postMessage-vs-setTimeout.js

var postMessageRoundTripCounter = 0;
var setTimeoutRoundTripCounter = 0;

startPostMessageLoop = function(){
  // var lastPostMessageAt = Date.now()
  var receiveMessage = function(message){
    if (message.data !== 'postMessageTest') return;
    // var delta = Date.now() - lastPostMessageAt;
    // console.log('postMessage delta:', delta);
    postMessageRoundTripCounter++;
    postMessage();
  };
  var postMessage = function() {
    // lastPostMessageAt = Date.now()
    window.postMessage('postMessageTest', window.location.toString())
  };
  window.addEventListener("message", receiveMessage, false);
  postMessage();
}

startSetTimeoutLoop = function(){
  var step = function(){
    setTimeoutRoundTripCounter++;
    setTimeout(step, 0);
  }
  step();
}


startPostMessageLoop();
startSetTimeoutLoop();

setInterval(function() {
  console.log('postMessageRoundTripCounter:', postMessageRoundTripCounter);
  console.log('setTimeoutRoundTripCounter:', setTimeoutRoundTripCounter);
}, 1000);