git.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: John Cai via GitGitGadget <gitgitgadget@gmail.com>,
	git@vger.kernel.org, John Cai <johncai86@gmail.com>
Subject: Re: [PATCH] tmp-objdir: do not opendir() when handling a signal
Date: Tue, 27 Sep 2022 09:50:42 -0700	[thread overview]
Message-ID: <xmqqedvw7od9.fsf@gitster.g> (raw)
In-Reply-To: <YzLiI1HZeBszsIJq@coredump.intra.peff.net> (Jeff King's message of "Tue, 27 Sep 2022 07:44:35 -0400")

Jeff King <peff@peff.net> writes:

> So all of that makes me think we should not add a new flag here, but
> instead just avoid calling the function entirely from
> tmp_objdir_destroy_1().

Thanks.  I missed that undefined access to errno that breaks the
intention of the patch.

> But then we can observe that tmp_objdir_destroy_1() is basically doing
> nothing if on_signal is set. So there is really no point in setting up
> the signal handler at all. We should just set up the atexit() handler.
> I.e., something like:
>
> diff --git a/tmp-objdir.c b/tmp-objdir.c
> index a8be92bca1..10549e95db 100644
> --- a/tmp-objdir.c
> +++ b/tmp-objdir.c
> @@ -169,7 +169,6 @@ struct tmp_objdir *tmp_objdir_create(const char *prefix)
>  	the_tmp_objdir = t;
>  	if (!installed_handlers) {
>  		atexit(remove_tmp_objdir);
> -		sigchain_push_common(remove_tmp_objdir_on_signal);
>  		installed_handlers++;
>  	}
>  
>
> with the commit message explaining that we can't do the cleanup in a
> portable and signal-safe way, so we just punt on the whole concept.
>
> There's also some minor cleanup we could do elsewhere to drop the
> "on_signal" argument (which can come as part of the same patch, or on
> top).

;-)  I like the simplification.

  parent reply	other threads:[~2022-09-27 16:52 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-26 23:53 [PATCH] tmp-objdir: do not opendir() when handling a signal John Cai via GitGitGadget
2022-09-27  0:18 ` Taylor Blau
2022-09-27 11:48   ` Jeff King
2022-09-27  1:39 ` Junio C Hamano
2022-09-27  9:18 ` Phillip Wood
2022-09-27 11:44 ` Jeff King
2022-09-27 13:50   ` John Cai
2022-09-27 19:03     ` Jeff King
2022-09-27 16:50   ` Junio C Hamano [this message]
2022-09-27 19:19 ` [PATCH v2] tmp-objdir: skip clean up " John Cai via GitGitGadget
2022-09-27 19:38   ` Jeff King
2022-09-27 20:00     ` Jeff King
2022-09-28 14:55   ` [PATCH v3] " John Cai via GitGitGadget
2022-09-28 15:38     ` Ævar Arnfjörð Bjarmason
2022-09-30 20:47     ` [PATCH v4] " John Cai via GitGitGadget
2022-10-03  8:52       ` Jeff King
2022-10-20 11:58 ` Another possible instance of async-signal-safe opendir path callstack? (Was: [PATCH] tmp-objdir: do not opendir() when handling a signal) Jan Pokorný
2022-10-20 18:21   ` Jeff King

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=xmqqedvw7od9.fsf@gitster.g \
    --to=gitster@pobox.com \
    --cc=git@vger.kernel.org \
    --cc=gitgitgadget@gmail.com \
    --cc=johncai86@gmail.com \
    --cc=peff@peff.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).