akka - Is it possible to await for second response in Scala -

let's have actor a. expects receive message , once receives message sends 2 messages back.

a extends actor {   def receive: receive = {     case m1 =>       context.sender ! m2       context.sender ! m3   } } 

and in actor want send message , await 2 responses. know that's easy 1 response in way like

val task = ? m1 await.result(task, timeout) 

but i'm not sure whether possible 2 sequential messages.

it important send 2 separate messages need await first of them in place.

you can solve problem introducing intermediate actor in cases when need wait both messages.

this actor this:

class aggregationactor(aactor: actorref) extends actor {    var awaitform2: option[m2] = none   var awaitform3: option[m3] = none   var originalsender: option[actorref] = none    def receive: receive = {     case m1 =>       // save sender       originalsender = some(sender())       // proxy message       aactor ! m1     case m2 =>       awaitform2 = some(m2)       checkifbothmessageshavearrived()     case m3 =>       awaitform3 = some(m3)       checkifbothmessageshavearrived()   }    private def checkifbothmessageshavearrived() = {     {       m2 <- awaitform2       m3 <- awaitform3       s <- originalsender     } {       // send tuple       s ! (m2, m3)       // shutdown, our task done       context.stop(self)     }   }  } 

essentially has internal state , keeps track of how m1 , m2 responses arriving.

you use like:

def awaitbothmessages(input: m1, underlyingaactor: actorref, system: actorsystem): future[(m2, m3)] = {   val aggregationactor = system.actorof(props(new aggregationactor(aactor)))   (aggregationactor ? input).mapto[(m2, m3)] }  val system = actorsystem("test") val aactor = system.actorof(props(new a), name = "aactor")  // awaiting first message only: val firstmessage = aactor ? m1 val first = await.result(firstmessage, duration.inf)  // awaiting both messages: val bothmessages: future[(m2, m3)] = awaitbothmessages(m1, aactor, system) val both = await.result(firstmessage, duration.inf)