Squeak lockup
Bill Schwab
schwabw at sprynet.com
Wed Jun 5 03:50:41 UTC 2002
Andreas,
> The short version is that I'm very interested in seeing how one
> debugs such things in Squeak.
It is very hard to do this. Partly because you need low-level VM
tools
to look into some of these issues. In particular if they only happen
on
some machines it means that some assertion of the VM about its
hosting
platform is wrong. And that means you need to go into it very low-
level.
There are some features that might help (I added for instance the
ability to list all socket state in order to find some of the socket
related problems) but this doesn't replace a debugger. Since all of
the
VM maintainers test quite heavily across all (available) flavours of
OSes it also means that the code "ought to work" as it is.
-------------------------
I'm not quite as convinced as you that my code is innocent and the
VM is to blame :) Either way, the machine in question is a
challenge. It's a slow machine (P200) with an ancient Win95
installation, but some seriously nice components, especially for
when it was built. Considering just my MIDI application agenda,
the plan was to use the machine to see if I could establish
communication with my digiital piano and do some interactive stuff
in Squeak. It works, modulo the lockups, so I'm now slowly
juggling hardware to put something faster on a wheeled cart - the
UPS arrived today. I haven't quite decided which machine to
mobilize, but, worst case it will be a P2-400 with 320MB of RAM.
As far as debugging tools, the socket thing sounds great. Squeak
shows what it was doing at the time of a crash; I can't really
comment on the usefulness of the result because I haven't needed
it for any of my code.
The lockup scenario seems to be unaddressed though. Would it
be possible to generate a call stack for each Process, perhaps by
command on the system menu? In my lockup, the VM appears to
still be responsive, so it would nice to get some idea of what the
Smalltalk code is trying to do. One thing I'm considering is that I
botched the morphic side of the project, causing either deadlock or
running out of space.
Making a long story short, I'm considering Squeak as my escape
vehicle should I need to leave Windows. There are things that I
would change about Squeak, but, so far, I'm finding that I would be
able to work with it. The next question is whether it can handle the
kinds of things I'd ask of it. To find out, I'm doing some things with
MIDI and 3D graphics. Neither project pays any bills (yet
anyway<g>), but they are non-trivial. One thing that I'm missing so
far is networking. My planned "update server" lost some steam
because I had to create most of the functionality in Dolphin as part
of my Win2k rollout.
> To date, I've gotten crash dumps
> >from it by enabling 3D hardware acceleration on a particular
> machine;
That machine wouldn't use a graphics card which is based on a
RIVA TNT
chip on Win98, would it?! I just got a totally weird crash report from
such a configuration but since I don't have access to it it's almost
impossible to do remote debugging.
--------------------
It's listed in the control panel as ATI 3D Rage Pro (atir) - I'm not
sure what that means re the chipset you've listed, but, I can look
into it if some kind soul doesn't beat me to it. The machine is
running Win98.
The documentation that came with the card is not at all matching
up with the information reported by the control panel. If necessary,
I can always open the box and look at the chips.
Bill
Wilhelm K. Schwab, Ph.D.
bills at anest4.anest.ufl.edu
(352) 846-1285
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