Mercurial > urweb

table channels : { Client : client, Channel : channel (string * int * float) }
  PRIMARY KEY Client

table dearlyDeparted : { Client : option client, When : time }

task clientLeaves = fn cli : client =>
                       dml (INSERT INTO dearlyDeparted (Client, When) VALUES ({[Some cli]}, CURRENT_TIMESTAMP));
                       debug "Our favorite client has LEFT!"

fun writeBack v =
    me <- self;
    r <- oneRow (SELECT channels.Channel FROM channels WHERE channels.Client = {[me]});
    send r.Channels.Channel v

fun main' () =
    me <- self;
    ch <- channel;
    dml (INSERT INTO channels (Client, Channel) VALUES ({[me]}, {[ch]}));

    buf <- Buffer.create;

    let
        fun receiverA () =
            v <- recv ch;
            Buffer.write buf ("A:(" ^ v.1 ^ ", " ^ show v.2 ^ ", " ^ show v.3 ^ ")");
            receiverA ()

        fun receiverB () =
            v <- recv ch;
            Buffer.write buf ("B:(" ^ v.1 ^ ", " ^ show v.2 ^ ", " ^ show v.3 ^ ")");
            error <xml>Bail out!</xml>;
            receiverB ()

        fun sender s n f =
            sleep 2000;
            rpc (writeBack (s, n, f));
            sender (s ^ "!") (n + 1) (f + 1.23)
    in
        return <xml><body onload={onDisconnect (alert "Server booted me");
                                  onConnectFail (alert "Connection failed");
                                  onServerError (fn s => alert ("Server error: " ^ s));
                                  spawn (receiverA ()); spawn (receiverB ()); sender "" 0 0.0}>
          <dyn signal={Buffer.render buf}/>
        </body></xml>
    end

fun main () = return <xml><body><form><submit action={main'}/></form></body></xml>
author	Anders Kaseorg <andersk@mit.edu>
date	Fri, 22 Nov 2013 09:36:14 -0500
parents	8a169fc0838b
children