gistfile1.txt

let last = 0; // last millisecond recorded
let lineno = 0; // current output line number
const iterations = 15;
let count = 0;

function timeout() {
  logline(new Date().getMilliseconds());
  count = count + 1;
  if (count < iterations) {
    setTimeout(timeout, 0);
  }
}

function run() {
  setTimeout(timeout, 0);
 }

function logline(msec) { // msec can't wrap: run duration > 1 second
  const newLine = document.createElement("pre");
  newLine.textContent = `${pad(lineno++, 2)} ${pad(last, 3)} ${pad(msec, 3)}`;
  document.getElementById("log").appendChild(newLine);
  last = msec;
}