Concurrent design patterns and guidelines

Designing and implementing concurrent software is hard. Even the basic patterns for controlling access to shared data, such as the ones we saw in the last section, are complex and full of subtle details. Failing to notice one of these details usually results in hard-to-debug data races. To simplify the task of writing concurrent programs, the programming community came up with several guidelines. All of them arise out of earlier disastrous experiences, so take these guidelines seriously. Central to these guidelines is the concept of thread safety guarantees.

Thread safety guarantees

While this is not a pattern, it is a concept that is much broader in scope and one of the key design principles for any concurrent software. Every class, function, module, or component of a concurrent program should specify the thread safety guarantees it provides, as well as the guarantees it requires from the components it uses.

In general, a software...