Yes, the message queue will have higher importance than timeouts one, and will thus fire at higher frequency. You can bind to that queue quite easily with the MessageChannel API: let i = 0; let j = 0; const channel = new MessageChannel(); channel.port1.onmessage = messageLoop; function messageLoop() { i++; // loop channel.port2.postMessage(“”); } function … Read more
Each event loop has a microtask queue and a macrotask queue. A microtask is a task that is originally to be queued on the microtask queue rather than a task queue. Refer to https://www.w3.org/TR/html51/webappapis.html#microtask-queue. There are two kinds of microtasks: solitary callback microtasks, such as Promiseļ¼ and compound microtasks, such as Object.observe, MutationObserver and process.nextTick … Read more
Remember that while JavaScript is single-threaded, all of node’s I/O and calls to native APIs are either asynchronous (using platform-specific mechanisms), or run on a separate thread. (This is all handled through libuv.) So when there’s data available on a socket or a native API function has returned, we need a synchronized way to invoke … Read more
I have been personally reading the source code of node.js & v8. I went into a similar problem like you when I tried to understand node.js architecture in order to write native modules. What I am posting here is my understanding of node.js and this might be a bit off track as well. Libev is … Read more
One go-around of the event loop will have exactly one task being processed from the macrotask queue (this queue is simply called the task queue in the WHATWG specification). After this macrotask has finished, all available microtasks will be processed, namely within the same go-around cycle. While these microtasks are processed, they can queue even … Read more
1: If we are talking about a single-threaded application, then what processes setTimeouts while JS engine accepts more requests and executes them? Isn’t that single thread will continue working on other requests? Then who is going to keep working on setTimeout while other requests keep coming and get executed. There’s only 1 thread in the … Read more
When you join the new thread in the main thread, it will wait until the thread finishes, so the GUI will block even though you are using multithreading. If you want to place the logic portion in a different class, you can subclass Thread directly, and then start a new object of this class when … Read more
In the question, there existed a race condition between: The browser’s attempt to initialize the drop-down list, ready to have its selected index updated, and Your code to set the selected index Your code was consistently winning this race and attempting to set drop-down selection before the browser was ready, meaning that the bug would … Read more