Starts a few processes, who waits a randomly long time before calling back.

late_print.ex

defmodule LatePrint do

  def late_print(0) do
    handle_message
  end


  def late_print(n) do
    parent = self
    spawn_link(fn ->
      << a :: 32, b :: 32, c :: 32 >> = :crypto.rand_bytes(12)
      :random.seed(a,b,c)
      r = :random.uniform(10000)
      IO.puts(r)
      :timer.sleep(r)
      send parent, {:msg, "hello world from #{n}"}
    end)
    late_print(n-1)
  end

  def handle_message do
    receive do
      {:msg, contents} -> IO.puts contents
    end
    handle_message
  end

end

LatePrint.late_print(10)