Await.result doesn't cancel Futures on timeout

CancellableFuture.scala

import java.util.concurrent.TimeUnit

import scala.concurrent.duration.Duration
import scala.concurrent.{Await, Future}

/**
 * Test if Futures are cancelled once the duration of
 * the await has timed out.
 *
 * This demonstrates, that even after the 'Await.result'
 * has timed out, the Future that it was waiting on still
 * continues to run.
 *
 *
 * Output:
 *  hello
 *  hello
 *  hello
 *  hello
 *  hello
 *  hello
 *  After await
 *  hello
 *  hello
 *  hello
 */
object CancellableFuture extends App {

  import scala.concurrent.ExecutionContext.Implicits.global

  Future {

    val f = Future {
      while (true) {
        Thread.sleep(300)
        println("hello")
      }
    }

    try {
      Await.result(f, Duration(2, TimeUnit.SECONDS))
    } finally {
      println("After await")
    }
  }

  Thread.sleep(3000)
}

More background: https://github.com/semberal/semberal.github.io/blob/master/scala-future-timeout-patterns.md