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 2. Concurrency on the JVM and the Java Memory Model


"All non-trivial abstractions, to some degree, are leaky."

 --Jeff Atwood

Since its inception, Scala has run primarily on top of JVM, and this fact has driven the design of many of its concurrency libraries. The memory model in Scala, its multithreading capabilities, and its inter-thread synchronization are all inherited from the JVM. Most, if not all, higher-level Scala concurrency constructs are implemented in terms of the low-level primitives presented in this chapter. These primitives are the basic way to deal with concurrency-in a way, the APIs and synchronization primitives in this chapter constitute the assembly of concurrent programming on the JVM.

In most cases, you should avoid low-level concurrency in place of higher-level constructs introduced later, but we felt it was important for you to understand what a thread is, that a guarded block is better than busy-waiting, or why a memory model is useful. We are convinced that...