Having to do 3 requests, d how can i do them parallel?

auto category = redis.getDatabase().send("HGETALL category:1");
auto user = redis.getDatabase().send("HGETALL user:1");
auto test = redis.getDatabase().send("HGETALL test:3");

I tried, with async from vibe.core.concurrency, but i got less performance.
Tried with .parallel but it crash's since the threads gets messed up.

How are you guys doing parallel requests? Like promises all.

Ex javascript promises.

Promise.all([p1, p2, p3]).then(values => { 
  console.log(values); // [3, 1337, "foo"] 
});