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From: Linas Vepstas <linasvepstas@gmail.com>
To: 27234@debbugs.gnu.org
Subject: bug#27234: Followup.
Date: Sat, 9 Sep 2017 15:44:11 -0500	[thread overview]
Message-ID: <CAHrUA37zT6FU606vJhDD250nByzpkmj9_DBVvNgjXE3PAdf1sg@mail.gmail.com> (raw)
In-Reply-To: <CAHrUA361VtW9ZOgEbxTYsDi3K7WY4YVaGA=YAK3VQKSVs8Bc_g@mail.gmail.com>

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The original bug report failed to explain how to trigger the bug.  I think
I know of a simple way to trigger the bug, but have not yet created the
simple test-case.  I believe that the bug can be triggered like so:

Create some medium-sized "random" (arbitrary) snippet of guile code. Send
it to the guile repl server.  Do it again and again, as fast as possible.
The bug will trigger.

By "arbitary/random" I mean some code that is simple but non-repeating:
say, concatenate some random strings, count the number of letters in them,
take the square root -- just do assorted, non-repeating computations that
force the REPL to evaluate some new blob of scheme code every time.

Now, once out of every 5 or 50 times, introduce a bug in the scheme code,
causing the REPL to throw an exception.  Using ut8 strings might also be a
required ingredient.

I believe that this will trigger the bug. I believe that the bug is some
unprotected section in the guile interpreter, and a race condition clobbers
the guile stack(s) and it all goes downhill from here.

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      reply	other threads:[~2017-09-09 20:44 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-04 14:57 bug#27234: Hang in GC, inf loop while walking frame pointers Linas Vepstas
2017-09-09 20:44 ` Linas Vepstas [this message]

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