simple actor

drip_actor.rb

require 'drip'

module Actor
  class Ether
    def initialize
      @drip = Drip.new(nil)
      Thread.current['channel'] = create_channel
    end
    
    def create_channel
      key = @drip.write(Process.pid, 'spawn')
      Channel.new(self, key)
    end
    
    def send(to, from, message)
      @drip.write([from, message], to)
    end
    
    def receive(to, cursor)
      cursor, value, = @drip.read_tag(cursor, to)[0]
      return cursor, value
    end
    
    class Channel
      def initialize(ether, key)
        @ether = ether
        @addr = key.to_s(36)
        @cursor = key
      end
      attr_reader :addr
      
      def spawn(*args)
        ch = @ether.create_channel
        Thread.new(ch, args) do |ch, args|
          Thread.current['channel'] = ch
          yield(*args)
        end
        ch.addr
      end
      
      def send(to, message)
        @ether.send(to, @addr, message)
      end
      
      def receive
        @cursor, value = @ether.receive(@addr, @cursor)
        value
      end
    end
  end

  module_function
  def init
    Ether.new
  end

  def send(to, message)
    Thread.current['channel'].send(to, message)
  end

  def receive
    Thread.current['channel'].receive
  end

  def spawn(*args, &block)
    Thread.current['channel'].spawn(*args, &block)
  end
end

if __FILE__ == $0
  Actor.init

  echo_pid = Actor.spawn do
    begin
    while true
      addr, message = Actor.receive
      p message
    end
    rescue
      p $!
    end
    
  end
  
  Actor.send(echo_pid, 'hello')
  sleep 1

  def account
    dict = Hash.new(0)
    loop do
      from, message = Actor.receive
      case message[0]
      when 'balance'
        user = message[1]
        Actor.send(from, ['balance', user, dict[user]])
      when 'deposit'
        _, user, money = message
        dict[user] += money
        Actor.send(from, ['balance', user, dict[user]])
      end
    end
  end
  
  acc = Actor.spawn do
    account
  end
  
  10.times do |n|
    2.times do
      Actor.spawn(n, acc) do |uid, acc_pid|
        Actor.send(acc_pid, ['balance', uid])
        _, value = Actor.receive
        p value
        
        Actor.send(acc_pid, ['deposit', uid, 10])
        _, value = Actor.receive
        p value
      end
    end
  end
    
  sleep 10
end