fibthreads.js

'use strict';

const assert = require('assert');
const fibonacci = require('fibonacci');
const {
  Worker,
  MessageChannel,
  MessagePort,
  isMainThread,
  parentPort,
  workerData
} = require('worker_threads');

if (isMainThread) {
  const express = require('express');
  const app = express();
  const port = 3000;

  app.get('/status', (req, res) => {
    res.send('OK');
  });

  app.get('/fibonacci', (req, res) => {
    const worker = new Worker(__filename, {
      workerData: { iterations: req.query.iterations || 10 }
    });
    const subChannel = new MessageChannel();
    worker.postMessage({ hereIsYourPort: subChannel.port1 }, [
      subChannel.port1
    ]);
    subChannel.port2.on('message', value => {
      console.log('received:', value);
      res.send(value);
    });
  });

  app.listen(port, () => {
    console.log(`FibThreads app listening on port ${port}`);
  });
} else {
  parentPort.once('message', value => {
    console.log(workerData);
    assert(value.hereIsYourPort instanceof MessagePort);
    console.log(`Starting Fibonacci sequence with ${workerData.iterations} iterations...`);
    const result = fibonacci.iterate(workerData.iterations);
    console.log(`Done (${result.ms} ms)`);
    value.hereIsYourPort.postMessage(result.number);
    value.hereIsYourPort.close();
  });
}