public interface Stash extends UnrestrictedStash, RequiresMessageQueue<DequeBasedMessageQueueSemantics>
Stash
trait enables an actor to temporarily stash away messages that can not or
should not be handled using the actor's current behavior.
Example:
class ActorWithProtocol extends Actor with Stash { def receive = { case "open" ⇒ unstashAll() context.become({ case "write" ⇒ // do writing... case "close" ⇒ unstashAll() context.unbecome() case msg ⇒ stash() }, discardOld = false) case "done" ⇒ // done case msg ⇒ stash() } }
Note that the Stash
trait can only be used together with actors that have a deque-based
mailbox. By default Stash based actors request a Deque based mailbox since the stash
trait extends RequiresMessageQueue[DequeBasedMessageQueueSemantics]
.
You can override the default mailbox provided when DequeBasedMessageQueueSemantics
are requested via config:
akka.actor.mailbox.requirements { "akka.dispatch.BoundedDequeBasedMessageQueueSemantics" = your-custom-mailbox }Alternatively, you can add your own requirement marker to the actor and configure a mailbox type to be used for your marker.
For a Stash
that also enforces unboundedness of the deque see UnboundedStash
. For a Stash
that does not enforce any mailbox type see UnrestrictedStash
.
Note that the Stash
trait must be mixed into (a subclass of) the Actor
trait before
any trait/class that overrides the preRestart
callback. This means it's not possible to write
Actor with MyActor with Stash
if MyActor
overrides preRestart
.
Actor.emptyBehavior$, Actor.ignoringBehavior$
postStop, preRestart
aroundPostRestart, aroundPostStop, aroundPreRestart, aroundPreStart, aroundReceive, context, postRestart, preStart, receive, self, sender, supervisorStrategy, unhandled
actorCell, clearStash, context, enqueueFirst, mailbox, prepend, self, stash, unstash, unstashAll, unstashAll