React to pipes in corefx (#2337)

Directory.Build.props

@@ -17,5 +17,7 @@
     <PublicSign Condition="'$(OS)' != 'Windows_NT'">true</PublicSign>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <LangVersion>latest</LangVersion>
+    <!-- https://github.com/aspnet/KestrelHttpServer/issues/2350 -->
+    <EnableApiCheck>false</EnableApiCheck>
   </PropertyGroup>
 </Project>

benchmarks/Kestrel.Performance/Http1ConnectionParsingOverheadBenchmark.cs

@@ -9,6 +9,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Performance.Mocks;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 {
@@ -16,13 +17,13 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
     {
         private const int InnerLoopCount = 512;
 
-        public ReadOnlyBuffer<byte> _buffer;
+        public ReadOnlySequence<byte> _buffer;
         public Http1Connection _http1Connection;
 
         [IterationSetup]
         public void Setup()
         {
-            var memoryPool = new MemoryPool();
+            var memoryPool = KestrelMemoryPool.Create();
             var pair = DuplexPipe.CreateConnectionPair(memoryPool);
 
             var serviceContext = new ServiceContext

benchmarks/Kestrel.Performance/Http1WritingBenchmark.cs

@@ -12,6 +12,7 @@ using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Performance
@@ -24,15 +25,17 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         private static readonly Task _psuedoAsyncTask = Task.FromResult(27);
         private static readonly Func<object, Task> _psuedoAsyncTaskFunc = (obj) => _psuedoAsyncTask;
 
-        private readonly TestHttp1Connection _http1Connection;
+        private TestHttp1Connection _http1Connection;
         private DuplexPipe.DuplexPipePair _pair;
+        private MemoryPool<byte> _memoryPool;
 
-        private readonly byte[] _writeData;
+        private readonly byte[] _writeData = Encoding.ASCII.GetBytes("Hello, World!");
 
-        public Http1WritingBenchmark()
+        [GlobalSetup]
+        public void GlobalSetup()
         {
+            _memoryPool = KestrelMemoryPool.Create();
             _http1Connection = MakeHttp1Connection();
-            _writeData = Encoding.ASCII.GetBytes("Hello, World!");
         }
 
         [Params(true, false)]
@@ -93,33 +96,30 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 
         private TestHttp1Connection MakeHttp1Connection()
         {
-            using (var memoryPool = new MemoryPool())
+            var pair = DuplexPipe.CreateConnectionPair(_memoryPool);
+            _pair = pair;
+
+            var serviceContext = new ServiceContext
             {
-                var pair = DuplexPipe.CreateConnectionPair(memoryPool);
+                DateHeaderValueManager = new DateHeaderValueManager(),
-                _pair = pair;
+                ServerOptions = new KestrelServerOptions(),
+                Log = new MockTrace(),
+                HttpParser = new HttpParser<Http1ParsingHandler>()
+            };
 
-                var serviceContext = new ServiceContext
+            var http1Connection = new TestHttp1Connection(new Http1ConnectionContext
-                {
+            {
-                    DateHeaderValueManager = new DateHeaderValueManager(),
+                ServiceContext = serviceContext,
-                    ServerOptions = new KestrelServerOptions(),
+                ConnectionFeatures = new FeatureCollection(),
-                    Log = new MockTrace(),
+                MemoryPool = _memoryPool,
-                    HttpParser = new HttpParser<Http1ParsingHandler>()
+                Application = pair.Application,
-                };
+                Transport = pair.Transport
+            });
 
-                var http1Connection = new TestHttp1Connection(new Http1ConnectionContext
+            http1Connection.Reset();
-                {
+            http1Connection.InitializeStreams(MessageBody.ZeroContentLengthKeepAlive);
-                    ServiceContext = serviceContext,
-                    ConnectionFeatures = new FeatureCollection(),
-                    MemoryPool = memoryPool,
-                    Application = pair.Application,
-                    Transport = pair.Transport
-                });
 
-                http1Connection.Reset();
+            return http1Connection;
-                http1Connection.InitializeStreams(MessageBody.ZeroContentLengthKeepAlive);
-
-                return http1Connection;
-            }
         }
 
         [IterationCleanup]
@@ -138,5 +138,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
             Sync,
             Async
         }
+
+        [GlobalCleanup]
+        public void Dispose()
+        {
+            _memoryPool?.Dispose();
+        }
     }
 }

benchmarks/Kestrel.Performance/HttpParserBenchmark.cs

@@ -12,7 +12,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
     {
         private readonly HttpParser<Adapter> _parser = new HttpParser<Adapter>();
 
-        private ReadOnlyBuffer<byte> _buffer;
+        private ReadOnlySequence<byte> _buffer;
 
         [Benchmark(Baseline = true, OperationsPerInvoke = RequestParsingData.InnerLoopCount)]
         public void PlaintextTechEmpower()
@@ -46,7 +46,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 
         private void InsertData(byte[] data)
         {
-            _buffer = new ReadOnlyBuffer<byte>(data);
+            _buffer = new ReadOnlySequence<byte>(data);
         }
 
         private void ParseData()

benchmarks/Kestrel.Performance/HttpProtocolFeatureCollection.cs

@@ -12,6 +12,7 @@ using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 {
@@ -78,7 +79,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 
         public HttpProtocolFeatureCollection()
         {
-            var memoryPool = new MemoryPool();
+            var memoryPool = KestrelMemoryPool.Create();
             var pair = DuplexPipe.CreateConnectionPair(memoryPool);
 
             var serviceContext = new ServiceContext

benchmarks/Kestrel.Performance/Mocks/NullParser.cs

@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 
         public static readonly NullParser<Http1ParsingHandler> Instance = new NullParser<Http1ParsingHandler>();
 
-        public bool ParseHeaders(TRequestHandler handler, ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined, out int consumedBytes)
+        public bool ParseHeaders(TRequestHandler handler, ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined, out int consumedBytes)
         {
             handler.OnHeader(new Span<byte>(_hostHeaderName), new Span<byte>(_hostHeaderValue));
             handler.OnHeader(new Span<byte>(_acceptHeaderName), new Span<byte>(_acceptHeaderValue));
@@ -35,7 +35,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
             return true;
         }
 
-        public bool ParseRequestLine(TRequestHandler handler, ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
+        public bool ParseRequestLine(TRequestHandler handler, ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
         {
             handler.OnStartLine(HttpMethod.Get,
                 HttpVersion.Http11,

benchmarks/Kestrel.Performance/PipeThroughputBenchmark.cs

@@ -1,10 +1,12 @@
 // 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.Buffers;
 using System.IO.Pipelines;
 using System.Threading.Tasks;
 using BenchmarkDotNet.Attributes;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 {
@@ -14,12 +16,12 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         private const int InnerLoopCount = 512;
 
         private Pipe _pipe;
-        private MemoryPool _memoryPool;
+        private MemoryPool<byte> _memoryPool;
 
         [IterationSetup]
         public void Setup()
         {
-            _memoryPool = new MemoryPool();
+            _memoryPool = KestrelMemoryPool.Create();
             _pipe = new Pipe(new PipeOptions(_memoryPool));
         }
 
@@ -62,5 +64,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
                 _pipe.Reader.AdvanceTo(result.Buffer.End, result.Buffer.End);
             }
         }
+
+        [IterationCleanup]
+        public void Cleanup()
+        {
+            _memoryPool.Dispose();
+        }
     }
 }

benchmarks/Kestrel.Performance/RequestParsingBenchmark.cs

@@ -9,11 +9,14 @@ using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Performance.Mocks;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 {
     public class RequestParsingBenchmark
     {
+        private MemoryPool<byte> _memoryPool;
+
         public Pipe Pipe { get; set; }
 
         public Http1Connection Http1Connection { get; set; }
@@ -21,8 +24,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         [IterationSetup]
         public void Setup()
         {
-            var memoryPool = new MemoryPool();
+            _memoryPool = KestrelMemoryPool.Create();
-            var pair = DuplexPipe.CreateConnectionPair(memoryPool);
+            var pair = DuplexPipe.CreateConnectionPair(_memoryPool);
 
             var serviceContext = new ServiceContext
             {
@@ -36,7 +39,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
             {
                 ServiceContext = serviceContext,
                 ConnectionFeatures = new FeatureCollection(),
-                MemoryPool = memoryPool,
+                MemoryPool = _memoryPool,
                 Application = pair.Application,
                 Transport = pair.Transport,
                 TimeoutControl = new MockTimeoutControl()
@@ -45,7 +48,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
             http1Connection.Reset();
 
             Http1Connection = http1Connection;
-            Pipe = new Pipe(new PipeOptions(memoryPool));
+            Pipe = new Pipe(new PipeOptions(_memoryPool));
         }
 
         [Benchmark(Baseline = true, OperationsPerInvoke = RequestParsingData.InnerLoopCount)]
@@ -201,5 +204,12 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
             }
             while (true);
         }
+
+
+        [IterationCleanup]
+        public void Cleanup()
+        {
+            _memoryPool.Dispose();
+        }
     }
 }

benchmarks/Kestrel.Performance/ResponseHeaderCollectionBenchmark.cs

@@ -12,6 +12,7 @@ using Microsoft.AspNetCore.Http.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 {
@@ -170,7 +171,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         [IterationSetup]
         public void Setup()
         {
-            var memoryPool = new MemoryPool();
+            var memoryPool = KestrelMemoryPool.Create();
             var pair = DuplexPipe.CreateConnectionPair(memoryPool);
 
             var serviceContext = new ServiceContext

benchmarks/Kestrel.Performance/ResponseHeadersWritingBenchmark.cs

@@ -13,6 +13,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Performance.Mocks;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Performance
@@ -23,6 +24,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
 
         private TestHttp1Connection _http1Connection;
 
+        private MemoryPool<byte> _memoryPool;
+
         [Params(
             BenchmarkTypes.TechEmpowerPlaintext,
             BenchmarkTypes.PlaintextChunked,
@@ -110,8 +113,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         [IterationSetup]
         public void Setup()
         {
-            var memoryPool = new MemoryPool();
+            _memoryPool = KestrelMemoryPool.Create();
-            var pair = DuplexPipe.CreateConnectionPair(memoryPool);
+            var pair = DuplexPipe.CreateConnectionPair(_memoryPool);
 
             var serviceContext = new ServiceContext
             {
@@ -125,7 +128,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
             {
                 ServiceContext = serviceContext,
                 ConnectionFeatures = new FeatureCollection(),
-                MemoryPool = memoryPool,
+                MemoryPool = _memoryPool,
                 TimeoutControl = new MockTimeoutControl(),
                 Application = pair.Application,
                 Transport = pair.Transport
@@ -136,6 +139,12 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
             _http1Connection = http1Connection;
         }
 
+        [IterationCleanup]
+        public void Cleanup()
+        {
+            _memoryPool.Dispose();
+        }
+
         public enum BenchmarkTypes
         {
             TechEmpowerPlaintext,

build/dependencies.props

@@ -5,40 +5,39 @@
   <!-- This files is typically managed by automation. Execute 'run.ps1 upgrade deps' to update these variables to the last-known-good versions. -->
   <PropertyGroup Label="Package Versions">
     <BenchmarkDotNetPackageVersion>0.10.11</BenchmarkDotNetPackageVersion>
-    <InternalAspNetCoreSdkPackageVersion>2.1.0-preview2-15721</InternalAspNetCoreSdkPackageVersion>
+    <InternalAspNetCoreSdkPackageVersion>2.1.0-preview2-15707</InternalAspNetCoreSdkPackageVersion>
     <LibuvPackageVersion>1.10.0</LibuvPackageVersion>
-    <MicrosoftAspNetCoreBenchmarkRunnerSourcesPackageVersion>2.1.0-preview2-30187</MicrosoftAspNetCoreBenchmarkRunnerSourcesPackageVersion>
+    <MicrosoftAspNetCoreBenchmarkRunnerSourcesPackageVersion>2.1.0-preview2-30131</MicrosoftAspNetCoreBenchmarkRunnerSourcesPackageVersion>
-    <MicrosoftAspNetCoreCertificatesGenerationSourcesPackageVersion>2.1.0-preview2-30187</MicrosoftAspNetCoreCertificatesGenerationSourcesPackageVersion>
+    <MicrosoftAspNetCoreCertificatesGenerationSourcesPackageVersion>2.1.0-preview2-30131</MicrosoftAspNetCoreCertificatesGenerationSourcesPackageVersion>
-    <MicrosoftAspNetCoreHostingAbstractionsPackageVersion>2.1.0-preview2-30187</MicrosoftAspNetCoreHostingAbstractionsPackageVersion>
+    <MicrosoftAspNetCoreHostingAbstractionsPackageVersion>2.1.0-preview2-30131</MicrosoftAspNetCoreHostingAbstractionsPackageVersion>
-    <MicrosoftAspNetCoreHostingPackageVersion>2.1.0-preview2-30187</MicrosoftAspNetCoreHostingPackageVersion>
+    <MicrosoftAspNetCoreHostingPackageVersion>2.1.0-preview2-30131</MicrosoftAspNetCoreHostingPackageVersion>
-    <MicrosoftAspNetCoreHttpAbstractionsPackageVersion>2.1.0-preview2-30187</MicrosoftAspNetCoreHttpAbstractionsPackageVersion>
+    <MicrosoftAspNetCoreHttpAbstractionsPackageVersion>2.1.0-preview2-30131</MicrosoftAspNetCoreHttpAbstractionsPackageVersion>
-    <MicrosoftAspNetCoreHttpFeaturesPackageVersion>2.1.0-preview2-30187</MicrosoftAspNetCoreHttpFeaturesPackageVersion>
+    <MicrosoftAspNetCoreHttpFeaturesPackageVersion>2.1.0-preview2-30131</MicrosoftAspNetCoreHttpFeaturesPackageVersion>
-    <MicrosoftAspNetCoreHttpPackageVersion>2.1.0-preview2-30187</MicrosoftAspNetCoreHttpPackageVersion>
+    <MicrosoftAspNetCoreHttpPackageVersion>2.1.0-preview2-30131</MicrosoftAspNetCoreHttpPackageVersion>
-    <MicrosoftAspNetCoreTestingPackageVersion>2.1.0-preview2-30187</MicrosoftAspNetCoreTestingPackageVersion>
+    <MicrosoftAspNetCoreTestingPackageVersion>2.1.0-preview2-30131</MicrosoftAspNetCoreTestingPackageVersion>
-    <MicrosoftAspNetCoreWebUtilitiesPackageVersion>2.1.0-preview2-30187</MicrosoftAspNetCoreWebUtilitiesPackageVersion>
+    <MicrosoftAspNetCoreWebUtilitiesPackageVersion>2.1.0-preview2-30131</MicrosoftAspNetCoreWebUtilitiesPackageVersion>
-    <MicrosoftExtensionsConfigurationBinderPackageVersion>2.1.0-preview2-30187</MicrosoftExtensionsConfigurationBinderPackageVersion>
+    <MicrosoftExtensionsBuffersSourcesPackageVersion>2.1.0-preview2-t000</MicrosoftExtensionsBuffersSourcesPackageVersion>
-    <MicrosoftExtensionsConfigurationJsonPackageVersion>2.1.0-preview2-30187</MicrosoftExtensionsConfigurationJsonPackageVersion>
+    <MicrosoftExtensionsConfigurationBinderPackageVersion>2.1.0-preview2-30131</MicrosoftExtensionsConfigurationBinderPackageVersion>
-    <MicrosoftExtensionsDependencyInjectionPackageVersion>2.1.0-preview2-30187</MicrosoftExtensionsDependencyInjectionPackageVersion>
+    <MicrosoftExtensionsConfigurationJsonPackageVersion>2.1.0-preview2-30131</MicrosoftExtensionsConfigurationJsonPackageVersion>
-    <MicrosoftExtensionsLoggingAbstractionsPackageVersion>2.1.0-preview2-30187</MicrosoftExtensionsLoggingAbstractionsPackageVersion>
+    <MicrosoftExtensionsDependencyInjectionPackageVersion>2.1.0-preview2-30131</MicrosoftExtensionsDependencyInjectionPackageVersion>
-    <MicrosoftExtensionsLoggingConsolePackageVersion>2.1.0-preview2-30187</MicrosoftExtensionsLoggingConsolePackageVersion>
+    <MicrosoftExtensionsLoggingAbstractionsPackageVersion>2.1.0-preview2-30131</MicrosoftExtensionsLoggingAbstractionsPackageVersion>
-    <MicrosoftExtensionsLoggingPackageVersion>2.1.0-preview2-30187</MicrosoftExtensionsLoggingPackageVersion>
+    <MicrosoftExtensionsLoggingConsolePackageVersion>2.1.0-preview2-30131</MicrosoftExtensionsLoggingConsolePackageVersion>
-    <MicrosoftExtensionsLoggingTestingPackageVersion>2.1.0-preview2-30187</MicrosoftExtensionsLoggingTestingPackageVersion>
+    <MicrosoftExtensionsLoggingPackageVersion>2.1.0-preview2-30131</MicrosoftExtensionsLoggingPackageVersion>
-    <MicrosoftExtensionsOptionsPackageVersion>2.1.0-preview2-30187</MicrosoftExtensionsOptionsPackageVersion>
+    <MicrosoftExtensionsLoggingTestingPackageVersion>2.1.0-preview2-30131</MicrosoftExtensionsLoggingTestingPackageVersion>
+    <MicrosoftExtensionsOptionsPackageVersion>2.1.0-preview2-30131</MicrosoftExtensionsOptionsPackageVersion>
     <MicrosoftNETCoreApp20PackageVersion>2.0.0</MicrosoftNETCoreApp20PackageVersion>
-    <MicrosoftNETCoreApp21PackageVersion>2.1.0-preview2-26130-04</MicrosoftNETCoreApp21PackageVersion>
+    <MicrosoftNETCoreApp21PackageVersion>2.1.0-preview2-26225-03</MicrosoftNETCoreApp21PackageVersion>
-    <MicrosoftNetHttpHeadersPackageVersion>2.1.0-preview2-30187</MicrosoftNetHttpHeadersPackageVersion>
+    <MicrosoftNetHttpHeadersPackageVersion>2.1.0-preview2-30131</MicrosoftNetHttpHeadersPackageVersion>
-    <MicrosoftNETTestSdkPackageVersion>15.6.0</MicrosoftNETTestSdkPackageVersion>
+    <MicrosoftNETTestSdkPackageVersion>15.3.0</MicrosoftNETTestSdkPackageVersion>
     <MoqPackageVersion>4.7.49</MoqPackageVersion>
     <NewtonsoftJsonPackageVersion>10.0.1</NewtonsoftJsonPackageVersion>
-    <SystemBuffersPackageVersion>4.5.0-preview2-26130-01</SystemBuffersPackageVersion>
+    <SystemBuffersPackageVersion>4.5.0-preview2-26224-02</SystemBuffersPackageVersion>
-    <SystemBuffersPrimitivesPackageVersion>0.1.0-preview2-180130-1</SystemBuffersPrimitivesPackageVersion>
+    <SystemIOPipelinesPackageVersion>4.5.0-preview2-26224-02</SystemIOPipelinesPackageVersion>
-    <SystemIOPipelinesPackageVersion>0.1.0-preview2-180130-1</SystemIOPipelinesPackageVersion>
+    <SystemMemoryPackageVersion>4.5.0-preview2-26224-02</SystemMemoryPackageVersion>
-    <SystemMemoryPackageVersion>4.5.0-preview2-26130-01</SystemMemoryPackageVersion>
+    <SystemNumericsVectorsPackageVersion>4.5.0-preview2-26224-02</SystemNumericsVectorsPackageVersion>
-    <SystemNumericsVectorsPackageVersion>4.5.0-preview2-26130-01</SystemNumericsVectorsPackageVersion>
+    <SystemRuntimeCompilerServicesUnsafePackageVersion>4.5.0-preview2-26224-02</SystemRuntimeCompilerServicesUnsafePackageVersion>
-    <SystemRuntimeCompilerServicesUnsafePackageVersion>4.5.0-preview2-26130-01</SystemRuntimeCompilerServicesUnsafePackageVersion>
+    <SystemSecurityCryptographyCngPackageVersion>4.5.0-preview2-26224-02</SystemSecurityCryptographyCngPackageVersion>
-    <SystemSecurityCryptographyCngPackageVersion>4.5.0-preview2-26130-01</SystemSecurityCryptographyCngPackageVersion>
+    <SystemThreadingTasksExtensionsPackageVersion>4.5.0-preview2-26224-02</SystemThreadingTasksExtensionsPackageVersion>
-    <SystemTextEncodingsWebUtf8PackageVersion>0.1.0-preview2-180130-1</SystemTextEncodingsWebUtf8PackageVersion>
-    <SystemThreadingTasksExtensionsPackageVersion>4.5.0-preview2-26130-01</SystemThreadingTasksExtensionsPackageVersion>
     <XunitAnalyzersPackageVersion>0.8.0</XunitAnalyzersPackageVersion>
     <XunitPackageVersion>2.3.1</XunitPackageVersion>
     <XunitRunnerVisualStudioPackageVersion>2.4.0-beta.1.build3945</XunitRunnerVisualStudioPackageVersion>

src/Kestrel.Core/Adapter/Internal/AdaptedPipeline.cs

@@ -62,7 +62,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Adapter.Internal
 
                     try
                     {
-                        if (result.IsCancelled)
+                        if (result.IsCanceled)
                         {
                             // Forward the cancellation to the transport pipe
                             _application.Input.CancelPendingRead();
@@ -132,26 +132,18 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Adapter.Internal
                 {
 
                     var outputBuffer = Input.Writer.GetMemory(MinAllocBufferSize);
-
-                    try
-                    {
 #if NETCOREAPP2_1
-                        var bytesRead = await stream.ReadAsync(outputBuffer);
+                    var bytesRead = await stream.ReadAsync(outputBuffer);
 #else
-                        var array = outputBuffer.GetArray();
+                    var array = outputBuffer.GetArray();
-                        var bytesRead = await stream.ReadAsync(array.Array, array.Offset, array.Count);
+                    var bytesRead = await stream.ReadAsync(array.Array, array.Offset, array.Count);
 #endif
-                        Input.Writer.Advance(bytesRead);
+                    Input.Writer.Advance(bytesRead);
 
-                        if (bytesRead == 0)
+                    if (bytesRead == 0)
-                        {
-                            // FIN
-                            break;
-                        }
-                    }
-                    finally
                     {
-                        Input.Writer.Commit();
+                        // FIN
+                        break;
                     }
 
                     var result = await Input.Writer.FlushAsync();
@@ -160,7 +152,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Adapter.Internal
                     {
                         break;
                     }
-
                 }
             }
             catch (Exception ex)

src/Kestrel.Core/Internal/ConnectionHandler.cs

@@ -83,7 +83,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
         }
 
         // Internal for testing
-        internal static PipeOptions GetInputPipeOptions(ServiceContext serviceContext, MemoryPool memoryPool, PipeScheduler writerScheduler) => new PipeOptions
+        internal static PipeOptions GetInputPipeOptions(ServiceContext serviceContext, MemoryPool<byte> memoryPool, PipeScheduler writerScheduler) => new PipeOptions
         (
             pool: memoryPool,
             readerScheduler: serviceContext.ThreadPool,
@@ -92,7 +92,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
             resumeWriterThreshold: serviceContext.ServerOptions.Limits.MaxRequestBufferSize ?? 0
         );
 
-        internal static PipeOptions GetOutputPipeOptions(ServiceContext serviceContext, MemoryPool memoryPool, PipeScheduler readerScheduler) => new PipeOptions
+        internal static PipeOptions GetOutputPipeOptions(ServiceContext serviceContext, MemoryPool<byte> memoryPool, PipeScheduler readerScheduler) => new PipeOptions
         (
             pool: memoryPool,
             readerScheduler: readerScheduler,

src/Kestrel.Core/Internal/Http/ChunkWriter.cs

@@ -8,7 +8,7 @@ using System.Text;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 {
-    public static class ChunkWriter
+    internal static class ChunkWriter
     {
         private static readonly ArraySegment<byte> _endChunkBytes = CreateAsciiByteArraySegment("\r\n");
         private static readonly byte[] _hex = Encoding.ASCII.GetBytes("0123456789abcdef");
@@ -48,14 +48,14 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return new ArraySegment<byte>(bytes, offset, 10 - offset);
         }
 
-        public static int WriteBeginChunkBytes(ref OutputWriter<PipeWriter> start, int dataCount)
+        internal static int WriteBeginChunkBytes(ref BufferWriter<PipeWriter> start, int dataCount)
         {
             var chunkSegment = BeginChunkBytes(dataCount);
             start.Write(new ReadOnlySpan<byte>(chunkSegment.Array, chunkSegment.Offset, chunkSegment.Count));
             return chunkSegment.Count;
         }
 
-        public static void WriteEndChunkBytes(ref OutputWriter<PipeWriter> start)
+        internal static void WriteEndChunkBytes(ref BufferWriter<PipeWriter> start)
         {
             start.Write(new ReadOnlySpan<byte>(_endChunkBytes.Array, _endChunkBytes.Offset, _endChunkBytes.Count));
         }

src/Kestrel.Core/Internal/Http/Http1Connection.cs

@@ -8,9 +8,10 @@ using System.Diagnostics;
 using System.IO.Pipelines;
 using System.Runtime.InteropServices;
 using System.Text;
-using System.Text.Encodings.Web.Utf8;
+using System.Text.Encodings.Web;
 using System.Threading;
 using Microsoft.AspNetCore.Http.Features;
+using Microsoft.AspNetCore.Protocols.Abstractions;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
@@ -69,7 +70,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             Input.CancelPendingRead();
         }
 
-        public void ParseRequest(ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
+        public void ParseRequest(ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
         {
             consumed = buffer.Start;
             examined = buffer.End;
@@ -107,7 +108,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             }
         }
 
-        public bool TakeStartLine(ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
+        public bool TakeStartLine(ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
         {
             var overLength = false;
             if (buffer.Length >= ServerOptions.Limits.MaxRequestLineSize)
@@ -125,7 +126,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return result;
         }
 
-        public bool TakeMessageHeaders(ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
+        public bool TakeMessageHeaders(ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
         {
             // Make sure the buffer is limited
             bool overLength = false;
@@ -217,9 +218,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 {
                     // URI was encoded, unescape and then parse as UTF-8
                     // Disabling warning temporary
-#pragma warning disable 618
+                    var pathLength = UrlDecoder.Decode(path, path);
-                    var pathLength = UrlEncoder.Decode(path, path);
-#pragma warning restore 618
 
                     // Removing dot segments must be done after unescaping. From RFC 3986:
                     //
@@ -430,7 +429,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             TimeoutControl.SetTimeout(_keepAliveTicks, TimeoutAction.StopProcessingNextRequest);
         }
 
-        protected override bool BeginRead(out ValueAwaiter<ReadResult> awaitable)
+        protected override bool BeginRead(out PipeAwaiter<ReadResult> awaitable)
         {
             awaitable = Input.ReadAsync();
             return true;

src/Kestrel.Core/Internal/Http/Http1ConnectionContext.cs

@@ -14,7 +14,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         public string ConnectionId { get; set; }
         public ServiceContext ServiceContext { get; set; }
         public IFeatureCollection ConnectionFeatures { get; set; }
-        public MemoryPool MemoryPool { get; set; }
+        public MemoryPool<byte> MemoryPool { get; set; }
         public IPEndPoint RemoteEndPoint { get; set; }
         public IPEndPoint LocalEndPoint { get; set; }
         public ITimeoutControl TimeoutControl { get; set; }

src/Kestrel.Core/Internal/Http/Http1MessageBody.cs

@@ -8,6 +8,7 @@ using System.IO;
 using System.IO.Pipelines;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Protocols.Abstractions;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
@@ -63,15 +64,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                         if (!readableBuffer.IsEmpty)
                         {
                             bool done;
-
+                            done = Read(readableBuffer, _context.RequestBodyPipe.Writer, out consumed, out examined);
-                            try
-                            {
-                                done = Read(readableBuffer, _context.RequestBodyPipe.Writer, out consumed, out examined);
-                            }
-                            finally
-                            {
-                                _context.RequestBodyPipe.Writer.Commit();
-                            }
 
                             var writeAwaitable = _context.RequestBodyPipe.Writer.FlushAsync();
                             var backpressure = false;
@@ -150,7 +143,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             }
         }
 
-        protected void Copy(ReadOnlyBuffer<byte> readableBuffer, PipeWriter writableBuffer)
+        protected void Copy(ReadOnlySequence<byte> readableBuffer, PipeWriter writableBuffer)
         {
             _context.TimeoutControl.BytesRead(readableBuffer.Length);
 
@@ -172,7 +165,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             _pumpTask = PumpAsync();
         }
 
-        protected virtual bool Read(ReadOnlyBuffer<byte> readableBuffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
+        protected virtual bool Read(ReadOnlySequence<byte> readableBuffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
         {
             throw new NotImplementedException();
         }
@@ -295,7 +288,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 
             public override bool IsEmpty => true;
 
-            protected override bool Read(ReadOnlyBuffer<byte> readableBuffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
+            protected override bool Read(ReadOnlySequence<byte> readableBuffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
             {
                 Copy(readableBuffer, writableBuffer);
                 consumed = readableBuffer.End;
@@ -317,7 +310,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 _inputLength = _contentLength;
             }
 
-            protected override bool Read(ReadOnlyBuffer<byte> readableBuffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
+            protected override bool Read(ReadOnlySequence<byte> readableBuffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
             {
                 if (_inputLength == 0)
                 {
@@ -365,7 +358,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 RequestKeepAlive = keepAlive;
             }
 
-            protected override bool Read(ReadOnlyBuffer<byte> readableBuffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
+            protected override bool Read(ReadOnlySequence<byte> readableBuffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
             {
                 consumed = default(SequencePosition);
                 examined = default(SequencePosition);
@@ -456,11 +449,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 }
             }
 
-            private void ParseChunkedPrefix(ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
+            private void ParseChunkedPrefix(ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
             {
                 consumed = buffer.Start;
                 examined = buffer.Start;
-                var reader = BufferReader.Create(buffer);
+                var reader = new BufferReader(buffer);
                 var ch1 = reader.Read();
                 var ch2 = reader.Read();
 
@@ -512,7 +505,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 BadHttpRequestException.Throw(RequestRejectionReason.BadChunkSizeData);
             }
 
-            private void ParseExtension(ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
+            private void ParseExtension(ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
             {
                 // Chunk-extensions not currently parsed
                 // Just drain the data
@@ -565,7 +558,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 } while (_mode == Mode.Extension);
             }
 
-            private void ReadChunkedData(ReadOnlyBuffer<byte> buffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
+            private void ReadChunkedData(ReadOnlySequence<byte> buffer, PipeWriter writableBuffer, out SequencePosition consumed, out SequencePosition examined)
             {
                 var actual = Math.Min(buffer.Length, _inputLength);
                 consumed = buffer.GetPosition(buffer.Start, actual);
@@ -582,7 +575,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 }
             }
 
-            private void ParseChunkedSuffix(ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
+            private void ParseChunkedSuffix(ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
             {
                 consumed = buffer.Start;
                 examined = buffer.Start;
@@ -608,7 +601,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 }
             }
 
-            private void ParseChunkedTrailer(ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
+            private void ParseChunkedTrailer(ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
             {
                 consumed = buffer.Start;
                 examined = buffer.Start;

src/Kestrel.Core/Internal/Http/Http1OutputProducer.cs

@@ -84,7 +84,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 
                 var buffer = _pipeWriter;
                 callback(buffer, state);
-                buffer.Commit();
             }
         }
 
@@ -99,7 +98,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 
                 var buffer = _pipeWriter;
                 callback(buffer, state);
-                buffer.Commit();
             }
 
             return FlushAsync();
@@ -115,14 +113,14 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 }
 
                 var buffer = _pipeWriter;
-                var writer = OutputWriter.Create(buffer);
+                var writer = new BufferWriter<PipeWriter>(buffer);
 
                 writer.Write(_bytesHttpVersion11);
                 var statusBytes = ReasonPhrases.ToStatusBytes(statusCode, reasonPhrase);
                 writer.Write(statusBytes);
                 responseHeaders.CopyTo(ref writer);
                 writer.Write(_bytesEndHeaders);
-                buffer.Commit();
+                writer.Commit();
             }
         }
 
@@ -177,14 +175,13 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 }
 
                 writableBuffer = _pipeWriter;
-                var writer = OutputWriter.Create(writableBuffer);
+                var writer = new BufferWriter<PipeWriter>(writableBuffer);
                 if (buffer.Length > 0)
                 {
                     writer.Write(buffer);
                     bytesWritten += buffer.Length;
                 }
-
+                writer.Commit();
-                writableBuffer.Commit();
             }
 
             return FlushAsync(writableBuffer, bytesWritten, cancellationToken);
@@ -203,7 +200,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return FlushAsyncAwaited(awaitable, bytesWritten, cancellationToken);
         }
 
-        private async Task FlushAsyncAwaited(ValueAwaiter<FlushResult> awaitable, long count, CancellationToken cancellationToken)
+        private async Task FlushAsyncAwaited(PipeAwaiter<FlushResult> awaitable, long count, CancellationToken cancellationToken)
         {
             // https://github.com/dotnet/corefxlab/issues/1334
             // Since the flush awaitable doesn't currently support multiple awaiters

src/Kestrel.Core/Internal/Http/HttpHeaders.Generated.cs

@@ -7754,7 +7754,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return true;
         }
         
-        protected void CopyToFast(ref OutputWriter<PipeWriter> output)
+        internal void CopyToFast(ref BufferWriter<PipeWriter> output)
         {
             var tempBits = _bits | (_contentLength.HasValue ? -9223372036854775808L : 0);
             

src/Kestrel.Core/Internal/Http/HttpParser.cs

@@ -7,6 +7,7 @@ using System.Collections;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using Microsoft.AspNetCore.Protocols.Abstractions;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
@@ -33,7 +34,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         private const byte ByteQuestionMark = (byte)'?';
         private const byte BytePercentage = (byte)'%';
 
-        public unsafe bool ParseRequestLine(TRequestHandler handler, ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
+        public unsafe bool ParseRequestLine(TRequestHandler handler, ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined)
         {
             consumed = buffer.Start;
             examined = buffer.End;
@@ -188,7 +189,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             handler.OnStartLine(method, httpVersion, targetBuffer, pathBuffer, query, customMethod, pathEncoded);
         }
 
-        public unsafe bool ParseHeaders(TRequestHandler handler, ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined, out int consumedBytes)
+        public unsafe bool ParseHeaders(TRequestHandler handler, ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined, out int consumedBytes)
         {
             consumed = buffer.Start;
             examined = buffer.End;
@@ -196,8 +197,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 
             var bufferEnd = buffer.End;
 
-            var reader = BufferReader.Create(buffer);
+            var reader = new BufferReader(buffer);
-            var start = default(BufferReader<ReadOnlyBuffer<byte>>);
+            var start = default(BufferReader);
             var done = false;
 
             try
@@ -418,7 +419,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
-        private static bool TryGetNewLine(ref ReadOnlyBuffer<byte> buffer, out SequencePosition found)
+        private static bool TryGetNewLine(ref ReadOnlySequence<byte> buffer, out SequencePosition found)
         {
             var byteLfPosition = buffer.PositionOf(ByteLF);
             if (byteLfPosition != null)

src/Kestrel.Core/Internal/Http/HttpProtocol.cs

@@ -383,7 +383,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         {
         }
 
-        protected virtual bool BeginRead(out ValueAwaiter<ReadResult> awaitable)
+        protected virtual bool BeginRead(out PipeAwaiter<ReadResult> awaitable)
         {
             awaitable = default;
             return false;
@@ -930,12 +930,13 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 
         private static void WriteChunk(PipeWriter writableBuffer, ReadOnlyMemory<byte> buffer)
         {
-            var writer = OutputWriter.Create(writableBuffer);
+            var writer = new BufferWriter<PipeWriter>(writableBuffer);
             if (buffer.Length > 0)
             {
                 ChunkWriter.WriteBeginChunkBytes(ref writer, buffer.Length);
                 writer.Write(buffer.Span);
                 ChunkWriter.WriteEndChunkBytes(ref writer);
+                writer.Commit();
             }
         }
 

src/Kestrel.Core/Internal/Http/HttpResponseHeaders.cs

@@ -35,9 +35,9 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return GetEnumerator();
         }
 
-        public void CopyTo(ref OutputWriter<PipeWriter> output)
+        internal void CopyTo(ref BufferWriter<PipeWriter> buffer)
         {
-            CopyToFast(ref output);
+            CopyToFast(ref buffer);
             if (MaybeUnknown != null)
             {
                 foreach (var kv in MaybeUnknown)
@@ -46,10 +46,10 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                     {
                         if (value != null)
                         {
-                            output.Write(_CrLf);
+                            buffer.Write(_CrLf);
-                            PipelineExtensions.WriteAsciiNoValidation(ref output, kv.Key);
+                            PipelineExtensions.WriteAsciiNoValidation(ref buffer, kv.Key);
-                            output.Write(_colonSpace);
+                            buffer.Write(_colonSpace);
-                            PipelineExtensions.WriteAsciiNoValidation(ref output, value);
+                            PipelineExtensions.WriteAsciiNoValidation(ref buffer, value);
                         }
                     }
                 }

src/Kestrel.Core/Internal/Http/IHttpParser.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.Buffers;
 using System.Collections;
 
@@ -8,8 +9,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 {
     public interface IHttpParser<TRequestHandler> where TRequestHandler : IHttpHeadersHandler, IHttpRequestLineHandler
     {
-        bool ParseRequestLine(TRequestHandler handler, ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined);
+        bool ParseRequestLine(TRequestHandler handler, ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined);
 
-        bool ParseHeaders(TRequestHandler handler, ReadOnlyBuffer<byte> buffer, out SequencePosition consumed, out SequencePosition examined, out int consumedBytes);
+        bool ParseHeaders(TRequestHandler handler, ReadOnlySequence<byte> buffer, out SequencePosition consumed, out SequencePosition examined, out int consumedBytes);
     }
 }

src/Kestrel.Core/Internal/Http/IHttpProtocolContext.cs

@@ -12,7 +12,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         string ConnectionId { get; set; }
         ServiceContext ServiceContext { get; set; }
         IFeatureCollection ConnectionFeatures { get; set; }
-        MemoryPool MemoryPool { get; set; }
+        MemoryPool<byte> MemoryPool { get; set; }
         IPEndPoint RemoteEndPoint { get; set; }
         IPEndPoint LocalEndPoint { get; set; }
     }

src/Kestrel.Core/Internal/Http/MessageBody.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Buffers;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;

src/Kestrel.Core/Internal/Http/PipelineExtensions.cs

@@ -17,7 +17,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         private static byte[] _numericBytesScratch;
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static ReadOnlySpan<byte> ToSpan(this ReadOnlyBuffer<byte> buffer)
+        public static ReadOnlySpan<byte> ToSpan(this ReadOnlySequence<byte> buffer)
         {
             if (buffer.IsSingleSegment)
             {
@@ -45,7 +45,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return result;
         }
 
-        public unsafe static void WriteAsciiNoValidation(ref this OutputWriter<PipeWriter> buffer, string data)
+        internal static unsafe void WriteAsciiNoValidation(ref this BufferWriter<PipeWriter> buffer, string data)
         {
             if (string.IsNullOrEmpty(data))
             {
@@ -74,7 +74,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public unsafe static void WriteNumeric(ref this OutputWriter<PipeWriter> buffer, ulong number)
+        internal static unsafe void WriteNumeric(ref this BufferWriter<PipeWriter> buffer, ulong number)
         {
             const byte AsciiDigitStart = (byte)'0';
 
@@ -124,7 +124,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
-        private static void WriteNumericMultiWrite(ref this OutputWriter<PipeWriter> buffer, ulong number)
+        private static void WriteNumericMultiWrite(ref this BufferWriter<PipeWriter> buffer, ulong number)
         {
             const byte AsciiDigitStart = (byte)'0';
 
@@ -145,7 +145,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
-        private unsafe static void WriteAsciiMultiWrite(ref this OutputWriter<PipeWriter> buffer, string data)
+        private unsafe static void WriteAsciiMultiWrite(ref this BufferWriter<PipeWriter> buffer, string data)
         {
             var remaining = data.Length;
 
@@ -176,7 +176,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             }
         }
 
-        private unsafe static void EncodeAsciiCharsToBytes(char* input, byte* output, int length)
+        private static unsafe void EncodeAsciiCharsToBytes(char* input, byte* output, int length)
         {
             // Note: Not BIGENDIAN or check for non-ascii
             const int Shift16Shift24 = (1 << 16) | (1 << 24);

src/Kestrel.Core/Internal/Http/UrlDecoder.cs

@@ -0,0 +1,411 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+namespace Microsoft.AspNetCore.Protocols.Abstractions
+{
+    internal class UrlDecoder
+    {
+        static bool[] IsAllowed = new bool[0x7F + 1];
+
+        /// <summary>
+        /// Unescape a URL path
+        /// </summary>
+        /// <param name="source">The byte span represents a UTF8 encoding url path.</param>
+        /// <param name="destination">The byte span where unescaped url path is copied to.</param>
+        /// <returns>The length of the byte sequence of the unescaped url path.</returns>
+        public static int Decode(ReadOnlySpan<byte> source, Span<byte> destination)
+        {
+            if (destination.Length < source.Length)
+            {
+                throw new ArgumentException(
+                    "Lenghth of the destination byte span is less then the source.",
+                    nameof(destination));
+            }
+
+            // This requires the destination span to be larger or equal to source span
+            source.CopyTo(destination);
+            return DecodeInPlace(destination);
+        }
+
+        /// <summary>
+        /// Unescape a URL path in place.
+        /// </summary>
+        /// <param name="buffer">The byte span represents a UTF8 encoding url path.</param>
+        /// <returns>The number of the bytes representing the result.</returns>
+        /// <remarks>
+        /// The unescape is done in place, which means after decoding the result is the subset of
+        /// the input span.
+        /// </remarks>
+        public static int DecodeInPlace(Span<byte> buffer)
+        {
+            // the slot to read the input
+            var sourceIndex = 0;
+
+            // the slot to write the unescaped byte
+            var destinationIndex = 0;
+
+            while (true)
+            {
+                if (sourceIndex == buffer.Length)
+                {
+                    break;
+                }
+
+                if (buffer[sourceIndex] == '%')
+                {
+                    var decodeIndex = sourceIndex;
+
+                    // If decoding process succeeds, the writer iterator will be moved
+                    // to the next write-ready location. On the other hand if the scanned
+                    // percent-encodings cannot be interpreted as sequence of UTF-8 octets,
+                    // these bytes should be copied to output as is.
+                    // The decodeReader iterator is always moved to the first byte not yet
+                    // be scanned after the process. A failed decoding means the chars
+                    // between the reader and decodeReader can be copied to output untouched.
+                    if (!DecodeCore(ref decodeIndex, ref destinationIndex, buffer))
+                    {
+                        Copy(sourceIndex, decodeIndex, ref destinationIndex, buffer);
+                    }
+
+                    sourceIndex = decodeIndex;
+                }
+                else
+                {
+                    buffer[destinationIndex++] = buffer[sourceIndex++];
+                }
+            }
+
+            return destinationIndex;
+        }
+
+        /// <summary>
+        /// Unescape the percent-encodings
+        /// </summary>
+        /// <param name="sourceIndex">The iterator point to the first % char</param>
+        /// <param name="destinationIndex">The place to write to</param>
+        /// <param name="buffer">The byte array</param>
+        private static bool DecodeCore(ref int sourceIndex, ref int destinationIndex, Span<byte> buffer)
+        {
+            // preserves the original head. if the percent-encodings cannot be interpreted as sequence of UTF-8 octets,
+            // bytes from this till the last scanned one will be copied to the memory pointed by writer.
+            var byte1 = UnescapePercentEncoding(ref sourceIndex, buffer);
+            if (byte1 == -1)
+            {
+                return false;
+            }
+
+            if (byte1 == 0)
+            {
+                throw new InvalidOperationException("The path contains null characters.");
+            }
+
+            if (byte1 <= 0x7F)
+            {
+                // first byte < U+007f, it is a single byte ASCII
+                buffer[destinationIndex++] = (byte)byte1;
+                return true;
+            }
+
+            int byte2 = 0, byte3 = 0, byte4 = 0;
+
+            // anticipate more bytes
+            var currentDecodeBits = 0;
+            var byteCount = 1;
+            var expectValueMin = 0;
+            if ((byte1 & 0xE0) == 0xC0)
+            {
+                // 110x xxxx, expect one more byte
+                currentDecodeBits = byte1 & 0x1F;
+                byteCount = 2;
+                expectValueMin = 0x80;
+            }
+            else if ((byte1 & 0xF0) == 0xE0)
+            {
+                // 1110 xxxx, expect two more bytes
+                currentDecodeBits = byte1 & 0x0F;
+                byteCount = 3;
+                expectValueMin = 0x800;
+            }
+            else if ((byte1 & 0xF8) == 0xF0)
+            {
+                // 1111 0xxx, expect three more bytes
+                currentDecodeBits = byte1 & 0x07;
+                byteCount = 4;
+                expectValueMin = 0x10000;
+            }
+            else
+            {
+                // invalid first byte
+                return false;
+            }
+
+            var remainingBytes = byteCount - 1;
+            while (remainingBytes > 0)
+            {
+                // read following three chars
+                if (sourceIndex == buffer.Length)
+                {
+                    return false;
+                }
+
+                var nextSourceIndex = sourceIndex;
+                var nextByte = UnescapePercentEncoding(ref nextSourceIndex, buffer);
+                if (nextByte == -1)
+                {
+                    return false;
+                }
+
+                if ((nextByte & 0xC0) != 0x80)
+                {
+                    // the follow up byte is not in form of 10xx xxxx
+                    return false;
+                }
+
+                currentDecodeBits = (currentDecodeBits << 6) | (nextByte & 0x3F);
+                remainingBytes--;
+
+                if (remainingBytes == 1 && currentDecodeBits >= 0x360 && currentDecodeBits <= 0x37F)
+                {
+                    // this is going to end up in the range of 0xD800-0xDFFF UTF-16 surrogates that
+                    // are not allowed in UTF-8;
+                    return false;
+                }
+
+                if (remainingBytes == 2 && currentDecodeBits >= 0x110)
+                {
+                    // this is going to be out of the upper Unicode bound 0x10FFFF.
+                    return false;
+                }
+
+                sourceIndex = nextSourceIndex;
+                if (byteCount - remainingBytes == 2)
+                {
+                    byte2 = nextByte;
+                }
+                else if (byteCount - remainingBytes == 3)
+                {
+                    byte3 = nextByte;
+                }
+                else if (byteCount - remainingBytes == 4)
+                {
+                    byte4 = nextByte;
+                }
+            }
+
+            if (currentDecodeBits < expectValueMin)
+            {
+                // overlong encoding (e.g. using 2 bytes to encode something that only needed 1).
+                return false;
+            }
+
+            // all bytes are verified, write to the output
+            // TODO: measure later to determine if the performance of following logic can be improved
+            //       the idea is to combine the bytes into short/int and write to span directly to avoid
+            //       range check cost
+            if (byteCount > 0)
+            {
+                buffer[destinationIndex++] = (byte)byte1;
+            }
+            if (byteCount > 1)
+            {
+                buffer[destinationIndex++] = (byte)byte2;
+            }
+            if (byteCount > 2)
+            {
+                buffer[destinationIndex++] = (byte)byte3;
+            }
+            if (byteCount > 3)
+            {
+                buffer[destinationIndex++] = (byte)byte4;
+            }
+
+            return true;
+        }
+
+        private static void Copy(int begin, int end, ref int writer, Span<byte> buffer)
+        {
+            while (begin != end)
+            {
+                buffer[writer++] = buffer[begin++];
+            }
+        }
+
+        /// <summary>
+        /// Read the percent-encoding and try unescape it.
+        ///
+        /// The operation first peek at the character the <paramref name="scan"/>
+        /// iterator points at. If it is % the <paramref name="scan"/> is then
+        /// moved on to scan the following to characters. If the two following
+        /// characters are hexadecimal literals they will be unescaped and the
+        /// value will be returned.
+        ///
+        /// If the first character is not % the <paramref name="scan"/> iterator
+        /// will be removed beyond the location of % and -1 will be returned.
+        ///
+        /// If the following two characters can't be successfully unescaped the
+        /// <paramref name="scan"/> iterator will be move behind the % and -1
+        /// will be returned.
+        /// </summary>
+        /// <param name="scan">The value to read</param>
+        /// <param name="buffer">The byte array</param>
+        /// <returns>The unescaped byte if success. Otherwise return -1.</returns>
+        private static int UnescapePercentEncoding(ref int scan, Span<byte> buffer)
+        {
+            if (buffer[scan++] != '%')
+            {
+                return -1;
+            }
+
+            var probe = scan;
+
+            var value1 = ReadHex(ref probe, buffer);
+            if (value1 == -1)
+            {
+                return -1;
+            }
+
+            var value2 = ReadHex(ref probe, buffer);
+            if (value2 == -1)
+            {
+                return -1;
+            }
+
+            if (SkipUnescape(value1, value2))
+            {
+                return -1;
+            }
+
+            scan = probe;
+            return (value1 << 4) + value2;
+        }
+
+
+        /// <summary>
+        /// Read the next char and convert it into hexadecimal value.
+        ///
+        /// The <paramref name="scan"/> index will be moved to the next
+        /// byte no matter no matter whether the operation successes.
+        /// </summary>
+        /// <param name="scan">The index of the byte in the buffer to read</param>
+        /// <param name="buffer">The byte span from which the hex to be read</param>
+        /// <returns>The hexadecimal value if successes, otherwise -1.</returns>
+        private static int ReadHex(ref int scan, Span<byte> buffer)
+        {
+            if (scan == buffer.Length)
+            {
+                return -1;
+            }
+
+            var value = buffer[scan++];
+            var isHead = ((value >= '0') && (value <= '9')) ||
+                         ((value >= 'A') && (value <= 'F')) ||
+                         ((value >= 'a') && (value <= 'f'));
+
+            if (!isHead)
+            {
+                return -1;
+            }
+
+            if (value <= '9')
+            {
+                return value - '0';
+            }
+            else if (value <= 'F')
+            {
+                return (value - 'A') + 10;
+            }
+            else // a - f
+            {
+                return (value - 'a') + 10;
+            }
+        }
+
+        private static bool SkipUnescape(int value1, int value2)
+        {
+            // skip %2F - '/'
+            if (value1 == 2 && value2 == 15)
+            {
+                return true;
+            }
+
+            return false;
+        }
+
+        static UrlDecoder()
+        {
+            // Unreserved
+            IsAllowed['A'] = true;
+            IsAllowed['B'] = true;
+            IsAllowed['C'] = true;
+            IsAllowed['D'] = true;
+            IsAllowed['E'] = true;
+            IsAllowed['F'] = true;
+            IsAllowed['G'] = true;
+            IsAllowed['H'] = true;
+            IsAllowed['I'] = true;
+            IsAllowed['J'] = true;
+            IsAllowed['K'] = true;
+            IsAllowed['L'] = true;
+            IsAllowed['M'] = true;
+            IsAllowed['N'] = true;
+            IsAllowed['O'] = true;
+            IsAllowed['P'] = true;
+            IsAllowed['Q'] = true;
+            IsAllowed['R'] = true;
+            IsAllowed['S'] = true;
+            IsAllowed['T'] = true;
+            IsAllowed['U'] = true;
+            IsAllowed['V'] = true;
+            IsAllowed['W'] = true;
+            IsAllowed['X'] = true;
+            IsAllowed['Y'] = true;
+            IsAllowed['Z'] = true;
+
+            IsAllowed['a'] = true;
+            IsAllowed['b'] = true;
+            IsAllowed['c'] = true;
+            IsAllowed['d'] = true;
+            IsAllowed['e'] = true;
+            IsAllowed['f'] = true;
+            IsAllowed['g'] = true;
+            IsAllowed['h'] = true;
+            IsAllowed['i'] = true;
+            IsAllowed['j'] = true;
+            IsAllowed['k'] = true;
+            IsAllowed['l'] = true;
+            IsAllowed['m'] = true;
+            IsAllowed['n'] = true;
+            IsAllowed['o'] = true;
+            IsAllowed['p'] = true;
+            IsAllowed['q'] = true;
+            IsAllowed['r'] = true;
+            IsAllowed['s'] = true;
+            IsAllowed['t'] = true;
+            IsAllowed['u'] = true;
+            IsAllowed['v'] = true;
+            IsAllowed['w'] = true;
+            IsAllowed['x'] = true;
+            IsAllowed['y'] = true;
+            IsAllowed['z'] = true;
+
+            IsAllowed['0'] = true;
+            IsAllowed['1'] = true;
+            IsAllowed['2'] = true;
+            IsAllowed['3'] = true;
+            IsAllowed['4'] = true;
+            IsAllowed['5'] = true;
+            IsAllowed['6'] = true;
+            IsAllowed['7'] = true;
+            IsAllowed['8'] = true;
+            IsAllowed['9'] = true;
+
+            IsAllowed['-'] = true;
+            IsAllowed['_'] = true;
+            IsAllowed['.'] = true;
+            IsAllowed['~'] = true;
+        }
+    }
+}

src/Kestrel.Core/Internal/Http2/Http2Connection.cs

@@ -215,7 +215,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
             }
         }
 
-        private bool ParsePreface(ReadOnlyBuffer<byte> readableBuffer, out SequencePosition consumed, out SequencePosition examined)
+        private bool ParsePreface(ReadOnlySequence<byte> readableBuffer, out SequencePosition consumed, out SequencePosition examined)
         {
             consumed = readableBuffer.Start;
             examined = readableBuffer.End;

src/Kestrel.Core/Internal/Http2/Http2ConnectionContext.cs

@@ -13,7 +13,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
         public string ConnectionId { get; set; }
         public ServiceContext ServiceContext { get; set; }
         public IFeatureCollection ConnectionFeatures { get; set; }
-        public MemoryPool MemoryPool { get; set; }
+        public MemoryPool<byte> MemoryPool { get; set; }
         public IPEndPoint LocalEndPoint { get; set; }
         public IPEndPoint RemoteEndPoint { get; set; }
 

src/Kestrel.Core/Internal/Http2/Http2FrameReader.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.Buffers;
 using System.Collections;
 
@@ -8,7 +9,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
 {
     public static class Http2FrameReader
     {
-        public static bool ReadFrame(ReadOnlyBuffer<byte> readableBuffer, Http2Frame frame, out SequencePosition consumed, out SequencePosition examined)
+        public static bool ReadFrame(ReadOnlySequence<byte> readableBuffer, Http2Frame frame, out SequencePosition consumed, out SequencePosition examined)
         {
             consumed = readableBuffer.Start;
             examined = readableBuffer.End;

src/Kestrel.Core/Internal/Http2/Http2FrameWriter.cs

@@ -190,7 +190,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
             }
 
             _outputWriter.Write(data);
-            _outputWriter.Commit();
         }
 
         // Must be called with _writeLock

src/Kestrel.Core/Internal/Http2/Http2Stream.cs

@@ -83,14 +83,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
             {
                 if (data.Count > 0)
                 {
-                    try
+                    RequestBodyPipe.Writer.Write(data);
-                    {
-                        RequestBodyPipe.Writer.Write(data);
-                    }
-                    finally
-                    {
-                        RequestBodyPipe.Writer.Commit();
-                    }
 
                     RequestBodyStarted = true;
                     await RequestBodyPipe.Writer.FlushAsync();

src/Kestrel.Core/Internal/Http2/Http2StreamContext.cs

@@ -14,7 +14,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
         public int StreamId { get; set; }
         public ServiceContext ServiceContext { get; set; }
         public IFeatureCollection ConnectionFeatures { get; set; }
-        public MemoryPool MemoryPool { get; set; }
+        public MemoryPool<byte> MemoryPool { get; set; }
         public IPEndPoint RemoteEndPoint { get; set; }
         public IPEndPoint LocalEndPoint { get; set; }
         public IHttp2StreamLifetimeHandler StreamLifetimeHandler { get; set; }

src/Kestrel.Core/Internal/HttpConnection.cs

@@ -68,7 +68,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
         public IPEndPoint LocalEndPoint => _context.LocalEndPoint;
         public IPEndPoint RemoteEndPoint => _context.RemoteEndPoint;
 
-        private MemoryPool MemoryPool => _context.MemoryPool;
+        private MemoryPool<byte> MemoryPool => _context.MemoryPool;
 
         // Internal for testing
         internal PipeOptions AdaptedInputPipeOptions => new PipeOptions

src/Kestrel.Core/Internal/HttpConnectionContext.cs

@@ -18,7 +18,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
         public ServiceContext ServiceContext { get; set; }
         public IFeatureCollection ConnectionFeatures { get; set; }
         public IList<IConnectionAdapter> ConnectionAdapters { get; set; }
-        public MemoryPool MemoryPool { get; set; }
+        public MemoryPool<byte> MemoryPool { get; set; }
         public IPEndPoint LocalEndPoint { get; set; }
         public IPEndPoint RemoteEndPoint { get; set; }
         public IDuplexPipe Transport { get; set; }

src/Kestrel.Core/Internal/Infrastructure/KestrelThreadPool.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.IO.Pipelines;
 using System.Threading;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure

src/Kestrel.Core/Kestrel.Core.csproj

@@ -21,6 +21,7 @@
     <PackageReference Include="Microsoft.Extensions.Options" Version="$(MicrosoftExtensionsOptionsPackageVersion)" />
     <PackageReference Include="System.Threading.Tasks.Extensions" Version="$(SystemThreadingTasksExtensionsPackageVersion)" />
     <PackageReference Include="System.Memory" Version="$(SystemMemoryPackageVersion)" />
+    <PackageReference Include="Microsoft.Extensions.Buffers.Sources" Version="$(MicrosoftExtensionsBuffersSourcesPackageVersion)" PrivateAssets="All" />
     <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="$(SystemRuntimeCompilerServicesUnsafePackageVersion)" />
     <PackageReference Include="System.Security.Cryptography.Cng" Version="$(SystemSecurityCryptographyCngPackageVersion)" />
   </ItemGroup>

src/Kestrel.Transport.Abstractions/Internal/KestrelMemoryPool.cs

@@ -0,0 +1,12 @@
+// 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.Buffers;
+
+namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal
+{
+    public static class KestrelMemoryPool
+    {
+        public static MemoryPool<byte> Create() => new SlabMemoryPool();
+    }
+}

src/Kestrel.Transport.Abstractions/Internal/TransportConnection.Features.cs

@@ -95,7 +95,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal
             set => LocalPort = value;
         }
 
-        MemoryPool IConnectionTransportFeature.MemoryPool => MemoryPool;
+        MemoryPool<byte> IConnectionTransportFeature.MemoryPool => MemoryPool;
 
         IDuplexPipe IConnectionTransportFeature.Transport
         {

src/Kestrel.Transport.Abstractions/Internal/TransportConnection.cs

@@ -21,7 +21,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal
 
         public string ConnectionId { get; set; }
 
-        public virtual MemoryPool MemoryPool { get; }
+        public virtual MemoryPool<byte> MemoryPool { get; }
         public virtual PipeScheduler InputWriterScheduler { get; }
         public virtual PipeScheduler OutputReaderScheduler { get; }
 

src/Kestrel.Transport.Abstractions/Kestrel.Transport.Abstractions.csproj

@@ -15,5 +15,8 @@
   <ItemGroup>
     <ProjectReference Include="..\Protocols.Abstractions\Protocols.Abstractions.csproj" />
   </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Buffers.Sources" Version="$(MicrosoftExtensionsBuffersSourcesPackageVersion)" PrivateAssets="All" />
+  </ItemGroup>
 
 </Project>

src/Kestrel.Transport.Libuv/Internal/LibuvConnection.cs

@@ -122,7 +122,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
             {
                 // EAGAIN/EWOULDBLOCK so just return the buffer.
                 // http://docs.libuv.org/en/v1.x/stream.html#c.uv_read_cb
-                Input.Commit();
             }
             else if (status > 0)
             {
@@ -141,7 +140,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
             else
             {
                 // Given a negative status, it's possible that OnAlloc wasn't called.
-                Input.Commit();
                 _socket.ReadStop();
 
                 IOException error = null;
@@ -175,7 +173,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
             _bufferHandle.Dispose();
         }
 
-        private async Task ApplyBackpressureAsync(ValueAwaiter<FlushResult> flushTask)
+        private async Task ApplyBackpressureAsync(PipeAwaiter<FlushResult> flushTask)
         {
             Log.ConnectionPause(ConnectionId);
             _socket.ReadStop();
@@ -183,7 +181,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
             var result = await flushTask;
 
             // If the reader isn't complete or cancelled then resume reading
-            if (!result.IsCompleted && !result.IsCancelled)
+            if (!result.IsCompleted && !result.IsCanceled)
             {
                 Log.ConnectionResume(ConnectionId);
                 StartReading();

src/Kestrel.Transport.Libuv/Internal/LibuvConnectionContext.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Buffers;
+using System.IO.Pipelines;
 using System.Threading;
 using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 
@@ -16,7 +17,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
 
         public ListenerContext ListenerContext { get; set; }
 
-        public override MemoryPool MemoryPool => ListenerContext.Thread.MemoryPool;
+        public override MemoryPool<byte> MemoryPool => ListenerContext.Thread.MemoryPool;
         public override PipeScheduler InputWriterScheduler => ListenerContext.Thread;
         public override PipeScheduler OutputReaderScheduler => ListenerContext.Thread;
     }

src/Kestrel.Transport.Libuv/Internal/LibuvOutputConsumer.cs

@@ -55,7 +55,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
 
                 try
                 {
-                    if (result.IsCancelled)
+                    if (result.IsCanceled)
                     {
                         break;
                     }

src/Kestrel.Transport.Libuv/Internal/LibuvThread.cs

@@ -5,10 +5,12 @@ using System;
 using System.Buffers;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.IO.Pipelines;
 using System.Runtime.ExceptionServices;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.Networking;
 using Microsoft.Extensions.Logging;
 
@@ -55,7 +57,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
 #endif
             QueueCloseHandle = PostCloseHandle;
             QueueCloseAsyncHandle = EnqueueCloseHandle;
-            MemoryPool = new MemoryPool();
+            MemoryPool = KestrelMemoryPool.Create();
             WriteReqPool = new WriteReqPool(this, _log);
         }
 
@@ -68,7 +70,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
 
         public UvLoopHandle Loop { get { return _loop; } }
 
-        public MemoryPool MemoryPool { get; }
+        public MemoryPool<byte> MemoryPool { get; }
 
         public WriteReqPool WriteReqPool { get; }
 

src/Kestrel.Transport.Libuv/Internal/Networking/UvWriteReq.cs

@@ -48,7 +48,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.Networkin
             _bufs = handle + requestSize;
         }
 
-        public LibuvAwaitable<UvWriteReq> WriteAsync(UvStreamHandle handle, ReadOnlyBuffer<byte> buffer)
+        public LibuvAwaitable<UvWriteReq> WriteAsync(UvStreamHandle handle, ReadOnlySequence<byte> buffer)
         {
             Write(handle, buffer, LibuvAwaitable<UvWriteReq>.Callback, _awaitable);
             return _awaitable;
@@ -62,7 +62,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.Networkin
 
         private unsafe void Write(
             UvStreamHandle handle,
-            ReadOnlyBuffer<byte> buffer,
+            ReadOnlySequence<byte> buffer,
             Action<UvWriteReq, int, UvException, object> callback,
             object state)
         {

src/Kestrel.Transport.Sockets/Internal/SocketConnection.cs

@@ -5,6 +5,7 @@ using System;
 using System.Buffers;
 using System.Diagnostics;
 using System.IO;
+using System.IO.Pipelines;
 using System.Net;
 using System.Net.Sockets;
 using System.Threading.Tasks;
@@ -26,7 +27,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.Internal
 
         private volatile bool _aborted;
 
-        internal SocketConnection(Socket socket, MemoryPool memoryPool, ISocketsTrace trace)
+        internal SocketConnection(Socket socket, MemoryPool<byte> memoryPool, ISocketsTrace trace)
         {
             Debug.Assert(socket != null);
             Debug.Assert(memoryPool != null);
@@ -49,7 +50,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.Internal
             _sender = new SocketSender(_socket);
         }
 
-        public override MemoryPool MemoryPool { get; }
+        public override MemoryPool<byte> MemoryPool { get; }
         public override PipeScheduler InputWriterScheduler => PipeScheduler.Inline;
         public override PipeScheduler OutputReaderScheduler => PipeScheduler.ThreadPool;
 
@@ -102,24 +103,18 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.Internal
                     // Ensure we have some reasonable amount of buffer space
                     var buffer = Input.GetMemory(MinAllocBufferSize);
 
-                    try
+                    var bytesReceived = await _receiver.ReceiveAsync(buffer);
-                    {
-                        var bytesReceived = await _receiver.ReceiveAsync(buffer);
 
-                        if (bytesReceived == 0)
+                    if (bytesReceived == 0)
-                        {
-                            // FIN
-                            _trace.ConnectionReadFin(ConnectionId);
-                            break;
-                        }
-
-                        Input.Advance(bytesReceived);
-                    }
-                    finally
                     {
-                        Input.Commit();
+                        // FIN
+                        _trace.ConnectionReadFin(ConnectionId);
+                        break;
                     }
 
+                    Input.Advance(bytesReceived);
+
+
                     var flushTask = Input.FlushAsync();
 
                     if (!flushTask.IsCompleted)
@@ -197,7 +192,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.Internal
                     var result = await Output.ReadAsync();
                     var buffer = result.Buffer;
 
-                    if (result.IsCancelled)
+                    if (result.IsCanceled)
                     {
                         break;
                     }

src/Kestrel.Transport.Sockets/Internal/SocketSender.cs

@@ -25,7 +25,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.Internal
             _eventArgs.Completed += (_, e) => ((SocketAwaitable)e.UserToken).Complete(e.BytesTransferred, e.SocketError);
         }
 
-        public SocketAwaitable SendAsync(ReadOnlyBuffer<byte> buffers)
+        public SocketAwaitable SendAsync(ReadOnlySequence<byte> buffers)
         {
             if (buffers.IsSingleSegment)
             {
@@ -74,7 +74,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.Internal
             return _awaitable;
         }
 
-        private List<ArraySegment<byte>> GetBufferList(ReadOnlyBuffer<byte> buffer)
+        private List<ArraySegment<byte>> GetBufferList(ReadOnlySequence<byte> buffer)
         {
             Debug.Assert(!buffer.IsEmpty);
             Debug.Assert(!buffer.IsSingleSegment);

src/Kestrel.Transport.Sockets/SocketTransport.cs

@@ -19,7 +19,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets
 {
     internal sealed class SocketTransport : ITransport
     {
-        private readonly MemoryPool _memoryPool = new MemoryPool();
+        private readonly MemoryPool<byte> _memoryPool = KestrelMemoryPool.Create();
         private readonly IEndPointInformation _endPointInformation;
         private readonly IConnectionHandler _handler;
         private readonly IApplicationLifetime _appLifetime;

src/Protocols.Abstractions/DuplexPipe.cs

@@ -18,7 +18,7 @@ namespace System.IO.Pipelines
         {
         }
 
-        public static DuplexPipePair CreateConnectionPair(MemoryPool memoryPool)
+        public static DuplexPipePair CreateConnectionPair(MemoryPool<byte> memoryPool)
         {
             return CreateConnectionPair(new PipeOptions(memoryPool), new PipeOptions(memoryPool));
         }

src/Protocols.Abstractions/Features/IConnectionTransportFeature.cs

@@ -6,7 +6,7 @@ namespace Microsoft.AspNetCore.Protocols.Features
 {
     public interface IConnectionTransportFeature
     {
-        MemoryPool MemoryPool { get; }
+        MemoryPool<byte> MemoryPool { get; }
 
         IDuplexPipe Transport { get; set; }
 

src/Protocols.Abstractions/Protocols.Abstractions.csproj

@@ -17,7 +17,6 @@
     <PackageReference Include="System.Numerics.Vectors" Version="$(SystemNumericsVectorsPackageVersion)" />
     <PackageReference Include="System.Buffers" Version="$(SystemBuffersPackageVersion)" />
     <PackageReference Include="System.IO.Pipelines" Version="$(SystemIOPipelinesPackageVersion)" />
-    <PackageReference Include="System.Text.Encodings.Web.Utf8" Version="$(SystemTextEncodingsWebUtf8PackageVersion)" />
     <PackageReference Include="System.Memory" Version="$(SystemMemoryPackageVersion)" />
     <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="$(SystemRuntimeCompilerServicesUnsafePackageVersion)" />
   </ItemGroup>

test/Kestrel.Core.Tests/ConnectionHandlerTests.cs

@@ -7,6 +7,8 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Protocols.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
+using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 using Xunit;
 
@@ -51,7 +53,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
                 Set<IConnectionTransportFeature>(this);
             }
 
-            public MemoryPool MemoryPool { get; } = new MemoryPool();
+            public MemoryPool<byte> MemoryPool { get; } = KestrelMemoryPool.Create();
 
             public IDuplexPipe Transport { get; set; }
             public IDuplexPipe Application { get; set; }

test/Kestrel.Core.Tests/Http1ConnectionTests.cs

@@ -17,6 +17,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Core.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Primitives;
@@ -32,14 +33,14 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         private readonly TestHttp1Connection _http1Connection;
         private readonly ServiceContext _serviceContext;
         private readonly Http1ConnectionContext _http1ConnectionContext;
-        private readonly MemoryPool _pipelineFactory;
+        private readonly MemoryPool<byte> _pipelineFactory;
         private SequencePosition _consumed;
         private SequencePosition _examined;
         private Mock<ITimeoutControl> _timeoutControl;
 
         public Http1ConnectionTests()
         {
-            _pipelineFactory = new MemoryPool();
+            _pipelineFactory = KestrelMemoryPool.Create();
             var pair = DuplexPipe.CreateConnectionPair(_pipelineFactory);
 
             _transport = pair.Transport;
@@ -803,7 +804,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             _http1Connection.NextMessageBody = mockMessageBody.Object;
 
             var requestProcessingTask = _http1Connection.ProcessRequestsAsync(httpApplication);
-            
+
             var data = Encoding.ASCII.GetBytes("POST / HTTP/1.1\r\nHost:\r\nConnection: close\r\ncontent-length: 1\r\n\r\n");
             await _application.Output.WriteAsync(data);
             await requestProcessingTask.TimeoutAfter(TestConstants.DefaultTimeout);

test/Kestrel.Core.Tests/Http2ConnectionTests.cs

@@ -18,6 +18,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2.HPack;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 using Xunit;
 
@@ -93,7 +94,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         private static readonly byte[] _noData = new byte[0];
         private static readonly byte[] _maxData = Encoding.ASCII.GetBytes(new string('a', Http2Frame.MinAllowedMaxFrameSize));
 
-        private readonly MemoryPool _memoryPool = new MemoryPool();
+        private readonly MemoryPool<byte> _memoryPool = KestrelMemoryPool.Create();
         private readonly DuplexPipe.DuplexPipePair _pair;
         private readonly TestApplicationErrorLogger _logger;
         private readonly Http2ConnectionContext _connectionContext;

test/Kestrel.Core.Tests/HttpConnectionTests.cs

@@ -10,6 +10,7 @@ using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Adapter.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 using Moq;
 using Xunit;
@@ -18,13 +19,13 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
 {
     public class HttpConnectionTests : IDisposable
     {
-        private readonly MemoryPool _memoryPool;
+        private readonly MemoryPool<byte> _memoryPool;
         private readonly HttpConnectionContext _httpConnectionContext;
         private readonly HttpConnection _httpConnection;
 
         public HttpConnectionTests()
         {
-            _memoryPool = new MemoryPool();
+            _memoryPool = KestrelMemoryPool.Create();
             var pair = DuplexPipe.CreateConnectionPair(_memoryPool);
 
             _httpConnectionContext = new HttpConnectionContext

test/Kestrel.Core.Tests/HttpParserTests.cs

@@ -34,7 +34,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             string expectedVersion)
         {
             var parser = CreateParser(Mock.Of<IKestrelTrace>());
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(requestLine));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(requestLine));
             var requestHandler = new RequestHandler();
 
             Assert.True(parser.ParseRequestLine(requestHandler, buffer, out var consumed, out var examined));
@@ -53,7 +53,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void ParseRequestLineReturnsFalseWhenGivenIncompleteRequestLines(string requestLine)
         {
             var parser = CreateParser(Mock.Of<IKestrelTrace>());
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(requestLine));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(requestLine));
             var requestHandler = new RequestHandler();
 
             Assert.False(parser.ParseRequestLine(requestHandler, buffer, out var consumed, out var examined));
@@ -64,7 +64,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void ParseRequestLineDoesNotConsumeIncompleteRequestLine(string requestLine)
         {
             var parser = CreateParser(Mock.Of<IKestrelTrace>());
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(requestLine));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(requestLine));
             var requestHandler = new RequestHandler();
 
             Assert.False(parser.ParseRequestLine(requestHandler, buffer, out var consumed, out var examined));
@@ -83,7 +83,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
                 .Returns(true);
 
             var parser = CreateParser(mockTrace.Object);
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(requestLine));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(requestLine));
             var requestHandler = new RequestHandler();
 
             var exception = Assert.Throws<BadHttpRequestException>(() =>
@@ -105,7 +105,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
                 .Returns(true);
 
             var parser = CreateParser(mockTrace.Object);
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(requestLine));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(requestLine));
             var requestHandler = new RequestHandler();
 
             var exception = Assert.Throws<BadHttpRequestException>(() =>
@@ -127,7 +127,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
                 .Returns(true);
 
             var parser = CreateParser(mockTrace.Object);
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(requestLine));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(requestLine));
             var requestHandler = new RequestHandler();
 
             var exception = Assert.Throws<BadHttpRequestException>(() =>
@@ -178,7 +178,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         {
             var parser = CreateParser(Mock.Of<IKestrelTrace>());
 
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(rawHeaders));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(rawHeaders));
             var requestHandler = new RequestHandler();
             Assert.False(parser.ParseHeaders(requestHandler, buffer, out var consumed, out var examined, out var consumedBytes));
         }
@@ -203,7 +203,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         {
             var parser = CreateParser(Mock.Of<IKestrelTrace>());
 
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(rawHeaders));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(rawHeaders));
             var requestHandler = new RequestHandler();
             parser.ParseHeaders(requestHandler, buffer, out var consumed, out var examined, out var consumedBytes);
 
@@ -293,7 +293,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             var parser = CreateParser(Mock.Of<IKestrelTrace>());
 
             const string headerLine = "Header: value\r\n\r";
-            var buffer1 = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(headerLine));
+            var buffer1 = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(headerLine));
             var requestHandler = new RequestHandler();
             Assert.False(parser.ParseHeaders(requestHandler, buffer1, out var consumed, out var examined, out var consumedBytes));
 
@@ -301,7 +301,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             Assert.Equal(buffer1.End, examined);
             Assert.Equal(headerLine.Length - 1, consumedBytes);
 
-            var buffer2 = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes("\r\n"));
+            var buffer2 = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes("\r\n"));
             Assert.True(parser.ParseHeaders(requestHandler, buffer2, out consumed, out examined, out consumedBytes));
 
             Assert.True(buffer2.Slice(consumed).IsEmpty);
@@ -319,7 +319,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
                 .Returns(true);
 
             var parser = CreateParser(mockTrace.Object);
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(rawHeaders));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(rawHeaders));
             var requestHandler = new RequestHandler();
 
             var exception = Assert.Throws<BadHttpRequestException>(() =>
@@ -340,7 +340,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             var parser = CreateParser(mockTrace.Object);
 
             // Invalid request line
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes("GET % HTTP/1.1\r\n"));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes("GET % HTTP/1.1\r\n"));
             var requestHandler = new RequestHandler();
 
             var exception = Assert.Throws<BadHttpRequestException>(() =>
@@ -350,7 +350,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             Assert.Equal(StatusCodes.Status400BadRequest, (exception as BadHttpRequestException).StatusCode);
 
             // Unrecognized HTTP version
-            buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes("GET / HTTP/1.2\r\n"));
+            buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes("GET / HTTP/1.2\r\n"));
 
             exception = Assert.Throws<BadHttpRequestException>(() =>
                 parser.ParseRequestLine(requestHandler, buffer, out var consumed, out var examined));
@@ -359,7 +359,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             Assert.Equal(StatusCodes.Status505HttpVersionNotsupported, (exception as BadHttpRequestException).StatusCode);
 
             // Invalid request header
-            buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes("Header: value\n\r\n"));
+            buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes("Header: value\n\r\n"));
 
             exception = Assert.Throws<BadHttpRequestException>(() =>
                 parser.ParseHeaders(requestHandler, buffer, out var consumed, out var examined, out var consumedBytes));
@@ -388,7 +388,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             string expectedHeaderValue)
         {
             var parser = CreateParser(Mock.Of<IKestrelTrace>());
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes($"{headerName}:{rawHeaderValue}\r\n"));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes($"{headerName}:{rawHeaderValue}\r\n"));
 
             var requestHandler = new RequestHandler();
             parser.ParseHeaders(requestHandler, buffer, out var consumed, out var examined, out var consumedBytes);
@@ -406,7 +406,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             Assert.True(expectedHeaderNames.Count() == expectedHeaderValues.Count(), $"{nameof(expectedHeaderNames)} and {nameof(expectedHeaderValues)} sizes must match");
 
             var parser = CreateParser(Mock.Of<IKestrelTrace>());
-            var buffer = new ReadOnlyBuffer<byte>(Encoding.ASCII.GetBytes(rawHeaders));
+            var buffer = new ReadOnlySequence<byte>(Encoding.ASCII.GetBytes(rawHeaders));
 
             var requestHandler = new RequestHandler();
             parser.ParseHeaders(requestHandler, buffer, out var consumed, out var examined, out var consumedBytes);
@@ -466,7 +466,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             }
         }
 
-        private static ReadOnlyBuffer<byte> CreateBuffer(params string[] inputs)
+        private static ReadOnlySequence<byte> CreateBuffer(params string[] inputs)
         {
             var buffers = new byte[inputs.Length][];
             for (int i = 0; i < inputs.Length; i++)
@@ -477,7 +477,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         }
 
         // Copied from https://github.com/dotnet/corefx/blob/master/src/System.Memory/tests/ReadOnlyBuffer/ReadOnlySequenceFactory.cs
-        private static ReadOnlyBuffer<byte> CreateBuffer(params byte[][] inputs)
+        private static ReadOnlySequence<byte> CreateBuffer(params byte[][] inputs)
         {
             if (inputs == null || inputs.Length == 0)
             {
@@ -516,7 +516,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
                 i++;
             } while (i < inputs.Length);
 
-            return new ReadOnlyBuffer<byte>(first, 0, last, last.Memory.Length);
+            return new ReadOnlySequence<byte>(first, 0, last, last.Memory.Length);
         }
 
         // Copied from https://github.com/dotnet/corefx/blob/master/src/System.Memory/tests/ReadOnlyBuffer/BufferSegment.cs

test/Kestrel.Core.Tests/HttpProtocolFeatureCollectionTests.cs

@@ -10,6 +10,7 @@ using Microsoft.AspNetCore.Server.Kestrel.Core.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 using Moq;
 using Xunit;
@@ -23,14 +24,14 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         private readonly TestHttp1Connection _http1Connection;
         private readonly ServiceContext _serviceContext;
         private readonly Http1ConnectionContext _http1ConnectionContext;
-        private readonly MemoryPool _pipelineFactory;
+        private readonly MemoryPool<byte> _pipelineFactory;
         private Mock<ITimeoutControl> _timeoutControl;
 
         private readonly IFeatureCollection _collection;
 
         public HttpProtocolFeatureCollectionTests()
         {
-            _pipelineFactory = new MemoryPool();
+            _pipelineFactory = KestrelMemoryPool.Create();
             var pair = DuplexPipe.CreateConnectionPair(_pipelineFactory);
 
             _transport = pair.Transport;

test/Kestrel.Core.Tests/HttpResponseHeadersTests.cs

@@ -9,6 +9,7 @@ using System.IO.Pipelines;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 using Microsoft.Extensions.Primitives;
 using Xunit;
@@ -20,7 +21,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         [Fact]
         public void InitialDictionaryIsEmpty()
         {
-            using (var memoryPool = new MemoryPool())
+            using (var memoryPool = KestrelMemoryPool.Create())
             {
                 var pair = DuplexPipe.CreateConnectionPair(memoryPool);
                 var http1ConnectionContext = new Http1ConnectionContext

test/Kestrel.Core.Tests/OutputProducerTests.cs

@@ -7,6 +7,7 @@ using System.IO.Pipelines;
 using System.Threading;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 using Moq;
 using Xunit;
@@ -15,11 +16,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
 {
     public class OutputProducerTests : IDisposable
     {
-        private readonly MemoryPool _memoryPool;
+        private readonly MemoryPool<byte> _memoryPool;
 
         public OutputProducerTests()
         {
-            _memoryPool = new MemoryPool();
+            _memoryPool = KestrelMemoryPool.Create();
         }
 
         public void Dispose()

test/Kestrel.Core.Tests/PipeOptionsTests.cs

@@ -2,9 +2,11 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Buffers;
+using System.IO.Pipelines;
 using System.Threading;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 using Moq;
 using Xunit;
@@ -24,7 +26,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             serviceContext.ThreadPool = new LoggingThreadPool(null);
 
             var mockScheduler = Mock.Of<PipeScheduler>();
-            var outputPipeOptions = ConnectionHandler.GetOutputPipeOptions(serviceContext, new MemoryPool(), readerScheduler: mockScheduler);
+            var outputPipeOptions = ConnectionHandler.GetOutputPipeOptions(serviceContext, KestrelMemoryPool.Create(), readerScheduler: mockScheduler);
 
             Assert.Equal(expectedMaximumSizeLow, outputPipeOptions.ResumeWriterThreshold);
             Assert.Equal(expectedMaximumSizeHigh, outputPipeOptions.PauseWriterThreshold);
@@ -42,7 +44,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             serviceContext.ThreadPool = new LoggingThreadPool(null);
 
             var mockScheduler = Mock.Of<PipeScheduler>();
-            var inputPipeOptions = ConnectionHandler.GetInputPipeOptions(serviceContext, new MemoryPool(), writerScheduler: mockScheduler);
+            var inputPipeOptions = ConnectionHandler.GetInputPipeOptions(serviceContext, KestrelMemoryPool.Create(), writerScheduler: mockScheduler);
 
             Assert.Equal(expectedMaximumSizeLow, inputPipeOptions.ResumeWriterThreshold);
             Assert.Equal(expectedMaximumSizeHigh, inputPipeOptions.PauseWriterThreshold);

test/Kestrel.Core.Tests/PipelineExtensionTests.cs

@@ -6,6 +6,7 @@ using System.Buffers;
 using System.IO.Pipelines;
 using System.Text;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
@@ -16,7 +17,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         private const int _ulongMaxValueLength = 20;
 
         private readonly Pipe _pipe;
-        private readonly MemoryPool _memoryPool = new MemoryPool();
+        private readonly MemoryPool<byte> _memoryPool = KestrelMemoryPool.Create();
 
         public PipelineExtensionTests()
         {
@@ -35,8 +36,9 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void WritesNumericToAscii(ulong number)
         {
             var writerBuffer = _pipe.Writer;
-            var writer = OutputWriter.Create(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             writer.WriteNumeric(number);
+            writer.Commit();
             writerBuffer.FlushAsync().GetAwaiter().GetResult();
 
             var reader = _pipe.Reader.ReadAsync().GetAwaiter().GetResult();
@@ -52,7 +54,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void WritesNumericAcrossSpanBoundaries(int gapSize)
         {
             var writerBuffer = _pipe.Writer;
-            var writer = OutputWriter.Create(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             // almost fill up the first block
             var spacer = new byte[writer.Span.Length - gapSize];
             writer.Write(spacer);
@@ -60,7 +62,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             var bufferLength = writer.Span.Length;
             writer.WriteNumeric(ulong.MaxValue);
             Assert.NotEqual(bufferLength, writer.Span.Length);
-
+            writer.Commit();
             writerBuffer.FlushAsync().GetAwaiter().GetResult();
 
             var reader = _pipe.Reader.ReadAsync().GetAwaiter().GetResult();
@@ -83,8 +85,9 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void EncodesAsAscii(string input, byte[] expected)
         {
             var writerBuffer = _pipe.Writer;
-            var writer = OutputWriter.Create(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             writer.WriteAsciiNoValidation(input);
+            writer.Commit();
             writerBuffer.FlushAsync().GetAwaiter().GetResult();
             var reader = _pipe.Reader.ReadAsync().GetAwaiter().GetResult();
 
@@ -110,8 +113,9 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             // WriteAscii doesn't validate if characters are in the ASCII range
             // but it shouldn't produce more than one byte per character
             var writerBuffer = _pipe.Writer;
-            var writer = OutputWriter.Create(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             writer.WriteAsciiNoValidation(input);
+            writer.Commit();
             writerBuffer.FlushAsync().GetAwaiter().GetResult();
             var reader = _pipe.Reader.ReadAsync().GetAwaiter().GetResult();
 
@@ -123,11 +127,12 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         {
             const byte maxAscii = 0x7f;
             var writerBuffer = _pipe.Writer;
-            var writer = OutputWriter.Create(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             for (var i = 0; i < maxAscii; i++)
             {
                 writer.WriteAsciiNoValidation(new string((char)i, 1));
             }
+            writer.Commit();
             writerBuffer.FlushAsync().GetAwaiter().GetResult();
 
             var reader = _pipe.Reader.ReadAsync().GetAwaiter().GetResult();
@@ -152,7 +157,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         {
             var testString = new string(' ', stringLength);
             var writerBuffer = _pipe.Writer;
-            var writer = OutputWriter.Create(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             // almost fill up the first block
             var spacer = new byte[writer.Span.Length - gapSize];
             writer.Write(spacer);
@@ -161,7 +166,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             var bufferLength = writer.Span.Length;
             writer.WriteAsciiNoValidation(testString);
             Assert.NotEqual(bufferLength, writer.Span.Length);
-
+            writer.Commit();
             writerBuffer.FlushAsync().GetAwaiter().GetResult();
 
             var reader = _pipe.Reader.ReadAsync().GetAwaiter().GetResult();

test/Kestrel.Core.Tests/TestInput.cs

@@ -5,9 +5,11 @@ using System;
 using System.Buffers;
 using System.IO.Pipelines;
 using System.Text;
+using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Testing;
 using Moq;
 
@@ -15,11 +17,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
 {
     class TestInput : IDisposable
     {
-        private MemoryPool _memoryPool;
+        private MemoryPool<byte> _memoryPool;
 
         public TestInput()
         {
-            _memoryPool = new MemoryPool();
+            _memoryPool = KestrelMemoryPool.Create();
             var pair = DuplexPipe.CreateConnectionPair(_memoryPool);
             Transport = pair.Transport;
             Application = pair.Application;
@@ -49,7 +51,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void Add(string text)
         {
             var data = Encoding.ASCII.GetBytes(text);
-            Application.Output.WriteAsync(data).Wait();
+            async Task Write() => await Application.Output.WriteAsync(data);
+            Write().Wait();
         }
 
         public void Fin()

test/Kestrel.Transport.Libuv.Tests/LibuvOutputConsumerTests.cs

@@ -11,6 +11,7 @@ using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure;
+using Microsoft.AspNetCore.Server.Kestrel.Transport.Abstractions.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal;
 using Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.Networking;
 using Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests.TestHelpers;
@@ -22,7 +23,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests
 {
     public class LibuvOutputConsumerTests : IDisposable
     {
-        private readonly MemoryPool _memoryPool;
+        private readonly MemoryPool<byte> _memoryPool;
         private readonly MockLibuv _mockLibuv;
         private readonly LibuvThread _libuvThread;
 
@@ -38,7 +39,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests
 
         public LibuvOutputConsumerTests()
         {
-            _memoryPool = new MemoryPool();
+            _memoryPool = KestrelMemoryPool.Create();
             _mockLibuv = new MockLibuv();
 
             var libuvTransport = new LibuvTransport(_mockLibuv, new TestLibuvTransportContext(), new ListenOptions((ulong)0));
@@ -340,6 +341,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests
                 (
                     pool: _memoryPool,
                     readerScheduler: _libuvThread,
+                    writerScheduler: PipeScheduler.Inline,
                     pauseWriterThreshold: maxResponseBufferSize,
                     resumeWriterThreshold: maxResponseBufferSize
                 );

test/Kestrel.Transport.Libuv.Tests/MultipleLoopTests.cs

@@ -67,7 +67,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests
 
                 await writeRequest.WriteAsync(
                     serverConnectionPipe,
-                    new ReadOnlyBuffer<byte>(new byte[] { 1, 2, 3, 4 }));
+                    new ReadOnlySequence<byte>(new byte[] { 1, 2, 3, 4 }));
 
                 writeRequest.Dispose();
                 serverConnectionPipe.Dispose();

test/Kestrel.Transport.Libuv.Tests/NetworkingTests.cs

@@ -161,7 +161,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests
                             {
                                 var req = new UvWriteReq(_logger);
                                 req.DangerousInit(loop);
-                                var block = new ReadOnlyBuffer<byte>(new byte[] { 65, 66, 67, 68, 69 });
+                                var block = new ReadOnlySequence<byte>(new byte[] { 65, 66, 67, 68, 69 });
 
                                 await req.WriteAsync(
                                     tcp2,

test/Kestrel.Transport.Libuv.Tests/TestHelpers/MockConnectionHandler.cs

@@ -13,8 +13,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests.TestHelpers
 {
     public class MockConnectionHandler : IConnectionHandler
     {
-        public Func<MemoryPool, PipeOptions> InputOptions { get; set; } = pool => new PipeOptions(pool);
+        public Func<MemoryPool<byte>, PipeOptions> InputOptions { get; set; } = pool => new PipeOptions(pool);
-        public Func<MemoryPool, PipeOptions> OutputOptions { get; set; } = pool => new PipeOptions(pool);
+        public Func<MemoryPool<byte>, PipeOptions> OutputOptions { get; set; } = pool => new PipeOptions(pool);
 
         public void OnConnection(IFeatureCollection features)
         {

tools/CodeGenerator/KnownHeaders.cs

@@ -523,7 +523,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return true;
         }}
         {(loop.ClassName == "HttpResponseHeaders" ? $@"
-        protected void CopyToFast(ref OutputWriter<PipeWriter> output)
+        internal void CopyToFast(ref BufferWriter<PipeWriter> output)
         {{
             var tempBits = _bits | (_contentLength.HasValue ? {1L << 63}L : 0);
             {Each(loop.Headers.Where(header => header.Identifier != "ContentLength").OrderBy(h => !h.PrimaryHeader), header => $@"