topic Re: Exceptions while loading/unloading app in ObjectARX Forum

Exceptions while loading/unloading app

alex_b — Fri, 05 Jun 2009 18:26:36 GMT

Hi

Loading acad from the debugger causes:

"First-chance exception at 0x02ffc1ec in acad.exe: 0xC0000005: Access violation reading location 0x00000004."

and the debugger stops in Wincore.cpp at CWnd::WindowProc().

Continuing and unloading the app causes:

"First-chance exception at 0x00000000 in acad.exe: 0xC0000005: Access violation reading location 0x00000000."

and stops in the same place. before the loadapp dialog returns.

Loading the app again is ok.

Unloading the app once more causes:

"First-chance exception at 0x7830e1c1 (mfc80u.dll) in acad.exe: 0xC0000005: Access violation reading location 0x0000000a."

and stops in Map_pw.cpp at CMapPtrToWord::CAssoc* CMapPtrToWord::GetAssocAt()

(it seems that this one has something to do with the map used in CDocData??)

All this with only Access violation exceptions enabled. If I enable more exceptions, I get more exceptions thrown.

Here is the full list, with all exceptions enabled:

First-chance exception at 0x7c812aeb in acad.exe: Microsoft C++ exception: EEFileLoadException at memory location 0x0012e69c..

First-chance exception at 0x7c812aeb in acad.exe: Microsoft C++ exception: [rethrow] at memory location 0x00000000..

First-chance exception at 0x7c812aeb in acad.exe: Microsoft C++ exception: EEFileLoadException at memory location 0x0012de38..

First-chance exception at 0x7c812aeb in acad.exe: 0xE0434F4D: 0xe0434f4d.

First-chance exception at 0x7c812aeb in acad.exe: Microsoft C++ exception: EEFileLoadException at memory location 0x0012e610..

First-chance exception at 0x7c812aeb in acad.exe: Microsoft C++ exception: [rethrow] at memory location 0x00000000..

First-chance exception at 0x7c812aeb in acad.exe: Microsoft C++ exception: [rethrow] at memory location 0x00000000..

First-chance exception at 0x7c812aeb in acad.exe: 0xE0434F4D: 0xe0434f4d.

First-chance exception at 0x02ffc1ec in acad.exe: 0xC0000005: Access violation reading location 0x00000004.

Alas, this is beyond my feeble capabilities, so I can't make head nor tails of it.

Can someone enlighten me?

Many hanks in advance

alex

Re: Exceptions while loading/unloading app

Anonymous — Fri, 05 Jun 2009 18:35:06 GMT

Alex:

Set the debugger to break when the Access violation exception is thrown,
then examine the stack trace to determine the current state of your
variables. For example, check whether you're using a map before it has been
constructed, or after it has been destroyed (you can tell that this is the
case if it contains garbage values). 🙂
--
Owen Wengerd
President, ManuSoft <>
VP Americas, CADLock, Inc. <>

Re: Exceptions while loading/unloading app

alex_b — Wed, 10 Jun 2009 19:29:52 GMT

Owen

It took me a while (plus being out of town) to make a few checks:

a. It seems that most of the exceptions (save the map-related one) are thrown by every other program I tried, including some OARX samples.

b. It seems that some of them are thrown before the debugged arx begins to load, and even when the arx doesn't load at all. If it's true, they are not related to the program being debugged.! ! !

c. I tried all this on another machine, with similar results. I say similar because on the 2nd machine I got a few new exceptions thrown (one of them related to the acutprintf function).

This is very confusing, in particular the exceptions who seem to be not program-related.

(For the time being I postponed dealing with the map-related one, which is surely some mistake on my part).

Any ideas?

Thanks

alex

Re: Exceptions while loading/unloading app

Anonymous — Wed, 10 Jun 2009 19:40:32 GMT

Alex:

If the other exceptions are not related to your code, then ignore them.
They may indicate an unrelated problem, or they may not. Assuming the
application that throws them also handles them, you just need to set the
debugger to break on unhandled exceptions in order to break only on the one
you're interested in. 🙂
--
Owen Wengerd
President, ManuSoft <>
VP Americas, CADLock, Inc. <>

Re: Exceptions while loading/unloading app

alex_b — Wed, 10 Jun 2009 20:25:41 GMT

>...you just need to set the debugger to {color:#ff00ff}break on unhandled exceptions{color} in order to break only on the one you're interested in.

How do I do that ?

BTW, I find that the EEFileLoadException is thrown when calling managed code from unmanaged. Does autocad do that?

Thanks

alex

Re: Exceptions while loading/unloading app

Anonymous — Thu, 11 Jun 2009 03:45:41 GMT

Alex:

> How do I do that ?

Read through the post and comments here:
http://stevesmithblog.com/blog/visual-studio-break-when-exception-thrown/

> Does autocad do that?

I have no idea. 🙂
--
Owen Wengerd
President, ManuSoft <>
VP Americas, CADLock, Inc. <>

Re: Exceptions while loading/unloading app

alex_b — Thu, 11 Jun 2009 17:52:06 GMT

Owen:

Alas, the link is relevant for managed code only. Handy to have it though for future.

I suppose there is no equivalent solution for unmanaged code? I would sorely need it. 🙂

Thanks

alex

Re: Exceptions while loading/unloading app

Anonymous — Thu, 11 Jun 2009 19:13:56 GMT

Alex:

> Alas, the link is relevant for managed code only.

The link is relevant for both unmanaged and managed code. 🙂
--
Owen Wengerd
President, ManuSoft <>
VP Americas, CADLock, Inc. <>