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From: Alan Mackenzie <acm@muc.de>
To: Eli Zaretskii <eliz@gnu.org>
Cc: Daniel Colascione <dancol@dancol.org>, emacs-devel@gnu.org
Subject: Re: Help please! To track down GC trying to free an already freed object.
Date: Tue, 2 Apr 2019 20:46:53 +0000	[thread overview]
Message-ID: <20190402204653.GC25792@ACM> (raw)
In-Reply-To: <835zrwfc21.fsf@gnu.org>

Hello, Eli.

On Tue, Apr 02, 2019 at 22:21:26 +0300, Eli Zaretskii wrote:
> > Date: Tue, 2 Apr 2019 12:09:59 -0700
> > From: "Daniel Colascione" <dancol@dancol.org>
> > Cc: emacs-devel@gnu.org
> > 
> > rr is incredibly helpful for debugging this sort of problem. See
> > https://rr-project.org/. You can record an rr session containing the
> > crash, replay it, get to the crash, and then reverse-next, reverse-finish,
> > and reverse-continue your way through the GC, running it in reverse until
> > you find whatever it is that made mark_object on the dead object happen.

> GDB supports reverse execution as well, on some platforms.

On my GNU/Linux system, I tried to run 'reverse-next', and got the error
message:

    Target multi-thread does not support this command.

.  :-(  I suppose I could reconfigure without multi threading, but then
the bug (which is reproducible) probably wouldn't happen in the same
place.

-- 
Alan Mackenzie (Nuremberg, Germany).



  reply	other threads:[~2019-04-02 20:46 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-02 11:25 Help please! To track down GC trying to free an already freed object Alan Mackenzie
2019-04-02 15:04 ` Eli Zaretskii
2019-04-02 20:42   ` Alan Mackenzie
2019-04-03  4:43     ` Eli Zaretskii
2019-04-04 18:57       ` Alan Mackenzie
2019-04-02 19:09 ` Daniel Colascione
2019-04-02 19:21   ` Eli Zaretskii
2019-04-02 20:46     ` Alan Mackenzie [this message]
2019-04-02 21:03       ` Daniel Colascione
2019-04-03  4:39       ` Eli Zaretskii
2019-04-03 10:01         ` Alan Mackenzie
2019-04-03 10:12           ` Eli Zaretskii
2019-04-03 15:23           ` Paul Eggert
2019-04-02 20:24   ` Alan Mackenzie
2019-04-02 20:33     ` Daniel Colascione
2019-04-02 21:00       ` Alan Mackenzie
2019-04-05  4:49         ` Alex
2019-04-05  8:26           ` Alan Mackenzie
2019-04-05 17:05             ` Comparing symbol-with-position using eq (was: Help please! To track down GC trying to free an already freed object.) Alex
2019-04-05 18:21               ` Comparing symbol-with-position using eq Alan Mackenzie
2019-04-05 20:18                 ` Daniel Colascione
2019-04-05 21:54                   ` Alan Mackenzie
2019-04-05 22:50                     ` Paul Eggert
2019-04-06 12:23                     ` Clément Pit-Claudel

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