io_uring_for_each_cqe - iterate pending completion events

       The  io_uring_for_each_cqe(3)  is  a  macro  helper that iterates completion events belonging to the ring
       using head as a temporary iterator, and points cqe to each pending event when iterating.

       This helper provides an efficient way to iterate all pending events in the ring, and then  advancing  the
       CQ  ring  by  calling  io_uring_cq_advance(3) with the number of CQEs consumed when done. As updating the
       kernel visible CQ ring state involves an ordered write, doing it once for a  number  of  events  is  more
       efficient than handling each completion separately and calling io_uring_cqe_seen(3) for each of them.

       void handle_cqes(struct io_uring *ring)
       {
            struct io_uring_cqe *cqe;
            unsigned head;
            unsigned i = 0;

            io_uring_for_each_cqe(ring, head, cqe) {
                 /* handle completion */
                 printf("cqe: %d\n", cqe->res);
                 i++;
            }

            io_uring_cq_advance(ring, i);
       }

       io_uring_for_each_cqe - iterate pending completion events

       None

io_uring_wait_cqe_timeout(3),    io_uring_wait_cqe(3),    io_uring_wait_cqes(3),    io_uring_cqe_seen(3),
       io_uring_buf_ring_cq_advance(3)

liburing-2.4                                      June 04, 2023                         io_uring_for_each_cqe(3)

#include<liburing.h>io_uring_for_each_cqe(structio_uring*ring,unsignedhead,structio_uring_cqe*cqe){}