Add convenience method to start timer without key (akka#27875)

* Add convenience method to start timer without key

It is probably common that there is no need to allow different timers
that send the same message, and this makes that more convenient to write.

Updated one method to gather feedback, if we like the change I can apply
it to the others as well.

* Add alternative to all typed timer API's

Update java/scaladoc, update tests

Not updated classic actors and FSM API's

akka-actor-testkit-typed/src/test/java/jdocs/akka/actor/testkit/typed/javadsl/ManualTimerExampleTest.java

@@ -30,7 +30,11 @@ public class ManualTimerExampleTest extends JUnitSuite {
 
   private final ManualTime manualTime = ManualTime.get(testKit.system());
 
-  static final class Tick {}
+  static final class Tick {
+    private Tick() {}
+
+    static final Tick INSTANCE = new Tick();
+  }
 
   static final class Tock {}
 
@@ -40,7 +44,7 @@ public void testScheduleNonRepeatedTicks() {
     Behavior<Tick> behavior =
         Behaviors.withTimers(
             timer -> {
-              timer.startSingleTimer("T", new Tick(), Duration.ofMillis(10));
+              timer.startSingleTimer(Tick.INSTANCE, Duration.ofMillis(10));
               return Behaviors.receiveMessage(
                   tick -> {
                     probe.ref().tell(new Tock());

akka-actor-testkit-typed/src/test/scala/akka/actor/testkit/typed/scaladsl/TestProbeSpec.scala

@@ -47,7 +47,7 @@ class TestProbeSpec extends ScalaTestWithActorTestKit with WordSpecLike with Log
       val probe = TestProbe()
       val ref = spawn(Behaviors.receive[Stop.type]((_, _) =>
         Behaviors.withTimers { timer =>
-          timer.startSingleTimer("key", Stop, 300.millis)
+          timer.startSingleTimer(Stop, 300.millis)
 
           Behaviors.receive((_, _) => Behaviors.stopped)
         }))

akka-actor-testkit-typed/src/test/scala/docs/akka/actor/testkit/typed/scaladsl/ManualTimerExampleSpec.scala

@@ -25,7 +25,7 @@ class ManualTimerExampleSpec extends ScalaTestWithActorTestKit(ManualTime.config
 
       val probe = TestProbe[Tock.type]()
       val behavior = Behaviors.withTimers[Tick.type] { timer =>
-        timer.startSingleTimer("T", Tick, 10.millis)
+        timer.startSingleTimer(Tick, 10.millis)
         Behaviors.receiveMessage { _ =>
           probe.ref ! Tock
           Behaviors.same
@@ -49,7 +49,7 @@ class ManualTimerExampleSpec extends ScalaTestWithActorTestKit(ManualTime.config
 
       val probe = TestProbe[Tock.type]()
       val behavior = Behaviors.withTimers[Tick.type] { timer =>
-        timer.startTimerWithFixedDelay("T", Tick, 10.millis)
+        timer.startTimerWithFixedDelay(Tick, 10.millis)
         Behaviors.receiveMessage { _ =>
           probe.ref ! Tock
           Behaviors.same

akka-actor-typed-tests/src/test/java/akka/actor/typed/javadsl/ActorCompile.java

@@ -133,6 +133,15 @@ public Behavior<MyMsg> aroundSignal(
             });
   }
 
+  {
+    Behavior<MyMsg> b =
+        Behaviors.withTimers(
+            timers -> {
+              timers.startTimerWithFixedDelay(new MyMsgB("tick"), Duration.ofSeconds(1));
+              return Behaviors.ignore();
+            });
+  }
+
   static class MyBehavior extends ExtensibleBehavior<MyMsg> {
 
     @Override

akka-actor-typed-tests/src/test/java/jdocs/akka/typed/StyleGuideDocExamples.java

@@ -211,7 +211,7 @@ private static Behavior<Command> onIncrementRepeatedly(
                 name,
                 command.interval,
                 n);
-        timers.startTimerWithFixedDelay("repeat", Increment.INSTANCE, command.interval);
+        timers.startTimerWithFixedDelay(Increment.INSTANCE, command.interval);
         return Behaviors.same();
       }
 
@@ -306,7 +306,7 @@ private static Behavior<Command> onIncrementRepeatedly(
                 setup.name,
                 command.interval,
                 n);
-        setup.timers.startTimerWithFixedDelay("repeat", Increment.INSTANCE, command.interval);
+        setup.timers.startTimerWithFixedDelay(Increment.INSTANCE, command.interval);
         return Behaviors.same();
       }
 
@@ -394,7 +394,7 @@ private Behavior<Command> onIncrementRepeatedly(int n, IncrementRepeatedly comma
                 name,
                 command.interval,
                 n);
-        timers.startTimerWithFixedDelay("repeat", Increment.INSTANCE, command.interval);
+        timers.startTimerWithFixedDelay(Increment.INSTANCE, command.interval);
         return Behaviors.same();
       }
 
@@ -552,7 +552,7 @@ public static Behavior<Command> create(String name, Duration tickInterval) {
             context ->
                 Behaviors.withTimers(
                     timers -> {
-                      timers.startTimerWithFixedDelay("tick", Tick.INSTANCE, tickInterval);
+                      timers.startTimerWithFixedDelay(Tick.INSTANCE, tickInterval);
                       return new Counter(name, context);
                     }));
       }
@@ -688,7 +688,7 @@ public static Behavior<Command> create(String name, Duration tickInterval) {
                 (ActorContext<Message> context) ->
                     Behaviors.withTimers(
                         timers -> {
-                          timers.startTimerWithFixedDelay("tick", Tick.INSTANCE, tickInterval);
+                          timers.startTimerWithFixedDelay(Tick.INSTANCE, tickInterval);
                           return new Counter(name, context);
                         }))
             .narrow(); // note narrow here

akka-actor-typed-tests/src/test/scala/akka/actor/typed/TimerSpec.scala

@@ -88,7 +88,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
     "schedule non-repeated ticks" taggedAs TimingTest in {
       val probe = TestProbe[Event]("evt")
       val behv = Behaviors.withTimers[Command] { timer =>
-        timer.startSingleTimer("T", Tick(1), 10.millis)
+        timer.startSingleTimer(Tick(1), 10.millis)
         target(probe.ref, timer, 1)
       }
 
@@ -103,7 +103,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
     "schedule repeated ticks" taggedAs TimingTest in {
       val probe = TestProbe[Event]("evt")
       val behv = Behaviors.withTimers[Command] { timer =>
-        timer.startTimerWithFixedDelay("T", Tick(1), interval)
+        timer.startTimerWithFixedDelay(Tick(1), interval)
         target(probe.ref, timer, 1)
       }
 
@@ -121,7 +121,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
     "replace timer" taggedAs TimingTest in {
       val probe = TestProbe[Event]("evt")
       val behv = Behaviors.withTimers[Command] { timer =>
-        timer.startTimerWithFixedDelay("T", Tick(1), interval)
+        timer.startTimerWithFixedDelay(Tick(1), interval)
         target(probe.ref, timer, 1)
       }
 
@@ -141,7 +141,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
     "cancel timer" taggedAs TimingTest in {
       val probe = TestProbe[Event]("evt")
       val behv = Behaviors.withTimers[Command] { timer =>
-        timer.startTimerWithFixedDelay("T", Tick(1), interval)
+        timer.startTimerWithFixedDelay(Tick(1), interval)
         target(probe.ref, timer, 1)
       }
 
@@ -193,7 +193,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
       val probe = TestProbe[Event]("evt")
       val behv = Behaviors
         .supervise(Behaviors.withTimers[Command] { timer =>
-          timer.startTimerWithFixedDelay("T", Tick(1), interval)
+          timer.startTimerWithFixedDelay(Tick(1), interval)
           target(probe.ref, timer, 1)
         })
         .onFailure[Exception](SupervisorStrategy.restart)
@@ -222,7 +222,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
     "cancel timers when stopped from exception" taggedAs TimingTest in {
       val probe = TestProbe[Event]()
       val behv = Behaviors.withTimers[Command] { timer =>
-        timer.startTimerWithFixedDelay("T", Tick(1), interval)
+        timer.startTimerWithFixedDelay(Tick(1), interval)
         target(probe.ref, timer, 1)
       }
       val ref = spawn(behv)
@@ -235,7 +235,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
     "cancel timers when stopped voluntarily" taggedAs TimingTest in {
       val probe = TestProbe[Event]()
       val behv = Behaviors.withTimers[Command] { timer =>
-        timer.startTimerWithFixedDelay("T", Tick(1), interval)
+        timer.startTimerWithFixedDelay(Tick(1), interval)
         target(probe.ref, timer, 1)
       }
       val ref = spawn(behv)
@@ -246,9 +246,9 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
     "allow for nested timers" in {
       val probe = TestProbe[String]()
       val ref = spawn(Behaviors.withTimers[String] { outerTimer =>
-        outerTimer.startTimerWithFixedDelay("outer-key", "outer-message", 50.millis)
+        outerTimer.startTimerWithFixedDelay("outer-message", 50.millis)
         Behaviors.withTimers { innerTimer =>
-          innerTimer.startTimerWithFixedDelay("inner-key", "inner-message", 50.millis)
+          innerTimer.startTimerWithFixedDelay("inner-message", 50.millis)
           Behaviors.receiveMessage { message =>
             if (message == "stop") Behaviors.stopped
             else {
@@ -273,7 +273,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
     "keep timers when behavior changes" in {
       val probe = TestProbe[String]()
       def newBehavior(n: Int): Behavior[String] = Behaviors.withTimers[String] { timers =>
-        timers.startTimerWithFixedDelay(s"key${n}", s"message${n}", 50.milli)
+        timers.startTimerWithFixedDelay(s"message${n}", 50.milli)
         Behaviors.receiveMessage { message =>
           if (message == "stop") Behaviors.stopped
           else {
@@ -299,7 +299,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
       val probe = TestProbe[DeadLetter]()
       val ref = spawn(Behaviors.withTimers[String] { timers =>
         Behaviors.setup { _ =>
-          timers.startTimerWithFixedDelay("test", "test", 250.millis)
+          timers.startTimerWithFixedDelay("test", 250.millis)
           Behaviors.receive { (context, _) =>
             Behaviors.stopped(() => context.log.info(s"stopping"))
           }
@@ -323,11 +323,11 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
         case Tick(-1) =>
           probe.ref ! Tock(-1)
           Behaviors.withTimers[Command] { timer =>
-            timer.startSingleTimer("T0", Tick(0), 5.millis)
+            timer.startSingleTimer(Tick(0), 5.millis)
             Behaviors.receiveMessage[Command] {
               case Tick(0) =>
                 probe.ref ! Tock(0)
-                timer.startSingleTimer("T1", Tick(1), 5.millis)
+                timer.startSingleTimer(Tick(1), 5.millis)
                 // let Tick(0) arrive in mailbox, test will not fail if it arrives later
                 Thread.sleep(100)
                 throw TestException("boom")
@@ -365,7 +365,7 @@ class TimerSpec extends ScalaTestWithActorTestKit with WordSpecLike with LogCapt
       case Tick(-1) =>
         probe.ref ! Tock(-1)
         Behaviors.withTimers[Command] { timer =>
-          timer.startSingleTimer("T0", Tick(0), 5.millis)
+          timer.startSingleTimer(Tick(0), 5.millis)
           // let Tick(0) arrive in mailbox, test will not fail if it arrives later
           Thread.sleep(100)
           throw TestException("boom")

akka-actor-typed-tests/src/test/scala/akka/actor/typed/TransformMessagesSpec.scala

@@ -148,7 +148,7 @@ class TransformMessagesSpec extends ScalaTestWithActorTestKit with WordSpecLike
       val probe = TestProbe[String]()
       val behv = Behaviors
         .withTimers[String] { timers =>
-          timers.startSingleTimer("timer", "a", 10.millis)
+          timers.startSingleTimer("a", 10.millis)
           Behaviors.receiveMessage { msg =>
             probe.ref ! msg
             Behaviors.same
@@ -169,7 +169,7 @@ class TransformMessagesSpec extends ScalaTestWithActorTestKit with WordSpecLike
     "be possible to combine with outer timers" in {
       val probe = TestProbe[String]()
       val behv = Behaviors.withTimers[String] { timers =>
-        timers.startSingleTimer("timer", "a", 10.millis)
+        timers.startSingleTimer("a", 10.millis)
         Behaviors
           .receiveMessage[String] { msg =>
             probe.ref ! msg

akka-actor-typed-tests/src/test/scala/docs/akka/typed/FSMDocSpec.scala

@@ -57,7 +57,7 @@ object FSMDocSpec {
     private def active(data: Todo): Behavior[Event] =
       Behaviors.withTimers[Event] { timers =>
         // instead of FSM state timeout
-        timers.startSingleTimer(Timeout, Timeout, 1.second)
+        timers.startSingleTimer(Timeout, 1.second)
         Behaviors.receiveMessagePartial {
           case Flush | Timeout =>
             data.target ! Batch(data.queue)

akka-actor-typed-tests/src/test/scala/docs/akka/typed/StyleGuideDocExamples.scala

@@ -123,7 +123,7 @@ object StyleGuideDocExamples {
                 name,
                 interval.toString,
                 n.toString)
-              timers.startTimerWithFixedDelay("repeat", Increment, interval)
+              timers.startTimerWithFixedDelay(Increment, interval)
               Behaviors.same
             case Increment =>
               val newValue = n + 1
@@ -166,7 +166,7 @@ object StyleGuideDocExamples {
               setup.name,
               interval,
               n)
-            setup.timers.startTimerWithFixedDelay("repeat", Increment, interval)
+            setup.timers.startTimerWithFixedDelay(Increment, interval)
             Behaviors.same
           case Increment =>
             val newValue = n + 1
@@ -213,7 +213,7 @@ object StyleGuideDocExamples {
               name,
               interval,
               n)
-            timers.startTimerWithFixedDelay("repeat", Increment, interval)
+            timers.startTimerWithFixedDelay(Increment, interval)
             Behaviors.same
           case Increment =>
             val newValue = n + 1
@@ -249,7 +249,7 @@ object StyleGuideDocExamples {
                     name,
                     interval,
                     n)
-                  timers.startTimerWithFixedDelay("repeat", Increment, interval)
+                  timers.startTimerWithFixedDelay(Increment, interval)
                   Behaviors.same
                 case Increment =>
                   val newValue = n + 1
@@ -341,7 +341,7 @@ object StyleGuideDocExamples {
       def apply(name: String, tickInterval: FiniteDuration): Behavior[Command] =
         Behaviors.setup { context =>
           Behaviors.withTimers { timers =>
-            timers.startTimerWithFixedDelay("tick", Tick, tickInterval)
+            timers.startTimerWithFixedDelay(Tick, tickInterval)
             new Counter(name, context).counter(0)
           }
         }
@@ -390,7 +390,7 @@ object StyleGuideDocExamples {
         Behaviors
           .setup[Counter.Message] { context =>
             Behaviors.withTimers { timers =>
-              timers.startTimerWithFixedDelay("tick", Tick, tickInterval)
+              timers.startTimerWithFixedDelay(Tick, tickInterval)
               new Counter(name, context).counter(0)
             }
           }

akka-actor-typed-tests/src/test/scala/docs/akka/typed/TailChopping.scala

@@ -46,9 +46,9 @@ object TailChopping {
 
         def sendNextRequest(requestCount: Int): Behavior[Command] = {
           if (sendRequest(requestCount, replyAdapter)) {
-            timers.startSingleTimer(RequestTimeout, RequestTimeout, nextRequestAfter)
+            timers.startSingleTimer(RequestTimeout, nextRequestAfter)
           } else {
-            timers.startSingleTimer(FinalTimeout, FinalTimeout, finalTimeout)
+            timers.startSingleTimer(FinalTimeout, finalTimeout)
           }
           waiting(requestCount)
         }