Book Image

Mastering Concurrency Programming with Java 9 - Second Edition

By : Javier Fernández González
Book Image

Mastering Concurrency Programming with Java 9 - Second Edition

By: Javier Fernández González

Overview of this book

Concurrency programming allows several large tasks to be divided into smaller sub-tasks, which are further processed as individual tasks that run in parallel. Java 9 includes a comprehensive API with lots of ready-to-use components for easily implementing powerful concurrency applications, but with high flexibility so you can adapt these components to your needs. The book starts with a full description of the design principles of concurrent applications and explains how to parallelize a sequential algorithm. You will then be introduced to Threads and Runnables, which are an integral part of Java 9's concurrency API. You will see how to use all the components of the Java concurrency API, from the basics to the most advanced techniques, and will implement them in powerful real-world concurrency applications. The book ends with a detailed description of the tools and techniques you can use to test a concurrent Java application, along with a brief insight into other concurrency mechanisms in JVM.
Table of Contents (21 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback

An introduction to the Phaser class

The Phaser class is a synchronization mechanism designed to control the execution of algorithms that can be divided into phases in a concurrent way. If you have a process with clearly defined steps, so you have to finish the first one before you can start the second one, and so on, you can use this class to make a concurrent version of your process. The main characteristics of the Phaser class are:

  • The phaser must know the number of tasks it has to control. Java refers to this as the registration of the participants. A participant can register in a phaser any time.
  • The tasks must inform the phaser when they finish a phase. The phaser will make that task sleep until all the participants have finished that phase.
  • Internally, the phaser saves an integer number that stores the number of phase changes the phase has made.
  • A participant can leave the control of the phaser any time. Java refers to this as deregistering the participants.
  • You can execute custom code...