Because Akka uses non-daemonic threads, so it'll keep the app running until you
shut-down the ActorSystem.
You can do so via:
import system.dispatcher
s.runForeach(println).onComplete { _ => system.terminate() }
--
Cheers,
Konrad 'ktoso’ Malawski
Akka @ Lightbend
On 23 February 2016 at 18:11:36, Matthew Adams ([email protected]) wrote:
NB: posted at
http://stackoverflow.com/questions/35583739/why-does-this-simple-akka-streams-program-never-terminate
before I thought to post here.
Should be a simple question. I'm using Akka 2.4.2 (contains Akka Streams &
HTTP). I expected this Source to complete & the program to terminate because
the Source is finite, but it never does. Why doesn't this program terminate?
import scala.concurrent._
import scala.collection.immutable._
import akka._
import akka.actor._
import akka.stream._
import akka.stream.scaladsl._
import akka.util._
object Test extends App {
implicit val system = ActorSystem("TestSystem")
implicit val materializer = ActorMaterializer()
val s = Source.single(1)
s.runForeach(println)
}
Output:
$ sbt run
...
[info] Running Test
[DEBUG] [02/23/2016 10:59:19.904] [run-main-0] [EventStream(akka://TestSystem)]
logger log1-Logging$DefaultLogger started
[DEBUG] [02/23/2016 10:59:19.904] [run-main-0] [EventStream(akka://TestSystem)]
Default Loggers started
1
Relevant portion of my build.sbt file:
scalaVersion := "2.11.7"
scalacOptions := Seq("-unchecked", "-deprecation", "-encoding", "utf8")
libraryDependencies ++= {
val akkaVersion = "2.4.2"
Seq(
"com.typesafe.akka" %% "akka-stream" % akkaVersion
)
}
-matthew
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--
>>>>>>>>>> Read the docs: http://akka.io/docs/
>>>>>>>>>> Check the FAQ:
>>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html
>>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user
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