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
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Dedication
Preface

Advanced characteristics of executors


An executor is a class that allows programmers to execute concurrent tasks without being worried about the creation and management of threads. Programmers create Runnable objects and send them to the executor that creates and manages the necessary threads to execute those tasks. In Chapter 3, Managing Lots of Threads - Executors, we introduced the basic characteristics of the executor framework:

  • How to create an executor and the different options we have when we create one
  • How to send a concurrent task to an executor
  • How to control the resources used by the executor
  • How the executor, internally, uses a pool of threads to optimize the performance of the application

However, executors can give you many more options to make them a powerful mechanism for your concurrent application.

Cancellation of tasks

You can cancel the execution of a task after you send it to an executor. When you send a Runnable object to an executor using the submit() method, it returns an...