Mutexes

A mutex (short for "mutual exclusion") is a synchronization object that is used in concurrent programming to protect a shared resource from simultaneous access by multiple threads or processes. A mutex provides exclusive ownership of a resource, meaning that only one thread or process can acquire the mutex at a time. Other threads or processes that try to acquire the mutex while it is held by another thread or process are blocked until the mutex is released.

In C#, the Mutex class is provided by the System.Threading namespace. To use a mutex, you first create an instance of the Mutex class, passing a name and a boolean value that specifies whether the mutex is initially owned by the calling thread or process. The mutex can then be acquired by calling the WaitOne() method, which blocks the calling thread or process until the mutex is released.

Once a thread or process has acquired the mutex, it can access the shared resource without interference from other threads or processes that are blocked on the mutex. When the thread or process is finished with the resource, it releases the mutex by calling the ReleaseMutex() method, which allows another thread or process to acquire the mutex.

One important thing to keep in mind when using a mutex is that it is a heavyweight synchronization object that can be expensive to create and maintain, particularly if it needs to be shared across multiple processes. As such, it should be used judiciously and only when necessary. In some cases, lighter-weight synchronization objects like Monitor or ReaderWriterLockSlim may be more appropriate.