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
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Lazy values

You should be familiar with lazy values from sequential programming in Scala. Lazy values are the value declarations that are initialized with their right-hand side expression when the lazy value is read for the first time. This is unlike regular values, which are initialized the moment they are created. If a lazy value is never read inside the program, it is never initialized and it is not necessary to pay the cost of its initialization. Lazy values allow you to implement data structures such as lazy streams; they improve complexities of persistent data structures, can boost the program's performance, and help avoid initialization order problems in Scala's mix-in composition.

Lazy values are extremely useful in practice, and you will often deal with them in Scala. However, using them in concurrent programs can have some unexpected interactions, and this is the topic of this section. Note that lazy values must retain the same semantics in a multithreaded program; a lazy value...