added EventStreamBenchmark (#6405)

src/benchmark/Akka.Benchmarks/EventStream/EventStreamBenchmarks.cs

@@ -0,0 +1,57 @@
+//-----------------------------------------------------------------------
+// <copyright file="EventStreamBenchmarks.cs" company="Akka.NET Project">
+//     Copyright (C) 2009-2023 Lightbend Inc. <http://www.lightbend.com>
+//     Copyright (C) 2013-2023 .NET Foundation <https://github.com/akkadotnet/akka.net>
+// </copyright>
+//-----------------------------------------------------------------------
+
+using Akka.Actor;
+using Akka.Benchmarks.Configurations;
+using BenchmarkDotNet.Attributes;
+
+namespace Akka.Benchmarks.EventStream
+{
+    [Config(typeof(MicroBenchmarkConfig))]
+    public class EventStreamBenchmarks
+    {
+
+        public const int NumOperations = 1_000_000;
+
+        internal sealed class FakeActor : MinimalActorRef
+        {
+            public override ActorPath Path { get; } = new RootActorPath(new Address("akka", "test")) / "fake";
+            public override IActorRefProvider Provider => throw new System.NotImplementedException();
+
+            public int LastMessage { get; private set; }
+
+            protected override void TellInternal(object message, IActorRef sender)
+            {
+                LastMessage++;
+            }
+        }
+
+        private FakeActor _fakeActor;
+        private Akka.Event.EventStream _eventStream;
+
+        private const string _msg = "foo";
+
+
+        [IterationSetup]
+        public void InitLogger()
+        {
+            _eventStream = new Event.EventStream(false);
+            _fakeActor = new FakeActor();
+            _eventStream.Subscribe(_fakeActor, typeof(string));
+        }
+
+        [Benchmark(OperationsPerInvoke = NumOperations)]
+        public object Publish()
+        {
+            for (var i = 0; i < NumOperations; i++)
+            {
+                _eventStream.Publish(_msg);
+            }
+            return _fakeActor.LastMessage;
+        }
+    }
+}