node-future.js

var cluster = require('cluster');
var fs = require('fs');

if (!cluster.isMaster) {
	process.on('message', function (e) {
		e.args.unshift(function (result) {
			fs.writeFileSync(e.path + '~', JSON.stringify({ result : result }));
			fs.renameSync(e.path + '~', e.path);
			process.exit();
		});
		eval('(' + e.process + ')').apply(this, e.args);
	});
	return;
}

function future (process) {
	var args   = Array.prototype.slice.call(arguments, 1);
	var temp   = '/tmp/' + Math.random().toString(16);
	var worker = cluster.fork();
	var result;
	worker.send({ process: process.toString(), args: args, path : temp });

	var ret = {
		resolved : false,
		result : undefined,
		valueOf : function () {
			if (!this.resolved) {
				while (1) {
					try {
						result = fs.readFileSync(temp);
						fs.unlinkSync(temp);
						break;
					} catch (e) { }
				}
				this.resolved = true;
				this.result = JSON.parse(result).result;
			}

			return this.result;
		}
	};
	return ret;
}

var foo = future(function (cb) { setTimeout(function () { cb(2) }, 2000) });
var bar = future(function (cb) { setTimeout(function () { cb(3) }, 3000) });

console.log(new Date() + '');

// block
console.log([foo + bar]);

console.log(new Date() + ' / 3 second (not 6 second) blocked?');

// non-block
console.log([foo + bar]);
console.log(new Date());
console.log('non blocked?');


console.log('sleep // this is just busy loop :)');
function sleep (n) { future(function (cb, n) { console.log(n); setTimeout(cb, n) }, n).valueOf() }
sleep(1000);

console.log('done!');