Chapter 9 covered some of the ways in which we can use atomic operations to enable hundreds of threads to safely make concurrent modifications to shared data. In this appendix, we’ll look at an advanced method for using atomics to implement locking data structures. On its surface, this topic does not seem much more complicated than anything else we’ve examined. And in reality, this is accurate. You’ve learned a lot of complex topics through this book, and locking data structures are no more challenging than these. So, why is this material hiding in the appendix? We don’t want to reveal any spoilers, so if you’re intrigued, read on, and we’ll discuss this through the course of the appendix.