Book Image

Learning Concurrent Programming in Scala - Second Edition

By : Aleksandar Prokopec
Book Image

Learning Concurrent Programming in Scala - Second Edition

By: Aleksandar Prokopec

Overview of this book

Scala is a modern, multiparadigm programming language designed to express common programming patterns in a concise, elegant, and type-safe way. Scala smoothly integrates the features of object-oriented and functional languages. In this second edition, you will find updated coverage of the Scala 2.12 platform. The Scala 2.12 series targets Java 8 and requires it for execution. The book starts by introducing you to the foundations of concurrent programming on the JVM, outlining the basics of the Java Memory Model, and then shows some of the classic building blocks of concurrency, such as the atomic variables, thread pools, and concurrent data structures, along with the caveats of traditional concurrency. The book then walks you through different high-level concurrency abstractions, each tailored toward a specific class of programming tasks, while touching on the latest advancements of async programming capabilities of Scala. It also covers some useful patterns and idioms to use with the techniques described. Finally, the book presents an overview of when to use which concurrency library and demonstrates how they all work together, and then presents new exciting approaches to building concurrent and distributed systems. Who this book is written for If you are a Scala programmer with no prior knowledge of concurrent programming, or seeking to broaden your existing knowledge about concurrency, this book is for you. Basic knowledge of the Scala programming language will be helpful.
Table of Contents (19 chapters)
Learning Concurrent Programming in Scala - Second Edition
About the Author
About the Reviewers
Customer Feedback

The trouble with atomic variables

Atomic variables from Chapter 3, Traditional Building Blocks of Concurrency, are one of the fundamental synchronization mechanisms. We already know that volatile variables, introduced in Chapter 2, Concurrency on the JVM and the Java Memory Model, allow race conditions, in which the program correctness is subject to the precise execution schedule of different threads. Atomic variables can ensure that no thread concurrently modifies the variable between a read and a write operation. At the same time, atomic variables reduce the risk of deadlocks. Regardless of their advantages, there are situations when using atomic variables is not satisfactory.

In Chapter 6, Concurrent Programming with Reactive Extensions, we implemented a minimalistic web browser using the Rx framework. Surfing around the Web is great, but we would like to have some additional features in our browser. For example, we would like to maintain the browser's history--the list of URLs that were...