From: "Simon Kröger" <SimonKroeger@...>
Date: 2005-08-09T06:18:54+09:00
Subject: Re: Threading+TCPServer issues on Win32

Bill Atkins wrote:

> I'm having an issue with threading and TCP servers on Win32.  I've
> boiled down the issue to the following code:
> 
> -----
> 
> require 'socket'
> 
> t = Thread.new do
>   serv = TCPServer.new '', 344
>   sock = serv.accept
>   sock.puts "ok"
>   sock.close
>   serv.close
> end
> 
> puts "OK, enter text: "
> puts gets
> 
> -----
> 
> So with a server listening in the background, the program should
> accept one new request and respond with "ok".  In the meantime, it
> should be waiting for the user to enter text on STDIN.
> 
> If this program is running in a UNIX environment, I can telnet to port
> 344 and I'll be greeted with "ok" and the program will continue to
> wait for user input.  However, when I run the same code on Windows,
> the connection on port 344 opens (i.e. there is no connection refused
> error), but no text is received.  If I enter a word on the server's
> STDIN and hit enter, the server quits and the connection is severed,
> but the "ok" still doesn't get to the client.
> 
> I am quite possibly missing something obvious here, but I'm not sure
> what it is.  Any help would be appreciated.
> 

Hi Bill,

that's the same problem as

require 'timeout'
timeout(1){ puts gets }

this will never return (or throw the timeout exception) as
long as you do not hit a key.
Ruby has no native threads, it gets stuck on blocking system
calls.

I tried to circumvent the problem with Kernel#select, but for
some reason

select( [$stdin], nil, nil, 1.5 )

always returns immediately. Is there someone who can explain?

cheers

Simon