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


The focus of this chapter has been removing obtrusive concurrency semantics from our code. It simply raises the likelihood of our application's success because we'll have code that's easy to maintain and build upon. The first issue that we tackled was writing concurrent code by making everything concurrent. When there's no guesswork involved, our code is consistent and less susceptible to concurrency bugs.

Then, we looked at various approaches we can take to abstract web worker communication. Helper functions are one option and so is extending the postMessage() method. We then addressed some of the limitations of web workers when we need our UI to be responsive. Even though our large dataset is processed faster, we still have the issue of updating the UI. This is done by treating web workers as generators.

We don't have to write all these JavaScript parallelization tools ourselves. We spent some time looking at the various capabilities and limitations of the Parallel.js library. We...