client_server.exs

defmodule Ticker do
  @interval 2000
  @name :ticker

  def start do
    pid = spawn __MODULE__, :generator, [[]]
    :global.register_name(@name, pid)
  end

  def register(client_pid) do
    send :global.whereis_name(@name), {:register, client_pid}
  end

  def generator(client_pids) do
    receive do
      { :register, client_pid} ->
        IO.puts "register cliend #{inspect client_pid}"
        generator [client_pid | client_pids]
    after
      @interval ->
        client_pids
        |> Enum.each(fn client_pid ->
          send client_pid, {:tick}
        end)
        generator(client_pids)
    end
  end
end

defmodule Client do
  def start do
    pid = spawn __MODULE__, :receiver, []
    Ticker.register pid
  end

  def receiver do
    receive do
      {:tick} ->
        IO.puts "rec tick!"
        receiver
    end
  end
end