How does the async queue work in Node.js?

Short answer: Node.js uses the event loop with phases (timers, I/O callbacks, idle, poll, check, close callbacks) to manage async tasks.

Explain a bit more

Async queues (e.g., with libraries like async.queue) allow you to: Control concurrency (limit how many async tasks run simultaneously). Queue tasks and process them in order. Example with async library: const async = require('async'); const queue = async.queue(async (task) => { await doWork(task); }, 2); // concurrency = 2 queue.push({ id: 1 }); queue.push({ id: 2 }); Node.js internally uses libuv’s thread pool for async I/O, but the event loop manages task scheduling on the single main thread. Additional Important Node.js Questions & Answers Core Concepts & Runtime

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