Email Gateway (Aug 19 2022 at 10:57): Email Gateway (Aug 19 2022 at 10:57):From: Joachim Breitner <breitner@kit.edu>
Hi,
here at Karlsruhe we are offering a practical Course on Isabelle which
began last week and we were badly surprised that Isabelle/jEdit 2013 had
severe issues on the machines in the student’s pool room: A short while
into editing the highlighting (errors and the light blue) and the output
window are no longer updated.
We could reproduce it most easily by writing, say,
theory Scratch imports Main begin lemma "foobar"
and then changing "lemma" to "le mma" and back in very rapid succession.
The machines in question are Fedora 18 systems, 64 bit, 4GB RAM, no swap
and the file systems on NFS. We also reproduced it on machines with more
RAM and on machien with the 32 bit libraries installed in addition. We
cannot reproduce it on our own workstations, though.
It seems it is happening more easily on slower machine. Maybe some race
condition?
We are at a loss here – any idea how to get it working more reliable?
Thanks,
Joachim
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Email Gateway (Aug 19 2022 at 10:57):From: Lars Noschinski <noschinl@in.tum.de>
I occasionally had similar problems but did not manage to produce a
reproducible example yet. However, I managed to get the system back to
working by hitting the "Cancel' button in the "Theories" window a few times.
If I remember correctly, the problem occurred often when editing a proof
which was followed by a "lemma (in LOC)" where LOC was a reasonably big
locale from HOL-Algebra.
This occurred both with Isabelle 2013 and a recent Isabelle development
snapshot. Debian with a 64-bit Isabelle, 6GB RAM, Core 2 Duo and a Gnome
3 desktop.
-- Lars
Email Gateway (Aug 19 2022 at 10:57):From: Denis Lohner <denis.lohner@kit.edu>
Unfortunately, hitting "Cancel" doesn't work here at Karlsruhe. However,
in the student's computer pool hitting "Check" while a large theory file
is being processed, seems to reliabely result in the same freeze of the
Output panel.
As there is no error message in the Output panel or at the command line,
what are our options to investigate the problem? Is there an option to
log the communication between jEdit and the isabelle process? Would this
information help to find the cause?
Thanks,
Denis
Email Gateway (Aug 19 2022 at 11:05):From: Makarius <makarius@sketis.net>
The "Protocol" panel in Isabelle/jEdit gives a full transcript of the two
processes communicating, although that slows down things considerably, and
usually makes such non-deterministic problems disappear.
There have been reports about several such real-time reactivity problems
in the past few months, but so far very few concrete hints of the actual
reasons. Problems with Fedora 18 in particular had been reported before,
but this does not say much -- recent Linux distributions all tend towards
instabilities that were not there 1 or 2 years ago.
In the next round of refinements of Isabelle/Scala and Isabelle/jEdit, I
will be more defensive in the use of certain Java 7 GUI / window popup
features, and also in the use of Scala actors. There are reasons to
believe that these basic building blocks of the interactive framework are
not 100% reliable.
Apart from that, any more concrete observation where things don't work in
Isabelle2013 will be treated with the usual scrutiny.
Makarius
Last updated: Nov 21 2024 at 12:39 UTC