Look, there's no easy way to do this. I'm working on a project that is inherently multithreaded. Events come in from the operating system and I have to process them concurrently.
The simplest way to deal with testing complex, multithreaded application code is this: If it's too complex to test, you're doing it wrong. If you have a single instance that has multiple threads acting upon it, and you can't test situations where these threads step all over each other, then your design needs to be redone. It's both as simple and as complex as this.
There are many ways to program for multithreading that avoids threads running through instances at the same time. The simplest is to make all your objects immutable. Of course, that's not usually possible. So you have to identify those places in your design where threads interact with the same instance and reduce the number of those places. By doing this, you isolate a few classes where multithreading actually occurs, reducing the overall complexity of testing your system.
But you have to realize that even by doing this, you still can't test every situation where two threads step on each other. To do that, you'd have to run two threads concurrently in the same test, then control exactly what lines they are executing at any given moment. The best you can do is simulate this situation. But this might require you to code specifically for testing, and that's at best a half step towards a true solution.
Probably the best way to test code for threading issues is through static analysis of the code. If your threaded code doesn't follow a finite set of thread safe patterns, then you might have a problem. I believe Code Analysis in VS does contain some knowledge of threading, but probably not much.
Look, as things stand currently (and probably will stand for a good time to come), the best way to test multithreaded apps is to reduce the complexity of threaded code as much as possible. Minimize areas where threads interact, test as best as possible, and use code analysis to identify danger areas.
I'm not sure if this applies to your question, but the latest news on the Gallio site states :
Gallio and ReSharper 4.0
A few people have asked when Gallio will
support the final release of ReSharper
4.0. Unfortunately there were some last-minute breaking changes between
ReSharper 4.0 Beta and the Final
release. So the ReSharper plugin in
Gallio Alpha 3 Update 2 will not work
anymore. No matter... we plan to
release another update of Gallio later
this week.
Update: just saw this applied to an earlier version than you were using so disregard that.
Best Answer
Turns out that resharper's mstest runner does not work on testrunconfig files that have code coverage enabled. I've worked around the problem by disabling code coverage in my test run config file.