Book Image

JavaScript Concurrency

By : Adam Boduch
Book Image

JavaScript Concurrency

By: Adam Boduch

Overview of this book

Concurrent programming may sound abstract and complex, but it helps to deliver a better user experience. With single threaded JavaScript, applications lack dynamism. This means that when JavaScript code is running, nothing else can happen. The DOM can’t update, which means the UI freezes. In a world where users expect speed and responsiveness – in all senses of the word – this is something no developer can afford. Fortunately, JavaScript has evolved to adopt concurrent capabilities – one of the reasons why it is still at the forefront of modern web development. This book helps you dive into concurrent JavaScript, and demonstrates how to apply its core principles and key techniques and tools to a range of complex development challenges. Built around the three core principles of concurrency – parallelism, synchronization, and conservation – you’ll learn everything you need to unlock a more efficient and dynamic JavaScript, to lay the foundations of even better user experiences. Throughout the book you’ll learn how to put these principles into action by using a range of development approaches. Covering everything from JavaScript promises, web workers, generators and functional programming techniques, everything you learn will have a real impact on the performance of your applications. You’ll also learn how to move between client and server, for a more frictionless and fully realized approach to development. With further guidance on concurrent programming with Node.js, JavaScript Concurrency is committed to making you a better web developer. The best developers know that great design is about more than the UI – with concurrency, you can be confident every your project will be expertly designed to guarantee its dynamism and power.
Table of Contents (17 chapters)
JavaScript Concurrency
About the Author
About the Reviewer

Sharing application state

In this section, we'll introduce shared workers. First, we'll look at how the same data objects in memory can be accessed by multiple browsing contexts. Then, we'll look at fetching remote resources, and how to notify multiple browsing contexts about the arrival of new data. Finally, we'll look at how shared workers can be leveraged to allow for direct messaging between browser contexts.


Consider this section advanced material for experimental coding. The browser support for shared workers isn't that great at the moment (only Firefox and Chrome). Web workers are still in the candidate recommendation phase at the W3C. Once they become a recommendation and better browser support is in place for shared workers, we'll be ready to use them. For extra motivation, as the service worker spec matures, shared worker proficiency will be all the more relevant.

Sharing memory

The serialization mechanism that we've seen so far with web workers is in place because we cannot...