Demonstrating Node.js single threadness

server.js

var http = require('http');
var getTime = function() {
	var d = new Date();
	return 	d.getHours() + ':' + d.getMinutes() + ':' + 
			d.getSeconds() + ':' + d.getMilliseconds();
}
var respond = function(res, str) {
	res.writeHead(200, {'Content-Type': 'text/plain'});
  	res.end(str + '\n');
  	console.log(str + ' ' + getTime());
}
var handleRequest = function (req, res) {
	console.log('new request: ' + req.url + ' - ' + getTime());
	if(req.url == '/immediately') {
		respond(res, 'A');
	} else {
		var now = new Date().getTime();
		while(new Date().getTime() < now + 5000) {
		   // synchronous reading of the file
		}
	  	respond(res, 'B');
  	}
}
http.createServer(handleRequest).listen(9000, '127.0.0.1');