Book Image

Mastering Concurrency Programming with Java 8

By : Javier Fernández González
Book Image

Mastering Concurrency Programming with Java 8

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. All the sub-tasks are combined together once the required results are achieved; they are then merged to get the final output. The whole process is very complex. This process goes from the design of concurrent algorithms to the testing phase where concurrent applications need extra attention. Java includes a comprehensive API with a lot of ready-to-use components to implement powerful concurrency applications in an easy way, but with a high flexibility to adapt these components to your needs. The book starts with a full description of design principles of concurrent applications and how to parallelize a sequential algorithm. We'll show you how to use all the components of the Java Concurrency API from basics to the most advanced techniques to implement them in powerful concurrency applications in Java. You will be using real-world examples of complex algorithms related to machine learning, data mining, natural language processing, image processing in client / server environments. Next, you will learn how to use the most important components of the Java 8 Concurrency API: the Executor framework to execute multiple tasks in your applications, the phaser class to implement concurrent tasks divided into phases, and the Fork/Join framework to implement concurrent tasks that can be split into smaller problems (using the divide and conquer technique). Toward the end, we will cover the new inclusions in Java 8 API, the Map and Reduce model, and the Map and Collect model. The book will also teach you about the data structures and synchronization utilities to avoid data-race conditions and other critical problems. Finally, the book ends with a detailed description of the tools and techniques that you can use to test a Java concurrent application.
Table of Contents (18 chapters)
Mastering Concurrency Programming with Java 8
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Summary


Concurrent programming includes all the necessary tools and techniques to have multiple tasks or process running at the same time in a computer, communicating and synchronizing between them without data loss or inconsistency.

We started this chapter by introducing the basic concepts of concurrency. You must know and understand terms such as concurrency, parallelism, and synchronization to fully understand the examples of this book. However, concurrency can generate some problems, such as data race conditions, deadlocks, livelocks, and others. You must also know the potential problems of a concurrent application. It will help you identify and solve these problems.

We also explained a simple methodology of five steps introduced by Intel to convert a sequential algorithm into a concurrent one and showed you some concurrency design patterns implemented in the Java language and some tips to take into account when you implement a concurrent application.

Finally, we explained briefly the components of the Java concurrency API. It's a very rich API with low- and very high-level mechanisms that allow you to implement powerful concurrency applications easily. We also described the Java memory model, which determines how concurrent applications manage the memory and the execution order of the instructions internally.

In the next chapter, you will learn how to implement applications that use a lot of threads using the executor framework. This allows you to execute a big number of threads by controlling the resources you use and reducing the overhead introduced by thread creation (it reuses Thread objects to execute different tasks).