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Diffstat (limited to 'man/io_uring_prep_timeout_update.3')
-rw-r--r-- | man/io_uring_prep_timeout_update.3 | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/man/io_uring_prep_timeout_update.3 b/man/io_uring_prep_timeout_update.3 new file mode 100644 index 0000000..cb9ed12 --- /dev/null +++ b/man/io_uring_prep_timeout_update.3 @@ -0,0 +1,98 @@ +.\" Copyright (C) 2022 Jens Axboe <axboe@kernel.dk> +.\" +.\" SPDX-License-Identifier: LGPL-2.0-or-later +.\" +.TH io_uring_prep_poll_timeout_update 3 "March 12, 2022" "liburing-2.2" "liburing Manual" +.SH NAME +io_uring_prep_timeoute_update \- prepare a request to update an existing timeout +.SH SYNOPSIS +.nf +.B #include <liburing.h> +.PP +.BI "void io_uring_prep_timeout_update(struct io_uring_sqe *" sqe "," +.BI " struct __kernel_timespec *" ts "," +.BI " __u64 " user_data "," +.BI " unsigned " flags ");" +.PP +.BI "void io_uring_prep_timeout_remove(struct io_uring_sqe *" sqe "," +.BI " __u64 " user_data "," +.BI " unsigned " flags ");" +.fi +.SH DESCRIPTION +.PP +These functions modify or cancel an existing timeout request. The submission +queue entry +.I sqe +is setup to arm a timeout update or removal specified by +.I user_data +and with modifier flags given by +.IR flags . +Additionally, the update request includes a +.I ts +structure, which contains new timeout information. + +For an update request, the +.I flags +member may contain a bitmask of the following values: +.TP +.B IORING_TIMEOUT_ABS +The value specified in +.I ts +is an absolute value rather than a relative one. +.TP +.B IORING_TIMEOUT_BOOTTIME +The boottime clock source should be used. +.TP +.B IORING_TIMEOUT_REALTIME +The realtime clock source should be used. +.TP +.B IORING_TIMEOUT_ETIME_SUCCESS +Consider an expired timeout a success in terms of the posted completion. +Normally a timeout that triggers would return in a +.B -ETIME +CQE +.I res +value. +.PP + +.SH RETURN VALUE +None +.SH ERRORS +These are the errors that are reported in the CQE +.I res +field. On success, +.B 0 +is returned. +.TP +.B -ENOENT +The timeout identified by +.I user_data +could not be found. It may be invalid, or triggered before the update or +removal request was processed. +.TP +.B -EALREADY +The timeout identified by +.I user_data +is already firing and cannot be canceled. +.TP +.B -EINVAL +One of the fields set in the SQE was invalid. For example, two clocksources +where given, or the specified timeout seconds or nanoseconds where < 0. +.TP +.B -EFAULT +io_uring was unable to access the data specified by +.IR ts . +.SH NOTES +As with any request that passes in data in a struct, that data must remain +valid until the request has been successfully submitted. It need not remain +valid until completion. Once a request has been submitted, the in-kernel +state is stable. Very early kernels (5.4 and earlier) required state to be +stable until the completion occurred. Applications can test for this +behavior by inspecting the +.B IORING_FEAT_SUBMIT_STABLE +flag passed back from +.BR io_uring_queue_init_params (3). +.SH SEE ALSO +.BR io_uring_get_sqe (3), +.BR io_uring_submit (3), +.BR io_uring_prep_timeout (3) |