Strange Exception

Bryan Bulten <[email protected]> Tue, 1 Jul 2003 17:35:04 -0700

Newsgroups	gmane.comp.lib.wxwindows.wxnet
Message-ID	<[email protected]>

Hello,

I've been trying to debug a very strange exception in the Controls
sample.  The exception only happens on MS.NET's CLR, and occurs once
and a while when selecting the 'Panel->Disable All' menu option.

From tracing in VC++ 6.0, I've found that it crashes right when calling
the delegate method's function pointer, in evthandler.cxx (line 40).

At this point, I cannot trace into the function call, and when it does
crash, it seems to crash inside the CLR (the C# code isn't reached),
and very little information is given as to why the crash occurred. 

The only other aspect that I've found is that before the crash occurs, a
garbage collector thread is started.  Could this be the source of the
problem?

Attached is a sample of a typical cordbg.exe output.

Any ideas?  This one has me baffled.


Thanks.

-- 
Bryan Bulten
http://opendev.ods.org/
http://wxnet.sourceforge.net/

cordbg-controls.txt (text/plain, 1.2 KB)

E:\projects\wx.NET\Bin>cordbg controls.exe
Microsoft (R) Common Language Runtime Test Debugger Shell Version 1.0.3705.0
Copyright (C) Microsoft Corporation 1998-2001. All rights reserved.

(cordbg) run controls.exe
Process 1184/0x4a0 created.
Warning: couldn't load symbols for c:\winnt\microsoft.net\framework\v1.0.3705\ms
corlib.dll
[thread 0x538] Thread created.

036:             Controls app = new Controls();
(cordbg) ca t
(cordbg) ca e
(cordbg) cont
Warning: couldn't load symbols for c:\winnt\assembly\gac\system.drawing\1.0.3300
.0__b03f5f7f11d50a3a\system.drawing.dll
[thread 0x540] Thread created.

030:                    Dispose();
(cordbg) cont
[thread 0x538] First chance exception generated: (0x00b3c838) <System.NullRefere
nceException>
  _className=<null>
  _exceptionMethod=<null>
  _exceptionMethodString=<null>
  _message=(0x00b41b10) "Object reference not set to an instance of an object."
  _innerException=<null>
  _helpURL=<null>
  _stackTrace=<null>
  _stackTraceString=<null>
  _remoteStackTraceString=<null>
  _remoteStackIndex=0x00000000
  _HResult=0x80004003
  _source=<null>
  _xptrs=0x0012ef9c
  _xcode=0xc0000005

Thread 0x538 R --- Managed transition ---

(cordbg)

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