Book Image

Concurrent Patterns and Best Practices

By : Atul S. Khot
Book Image

Concurrent Patterns and Best Practices

By: Atul S. Khot

Overview of this book

Selecting the correct concurrency architecture has a significant impact on the design and performance of your applications. Concurrent design patterns help you understand the different characteristics of parallel architecture to make your code faster and more efficient. This book will help Java developers take a hands-on approach to building scalable and distributed apps by following step-by-step explanations of essential concepts and practical examples. You’ll begin with basic concurrency concepts and delve into the patterns used for explicit locking, lock-free programming, futures, and actors. You’ll explore coding with multithreading design patterns, including master, slave, leader, follower, and map-reduce, and then move on to solve problems using synchronizer patterns. You'll even discover the rationale for these patterns in distributed and parallel applications, and understand how future composition, immutability, and the monadic flow help you create more robust code. By the end of the book, you’ll be able to use concurrent design patterns to build high performance applications confidently.
Table of Contents (14 chapters)

The fork-join pool

Java 7 introduced a specialized executor service, namely, the fork-join API. It dynamically manages the number of threads, based on the available processors, and other parameters such as the number of concurrent tasks. It also employs an important pattern, work stealing—we will soon discuss this.

Egrep – simple version

Let's see the fork-join API in action. We will look at two examples to understand how the API works. The idea is to find a word in a text file. The driver class is EgrepWord:

public class EgrepWord {
private final static ForkJoinPool forkJoinPool = new ForkJoinPool();

The principal theme in the fork-join API is a recursive task. The following class extends a parameterized RecursiveTaskon a List<String>. The following snippet shows the constructor that accepts a line of text and the word to search for:

private static class WordFinder extends RecursiveTask<List<String>> {
final String line;
final String word;

private WordFinder(String line,...