From: Tom <tom@...>
Date: 2007-08-23T08:29:30+09:00
Subject: Re: Process Rings (#135)

Hey guys... here's my attempt.  I'm a bit of n00b, so feedback
welcome!

I attacked this with DRb (distributed ruby), since it hadn't been
touched yet.  It meant taking a serious hit in performance, but it was
at least interesting.  It's threaded, but could be forked (haven't
tried that just yet).

Thanks!

---BEGIN SOLUTION---
# Num. 135
# process_rings.rb
require 'drb'

BasePort = 7654

class RingParent
  def initialize(processes = 3, cycles = 5)
    @processes = processes
    @cycles = cycles
    @message = "Message from parent\n"
  end

  def start
    spawn_processes
    connect_ring
    send_messages
  end

  def spawn_processes
    t = []
    for i in 0...@processes-1
      t << Thread.new do
        RingMember.new(BasePort+i, BasePort+i+1, self)
      end
    end
    t << Thread.new do
      RingMember.new(BasePort+@processes-1, BasePort)
    end
  end

  def connect_ring
    DRb.start_service
    @ring = DRbObject.new(nil, "druby://127.0.0.1:#{BasePort}")
  end

  def send_messages
    @start = Time.now
    @cycles.times do
      @ring.parent_receive("Hi ring!")
    end
  end

  def return_message(message)
    puts "Parent: Got message back- circulation time: #{Time.now -
@start}"
  end
end

class RingMember
  def initialize(port, next_port, parent = nil)
    @port = port
    @parent = parent
    @current_message = ""
    @next_member = connect_next(next_port)
    DRBService.new(self, @port)
  end

  def connect_next(port)
    DRb.start_service
    DRbObject.new(nil, "druby://127.0.0.1:#{port}")
  end

  def parent_receive(message)
    @current_message = message
    forward_message(@current_message)
  end

  def receive_message(message)
    begin
      message == @current_message ?
        (@parent.return_message(message);(@current_message = "")) :
        forward_message(message)
    rescue
      puts "#{@port}: Received duplicate message, couldn't talk to
parent: #{$!}"
    end
  end

  def forward_message(message)
    @next_member.receive_message(message)
  end

  def test(message)
    return "#{@port}: Got message #{message}"
  end
end

class DRBService
  def initialize(process, port)
    DRb.start_service("druby://:#{port}", process)
    DRb.thread.join
  end
end

processes = ARGV[0].to_i
cycles = ARGV[1].to_i
parent = RingParent.new(processes, cycles)




On Aug 22, 3:00 pm, "Adam Shelly" <adam.she...@gmail.com> wrote:
> On 8/22/07, James Edward Gray II <ja...@grayproductions.net> wrote:> On Aug 22, 2007, at 1:45 PM, Adam Shelly wrote:
> > > I've been thinking about virtual machines recently, so I decided to
> > > implement one in Ruby for this quiz.
>
> > That gets my vote for the craziest Ruby Quiz solution ever.  Wow!
>
> > You have no idea how much I regret that I wrote the quiz summary
> > earlier today.  :(
>
> You have no idea how much I regret that I had a bunch of real work to
> do and didn't have time to finish it up sooner.  :)
>
> I also wish I had time and a valid reason to keep working on extending
> the VM.  The first thing I'd do is find a good name for the
> language...
>
> -Adam