# DRb troubles, cannot Marshal or proxy objects successfully

**URL:** <https://www.ruby-forum.com/t/drb-troubles-cannot-marshal-or-proxy-objects-successfully/94802>\
**Category:** Ruby\
**Created:** [January 9, 2006, 10:07am UTC](https://www.ruby-forum.com/t/drb-troubles-cannot-marshal-or-proxy-objects-successfully/94802 "2006-01-09T10:07:29Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [January 9, 2006, 10:07am UTC](https://www.ruby-forum.com/t/drb-troubles-cannot-marshal-or-proxy-objects-successfully/94802/1 "2006-01-09T10:07:29Z")

</div>

I’ve been trying for hours trying ot get my DRb session store working.  
I can get it to work in a gerneralized way, but I need to add some  
validation to check the state of the session data, and keep track of  
it, in case I need to invalidate the session data, so a user doen’t  
track with stale data on a website.

My first tries, I noticed that the objects that were coming in to my  
Drb server were not being unmarshalled, This was fine if i just wanted  
to store the data, but I needed to see values inside. So I tried  
getting marshaling working. First i tried making class stubs for the  
classes that were coming over, but I would get :  
usr/lib/ruby/1.8/drb/drb.rb:582:in `load’:dump format error (user  
class)

So then I tried proxying the code, but the first time it comes across,  
I get:  
/usr/lib/ruby/1.8/drb/drb.rb:1094: `0x114475a is recycled object’  
(RangeError)

I’ve been searching all over the net and have only found some very  
vague information.

I hope someone can help me out here…

Here’s my code.  
======drb\_server.rb============  
#!/usr/bin/env ruby -w

# This is a session storage daemon, basically just a hash,

# which is enabled for DRb access. But it has timestamping,

# for expiration and a way for setting if the information is invalid.

require ‘drb/drb’

session\_hash = Hash.new  
session\_hash.instance\_eval { @mutex = Mutex.new; @user\_hash = Hash.new  
}  
TIMEOUT = 15 \* 60 # 15 minute Timeout

#uncomment these classes if you want to marshal  
#class User  
#end

# 

#class ActionController  
#end

# 

#class ActionController::Flash  
#end

# 

#class ActionController::Flash::FlashHash  
#end

class \<\<session\_hash

```
def []=(key, value)
    begin
        if value['user']
            user_id = value['user'][:id]
            if @user_hash[user_id]
                @user_hash[user_id] = (@user_hash[user_id]) << key
            else
                @user_hash[user_id] = [key]
            end
        end
    rescue
        #contains an unknown object type
    end
    @mutex.synchronize do
        super(key, [Time.now, value])
        value
    end
end

def [](key)
    instance = nil
    @mutex.synchronize do
        instance = super(key)
    end
    if instance
        # check the time
        last_access = instance[0]
        value = instance[1]
        if(Time.now <= last_access + TIMEOUT)
            #its within the timeout, update the new expiration
                self[key] = value
            return value
        else
            #it out of time, drop the session
            delete(key)
            return nil
        end
    else
        return nil
    end
end

def delete(key)
    @mutex.synchronize do
        super(key)
    end
end

def invalidate_data(user_id)
    if @user_hash
        # get the array of sessions that contain this user
        user_session = nil
        user_sessions = @user_hash[user_id] #get the array of

```

tracked sessions for this user

```
        user_sessions.each do |session_id|
            session = self[session_id]
            unless session
                #this session no longer exists, stop tracking the

```

session  
@user\_hash[user\_id] = user\_sessions.delete(session)  
return  
end  
session[‘user\_state’] = “INVALID”  
self[session\_id] = session  
end  
end  
end

end

DRb.start\_service(‘druby://127.0.0.1:9192’, session\_hash)  
DRb.thread.join  
======drb\_store.rb========

# this is a simple CGI Session class that contains a

# drb client

require ‘cgi’  
require ‘cgi/session’  
require ‘drb’

SERVER\_URL = ‘druby://localhost:9192’

class CGI #:nodoc:all  
class Session  
class DRbStore  
@@session\_data = DRbObject.new(nil, SERVER\_URL)

```
  def initialize(session, option=nil)
    @session_id = session.session_id
  end

  def restore
    @h = @@session_data[@session_id] || {}
  end

  def update
    @h.extend DRbUndumped #comment this line for Marshaling
    @@session_data[@session_id] = @h
  end

  def close
    update
  end

  def delete
    @@session_data.delete(@session_id)
  end

end

```

end  
end  
======/end files/=======

Please, if anyone can help, I’d be most grateful.

Sean