Cees,

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I've been experiencing UI hangups ever since I started working with
Squeak-at-the-backend (Seaside, my current P2P stuff, even various Swiki
incarnations I think) - the symptom is always the same: Squeak does not
respond to mouse&keyboard anymore, but the networkings bits still work.
============================

It has been a while ago now, but I had a problem that would describe as
Mprphic locking up but the VM still working.  In particular, I could
interact with the VM system menu (windows) commands to dump the call
stack on the current thread.


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I now have an image with a severe case of this - it'll hangup in as
little
as 10 minutes... So I'm getting tired of this, I want to solve this for
once and for all :)

So, my questions:
- What are the possible causes?
- What is a debugging strategy to find out exactly where it goes wrong?
============================

In all honesty, I cannot answer your question.  In my case, it was
apparently a case of inadequate mutual exclusion.  I made a critical
section bigger, and was no longer able to reproduce the lockup.  I no
longer recall the details, but it was driven by looking at callstacks
from other than the active process/thread.

So, here is what I recommend: modify the dump call stack command to dump
all non-dead processes, not merely the active one.  I did it by
compiling my own VM.  I did what I could at the time to make the changes
available, but got the distinct sense of shouting into a canyon with no
echo.  I might be able to find what I did to make it work; let me know
if you have interest; better still, let me know if there is collective
interest in making what IMHO would be a very useful change to the VM.

Bill



Wilhelm K. Schwab, Ph.D.
University of Florida
Department of Anesthesiology
PO Box 100254
Gainesville, FL 32610-0254

Email: bills at anest4.anest.ufl.edu
Tel: (352) 846-1285
FAX: (352) 392-7029