browserWorkers.js

var i=0;
setInterval(()=>console.log(i),1000);
var a=[];
setInterval(function abc(){i++;a.push([Date.now()])},0);

// replace next line with worker
//setInterval(function abc(){i++;a[a.length-1].push(Date.now())},0);

/////
function abcdef() {
  myWorker.postMessage([1, 2]);
  console.log('Message posted to worker');
}
var workerFunc=`
onmessage = function(e) {
  //console.log('Message received from main script');
  //var workerResult = 'Result: ' + (e.data[0] * e.data[1]);
  //console.log('Posting message back to main script');
  setInterval(()=>postMessage(null),0);
}
`;
var blob = new Blob([workerFunc], {type : 'application/javascript'});
var blobUrl=URL.createObjectURL(blob);
var k=[];
for(var i=0;i<10;i++){
    k.push(0);
    ;(function(i){
        var myWorker = new Worker(blobUrl);
        myWorker.onmessage=function(){
            a[k[i]++].push(Date.now());
        };
    }(i));
    
}
abcdef();