| .\" Copyright (C) 2021 Stefan Roesch <shr@fb.com> |
| .\" |
| .\" SPDX-License-Identifier: LGPL-2.0-or-later |
| .\" |
| .TH io_uring_wait_cqe_timeout 3 "November 15, 2021" "liburing-2.1" "liburing Manual" |
| .SH NAME |
| io_uring_wait_cqe_timeout \- wait for one io_uring completion event with timeout |
| .SH SYNOPSIS |
| .nf |
| .B #include <liburing.h> |
| .PP |
| .BI "int io_uring_wait_cqe_timeout(struct io_uring *" ring "," |
| .BI " struct io_uring_cqe **" cqe_ptr "," |
| .BI " struct __kernel_timespec *" ts ");" |
| .fi |
| .SH DESCRIPTION |
| .PP |
| The |
| .BR io_uring_wait_cqe_timeout (3) |
| function waits for one IO completion to be available from the queue belonging |
| to the |
| .I ring |
| param, waiting for it if necessary or until the timeout |
| .I ts |
| expires. 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. |
| |
| If |
| .I ts |
| is specified and an older kernel without |
| .B IORING_FEAT_EXT_ARG |
| is used, the application does not need to call |
| .BR io_uring_submit (3) |
| before calling |
| .BR io_uring_wait_cqes (3). |
| For newer kernels with that feature flag set, there is no implied submit |
| when waiting for a request. |
| |
| .SH RETURN VALUE |
| On success |
| .BR io_uring_wait_cqes (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_cqe_timeout (3), |
| .BR io_uring_wait_cqe (3) |
