4.x: Additional benchmarks for comparison

Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/Benchmarks.System.Reactive.csproj

@@ -21,6 +21,7 @@
 
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" Version="0.10.14" />
+    <PackageReference Include="WindowsBase" Version="4.6.1055" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(Configuration)|$(Platform)'=='Rx.net 3.1.1|AnyCPU'">
@@ -35,4 +36,8 @@
     <ProjectReference Include="..\..\tests\Tests.System.Reactive\Tests.System.Reactive.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Reference Include="System.Windows.Forms" />
+  </ItemGroup>
+
 </Project>

Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/ComparisonAsyncBenchmark.cs

@@ -0,0 +1,87 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Linq;
+using System.Reactive.Concurrency;
+using System.Reactive.Linq;
+using System.Threading;
+using BenchmarkDotNet.Attributes;
+
+namespace Benchmarks.System.Reactive
+{
+    [MemoryDiagnoser]
+    public class ComparisonAsyncBenchmark
+    {
+        [Params(1, 10, 100, 1000, 10000, 100000, 1000000)]
+        public int N;
+        private int _store;
+
+        IScheduler _scheduler1;
+        IScheduler _scheduler2;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            _scheduler1 = new EventLoopScheduler();
+            _scheduler2 = new EventLoopScheduler();
+        }
+
+        [Benchmark]
+        public void ObserveOn()
+        {
+            var cde = new CountdownEvent(1);
+
+            Observable.Range(1, N).ObserveOn(_scheduler1)
+                .Subscribe(v => Volatile.Write(ref _store, v), () => cde.Signal());
+
+            if (N <= 1000)
+            {
+                while (cde.CurrentCount != 0) ;
+            }
+            else
+            {
+                cde.Wait();
+            }
+        }
+
+        [Benchmark]
+        public void SubscribeOn()
+        {
+            var cde = new CountdownEvent(1);
+
+            Observable.Range(1, N).SubscribeOn(_scheduler1)
+                .Subscribe(v => Volatile.Write(ref _store, v), () => cde.Signal());
+
+            if (N <= 1000)
+            {
+                while (cde.CurrentCount != 0) ;
+            }
+            else
+            {
+                cde.Wait();
+            }
+        }
+
+        [Benchmark]
+        public void SubscribeOnObserveOn()
+        {
+            var cde = new CountdownEvent(1);
+
+            Observable.Range(1, N)
+                .SubscribeOn(_scheduler1)
+                .ObserveOn(_scheduler2)
+                .Subscribe(v => Volatile.Write(ref _store, v), () => cde.Signal());
+
+            if (N <= 1000)
+            {
+                while (cde.CurrentCount != 0) ;
+            }
+            else
+            {
+                cde.Wait();
+            }
+        }
+    }
+}