From: m_seki@...
Date: 2001-11-27T08:05:41+09:00
Subject: [ruby-talk:26569] Re: DRbUndumped question


Hi, Phil. (repost)

> here's part of the Client.rb file:
> require 'drb'
> class Client
> 
>    def initialize
>    ...
>    end
> 
>    def run(taskObj, *args)
>       taskObj.run(args) #an object that must respond to 'run'   
>    end
> end
> 
> if $0 == __FILE__
>    clientObj = Client.new
>    DRb.start_service('druby://0.0.0.0:9000',clientObj)
>    DRb.thread.join
> end
> #end of Client.rb
> 
> Here's the Task.rb file which defines a Task class and then attempts to 
> send a Task object to Client running on 'remote':
> 
> require 'drb'
> class Task
>    include DRb::DRbUndumped
>    def initialize
>    end
> 
>    def run(*args)
>       puts "Task::Run - running #{args}"
>    end
> end
> 
> if $0 == __FILE__
>    DRb.start_service()
>    client = DRbObject.new(nil,'druby://remote:9000')
>    puts client.run(Task.new, "ftp","xyz","abc")
> end
> #end of Task.rb

> So, my question is, what exactly does including DRbUndumped do?  (I 
> thought it was to mixin to your own classes so that they could be passed 
> by reference to the remote DRbObject, but now I think I misunderstand 
> how to use it).

Yes, DRbUndumped is mix-in class for passed by reference.

I drew sequence chart. 

  * http://www2a.biglobe.ne.jp/~seki/ruby/ruby-talk-26474.png


In the case of include DRbUndumped:
A Task object is in 'local', and pass a referecne of it.
'run' message is received by aTask in 'local'.


The other case:
A Task object is in 'local', and pass a copy of it to 'remote'.
'run' message is received by aTask in 'remote'.


Seki.
(sorry, I'm verrry poor at English. Please see the chart)