Re: Debugger for system problems?
"David Deley" <deleyd@gte.net> wrote in message
news:aX%Pl.63877$9J5.25553@newsfe13.iad...
Any suggestions on how to track down program cross contamination problems,
where one program gets messed up by the existence of two other completely
unrelated programs? Any system debuggers? I haven't had much luck with
that line mode debugger Microsoft offers.
For instance, the touch pad on my HP laptop will suddenly stop working,
but the mouse plugged into the USB port still works fine. I'm guessing
some other program or combination of programs is eventually messing up the
touch pad driver memory, somehow, I have no idea if it's even possible to
debug this type of problem.
Another example of program cross contamination I encountered awhile ago
was a listbox in my text editor would sometimes display garbage instead of
what it was supposed to. That problem only happened when I also had both
Logitech SetPont and Actual Window Minimizer installed.
(It was SetPoint 3.30 I recall. That was the latest available at the time,
and all earlier versions of SetPoint I could get also caused the same
problem. I tried a later version and it still caused the same problem. I
solved that just by getting rid of Logitech SetPoint and Actual Window
Minimizer.)
Which one actually caused the issue, SetPoint or AWM? I helped develop
SetPoint (in 2004). It uses a combination of hooks and KHAL (which is a
user-mode DLL that communicates to the Logitech driver using custom
"messages", I believe). I would think it would be AWM causing the listbox
garbage since SetPoint affects input devices and not the screen, whereas AWM
affects windows.
There are low level debuggers such as OllyDbg, WinDbg, etc. but I don't know
how to use them to track down garbage in a listbox. It is possible for a
3rd party app to inject and subclass a window so that it can put whatever
text it wants to inside it (including garbage). But it sounds like memory
corruption somehow.
[I thought VMS solved the problem of program cross contamination decades
ago. It was a multi-user machine. Impossible for one user to inadvertently
mess up what another user was doing. Messing with another user was only
possible if you changed mode to Kernel, and had the privileges to do so.
(And you couldn't make any mistakes in Kernel mode or the whole thing
crashed.) I thought Windows XP was a descendant of VMS. Really annoying
when I discover I've been spending hours debugging a perfectly good
program, the problem is cross contamination by some other completely
unrelated program.]
Well, if you want to have apps like SetPoint and AWM that change the
behavior of your system on a global basis (for all processes running),
obviously the OS needs to allow code to run that affects all processes, and
this could cause unpleasant side-effects. Especially Windows hooks and
drivers do affect processes on a global basis.
You can run Process Monitor to view the DLL's loaded into your process and
see if there are any from 3rd party packages like SetPoint and AWM which
might be causing issues. This won't detect drivers such as filter drivers
which also affect processes.
I guess what I'm saying is unfortunately with all our advanced knowledge of
Windows as developers, none of it really is enough to diagnose this issue,
and we are left with what every other Windows user needs to do: just
uninstall the crappy software. ;)
-- David