Unit Testing Concurrent Code

Question

My weekend project consists of writing a cross-platform concurrency primitives library (critical sections, read/write mutexes, interlocked integers, events, etc) and was won

Answer 1

Don't think about unit tests, think about the behaviour you want to specify. For example:

Given_an_unlocked_lock
    It_should_be_possible_to_take_it
Given_a_locked_lock
    It_should_not_be_possible_to_take_it_from_another_thread
    It_should_be_possible_take_it_from_the_same_thread
Given_a_locked_lock_when_unlocked
    It_should_be_possible_to_take_it
Given_a_locked_lock_when_owning_thread_terminates
    It_should_be_possible_to_take_it

I think that will help you identify what to do. And yes probably you need a helper thread in your unit tests to make it happen. Maybe this example is helpful.