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

What are atomics?

What are atomics? Atomics, or, more precisely, an atomic operation, is an operation which happens in one go, not in steps. It is like an atom --indivisible (although an atom is technically divisible, let's not destroy the analogy).

An atomic operation is a single operation as seen by all other working threads. It just happens immediately. It is like the execution of one machine code, which is either not done yet or is completed. There is no in-between.

In a nutshell, something being atomic means that only one operation can be done on it at a time. For example, updating a variable can be made atomic. This can be used to avoid a race condition.

Information about lock and mutex

When I said updating a variable can be made atomic, it means that during the time a thread is accessing that memory, no other thread should be allowed to access it. This is only possible when you introduce a lock or a mutex (mutual exclusion) on the variable being accessed. This way, the other thread knows...