// noprotect

var p1 = document.getElementById('p1');

var p2 = document.getElementById('p2');

​

requestAnimationFrame(function (timestamp) {

  console.log('one', timestamp);

​

  // block for 3 second

  var endAt = Date.now() + 3000;

  while (true) {

    if (Date.now() >= endAt) break;

  }

  p1.innerHTML = timestamp;

});

​

requestAnimationFrame(function (timestamp) {

  console.log('two', timestamp);

  // block for 3 second

  var endAt = Date.now() + 3000;

  while (true) {

    if (Date.now() >= endAt) break;

  }

  p2.innerHTML = timestamp;

});

​