Re: Prevent freezing when having bad connection?

[Ted Zlatanov <tzz@lifelogs.com>]

On Wed, 22 Feb 2012 03:07:55 +0100 Michael Heerdegen <michael_heerdegen@web.de> wrote: 

MH> Lars Ingebrigtsen <larsi@gnus.org> writes:
>> > strace -fp just prints
>> >
>> > [pid 22477] recv(12, 0xb73cfa0, 5, 0) = -1 EAGAIN (Resource
>> > temporarily unavailable)
>> 
>> This is a different problem.  The bug I fixed was related to writing,
>> not reading.

MH> I'll look for the socket when I'm at home again.

MH> BTW, when I got that, I simply pulled out my USB stick, so that the
MH> connection was still active, but with a zera data rate.  I hope that's a
MH> good way to mimic a "bad connection" (or should I better put a metallic
MH> coffee tin around the stick?).

I have noticed hung NNTP connections that manifest the same way.
Usually `C-g' will fix it but it's very annoying because it looks as if
it's waiting for the remote server and you sit for 10-15 seconds before
you realize it's hung.  `strace -p' shows read() returning EAGAIN over
and over.  This is hard to simulate though, I have to open the
connection and wait 10 minutes to be sure it will hang.

Lars, I thought we were setting a heartbeat on the TCP connections in
Emacs?  Is Emacs supposed to notice that the NNTP connection is hung?
This is not encrypted with GnuTLS so I think it's an Emacs-level issue.

Ted