From: Stefan Monnier <monnier@iro.umontreal.ca>
To: joakim@verona.se
Cc: ding@gnus.org, emacs-devel@gnu.org
Subject: Re: Blocking call to accept-process-output with quit inhibited!! [11 times]
Date: Tue, 07 Sep 2010 12:38:33 +0200 [thread overview]
Message-ID: <jwvmxrtdeox.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <m3tym2f2tx.fsf@verona.se> (joakim@verona.se's message of "Tue, 07 Sep 2010 09:08:26 +0200")
>>> In Emacs 24, I get this message the first time I enter a Gnus group.
>>> What does it mean, and what can I do to make it go away?
>> It means just that: accept-process-output is called in a way that can
>> block (e.g. because some remote host doesn't respond) wit inhibit0quit
>> set to a non-nil value, which means that Emacs may end up frozen (with
>> no way to wake it up) for as long as the remote machine decides not
>> to answer.
>> IOW, maybe there should be a (with-local-quit ...) somewhere so that the
>> user can C-g out of such a state (or the call should have a timeout, or
>> inhibit-quit should not be set, ...).
> I get bitten by this quite a lot, since I'm often on a flaky 3g
> line. When the link goes down, and some Emacs socket is still up, Emacs
> freezes. This is quite annoying.
Emacs should not freeze in such a case. IIUC most cases where this
happen are Elisp bugs (typically a missing with-local-quit or something
like that), tho there are a few cases where it's a problem at the
C level (IIRC, one such is during hostname lookup, but I don't know of
any such case once the TCP connection is established).
> I suppose that the hard blocking is there to prevent data loss or
> whatever, but having to kill -9 Emacs results in worse dataloss.
No, usually it's there because the Elisp coder is not aware of the risk
(e.g. he doesn't realize his code will be run with inhibit-quit set,
probably because he doesn't realize that this is set whenever we run
process filters, process sentinels, post-command-hook, jit-lock,
timers, and a handful other cases).
Stefan
next prev parent reply other threads:[~2010-09-07 10:38 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <m37hiya7na.fsf@quimbies.gnus.org>
2010-09-06 21:41 ` Stefan Monnier
2010-09-06 21:48 ` Lars Magne Ingebrigtsen
2010-09-07 7:08 ` joakim
2010-09-07 10:38 ` Stefan Monnier [this message]
2010-09-07 11:11 ` joakim
2010-09-07 11:53 ` Lars Magne Ingebrigtsen
2010-09-08 8:10 ` Stefan Monnier
2010-09-07 18:33 ` Tom Tromey
2010-09-08 8:12 ` Stefan Monnier
2010-09-07 11:54 ` Lars Magne Ingebrigtsen
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