| .\" Copyright (C) 2021 Stefan Roesch <shr@fb.com> |
| .\" |
| .\" SPDX-License-Identifier: LGPL-2.0-or-later |
| .\" |
| .TH io_uring_wait_cqe 3 "November 15, 2021" "liburing-2.1" "liburing Manual" |
| .SH NAME |
| io_uring_wait_cqe \- wait for one io_uring completion event |
| .SH SYNOPSIS |
| .nf |
| .B #include <liburing.h> |
| .PP |
| .BI "int io_uring_wait_cqe(struct io_uring *" ring "," |
| .BI " struct io_uring_cqe **" cqe_ptr ");" |
| .fi |
| .SH DESCRIPTION |
| .PP |
| The |
| .BR io_uring_wait_cqe (3) |
| function waits for an IO completion from the queue belonging to the |
| .I ring |
| param, waiting for it if necessary. If an event is already available in |
| the ring when invoked, no waiting will occur. The |
| .I cqe_ptr |
| param is filled in on success. |
| |
| After the caller has submitted a request with |
| .BR io_uring_submit (3), |
| the application can retrieve the completion with |
| .BR io_uring_wait_cqe (3). |
| |
| .SH RETURN VALUE |
| On success |
| .BR io_uring_wait_cqe (3) |
| returns 0 and the cqe_ptr parm is filled in. On failure it returns |
| .BR -errno . |
| The return value indicates the result of waiting for a CQE, and it has no |
| relation to the CQE result itself. |
| .SH SEE ALSO |
| .BR io_uring_submit (3), |
| .BR io_uring_wait_cqes (3) |
