From: Guillaume Marcais <guslist@...>
Date: 2006-01-24T14:33:53+09:00
Subject: Buffered IO and UDPSocket

This one is driving me nuts! What causes and IO object (more 
specifically a UDPSocket here, bound to port 1025) to become "buffered"?

When I do simple test case in irb with such a socket, I can call 
#recvfrom on it with no problem. In my actual server, I get the error: 
"`recvfrom': recv for buffered IO (IOError)". I can't figure out why.

I payed attention that no threads are created, I do a select on this 
socket (and others) to check for read readiness before calling #recvfrom.

So what made the socket suddenly buffered so that #recv becomes illegal? 
How can I check the buffered status of an IO? Can I revert it from 
buffered to unbuffered?

It seems that I could get around this condition with #readpartial. But 
this method is not avaible in 1.8.2. This code will need to run on 
Windows and I rely on the one click installer...

Could someone shed some light on this "buffered" issue? It confuses the 
hell out of me and the Google responses didn't enlighten me.

Guillaume.