NAME

       io_uring_prep_poll_update - update an existing poll request

SYNOPSIS

       #include <poll.h>
       #include <liburing.h>

       void io_uring_prep_poll_update(struct io_uring_sqe *sqe,
                                      __u64 old_user_data,
                                      __u64 new_user_data,
                                      unsigned poll_mask,
                                      unsigned flags);

DESCRIPTION

       The  io_uring_prep_poll_update(3)  function prepares a poll update request. The submission
       queue entry sqe is setup to update a poll request identified by  old_user_data,  replacing
       it  with  the  new_user_data information. The poll_mask arguments contains the new mask to
       use for the poll request, and flags argument contains modifier flags telling io_uring what
       fields to update.

       The flags modifier flags is a bitmask and may contain and OR'ed mask of:

       IORING_POLL_UPDATE_EVENTS
              If  set,  the poll update request will replace the existing events being waited for
              with the ones specified in the poll_mask argument to the function.

       IORING_POLL_UPDATE_USER_DATA
              If set, the poll update request will update the existing user_data of  the  request
              with the value passed in as the new_user_data argument.

       IORING_POLL_ADD_MULTI
              If set, this will change the poll request from a singleshot to a multishot request.
              This must be used along with IORING_POLL_UPDATE_EVENTS as the event field  must  be
              updated to enable multishot.

RETURN VALUE

       None

ERRORS

       These are the errors that are reported in the CQE res field. On success, 0 is returned.

       -ENOENT
              The  request identified by user_data could not be located. This could be because it
              completed before the cancelation request was issued, or if an invalid identifier is
              used.

       -EINVAL
              One of the fields set in the SQE was invalid.

       -EALREADY
              The execution state of the request has progressed far enough that cancelation is no
              longer possible. This should normally mean that it will  complete  shortly,  either
              successfully, or interrupted due to the cancelation.

       -ECANCELED
              IORING_POLL_UPDATE_EVENTS  was set and an error occurred re-arming the poll request
              with the new mask.  The original poll request is terminated if  this  happens,  and
              that termination CQE will contain the reason for the error re-arming.

SEE ALSO

       io_uring_get_sqe(3),             io_uring_submit(3),            io_uring_prep_poll_add(3),
       io_uring_prep_poll_multishot(3)