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

Chapter 8.  Actors


"A distributed system is one in which the failure of a computer you didn't even know existed can render your own computer unusable."

 --Leslie Lamport

Throughout this book, we have concentrated on many different abstractions for concurrent programming. Most of these abstractions assume the presence of shared memory. Futures and promises, concurrent data structures, and software transactional memory, are best suited to shared-memory systems. While the shared-memory assumption ensures that these facilities are efficient, it also limits them to applications running on a single computer. In this chapter, we consider a programming model that is equally applicable to a shared-memory machine or a distributed system, namely, the actor model. In the actor model, the program is represented by a large number of entities that execute computations independently, and communicate by passing messages. These independent entities are called actors.

The actor model aims to resolve issues...