gistfile1.txt

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

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

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


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

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


init(#state{num_procs=NumProcs, proc_num=Num, first_pid=Pid,
	    msg=Msg, msg_num=NMsg}) when NumProcs == Num ->
    loop({Num, Pid, Msg, NMsg});

init(#state{proc_num=Num, msg=Msg, msg_num=NMsg}=State) when Num == 1 ->
    Pid = spawn(ring, init, [State#state{proc_num=Num+1, first_pid=self()}]),
    loop({Num, Pid, Msg, NMsg});

init(#state{proc_num=Num, msg=Msg, msg_num=NMsg}=State) ->
    Pid = spawn(ring, init, [State#state{proc_num=Num+1}]),
    loop({Num, Pid, Msg, NMsg}).


%%%===================================================================
%%% Internal functions
%%%===================================================================
loop({Num, Pid, Msg, NMsg}) ->
    timer:sleep(100),
    [Pid ! {msg, Msg, X} || X <- lists:seq(1, NMsg)],
    receive
	{msg, Message, NMsg} ->
	    print(Num, Message, NMsg),
	    stop;
	{msg, Message, GMsg} ->
	    print(Num, Message, GMsg),
	    loop({Num, Pid, Msg, NMsg});
	stop ->
	    stop;
	_ ->
	    {error, invalid_message}
    end.


print(Num, Msg, NMsg) ->
    io:format("Process: ~p recieved: ~p times: ~p~n", [Num, Msg, NMsg]).