VS2010 C++ Debugging Issues - Advanced Ways to Debug and Application? - c++

Question

We have a program which is proving difficult to debug. The MFC application runs fine for a few hours but over a day it will crash. Sometimes it will not throw any errors and simply exit the "dlg.DoModal()" section of our code without the user (or any obvious part of the code) closing the dialog. Other times it will crash and throw an error outside of our code and have a horrendous call stack that has nothing to do with our code, it has a lot of calls to system DLLs however.
A bit of background to our problem.
We are trying to develop a MFC bases C++ application (with a dialog). We have multiple threads and the code is rather large which makes debugging a nightmare. We have been experiencing intermittent crashes that we have been unable to locate the source of so far.
We are well past the use of breakpoints for debugging as we are pretty sure it is an issue somewhere in MFC, maybe not a bug but more a problem with the way we are using MFC.
Now we've tried simple things to help us like:
Enable all debug exceptions:
Debug -> Exceptions and then checking all the boxes so that we can
trap silly mistakes.
This proved helpful but we've now corrected all the errors it throws
within a few hours of running.
Search for memory leaks
We then tried Visual Leak Detector (which works beautifully by the
way) located here: http://vld.codeplex.com/ Our code now reports no
memory leaks so it is not an obvious memory leak issue. We have
included vld.h in the very top of our code near the entry point.
Adding Microsoft Symbol Server to obtain debug symbol files.
We then tried making our call stacks more human readable by using MS
Symbol servers shown in these tutorials:
http://social.msdn.microsoft.com/Forums/vstudio/en-US/3f1825e1-6770-48c0-91b0-12d8946ab259/2-how-do-i-configure-visual-studio-to-use-microsoft-symbol-server?forum=vsdebug and http://support.microsoft.com/kb/311503
This ultimately did nothing as it still doesn't tell you enough about any errors.
Using the Thread window to see all call stacks, and using the
Parallel Stack window
We have been using the Thread and Parallel stack windows to aid our
debugging but ultimately they have proved nothing more than pretty
pictures and fancily formatted call stacks that makes you feel good
more than anything. We have been using the tutorial here which has
been very handy
http://www.codeproject.com/Articles/79508/Mastering-Debugging-in-Visual-Studio-A-Beginn
Now for the more interesting things we've tried that do not throw errors straight away but can be detected as problems:
GDI Objects not being destroyed
This one is not obvious in VS2010 as an issue. Basically if you use a call like "CDC* pDC = lChild->GetDC();" and do not use the call "ReleaseDC(pDC);" then you have just created a GDI Object that will not be destroyed until your program terminates. VS2010 is a bit dumb in this regard and will keep creating these objects until your program crashes, and the call stack will look horrible and you will probably have no idea why it has crashed.
To find this issue, start Windows Task Manager -> Click Processes Tab -> Click the View Toolbar item -> Select Columns. Now check Handles, Threads, User Objects, and GDI Objects. Now start your program, find it's process in the list under Image Name, and watch to see if the GDI Objects column keeps growing or stabilizes.
Objects Not being destroyed
This is another not so obvious error, if you create a bitmap like this: "reinterpret_cast(LoadImage( GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_BITMAPNPR), IMAGE_BITMAP, 0, 0, 0))" and assign it straight to a picture control, the bitmap will not be destroyed if you assign another bitmap to this picture control using similar code. Instead you need to assign the above to a HBITMAP variable which you then need to destroy when you are done.
This situation can also arise if you create a font or colour in a similar fashion.
Now with all that being said, we have tried all the methods above and we still can't find our issue. Sometimes our program will exit normally and we won't be given any debug info (this is usually after is has been running overnight), other times our program will lockup the PC (tested on multiple PCs), other times it will throw an error but we can't locate the culprit because it simply points to the ".DoModal()" part of our code and the rest is native windows DLLs which is useless for debugging purposes.
We suspect something is either being created and not destroyed properly but we aren't sure what and VS2010 is not telling us anything useful to point us in the right direction.
Does anyone have any ideas? How do we trap errors that aren't obvious to VS2010? Or rather how do we easily trap "GDI leaks" and the like?
Thanks in advance
Edit:
We've been using Microsoft's Application Verifier, it's found a few errors so far. To use it download it here http://www.microsoft.com/en-us/download/details.aspx?id=20028 run Application Verifier, add your .exe file in your Debug or Release directories and run the program in VS2010 as normal. VS2010 will break when Application Verifier 'sees' an error. It hasn't found anything too outrageous yet so I assume that we still have issues with our code.