Book Image

Mastering Concurrency Programming with Java 9, Second Edition - Second Edition

By : Javier Fernández González
Book Image

Mastering Concurrency Programming with Java 9, Second Edition - 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

Chapter 10. Asynchronous Stream Processing - Reactive Streams

Reactive streams (http://www.reactive-streams.org/) define a standard for asynchronous stream processing with non-blocking back pressure. The biggest problem with these kinds of systems is resource consumption. A fast producer can overload a slower consumer. The queue of data between those components can increase its size in excess and affects the behavior of the whole system. The back pressure mechanism ensures that the queue which mediates between the producer and a consumer has a limited number of elements.

Reactive streams define a minimal set of interfaces, methods, and protocols that describe the necessary operations and entities. They are based on the following three elements:

  • A publisher of information
  • One or more subscribers of that information
  • A subscription between the publisher and a consumer

The reactive streams specification determines how these classes should interact between them, according to the following rules:

  • The...