From: Armin Armbruster <aarmbruster@...>
Date: 2008-07-26T03:30:18+09:00
Subject: Re: Threads: Different behavior under Linux and Windows

Hi guys,

this problem has been costing me some nerves now. I've tried various 
things, including EventMachine, with no luck (maybe I did something 
wrong).

Anyhow, I finally gave up trying a direct approach and tried a 
sub-process/socket approach similar to what Ara suggested.
Here's something that finally works:

require 'socket'
require 'win32/process'

PORT_NUMBER = 12345

CHILD_PROC = 'ruby -e "' <<
          'sleep 0.1;' <<
          'csock = TCPSocket.new(\'localhost\',' << PORT_NUMBER.to_s << 
');' <<
          'loop{a = gets; csock.print a; exit if a =~ /^exit$/;}'

p = Process.create(:app_name => CHILD_PROC)
#create a green thread that counts every second, to prove that the 
parent process is not blocked
t = Thread.new{c = 0; loop{c+=1; puts c;sleep 1}}

l = TCPServer.new('localhost', PORT_NUMBER)
psock = l.accept and l.close
loop{ a = psock.gets; print "Got: #{a}"; exit if exit if a =~ /^exit$/;}

(Note: the example isn't very useful, all it's supposed to show is that 
the ticker thread is still running while the loop in the parent thread 
is blocking on the psock.gets).

I have to admit that I'm not very experienced with either windows 
programming or network programming, so while this works I still have 
some questions.

1. Both parent and child process run in the same console window. Who 
"owns" stdin, stdout and stderr? Is there a way that the child process 
could own stdin and the parent stdout and stderr?

2. Luis/Dan - you mentioned that Park Heesob has submitted a patch that 
should actually fix the original problem in MRI, but that there were 
some problems with it and therefore it had been reverted. Does anybody 
know whether the latest patchlevel of 1.8.6 (p115 I think) does have the 
problem fixed? If yes, can I download the patch in binary format (so far 
I've been using the One-click-installer, I have no experience with 
building ruby from source).

3. How does fxri circumvent this problem? I can start a ticker thread in 
fxri and it's happily ticking away. If I try the same thing in irb in a 
console, the ticker stalls until I type stuff.

Thanks,
Armin
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