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)

Customizing the ThreadPoolExecutor class

The Executor framework is a mechanism that allows you to separate thread creation from its execution. It's based on the Executor and ExecutorService interfaces with the ThreadPoolExecutor class that implements both the interfaces. It has an internal pool of threads and provides methods that allow you to send two kinds of tasks and execute them in the pooled threads. These tasks are:

  • The Runnable interface to implement tasks that don't return a result
  • The Callable interface to implement tasks that return a result

In both cases, you only send the task to the executor. The executor uses one of its pooled threads or creates a new one to execute those tasks. It also decides the moment in which the task is executed.

In this recipe, you will learn how to override some methods of the ThreadPoolExecutor class to calculate the execution time of the tasks that you will execute...