Multithreaded JavaScript. Concurrency Beyond the Event Loop. 1st Ed. 244776

The nature of JavaScript is to be single threaded. This is reflected not only in libraries and applications, but also in online forum posts, books, and online documentation. Thanks to recent advancements in the platform—such as with web workers in the browser, worker_threads in Node.js, and the Atomics and SharedArrayBuffer objects—JavaScript engineers are able to build multi-threaded applications. These features will go down as being the biggest paradigm shift for the world's most popular programming language.
Multithreaded JavaScript explores the various features that JavaScript runtimes have at their disposal for implementing multithreaded programming, using a spectrum of API reference material and high level programming patterns.

• Learn what multithreaded programming is and how you can benefit from it
• Understand the differences between a dedicated worker, a shared worker, and a service worker
• Identify when and when not to use threads in an application
• Orchestrate communication between threads by leveraging the Atomics object
• Understand both the gains and pitfalls of using shared memory
• Benchmark performance to learn when you'll benefit from multiple threads