Function lks_process_while

pub fn lks_process_while(
    watch: Option<&WatchIDRef>,
    timeout: Stamp,
) -> LkResult<isize>

process callbacks until either:

The timeout has elapsed (0) if A watch id is given: => The watch was matched and the cb called: Positive if finished, negative if still active if No watch id is given: => # of new points processed *