[python-win32] Dr. Watson woes with ADO, mysql

[Mark Hammond]

> I've spent the last year writing an ORM in Python which I'm reasonably
> pleased with. But I have a recent problem: I can't seem to migrate
> tables from Microsoft Access (using ADO) to MySQL (using MySQLdb)
> without a crash. But, don't let the context fool you: when it 
> crashes, I
> don't think I'm doing *anything* with the ADO connection, and 
> I actually
> get the same crash when using Postgres instead of MySQL.
> 
> I'm not a Windows guru by any means, but I have noticed a pattern:
> throughout my (many, naive) code changes to try to avoid the 
> crash, the
> same functions keep popping up in drwtsn32.log:
> 
> function: PyComplex_AsCComplex
> function: NtWaitForSingleObject (multiple times)
> function: NtWaitForMultipleObjects
> function: ZwReplyWaitReceivePortEx
> function: NtDelayExecution
> function: ScrollDC

All except the first and last are quite usual.  I'm not sure where ScrollDC
has come from - are you using this from a GUI?

> 
> ...where PyComplex_AsCComplex is the first one listed, and (if I'm
> reading MSDN correctly) is therefore the function "where the fault
> occurred".
> 
> So the question is, what's the next step in tracking down the bug?
> PyComplex_AsCComplex is a pretty simple function. Or am I way off-base
> and should be looking elsewhere?

If a GUI is involved, you should try and make sure you are living within its
thread constraints.  Its possible to cause a crash by mixing threading up in
a GUI.

PyComplex_AsCComplex does indeed look simple, but my guess is that given the
trouble you are having reproducing, there is a subtle reference-count bug
somewhere, and quite possibly relating to complex numbers.  Given the nature
of such bugs, the place where the crash occurs is generally *not* the place
with the bug.

Unfortunately, we are piling speculation on speculation.  Personally I would
get a debug build running, so a decent stack-trace is available, but I
understand that may not be an option.

Good luck,

Mark.
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