remove deprecated ActorSystem termination methods, #21423

* those were deprecated by #15757 before 2.4.0

akka-actor-tests/src/test/scala/akka/actor/ActorSystemSpec.scala

@@ -197,30 +197,26 @@ class ActorSystemSpec extends AkkaSpec(ActorSystemSpec.config) with ImplicitSend
       import system.dispatcher
       system2.scheduler.scheduleOnce(200.millis.dilated) { system2.terminate() }
 
-      system2.awaitTermination(5 seconds)
       Await.ready(system2.whenTerminated, 5 seconds)
       callbackWasRun should ===(true)
     }
 
     "return isTerminated status correctly" in {
       val system = ActorSystem().asInstanceOf[ActorSystemImpl]
-      system.isTerminated should ===(false)
       val wt = system.whenTerminated
       wt.isCompleted should ===(false)
       val f = system.terminate()
       val terminated = Await.result(wt, 10 seconds)
+      system.whenTerminated.isCompleted should ===(true)
       terminated.actor should ===(system.provider.rootGuardian)
       terminated.addressTerminated should ===(true)
       terminated.existenceConfirmed should ===(true)
       terminated should be theSameInstanceAs Await.result(f, 10 seconds)
-      system.awaitTermination(10 seconds)
-      system.isTerminated should ===(true)
     }
 
     "throw RejectedExecutionException when shutdown" in {
       val system2 = ActorSystem("AwaitTermination", AkkaSpec.testConf)
       Await.ready(system2.terminate(), 10 seconds)
-      system2.awaitTermination(10 seconds)
 
       intercept[RejectedExecutionException] {
         system2.registerOnTermination { println("IF YOU SEE THIS THEN THERE'S A BUG HERE") }

akka-actor-tests/src/test/scala/akka/event/AddressTerminatedTopicBenchSpec.scala

@@ -44,7 +44,7 @@ class AddressTerminatedTopicBenchSpec extends AkkaSpec("akka.loglevel=INFO") {
         shutdown(sys, 10.seconds, verifySystemShutdown = true)
         log.info("Stopping {} actors took {} ms", num, (System.nanoTime() - t2).nanos.toMillis)
       } finally {
-        if (!sys.isTerminated) shutdown(sys)
+        shutdown(sys)
       }
     }
 

akka-actor/src/main/scala/akka/actor/ActorSystem.scala

@@ -523,42 +523,6 @@ abstract class ActorSystem extends ActorRefFactory {
    */
   def registerOnTermination(code: Runnable): Unit
 
-  /**
-   * Block current thread until the system has been shutdown, or the specified
-   * timeout has elapsed. This will block until after all on termination
-   * callbacks have been run.
-   *
-   * Throws TimeoutException in case of timeout.
-   */
-  @deprecated("Use Await.result(whenTerminated, timeout) instead", "2.4")
-  def awaitTermination(timeout: Duration): Unit
-
-  /**
-   * Block current thread until the system has been shutdown. This will
-   * block until after all on termination callbacks have been run.
-   */
-  @deprecated("Use Await.result(whenTerminated, Duration.Inf) instead", "2.4")
-  def awaitTermination(): Unit
-
-  /**
-   * Stop this actor system. This will stop the guardian actor, which in turn
-   * will recursively stop all its child actors, then the system guardian
-   * (below which the logging actors reside) and the execute all registered
-   * termination handlers (see [[ActorSystem#registerOnTermination]]).
-   */
-  @deprecated("Use the terminate() method instead", "2.4")
-  def shutdown(): Unit
-
-  /**
-   * Query the termination status: if it returns true, all callbacks have run
-   * and the ActorSystem has been fully stopped, i.e.
-   * `awaitTermination(0 seconds)` would return normally. If this method
-   * returns `false`, the status is actually unknown, since it might have
-   * changed since you queried it.
-   */
-  @deprecated("Use the whenTerminated method instead.", "2.4")
-  def isTerminated: Boolean
-
   /**
    * Terminates this actor system. This will stop the guardian actor, which in turn
    * will recursively stop all its child actors, then the system guardian
@@ -820,11 +784,6 @@ private[akka] class ActorSystemImpl(
   def start(): this.type = _start
   def registerOnTermination[T](code: ⇒ T) { registerOnTermination(new Runnable { def run = code }) }
   def registerOnTermination(code: Runnable) { terminationCallbacks.add(code) }
-  override def awaitTermination(timeout: Duration) { Await.ready(whenTerminated, timeout) }
-  override def awaitTermination() = awaitTermination(Duration.Inf)
-  override def isTerminated = whenTerminated.isCompleted
-
-  override def shutdown(): Unit = terminate()
 
   override def terminate(): Future[Terminated] = {
     if (!settings.LogDeadLettersDuringShutdown) logDeadLetterListener foreach stop

akka-stream-tests-tck/src/test/scala/akka/stream/tck/ActorSystemLifecycle.scala

@@ -13,6 +13,7 @@ import akka.event.Logging
 import akka.testkit.TestEvent
 import akka.testkit.EventFilter
 import org.testng.annotations.BeforeClass
+import scala.concurrent.Await
 
 trait ActorSystemLifecycle {
 
@@ -31,8 +32,7 @@ trait ActorSystemLifecycle {
   @AfterClass
   def shutdownActorSystem(): Unit = {
     try {
-      system.terminate()
-      system.awaitTermination(shutdownTimeout)
+      Await.ready(system.terminate(), shutdownTimeout)
     } catch {
       case _: TimeoutException ⇒
         val msg = "Failed to stop [%s] within [%s] \n%s".format(system.name, shutdownTimeout,

akka-stream-tests/src/test/scala/akka/stream/io/TcpSpec.scala

@@ -413,7 +413,9 @@ class TcpSpec extends StreamSpec("akka.stream.materializer.subscription-timeout.
 
       result.failed.futureValue shouldBe a[StreamTcpException]
 
-      binding.map(_.unbind()).recover { case NonFatal(_) ⇒ () } foreach (_ ⇒ system2.shutdown())
+      binding.map(_.unbind()).recover { case NonFatal(_) ⇒ () }.foreach { _ ⇒
+        shutdown(system2)
+      }
     }
 
   }

project/MiMa.scala

@@ -238,6 +238,16 @@ object MiMa extends AutoPlugin {
       // object akka.stream.stage.StatefulStage#Finish does not have a correspondent in current version
       ProblemFilters.exclude[MissingClassProblem]("akka.stream.stage.StatefulStage$Finish$"),
 
+      // #21423 remove deprecated ActorSystem termination methods (in 2.5.x)
+      ProblemFilters.exclude[DirectMissingMethodProblem]("akka.actor.ActorSystemImpl.shutdown"),
+      ProblemFilters.exclude[DirectMissingMethodProblem]("akka.actor.ActorSystemImpl.isTerminated"),
+      ProblemFilters.exclude[DirectMissingMethodProblem]("akka.actor.ActorSystemImpl.awaitTermination"),
+      ProblemFilters.exclude[DirectMissingMethodProblem]("akka.actor.ActorSystemImpl.awaitTermination"),
+      ProblemFilters.exclude[DirectMissingMethodProblem]("akka.actor.ActorSystem.shutdown"),
+      ProblemFilters.exclude[DirectMissingMethodProblem]("akka.actor.ActorSystem.isTerminated"),
+      ProblemFilters.exclude[DirectMissingMethodProblem]("akka.actor.ActorSystem.awaitTermination"),
+      ProblemFilters.exclude[DirectMissingMethodProblem]("akka.actor.ActorSystem.awaitTermination"),
+      
       // #21423 removal of deprecated `PersistentView` (in 2.5.x)
       ProblemFilters.exclude[MissingClassProblem]("akka.persistence.Update"),
       ProblemFilters.exclude[MissingClassProblem]("akka.persistence.Update$"),