Lock-free programming

Lock-free programming is hard. We will not spend a lot of time discussing lock-free programming in this book, but instead I will provide you with an example of how a very simple lock-free data structure could be implemented. There is a great wealth of resources — on the web and in books (such as the Anthony Williams book mentioned earlier) — dedicated to lock-free programming that will explain the concepts you need to understand before writing your own lock-free data structures. Some concepts you might have heard of, such as compare-and-swap (CAS) and the ABA problem, will not be further discussed in this book.

Example: A lock-free queue

Here, you are going to see an example of a lock-free queue, which is a relatively simple but useful lock-free data structure. Lock-free queues can be used for one-way communication with threads that cannot use locks to synchronize access to shared data.

Its implementation is straightforward because of...