gistfile1.txt

%%%-------------------------------------------------------------------
%%% @author greg <>
%%% @copyright (C) 2012, greg
%%% @doc
%%%
%%% @end
%%% Created : 29 Nov 2012 by greg <>
%%%-------------------------------------------------------------------
-module(ring).

%% API
-export([start/3, print/2, loop/1, loop_start/1]).

-record(state, {
	  num_procs
	  , msg_num
	  , msg
	  , proc_num=1
	  , pid
	  , first_pid=0
}).


%%%===================================================================
%%% API
%%%===================================================================

%%--------------------------------------------------------------------
%% @doc
%% @spec
%% @end
%%--------------------------------------------------------------------
start(ProcNum, MsgNum, Message) ->
    register(loop_start, spawn(ring, loop_start, [#state{num_procs=ProcNum, msg_num=MsgNum, msg=Message}])),
    loop_start ! start.


%%%===================================================================
%%% Internal functions
%%%===================================================================
loop_start(#state{num_procs=ProcNum}=State) ->
    receive
	start ->
	    F = fun(#state{proc_num=Num, pid=Pid}=NewState) ->
			case Num of
			    2 ->
				spawn(ring, loop, [NewState#state{proc_num=Num, pid=Pid, first_pid=Pid}]);
			    _ ->
				spawn(ring, loop, [NewState#state{proc_num=Num, pid=Pid}])
			end
		end,
	    [F(State#state{proc_num=N}) || N <- lists:seq(1, ProcNum)],
	    stop
    end.

loop(#state{proc_num=Num, pid=Pid, msg=Msg}=State) ->
    Pid ! {msg, Msg},
    receive
	stop ->
	    stop;
	{msg, Message} ->
	    print(Num, Message),
	    loop(State)
    end.


print(Num, Msg) ->
    lists:flatten(io_lib:format("Process: ~p recieved: ~p~n", [Num, Msg])).