns up to count request completions in cqe_ptrs belonging to
the ring param, if they are readily available. It will not enter the kernel, unless the CQ ring is in an
overflow condition. Upon successful return, cqe_ptrs are filled with the number of events indicated by
the return value.
Name
io_uring_peek_cqe - check if an io_uring completion event is available
Return Value
On success io_uring_peek_cqe(3) returns 0 and the cqe_ptr parameter is filled in. On success
io_uring_peek_batch_cqe(3) returns the number of completions filled in. On failure, they may return
-EAGAIN.
See Also
io_uring_submit(3), io_uring_wait_cqes(3), io_uring_wait_cqe(3) liburing-2.2 March 12, 2022 io_uring_peek_cqe(3)
Synopsis
#include<liburing.h>intio_uring_peek_cqe(structio_uring*ring,structio_uring_cqe**cqe_ptr);intio_uring_peek_batch_cqe(structio_uring*ring,structio_uring_cqe**cqe_ptrs,unsignedcount);
