From: Masatoshi SEKI <m_seki@...>
Date: 2001-05-16T03:07:25+09:00
Subject: [ruby-talk:15196] Re: SV:  DRuby/Rinda/TupleSpace Dokumentation


Hi

> The problems I have with DRuby are
> 
> .) That there is no "name service". Each object needs it's own server on a
> different port.


* dRuby is not provide "name service".
* Each DRbServer needs different port, Not each object.


> .) That (if I understood correctly) the server works on an _instance_ of an
> object, not on a class. This means that the member variable of the object
> are shared between the different clients.

* DRbServer has a front-object. It's a front-gate of the Distributed System.
* DRbServer works on many objects. 


-- ns.rb --
# Simple NameService.
require 'drb/drb'

DRb.start_service(ARGV.shift, {})
puts DRb.uri
puts '[enter] to exit'
gets


-- q.rb --
# Queue factory
require 'thread'
require 'drb/drb'
require 'drb/timeridconv'

class Queue
  include DRbUndumped
end

class QueueFactory
  include DRbUndumped
  def new
    SizedQueue.new(4)
  end
end

begin
  name_service_uri = ARGV.shift || raise
rescue
  puts "usage : #{$0} <NameService URI>"
  exit 1
end  

DRb.install_id_conv(TimerIdConv.new)  
DRb.start_service

ns = DRbObject.new(nil, name_service_uri)

# factory = DRbObject.new(Queue)
factory = QueueFactory.new

ns['queue'] = factory

puts '[enter] to exit'
gets


-- qi.rb --
# Create a queue, and regist to NameService
require 'drb/drb'

begin
  name_service_uri = ARGV.shift || raise
  queue_name = ARGV.shift || raise
rescue
  puts "usage : #{$0} <NameService URI> <QueueName>"
  exit 1
end  

DRb.start_service
ns = DRbObject.new(nil, name_service_uri)

p ns.size

queue_factory = ns['queue']
queue = queue_factory.new
p queue
ns[queue_name] = queue

10.times do |n|
  queue.push n
end
queue.push nil


-- qo.rb --
# Consumer. delete queue from NameService
require 'drb/drb'

begin
  name_service_uri = ARGV.shift || raise
  queue_name = ARGV.shift || raise
rescue
  puts "usage : #{$0} <NameService URI> <QueueName>"
  exit 1
end  

DRb.start_service

ns = DRbObject.new(nil, name_service_uri)
queue = ns[queue_name]

while elem = queue.pop
  puts elem + elem
end

ns[queue_name] = nil

-- How to play

HOST A
% ruby ns.rb druby://hostA:12345

HOST B
% ruby q.rb druby://hostA:12345

HOST C
% ruby qi.rb druby://hostA:12345 test_queue_name

HOST D
% ruby qo.rb druby://hostA:12345 test_queue_name



Seki.