From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2001-02-23T06:10:03+09:00
Subject: [ruby-talk:11347] Re: dRuby problem with Threads(still need solution - Threads problem?)

OK, I'm gonna try posting this for the third time...  could be duplicates, but it 
doesn't seem to want to go.

In article <Xns905072CA26D28wyshelblingch@130.133.1.4>,
Clemens Wyss <wys@helbling.ch> wrote:
>ptkwt@shell1.aracnet.com (Phil Tomson) wrote in
><Sb3l6.739$Vf.26882@typhoon.aracnet.com>: 
>
>>This is a strange one - then again It's about 11:20PM so everything is
>>looking strange.
>>
>...for me it's 11:20am
>
>I let the server and the client run on the same W2K-box.
>This is the slightly modified client code:
>#### client
>require 'drb'
>machine = "localhost"
>command = "this is the command"
>DRb.start_service()
>drbObj  = DRbObject.new(nil, "druby://#{machine}:9000")
>def threaded(drbObj, command)
>  thread = Thread.new() {
>    p "start"
>    drbObj.eval_it(command)
>    p "end"
>  } #thread   
>  thread.join() # Phil you *forgot* this one!

Actually, no I didn't forget this - I don't want it.  Adding thread.join here 
effectively blocks so that execution doesn't continue till after the thread 
finishes.  This is a distributed app that sends commands to several machines 
running various Unix and Windows OS's.  The intent is for it to send a command and 
then go look for the next available machine (not to wait around for the current 
target to finish).


>end
>#DRb.stop_service()
>def single(drbObj, command)
>  p "start"
>  drbObj.eval_it(command)
>  p "end"
>end
>
>single(drbObj, command)
>threaded(drbObj, command)
>#####
>
>Note the thread.join()-line. Looks like windows terminates immediately
>(i.e. tearing down your thread -> this could be the reason for your error
>messages!) without the join-call. Now calling my code sometimes (not
>allways though) produces the following error on the client side!: 
>
>"/cygdrive/d/ruby/lib/ruby/site_ruby/1.6/drb/drb.rb:189:in `open':
>Invalid argument - "connect(2)" (Errno::EINVAL) 
>        from E:\drb_cl.rb:12:in `join'
>        from E:\drb_cl.rb:12:in `threaded'
>        from E:\drb_cl.rb:22
>"
>
>Looks like there is still a *slight* problem, just a different one.
>Clemens
>
I didn't see that problem when I added the join (just to try it out).

So my question still remains - why does the dRuby server care if a method was 
called from the client's main thread of execution or from another spawned thread?


It works from Linux -> Linux, but not from Linux -> Windows (server running on 
Windows).  I believe it used to work when all my machines were running 1.6.1 with 
drb 1.2.2 (now we're all at 1.6.2 with drb 1.3)

Phil