shower.rb

require 'thread'

class Actor
  class ActorDied < RuntimeError; end
  def self.queue
    @queue ||= Queue.new
  end

  def self.push(x)
    queue.push(x)
  end

  def self.die
    raise ActorDied
  end

  def self.run(&block)
    Thread.new do
      begin
        while true do
          self.instance_eval(&block)
        end
      rescue ActorDied => _
        break
      rescue Exception => e
        # understand an asynchronous exception. understand it.
        puts e
      end
    end
  end
end

module Actors
  def self.actor(clazz, &block)
    clazz.run(&block)
  end

  def self.const_missing(const_name)
    self.const_set(const_name, Class.new(Actor))
  end
end

describe Actors do
  it "actors can push messages onto an queue" do
    module Actors
      actor Shower do
        Soap.push(1)
        die
      end

      actor Soap do
        die
      end
    end

    Actors::Soap.queue.pop.should == 1
  end

  it "dies as soon as it is told to" do
    module Actors
      actor Shower do
        Soap.push(1)
        die
      end

      actor Soap do
        die
      end
    end

    Actors::Soap.queue.length.should == 1

  end
end