weevil-deval.js

var weevil = require('weevil');
var deval = require('deval');

console.log('Lets do something that should be blocking:');

//this code will be run in a webworker
var worker = weevil(deval(function () {
  var start = +new Date(); 
  
  for (var i=0; i<10000000000000; i++) {
    //blockety block
  }
  var end = +new Date();
  weevil.send('DONE!', end - start);
}));

var interval = setInterval(function () {
  console.log('Look, I aint blocked!');
}, 50);

worker.on('DONE!', function (time) {
  console.log('Count was done in', time + 'ms');a
  clearInterval(interval);
});

//Outputs:
//  Lets do something that should be blocking:
//  Look, I aint blocked!
//  Look, I aint blocked!
// ...
//  Look, I aint blocked!
//  Count was done in 2061ms