window.URL = window.URL || window.webkitURL || window.mozURL || window.msURL || window.oURL; var code = `function single(iterations) { let o; for (let i = 1; i < iterations; i += 1) { o = { a: Math.random() }; o.a += Math.random(); } return o; } onmessage = function (e) { postMessage(single(e.data.iterations)); close(); };`; var bb = new Blob([code], { type: 'text/javascript' }); var bbURL = URL.createObjectURL(bb); var worker = new Worker(bbURL); function parallel(iterations) { worker.onmessage = function (e) { URL.revokeObjectURL(bbURL); deferred.resolve(); }; worker.postMessage({ iterations }); } function single(iterations) { let o; for (let i = 1; i < iterations; i += 1) { o = { a: Math.random() }; o.a += Math.random(); } return o; }