The concurrency primitives shown in Chapter 2, Concurrency on the JVM and the Java Memory Model, are the basics of concurrent programming on JVM. Nevertheless, we usually avoid using them directly, as their low-level nature makes them delicate and prone to errors. As we saw, low-level concurrency is susceptible to effects such as data races, reordering, visibility, deadlocks, and nondeterminism. Fortunately, people have come up with more advanced building blocks of concurrency, which capture common patterns in concurrent programs and are a lot safer to use. Although these building blocks do not solve all the issues of concurrent programming, they simplify the reasoning about concurrent programs and can...