Email Gateway (Aug 19 2022 at 16:54): Email Gateway (Aug 19 2022 at 16:54):From: Joachim Breitner <breitner@kit.edu>
Hi,
I just had a greyout followed, after a while, by this message:
Welcome to Isabelle/HOLCF-Nominal2 (Isabelle2014: August 2014)
poly: gc_mark_phase.cpp:439: virtual void MTGCProcessMarkPointers::ScanAddressesInObject(PolyObject, POLYUNSIGNED): Assertion `baseAddr > (PolyWord)obj && baseAddr < ((PolyWord*)obj)+length' failed.
Malformed message:
bad chunk (unexpected EOF after 136 of 618 bytes)
message_output terminated
/opt/isabelle/Isabelle2014/lib/scripts/run-polyml-5.5.2: Zeile 84: 7181 Abgebrochen "$POLY" -q -i $ML_OPTIONS --eval "$(perl "$ISABELLE_HOME/lib/scripts/recode.pl" "$MLTEXT")" --error-exit < /dev/null
standard_error terminated
standard_output terminated
process terminated
command_input terminated
process_manager terminated
Return code: 134
This happened during a refactoring phase, where I have a number of
„target“ theories ticked in the theory panel, which obviously puts some
strain on the system. I was disabling and enabling the global
„Continuous checking“ parameter before, which might be related.
This is a Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz machine with 4 cores,
8GB or RAM.
Greetings,
Joachim
signature.asc
Email Gateway (Aug 19 2022 at 16:55):From: Peter Lammich <lammich@in.tum.de>
For me it looks like there is some bug in the PolyML garbage collector,
which is likely to be triggered under heavy parallel load. David??
I get this assertion sometimes (3 times in the last month) if I open a
theory that depends on a whole bunch of new theories.
My machine is
Intel(R) Core(TM) i7-2720QM CPU @ 2.20GHz with 4 cores (i.e. 8 cores
with hyperthreading), with 8GB of RAM
Email Gateway (Aug 19 2022 at 16:56):From: Makarius <makarius@sketis.net>
On Wed, 14 Jan 2015, Joachim Breitner wrote:
Welcome to Isabelle/HOLCF-Nominal2 (Isabelle2014: August 2014)
poly: gc_mark_phase.cpp:439: virtual void MTGCProcessMarkPointers::ScanAddressesInObject(PolyObject, POLYUNSIGNED): Assertion `baseAddr > (PolyWord)obj && baseAddr < ((PolyWord*)obj)+length' failed.Malformed message:
bad chunk (unexpected EOF after 136 of 618 bytes)
message_output terminated
/opt/isabelle/Isabelle2014/lib/scripts/run-polyml-5.5.2: Zeile 84: 7181 Abgebrochen "$POLY" -q -i $ML_OPTIONS --eval "$(perl "$ISABELLE_HOME/lib/scripts/recode.pl" "$MLTEXT")" --error-exit < /dev/null
See also this thread (and many clones of it):
https://lists.cam.ac.uk/pipermail/cl-isabelle-users/2014-December/msg00097.html
David Matthews might eventually find a way around it.
Apart from that, it should be noted that non-trivial Isabelle applications
need non-trivial hardware resources, according to 2015, not 2010 like
this:
This is a Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz machine with 4 cores,
8GB or RAM.
Time is running out for the 32bit address model, and for 64bit life starts
at 16 GB, or a bit more. 32 GB is cheap for normal workstations today.
Makarius
Email Gateway (Aug 19 2022 at 16:57):From: David Matthews <dm@prolingua.co.uk>
The garbage collector has got increasingly complex particularly now that
it has been parallellised. It relies on various properties of the
underlying memory to avoid too much locking. Bugs in the GC can result
in the memory getting messed up leading to random errors and segfaults
at some indeterminate point in the future. To try and capture errors
earlier rather than later there are many assertion checks that check for
consistency.
This particular assertion fault seems to happen under heavy load. I've
been aware of it but I've never been able to reproduce it myself.
Without a core dump with the debugging symbols included it's virtually
impossible to see what is happening. The fault itself indicates that a
value is not what it should be but not how it got there. I was hoping
that perhaps there would be an example that would demonstrate the fault
sufficiently consistently that I would be able to reproduce it.
The fault, though, is in a piece of code that was added to deal with
large vectors/arrays which were previously very inefficient. It would
be possible to take that out. I think the best solution is to try and
make some effort to try and fix the fault and if that fails to remove
the code.
David
Email Gateway (Aug 19 2022 at 16:58):From: Peter Lammich <lammich@in.tum.de>
How to make PolyML Isabelle/jEdit produce such a core dump with
debugging symbols?
Email Gateway (Aug 19 2022 at 16:58):From: Makarius <makarius@sketis.net>
There should be nothing specific about Isabelle/jEdit here.
You just compile Poly/ML "as usual", e.g. as explained in the README of
the polyml component that is used for Isabelle. E.g. polyml-5.5.2-1 for
Isabelle2014. The build script accepts arguments to ./configure such as
--enable-debug.
You can probably compile it in-place of the existing component, and then
restart. If something is messed up, you just take a fresh copy from
http://isabelle.in.tum.de/components/.
Makarius
Last updated: Nov 21 2024 at 12:39 UTC