setImmediate overhead

gistfile1.txt

function getOverhead() {
  return new Promise(function (resolve) {
    var overhead    = [0, 0];
    var isCompleted = false;

    function handler() {
      if (isCompleted) {
        resolve(overhead[0] + overhead[1] / 1e9);
        return;
      }

      var overheadStart = process.hrtime();
      setImmediate(function () {
        var diff = process.hrtime(overheadStart);
        overhead[0] += diff[0];
        overhead[1] += diff[1];
        handler();
      });
    }

    handler();

    setTimeout(function () {
      isCompleted = true;
    }, 10000);
  });
}

getOverhead()
.then(function (overhead) {
  console.log('overhead', overhead);
});