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
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The following exercises summarize what we have learned about futures and promises in this chapter, and require implementing custom future factory methods and combinators. Several exercises also deal with several deterministic programming abstractions that were not covered in this chapter, such as single-assignment variables and maps:

  1. Implement a command-line program that asks the user to input a URL of some website, and displays the HTML of that website. Between the time that the user hits ENTER and the time that the HTML is retrieved, the program should repetitively print a . to the standard output every 50 milliseconds, with a 2 second timeout. Use only futures and promises, and avoid synchronization primitives from the previous chapters. You may reuse the timeout method defined in this chapter.

  2. Implement an abstraction called a single-assignment variable, represented by the IVar class:

                class IVar[T] { 
                  def apply(): T = ??? 
                  def :=(x: T)...