worker.js

// Do the actual work of getting a message
console.log('worker.js launched');
function getMessage() {
  var x = new XMLHttpRequest();
  x.open('GET', 'serviceworker/sleep/?action=timeout&user=ben&id=testing1234567890', false);
  //x.responseType = "arraybuffer";

  var result = [];
  x.onload = function(e) {
    if (e.target.response) {
       result.push[e.target.response];
    } else {
      console.log('response is null');
    }
  }
  console.log('worker.js send+');
  x.send(null);
  console.log("worker.js: send- result: " + result);
  return result;
}

// Do busy-waiting, do not proceed until we get a message
function subReceiveMessage() {
  do {
    var message = getMessage();
    if (message.length > 0) {
      console.log("worker.js receive msg:" + message);
      return message;
    }
  } while (1);
}

(function workerStart() {
  console.log('workerStart+');
  for (;;) {
    do {
        var message = subReceiveMessage();
        if (message) {
            console.log("worker.js receive msg:" + message);
            break;
        }
    } while(100);
  }
})();