queue_actors.rb

require 'thread'

class Actor
  def initialize(send_queue, recv_queue)
    @send_queue = send_queue
    @recv_queue = recv_queue
  end

  def send(sym, *args)
    @send_queue.push([sym,*args])
  end

  def recv
    return @recv_queue.pop
  end

  def die
    Thread.current.kill
  end

end

class Master < Actor
  attr_accessor :results

  def initialize(send_queue, recv_queue, slave_count)
    super(send_queue, recv_queue)
    @slave_count = slave_count

    @threads = (0..slave_count).map do
      Thread.new do
        slave = Slave.new(@recv_queue, @send_queue)
        slave.loop
      end
    end
  end

  def kick_off
    ('a'..'z').each do |x|
      send(:puts, x)
    end
    @slave_count.times do
      send(:die)
    end
  end

  def wait_for_results
    @results = (0..@slave_count).map do
      self.recv
    end
  end

end


class Slave < Actor

  def loop
    while true do
      sym, *args = self.recv
      result = self.__send__(sym,*args)
      self.send(result)
    end
  end

  def puts(str)
    Kernel.puts str
    return str.succ
  end
end

send_queue, recv_queue = [Queue.new, Queue.new]
master = Master.new(send_queue, recv_queue, 20)
master.kick_off
master.wait_for_results
p master.results