pub unsafe fn io_uring_prep_timeout_update(
sqe: *mut io_uring_sqe,
ts: *const __kernel_timespec,
user_data: __u64,
flags: c_uint,
)Expand description
Prepare a request to update an existing timeout
§DESCRIPTION
These functions modify or cancel an existing timeout request. The submission queue entry sqe is setup to arm a timeout update or removal specified by user_data and with modifier flags given by flags. Additionally, the update request includes a ts structure, which contains new timeout information.
For an update request, the flags member may contain a bitmask of the following values:
IORING_TIMEOUT_ABS
The value specified in ts is an absolute value rather than a relative
one.
The timeout remove command does not currently accept any flags.
§RETURN VALUE
None
§ERRORS
These are the errors that are reported in the CQE res field. On success, 0 is returned.
-ENOENT
The timeout identified by user_data could not be found. It may be
invalid, or triggered before the update or removal request was
processed.
-EALREADY
The timeout identified by user_data is already firing and cannot be
canceled.
-EINVAL
One of the fields set in the SQE was invalid. For example, two
clocksources were given, or the specified timeout seconds or nanoseconds
were < 0.
-EFAULT
io_uring was unable to access the data specified by ts.
§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 IORING_FEAT_SUBMIT_STABLE flag passed back from io_uring_queue_init_params.