NAME

       io_uring_prep_timeoute_update - prepare a request to update an existing timeout

SYNOPSIS

       #include <liburing.h>

       void io_uring_prep_timeout_update(struct io_uring_sqe *sqe,
                                         struct __kernel_timespec *ts,
                                         __u64 user_data,
                                         unsigned flags);

       void io_uring_prep_timeout_remove(struct io_uring_sqe *sqe,
                                         __u64 user_data,
                                         unsigned flags);

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.

       IORING_TIMEOUT_BOOTTIME
              The boottime clock source should be used.

       IORING_TIMEOUT_REALTIME
              The realtime clock source should be used.

       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 -ETIME CQE res value.

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  where
              given, or the specified timeout seconds or nanoseconds where < 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(3).

SEE ALSO

       io_uring_get_sqe(3), io_uring_submit(3), io_uring_prep_timeout(3)