perf.js

const cluster = require('cluster');
const numWorkers = 4;
let totalTrials = 0;
const numOpsToRunPerTrial = 5000000;

if (cluster.isMaster) {
  console.log(`Master ${process.pid} is running`);

  // Fork workers.
  for (let i = 0; i < numWorkers; i++) {
    cluster.fork();
  }

  function messageHandler(msg) {
    totalTrials += msg.trials;
  }

  function reportAndExit() {
    // Calculate the total ops/ms
    const elapsedMs = process.uptime();
    const opsPerMs = (totalTrials * numOpsToRunPerTrial) / elapsedMs;
    console.log(`Ops/ms: ${opsPerMs}`)
    process.exit();
  }

  // Listen for trial reports from each worker.
  for (const id in cluster.workers) {
    cluster.workers[id].on('message', messageHandler);
  }

  process.on('SIGINT', function () {
    reportAndExit();
  });

  process.on('SIGTERM', function () {
    reportAndExit();
  });
} else {
  // The payload of work to do
  let localTrials = 0;

  function doWork() {
    for (let i = 0; i < numOpsToRunPerTrial; ++i) {
      Math.sqrt(Math.random() + Math.random());
    }
    localTrials++;
    setImmediate(doWork); // Yield to the event loop to allow process signal trapping
  }

  doWork();

  console.log(`Worker ${process.pid} started`);

  setInterval(function() {
    process.send({trials: localTrials});
    localTrials = 0;
  }, 1000);
}