Book Image

Learn ECMAScript - Second Edition

By : MEHUL MOHAN, Narayan Prusty
Book Image

Learn ECMAScript - Second Edition

By: MEHUL MOHAN, Narayan Prusty

Overview of this book

Learn ECMAScript explores implementation of the latest ECMAScript features to add to your developer toolbox, helping you to progress to an advanced level. Learn to add 1 to a variable andsafely access shared memory data within multiple threads to avoid race conditions. You’ll start the book by building on your existing knowledge of JavaScript, covering performing arithmetic operations, using arrow functions and dealing with closures. Next, you will grasp the most commonly used ECMAScript skills such as reflection, proxies, and classes. Furthermore, you’ll learn modularizing the JS code base, implementing JS on the web and how the modern HTML5 + JS APIs provide power to developers on the web. Finally, you will learn the deeper parts of the language, which include making JavaScript multithreaded with dedicated and shared web workers, memory management, shared memory, and atomics. It doesn’t end here; this book is 100% compatible with ES.Next. By the end of this book, you'll have fully mastered all the features of ECMAScript!
Table of Contents (18 chapters)
Title Page
PacktPub.com
Contributors
Preface
Index

What is shared memory?


Let's suppose we are working on a real-time performance-critical application, which is the reason we're so concerned about this interesting topic. Suppose I have two web workers running in the background, and I want to share some data from one worker to another. Web workers run independently on separate OS-level threads and have no idea about each other.

One way is to make use of postMessage to transfer messages between web workers, as we saw in the last chapter. However, this is slow.

Another way is to transfer the object to another worker completely; however, if you remember, that makes the object which is transferred inaccessible from the worker which sent it.

The solution to this problem is SharedArrayBuffer.

Introduction to SharedArrayBuffer

The SharedArrayBuffer is the way to create a memory store which is accessible to all workers simultaneously. Now, if you've been reading keenly, you will have understood something mischievous that can happen once something like...