Eventsource perf (#1383)

* Added perf test for ActivityStarted event.

* Moved ActivityStarted & ActivityStopped events behind an IsEnabled check.

Co-authored-by: Cijo Thomas <cithomas@microsoft.com>

src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs

@@ -17,9 +17,9 @@
 using System;
 #if DEBUG
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Linq;
 #endif
+using System.Diagnostics;
 using System.Diagnostics.Tracing;
 
 namespace OpenTelemetry.Internal
@@ -89,6 +89,24 @@ namespace OpenTelemetry.Internal
             }
         }
 
+        [NonEvent]
+        public void ActivityStarted(Activity activity)
+        {
+            if (this.IsEnabled(EventLevel.Verbose, (EventKeywords)(-1)))
+            {
+                this.ActivityStarted(activity.OperationName, activity.Id);
+            }
+        }
+
+        [NonEvent]
+        public void ActivityStopped(Activity activity)
+        {
+            if (this.IsEnabled(EventLevel.Verbose, (EventKeywords)(-1)))
+            {
+                this.ActivityStopped(activity.OperationName, activity.Id);
+            }
+        }
+
         [Event(1, Message = "Span processor queue size reached maximum. Throttling spans.", Level = EventLevel.Warning)]
         public void SpanProcessorQueueIsExhausted()
         {

src/OpenTelemetry/Trace/ActivitySourceAdapter.cs

@@ -77,7 +77,7 @@ namespace OpenTelemetry.Trace
         [System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods", Justification = "ActivityProcessor is hot path")]
         public void Start(Activity activity, ActivityKind kind)
         {
-            OpenTelemetrySdkEventSource.Log.ActivityStarted(activity.OperationName, activity.Id);
+            OpenTelemetrySdkEventSource.Log.ActivityStarted(activity);
 
             SetKindProperty(activity, kind);
             this.getRequestedDataAction(activity);
@@ -94,7 +94,7 @@ namespace OpenTelemetry.Trace
         /// <param name="activity"><see cref="Activity"/> to be stopped.</param>
         public void Stop(Activity activity)
         {
-            OpenTelemetrySdkEventSource.Log.ActivityStopped(activity.OperationName, activity.Id);
+            OpenTelemetrySdkEventSource.Log.ActivityStopped(activity);
 
             if (activity?.IsAllDataRequested ?? false)
             {

src/OpenTelemetry/Trace/TracerProviderSdk.cs

@@ -69,7 +69,7 @@ namespace OpenTelemetry.Trace
                 // Callback when Activity is started.
                 ActivityStarted = (activity) =>
                 {
-                    OpenTelemetrySdkEventSource.Log.ActivityStarted(activity.OperationName, activity.Id);
+                    OpenTelemetrySdkEventSource.Log.ActivityStarted(activity);
 
                     if (!activity.IsAllDataRequested)
                     {
@@ -86,7 +86,7 @@ namespace OpenTelemetry.Trace
                 // Callback when Activity is stopped.
                 ActivityStopped = (activity) =>
                 {
-                    OpenTelemetrySdkEventSource.Log.ActivityStopped(activity.OperationName, activity.Id);
+                    OpenTelemetrySdkEventSource.Log.ActivityStopped(activity);
 
                     if (!activity.IsAllDataRequested)
                     {

test/Benchmarks/EventSourceBenchmarks.cs

@@ -0,0 +1,48 @@
+// <copyright file="EventSourceBenchmarks.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+using System.Diagnostics;
+using BenchmarkDotNet.Attributes;
+using OpenTelemetry.Internal;
+
+namespace OpenTelemetry.Benchmarks
+{
+    [MemoryDiagnoser]
+    public class EventSourceBenchmarks
+    {
+        [Benchmark]
+        public void EventWithIdAllocation()
+        {
+            Activity activity = new Activity("TestActivity");
+            activity.SetIdFormat(ActivityIdFormat.W3C);
+            activity.Start();
+            activity.Stop();
+
+            OpenTelemetrySdkEventSource.Log.ActivityStarted(activity.OperationName, activity.Id);
+        }
+
+        [Benchmark]
+        public void EventWithCheck()
+        {
+            Activity activity = new Activity("TestActivity");
+            activity.SetIdFormat(ActivityIdFormat.W3C);
+            activity.Start();
+            activity.Stop();
+
+            OpenTelemetrySdkEventSource.Log.ActivityStarted(activity);
+        }
+    }
+}