Scala API: Run the actor on the default ActorSystem executor.
Java API: Run the actor on the default ActorSystem executor.
Look up an executor definition in the ActorSystem configuration.
Look up an executor definition in the ActorSystem configuration. ExecutorServices created in this fashion will be shut down when the ActorSystem terminates.
Factories for DispatcherSelectors which describe which thread pool shall be used to run the actor to which this configuration is applied. Se the individual factory methods for details on the options.
The default configuration if none of these options are present is to run the actor on the default ActorSystem executor.