/**************************************************************************
 
     Demo program for peer multitasking

  Running the query init(N) will create N remote peers running copies
  of the tcl demo program. The tcl demo program is assumed to be in 
  the same directory as this program, its ECLiPSe counterpart.

  Each tcl remote peer can participate in peer multitasking. A peer
  multitasking phase is started by the query go_multi/0. To hand control
  over to a specific peer, use go_one/1.

  This program is described in the Tcl Peer Multitasking chapter of the
  Embedding Manual

 **************************************************************************/

init(N) :-
        (for(I,1,N) do 
             remote_connect_setup(localhost/Port, Peer, Sock),
             % start the remote peer program...
             exec(["example_multi.tcl", "--", "-h", "localhost", "-p", Port],
                  [], _Pid),
             (remote_connect_accept(Peer, Sock, 10, post_attach(Peer), "", _) ->
                  true ; close(Sock)
             )
        ).

post_attach(Peer) :-
        recorda(multi_peers, Peer),
        printf("Created peer %w%n", [Peer]),
        set_event_handler(Peer, disconnect_handler/1).


disconnect_handler(Peer) :-
        erase(multi_peers, Peer),
        writeln(finished-Peer).

go_multi :-
        writeln("start multitasking phase...."),
        block(peer_do_multitask(demo), peer_multitask_empty,
                      writeln("No peers are registered for multitasking.")),
        writeln("end multitasking phase....").

go_one(Peer) :-
        printf("transferring to peer %w%n", [Peer]),
        once(recorded(multi_peers, Peer)), 
        remote_yield(Peer),
        printf("Return from peer %w%n", [Peer]).