C# 4.0 Unleashed

Mutexes

Mutual exclusion of code executing simultaneously is the essential idea to tame the concurrency monster. In fact, the concept of a mutex got its name from it. Semaphores are the generalization of mutexes and are discussed in the next section.

Using a mutex, we could make our running example thread safe as follows. This piece of code illustrates the two main operations invoked with a mutex.

Again, the code will be guaranteed to print zero as a result. The basic idea is to use the WaitOne method to wait for the mutex to be released by another thread. When this call returns, we’ve grabbed the mutex and can run with it. When we’re done, we ...