Added EventSource to Hosting

Author: kichalla

src/Microsoft.AspNetCore.Hosting/Internal/HostingApplication.cs

@@ -43,6 +43,8 @@ public Context CreateContext(IFeatureCollection contextFeatures)
                 _diagnosticSource.Write("Microsoft.AspNetCore.Hosting.BeginRequest", new { httpContext = httpContext, timestamp = startTimestamp });
             }
 
+            HostingEventSource.Log.RequestStart(httpContext);
+
             return new Context
             {
                 HttpContext = httpContext,
@@ -66,6 +68,8 @@ public void DisposeContext(Context context, Exception exception)
                 {
                     _diagnosticSource.Write("Microsoft.AspNetCore.Hosting.EndRequest", new { httpContext = httpContext, timestamp = currentTimestamp });
                 }
+
+                HostingEventSource.Log.RequestStop(httpContext);
             }
             else
             {
@@ -78,6 +82,8 @@ public void DisposeContext(Context context, Exception exception)
                 {
                     _diagnosticSource.Write("Microsoft.AspNetCore.Hosting.UnhandledException", new { httpContext = httpContext, timestamp = currentTimestamp, exception = exception });
                 }
+
+                HostingEventSource.Log.RequestStop(httpContext, exception);
             }
 
             context.Scope?.Dispose();

src/Microsoft.AspNetCore.Hosting/Internal/HostingEventSource.cs

@@ -0,0 +1,94 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Diagnostics.Tracing;
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Hosting.Internal
+{
+    [EventSource(Name = "Microsoft-AspNetCore-Hosting")]
+    public sealed class HostingEventSource : EventSource
+    {
+        public static readonly HostingEventSource Log = new HostingEventSource();
+
+        private HostingEventSource() { }
+
+        [Event(1, Level = EventLevel.Informational)]
+        public void HostStart()
+        {
+            WriteEvent(1);
+        }
+
+        [Event(2, Level = EventLevel.Informational)]
+        public void HostStop()
+        {
+            WriteEvent(2);
+        }
+
+        [NonEvent]
+        public void RequestStart(HttpContext context)
+        {
+            if (IsEnabled())
+            {
+                RequestStart(
+                    context.TraceIdentifier,
+                    context.Request.Protocol,
+                    context.Request.Method,
+                    context.Request.ContentType ?? string.Empty,
+                    context.Request.ContentLength.HasValue ? context.Request.ContentLength.Value.ToString() : string.Empty,
+                    context.Request.Scheme,
+                    context.Request.Host.ToString(),
+                    context.Request.PathBase,
+                    context.Request.Path,
+                    context.Request.QueryString.ToString());
+            }
+        }
+
+        [NonEvent]
+        public void RequestStop(HttpContext context, Exception exception = null)
+        {
+            if (IsEnabled())
+            {
+                RequestStop(
+                    context.Response.StatusCode,
+                    context.Response.ContentType ?? string.Empty,
+                    context.TraceIdentifier,
+                    exception == null ? string.Empty : exception.ToString());
+            }
+        }
+
+        [Event(3, Level = EventLevel.Informational)]
+        public void RequestStart(
+            string requestTraceIdentifier,
+            string protocol,
+            string method,
+            string contentType,
+            string contentLength,
+            string scheme,
+            string host,
+            string pathBase,
+            string path,
+            string queryString)
+        {
+            WriteEvent(
+                3,
+                requestTraceIdentifier,
+                protocol,
+                method,
+                contentType,
+                contentLength,
+                scheme,
+                host,
+                pathBase,
+                path,
+                queryString);
+        }
+
+        [Event(4, Level = EventLevel.Informational)]
+        private void RequestStop(int statusCode, string contentType, string requestTraceIdentifier, string exception)
+        {
+            WriteEvent(4, statusCode, contentType, requestTraceIdentifier, exception);
+        }
+    }
+}

src/Microsoft.AspNetCore.Hosting/Internal/WebHost.cs

@@ -99,6 +99,8 @@ public void Initialize()
 
         public virtual void Start()
         {
+            HostingEventSource.Log.HostStart();
+
             Initialize();
 
             _logger = _applicationServices.GetRequiredService<ILogger<WebHost>>();
@@ -248,6 +250,8 @@ public void Dispose()
             (_hostingServiceProvider as IDisposable)?.Dispose();
             (_applicationServices as IDisposable)?.Dispose();
             _applicationLifetime.NotifyStopped();
+
+            HostingEventSource.Log.HostStop();
         }
     }
 }