Book Image

Java 9 Concurrency Cookbook, Second Edition - Second Edition

By : Javier Fernández González
Book Image

Java 9 Concurrency Cookbook, Second Edition - Second Edition

By: Javier Fernández González

Overview of this book

Writing concurrent and parallel programming applications is an integral skill for any Java programmer. Java 9 comes with a host of fantastic features, including significant performance improvements and new APIs. This book will take you through all the new APIs, showing you how to build parallel and multi-threaded applications. The book covers all the elements of the Java Concurrency API, with essential recipes that will help you take advantage of the exciting new capabilities. You will learn how to use parallel and reactive streams to process massive data sets. Next, you will move on to create streams and use all their intermediate and terminal operations to process big collections of data in a parallel and functional way. Further, you’ll discover a whole range of recipes for almost everything, such as thread management, synchronization, executors, parallel and reactive streams, and many more. At the end of the book, you will learn how to obtain information about the status of some of the most useful components of the Java Concurrency API and how to test concurrent applications using different tools.
Table of Contents (12 chapters)

Using atomic variables

Atomic variables were introduced in Java version 5 to provide atomic operations on single variables. When you work with a normal variable, each operation that you implement in Java is transformed into several instructions of Java byte code that is understandable by the JVM when you compile the program. For example, when you assign a value to a variable, you only use one instruction in Java; however, when you compile this program, it is transformed into various instructions in the JVM language. This can lead to data inconsistency errors when you work with multiple threads that share a variable.

To avoid these problems, Java introduced atomic variables. When a thread is doing an operation with an atomic variable and if other threads want to do an operation with the same variable, the implementation of the class includes a mechanism to check that the operation is done atomically. Basically, the...