Blocking event loop in nodejs for different threads

blocking-task.js

const { parentPort } = require('worker_threads');

function blockForSeconds(seconds) {
    const startTime = Date.now();
    let endTime = startTime;
    while (endTime - startTime < seconds * 1000) {
        endTime = Date.now();
    }
}

setTimeout(() => {
    blockForSeconds(2);
    parentPort.postMessage(1);
}, 1000);

setTimeout(() => {
    parentPort.postMessage(1.5);
}, 1500);

main.js

const { Worker } = require('worker_threads');

const path = require('path');

function run() {
    const startTime = performance.now();

    const worker = new Worker(path.join(__dirname, './blocking-task.js'));
    worker.on('message', (time) => {
        const endWorkerTime = performance.now();
        const executionTime = endWorkerTime - startTime;
        console.log(`Other Thread ${time} seconds timeout with one time 2 seconds block execution time: ${executionTime.toFixed(3)} milliseconds`);
    });

    setTimeout(() => {
        const endWorkerTime = performance.now();
        const executionTime = endWorkerTime - startTime;
        console.log(`Main thread 1.5 second timeout execution time: ${executionTime.toFixed(3)} milliseconds`);
    }, 1500);
}

run();


/*
 * Results:
 * Main thread 1.5 second timeout execution time: 1505.867 milliseconds
 * Other Thread 1 seconds timeout with one time 2 seconds block execution time: 3021.362 milliseconds
 * Other Thread 1.5 seconds timeout with one time 2 seconds block execution time: 3021.531 milliseconds
 * 
 * Results shows that every thread handle its own tasks on a specific event loop
 */