From: Miles Keaton <mileskeaton@...>
Date: 2005-03-30T17:53:44+09:00
Subject: Re: DRb / dRuby - freezes on DRb::DRbUndumped - any ideas?

On Mon, 28 Mar 2005 00:56:10 -0800, Miles Keaton <mileskeaton@gmail.com> wrote:
> Using the "Remote objects under dRuby" example here:
> http://www.ruby-doc.org/stdlib/libdoc/drb/rdoc/classes/DRb.html
> Following it, exactly.
> 
> But it freezes when it tries to call this line:
> logger.log("Hello, world!")
> Everything works until that point.
> 
> This same freeze happens with
> http://pragmaticprogrammer.com/titles/ruby/code/smp670.html
> 
> What they all have in common is DRb::DRbUndumped - so I'm guessing
> that's the problem.
> 
> I'm running Ruby 1.8.2 on different/remote computers to do this test
> (client names server by IP address.)
> 
> It works when I run both on the same computer, but as soon as I try to
> put client and server on different computers, it seems unable to use
> objects passed by reference.
> 
> NOTE where it froze, above.  It's able to pass the object by
> reference.  It receives it back on the client.  But when the client
> tries to use it, that's when it freezes.
> 
> I've tried this on various FreeBSD and Mac OS X computers, at home and
> work, without firewalls.  All other DRb code works fine except when
> using DRbUndumped.


I started putting little "pp" statements inside drb.rb to find out
what was happening.

Is there any reason that URI should ever be nil?

See here:

~~~ DRbConn.open called
REMOTE_URI: "druby://10.0.1.1:2001"
@mutex: #<Mutex:0x6d52a0 @locked=false, @waiting=[]>
CONN: nil

### DRbProtocol.open has been called
URI: "druby://10.0.1.1:2001"
FIRST?: true
PROTOCOL:DRb::DRbTCPSocket
=== DRbTCPSocket.open has been called
URI: "druby://10.0.1.1:2001"
Parsing uri...
HOST: "10.0.1.1"
PORT: 2001
OPTION: nil
Doing TCPSocket.open(host, port)
SOC: #<TCPSocket:0x682078>
~~~ DRbConn.open called
REMOTE_URI: nil
@mutex: #<Mutex:0x6d52a0 @locked=false, @waiting=[]>
CONN: nil

### DRbProtocol.open has been called
URI: nil
FIRST?: true
PROTOCOL:DRb::DRbTCPSocket
=== DRbTCPSocket.open has been called
URI: nil
Parsing uri...

### DRbProtocol.open has been called
URI: nil
FIRST?: false
PROTOCOL:DRb::DRbTCPSocket
=== DRbTCPSocket.open has been called
URI: nil
Parsing uri...
~~~ DRbConn.open called
REMOTE_URI: nil
@mutex: #<Mutex:0x6d52a0 @locked=false, @waiting=[]>
CONN: nil

### DRbProtocol.open has been called
URI: nil
FIRST?: true
PROTOCOL:DRb::DRbTCPSocket
=== DRbTCPSocket.open has been called
URI: nil
Parsing uri...

### DRbProtocol.open has been called
URI: nil
FIRST?: false
PROTOCOL:DRb::DRbTCPSocket
=== DRbTCPSocket.open has been called
URI: nil
Parsing uri...
/usr/local/lib/ruby/1.8/drb/drb.rb:739:in `open': can't parse uri:nil
(DRb::DRbConnError)