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 5. Data-Parallel Collections


"Premature optimization is the root of all evil."

 --Donald Knuth

So far, we have been composing multiple threads of computation into safe concurrent programs. In doing so, we focused on ensuring their correctness. We saw how to avoid blocking in concurrent programs, react to the completion of asynchronous computations, and how to use concurrent data structures to communicate information between threads. All these tools made organizing the structure of concurrent programs easier. In this chapter, we will focus mainly on achieving good performance. We require minimal or no changes in the organization of existing programs, but we will study how to reduce their running time using multiple processors. Futures from the previous chapter allowed doing this to a certain extent, but they are relatively heavyweight and inefficient when the asynchronous computation in each future is short.

Data parallelism is a form of computation where the same computation proceeds...