message sending ring with eventmachine

#!/bin/env ruby

require 'rubygems'
require 'eventmachine'

def start_nodes(num_nodes, num_messages)
  EM.run {
    nodes = []
    num_nodes.times do
      nodes << EM.spawn{|message|
        case message.first
        when :setnext
          @nextpid = message[1]
          puts "I got setnext with node: %s" % @nextpid
        when :printlocal
          puts "I am #{self} and I have this: #{@nextpid}"
        when :sendmsg
          msg = message[1]
          countdown = message[2]
          puts "I am #{self} and I got message: #{msg} (#{countdown}) and am sending it on to: #{@nextpid}"
          if countdown > 0
            message[2] -= 1
            @nextpid.notify(message)
          else
            EM.stop
          end
        end
      }
    end

    nodes.each_with_index {|node,idx|
      next_node = nodes[(idx-1) % nodes.size]
      node.notify([:setnext, next_node])
    }
    nodes.each {|node|
      node.notify([:printlocal])
    }
    nodes.first.notify([:sendmsg, "Woot", num_messages*num_nodes])
  }
end

start_nodes(5, 5)