Why does Microsoft Visual C# 2008 Express Edition debugger randomly exit?

Question

I am writing a multi-threaded Windows application in Microsoft Visual C# 2008 Express Edition. Recently, the debugger has been acting strangely.

While I am Stepping

Answer 1

I've seen this a few times. It generally happens when there's a context switch to another thread. So you might be stepping through thread with ID 11, you hit F10, and there's a pre-emptive context switch so now you're running on thread ID 12 and so Visual Studio merrily allows the code to continue.

There are some good debugging tips here:

Tip: Break only when a specific thread calls a method: To set a per-thread breakpoint, you need to uniquely identify a particular thread that you have given a name with its Name property. You can set a conditional breakpoint for a thread by creating a conditional expression such as "ThreadToStopOn" == Thread.CurrentThread.Name .

You can manually change the name of a thread in the Watch window by watching variable "myThread" and entering a Name value for it in the value window. If you don't have a current thread variable to work with, you can use Thread.CurrentThread.Name to set the current thread's name. There is also a private integer variable in the Thread class, DONT_USE_InternalThread, this is unique to each thread. You can use the Threads window to get to the thread you want to stop on, and in the Watch window, enter Thread.CurrentThread.DONT_USE_InternalThread to see the value of it so you can create the right conditional breakpoint expression.

EDIT: There are also some good tips here. I found this by googling for 'visual studio prevent thread switch while debugging'.