Node non blocking using workers

node-express-non-blocking.js

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

const app = express();

app.get('/', function (req, res) {
  const worker = new Worker(__dirname + '/worker.js', {
    workerData: { ping: 'pong' },
  });
  worker.on('message', (pi) => {
    res.send(`Pi Value, ${pi}`);
  });
  worker.on('error', (err) => {
    res.status({ status: 500 }).json({ message: err.message });
  });
  worker.on('exit', (code) => {
    if (code !== 0) {
      res.status({ status: 500 }).json({ message: code });
    }
  });
  worker.postMessage('getMeThePiValue');
});

app.get('/hello', function (req, res) {
  res.send(`hello world`);
});

app.listen(3000);

worker.js

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

function getPi() {
  let sum = 0;
  for (let n = 0; n < 10000000000; n++) {
    let mult = n % 2 === 0 ? 1 : -1;
    sum += mult * (1 / (2 * n + 1));
  }
  return sum * 4;
}

parentPort.on('message', (param) => {
  console.log(param); // getMeThePiValue
  console.log(workerData); // { ping: 'pong'}
  const pi = getPi();
  parentPort.postMessage(pi);
});