Stream: Mirror: Isabelle Users Mailing List

Topic: [isabelle] Isabelle2022 leaking minisat processes


view this post on Zulip Email Gateway (Nov 04 2022 at 16:11):

From: "C. Diekmann" <diekmann@net.in.tum.de>
Howdy,

when developing new theories in Isabelle 2022, I noticed that after a while
I have some minisat processes running at 100% in the background all the
time. The more I develop, the more such processes I see. They don't seem to
belong to anything useful. I can kill them and everything continues to work.
Is it just me or is Isabelle 2022 leaking minisat processes? I think this
may be new behavior since 2022.
I'm a heavy user of try and sledgehammer.

Cheers,
Cornelius

view this post on Zulip Email Gateway (Nov 05 2022 at 11:00):

From: Makarius <makarius@sketis.net>
Minisat belongs to Nitpick. We need to investigate what is really going on:
there have been some changes concerning Minisat in the past few releases.

What is your OS? Which version?

Makarius

view this post on Zulip Email Gateway (Nov 05 2022 at 11:07):

From: "C. Diekmann" <diekmann@net.in.tum.de>
Ubuntu 22.04 x64

I'm also using nitpick directly quite often, but when I stopped using
try, I had the feeling I no longer had minisat processes leaking.

Unfortunately, I don't know how to reproduce this. Is anyone else seeing
this behavior?

view this post on Zulip Email Gateway (Nov 05 2022 at 13:04):

From: "C. Diekmann" <diekmann@net.in.tum.de>
I think I managed to reproduce the scenario:

<goog_2094504539>
https://github.com/diekmann/kant/blob/2b490f947c1bf5c359ff42d971844314bc8295a6/Formal/BeispielSteuern.thy#L157
Unfortunately, this is not a minimal example :-(

My system: Ubuntu 22.04.1 LTS x86_64
Isabelle 2022 from the website.
The example reproduces on my laptop natively and on a different machine in
VirtualBox.

Once nitpick has finished, I still see minisat processes (3 on my virtual
machine, 4 on my laptop), consuming 100% cpu each.
On my system, they are shown as
Isabelle2022/contrib/minisat-2.2.1-1/x86_64-linux/minisat
/tmp/tmp7721537082318768953cnf /tmp/tmp12073518872663065644out

Nitpick displays:

Warning: The conjecture either trivially holds for the given scopes or lies
outside Nitpick's supported fragment; only
potentially spurious counterexamples may be found
Nitpick ran out of time after checking 5 of 10 scopes

Even after some waiting, the minisat processes don't terminate, consuming
cpu.

A pkill minisat does not seem to cause any Isabelle instability.

I hope this reproduces a scenario where minisat processes are leaked.

view this post on Zulip Email Gateway (Nov 06 2022 at 01:22):

From: Yutaka Nagashima <united.reasoning@gmail.com>
Hi Cornelius,

This happened to me as well when I was using nitpick heavily as a sub-tool
on Windows 10 x64.
I saw minisats running even after I killed Isabelle 2021-1, so probably the
problem is not that new.

Unfortunately, I do not have a small example I can share to replicate the
problem.

Regards,
Yutaka

view this post on Zulip Email Gateway (Nov 10 2022 at 10:51):

From: "\"Blanchette, J.C. (Jasmin Christian)\"" <cl-isabelle-users@lists.cam.ac.uk>
Hi all,

Thanks for the reports. I wasn't aware that Nitpick was leaking MiniSat processes. I'm surprised these processes go on once Kodkod is done running. The fix seems simple: Pass a timeout to MiniSat, which it should honor. I've now done so in the development version of Isabelle.

Cheers,
Jasmin


Last updated: Apr 27 2024 at 04:17 UTC