No more limits for CPU loads TL;DR; Node.js 10.5 introduced and is a tiny wrapper around them. helps you to spawn new threads with ease, just like calling an anonymous function, interfaced with promises and async/await mechanism. worker threads microjob microjob A brief history of Node.js Node.js is famous for its , a powerful mechanism for handling I/O bound operations with high performance.The early implementations of the asynchronous interface were carried out with callbacks, then they evolved into promises and finally into the well known async/await pattern.Today, , like HTTP requests, DB queries, file system calls, timers, tickers and so on, and of course Node.js is really powerful for these operations.However, . event loop using Node.js for I/O loads is common Node.js has always suffered from a lack of a good system to sustain heavy CPU loads CPU bound operations But what are those “ ”?Here’s a good explanation from a : heavy CPU loads Quora answer Search algorithms Video/Audio/Content conversion/compression algorithms Video streaming Graphics processing/rendering e.g games, videos Heavy mathematical computations like matrix multiplication, calculating factorials, finding prime numbers etc. For these operations, Node.js has always suffered because of its nature: .Wait, what?The main feature of Node.js is the event-loop, a mechanism where threads are spawned and handled underneath. However, this works only with asynchronous operations but and there’s just one thread in execution at a time.Meaning that if a long-running job gets executed, the main thread remains blocked until the execution is finished, blocking the whole system.To prevent such inconvenience, Node.js supports but the . non-blocking single-threaded event-loop the sync ones are executed on a single thread multiprocessing context-switch between processes is expensive Worker threads With version 10.5, Node.js shipped , multithreading in all of its splendor!You can just spawn a new thread and let it handle those heavy CPU loads.So, how does it work?Worker threads come with the and they can communicate with the main thread via .The is really self explaining.Working with events and message passing is good with long-living jobs, where you need to have a running thread in background but what if I want to run just a , carrying a heavy CPU load, in a separated thread? worker threads event interface message passing example inside the docs one-shot function Entering microjob In languages, such as GoLang, you can make it effortlessly with : lightweight routines That is executed in a different thread with an anonymous function defined and invoked inline.What if you can make it in the same way with Node.js’s worker threads?And that’s why I’ve created : fmt.Println microjob A tiny wrapper that allows you to work with , skipping the boring part of instantiating a new thread and sync with it through events. async /await interface What’s under the hood? microjob starts a new thread and sends the given function to it with the desired data, executing (evaluating) it in the specified context.Meaning that you can do this magic pretty like you’d do in GoLang: And you can actually : pass custom data What about having async functions invoked inside the worker?microjob comes with , allowing you to use the async/await pattern inside threads: the whole power of Javascript The future of microjob , due to users’ requests and the constant changing ecosystem of Node.js.It’s having a good feedback from the community, earning something like on Github in the first week, scaling the Github Trending page.Soon, microjob will have its own , then it will be and it will with unit testing. microjob is evolving rapidly 800+ stars thread pool system rewritten in Typescript support CI/CD Finally, I’m glad JS people are so interested in having multithreading in Node.js!
