[Twisted-Python] Twisted 2.0 prerelease (close!!)

glyph at divmod.com glyph at divmod.com
Thu Mar 10 01:35:35 EST 2005

On Thu, 10 Mar 2005 01:18:48 -0500, James Y Knight <foom at fuhm.net> wrote:
> On Mar 10, 2005, at 12:25 AM, Stephen Waterbury wrote:
> > 2005/03/09 16:53 EST [HTTPChannel,2,] 
> > /usr/lib/python2.3/site-packages/twisted/internet/tcp.py:216: 
> > exceptions.UserWarning: SSL connection shutdown possibly unreliable, 
> > please upgrade to ver 0.XX
> I think I'll just remove that warning. It's warning about a situation 
> which I believe *may* never actually be able to happen: during final 
> connection shutdown, the socket is reported writable, but OpenSSL is 
> for some reason unable to write the final packet. I looked through the 
> code, and while I wasn't able to convince myself it couldn't happen, I 
> did convince myself that it was rather unlikely, at least. If that does 
> happen somehow, (and you aren't using "0.XX" of pyOpenSSL), twisted has 
> no way of ever finding out. Thus the warning telling you to upgrade.

In fact I believe this situation can and does happen: if the other side of the connection suddenly and totally goes away (and is also filtering all ICMP including port-unreachable), the connection will hang forever.

This looks like another use-case for a 'killConnection' method...

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