Disable AllowSynchronousIO by default in all servers #4774

src/Hosting/TestHost/src/TestServer.cs

@@ -81,9 +81,9 @@ public IWebHost Host
         /// Gets or sets a value that controls whether synchronous IO is allowed for the <see cref="HttpContext.Request"/> and <see cref="HttpContext.Response"/>
         /// </summary>
         /// <remarks>
-        /// Defaults to true.
+        /// Defaults to false.
         /// </remarks>
-        public bool AllowSynchronousIO { get; set; } = true;
+        public bool AllowSynchronousIO { get; set; } = false;
 
         private IHttpApplication<Context> Application
         {

src/Servers/HttpSys/src/HttpSysOptions.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// 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;
@@ -136,9 +136,9 @@ public long? MaxRequestBodySize
 
         /// <summary>
         /// Gets or sets a value that controls whether synchronous IO is allowed for the HttpContext.Request.Body and HttpContext.Response.Body.
-        /// The default is `true`.
+        /// The default is `false`.
         /// </summary>
-        public bool AllowSynchronousIO { get; set; } = true;
+        public bool AllowSynchronousIO { get; set; } = false;
 
         /// <summary>
         /// Gets or sets a value that controls how http.sys reacts when rejecting requests due to throttling conditions - like when the request

src/Servers/HttpSys/test/FunctionalTests/Listener/RequestBodyTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// 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;
@@ -17,26 +17,26 @@ namespace Microsoft.AspNetCore.Server.HttpSys.Listener
     public class RequestBodyTests
     {
         [ConditionalFact]
-        public async Task RequestBody_SyncReadEnabledByDefault_ThrowsWhenDisabled()
+        public async Task RequestBody_SyncReadDisabledByDefault_WorksWhenEnabled()
         {
             string address;
             using (var server = Utilities.CreateHttpServer(out address))
             {
                 Task<string> responseTask = SendRequestAsync(address, "Hello World");
 
-                Assert.True(server.Options.AllowSynchronousIO);
+                Assert.False(server.Options.AllowSynchronousIO);
 
                 var context = await server.AcceptAsync(Utilities.DefaultTimeout).Before(responseTask);
                 byte[] input = new byte[100];
+                Assert.Throws<InvalidOperationException>(() => context.Request.Body.Read(input, 0, input.Length));
+
+                context.AllowSynchronousIO = true;
 
                 Assert.True(context.AllowSynchronousIO);
                 var read = context.Request.Body.Read(input, 0, input.Length);
                 context.Response.ContentLength = read;
                 context.Response.Body.Write(input, 0, read);
 
-                context.AllowSynchronousIO = false;
-                Assert.Throws<InvalidOperationException>(() => context.Request.Body.Read(input, 0, input.Length));
-
                 string response = await responseTask;
                 Assert.Equal("Hello World", response);
             }

src/Servers/HttpSys/test/FunctionalTests/Listener/ResponseBodyTests.cs

@@ -17,7 +17,7 @@ namespace Microsoft.AspNetCore.Server.HttpSys.Listener
     public class ResponseBodyTests
     {
         [ConditionalFact]
-        public async Task ResponseBody_SyncWriteEnabledByDefault_ThrowsWhenDisabled()
+        public async Task ResponseBody_SyncWriteDisabledByDefault_WorksWhenEnabled()
         {
             string address;
             using (var server = Utilities.CreateHttpServer(out address))
@@ -26,19 +26,17 @@ public async Task ResponseBody_SyncWriteEnabledByDefault_ThrowsWhenDisabled()
 
                 var context = await server.AcceptAsync(Utilities.DefaultTimeout).Before(responseTask);
 
-                Assert.True(context.AllowSynchronousIO);
-
-                context.Response.Body.Flush();
-                context.Response.Body.Write(new byte[10], 0, 10);
-                context.Response.Body.Flush();
-
-                context.AllowSynchronousIO = false;
+                Assert.False(context.AllowSynchronousIO);
 
                 Assert.Throws<InvalidOperationException>(() => context.Response.Body.Flush());
                 Assert.Throws<InvalidOperationException>(() => context.Response.Body.Write(new byte[10], 0, 10));
                 Assert.Throws<InvalidOperationException>(() => context.Response.Body.Flush());
 
-                await context.Response.Body.WriteAsync(new byte[10], 0, 10);
+                context.AllowSynchronousIO = true;
+
+                context.Response.Body.Flush();
+                context.Response.Body.Write(new byte[10], 0, 10);
+                context.Response.Body.Flush();
                 context.Dispose();
 
                 var response = await responseTask;
@@ -47,7 +45,7 @@ public async Task ResponseBody_SyncWriteEnabledByDefault_ThrowsWhenDisabled()
                 IEnumerable<string> ignored;
                 Assert.False(response.Content.Headers.TryGetValues("content-length", out ignored), "Content-Length");
                 Assert.True(response.Headers.TransferEncodingChunked.Value, "Chunked");
-                Assert.Equal(new byte[20], await response.Content.ReadAsByteArrayAsync());
+                Assert.Equal(new byte[10], await response.Content.ReadAsByteArrayAsync());
             }
         }
 
@@ -477,4 +475,4 @@ public async Task ResponseBody_ClientDisconnectsBeforeSecondWriteAsync_WriteComp
             }
         }
     }
-}
+}

src/Servers/IIS/IIS/src/Core/IISHttpContext.FeatureCollection.cs

@@ -320,7 +320,7 @@ unsafe X509Certificate2 ITlsConnectionFeature.ClientCertificate
 
         IEnumerator IEnumerable.GetEnumerator() => FastEnumerable().GetEnumerator();
 
-        bool IHttpBodyControlFeature.AllowSynchronousIO { get; set; } = true;
+        bool IHttpBodyControlFeature.AllowSynchronousIO { get; set; }
 
         void IHttpBufferingFeature.DisableRequestBuffering()
         {

src/Servers/IIS/IIS/src/IISServerOptions.cs

@@ -11,9 +11,9 @@ public class IISServerOptions
         /// Gets or sets a value that controls whether synchronous IO is allowed for the <see cref="HttpContext.Request"/> and <see cref="HttpContext.Response"/>
         /// </summary>
         /// <remarks>
-        /// Defaults to true.
+        /// Defaults to false.
         /// </remarks>
-        public bool AllowSynchronousIO { get; set; } = true;
+        public bool AllowSynchronousIO { get; set; } = false;
 
         /// <summary>
         /// If true the server should set HttpContext.User. If false the server will only provide an

src/Servers/IIS/IIS/test/IIS.Tests/ConnectionIdFeatureTests.cs

@@ -1,7 +1,6 @@
 // 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.Threading.Tasks;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Testing.xunit;
@@ -11,44 +10,22 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
 {
     [SkipIfHostableWebCoreNotAvailable]
     [OSSkipCondition(OperatingSystems.Windows, WindowsVersions.Win7, "https://github.com/aspnet/IISIntegration/issues/866")]
-    public class HttpBodyControlFeatureTests : StrictTestServerTests
+    public class ConnectionIdFeatureTests : StrictTestServerTests
     {
         [ConditionalFact]
-        public async Task ThrowsOnSyncReadOrWrite()
+        public async Task ProvidesConnectionId()
         {
-            Exception writeException = null;
-            Exception readException = null;
-            using (var testServer = await TestServer.Create(
-                ctx => {
-                    var bodyControl = ctx.Features.Get<IHttpBodyControlFeature>();
-                    bodyControl.AllowSynchronousIO = false;
-
-                    try
-                    {
-                        ctx.Response.Body.Write(new byte[10]);
-                    }
-                    catch (Exception ex)
-                    {
-                        writeException = ex;
-                    }
-
-                    try
-                    {
-                        ctx.Request.Body.Read(new byte[10]);
-                    }
-                    catch (Exception ex)
-                    {
-                        readException = ex;
-                    }
-
-                    return Task.CompletedTask;
-                }, LoggerFactory))
+            string connectionId = null;
+            using (var testServer = await TestServer.Create(ctx => {
+                var connectionIdFeature = ctx.Features.Get<IHttpConnectionFeature>();
+                connectionId = connectionIdFeature.ConnectionId;
+                return Task.CompletedTask;
+            }, LoggerFactory))
             {
                 await testServer.HttpClient.GetStringAsync("/");
             }
 
-            Assert.IsType<InvalidOperationException>(readException);
-            Assert.IsType<InvalidOperationException>(writeException);
+            Assert.NotNull(connectionId);
         }
     }
 }

src/Servers/IIS/IIS/test/IIS.Tests/HttpBodyControlFeatureTests.cs

@@ -1,6 +1,7 @@
 // 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.Threading.Tasks;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Testing.xunit;
@@ -10,22 +11,44 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
 {
     [SkipIfHostableWebCoreNotAvailable]
     [OSSkipCondition(OperatingSystems.Windows, WindowsVersions.Win7, "https://github.com/aspnet/IISIntegration/issues/866")]
-    public class ConnectionIdFeatureTests : StrictTestServerTests
+    public class HttpBodyControlFeatureTests : StrictTestServerTests
     {
         [ConditionalFact]
-        public async Task ProvidesConnectionId()
+        public async Task ThrowsOnSyncReadOrWrite()
         {
-            string connectionId = null;
-            using (var testServer = await TestServer.Create(ctx => {
-                    var connectionIdFeature = ctx.Features.Get<IHttpConnectionFeature>();
-                    connectionId = connectionIdFeature.ConnectionId;
+            Exception writeException = null;
+            Exception readException = null;
+            using (var testServer = await TestServer.Create(
+                ctx => {
+                    var bodyControl = ctx.Features.Get<IHttpBodyControlFeature>();
+                    Assert.False(bodyControl.AllowSynchronousIO);
+
+                    try
+                    {
+                        ctx.Response.Body.Write(new byte[10]);
+                    }
+                    catch (Exception ex)
+                    {
+                        writeException = ex;
+                    }
+
+                    try
+                    {
+                        ctx.Request.Body.Read(new byte[10]);
+                    }
+                    catch (Exception ex)
+                    {
+                        readException = ex;
+                    }
+
                     return Task.CompletedTask;
                 }, LoggerFactory))
             {
                 await testServer.HttpClient.GetStringAsync("/");
             }
 
-            Assert.NotNull(connectionId);
+            Assert.IsType<InvalidOperationException>(readException);
+            Assert.IsType<InvalidOperationException>(writeException);
         }
     }
 }

src/Servers/Kestrel/Core/src/KestrelServerOptions.cs

@@ -50,9 +50,9 @@ public class KestrelServerOptions
         /// Gets or sets a value that controls whether synchronous IO is allowed for the <see cref="HttpContext.Request"/> and <see cref="HttpContext.Response"/>
         /// </summary>
         /// <remarks>
-        /// Defaults to true.
+        /// Defaults to false.
         /// </remarks>
-        public bool AllowSynchronousIO { get; set; } = true;
+        public bool AllowSynchronousIO { get; set; } = false;
 
         /// <summary>
         /// Enables the Listen options callback to resolve and use services registered by the application during startup.

src/Servers/Kestrel/Core/test/KestrelServerOptionsTests.cs

@@ -23,11 +23,11 @@ public void NoDelayDefaultsToTrue()
         }
 
         [Fact]
-        public void AllowSynchronousIODefaultsToTrue()
+        public void AllowSynchronousIODefaultsToFalse()
         {
             var options = new KestrelServerOptions();
 
-            Assert.True(options.AllowSynchronousIO);
+            Assert.False(options.AllowSynchronousIO);
         }
 
         [Fact]
@@ -65,4 +65,4 @@ public void ConfigureEndpointDefaultsAppliesToNewEndpoints()
             Assert.False(options.ListenOptions[3].NoDelay);
         }
     }
-}
+}