Switch to IServiceProvidersFeature for RequestServices

src/Microsoft.AspNet.Hosting/Internal/RequestServicesContainerFeature.cs

@@ -0,0 +1,70 @@
+// 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 Microsoft.AspNet.Http.Features.Internal;
+using Microsoft.Framework.DependencyInjection;
+
+namespace Microsoft.AspNet.Hosting.Internal
+{
+    public class RequestServicesFeature : IServiceProvidersFeature, IDisposable
+    {
+        private IServiceProvider _appServices;
+        private IServiceProvider _requestServices;
+        private IServiceScope _scope;
+        private bool _requestServicesSet;
+
+        public RequestServicesFeature(IServiceProvider applicationServices)
+        {
+            if (applicationServices == null)
+            {
+                throw new ArgumentNullException(nameof(applicationServices));
+            }
+
+            ApplicationServices = applicationServices;
+        }
+
+        public IServiceProvider ApplicationServices
+        {
+            get
+            {
+                return _appServices;
+            }
+            set
+            {
+                if (value == null)
+                {
+                    throw new ArgumentNullException(nameof(value));
+                }
+                _appServices = value;
+            }
+        }
+
+        public IServiceProvider RequestServices
+        {
+            get
+            {
+                if (!_requestServicesSet)
+                {
+                    _scope = ApplicationServices.GetRequiredService<IServiceScopeFactory>().CreateScope();
+                    _requestServices = _scope.ServiceProvider;
+                    _requestServicesSet = true;
+                }
+                return _requestServices;
+            }
+
+            set
+            {
+                _requestServicesSet = true;
+                RequestServices = value;
+            }
+        }
+
+        public void Dispose()
+        {
+            _scope?.Dispose();
+            _scope = null;
+            _requestServices = null;
+        }
+    }
+}

src/Microsoft.AspNet.Hosting/Internal/RequestServicesContainerMiddleware.cs

@@ -5,6 +5,8 @@ using System;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Http;
+using Microsoft.AspNet.Http.Features;
+using Microsoft.AspNet.Http.Features.Internal;
 using Microsoft.Framework.DependencyInjection;
 
 namespace Microsoft.AspNet.Hosting.Internal
@@ -20,7 +22,6 @@ namespace Microsoft.AspNet.Hosting.Internal
             {
                 throw new ArgumentNullException(nameof(next));
             }
-
             if (services == null)
             {
                 throw new ArgumentNullException(nameof(services));
@@ -37,32 +38,26 @@ namespace Microsoft.AspNet.Hosting.Internal
                 throw new ArgumentNullException(nameof(httpContext));
             }
 
-            // All done if there request services is set
+            var existingFeature = httpContext.Features.Get<IServiceProvidersFeature>();
-            if (httpContext.RequestServices != null)
+
+            // All done if request services is set
+            if (existingFeature?.RequestServices != null)
             {
                 await _next.Invoke(httpContext);
                 return;
             }
 
-            var priorApplicationServices = httpContext.ApplicationServices;
+            using (var feature = new RequestServicesFeature(_services))
-            var serviceProvider = priorApplicationServices ?? _services;
-            var scopeFactory = serviceProvider.GetRequiredService<IServiceScopeFactory>();
-
-            try
             {
-                // Creates the scope and temporarily swap services
+                try
-                using (var scope = scopeFactory.CreateScope())
                 {
-                    httpContext.ApplicationServices = serviceProvider;
+                    httpContext.Features.Set<IServiceProvidersFeature>(feature);
-                    httpContext.RequestServices = scope.ServiceProvider;
-
                     await _next.Invoke(httpContext);
                 }
-            }
+                finally
-            finally
+                {
-            {
+                    httpContext.Features.Set(existingFeature);
-                httpContext.RequestServices = null;
+                }
-                httpContext.ApplicationServices = priorApplicationServices;
             }
         }
     }

test/Microsoft.AspNet.TestHost.Tests/TestServerTests.cs

@@ -11,6 +11,8 @@ using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Hosting;
 using Microsoft.AspNet.Hosting.Startup;
 using Microsoft.AspNet.Http;
+using Microsoft.AspNet.Http.Features;
+using Microsoft.AspNet.Http.Features.Internal;
 using Microsoft.Framework.Configuration;
 using Microsoft.Framework.DependencyInjection;
 using Microsoft.Framework.Logging;
@@ -133,6 +135,103 @@ namespace Microsoft.AspNet.TestHost
             Assert.Equal("Found:True", result);
         }
 
+        [Fact]
+        public async Task SettingApplicationServicesOnFeatureToNullThrows()
+        {
+            var server = TestServer.Create(app =>
+            {
+                app.Run(context =>
+                {
+                    var feature = context.Features.Get<IServiceProvidersFeature>();
+                    Assert.Throws<ArgumentNullException>(() => feature.ApplicationServices = null);
+                    return context.Response.WriteAsync("Success");
+                });
+            });
+            string result = await server.CreateClient().GetStringAsync("/path");
+            Assert.Equal("Success", result);
+        }
+
+        public class ReplaceServiceProvidersFeatureFilter : IStartupFilter, IServiceProvidersFeature
+        {
+            public ReplaceServiceProvidersFeatureFilter(IServiceProvider appServices, IServiceProvider requestServices)
+            {
+                ApplicationServices = appServices;
+                RequestServices = requestServices;
+            }
+
+            public IServiceProvider ApplicationServices { get; set; }
+
+            public IServiceProvider RequestServices { get; set; }
+
+            public Action<IApplicationBuilder> Configure(Action<IApplicationBuilder> next)
+            {
+                return app =>
+                {
+                    app.Use(async (context, nxt) =>
+                    {
+                        context.Features.Set<IServiceProvidersFeature>(this);
+                        await nxt();
+                    });
+                    next(app);
+                };
+            }
+        }
+
+        [Fact]
+        public async Task ExistingServiceProviderFeatureWillNotBeReplaced()
+        {
+            var appServices = new ServiceCollection().BuildServiceProvider();
+            var server = TestServer.Create(app =>
+            {
+                app.Run(context =>
+                {
+                    Assert.Equal(appServices, context.ApplicationServices);
+                    Assert.Equal(appServices, context.RequestServices);
+                    return context.Response.WriteAsync("Success");
+                });
+            },
+            services => services.AddInstance<IStartupFilter>(new ReplaceServiceProvidersFeatureFilter(appServices, appServices)));
+            var result = await server.CreateClient().GetStringAsync("/path");
+            Assert.Equal("Success", result);
+        }
+
+        public class NullServiceProvidersFeatureFilter : IStartupFilter, IServiceProvidersFeature
+        {
+            public IServiceProvider ApplicationServices { get; set; }
+
+            public IServiceProvider RequestServices { get; set; }
+
+            public Action<IApplicationBuilder> Configure(Action<IApplicationBuilder> next)
+            {
+                return app =>
+                {
+                    app.Use(async (context, nxt) =>
+                    {
+                        context.Features.Set<IServiceProvidersFeature>(this);
+                        await nxt();
+                    });
+                    next(app);
+                };
+            }
+        }
+
+        [Fact]
+        public async Task WillReplaceServiceProviderFeatureWithNullRequestServices()
+        {
+            var server = TestServer.Create(app =>
+            {
+                app.Run(context =>
+                {
+                    Assert.NotNull(context.ApplicationServices);
+                    Assert.NotNull(context.RequestServices);
+                    return context.Response.WriteAsync("Success");
+                });
+            },
+            services => services.AddTransient<IStartupFilter, NullServiceProvidersFeatureFilter>());
+            var result = await server.CreateClient().GetStringAsync("/path");
+            Assert.Equal("Success", result);
+        }
+
         public class EnsureApplicationServicesFilter : IStartupFilter
         {
             public Action<IApplicationBuilder> Configure(Action<IApplicationBuilder> next)