colin@pdn.UUCP (Colin Kendall) (05/27/88)
In the April edition of HOOPLA, Ward Cunningham of Tektronix
describes an elegant error handler, and includes the methods
used to implement it in Tektronix LOS Smalltalk. We are trying
to implement it in ParcPlace VI2.2, with no success.
The article shows the instance variable 'errorHandler' added to
class Process. When we try to do this, the image dies (no keyboard
or mouse response) and a core image is written.
Suspecting that this had to do with the obsoleting or updating
of the active process, I commented out the "self updateInstancesFrom:
oldClass" in
ClassDescription>validateFrom:in:instanceVariableNames:methods:; this
helped a little, inasmuch as it produced some Transcript error
messages before core dumping, to wit:
Message not understood: priority
ProcessorScheduler>activePriority
BlockContext>newProcess
ControlManager>activeController:
Type s for more stack, anything else restarts...
Unfortunately typing s or anything else had no effect.
We have a call in to ParcPlace about this, but my experience with
them is that they make excellent software but their customer
service is effectively non-existent.
Has anyone implemented this stuff? Any help would be appreciated.
If I get it working I'll post the solution, if any interest is
expressed.
--
Colin Kendall Paradyne Corporation
{gatech,akgua}!usfvax2!pdn!colin Mail stop LF-207
Phone: (813) 530-8697 8550 Ulmerton Road, PO Box 2826
Largo, FL 33294-2826hmm@laura.UUCP (Hans-Martin Mosner) (05/30/88)
Andreas Guendel (guendel@unido.uucp) and myself have done something similar
(adding an inst var to Process). The way we did it involved creating a
class NewProcess with the new inst var, then changing all references to Process
into NewProcess, becoming all Processes into NewProcesses and then renaming
NewProcess. If this sounds messy, ... it is :-)
If you can't get it to work, try getting a better description of the procedure
from Andreas, as I can't remember it exactly.
Hans-Martin
--
Hans-Martin Mosner | Don't tell Borland about Smalltalk - |
hmm@unido.{uucp,bitnet} | they might invent Turbo Smalltalk ! |
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Disclaimer: Turbo Smalltalk may already be a trademark of Borland...