visionmedia/co-parallel — pull request #3 by dead-horse (2014-03-04 18:30:52+00:00)
Title: support real concurrency

```
var block = true;
function get() {
return function (done) {
setTimeout(done, block ? 100 : 5);
block = false;
};
}

co(function *() {
var tasks = [];
for (var i = 0; i < 200; i++) {
tasks.push(get());
}
var start = Date.now();
yield parallel(tasks, 10);
console.log('total used %dms', Date.now() - start);
})();
```

now it won't block by one slow request. the sample total use from `230ms` decrease to `160ms`