-module(ex3).
-compile(export_all).

loop() ->
  receive
    {print, Msg} ->
      io:format("~s~n", [Msg]),
      loop();
    exit -> ok
  end.

start(AnAtom, Fun) ->
  global:trans({funLock, AnAtom}, fun() ->
                           case global:whereis_name(AnAtom) of
                             undefined ->
                               Pid = spawn(Fun),
                               global:register_name(AnAtom, Pid);
                             _ ->
                               io:format("Function already registered.~n")
                           end end).