Qt application hanging up with 100% CPU

I have a simple Qt program running on Windows XP - its just a data logging program. It reads any data sent to it on the serial port and then it pushes this to the GUI and logs it to a text file.

The thing is, if I run the program for an hour (roughly, sometimes more) it will hang up on me. The GUI locks out and the program stops logging. On the CPU monitor on the performanc开发者_StackOverflow社区e tab of my task manager, one of my cores always goes straight to 100% when this crash happens and stays there until I close the hung application.

I have literally no experience in diagnosing problems like this - has anyone got any tips on where to start?

Run the application until it freezes and then attach a debugger. Look through the threads and check where each one of them is. This should give some clues on what's going on. For threads that are stopped within framework code an investigation of the call stack should show if your code is involved.

Make sure that you do this on a debug build with all symbols included to get readable results.