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)

A lock-free FIFO queue

A FIFO (first in, first out) queue is a data structure where the elements are popped out in the same order in which they were inserted. This is in contrast to a stack, where the order is LIFO (last in, first out). In case you need to refresh your memory of these terms, head to

One obvious way for making a queue safer is to use a single lock to make it thread-safe. We could use either an explicit lock (a ReentrantLock) or an intrinsic lock by just making the methods synchronized. 

This will, of course, work; however, it will hurt concurrencyAt any point, only one thread will be able to push or pop the queue. 

Our goal is to increase the concurrency while at the same time ensuring thread safety. Could we allow two threads, one producing elements to the queue and another consuming elements from it? 

The following class shows a thread-safe and bounded FIFO queue using two locks. One lock is used to protect the insertion...