Ponylangとこれからの並行プログラミング19. class Counter extends Actor { val set = mutable.Set[Int]() def receive = { case data: Int => set.add(data) resetter ! set } } class Resetter extends Actor { def receive = { case set: mutable.Set[_] => if(set.size > 10) set.clear() } } mutable ※ code Pony ※ scala var + immutable copy https://doc.akka.io/docs/akka/2.5.6/scala/general/jmm.html#actors-and-shared-mutable-state race-condition
