Re: [BLACKBOX] Debugging dll accessing programs

From: [at]} <Wojtek>
Date: Tue, 15 Mar 2011 10:43:10 -0400

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> Try to verify that the Main routine is invoked correctly.
> Does the dll need something like an initialization?
> Are you accessing it via an interface module?

My experience with using DLLs from under BB is a few years old, but I
still vividly remember mysterious crashes. I learned the hard way, that:
(1) The DLLs themselves were loading and calling many other DLLs. (2)
Those other DLLs were incorrectly installed. (3) There was no indication
of the latter.

In concrete termes, I was developing a data acquisition system using
National Instruments hardware and thus NI DLLs. It turned out that the
person, who installed NI, used inconsistent releases of that software from
CDs with different version numbers. The NI installer did not alert that
person, so he assumed that installation was successful. It turned out that
the DLL interfaces have changed between releases. The high-level DLLs were
calling functions which apparently did not exist anymore. The whole thing
was crashing.

The DLL interfaces have no consistency checks similar to BB. There was no
way of telling what was going on. After a ew weeks of struggling we
uninstalled the NI software entirly and we installed it on a clean machine
from a single set of CDs. This solved the problem.

I am telling this story to direct your attention away from BB and into the
underlying DLLs. If you have the source code, then you are in good shape.
If you do not, then you will need to read Microsoft pages, install some
debugging tools to investigate the DLL chain, etc. Remember that one DLL
is likely calling the whole lot of other DLLs.

Not sure if it is relevant to your case. I wish you good luck.

Wojtek

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Received on Tue Mar 15 2011 - 15:43:10 UTC