From: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
To: emacs-devel@gnu.org
Subject: Re: block_input for some APIs
Date: Tue, 13 Dec 2016 09:13:40 +0900 [thread overview]
Message-ID: <wl1sxc65zf.wl%mituharu@math.s.chiba-u.ac.jp> (raw)
In-Reply-To: <jwv1sxcrfcj.fsf-monnier+gmane.emacs.devel@gnu.org>
>>>>> On Mon, 12 Dec 2016 16:48:53 -0500, Stefan Monnier <monnier@iro.umontreal.ca> said:
>>> Does anyone remember why we block input around calls to functions like
>>> getpwnam or tzset or fwrite?
>> I think this dates back to when C-g and/or other handlers called
>> longjmp.
> I'm not completely sure, but my own impression is that this dates back
> to before SYNC_INPUT, i.e. with input became available, we'd get an IO
> signal and in the handler we'd run a whole bunch of code, since
> reentrance was a big issue. Nowadays we delay this async processing to
> the next QUIT so there's no re-entrance issue any more.
I added some of them around early 2007, when SYNC_INPUT was not used
by default. These functions call malloc etc. internally (at least on
Darwin), so it was not safe to call read_socket_hook, which also calls
malloc etc., from SIGIO/SIGALRM handler while processing getpwnam etc.
YAMAMOTO Mitsuharu
mituharu@math.s.chiba-u.ac.jp
next prev parent reply other threads:[~2016-12-13 0:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-12 18:01 block_input for some APIs Eli Zaretskii
2016-12-12 21:08 ` Paul Eggert
2016-12-12 21:48 ` Stefan Monnier
2016-12-12 21:53 ` Daniel Colascione
2016-12-13 3:46 ` Eli Zaretskii
2016-12-13 0:13 ` YAMAMOTO Mitsuharu [this message]
2016-12-13 3:43 ` Eli Zaretskii
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