Twitter Future.collect not working at the same time (Scala)

Question

Coming from the background of node.js, I am new to Scala and I tried using Twitter Future.collect to do some simple parallel operations. But my code shows consistent behavior, not simultaneous behavior. What am I doing wrong?

Here is my code,

import com.twitter.util.Future

def waitForSeconds(seconds: Int, container:String): Future[String]  = Future[String] {
  Thread.sleep(seconds*1000)
  println(container + ": done waiting for " + seconds + " seconds")
  container + " :done waiting for " + seconds + " seconds"
}

def mainFunction:String = {
  val allTasks = Future.collect(Seq(waitForSeconds(1, "All"), waitForSeconds(3, "All"), waitForSeconds(2, "All")))
  val singleTask = waitForSeconds(1, "Single")

  allTasks onSuccess  { res =>
    println("All tasks succeeded with result " + res)
  }

  singleTask onSuccess { res =>
    println("Single task succeeded with result " + res)
  }

  "Function Complete"
}

println(mainFunction)

and this is the result that I get

All: done waiting for 1 seconds
All: done waiting for 3 seconds
All: done waiting for 2 seconds
Single: done waiting for 1 seconds
All tasks succeeded with result ArraySeq(All :done waiting for 1 seconds, All :done waiting for 3 seconds, All :done waiting for 2 seconds)
Single task succeeded with result Single :done waiting for 1 seconds
Function Complete

Expected Result:

All: done waiting for 1 seconds
Single: done waiting for 1 seconds
All: done waiting for 2 seconds
All: done waiting for 3 seconds
All tasks succeeded with result ArraySeq(All :done waiting for 1 seconds, All :done waiting for 3 seconds, All :done waiting for 2 seconds)
Single task succeeded with result Single :done waiting for 1 seconds
Function Complete

Answer 1

Twitter , , Scala. , Future.apply (, s.c.Future), , . , , .

API . , , ExecutionContext, . , ( ). Twitter Future Scalaz Task (, , ).

, , , , . - :

import com.twitter.util.{ Future, FuturePool }

val pool = FuturePool.unboundedPool

def waitForSeconds(seconds: Int, container:String): Future[String] = pool {
  Thread.sleep(seconds*1000)
  println(container + ": done waiting for " + seconds + " seconds")
  container + " :done waiting for " + seconds + " seconds"
}

, ( "Function complete", allTasks singleTask ), .

( : FuturePool.unboundedPool - , - . FuturePool API docs , ExecutorService, , .)