Differences between MSVC++ Debug and Release environment

Question

I am dealing with a very peculiar problem at the moment: I have an application that is fully working in Debug-Buildmode, whether I run it from the MSVC environment or start the built executable myself. If I build this application in Release-Buildmode, it is fully working when I run it from the MSVC environment, but shows unexpected behavior when I start it myself.

What differences between the Debug and Release mode could be the reason for this behavior, and why do the problems only occur when I start the executable manually?

It's hard to give code, since it is quite a big project and I have absolutely no clue what could be causing the problem. The program flow is basically:

• Read settings from file (not the problem, double checked the read values, and used an ini- and the libconfig++-library to be sure)
• Distribute values to seperate classes (double checked the passed values)
• One of these classes starts a thread (boost::thread) and triggers callback functions on certain events (these do NOT trigger if release build is executed manually)

Something that I could imagine might cause problems, but I am not sure of:

• Since the classes were written by different people, there is inconsistency between the usage of std::string and std::wstring. I am converting from one to another using std::wstring(s.begin(), s.end()) and vice versa.

Could this be the reason for my problems, and if yes, how do I solve the issue? I would really appreciate some help on this. Thanks in advance.

Update:

• The program does not crash and variables do not seem to have different values when I use the infamous print-debug method (since in the debugger everything works out fine)
• I have read that unitialized variables could be causing this issue and triplechecked every variable used by me, and every variable is initialized properly
• In unit tests, every module I am using works as expected (though I'm not sure I got the border cases right everytime, since I have not written all modules myself).

Update 2:

• While disabling optimization step by step and bringing the release buildmode closer to the debug buildmode I was able to narrow the problem down: **In the code generation tab, my program works with the Multithreaded-Debug-DLL, not the Multithreaded-DLL, regardless to optimization settings.

This seems to be a nice accomplishment, yet I lack the understanding for this problem.

Answer 1

debug do not use optimizations there are optimizations in release mode that is why the exe size is different. Also the libraries used are different even though out of the same codes. you can make release like debug by turning off the optimization options.

Answer 2

Add logging, or eliminate some code blocks. This should allow to find where problem arises. For differences look here:

What is the difference between Debug and Release in Visual Studio?