Erlang Ring example

ring.erl

-module(ring).
-export([build/1, ring_node/2, loop/1]).

build(N) ->
  Manager = self(),
  register(ring, Manager),
  Root = spawn(?MODULE, ring_node, [null, Manager]),
  Root ! {create, N},
  loop(N).

loop(N) ->
  receive
    ok ->
      io:format("Ring was built~n"),
      send_messages(N),
      loop(N);

    {message, finished} -> io:format("It finished~n");

    {message, Value} ->
      loop(N)
  end.

send_messages(0) ->
  ring ! {message, finished};

send_messages(N) ->
  ring ! {message, N},
  send_messages(N-1).

ring_node(ChildPid, Manager) ->
  receive
    {create, 0} ->
      Manager ! ok,
      ring_node(ChildPid, Manager);

    {create, N} ->
      Child = spawn(?MODULE, ring_node, [null, Manager]),
      Child ! {create, N-1},
      ring_node(Child, Manager)
  end.