adam@10: (** Reactive view of the current time *)
adam@10: 
adam@11: type t = {
adam@11:      Source : source time, (* Server time as of last tick event *)
adam@11:      Skew : source int,    (* How many seconds do we add to the local clock to match the server clock? *)
adam@11:      Period : int          (* How many milliseconds between ticks? *)
adam@11: }
adam@10: 
adam@10: fun create ms =
adam@10:     tm <- now;
adam@10:     t <- source tm;
adam@11:     sk <- source 0;
adam@11:     return {Source = t, Skew = sk, Period = ms}
adam@10: 
adam@10: fun start t =
adam@10:     let
adam@10:         fun loop () =
adam@10:             sleep t.Period;
adam@10:             tm <- now;
adam@11:             sk <- get t.Skew;
adam@11:             set t.Source (addSeconds tm sk);
adam@10:             loop ()
adam@11: 
adam@11:         fun serverTime () = now
adam@10:     in
adam@11:         spawn (server <- rpc (serverTime ());
adam@11:                local <- now;
adam@17:                set t.Skew (diffInSeconds local server));
adam@10:         spawn (loop ())
adam@10:     end
adam@10: 
adam@10: fun signal t = Basis.signal t.Source