v4.0.0 (#1357)

Source/MQTTnet.AspNetCore.Tests/MQTTnet.AspNetCore.Tests.csproj

@@ -0,0 +1,35 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+        <IsPackable>false</IsPackable>
+        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
+        <EnableNETAnalyzers>false</EnableNETAnalyzers>
+        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.0" />
+        <PackageReference Include="MSTest.TestAdapter" Version="2.1.2" />
+        <PackageReference Include="MSTest.TestFramework" Version="2.1.2" />
+        <PackageReference Include="Microsoft.CodeAnalysis.Compilers" Version="4.0.1" />
+        <PackageReference Include="Microsoft.Net.Compilers" Version="4.0.1" />
+    </ItemGroup>
+
+    <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp3.1' ">
+        <PackageReference Include="Microsoft.AspNetCore.Hosting" Version="2.2.7" />
+        <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="2.2.0" />
+    </ItemGroup>
+
+    <ItemGroup Condition=" '$(TargetFramework)' != 'netcoreapp3.1' ">
+        <PackageReference Include="Microsoft.AspNetCore.Hosting" Version="2.1.1" />
+        <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="2.1.1" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
+        <ProjectReference Include="..\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj" />
+        <ProjectReference Include="..\MQTTnet.Tests\MQTTnet.Tests.csproj" />
+    </ItemGroup>
+
+</Project>

Source/MQTTnet.AspNetCore.Tests/Mockups/ConnectionContextMockup.cs

@@ -0,0 +1,26 @@
+// 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.Collections.Generic;
+using System.IO.Pipelines;
+using Microsoft.AspNetCore.Connections;
+using Microsoft.AspNetCore.Http.Features;
+
+namespace MQTTnet.AspNetCore.Tests.Mockups
+{
+    public class ConnectionContextMockup : ConnectionContext
+    {
+        public override string ConnectionId { get; set; }
+
+        public override IFeatureCollection Features { get; }
+
+        public override IDictionary<object, object> Items { get; set; }
+        public override IDuplexPipe Transport { get; set; }
+
+        public ConnectionContextMockup()
+        {
+            //Transport = new DefaultConnectionContext
+        }
+    }
+}

Source/MQTTnet.AspNetCore.Tests/Mockups/ConnectionHandlerMockup.cs

@@ -0,0 +1,50 @@
+// 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 Microsoft.AspNetCore.Connections;
+using MQTTnet.Adapter;
+using MQTTnet.Formatter;
+using MQTTnet.Server;
+using System;
+using System.Threading.Tasks;
+using MQTTnet.Diagnostics;
+
+namespace MQTTnet.AspNetCore.Tests.Mockups
+{
+    public class ConnectionHandlerMockup: IMqttServerAdapter
+    {
+        public TaskCompletionSource<MqttConnectionContext> Context { get; } = new TaskCompletionSource<MqttConnectionContext>();
+        public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
+
+        public async Task OnConnectedAsync(ConnectionContext connection)
+        {
+            try
+            {
+                var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535));
+                var context = new MqttConnectionContext(formatter, connection);
+                Context.TrySetResult(context);
+
+                await ClientHandler(context);
+            }
+            catch (Exception ex)
+            {
+                Context.TrySetException(ex);
+            }
+        }
+
+        public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
+        {
+            return Task.CompletedTask;
+        }
+
+        public Task StopAsync()
+        {
+            return Task.CompletedTask;
+        }
+
+        public void Dispose()
+        {
+        }
+    }
+}

Source/MQTTnet.AspNetCore.Tests/Mockups/DuplexPipeMockup.cs

@@ -0,0 +1,28 @@
+// 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.IO.Pipelines;
+
+namespace MQTTnet.AspNetCore.Tests.Mockups
+{
+    public class DuplexPipeMockup : IDuplexPipe
+    {
+        public DuplexPipeMockup()
+        {
+            var pool = new LimitedMemoryPool();
+            var pipeOptions = new PipeOptions(pool);
+            Receive = new Pipe(pipeOptions);
+            Send = new Pipe(pipeOptions);
+        }
+
+        PipeReader IDuplexPipe.Input => Receive.Reader;
+
+        PipeWriter IDuplexPipe.Output => Send.Writer;
+
+
+        public Pipe Receive { get; set; } 
+
+        public Pipe Send { get; set; }
+    }
+}

Source/MQTTnet.AspNetCore.Tests/Mockups/LimitedMemoryPool.cs

@@ -0,0 +1,22 @@
+// 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.Buffers;
+
+namespace MQTTnet.AspNetCore.Tests.Mockups
+{
+    public class LimitedMemoryPool : MemoryPool<byte>
+    {
+        protected override void Dispose(bool disposing)
+        {
+        }
+
+        public override IMemoryOwner<byte> Rent(int minBufferSize = -1)
+        {
+            return new MemoryOwner(minBufferSize);
+        }
+
+        public override int MaxBufferSize { get; }
+    }
+}

Source/MQTTnet.AspNetCore.Tests/Mockups/MemoryOwner.cs

@@ -0,0 +1,37 @@
+// 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;
+using System.Buffers;
+
+namespace MQTTnet.AspNetCore.Tests.Mockups
+{
+    public class MemoryOwner : IMemoryOwner<byte>
+    {
+        private readonly byte[] _raw;
+
+        public MemoryOwner(int size)
+        {
+            if (size <= 0)
+            {
+                size = 1024;
+            }
+
+            if (size > 4096)
+            {
+                size = 4096;
+            }
+
+            _raw = ArrayPool<byte>.Shared.Rent(size);
+            Memory = _raw;
+        }
+
+        public void Dispose()
+        {
+            ArrayPool<byte>.Shared.Return(_raw);
+        }
+
+        public Memory<byte> Memory { get; }
+    }
+}

Source/MQTTnet.AspNetCore.Tests/MqttConnectionContextTest.cs

@@ -0,0 +1,136 @@
+// 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 Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Connections;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+using System;
+using System.Net;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Adapter;
+using MQTTnet.AspNetCore.Tests.Mockups;
+using MQTTnet.Exceptions;
+using MQTTnet.Formatter;
+using MQTTnet.Packets;
+using MQTTnet.Client;
+using MQTTnet.Protocol;
+using MQTTnet.Tests.Extensions;
+
+namespace MQTTnet.AspNetCore.Tests
+{
+    [TestClass]
+    public class MqttConnectionContextTest
+    {
+        [TestMethod]
+        public async Task TestReceivePacketAsyncThrowsWhenReaderCompleted()
+        {
+            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
+            var pipe = new DuplexPipeMockup();
+            var connection = new DefaultConnectionContext();
+            connection.Transport = pipe;
+            var ctx = new MqttConnectionContext(serializer, connection);
+
+            pipe.Receive.Writer.Complete();
+
+            await Assert.ThrowsExceptionAsync<MqttCommunicationException>(() => ctx.ReceivePacketAsync(CancellationToken.None));
+        }
+
+        [TestMethod]
+        public async Task TestCorruptedConnectPacket()
+        {
+            var writer = new MqttBufferWriter(4096, 65535);
+            var serializer = new MqttPacketFormatterAdapter(writer);
+            var pipe = new DuplexPipeMockup();
+            var connection = new DefaultConnectionContext();
+            connection.Transport = pipe;
+            var ctx = new MqttConnectionContext(serializer, connection);
+            
+            await pipe.Receive.Writer.WriteAsync(writer.AddMqttHeader(MqttControlPacketType.Connect, new byte[0]));
+
+            await Assert.ThrowsExceptionAsync<MqttProtocolViolationException>(() => ctx.ReceivePacketAsync(CancellationToken.None));
+
+            // the first exception should complete the pipes so if someone tries to use the connection after that it should throw immidiatly
+            await Assert.ThrowsExceptionAsync<InvalidOperationException>(() =>  ctx.ReceivePacketAsync(CancellationToken.None));
+        }
+
+        // COMMENTED OUT DUE TO DEAD LOCK? OR VERY VERY SLOW PERFORMANCE ON LOCAL DEV MACHINE. TEST WAS STILL RUNNING AFTER SEVERAL MINUTES!
+        //[TestMethod]
+        //public async Task TestParallelWrites()
+        //{
+        //    var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311);
+        //    var pipe = new DuplexPipeMockup();
+        //    var connection = new DefaultConnectionContext();
+        //    connection.Transport = pipe;
+        //    var ctx = new MqttConnectionContext(serializer, connection);
+
+        //    var tasks = Enumerable.Range(1, 100).Select(_ => Task.Run(async () => 
+        //    {
+        //        for (int i = 0; i < 100; i++)
+        //        {
+        //            await ctx.SendPacketAsync(new MqttPublishPacket(), TimeSpan.Zero, CancellationToken.None).ConfigureAwait(false);
+        //        }
+        //    }));
+
+        //    await Task.WhenAll(tasks).ConfigureAwait(false);
+        //}
+        
+        [TestMethod]
+        public async Task TestLargePacket()
+        {
+            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
+            var pipe = new DuplexPipeMockup();
+            var connection = new DefaultConnectionContext();
+            connection.Transport = pipe;
+            var ctx = new MqttConnectionContext(serializer, connection);
+
+            await ctx.SendPacketAsync(new MqttPublishPacket { Payload = new byte[20_000] }, CancellationToken.None).ConfigureAwait(false);
+
+            var readResult = await pipe.Send.Reader.ReadAsync();
+            Assert.IsTrue(readResult.Buffer.Length > 20000);
+        }
+
+        private class Startup 
+        {
+            public void Configure(IApplicationBuilder app)
+            { 
+            }
+        }
+
+        [TestMethod]
+        public async Task TestEndpoint()
+        {
+            var mockup = new ConnectionHandlerMockup();
+
+
+            using (var host = new WebHostBuilder()
+                .UseKestrel(kestrel => kestrel.ListenLocalhost(1883, listener => listener.Use((ctx, next) => mockup.OnConnectedAsync(ctx))))
+                .UseStartup<Startup>()
+                .ConfigureServices((hostContext, services) =>
+                {
+                    services.AddHostedMqttServer(o => o.WithoutDefaultEndpoint());
+                    services.AddSingleton<IMqttServerAdapter>(mockup);
+                })
+                .Build())
+                
+            using (var client = new MqttFactory().CreateMqttClient())
+            {
+                host.Start();
+                await client.ConnectAsync(new MqttClientOptionsBuilder()
+                    .WithTcpServer("localhost")
+                    .Build(), CancellationToken.None);
+
+                var ctx = await mockup.Context.Task;
+#if NETCOREAPP3_1
+                var ep = IPEndPoint.Parse(ctx.Endpoint);
+                Assert.IsNotNull(ep);
+#endif
+                Assert.IsNotNull(ctx);
+            }               
+        }
+    }
+}

Source/MQTTnet.AspNetCore.Tests/ReaderExtensionsTest.cs

@@ -0,0 +1,51 @@
+// 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.
+
+#if NETCOREAPP3_1
+using System.Buffers;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.AspNetCore;
+using MQTTnet.Formatter;
+using MQTTnet.Packets;
+
+namespace MQTTnet.AspNetCore.Tests
+{
+    [TestClass]
+    public class ReaderExtensionsTest
+    {
+        [TestMethod]
+        public void TestTryDeserialize()
+        {
+            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
+
+            var buffer = serializer.Encode(new MqttPublishPacket {Topic = "a", Payload = new byte[5]}).Join();
+
+            var sequence = new ReadOnlySequence<byte>(buffer.Array, buffer.Offset, buffer.Count);
+
+            var part = sequence;
+            MqttPacket packet;
+            var consumed = part.Start;
+            var observed = part.Start;
+            var result = false;
+            var read = 0;
+            
+            part = sequence.Slice(sequence.Start, 0); // empty message should fail
+            result = serializer.TryDecode(part, out packet, out consumed, out observed, out read);
+            Assert.IsFalse(result);
+
+            part = sequence.Slice(sequence.Start, 1); // partial fixed header should fail
+            result = serializer.TryDecode(part, out packet, out consumed, out observed, out read);
+            Assert.IsFalse(result);
+
+            part = sequence.Slice(sequence.Start, 4); // partial body should fail
+            result = serializer.TryDecode(part, out packet, out consumed, out observed, out read);
+            Assert.IsFalse(result);
+
+            part = sequence; // complete msg should work
+            result = serializer.TryDecode(part, out packet, out consumed, out observed, out read);
+            Assert.IsTrue(result);
+        }
+    }
+}
+#endif

Source/MQTTnet.AspTestApp/MQTTnet.AspTestApp.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+    <PropertyGroup>
+        <TargetFramework>net6.0</TargetFramework>
+        <Nullable>enable</Nullable>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <IsPackable>false</IsPackable>
+        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
+        <EnableNETAnalyzers>false</EnableNETAnalyzers>
+        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\..\Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj"/>
+
+        <PackageReference Include="Microsoft.CodeAnalysis.Compilers" Version="4.0.1" />
+        <PackageReference Include="Microsoft.Net.Compilers" Version="4.0.1" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <Folder Include="wwwroot\"/>
+    </ItemGroup>
+
+</Project>

Source/MQTTnet.AspTestApp/Pages/Index.cshtml

@@ -0,0 +1,34 @@
+@page
+@model IndexModel
+@{
+    ViewData["Title"] = "Home page";
+}
+
+<div>
+    <h1>MQTTnet ASP.NET Core Test App</h1>
+</div>
+
+<script src="https://unpkg.com/mqtt/dist/mqtt.min.js"></script>
+
+<script>
+    const options = {
+      clean: true,
+      connectTimeout: 4000,
+      clientId: 'mqttnet_web_client'
+    }
+
+    const client  = mqtt.connect('ws://localhost:5049/mqtt')
+
+    client.on('connect', function () {
+      console.log('Connected')
+      client.subscribe('#', function (err) {
+        if (!err) {
+          client.publish('test', 'Hello mqtt')
+        }
+      })
+    })
+
+    client.on('message', function (topic, message) {
+      console.log(message.toString())
+    })
+</script>

Source/MQTTnet.AspTestApp/Pages/Index.cshtml.cs

@@ -0,0 +1,23 @@
+// 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 Microsoft.AspNetCore.Mvc.RazorPages;
+
+namespace MQTTnet.AspTestApp.Pages
+{
+    public class IndexModel : PageModel
+    {
+        private readonly ILogger<IndexModel> _logger;
+
+        public IndexModel(ILogger<IndexModel> logger)
+        {
+            _logger = logger;
+        }
+
+        public void OnGet()
+        {
+
+        }
+    }
+}

Source/MQTTnet.AspTestApp/Pages/Shared/_Layout.cshtml

@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>@ViewData["Title"] - MQTTnet</title>
+</head>
+<body>
+
+    @RenderBody()
+
+    @await RenderSectionAsync("Scripts", required: false)
+</body>
+</html>

Source/MQTTnet.AspTestApp/Pages/_ViewImports.cshtml

@@ -0,0 +1,2 @@
+@namespace MQTTnet.AspTestApp.Pages
+@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

Source/MQTTnet.AspTestApp/Pages/_ViewStart.cshtml

@@ -0,0 +1,3 @@
+@{
+    Layout = "_Layout";
+}

Source/MQTTnet.AspTestApp/Program.cs

@@ -0,0 +1,73 @@
+// 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 MQTTnet;
+using MQTTnet.AspNetCore;
+using MQTTnet.Server;
+
+var builder = WebApplication.CreateBuilder(args);
+
+builder.Services.AddRazorPages();
+
+// Setup MQTT stuff.
+builder.Services.AddMqttServer();
+builder.Services.AddConnections();
+
+var app = builder.Build();
+
+if (!app.Environment.IsDevelopment())
+{
+    app.UseExceptionHandler("/Error");
+}
+
+app.UseStaticFiles();
+
+app.UseRouting();
+
+app.UseAuthorization();
+
+app.MapRazorPages();
+
+// Setup MQTT stuff.
+app.UseEndpoints(endpoints =>
+{
+    endpoints.MapMqtt("/mqtt");
+});
+
+app.UseMqttServer(server =>
+{
+    server.StartedAsync += args =>
+    {
+        _ = Task.Run(async () =>
+        {
+            var mqttApplicationMessage = new MqttApplicationMessageBuilder()
+                .WithPayload($"Test application message from MQTTnet server.")
+                .WithTopic("message")
+                .Build();
+
+            while (true)
+            {
+                try
+                {
+                    await server.InjectApplicationMessage(new InjectedMqttApplicationMessage(mqttApplicationMessage)
+                    {
+                        SenderClientId = "server"
+                    });
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine(e);
+                }
+                finally
+                {
+                    await Task.Delay(TimeSpan.FromSeconds(5));
+                }
+            }
+        });
+
+        return Task.CompletedTask;
+    };
+});
+
+app.Run();

Source/MQTTnet.AspTestApp/appsettings.Development.json

@@ -0,0 +1,9 @@
+{
+  "DetailedErrors": true,
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

Source/MQTTnet.AspTestApp/appsettings.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}

Source/MQTTnet.AspTestApp/libman.json

@@ -0,0 +1,5 @@
+{
+  "version": "1.0",
+  "defaultProvider": "cdnjs",
+  "libraries": []
+}

Source/MQTTnet.AspnetCore/ApplicationBuilderExtensions.cs

@@ -1,9 +1,13 @@
-using System;
+// 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;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
 using MQTTnet.Server;
 
-namespace MQTTnet.AspNetCore.Extensions
+namespace MQTTnet.AspNetCore
 {
     public static class ApplicationBuilderExtensions
     {
@@ -36,9 +40,9 @@ namespace MQTTnet.AspNetCore.Extensions
             return app;
         }
 
-        public static IApplicationBuilder UseMqttServer(this IApplicationBuilder app, Action<IMqttServer> configure)
+        public static IApplicationBuilder UseMqttServer(this IApplicationBuilder app, Action<MqttServer> configure)
         {
-            var server = app.ApplicationServices.GetRequiredService<IMqttServer>();
+            var server = app.ApplicationServices.GetRequiredService<MqttServer>();
 
             configure(server);
 

Source/MQTTnet.AspnetCore/AspNetMqttServerOptionsBuilder.cs

@@ -1,13 +1,17 @@
-using MQTTnet.Server;
+// 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 MQTTnet.Server;
 using System;
 
 namespace MQTTnet.AspNetCore
 {
-    public class AspNetMqttServerOptionsBuilder : MqttServerOptionsBuilder
+    public sealed class AspNetMqttServerOptionsBuilder : MqttServerOptionsBuilder
     {
         public AspNetMqttServerOptionsBuilder(IServiceProvider serviceProvider)
         {
-            ServiceProvider = serviceProvider;
+            ServiceProvider = serviceProvider ?? throw new ArgumentNullException(nameof(serviceProvider));
         }
 
         public IServiceProvider ServiceProvider { get; }

Source/MQTTnet.AspnetCore/Client/MqttClientConnectionContextFactory.cs

@@ -1,15 +1,20 @@
-using MQTTnet.Adapter;
+// 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 MQTTnet.Adapter;
 using MQTTnet.AspNetCore.Client.Tcp;
-using MQTTnet.Client.Options;
 using MQTTnet.Formatter;
 using System;
 using System.Net;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
 
 namespace MQTTnet.AspNetCore.Client
 {
-    public class MqttClientConnectionContextFactory : IMqttClientAdapterFactory
+    public sealed class MqttClientConnectionContextFactory : IMqttClientAdapterFactory
     {
-        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options)
+        public IMqttChannelAdapter CreateClientAdapter(MqttClientOptions options, MqttPacketInspector packetInspector, IMqttNetLogger logger)
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
 
@@ -19,9 +24,8 @@ namespace MQTTnet.AspNetCore.Client
                     {
                         var endpoint = new DnsEndPoint(tcpOptions.Server, tcpOptions.GetPort());
                         var tcpConnection = new TcpConnection(endpoint);
-
-                        var writer = new SpanBasedMqttPacketWriter();
-                        var formatter = new MqttPacketFormatterAdapter(options.ProtocolVersion, writer);
+                        
+                        var formatter = new MqttPacketFormatterAdapter(options.ProtocolVersion, new MqttBufferWriter(4096, 65535));
                         return new MqttConnectionContext(formatter, tcpConnection);
                     }
                 default:

Source/MQTTnet.AspnetCore/Client/Tcp/BufferExtensions.cs

@@ -1,4 +1,8 @@
-using System;
+// 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;
 using System.Runtime.InteropServices;
 
 namespace MQTTnet.AspNetCore.Client.Tcp

Source/MQTTnet.AspnetCore/Client/Tcp/DuplexPipe.cs

@@ -1,4 +1,8 @@
-using System.IO.Pipelines;
+// 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.IO.Pipelines;
 
 namespace MQTTnet.AspNetCore.Client.Tcp
 {

Source/MQTTnet.AspnetCore/Client/Tcp/SocketAwaitable.cs

@@ -1,4 +1,8 @@
-using System;
+// 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;
 using System.Diagnostics;
 using System.IO.Pipelines;
 using System.Net.Sockets;

Source/MQTTnet.AspnetCore/Client/Tcp/SocketReceiver.cs

@@ -1,4 +1,8 @@
-using System;
+// 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;
 using System.IO.Pipelines;
 using System.Net.Sockets;
 

Source/MQTTnet.AspnetCore/Client/Tcp/SocketSender.cs

@@ -1,4 +1,8 @@
-using System;
+// 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;
 using System.Buffers;
 using System.Collections.Generic;
 using System.Diagnostics;

Source/MQTTnet.AspnetCore/Client/Tcp/TcpConnection.cs

@@ -1,4 +1,8 @@
-using Microsoft.AspNetCore.Connections;
+// 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 Microsoft.AspNetCore.Connections;
 using Microsoft.AspNetCore.Http.Features;
 using MQTTnet.Exceptions;
 using System;
@@ -40,7 +44,7 @@ namespace MQTTnet.AspNetCore.Client.Tcp
             _sender = new SocketSender(_socket, PipeScheduler.ThreadPool);
             _receiver = new SocketReceiver(_socket, PipeScheduler.ThreadPool);
         }
-#if NETCOREAPP3_1 || NET5_0
+#if NETCOREAPP3_1 || NET5_0_OR_GREATER
         public override ValueTask DisposeAsync()
 #else
         public Task DisposeAsync()
@@ -53,7 +57,7 @@ namespace MQTTnet.AspNetCore.Client.Tcp
 
             _socket?.Dispose();
 
-#if NETCOREAPP3_1 || NET5_0
+#if NETCOREAPP3_1 || NET5_0_OR_GREATER
 
             return base.DisposeAsync();
         }

Source/MQTTnet.AspnetCore/ConnectionBuilderExtensions.cs

@@ -0,0 +1,16 @@
+// 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 Microsoft.AspNetCore.Connections;
+
+namespace MQTTnet.AspNetCore
+{
+    public static class ConnectionBuilderExtensions
+    {
+        public static IConnectionBuilder UseMqtt(this IConnectionBuilder builder)
+        {
+            return builder.UseConnectionHandler<MqttConnectionHandler>();
+        }
+    }
+}

Source/MQTTnet.AspnetCore/ConnectionRouteBuilderExtensions.cs

@@ -1,11 +1,15 @@
-using Microsoft.AspNetCore.Http;
+// 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 Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Connections;
 
 #if NETCOREAPP3_1
 using System;
 #endif
 
-namespace MQTTnet.AspNetCore.Extensions
+namespace MQTTnet.AspNetCore
 {
     public static class ConnectionRouteBuilderExtensions
     {

Source/MQTTnet.AspnetCore/EndpointRouterExtensions.cs

@@ -1,5 +1,9 @@
-
-#if NETCOREAPP3_1 || NET5_0
+// 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.
+
+
+#if NETCOREAPP3_1 || NET5_0_OR_GREATER
 
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Routing;

Source/MQTTnet.AspnetCore/Extensions/ConnectionBuilderExtensions.cs

@@ -1,12 +0,0 @@
-using Microsoft.AspNetCore.Connections;
-
-namespace MQTTnet.AspNetCore.Extensions
-{
-    public static class ConnectionBuilderExtensions
-    {
-        public static IConnectionBuilder UseMqtt(this IConnectionBuilder builder)
-        {
-            return builder.UseConnectionHandler<MqttConnectionHandler>();
-        }
-    }
-}

Source/MQTTnet.AspnetCore/MQTTnet.AspNetCore.csproj

@@ -1,36 +1,71 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;netcoreapp2.1;netcoreapp3.1;net5.0</TargetFrameworks>
-    <Product />
-    <Company />
-    <Authors />
-    <PackageId />
-    <LangVersion>7.2</LangVersion>
-    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <PublishRepositoryUrl>true</PublishRepositoryUrl>
-    <IncludeSymbols>true</IncludeSymbols>
-    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
-  </PropertyGroup>
+    <PropertyGroup>
+        <TargetFrameworks>netstandard2.0;netcoreapp2.1;netcoreapp3.1;net5.0;net6.0</TargetFrameworks>
 
-  <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
-  </ItemGroup>
+        <AssemblyName>MQTTnet.AspNetCore</AssemblyName>
+        <RootNamespace>MQTTnet.AspNetCore</RootNamespace>
+        <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
+        <Company>The contributors of MQTTnet</Company>
+        <Product>MQTTnet</Product>
+        <Description>MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker) and supports v3.1.0, v3.1.1 and v5.0.0 of the MQTT protocol.</Description>
+        <Authors>The contributors of MQTTnet</Authors>
+        <PackageId>MQTTnet.AspNetCore</PackageId>
+        <SignAssembly>false</SignAssembly>
+        <DelaySign>false</DelaySign>
+        <PublishRepositoryUrl>true</PublishRepositoryUrl>
+        <IncludeSymbols>true</IncludeSymbols>
+        <SymbolPackageFormat>snupkg</SymbolPackageFormat>
+        <Copyright>Christian Kratky 2016-2022</Copyright>
+        <PackageProjectUrl>https://github.com/dotnet/MQTTnet</PackageProjectUrl>
+        <RepositoryUrl>https://github.com/dotnet/MQTTnet.git</RepositoryUrl>
+        <RepositoryType>git</RepositoryType>
+        <PackageTags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</PackageTags>
+        <NeutralLanguage>en-US</NeutralLanguage>
+        <EnableNETAnalyzers>false</EnableNETAnalyzers>
+        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
+        <PackageIcon>nuget.png</PackageIcon>
+        <EmbedUntrackedSources>true</EmbedUntrackedSources>
+        <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
+        <PackageLicenseFile>LICENSE</PackageLicenseFile>
+        <PackageReleaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</PackageReleaseNotes>
+        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
+        
+        <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    </PropertyGroup>
 
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
-    <DefineConstants>RELEASE;NETSTANDARD2_0</DefineConstants>
-  </PropertyGroup>
+    <ItemGroup>
+        <None Include="..\..\Images\nuget.png">
+            <Pack>True</Pack>
+            <PackagePath>\</PackagePath>
+        </None>
+    </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1' or '$(TargetFramework)' == 'net5.0' ">
-    <FrameworkReference Include="Microsoft.AspNetCore.App" />
-  </ItemGroup>
-    
-  <ItemGroup Condition="'$(TargetFramework)' != 'netcoreapp3.1' and '$(TargetFramework)' != 'net5.0' ">
-    <PackageReference Include="Microsoft.AspNetCore.Http.Connections" Version="1.1.0" />
-  </ItemGroup>
+    <ItemGroup>
+        <None Include="..\..\LICENSE">
+            <Pack>True</Pack>
+            <PackagePath>\</PackagePath>
+        </None>
+    </ItemGroup>
 
-  <ItemGroup>
-    <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
-  </ItemGroup>
+    <ItemGroup>
+        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+    </ItemGroup>
+
+    <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
+        <DefineConstants>RELEASE;NETSTANDARD2_0</DefineConstants>
+    </PropertyGroup>
+
+    <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1' or '$(TargetFramework)' == 'net5.0' or '$(TargetFramework)' == 'net6.0' ">
+        <FrameworkReference Include="Microsoft.AspNetCore.App" />
+    </ItemGroup>
+
+    <ItemGroup Condition="'$(TargetFramework)' != 'netcoreapp3.1' and '$(TargetFramework)' != 'net5.0' and '$(TargetFramework)' != 'net6.0' ">
+        <PackageReference Include="Microsoft.AspNetCore.Http.Connections" Version="1.1.0" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
+    </ItemGroup>
 
 </Project>

Source/MQTTnet.AspnetCore/MqttConnectionContext.cs

@@ -1,4 +1,8 @@
-using Microsoft.AspNetCore.Connections;
+// 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 Microsoft.AspNetCore.Connections;
 using Microsoft.AspNetCore.Http.Connections.Features;
 using MQTTnet.Adapter;
 using MQTTnet.AspNetCore.Client.Tcp;
@@ -10,7 +14,6 @@ using System.IO.Pipelines;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.AspNetCore.Extensions;
 using MQTTnet.Internal;
 
 namespace MQTTnet.AspNetCore
@@ -18,7 +21,6 @@ namespace MQTTnet.AspNetCore
     public sealed class MqttConnectionContext : IMqttChannelAdapter
     {
         readonly AsyncLock _writerLock = new AsyncLock();
-        readonly SpanBasedMqttPacketBodyReader _reader;
         
         PipeReader _input;
         PipeWriter _output;
@@ -33,8 +35,6 @@ namespace MQTTnet.AspNetCore
                 _input = Connection.Transport.Input;
                 _output = Connection.Transport.Output;
             }
-
-            _reader = new SpanBasedMqttPacketBodyReader();
         }
 
         public string Endpoint
@@ -73,7 +73,7 @@ namespace MQTTnet.AspNetCore
 
         IHttpContextFeature Http => Connection.Features.Get<IHttpContextFeature>();
 
-        public async Task ConnectAsync(TimeSpan timeout, CancellationToken cancellationToken)
+        public async Task ConnectAsync(CancellationToken cancellationToken)
         {
             if (Connection is TcpConnection tcp && !tcp.IsConnected)
             {
@@ -84,7 +84,7 @@ namespace MQTTnet.AspNetCore
             _output = Connection.Transport.Output;
         }
 
-        public Task DisconnectAsync(TimeSpan timeout, CancellationToken cancellationToken)
+        public Task DisconnectAsync(CancellationToken cancellationToken)
         {
             _input?.Complete();
             _output?.Complete();
@@ -92,7 +92,7 @@ namespace MQTTnet.AspNetCore
             return Task.CompletedTask;
         }
 
-        public async Task<MqttBasePacket> ReceivePacketAsync(CancellationToken cancellationToken)
+        public async Task<MqttPacket> ReceivePacketAsync(CancellationToken cancellationToken)
         {
             var input = Connection.Transport.Input;
 
@@ -120,7 +120,7 @@ namespace MQTTnet.AspNetCore
                     {
                         if (!buffer.IsEmpty)
                         {
-                            if (PacketFormatterAdapter.TryDecode(_reader, buffer, out var packet, out consumed, out observed, out var received))
+                            if (PacketFormatterAdapter.TryDecode(buffer, out var packet, out consumed, out observed, out var received))
                             {
                                 BytesReceived += received;
                                 return packet;
@@ -167,13 +167,14 @@ namespace MQTTnet.AspNetCore
             BytesSent = 0;
         }
 
-        public async Task SendPacketAsync(MqttBasePacket packet, CancellationToken cancellationToken)
+        public async Task SendPacketAsync(MqttPacket packet, CancellationToken cancellationToken)
         {
             var formatter = PacketFormatterAdapter;
+            
             using (await _writerLock.WaitAsync(cancellationToken).ConfigureAwait(false))
             {
                 var buffer = formatter.Encode(packet);
-                var msg = buffer.AsMemory();
+                var msg = buffer.Join().AsMemory();
                 var output = _output;
                 var result = await output.WriteAsync(msg, cancellationToken).ConfigureAwait(false);
                 if (result.IsCompleted)
@@ -181,7 +182,7 @@ namespace MQTTnet.AspNetCore
                     BytesSent += msg.Length;
                 }
 
-                PacketFormatterAdapter.FreeBuffer();
+                PacketFormatterAdapter.Cleanup();
             }
         }
 

Source/MQTTnet.AspnetCore/MqttConnectionHandler.cs

@@ -1,15 +1,22 @@
-using Microsoft.AspNetCore.Connections;
+// 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 Microsoft.AspNetCore.Connections;
 using Microsoft.AspNetCore.Connections.Features;
 using MQTTnet.Adapter;
 using MQTTnet.Server;
 using System;
 using System.Threading.Tasks;
+using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 
 namespace MQTTnet.AspNetCore
 {
-    public class MqttConnectionHandler : ConnectionHandler, IMqttServerAdapter
+    public sealed class MqttConnectionHandler : ConnectionHandler, IMqttServerAdapter
     {
+        MqttServerOptions _serverOptions;
+        
         public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
 
         public override async Task OnConnectedAsync(ConnectionContext connection)
@@ -20,9 +27,8 @@ namespace MQTTnet.AspNetCore
             {
                 transferFormatFeature.ActiveFormat = TransferFormat.Binary;
             }
-
-            var writer = new SpanBasedMqttPacketWriter();
-            var formatter = new MqttPacketFormatterAdapter(writer);
+            
+            var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(_serverOptions.WriterBufferSize, _serverOptions.WriterBufferSizeMax));
             using (var adapter = new MqttConnectionContext(formatter, connection))
             {
                 var clientHandler = ClientHandler;
@@ -33,8 +39,10 @@ namespace MQTTnet.AspNetCore
             }
         }
 
-        public Task StartAsync(IMqttServerOptions options)
+        public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
         {
+            _serverOptions = options;
+
             return Task.CompletedTask;
         }
 

Source/MQTTnet.AspnetCore/MqttHostedServer.cs

@@ -1,27 +1,27 @@
-using System;
+// 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.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Hosting;
 using MQTTnet.Adapter;
-using MQTTnet.Diagnostics.Logger;
+using MQTTnet.Diagnostics;
 using MQTTnet.Server;
 
 namespace MQTTnet.AspNetCore
 {
     public sealed class MqttHostedServer : MqttServer, IHostedService
     {
-        readonly IMqttServerOptions _options;
-
-        public MqttHostedServer(IMqttServerOptions options, IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger) 
-            : base(adapters, logger)
+        public MqttHostedServer(MqttServerOptions options, IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger) 
+            : base(options, adapters, logger)
         {
-            _options = options ?? throw new ArgumentNullException(nameof(options));
         }
 
         public Task StartAsync(CancellationToken cancellationToken)
         {
-            _ = StartAsync(_options);
+            _ =  StartAsync();
             return Task.CompletedTask;
         }
 
@@ -30,4 +30,4 @@ namespace MQTTnet.AspNetCore
             return StopAsync();
         }
     }
-}
+}

Source/MQTTnet.AspnetCore/MqttSubProtocolSelector.cs

@@ -1,4 +1,8 @@
-using System;
+// 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;
 using System.Collections.Generic;
 using System.Linq;
 using Microsoft.AspNetCore.Http;

Source/MQTTnet.AspnetCore/MqttWebSocketServerAdapter.cs

@@ -1,4 +1,8 @@
-using Microsoft.AspNetCore.Http;
+// 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 Microsoft.AspNetCore.Http;
 using MQTTnet.Adapter;
 using MQTTnet.Formatter;
 using MQTTnet.Implementations;
@@ -6,23 +10,19 @@ using MQTTnet.Server;
 using System;
 using System.Net.WebSockets;
 using System.Threading.Tasks;
-using MQTTnet.Diagnostics.Logger;
+using MQTTnet.Diagnostics;
 
 namespace MQTTnet.AspNetCore
 {
     public sealed class MqttWebSocketServerAdapter : IMqttServerAdapter
     {
-        readonly IMqttNetLogger _rootLogger;
-
-        public MqttWebSocketServerAdapter(IMqttNetLogger logger)
-        {
-            _rootLogger = logger ?? throw new ArgumentNullException(nameof(logger));
-        }
-
+        IMqttNetLogger _logger = new MqttNetNullLogger();
+        
         public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
 
-        public Task StartAsync(IMqttServerOptions options)
+        public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
         {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
             return Task.CompletedTask;
         }
 
@@ -45,11 +45,10 @@ namespace MQTTnet.AspNetCore
                 var clientHandler = ClientHandler;
                 if (clientHandler != null)
                 {
-                    var writer = new SpanBasedMqttPacketWriter();
-                    var formatter = new MqttPacketFormatterAdapter(writer);
+                    var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535));
                     var channel = new MqttWebSocketChannel(webSocket, endpoint, isSecureConnection, clientCertificate);
 
-                    using (var channelAdapter = new MqttChannelAdapter(channel, formatter, null, _rootLogger))
+                    using (var channelAdapter = new MqttChannelAdapter(channel, formatter, null, _logger))
                     {
                         await clientHandler(channelAdapter).ConfigureAwait(false);
                     }

Source/MQTTnet.AspnetCore/ReaderExtensions.cs

@@ -1,18 +1,21 @@
-using System;
+// 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;
 using System.Buffers;
 using MQTTnet.Adapter;
 using MQTTnet.Exceptions;
 using MQTTnet.Formatter;
 using MQTTnet.Packets;
 
-namespace MQTTnet.AspNetCore.Extensions
+namespace MQTTnet.AspNetCore
 {
     public static class ReaderExtensions
     {
         public static bool TryDecode(this MqttPacketFormatterAdapter formatter, 
-            SpanBasedMqttPacketBodyReader reader, 
             in ReadOnlySequence<byte> input, 
-            out MqttBasePacket packet, 
+            out MqttPacket packet, 
             out SequencePosition consumed, 
             out SequencePosition observed,
             out int bytesRead)
@@ -30,7 +33,7 @@ namespace MQTTnet.AspNetCore.Extensions
                 return false;
             }
 
-            var fixedheader = copy.First.Span[0];
+            var fixedHeader = copy.First.Span[0];
             if (!TryReadBodyLength(ref copy, out int headerLength, out var bodyLength))
             {
                 return false;
@@ -42,10 +45,9 @@ namespace MQTTnet.AspNetCore.Extensions
             }
 
             var bodySlice = copy.Slice(0, bodyLength);
-            var buffer = bodySlice.GetMemory();
-            reader.SetBuffer(buffer);
-
-            var receivedMqttPacket = new ReceivedMqttPacket(fixedheader, reader, buffer.Length + 2);
+            var buffer = bodySlice.GetMemory().ToArray();
+            
+            var receivedMqttPacket = new ReceivedMqttPacket(fixedHeader, new ArraySegment<byte>(buffer, 0, buffer.Length), buffer.Length + 2);
 
             if (formatter.ProtocolVersion == MqttProtocolVersion.Unknown)
             {
@@ -59,7 +61,7 @@ namespace MQTTnet.AspNetCore.Extensions
             return true;
         }
 
-        private static ReadOnlyMemory<byte> GetMemory(this in ReadOnlySequence<byte> input)
+        static ReadOnlyMemory<byte> GetMemory(this in ReadOnlySequence<byte> input)
         {
             if (input.IsSingleSegment)
             {
@@ -70,7 +72,7 @@ namespace MQTTnet.AspNetCore.Extensions
             return input.ToArray();
         }
 
-        private static bool TryReadBodyLength(ref ReadOnlySequence<byte> input, out int headerLength, out int bodyLength)
+        static bool TryReadBodyLength(ref ReadOnlySequence<byte> input, out int headerLength, out int bodyLength)
         {
             // Alorithm taken from https://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html.
             var multiplier = 1;
@@ -88,6 +90,7 @@ namespace MQTTnet.AspNetCore.Extensions
                 {
                     return false;
                 }
+
                 encodedByte = temp[index];
                 index++;
 

Source/MQTTnet.AspnetCore/ServiceCollectionExtensions.cs

@@ -1,17 +1,33 @@
-using System;
+// 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;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using MQTTnet.Adapter;
 using MQTTnet.Diagnostics;
-using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Implementations;
 using MQTTnet.Server;
 
-namespace MQTTnet.AspNetCore.Extensions
+namespace MQTTnet.AspNetCore
 {
     public static class ServiceCollectionExtensions
     {
-        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, IMqttServerOptions options)
+        public static IServiceCollection AddMqttServer(this IServiceCollection serviceCollection, Action<MqttServerOptionsBuilder> configure = null)
+        {
+            if (serviceCollection is null)
+            {
+                throw new ArgumentNullException(nameof(serviceCollection));
+            }
+
+            serviceCollection.AddMqttConnectionHandler();
+            serviceCollection.AddHostedMqttServer(configure);
+            
+            return serviceCollection;
+        }
+
+        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, MqttServerOptions options)
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
 
@@ -22,13 +38,13 @@ namespace MQTTnet.AspNetCore.Extensions
             return services;
         }
 
-        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, Action<MqttServerOptionsBuilder> configure)
+        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, Action<MqttServerOptionsBuilder> configure = null)
         {
-            services.AddSingleton<IMqttServerOptions>(s =>
+            services.AddSingleton<MqttServerOptions>(s =>
             {
-                var builder = new MqttServerOptionsBuilder();
-                configure(builder);
-                return builder.Build();
+                var serverOptionsBuilder = new MqttServerOptionsBuilder();
+                configure?.Invoke(serverOptionsBuilder);
+                return serverOptionsBuilder.Build();
             });
 
             services.AddHostedMqttServer();
@@ -38,7 +54,7 @@ namespace MQTTnet.AspNetCore.Extensions
 
         public static IServiceCollection AddHostedMqttServerWithServices(this IServiceCollection services, Action<AspNetMqttServerOptionsBuilder> configure)
         {
-            services.AddSingleton<IMqttServerOptions>(s =>
+            services.AddSingleton<MqttServerOptions>(s =>
             {
                 var builder = new AspNetMqttServerOptionsBuilder(s);
                 configure(builder);
@@ -50,24 +66,14 @@ namespace MQTTnet.AspNetCore.Extensions
             return services;
         }
 
-        public static IServiceCollection AddHostedMqttServer<TOptions>(this IServiceCollection services)
-            where TOptions : class, IMqttServerOptions
-        {
-            services.AddSingleton<IMqttServerOptions, TOptions>();
-
-            services.AddHostedMqttServer();
-
-            return services;
-        }
-
-        private static IServiceCollection AddHostedMqttServer(this IServiceCollection services)
+        static IServiceCollection AddHostedMqttServer(this IServiceCollection services)
         {
             var logger = new MqttNetEventLogger();
 
             services.AddSingleton<IMqttNetLogger>(logger);
             services.AddSingleton<MqttHostedServer>();
             services.AddSingleton<IHostedService>(s => s.GetService<MqttHostedServer>());
-            services.AddSingleton<IMqttServer>(s => s.GetService<MqttHostedServer>());
+            services.AddSingleton<MqttServer>(s => s.GetService<MqttHostedServer>());
 
             return services;
         }

Source/MQTTnet.AspnetCore/SpanBasedMqttPacketBodyReader.cs

@@ -1,129 +0,0 @@
-using MQTTnet.Exceptions;
-using MQTTnet.Formatter;
-using System;
-using System.Buffers.Binary;
-using System.Text;
-
-namespace MQTTnet.AspNetCore
-{
-    public class SpanBasedMqttPacketBodyReader : IMqttPacketBodyReader
-    {
-        ReadOnlyMemory<byte> _buffer;
-
-        int _offset;
-        
-        public void SetBuffer(ReadOnlyMemory<byte> buffer)
-        {
-            _buffer = buffer;
-            _offset = 0;
-        }
-
-        public int Length => _buffer.Length;
-
-        public bool EndOfStream => _buffer.Length.Equals(_offset);
-        
-        public int Offset => _offset;
-
-        public byte ReadByte()
-        {
-            return _buffer.Span[_offset++];
-        }
-
-        public byte[] ReadRemainingData()
-        {
-            return _buffer.Slice(_offset).ToArray();
-        }
-
-        public byte[] ReadWithLengthPrefix()
-        {
-            return ReadSegmentWithLengthPrefix().ToArray();
-        }
-        
-        public unsafe string ReadStringWithLengthPrefix()
-        {
-            var buffer = ReadSegmentWithLengthPrefix();
-            if (buffer.Length == 0)
-            {
-                return string.Empty;
-            }
-
-            fixed (byte* bytes = &buffer.GetPinnableReference())
-            {
-                var result = Encoding.UTF8.GetString(bytes, buffer.Length);
-                return result;
-            }
-        }
-
-        public ushort ReadTwoByteInteger()
-        {
-            var result = BinaryPrimitives.ReadUInt16BigEndian(_buffer.Span.Slice(_offset));
-            _offset += 2;
-            return result;
-        }
-
-        public uint ReadFourByteInteger()
-        {
-            var result = BinaryPrimitives.ReadUInt32BigEndian(_buffer.Span.Slice(_offset));
-            _offset += 4;
-            return result;
-        }
-
-        public uint ReadVariableLengthInteger()
-        {
-            var multiplier = 1;
-            var value = 0U;
-            byte encodedByte;
-
-            do
-            {
-                encodedByte = ReadByte();
-                value += (uint)((encodedByte & 127) * multiplier);
-
-                if (multiplier > 2097152)
-                {
-                    throw new MqttProtocolViolationException("Variable length integer is invalid.");
-                }
-
-                multiplier *= 128;
-            } while ((encodedByte & 128) != 0);
-
-            return value;
-        }
-
-        public bool ReadBoolean()
-        {
-            var buffer = ReadByte();
-
-            if (buffer == 0)
-            {
-                return false;
-            }
-
-            if (buffer == 1)
-            {
-                return true;
-            }
-
-            throw new MqttProtocolViolationException("Boolean values can be 0 or 1 only.");
-        }
-
-        public void Seek(int position)
-        {
-            _offset = position;
-        }
-
-        ReadOnlySpan<byte> ReadSegmentWithLengthPrefix()
-        {
-            var span = _buffer.Span;
-            var length = BinaryPrimitives.ReadUInt16BigEndian(span.Slice(_offset));
-
-            if (Length < _offset + length)
-            {
-                throw new MqttProtocolViolationException($"Expected at least {_offset + 2 + length} bytes but there are only {Length} bytes");
-            }
-            var result = span.Slice(_offset + 2, length);
-            _offset += 2 + length;
-            return result;
-        }
-    }
-}

Source/MQTTnet.AspnetCore/SpanBasedMqttPacketWriter.cs

@@ -1,144 +0,0 @@
-using MQTTnet.Formatter;
-using System;
-using System.Buffers;
-using System.Buffers.Binary;
-using System.Text;
-
-namespace MQTTnet.AspNetCore
-{
-    public class SpanBasedMqttPacketWriter : IMqttPacketWriter
-    {
-        readonly ArrayPool<byte> _pool = ArrayPool<byte>.Create();
-
-        public SpanBasedMqttPacketWriter()
-        {
-            Reset(0);
-        }
-
-        byte[] _buffer;
-        int _position;
-
-        public int Length { get; set; }
-
-        public void FreeBuffer()
-        {
-            _pool.Return(_buffer);
-        }
-
-        public byte[] GetBuffer()
-        {
-            return _buffer;
-        }
-
-        public void Reset(int v)
-        {
-            _buffer = _pool.Rent(1500);
-            Length = v;
-            _position = v;
-        }
-
-        public void Seek(int v)
-        {
-            _position = v;
-        }
-
-        public void Write(byte value)
-        {
-            GrowIfNeeded(1);
-            _buffer[_position] = value;
-            Commit(1);
-        }
-
-        public void Write(ushort value)
-        {
-            GrowIfNeeded(2);
-
-            BinaryPrimitives.WriteUInt16BigEndian(_buffer.AsSpan(_position), value);
-            Commit(2);
-        }
-
-        public void Write(IMqttPacketWriter propertyWriter)
-        {
-            if (propertyWriter == null) throw new ArgumentNullException(nameof(propertyWriter));
-
-            GrowIfNeeded(propertyWriter.Length);
-            Write(propertyWriter.GetBuffer(), 0, propertyWriter.Length);
-        }
-
-        public void Write(byte[] payload, int start, int length)
-        {
-            GrowIfNeeded(length);
-
-            payload.AsSpan(start, length).CopyTo(_buffer.AsSpan(_position));
-            Commit(length);
-        }
-
-        public void WriteVariableLengthInteger(uint value)
-        {
-            GrowIfNeeded(4);
-            
-            var x = value;
-            do
-            {
-                var encodedByte = x % 128;
-                x = x / 128;
-                if (x > 0)
-                {
-                    encodedByte = encodedByte | 128;
-                }
-
-                _buffer[_position] = (byte)encodedByte;
-                Commit(1);
-            } while (x > 0);
-        }
-
-        public void WriteWithLengthPrefix(string value)
-        {
-            var bytesLength = Encoding.UTF8.GetByteCount(value ?? string.Empty);
-            GrowIfNeeded(bytesLength + 2);
-
-            Write((ushort)bytesLength);
-            Encoding.UTF8.GetBytes(value ?? string.Empty, 0, value?.Length ?? 0, _buffer, _position);
-            Commit(bytesLength);
-        }
-
-        public void WriteWithLengthPrefix(byte[] payload)
-        {
-            GrowIfNeeded(payload.Length + 2);
-            
-            Write((ushort)payload.Length);
-            payload.CopyTo(_buffer, _position);
-            Commit(payload.Length);
-        }
-
-        void Commit(int count)
-        {
-            if (_position == Length)
-            {
-                Length += count;
-            }
-
-            _position += count;
-        }
-
-        void GrowIfNeeded(int requiredAdditional) 
-        {
-            var requiredTotal = _position + requiredAdditional;
-            if (_buffer.Length >= requiredTotal)
-            {
-                return;
-            }
-
-            var newBufferLength = _buffer.Length;
-            while (newBufferLength < requiredTotal)
-            {
-                newBufferLength *= 2;
-            }
-
-            var newBuffer = _pool.Rent(newBufferLength);
-            Array.Copy(_buffer, newBuffer, _buffer.Length);
-            _pool.Return(_buffer);
-            _buffer = newBuffer;
-        }
-    }
-}

Source/MQTTnet.Benchmarks/BaseBenchmark.cs

@@ -0,0 +1,6 @@
+namespace MQTTnet.Benchmarks
+{
+    public abstract class BaseBenchmark
+    {
+    }
+}

Source/MQTTnet.Benchmarks/ChannelAdapterBenchmark.cs

@@ -0,0 +1,90 @@
+// 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 BenchmarkDotNet.Attributes;
+using MQTTnet.Adapter;
+using MQTTnet.Internal;
+using MQTTnet.Packets;
+using System;
+using System.IO;
+using System.Threading;
+using MQTTnet.Diagnostics;
+using MQTTnet.Formatter;
+
+namespace MQTTnet.Benchmarks
+{
+    [MemoryDiagnoser]
+    public sealed class ChannelAdapterBenchmark
+    {
+        MqttChannelAdapter _channelAdapter;
+        int _iterations;
+        MemoryStream _stream;
+        MqttPublishPacket _packet;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            _packet = new MqttPublishPacket
+            {
+                Topic = "A"
+            };
+
+            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));
+            
+            var serializedPacket = Join(serializer.Encode(_packet).Join());
+
+            _iterations = 10000;
+
+            _stream = new MemoryStream(_iterations * serializedPacket.Length);
+
+            for (var i = 0; i < _iterations; i++)
+            {
+                _stream.Write(serializedPacket, 0, serializedPacket.Length);
+            }
+
+            _stream.Position = 0;
+
+            var channel = new TestMqttChannel(_stream);
+            
+            _channelAdapter = new MqttChannelAdapter(channel, serializer, null, new MqttNetEventLogger());
+        }
+
+        [Benchmark]
+        public void Receive_10000_Messages()
+        {
+            _stream.Position = 0;
+
+            for (var i = 0; i < 10000; i++)
+            {
+                _channelAdapter.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
+            }
+
+            _stream.Position = 0;
+        }
+
+        [Benchmark]
+        public void Send_10000_Messages()
+        {
+            _stream.Position = 0;
+
+            for (var i = 0; i < 10000; i++)
+            {
+                _channelAdapter.SendPacketAsync(_packet, CancellationToken.None).GetAwaiter().GetResult();
+            }
+
+            _stream.Position = 0;
+        }
+
+        static byte[] Join(params ArraySegment<byte>[] chunks)
+        {
+            var buffer = new MemoryStream();
+            foreach (var chunk in chunks)
+            {
+                buffer.Write(chunk.Array, chunk.Offset, chunk.Count);
+            }
+
+            return buffer.ToArray();
+        }
+    }
+}

Source/MQTTnet.Benchmarks/Configurations/AllowNonOptimized.cs

@@ -0,0 +1,22 @@
+// 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 BenchmarkDotNet.Jobs;
+using BenchmarkDotNet.Validators;
+
+namespace MQTTnet.Benchmarks.Configurations
+{
+    /// <summary>
+    /// this options may be used to run benchmarks in debugmode and attach a performance profiler
+    /// https://benchmarkdotnet.org/Configs/Configs.htm
+    /// </summary>
+    public class AllowNonOptimized : BaseConfig
+    {
+        public AllowNonOptimized()
+        {
+            AddValidator(JitOptimizationsValidator.DontFailOnError); // ALLOW NON-OPTIMIZED DLLS
+            AddJob(Job.InProcess);
+        }
+    }
+}

Source/MQTTnet.Benchmarks/Configurations/BaseConfig.cs

@@ -0,0 +1,19 @@
+// 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 BenchmarkDotNet.Configs;
+using System.Linq;
+
+namespace MQTTnet.Benchmarks.Configurations
+{
+    public class BaseConfig : ManualConfig
+    {
+        public BaseConfig()
+        {
+            AddLogger(DefaultConfig.Instance.GetLoggers().ToArray()); // manual config has no loggers by default
+            AddExporter(DefaultConfig.Instance.GetExporters().ToArray()); // manual config has no exporters by default
+            AddColumnProvider(DefaultConfig.Instance.GetColumnProviders().ToArray()); // manual config has no columns by default
+        }
+    }
+}

Source/MQTTnet.Benchmarks/Configurations/RuntimeCompareConfig.cs

@@ -0,0 +1,19 @@
+// 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 BenchmarkDotNet.Environments;
+using BenchmarkDotNet.Jobs;
+using BenchmarkDotNet.Toolchains.CsProj;
+
+namespace MQTTnet.Benchmarks.Configurations
+{
+    public class RuntimeCompareConfig : BaseConfig
+    {
+        public RuntimeCompareConfig()
+        {
+            AddJob(Job.Default.WithRuntime(ClrRuntime.Net48));
+            AddJob(Job.Default.WithRuntime(CoreRuntime.Core50).WithToolchain(CsProjCoreToolchain.NetCoreApp50));
+        }
+    }
+}

Source/MQTTnet.Benchmarks/LoggerBenchmark.cs

@@ -0,0 +1,91 @@
+// 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 BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Diagnostics;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [RPlotExporter]
+    [MemoryDiagnoser]
+    public class LoggerBenchmark
+    {
+        MqttNetNullLogger _nullLogger;
+        MqttNetSourceLogger _sourceNullLogger;
+        
+        MqttNetEventLogger _eventLogger;
+        MqttNetSourceLogger _sourceEventLogger;
+        
+        MqttNetEventLogger _eventLoggerNoListener;
+        MqttNetSourceLogger _sourceEventLoggerNoListener;
+        
+        bool _useHandler;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            _nullLogger = new MqttNetNullLogger();
+            _sourceNullLogger = _nullLogger.WithSource("Source");
+            
+            _eventLogger = new MqttNetEventLogger();
+            _eventLogger.LogMessagePublished += OnLogMessagePublished;
+            _sourceEventLogger = _eventLogger.WithSource("Source");
+            
+            _eventLoggerNoListener = new MqttNetEventLogger();
+            _sourceEventLoggerNoListener = _eventLoggerNoListener.WithSource("Source");
+        }
+
+        void OnLogMessagePublished(object sender, MqttNetLogMessagePublishedEventArgs eventArgs)
+        {
+            if (_useHandler)
+            {
+                eventArgs.LogMessage.ToString();
+            }
+        }
+
+        [Benchmark]
+        public void Log_10000_Messages_No_Listener()
+        {
+            _useHandler = false;
+            
+            for (var i = 0; i < 10000; i++)
+            {
+                _sourceEventLoggerNoListener.Verbose("test log message {0}", "parameter");
+            }
+        }
+
+        [Benchmark]
+        public void Log_10000_Messages_With_To_String()
+        {
+            _useHandler = true;
+            
+            for (var i = 0; i < 10000; i++)
+            {
+                _sourceEventLogger.Verbose("test log message {0}", "parameter");
+            }
+        }
+        
+        [Benchmark]
+        public void Log_10000_Messages_Without_To_String()
+        {
+            _useHandler = false;
+            
+            for (var i = 0; i < 10000; i++)
+            {
+                _sourceEventLogger.Verbose("test log message {0}", "parameter");
+            }
+        }
+        
+        [Benchmark]
+        public void Log_10000_Messages_With_NullLogger()
+        {
+            for (var i = 0; i < 10000; i++)
+            {
+                _sourceNullLogger.Verbose("test log message {0}", "parameter");
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/MQTTnet.Benchmarks.csproj

@@ -0,0 +1,39 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <DebugType>Full</DebugType>
+        <TargetFrameworks>net5.0;net6.0</TargetFrameworks>
+        <LangVersion>7.2</LangVersion>
+        <IsPackable>false</IsPackable>
+        <EnableNETAnalyzers>false</EnableNETAnalyzers>
+        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
+        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="BenchmarkDotNet" Version="0.12.1" />
+        <PackageReference Include="Microsoft.AspNetCore" Version="2.2.0" />
+    </ItemGroup>
+
+    <ItemGroup Condition="'$(TargetFramework)' != 'net5.0'">
+        <PackageReference Include="System.IO.Pipelines" Version="4.7.2" />
+    </ItemGroup>
+
+    <ItemGroup Condition="'$(TargetFramework)' == 'net5.0'">
+        <PackageReference Include="System.IO.Pipelines" Version="5.0.0" />
+    </ItemGroup>
+
+    <ItemGroup Condition="'$(TargetFramework)' == 'net6.0'">
+        <PackageReference Include="System.IO.Pipelines" Version="5.0.0" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\..\Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj" />
+
+        <PackageReference Include="Microsoft.CodeAnalysis.Compilers" Version="4.0.1" />
+        <PackageReference Include="Microsoft.Net.Compilers" Version="4.0.1" />
+        <ProjectReference Include="..\MQTTnet.Tests\MQTTnet.Tests.csproj" />
+    </ItemGroup>
+
+</Project>

Source/MQTTnet.Benchmarks/MessageDeliveryBenchmark.cs

@@ -0,0 +1,234 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Client;
+using MQTTnet.Server;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+
+namespace MQTTnet.Benchmarks
+{
+    /// <summary>
+    /// Create a number of topics, publish, subscribe, and wait for response
+    /// </summary>
+    [MemoryDiagnoser]
+    public class MessageDeliveryBenchmark
+    {
+        List<MqttApplicationMessage> _topicPublishMessages;
+
+        [Params(1, 5)]
+        public int NumTopicsPerPublisher;
+
+        [Params(1000, 10000)]
+        public int NumPublishers;
+
+        [Params(10)]
+        public int NumSubscribers;
+
+        [Params(5, 10, 20, 50)]
+        public int NumSubscribedTopicsPerSubscriber;
+
+        object _lockMsgCount;
+        int _messagesReceivedCount;
+        int _messagesExpectedCount;
+        CancellationTokenSource _cancellationTokenSource;
+
+        MqttServer _mqttServer;
+        List<MQTTnet.Client.MqttClient> _mqttSubscriberClients;
+        Dictionary<string, MQTTnet.Client.MqttClient> _mqttPublisherClientsByPublisherName;
+
+        Dictionary<string, List<string>> _topicsByPublisher;
+        Dictionary<string, string> _publisherByTopic;        
+        List<string> _allSubscribedTopics; // Keep track of the subset of topics that are subscribed
+
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            _lockMsgCount = new object();
+
+            Dictionary<string, List<string>> singleWildcardTopicsByPublisher;
+            Dictionary<string, List<string>> multiWildcardTopicsByPublisher;
+
+            TopicGenerator.Generate(NumPublishers, NumTopicsPerPublisher, out _topicsByPublisher, out singleWildcardTopicsByPublisher, out multiWildcardTopicsByPublisher);
+
+            var topics = _topicsByPublisher.First().Value;
+            _topicPublishMessages = new List<MqttApplicationMessage>();
+            // Prepare messages, same for each publisher
+            foreach (var topic in topics)
+            {
+                var message = new MqttApplicationMessageBuilder()
+                    .WithTopic(topic)
+                    .WithPayload(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 })
+                    .Build();
+                _topicPublishMessages.Add(message);
+            }
+
+            // Create server
+            var factory = new MqttFactory();
+            var serverOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
+            _mqttServer = factory.CreateMqttServer(serverOptions);
+            _mqttServer.StartAsync().GetAwaiter().GetResult();
+
+            // Create publisher clients
+            _mqttPublisherClientsByPublisherName = new Dictionary<string, MQTTnet.Client.MqttClient>();
+            foreach (var pt in _topicsByPublisher)
+            {
+                var publisherName = pt.Key;
+                var mqttClient = factory.CreateMqttClient();
+                var publisherOptions = new MqttClientOptionsBuilder()
+                    .WithTcpServer("localhost")
+                    .WithClientId(publisherName)
+                    .WithKeepAlivePeriod(TimeSpan.FromSeconds(30))
+                    .Build();
+                mqttClient.ConnectAsync(publisherOptions).GetAwaiter().GetResult();
+                _mqttPublisherClientsByPublisherName.Add(publisherName, mqttClient);
+            }
+
+            // Create subscriber clients
+            _mqttSubscriberClients = new List<MQTTnet.Client.MqttClient>();
+            for (var i = 0; i < NumSubscribers; i++)
+            {
+                var mqttSubscriberClient = factory.CreateMqttClient();
+                _mqttSubscriberClients.Add(mqttSubscriberClient);
+
+                var subscriberOptions = new MqttClientOptionsBuilder()
+                       .WithTcpServer("localhost")
+                       .WithClientId("subscriber" + i)
+                       .Build();
+                mqttSubscriberClient.ApplicationMessageReceivedAsync += r =>
+                {
+                    // count messages and signal cancellation when expected message count is reached
+                    lock (_lockMsgCount)
+                    {
+                        ++_messagesReceivedCount;
+                        if (_messagesReceivedCount == _messagesExpectedCount)
+                        {
+                            _cancellationTokenSource.Cancel();
+                        }
+                    }
+                    return Task.CompletedTask;
+                };
+                mqttSubscriberClient.ConnectAsync(subscriberOptions).GetAwaiter().GetResult();
+            }
+
+
+            List<string> allTopics = new List<string>();
+            _publisherByTopic = new Dictionary<string, string>();
+            foreach (var t in _topicsByPublisher)
+            {
+                foreach (var topic in t.Value)
+                {
+                    _publisherByTopic.Add(topic, t.Key);
+                    allTopics.Add(topic);
+                }
+            }
+
+            // Subscribe to NumSubscribedTopics topics spread across all topics
+            _allSubscribedTopics = new List<string>();
+
+            var totalNumTopics = NumPublishers * NumTopicsPerPublisher;
+            int topicIndexStep = totalNumTopics / (NumSubscribedTopicsPerSubscriber * NumSubscribers);
+            if (topicIndexStep * NumSubscribedTopicsPerSubscriber * NumSubscribers != totalNumTopics)
+            {
+                throw new System.Exception(
+                    String.Format("The total number of topics must be divisible by the number of subscribed topics across all subscribers. Total number of topics: {0}, topic step: {1}", 
+                    totalNumTopics, topicIndexStep
+                    ));
+            }
+
+            var topicIndex = 0;
+            foreach (var mqttSubscriber in _mqttSubscriberClients)
+            {
+                for (var i = 0; i < NumSubscribedTopicsPerSubscriber; ++i, topicIndex += topicIndexStep)
+                {
+                    var topic = allTopics[topicIndex];
+                    _allSubscribedTopics.Add(topic);
+                    var subOptions = new Client.MqttClientSubscribeOptionsBuilder().WithTopicFilter(
+                        new Packets.MqttTopicFilter() { Topic = topic })
+                        .Build();
+                    mqttSubscriber.SubscribeAsync(subOptions).GetAwaiter().GetResult();
+                }
+            }
+
+            Task.Delay(1000).GetAwaiter().GetResult();
+        }
+
+        /// <summary>
+        /// Publish messages and wait for messages sent to subscribers
+        /// </summary>
+        [Benchmark]
+        public void DeliverMessages()
+        {
+            // There should be one message received per publish for each subscribed topic
+            _messagesExpectedCount = NumSubscribedTopicsPerSubscriber * NumSubscribers;
+
+            // Loop for a while and exchange messages
+
+            _messagesReceivedCount = 0;
+
+            _cancellationTokenSource = new CancellationTokenSource();
+
+            // same payload for all messages
+            var payload = new byte[] { 1, 2, 3, 4 };
+
+            var tasks = new List<Task>();
+
+            // publish a message for each subscribed topic
+            foreach (var topic in _allSubscribedTopics)
+            {
+                var message = new MqttApplicationMessageBuilder()
+                    .WithTopic(topic)
+                    .WithPayload(payload)
+                    .Build();
+                // pick the correct publisher
+                var publisherName = _publisherByTopic[topic];
+                var publisherClient = _mqttPublisherClientsByPublisherName[publisherName];
+                _ = publisherClient.PublishAsync(message);
+            }
+      
+            // Wait one message per publish to be received by subscriber (in the subscriber's application message handler)
+            try
+            {
+                Task.Delay(30000, _cancellationTokenSource.Token).GetAwaiter().GetResult();
+            }
+            catch
+            {
+
+            }
+
+            _cancellationTokenSource.Dispose();
+
+            if (_messagesReceivedCount < _messagesExpectedCount)
+            {
+                throw new Exception(string.Format("Messages Received Count mismatch, expected {0}, received {1}", _messagesExpectedCount, _messagesReceivedCount));
+            }
+        }
+
+        [GlobalCleanup]
+        public void Cleanup()
+        {
+            foreach (var mp in _mqttPublisherClientsByPublisherName)
+            {
+                var mqttPublisherClient = mp.Value;
+                mqttPublisherClient.DisconnectAsync().GetAwaiter().GetResult();
+                mqttPublisherClient.Dispose();
+            }
+            _mqttPublisherClientsByPublisherName.Clear();
+
+            foreach (var mqttSubscriber in _mqttSubscriberClients)
+            {
+                mqttSubscriber.DisconnectAsync().GetAwaiter().GetResult();
+                mqttSubscriber.Dispose();
+            }
+            _mqttSubscriberClients.Clear();
+
+            _mqttServer.StopAsync().GetAwaiter().GetResult();
+            _mqttServer.Dispose();
+            _mqttServer = null;
+        }
+    }
+}

Source/MQTTnet.Benchmarks/MessageProcessingBenchmark.cs

@@ -0,0 +1,52 @@
+// 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 BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Client;
+using MQTTnet.Server;
+using MqttClient = MQTTnet.Client.MqttClient;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [RPlotExporter, RankColumn]
+    [MemoryDiagnoser]
+    public class MessageProcessingBenchmark
+    {
+        MqttServer _mqttServer;
+        MqttClient _mqttClient;
+        MqttApplicationMessage _message;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            var serverOptions = new MqttServerOptionsBuilder().Build();
+            
+            var factory = new MqttFactory();
+            _mqttServer = factory.CreateMqttServer(serverOptions);
+            _mqttClient = factory.CreateMqttClient();
+
+            _mqttServer.StartAsync().GetAwaiter().GetResult();
+
+            var clientOptions = new MqttClientOptionsBuilder()
+                .WithTcpServer("localhost").Build();
+
+            _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
+
+            _message = new MqttApplicationMessageBuilder()
+                .WithTopic("A")
+                .Build();
+        }
+
+        [Benchmark]
+        public void Send_10000_Messages()
+        {
+            for (var i = 0; i < 10000; i++)
+            {
+                _mqttClient.PublishAsync(_message).GetAwaiter().GetResult();
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/MessageProcessingMqttConnectionContextBenchmark.cs

@@ -0,0 +1,75 @@
+// 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 BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Client;
+using Microsoft.AspNetCore;
+using Microsoft.AspNetCore.Hosting;
+using MQTTnet.AspNetCore.Client;
+using MQTTnet.AspNetCore;
+using MQTTnet.Diagnostics;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [MemoryDiagnoser]
+    public class MessageProcessingMqttConnectionContextBenchmark
+    {
+        IWebHost _host;
+        MqttClient _mqttClient;
+        MqttApplicationMessage _message;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            _host = WebHost.CreateDefaultBuilder()
+                   .UseKestrel(o => o.ListenAnyIP(1883, l => l.UseMqtt()))
+                   .ConfigureServices(services => {
+                        services
+                            .AddHostedMqttServer(mqttServerOptions => mqttServerOptions.WithoutDefaultEndpoint())
+                            .AddMqttConnectionHandler();
+                   })
+                   .Configure(app => {
+                       app.UseMqttServer(s => {
+
+                       });
+                   })
+                   .Build();
+
+            var factory = new MqttFactory();
+            _mqttClient = factory.CreateMqttClient(new MqttNetEventLogger(), new MqttClientConnectionContextFactory());
+
+            _host.StartAsync().GetAwaiter().GetResult();
+
+            var clientOptions = new MqttClientOptionsBuilder()
+                .WithTcpServer("localhost").Build();
+
+            _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
+
+            _message = new MqttApplicationMessageBuilder()
+                .WithTopic("A")
+                .Build();
+        }
+
+        [GlobalCleanup]
+        public void Cleanup()
+        {
+            _mqttClient.DisconnectAsync().GetAwaiter().GetResult();
+            _mqttClient.Dispose();
+
+            _host.StopAsync().GetAwaiter().GetResult();
+            _host.Dispose();
+        }
+
+        [Benchmark]
+        public void Send_10000_Messages()
+        {
+            for (var i = 0; i < 10000; i++)
+            {
+                _mqttClient.PublishAsync(_message).GetAwaiter().GetResult();
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/MqttPacketReaderWriterBenchmark.cs

@@ -0,0 +1,93 @@
+using System;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.AspNetCore;
+using MQTTnet.Formatter;
+using MQTTnet.Tests.Mockups;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [MemoryDiagnoser]
+    public class MqttPacketReaderWriterBenchmark
+    {
+        readonly byte[] _demoPayload = new byte[1024];
+        
+        byte[] _readPayload;
+
+        [GlobalCleanup]
+        public void GlobalCleanup()
+        {
+        }
+
+        [GlobalSetup]
+        public void GlobalSetup()
+        {
+            TestEnvironment.EnableLogger = false;
+            
+            var writer = new MqttBufferWriter(4096, 65535);
+            writer.WriteString("A relative short string.");
+            writer.WriteBinaryData(_demoPayload);
+            writer.WriteByte(0x01);
+            writer.WriteByte(0x02);
+            writer.WriteVariableByteInteger(5647382);
+            writer.WriteString("A relative short string.");
+            writer.WriteVariableByteInteger(8574489);
+            writer.WriteBinaryData(_demoPayload);
+            writer.WriteByte(2);
+            writer.WriteByte(0x02);
+            writer.WriteString("fjgffiogfhgfhoihgoireghreghreguhreguireoghreouighreouighreughreguiorehreuiohruiorehreuioghreug");
+            writer.WriteBinaryData(_demoPayload);
+
+            _readPayload = new ArraySegment<byte>(writer.GetBuffer(), 0, writer.Length).ToArray();
+        }
+
+        [Benchmark]
+        public void Read_100_000_Messages()
+        {
+            var reader = new MqttBufferReader();
+            reader.SetBuffer(_readPayload, 0, _readPayload.Length);
+
+            for (var i = 0; i < 100000; i++)
+            {
+                reader.Seek(0);
+
+                reader.ReadString();
+                reader.ReadBinaryData();
+                reader.ReadByte();
+                reader.ReadByte();
+                reader.ReadVariableByteInteger();
+                reader.ReadString();
+                reader.ReadVariableByteInteger();
+                reader.ReadBinaryData();
+                reader.ReadByte();
+                reader.ReadByte();
+                reader.ReadString();
+                reader.ReadBinaryData();
+            }
+        }
+        
+        [Benchmark]
+        public void Write_100_000_Messages()
+        {
+            var writer = new MqttBufferWriter(4096, 65535);
+
+            for (var i = 0; i < 100000; i++)
+            {
+                writer.WriteString("A relative short string.");
+                writer.WriteByte(0x01);
+                writer.WriteByte(0x02);
+                writer.WriteVariableByteInteger(5647382);
+                writer.WriteString("A relative short string.");
+                writer.WriteVariableByteInteger(8574589);
+                writer.WriteBinaryData(_demoPayload);
+                writer.WriteByte(2);
+                writer.WriteByte(0x02);
+                writer.WriteString("fjgffiogfhgfhoihgoireghreghreguhreguireoghreouighreouighreughreguiorehreuiohruiorehreuioghreug");
+                writer.WriteBinaryData(_demoPayload);
+
+                writer.Reset(0);
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/MqttTcpChannelBenchmark.cs

@@ -0,0 +1,88 @@
+// 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 BenchmarkDotNet.Attributes;
+using MQTTnet.Channel;
+using MQTTnet.Implementations;
+using MQTTnet.Server;
+using System.Threading;
+using System.Threading.Tasks;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [MemoryDiagnoser]
+    public sealed class MqttTcpChannelBenchmark
+    {
+        MqttServer _mqttServer;
+        IMqttChannel _serverChannel;
+        IMqttChannel _clientChannel;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            var factory = new MqttFactory();
+            var tcpServer = new MqttTcpServerAdapter();
+            tcpServer.ClientHandler += args =>
+            {
+                _serverChannel =
+                    (IMqttChannel)args.GetType().GetField("_channel",
+                            System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)
+                        .GetValue(args);
+
+                return Task.CompletedTask;
+            };
+
+            var serverOptions = new MqttServerOptionsBuilder().Build();
+            _mqttServer = factory.CreateMqttServer(serverOptions, new[] { tcpServer }, new MqttNetEventLogger());
+
+            
+            _mqttServer.StartAsync().GetAwaiter().GetResult();
+
+            var clientOptions = new MqttClientOptionsBuilder()
+                .WithTcpServer("localhost").Build();
+
+            var tcpOptions = (MqttClientTcpOptions)clientOptions.ChannelOptions;
+            _clientChannel = new MqttTcpChannel(new MqttClientOptions { ChannelOptions = tcpOptions });
+
+            _clientChannel.ConnectAsync(CancellationToken.None).GetAwaiter().GetResult();
+        }
+
+        [Benchmark]
+        public async Task Send_10000_Chunks()
+        {
+            var size = 5;
+            var iterations = 10000;
+
+            await Task.WhenAll(WriteAsync(iterations, size), ReadAsync(iterations, size));
+        }
+
+        async Task ReadAsync(int iterations, int size)
+        {
+            await Task.Yield();
+
+            var expected = iterations * size;
+            long read = 0;
+
+            while (read < expected)
+            {
+                var readresult = await _clientChannel.ReadAsync(new byte[size], 0, size, CancellationToken.None).ConfigureAwait(false);
+                read += readresult;
+            }
+        }
+
+        async Task WriteAsync(int iterations, int size)
+        {
+            await Task.Yield();
+
+            for (var i = 0; i < iterations; i++)
+            {
+                await _serverChannel.WriteAsync(new byte[size], 0, size, CancellationToken.None).ConfigureAwait(false);
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/Program.cs

@@ -0,0 +1,83 @@
+// 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;
+using BenchmarkDotNet.Running;
+using MQTTnet.Benchmarks.Configurations;
+using MQTTnet.Diagnostics;
+
+namespace MQTTnet.Benchmarks
+{
+    public static class Program
+    {
+        public static void Main(string[] args)
+        {
+            Console.WriteLine($"MQTTnet - Benchmarks ({TargetFrameworkProvider.TargetFramework})");
+            Console.WriteLine("--------------------------------------------------------");
+            Console.WriteLine("1 = MessageProcessingBenchmark");
+            Console.WriteLine("2 = SerializerBenchmark");
+            Console.WriteLine("3 = LoggerBenchmark");
+            Console.WriteLine("4 = TopicFilterComparerBenchmark");
+            Console.WriteLine("5 = ChannelAdapterBenchmark");
+            Console.WriteLine("6 = MqttTcpChannelBenchmark");
+            Console.WriteLine("7 = TcpPipesBenchmark");
+            Console.WriteLine("8 = MessageProcessingMqttConnectionContextBenchmark");
+            Console.WriteLine("9 = ServerProcessingBenchmark");
+            Console.WriteLine("a = MqttPacketReaderWriterBenchmark");
+            Console.WriteLine("b = RoundtripBenchmark");
+            Console.WriteLine("c = SubscribeBenchmark");
+            Console.WriteLine("d = UnsubscribeBenchmark");
+            Console.WriteLine("e = MessageDeliveryBenchmark");
+
+            var pressedKey = Console.ReadKey(true);
+            switch (pressedKey.KeyChar)
+            {
+                case '1':
+                    BenchmarkRunner.Run<MessageProcessingBenchmark>();
+                    break;
+                case '2':
+                    BenchmarkRunner.Run<SerializerBenchmark>();
+                    break;
+                case '3':
+                    BenchmarkRunner.Run<LoggerBenchmark>();
+                    break;
+                case '4':
+                    BenchmarkRunner.Run<TopicFilterComparerBenchmark>();
+                    break;
+                case '5':
+                    BenchmarkRunner.Run<ChannelAdapterBenchmark>();
+                    break;
+                case '6':
+                    BenchmarkRunner.Run<MqttTcpChannelBenchmark>();
+                    break;
+                case '7':
+                    BenchmarkRunner.Run<TcpPipesBenchmark>();
+                    break;
+                case '8':
+                    BenchmarkRunner.Run<MessageProcessingMqttConnectionContextBenchmark>(new RuntimeCompareConfig());
+                    break;
+                case '9':
+                    BenchmarkRunner.Run<ServerProcessingBenchmark>();
+                    break;
+                case 'a':
+                    BenchmarkRunner.Run(typeof(MqttPacketReaderWriterBenchmark));
+                    break;
+                case 'b':
+                    BenchmarkRunner.Run<RoundtripProcessingBenchmark>();
+                    break;
+                case 'c':
+                    BenchmarkRunner.Run<SubscribeBenchmark>();
+                    break;
+                case 'd':
+                    BenchmarkRunner.Run<UnsubscribeBenchmark>();
+                    break;
+                case 'e':
+                    BenchmarkRunner.Run<MessageDeliveryBenchmark>();
+                    break;
+            }
+
+            Console.ReadLine();
+        }
+    }
+}

Source/MQTTnet.Benchmarks/RoundtripProcessingBenchmark.cs

@@ -0,0 +1,30 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Tests.Mockups;
+using MQTTnet.Tests.Server;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [RPlotExporter, RankColumn]
+    [MemoryDiagnoser]
+    public class RoundtripProcessingBenchmark
+    {
+        [GlobalSetup]
+        public void GlobalSetup()
+        {
+            TestEnvironment.EnableLogger = false;
+        }
+        
+        [GlobalCleanup]
+        public void GlobalCleanup()
+        {
+        }
+        
+        [Benchmark]
+        public void Handle_100_000_Messages_In_Receiving_Client()
+        {
+            new Load_Tests().Handle_100_000_Messages_In_Receiving_Client().GetAwaiter().GetResult();
+        }
+    }
+}

Source/MQTTnet.Benchmarks/SerializerBenchmark.cs

@@ -0,0 +1,117 @@
+// 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 BenchmarkDotNet.Attributes;
+using MQTTnet.Packets;
+using System;
+using System.Security.Cryptography.X509Certificates;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Adapter;
+using MQTTnet.Channel;
+using MQTTnet.Formatter;
+using MQTTnet.Formatter.V3;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Diagnostics;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [RPlotExporter]
+    [MemoryDiagnoser]
+    public class SerializerBenchmark : BaseBenchmark
+    {
+        MqttPacket _packet;
+        ArraySegment<byte> _serializedPacket;
+        IMqttPacketFormatter _serializer;
+        MqttBufferWriter _bufferWriter;
+
+        [GlobalSetup]
+        public void GlobalSetup()
+        {
+            _packet = new MqttPublishPacket
+            {
+                Topic = "A"
+            };
+
+            _bufferWriter = new MqttBufferWriter(4096, 65535);
+            _serializer = new MqttV3PacketFormatter(_bufferWriter, MqttProtocolVersion.V311);
+            _serializedPacket = _serializer.Encode(_packet).Join();
+        }
+
+        [Benchmark]
+        public void Serialize_10000_Messages()
+        {
+            for (var i = 0; i < 10000; i++)
+            {
+                _serializer.Encode(_packet);
+                _bufferWriter.Cleanup();
+            }
+        }
+
+        [Benchmark]
+        public void Deserialize_10000_Messages()
+        {
+            var channel = new BenchmarkMqttChannel(_serializedPacket);
+            var reader = new MqttChannelAdapter(channel, new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535)), null, new MqttNetEventLogger());
+
+            for (var i = 0; i < 10000; i++)
+            {
+                channel.Reset();
+
+                var header = reader.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
+            }
+        }
+
+        class BenchmarkMqttChannel : IMqttChannel
+        {
+            readonly ArraySegment<byte> _buffer;
+            int _position;
+
+            public BenchmarkMqttChannel(ArraySegment<byte> buffer)
+            {
+                _buffer = buffer;
+                _position = _buffer.Offset;
+            }
+
+            public string Endpoint { get; } = string.Empty;
+
+            public bool IsSecureConnection { get; } = false;
+
+            public X509Certificate2 ClientCertificate { get; }
+
+            public void Reset()
+            {
+                _position = _buffer.Offset;
+            }
+
+            public Task ConnectAsync(CancellationToken cancellationToken)
+            {
+                throw new NotSupportedException();
+            }
+
+            public Task DisconnectAsync(CancellationToken cancellationToken)
+            {
+                throw new NotSupportedException();
+            }
+
+            public Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+            {
+                Array.Copy(_buffer.Array, _position, buffer, offset, count);
+                _position += count;
+
+                return Task.FromResult(count);
+            }
+
+            public Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+            {
+                throw new NotSupportedException();
+            }
+
+            public void Dispose()
+            {
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/ServerProcessingBenchmark.cs

@@ -0,0 +1,36 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Tests.Mockups;
+using MQTTnet.Tests.Server;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [RPlotExporter, RankColumn]
+    [MemoryDiagnoser]
+    public class ServerProcessingBenchmark
+    {
+        [GlobalSetup]
+        public void GlobalSetup()
+        {
+            TestEnvironment.EnableLogger = false;
+        }
+        
+        [GlobalCleanup]
+        public void GlobalCleanup()
+        {
+        }
+        
+        [Benchmark]
+        public void Handle_100_000_Messages_In_Server_MqttClient()
+        {
+            new Load_Tests().Handle_100_000_Messages_In_Server().GetAwaiter().GetResult();
+        }
+        
+        //[Benchmark]
+        public void Handle_100_000_Messages_In_Server_LowLevelMqttClient()
+        {
+            new Load_Tests().Handle_100_000_Messages_In_Low_Level_Client().GetAwaiter().GetResult();
+        }
+    }
+}

Source/MQTTnet.Benchmarks/SubscribeBenchmark.cs

@@ -0,0 +1,61 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Client;
+using MQTTnet.Server;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace MQTTnet.Benchmarks
+{
+    [MemoryDiagnoser]
+    public class SubscribeBenchmark
+    {
+        MqttServer _mqttServer;
+        MQTTnet.Client.MqttClient _mqttClient;
+
+        const int NumPublishers = 1;
+        const int NumTopicsPerPublisher = 10000;
+
+        List<string> _topics;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            TopicGenerator.Generate(NumPublishers, NumTopicsPerPublisher, out var topicsByPublisher, out var singleWildcardTopicsByPublisher, out var multiWildcardTopicsByPublisher);
+            _topics = topicsByPublisher.Values.First();
+
+            var serverOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
+
+            var factory = new MqttFactory();
+            _mqttServer = factory.CreateMqttServer(serverOptions);
+            _mqttClient = factory.CreateMqttClient();
+
+            _mqttServer.StartAsync().GetAwaiter().GetResult();
+
+            var clientOptions = new MqttClientOptionsBuilder()
+                .WithTcpServer("localhost").Build();
+
+            _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
+        }
+
+        [GlobalCleanup]
+        public void Cleanup()
+        {
+            _mqttClient.DisconnectAsync().GetAwaiter().GetResult();
+            _mqttServer.StopAsync().GetAwaiter().GetResult();
+            _mqttServer.Dispose();
+        }
+
+        [Benchmark]
+        public void Subscribe_10000_Topics()
+        {
+            foreach (var topic in _topics)
+            {
+                var subscribeOptions = new MqttClientSubscribeOptionsBuilder()
+                       .WithTopicFilter(topic, Protocol.MqttQualityOfServiceLevel.AtMostOnce)
+                       .Build();
+                _mqttClient.SubscribeAsync(subscribeOptions).GetAwaiter().GetResult();
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/TcpPipesBenchmark.cs

@@ -0,0 +1,80 @@
+// 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.IO.Pipelines;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.AspNetCore.Client.Tcp;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [MemoryDiagnoser]
+    public class TcpPipesBenchmark
+    {
+        IDuplexPipe _client;
+        IDuplexPipe _server;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            var server = new TcpListener(IPAddress.Any, 1883);
+
+            server.Start(1);
+
+            var task = Task.Run(() => server.AcceptSocket());
+
+            var clientConnection = new TcpConnection(new IPEndPoint(IPAddress.Loopback, 1883));
+
+            clientConnection.StartAsync().GetAwaiter().GetResult();
+            _client = clientConnection.Transport;
+
+            var serverConnection = new TcpConnection(task.GetAwaiter().GetResult());
+            serverConnection.StartAsync().GetAwaiter().GetResult();
+            _server = serverConnection.Transport;
+        }
+
+
+        [Benchmark]
+        public async Task Send_10000_Chunks_Pipe()
+        {
+            var size = 5;
+            var iterations = 10000;
+
+            await Task.WhenAll(WriteAsync(iterations, size), ReadAsync(iterations, size));
+        }
+
+        async Task ReadAsync(int iterations, int size)
+        {
+            await Task.Yield();
+
+            var expected = iterations * size;
+            long read = 0;
+            var input = _client.Input;
+
+            while (read < expected)
+            {
+                var readresult = await input.ReadAsync(CancellationToken.None).ConfigureAwait(false);
+                input.AdvanceTo(readresult.Buffer.End);
+                read += readresult.Buffer.Length;
+            }
+        }
+
+        async Task WriteAsync(int iterations, int size)
+        {
+            await Task.Yield();
+
+            var output = _server.Output;
+
+            for (var i = 0; i < iterations; i++)
+            {
+                await output.WriteAsync(new byte[size], CancellationToken.None).ConfigureAwait(false);
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/TopicFilterComparerBenchmark.cs

@@ -0,0 +1,277 @@
+// 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;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+
+namespace MQTTnet.Benchmarks
+{
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    [RPlotExporter]
+    [MemoryDiagnoser]
+    public class TopicFilterComparerBenchmark
+    {
+        static readonly char[] TopicLevelSeparator = { '/' };
+
+        readonly string _longTopic =
+            "AAAAAAAAAAAAAssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssshhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC";
+
+        [Benchmark]
+        public void MqttTopicFilterComparer_10000_LoopMethod()
+        {
+            for (var i = 0; i < 100000; i++)
+            {
+                MqttTopicFilterComparer.Compare("sport/tennis/player1", "sport/#");
+                MqttTopicFilterComparer.Compare("sport/tennis/player1/ranking", "sport/#/ranking");
+                MqttTopicFilterComparer.Compare("sport/tennis/player1/score/wimbledon", "sport/+/player1/#");
+                MqttTopicFilterComparer.Compare("sport/tennis/player1", "sport/tennis/+");
+                MqttTopicFilterComparer.Compare("/finance", "+/+");
+                MqttTopicFilterComparer.Compare("/finance", "/+");
+                MqttTopicFilterComparer.Compare("/finance", "+");
+                MqttTopicFilterComparer.Compare(_longTopic, _longTopic);
+            }
+        }
+
+        [Benchmark]
+        public void MqttTopicFilterComparer_10000_LoopMethod_Without_Pointer()
+        {
+            for (var i = 0; i < 100000; i++)
+            {
+                MqttTopicFilterComparerWithoutPointer.Compare("sport/tennis/player1", "sport/#");
+                MqttTopicFilterComparerWithoutPointer.Compare("sport/tennis/player1/ranking", "sport/#/ranking");
+                MqttTopicFilterComparerWithoutPointer.Compare("sport/tennis/player1/score/wimbledon", "sport/+/player1/#");
+                MqttTopicFilterComparerWithoutPointer.Compare("sport/tennis/player1", "sport/tennis/+");
+                MqttTopicFilterComparerWithoutPointer.Compare("/finance", "+/+");
+                MqttTopicFilterComparerWithoutPointer.Compare("/finance", "/+");
+                MqttTopicFilterComparerWithoutPointer.Compare("/finance", "+");
+                MqttTopicFilterComparerWithoutPointer.Compare(_longTopic, _longTopic);
+            }
+        }
+
+        [Benchmark]
+        public void MqttTopicFilterComparer_10000_StringSplitMethod()
+        {
+            for (var i = 0; i < 100000; i++)
+            {
+                LegacyMethodByStringSplit("sport/tennis/player1", "sport/#");
+                LegacyMethodByStringSplit("sport/tennis/player1/ranking", "sport/#/ranking");
+                LegacyMethodByStringSplit("sport/tennis/player1/score/wimbledon", "sport/+/player1/#");
+                LegacyMethodByStringSplit("sport/tennis/player1", "sport/tennis/+");
+                LegacyMethodByStringSplit("/finance", "+/+");
+                LegacyMethodByStringSplit("/finance", "/+");
+                LegacyMethodByStringSplit("/finance", "+");
+                MqttTopicFilterComparer.Compare(_longTopic, _longTopic);
+            }
+        }
+
+        [GlobalSetup]
+        public void Setup()
+        {
+        }
+
+        static bool LegacyMethodByStringSplit(string topic, string filter)
+        {
+            if (topic == null)
+            {
+                throw new ArgumentNullException(nameof(topic));
+            }
+
+            if (filter == null)
+            {
+                throw new ArgumentNullException(nameof(filter));
+            }
+
+            if (string.Equals(topic, filter, StringComparison.Ordinal))
+            {
+                return true;
+            }
+
+            var fragmentsTopic = topic.Split(TopicLevelSeparator, StringSplitOptions.None);
+            var fragmentsFilter = filter.Split(TopicLevelSeparator, StringSplitOptions.None);
+
+            // # > In either case it MUST be the last character specified in the Topic Filter [MQTT-4.7.1-2].
+            for (var i = 0; i < fragmentsFilter.Length; i++)
+            {
+                if (fragmentsFilter[i] == "+")
+                {
+                    continue;
+                }
+
+                if (fragmentsFilter[i] == "#")
+                {
+                    return true;
+                }
+
+                if (i >= fragmentsTopic.Length)
+                {
+                    return false;
+                }
+
+                if (!string.Equals(fragmentsFilter[i], fragmentsTopic[i], StringComparison.Ordinal))
+                {
+                    return false;
+                }
+            }
+
+            return fragmentsTopic.Length == fragmentsFilter.Length;
+        }
+
+        public static class MqttTopicFilterComparerWithoutPointer
+        {
+            public const char LevelSeparator = '/';
+            public const char MultiLevelWildcard = '#';
+            public const char SingleLevelWildcard = '+';
+            public const char ReservedTopicPrefix = '$';
+
+            public static MqttTopicFilterCompareResult Compare(string topic, string filter)
+            {
+                if (string.IsNullOrEmpty(topic))
+                {
+                    return MqttTopicFilterCompareResult.TopicInvalid;
+                }
+
+                if (string.IsNullOrEmpty(filter))
+                {
+                    return MqttTopicFilterCompareResult.FilterInvalid;
+                }
+
+                var filterOffset = 0;
+                var filterLength = filter.Length;
+
+                var topicOffset = 0;
+                var topicLength = topic.Length;
+
+                var topicPointer = topic;
+                var filterPointer = filter;
+
+                var isMultiLevelFilter = filterPointer[filterLength - 1] == MultiLevelWildcard;
+                var isReservedTopic = topicPointer[0] == ReservedTopicPrefix;
+
+                if (isReservedTopic && filterLength == 1 && isMultiLevelFilter)
+                {
+                    // It is not allowed to receive i.e. '$foo/bar' with filter '#'.
+                    return MqttTopicFilterCompareResult.NoMatch;
+                }
+
+                if (isReservedTopic && filterPointer[0] == SingleLevelWildcard)
+                {
+                    // It is not allowed to receive i.e. '$SYS/monitor/Clients' with filter '+/monitor/Clients'.
+                    return MqttTopicFilterCompareResult.NoMatch;
+                }
+
+                if (filterLength == 1 && isMultiLevelFilter)
+                {
+                    // Filter '#' matches basically everything.
+                    return MqttTopicFilterCompareResult.IsMatch;
+                }
+
+                // Go through the filter char by char.
+                while (filterOffset < filterLength && topicOffset < topicLength)
+                {
+                    // Check if the current char is a multi level wildcard. The char is only allowed
+                    // at the very las position.
+                    if (filterPointer[filterOffset] == MultiLevelWildcard && filterOffset != filterLength - 1)
+                    {
+                        return MqttTopicFilterCompareResult.FilterInvalid;
+                    }
+
+                    if (filterPointer[filterOffset] == topicPointer[topicOffset])
+                    {
+                        if (topicOffset == topicLength - 1)
+                        {
+                            // Check for e.g. "foo" matching "foo/#"
+                            if (filterOffset == filterLength - 3 && filterPointer[filterOffset + 1] == LevelSeparator && isMultiLevelFilter)
+                            {
+                                return MqttTopicFilterCompareResult.IsMatch;
+                            }
+
+                            // Check for e.g. "foo/" matching "foo/#"
+                            if (filterOffset == filterLength - 2 && filterPointer[filterOffset] == LevelSeparator && isMultiLevelFilter)
+                            {
+                                return MqttTopicFilterCompareResult.IsMatch;
+                            }
+                        }
+
+                        filterOffset++;
+                        topicOffset++;
+
+                        // Check if the end was reached and i.e. "foo/bar" matches "foo/bar"
+                        if (filterOffset == filterLength && topicOffset == topicLength)
+                        {
+                            return MqttTopicFilterCompareResult.IsMatch;
+                        }
+
+                        var endOfTopic = topicOffset == topicLength;
+
+                        if (endOfTopic && filterOffset == filterLength - 1 && filterPointer[filterOffset] == SingleLevelWildcard)
+                        {
+                            if (filterOffset > 0 && filterPointer[filterOffset - 1] != LevelSeparator)
+                            {
+                                return MqttTopicFilterCompareResult.FilterInvalid;
+                            }
+
+                            return MqttTopicFilterCompareResult.IsMatch;
+                        }
+                    }
+                    else
+                    {
+                        if (filterPointer[filterOffset] == SingleLevelWildcard)
+                        {
+                            // Check for invalid "+foo" or "a/+foo" subscription
+                            if (filterOffset > 0 && filterPointer[filterOffset - 1] != LevelSeparator)
+                            {
+                                return MqttTopicFilterCompareResult.FilterInvalid;
+                            }
+
+                            // Check for bad "foo+" or "foo+/a" subscription
+                            if (filterOffset < filterLength - 1 && filterPointer[filterOffset + 1] != LevelSeparator)
+                            {
+                                return MqttTopicFilterCompareResult.FilterInvalid;
+                            }
+
+                            filterOffset++;
+                            while (topicOffset < topicLength && topicPointer[topicOffset] != LevelSeparator)
+                            {
+                                topicOffset++;
+                            }
+
+                            if (topicOffset == topicLength && filterOffset == filterLength)
+                            {
+                                return MqttTopicFilterCompareResult.IsMatch;
+                            }
+                        }
+                        else if (filterPointer[filterOffset] == MultiLevelWildcard)
+                        {
+                            if (filterOffset > 0 && filterPointer[filterOffset - 1] != LevelSeparator)
+                            {
+                                return MqttTopicFilterCompareResult.FilterInvalid;
+                            }
+
+                            if (filterOffset + 1 != filterLength)
+                            {
+                                return MqttTopicFilterCompareResult.FilterInvalid;
+                            }
+
+                            return MqttTopicFilterCompareResult.IsMatch;
+                        }
+                        else
+                        {
+                            // Check for e.g. "foo/bar" matching "foo/+/#".
+                            if (filterOffset > 0 && filterOffset + 2 == filterLength && topicOffset == topicLength && filterPointer[filterOffset - 1] == SingleLevelWildcard &&
+                                filterPointer[filterOffset] == LevelSeparator && isMultiLevelFilter)
+                            {
+                                return MqttTopicFilterCompareResult.IsMatch;
+                            }
+
+                            return MqttTopicFilterCompareResult.NoMatch;
+                        }
+                    }
+                }
+
+                return MqttTopicFilterCompareResult.NoMatch;
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/TopicGenerator.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace MQTTnet.Benchmarks
+{
+    public class TopicGenerator
+    {
+        public static void Generate(
+           int numPublishers, int numTopicsPerPublisher,
+           out Dictionary<string, List<string>> topicsByPublisher,
+           out Dictionary<string, List<string>> singleWildcardTopicsByPublisher,
+           out Dictionary<string, List<string>> multiWildcardTopicsByPublisher
+           )
+        {
+            topicsByPublisher = new Dictionary<string, List<string>>();
+            singleWildcardTopicsByPublisher = new Dictionary<string, List<string>>();
+            multiWildcardTopicsByPublisher = new Dictionary<string, List<string>>();
+
+            // Find some reasonable distribution across three topic levels
+            var topicsPerLevel = (int)Math.Pow(numTopicsPerPublisher, (1.0 / 3.0));
+            if (topicsPerLevel <= 0)
+            {
+                topicsPerLevel = 1;
+            }
+
+            int numLevel1Topics = topicsPerLevel;
+            int numLevel2Topics = topicsPerLevel;
+
+            var maxNumLevel3Topics = 1 + (int)((double)numTopicsPerPublisher / numLevel1Topics / numLevel2Topics);
+            if (maxNumLevel3Topics <= 0)
+            {
+                maxNumLevel3Topics = 1;
+            }
+
+            for (var p = 0; p < numPublishers; ++p)
+            {
+                int publisherTopicCount = 0;
+                var publisherName = "pub" + p;
+                for (var l1 = 0; l1 < numLevel1Topics; ++l1)
+                {
+                    for (var l2 = 0; l2 < numLevel2Topics; ++l2)
+                    {
+                        for (var l3 = 0; l3 < maxNumLevel3Topics; ++l3)
+                        {
+                            if (publisherTopicCount >= numTopicsPerPublisher)
+                                break;
+
+                            var topic = string.Format("{0}/building{1}/level{2}/sensor{3}", publisherName, l1 + 1, l2 + 1, l3 + 1);
+                            AddPublisherTopic(publisherName, topic, topicsByPublisher);
+
+                            if (l2 == 0)
+                            {
+                                var singleWildcardTopic = string.Format("{0}/building{1}/+/sensor{2}", publisherName, l1 + 1, l3 + 1);
+                                AddPublisherTopic(publisherName, singleWildcardTopic, singleWildcardTopicsByPublisher);
+                            }
+                            if ((l1 == 0) && (l3 == 0))
+                            {
+                                var multiWildcardTopic = string.Format("{0}/+/level{1}/+", publisherName, l2 + 1);
+                                AddPublisherTopic(publisherName, multiWildcardTopic, multiWildcardTopicsByPublisher);
+                            }
+
+                            ++publisherTopicCount;
+                        }
+                    }
+                }
+            }
+        }
+
+        static void AddPublisherTopic(string publisherName, string topic, Dictionary<string, List<string>> topicsByPublisher)
+        {
+            List<string> topicList;
+            if (!topicsByPublisher.TryGetValue(publisherName, out topicList))
+            {
+                topicList = new List<string>();
+                topicsByPublisher.Add(publisherName, topicList);
+            }
+            topicList.Add(topic);
+        }
+    }
+}

Source/MQTTnet.Benchmarks/UnsubscribeBenchmark.cs

@@ -0,0 +1,61 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using MQTTnet.Client;
+using MQTTnet.Server;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace MQTTnet.Benchmarks
+{
+    [MemoryDiagnoser]
+    public class UnsubscribeBenchmark
+    {
+        MqttServer _mqttServer;
+        MQTTnet.Client.MqttClient _mqttClient;
+
+        const int NumPublishers = 1;
+        const int NumTopicsPerPublisher = 10000;
+
+        List<string> _topics;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            TopicGenerator.Generate(NumPublishers, NumTopicsPerPublisher, out var topicsByPublisher, out var singleWildcardTopicsByPublisher, out var multiWildcardTopicsByPublisher);
+            _topics = topicsByPublisher.Values.First();
+
+            var serverOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().Build();
+
+            var factory = new MqttFactory();
+            _mqttServer = factory.CreateMqttServer(serverOptions);
+            _mqttClient = factory.CreateMqttClient();
+
+            _mqttServer.StartAsync().GetAwaiter().GetResult();
+
+            var clientOptions = new MqttClientOptionsBuilder()
+                .WithTcpServer("localhost").Build();
+
+            _mqttClient.ConnectAsync(clientOptions).GetAwaiter().GetResult();
+
+            foreach (var topic in _topics)
+            {
+                var subscribeOptions = new MqttClientSubscribeOptionsBuilder()
+                       .WithTopicFilter(topic, Protocol.MqttQualityOfServiceLevel.AtMostOnce)
+                       .Build();
+                _mqttClient.SubscribeAsync(subscribeOptions).GetAwaiter().GetResult();
+            }
+        }
+
+        [Benchmark]
+        public void Unsubscribe_10000_Topics()
+        {
+            foreach (var topic in _topics)
+            {
+                var unsubscribeOptions = new MqttClientUnsubscribeOptionsBuilder()
+                       .WithTopicFilter(topic)
+                       .Build();
+                _mqttClient.UnsubscribeAsync(unsubscribeOptions).GetAwaiter().GetResult();
+            }
+        }
+    }
+}

Source/MQTTnet.Benchmarks/packages.config

@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="BenchmarkDotNet" version="0.10.14" targetFramework="net462" />
+  <package id="BenchmarkDotNet.Core" version="0.10.14" targetFramework="net462" />
+  <package id="BenchmarkDotNet.Toolchains.Roslyn" version="0.10.14" targetFramework="net462" />
+  <package id="Microsoft.CodeAnalysis.Analyzers" version="1.1.0" targetFramework="net462" />
+  <package id="Microsoft.CodeAnalysis.Common" version="2.6.1" targetFramework="net462" />
+  <package id="Microsoft.CodeAnalysis.CSharp" version="2.6.1" targetFramework="net462" />
+  <package id="Microsoft.DotNet.InternalAbstractions" version="1.0.0" targetFramework="net462" />
+  <package id="Microsoft.DotNet.PlatformAbstractions" version="1.1.1" targetFramework="net462" />
+  <package id="Microsoft.Win32.Registry" version="4.3.0" targetFramework="net462" />
+  <package id="System.AppContext" version="4.3.0" targetFramework="net462" />
+  <package id="System.Collections" version="4.3.0" targetFramework="net462" />
+  <package id="System.Collections.Concurrent" version="4.3.0" targetFramework="net462" />
+  <package id="System.Collections.Immutable" version="1.3.1" targetFramework="net462" />
+  <package id="System.Console" version="4.3.0" targetFramework="net462" />
+  <package id="System.Diagnostics.Debug" version="4.3.0" targetFramework="net462" />
+  <package id="System.Diagnostics.FileVersionInfo" version="4.3.0" targetFramework="net462" />
+  <package id="System.Diagnostics.StackTrace" version="4.3.0" targetFramework="net462" />
+  <package id="System.Diagnostics.Tools" version="4.3.0" targetFramework="net462" />
+  <package id="System.Dynamic.Runtime" version="4.3.0" targetFramework="net462" />
+  <package id="System.Globalization" version="4.3.0" targetFramework="net462" />
+  <package id="System.IO.Compression" version="4.3.0" targetFramework="net462" />
+  <package id="System.IO.FileSystem" version="4.3.0" targetFramework="net462" />
+  <package id="System.IO.FileSystem.Primitives" version="4.3.0" targetFramework="net462" />
+  <package id="System.Linq" version="4.3.0" targetFramework="net462" />
+  <package id="System.Linq.Expressions" version="4.3.0" targetFramework="net462" />
+  <package id="System.Reflection" version="4.3.0" targetFramework="net462" />
+  <package id="System.Reflection.Metadata" version="1.4.2" targetFramework="net462" />
+  <package id="System.Resources.ResourceManager" version="4.3.0" targetFramework="net462" />
+  <package id="System.Runtime" version="4.3.0" targetFramework="net462" />
+  <package id="System.Runtime.Extensions" version="4.3.0" targetFramework="net462" />
+  <package id="System.Runtime.InteropServices" version="4.3.0" targetFramework="net462" />
+  <package id="System.Runtime.Numerics" version="4.3.0" targetFramework="net462" />
+  <package id="System.Security.Cryptography.Algorithms" version="4.3.0" targetFramework="net462" />
+  <package id="System.Security.Cryptography.Encoding" version="4.3.0" targetFramework="net462" />
+  <package id="System.Security.Cryptography.Primitives" version="4.3.0" targetFramework="net462" />
+  <package id="System.Security.Cryptography.X509Certificates" version="4.3.0" targetFramework="net462" />
+  <package id="System.Text.Encoding" version="4.3.0" targetFramework="net462" />
+  <package id="System.Text.Encoding.CodePages" version="4.3.0" targetFramework="net462" />
+  <package id="System.Text.Encoding.Extensions" version="4.3.0" targetFramework="net462" />
+  <package id="System.Threading" version="4.3.0" targetFramework="net462" />
+  <package id="System.Threading.Tasks" version="4.3.0" targetFramework="net462" />
+  <package id="System.Threading.Tasks.Extensions" version="4.3.0" targetFramework="net462" />
+  <package id="System.Threading.Tasks.Parallel" version="4.3.0" targetFramework="net462" />
+  <package id="System.Threading.Thread" version="4.3.0" targetFramework="net462" />
+  <package id="System.ValueTuple" version="4.3.0" targetFramework="net462" />
+  <package id="System.Xml.ReaderWriter" version="4.3.0" targetFramework="net462" />
+  <package id="System.Xml.XDocument" version="4.3.0" targetFramework="net462" />
+  <package id="System.Xml.XmlDocument" version="4.3.0" targetFramework="net462" />
+  <package id="System.Xml.XmlSerializer" version="4.3.0" targetFramework="net462" />
+  <package id="System.Xml.XPath" version="4.3.0" targetFramework="net462" />
+  <package id="System.Xml.XPath.XDocument" version="4.3.0" targetFramework="net462" />
+</packages>

Source/MQTTnet.Extensions.ManagedClient/ApplicationMessageProcessedEventArgs.cs

@@ -1,8 +1,12 @@
-using System;
+// 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 MQTTnet.Extensions.ManagedClient
 {
-    public class ApplicationMessageProcessedEventArgs : EventArgs
+    public sealed class ApplicationMessageProcessedEventArgs : EventArgs
     {
         public ApplicationMessageProcessedEventArgs(ManagedMqttApplicationMessage applicationMessage, Exception exception)
         {
@@ -11,9 +15,10 @@ namespace MQTTnet.Extensions.ManagedClient
         }
 
         public ManagedMqttApplicationMessage ApplicationMessage { get; }
+        
+        /// <summary>
+        /// Then this is _null_ the message was processed successfully without any error.
+        /// </summary>
         public Exception Exception { get; }
-
-        public bool HasFailed => Exception != null;
-        public bool HasSucceeded => Exception == null;
     }
 }

Source/MQTTnet.Extensions.ManagedClient/ApplicationMessageProcessedHandlerDelegate.cs

@@ -1,31 +0,0 @@
-using System;
-using System.Threading.Tasks;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public class ApplicationMessageProcessedHandlerDelegate : IApplicationMessageProcessedHandler
-    {
-        private readonly Func<ApplicationMessageProcessedEventArgs, Task> _handler;
-
-        public ApplicationMessageProcessedHandlerDelegate(Action<ApplicationMessageProcessedEventArgs> handler)
-        {
-            if (handler == null) throw new ArgumentNullException(nameof(handler));
-
-            _handler = context =>
-            {
-                handler(context);
-                return Task.FromResult(0);
-            };
-        }
-
-        public ApplicationMessageProcessedHandlerDelegate(Func<ApplicationMessageProcessedEventArgs, Task> handler)
-        {
-            _handler = handler ?? throw new ArgumentNullException(nameof(handler));
-        }
-
-        public Task HandleApplicationMessageProcessedAsync(ApplicationMessageProcessedEventArgs eventArgs)
-        {
-            return _handler(eventArgs);
-        }
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/ApplicationMessageSkippedEventArgs.cs

@@ -1,4 +1,8 @@
-using System;
+// 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 MQTTnet.Extensions.ManagedClient
 {

Source/MQTTnet.Extensions.ManagedClient/ApplicationMessageSkippedHandlerDelegate.cs

@@ -1,4 +1,8 @@
-using System;
+// 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;
 using System.Threading.Tasks;
 
 namespace MQTTnet.Extensions.ManagedClient

Source/MQTTnet.Extensions.ManagedClient/ConnectingFailedEventArgs.cs

@@ -0,0 +1,21 @@
+using System;
+using MQTTnet.Client;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public sealed class ConnectingFailedEventArgs : EventArgs
+    {
+        public ConnectingFailedEventArgs(MqttClientConnectResult connectResult, Exception exception)
+        {
+            ConnectResult = connectResult;
+            Exception = exception;
+        }
+
+        /// <summary>
+        /// This is null when the connection was failing and the server was not reachable.
+        /// </summary>
+        public MqttClientConnectResult ConnectResult { get; }
+
+        public Exception Exception { get; }
+    }
+}

Source/MQTTnet.Extensions.ManagedClient/ConnectingFailedHandlerDelegate.cs

@@ -1,31 +0,0 @@
-using System;
-using System.Threading.Tasks;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public class ConnectingFailedHandlerDelegate : IConnectingFailedHandler
-    {
-        private readonly Func<ManagedProcessFailedEventArgs, Task> _handler;
-
-        public ConnectingFailedHandlerDelegate(Action<ManagedProcessFailedEventArgs> handler)
-        {
-            if (handler == null) throw new ArgumentNullException(nameof(handler));
-
-            _handler = eventArgs =>
-            {
-                handler(eventArgs);
-                return Task.FromResult(0);
-            };
-        }
-
-        public ConnectingFailedHandlerDelegate(Func<ManagedProcessFailedEventArgs, Task> handler)
-        {
-            _handler = handler ?? throw new ArgumentNullException(nameof(handler));
-        }
-
-        public Task HandleConnectingFailedAsync(ManagedProcessFailedEventArgs eventArgs)
-        {
-            return _handler(eventArgs);
-        }
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/IApplicationMessageProcessedHandler.cs

@@ -1,9 +0,0 @@
-using System.Threading.Tasks;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public interface IApplicationMessageProcessedHandler
-    {
-        Task HandleApplicationMessageProcessedAsync(ApplicationMessageProcessedEventArgs eventArgs);
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/IApplicationMessageSkippedHandler.cs

@@ -1,4 +1,8 @@
-using System.Threading.Tasks;
+// 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.Threading.Tasks;
 
 namespace MQTTnet.Extensions.ManagedClient
 {

Source/MQTTnet.Extensions.ManagedClient/IConnectingFailedHandler.cs

@@ -1,9 +0,0 @@
-using System.Threading.Tasks;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public interface IConnectingFailedHandler
-    {
-        Task HandleConnectingFailedAsync(ManagedProcessFailedEventArgs eventArgs);
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/IManagedMqttClient.cs

@@ -1,51 +0,0 @@
-using MQTTnet.Client.Connecting;
-using MQTTnet.Client.Disconnecting;
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Client;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public interface IManagedMqttClient : IApplicationMessageReceiver, IApplicationMessagePublisher, IDisposable
-    {
-        /// <summary>
-        /// Gets the internally used MQTT client.
-        /// This property should be used with caution because manipulating the internal client might break the managed client.
-        /// </summary>
-        IMqttClient InternalClient { get; }
-
-        bool IsStarted { get; }
-        
-        bool IsConnected { get; }
-        
-        int PendingApplicationMessagesCount { get; }
-        
-        IManagedMqttClientOptions Options { get; }
-        
-        IMqttClientConnectedHandler ConnectedHandler { get; set; }
-        
-        IMqttClientDisconnectedHandler DisconnectedHandler { get; set; }
-
-        IApplicationMessageProcessedHandler ApplicationMessageProcessedHandler { get; set; }
-        
-        IApplicationMessageSkippedHandler ApplicationMessageSkippedHandler { get; set; }
-
-        IConnectingFailedHandler ConnectingFailedHandler { get; set; }
-        
-        ISynchronizingSubscriptionsFailedHandler SynchronizingSubscriptionsFailedHandler { get; set; }
-
-        Task StartAsync(IManagedMqttClientOptions options);
-        
-        Task StopAsync();
-        
-        Task PingAsync(CancellationToken cancellationToken);
-
-        Task SubscribeAsync(IEnumerable<MqttTopicFilter> topicFilters);
-        
-        Task UnsubscribeAsync(IEnumerable<string> topics);
-
-        Task PublishAsync(ManagedMqttApplicationMessage applicationMessages);
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/IManagedMqttClientOptions.cs

@@ -1,27 +0,0 @@
-using System;
-using MQTTnet.Client.Options;
-using MQTTnet.Server;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public interface IManagedMqttClientOptions
-    {
-        IMqttClientOptions ClientOptions { get; }
-
-        TimeSpan AutoReconnectDelay { get; }
-
-        TimeSpan ConnectionCheckInterval { get; }
-
-        IManagedMqttClientStorage Storage { get; }
-
-        int MaxPendingMessages { get; }
-
-        MqttPendingMessagesOverflowStrategy PendingMessagesOverflowStrategy { get; }
-
-        /// <summary>
-        /// Defines the maximum amount of topic filters which will be sent in a SUBSCRIBE/UNSUBSCRIBE packet.
-        /// Amazon AWS limits this number to 8. The default is int.MaxValue.
-        /// </summary>
-        int MaxTopicFiltersInSubscribeUnsubscribePackets { get; }
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/IManagedMqttClientStorage.cs

@@ -1,4 +1,8 @@
-using System.Collections.Generic;
+// 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.Collections.Generic;
 using System.Threading.Tasks;
 
 namespace MQTTnet.Extensions.ManagedClient

Source/MQTTnet.Extensions.ManagedClient/ISynchronizingSubscriptionsFailedHandler.cs

@@ -1,4 +1,8 @@
-using System.Threading.Tasks;
+// 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.Threading.Tasks;
 
 namespace MQTTnet.Extensions.ManagedClient
 {

Source/MQTTnet.Extensions.ManagedClient/MQTTnet.Extensions.ManagedClient.csproj

@@ -1,40 +1,72 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
-    <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1;net5.0</TargetFrameworks>
-    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
-    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' AND '$(SolutionName)' != 'MQTTnet.noUWP' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
-    <Product />
-    <Company />
-    <Authors />
-    <PackageId />
-    <GeneratePackageOnBuild>False</GeneratePackageOnBuild>
-    <SignAssembly>false</SignAssembly>
-    <DelaySign>false</DelaySign>
-    <PublishRepositoryUrl>true</PublishRepositoryUrl>
-    <IncludeSymbols>true</IncludeSymbols>
-    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
-  </PropertyGroup>
+    <PropertyGroup>
+        <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1;netcoreapp3.1;net5.0;net6.0</TargetFrameworks>
+        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
+        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
+        
+        <AssemblyName>MQTTnet.Extensions.ManagedClient</AssemblyName>
+        <RootNamespace>MQTTnet.Extensions.ManagedClient</RootNamespace>
+        <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
+        <Company>The contributors of MQTTnet</Company>
+        <Product>MQTTnet</Product>
+        <Description>This is an extension library which provides a managed MQTT client with additional features using MQTTnet.</Description>
+        <Authors>The contributors of MQTTnet</Authors>
+        <PackageId>MQTTnet.Extensions.ManagedClient</PackageId>
+        <SignAssembly>false</SignAssembly>
+        <DelaySign>false</DelaySign>
+        <PublishRepositoryUrl>true</PublishRepositoryUrl>
+        <IncludeSymbols>true</IncludeSymbols>
+        <SymbolPackageFormat>snupkg</SymbolPackageFormat>
+        <Copyright>Christian Kratky 2016-2022</Copyright>
+        <PackageProjectUrl>https://github.com/dotnet/MQTTnet</PackageProjectUrl>
+        <RepositoryUrl>https://github.com/dotnet/MQTTnet.git</RepositoryUrl>
+        <RepositoryType>git</RepositoryType>
+        <PackageTags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</PackageTags>
+        <NeutralLanguage>en-US</NeutralLanguage>
+        <EnableNETAnalyzers>false</EnableNETAnalyzers>
+        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
+        <PackageIcon>nuget.png</PackageIcon>
+        <EmbedUntrackedSources>true</EmbedUntrackedSources>
+        <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
+        <PackageLicenseFile>LICENSE</PackageLicenseFile>
+        <PackageReleaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</PackageReleaseNotes>
+        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
+    </PropertyGroup>
 
-  <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
-    <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
-    <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
-    <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-    <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
-    <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
-    <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
-    <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
-    <DefineConstants>$(DefineConstants);WINDOWS_UWP</DefineConstants>
-    <DefaultLanguage>en</DefaultLanguage>
-    <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
-  </PropertyGroup>
+    <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
+        <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
+        <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
+        <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
+        <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
+        <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
+        <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
+        <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
+        <DefineConstants>$(DefineConstants);WINDOWS_UWP</DefineConstants>
+        <DefaultLanguage>en</DefaultLanguage>
+        <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
+    </PropertyGroup>
 
-  <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
-  </ItemGroup>
+    <ItemGroup>
+        <None Include="..\..\Images\nuget.png">
+            <Pack>True</Pack>
+            <PackagePath>\</PackagePath>
+        </None>
+    </ItemGroup>
 
-  <ItemGroup>
-    <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
-  </ItemGroup>
+    <ItemGroup>
+        <None Include="..\..\LICENSE">
+            <Pack>True</Pack>
+            <PackagePath>\</PackagePath>
+        </None>
+    </ItemGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
+    </ItemGroup>
 
 </Project>

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttApplicationMessage.cs

@@ -1,4 +1,8 @@
-using System;
+// 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 MQTTnet.Extensions.ManagedClient
 {

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttApplicationMessageBuilder.cs

@@ -1,4 +1,8 @@
-using System;
+// 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 MQTTnet.Extensions.ManagedClient
 {

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClient.cs

@@ -1,162 +1,155 @@
-using MQTTnet.Client;
-using MQTTnet.Client.Connecting;
-using MQTTnet.Client.Disconnecting;
-using MQTTnet.Client.Publishing;
-using MQTTnet.Client.Receiving;
-using MQTTnet.Diagnostics;
-using MQTTnet.Exceptions;
-using MQTTnet.Internal;
-using MQTTnet.Protocol;
-using MQTTnet.Server;
+// 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;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Diagnostics.Logger;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
+using MQTTnet.Exceptions;
+using MQTTnet.Internal;
+using MQTTnet.Packets;
+using MQTTnet.Protocol;
+using MQTTnet.Server;
+using MqttClient = MQTTnet.Client.MqttClient;
 
 namespace MQTTnet.Extensions.ManagedClient
 {
-    public class ManagedMqttClient : Disposable, IManagedMqttClient
+    public sealed class ManagedMqttClient : Disposable
     {
+        readonly AsyncEvent<ApplicationMessageProcessedEventArgs> _applicationMessageProcessedEvent = new AsyncEvent<ApplicationMessageProcessedEventArgs>();
+        readonly AsyncEvent<ConnectingFailedEventArgs> _connectingFailedEvent = new AsyncEvent<ConnectingFailedEventArgs>();
+        readonly AsyncEvent<EventArgs> _connectionStateChangedEvent = new AsyncEvent<EventArgs>();
+
+        readonly MqttNetSourceLogger _logger;
         readonly BlockingQueue<ManagedMqttApplicationMessage> _messageQueue = new BlockingQueue<ManagedMqttApplicationMessage>();
 
+        readonly AsyncLock _messageQueueLock = new AsyncLock();
+
         /// <summary>
-        /// The subscriptions are managed in 2 separate buckets:
-        /// <see cref="_subscriptions"/> and <see cref="_unsubscriptions"/> are processed during normal operation
-        /// and are moved to the <see cref="_reconnectSubscriptions"/> when they get processed. They can be accessed by
-        /// any thread and are therefore mutex'ed. <see cref="_reconnectSubscriptions"/> get sent to the broker
-        ///  at reconnect and are solely owned by <see cref="MaintainConnectionAsync"/>.
+        ///     The subscriptions are managed in 2 separate buckets:
+        ///     <see
+        ///         cref="_subscriptions" />
+        ///     and
+        ///     <see
+        ///         cref="_unsubscriptions" />
+        ///     are processed during normal operation
+        ///     and are moved to the
+        ///     <see
+        ///         cref="_reconnectSubscriptions" />
+        ///     when they get processed. They can be accessed by
+        ///     any thread and are therefore mutex'ed.
+        ///     <see
+        ///         cref="_reconnectSubscriptions" />
+        ///     get sent to the broker
+        ///     at reconnect and are solely owned by
+        ///     <see
+        ///         cref="MaintainConnectionAsync" />
+        ///     .
         /// </summary>
         readonly Dictionary<string, MqttQualityOfServiceLevel> _reconnectSubscriptions = new Dictionary<string, MqttQualityOfServiceLevel>();
 
         readonly Dictionary<string, MqttQualityOfServiceLevel> _subscriptions = new Dictionary<string, MqttQualityOfServiceLevel>();
-        readonly HashSet<string> _unsubscriptions = new HashSet<string>();
         readonly SemaphoreSlim _subscriptionsQueuedSignal = new SemaphoreSlim(0);
-
-        readonly MqttNetSourceLogger _logger;
-
-        readonly AsyncLock _messageQueueLock = new AsyncLock();
+        readonly HashSet<string> _unsubscriptions = new HashSet<string>();
 
         CancellationTokenSource _connectionCancellationToken;
-        CancellationTokenSource _publishingCancellationToken;
         Task _maintainConnectionTask;
+        CancellationTokenSource _publishingCancellationToken;
 
         ManagedMqttClientStorageManager _storageManager;
 
-        public ManagedMqttClient(IMqttClient mqttClient, IMqttNetLogger logger)
+        public ManagedMqttClient(MqttClient mqttClient, IMqttNetLogger logger)
         {
             InternalClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
 
-            if (logger == null) throw new ArgumentNullException(nameof(logger));
+            if (logger == null)
+            {
+                throw new ArgumentNullException(nameof(logger));
+            }
+
             _logger = logger.WithSource(nameof(ManagedMqttClient));
         }
 
+        public event Func<ApplicationMessageProcessedEventArgs, Task> ApplicationMessageProcessedAsync
+        {
+            add => _applicationMessageProcessedEvent.AddHandler(value);
+            remove => _applicationMessageProcessedEvent.RemoveHandler(value);
+        }
+
+        public event Func<MqttApplicationMessageReceivedEventArgs, Task> ApplicationMessageReceivedAsync
+        {
+            add => InternalClient.ApplicationMessageReceivedAsync += value;
+            remove => InternalClient.ApplicationMessageReceivedAsync -= value;
+        }
+
+        public event Func<EventArgs, Task> ConnectedAsync
+        {
+            add => InternalClient.ConnectedAsync += value;
+            remove => InternalClient.ConnectedAsync -= value;
+        }
+
+        public event Func<ConnectingFailedEventArgs, Task> ConnectingFailedAsync
+        {
+            add => _connectingFailedEvent.AddHandler(value);
+            remove => _connectingFailedEvent.RemoveHandler(value);
+        }
+
+        public event Func<EventArgs, Task> ConnectionStateChangedAsync
+        {
+            add => _connectionStateChangedEvent.AddHandler(value);
+            remove => _connectionStateChangedEvent.RemoveHandler(value);
+        }
+
+        public event Func<EventArgs, Task> DisconnectedAsync
+        {
+            add => InternalClient.DisconnectedAsync += value;
+            remove => InternalClient.DisconnectedAsync -= value;
+        }
+
+        public IApplicationMessageSkippedHandler ApplicationMessageSkippedHandler { get; set; }
+
+        public MqttClient InternalClient { get; }
+
         public bool IsConnected => InternalClient.IsConnected;
 
         public bool IsStarted => _connectionCancellationToken != null;
 
-        public IMqttClient InternalClient { get; }
+        public ManagedMqttClientOptions Options { get; private set; }
 
         public int PendingApplicationMessagesCount => _messageQueue.Count;
 
-        public IManagedMqttClientOptions Options { get; private set; }
-
-        public IMqttClientConnectedHandler ConnectedHandler
-        {
-            get => InternalClient.ConnectedHandler;
-            set => InternalClient.ConnectedHandler = value;
-        }
-
-        public IMqttClientDisconnectedHandler DisconnectedHandler
-        {
-            get => InternalClient.DisconnectedHandler;
-            set => InternalClient.DisconnectedHandler = value;
-        }
-
-        public IMqttApplicationMessageReceivedHandler ApplicationMessageReceivedHandler
-        {
-            get => InternalClient.ApplicationMessageReceivedHandler;
-            set => InternalClient.ApplicationMessageReceivedHandler = value;
-        }
-
-        public IApplicationMessageProcessedHandler ApplicationMessageProcessedHandler { get; set; }
-
-        public IApplicationMessageSkippedHandler ApplicationMessageSkippedHandler { get; set; }
-
-        public IConnectingFailedHandler ConnectingFailedHandler { get; set; }
-
         public ISynchronizingSubscriptionsFailedHandler SynchronizingSubscriptionsFailedHandler { get; set; }
 
-        public async Task StartAsync(IManagedMqttClientOptions options)
+        public async Task EnqueueAsync(MqttApplicationMessage applicationMessage)
         {
             ThrowIfDisposed();
 
-            if (options == null) throw new ArgumentNullException(nameof(options));
-            if (options.ClientOptions == null) throw new ArgumentException("The client options are not set.", nameof(options));
-
-            if (!_maintainConnectionTask?.IsCompleted ?? false) throw new InvalidOperationException("The managed client is already started.");
-
-            Options = options;
-
-            if (options.Storage != null)
+            if (applicationMessage == null)
             {
-                _storageManager = new ManagedMqttClientStorageManager(options.Storage);
-                var messages = await _storageManager.LoadQueuedMessagesAsync().ConfigureAwait(false);
-
-                foreach (var message in messages)
-                {
-                    _messageQueue.Enqueue(message);
-                }
+                throw new ArgumentNullException(nameof(applicationMessage));
             }
 
-            var cancellationTokenSource = new CancellationTokenSource();
-            var cancellationToken = cancellationTokenSource.Token;
-            _connectionCancellationToken = cancellationTokenSource;
-
-            _maintainConnectionTask = Task.Run(() => MaintainConnectionAsync(cancellationToken), cancellationToken);
-            _maintainConnectionTask.RunInBackground(_logger);
-
-            _logger.Info("Started");
+            var managedMqttApplicationMessage = new ManagedMqttApplicationMessageBuilder().WithApplicationMessage(applicationMessage);
+            await EnqueueAsync(managedMqttApplicationMessage.Build()).ConfigureAwait(false);
         }
 
-        public async Task StopAsync()
+        public async Task EnqueueAsync(ManagedMqttApplicationMessage applicationMessage)
         {
             ThrowIfDisposed();
 
-            StopPublishing();
-            StopMaintainingConnection();
-
-            _messageQueue.Clear();
-
-            if (_maintainConnectionTask != null)
+            if (applicationMessage == null)
             {
-                await Task.WhenAny(_maintainConnectionTask);
-                _maintainConnectionTask = null;
+                throw new ArgumentNullException(nameof(applicationMessage));
             }
-        }
 
-        public Task PingAsync(CancellationToken cancellationToken)
-        {
-            return InternalClient.PingAsync(cancellationToken);
-        }
-
-        public async Task<MqttClientPublishResult> PublishAsync(MqttApplicationMessage applicationMessage, CancellationToken cancellationToken)
-        {
-            ThrowIfDisposed();
-
-            if (applicationMessage == null) throw new ArgumentNullException(nameof(applicationMessage));
-
-            await PublishAsync(new ManagedMqttApplicationMessageBuilder().WithApplicationMessage(applicationMessage).Build()).ConfigureAwait(false);
-            return new MqttClientPublishResult();
-        }
-
-        public async Task PublishAsync(ManagedMqttApplicationMessage applicationMessage)
-        {
-            ThrowIfDisposed();
-
-            if (applicationMessage == null) throw new ArgumentNullException(nameof(applicationMessage));
-            if (Options == null) throw new InvalidOperationException("call StartAsync before publishing messages");
+            if (Options == null)
+            {
+                throw new InvalidOperationException("call StartAsync before publishing messages");
+            }
 
             MqttTopicValidator.ThrowIfInvalid(applicationMessage.ApplicationMessage.Topic);
 
@@ -210,11 +203,77 @@ namespace MQTTnet.Extensions.ManagedClient
             }
         }
 
-        public Task SubscribeAsync(IEnumerable<MqttTopicFilter> topicFilters)
+        public Task PingAsync(CancellationToken cancellationToken)
+        {
+            return InternalClient.PingAsync(cancellationToken);
+        }
+
+        public async Task StartAsync(ManagedMqttClientOptions options)
         {
             ThrowIfDisposed();
 
-            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
+            if (options == null)
+            {
+                throw new ArgumentNullException(nameof(options));
+            }
+
+            if (options.ClientOptions == null)
+            {
+                throw new ArgumentException("The client options are not set.", nameof(options));
+            }
+
+            if (!_maintainConnectionTask?.IsCompleted ?? false)
+            {
+                throw new InvalidOperationException("The managed client is already started.");
+            }
+
+            Options = options;
+
+            if (options.Storage != null)
+            {
+                _storageManager = new ManagedMqttClientStorageManager(options.Storage);
+                var messages = await _storageManager.LoadQueuedMessagesAsync().ConfigureAwait(false);
+
+                foreach (var message in messages)
+                {
+                    _messageQueue.Enqueue(message);
+                }
+            }
+
+            var cancellationTokenSource = new CancellationTokenSource();
+            var cancellationToken = cancellationTokenSource.Token;
+            _connectionCancellationToken = cancellationTokenSource;
+
+            _maintainConnectionTask = Task.Run(() => MaintainConnectionAsync(cancellationToken), cancellationToken);
+            _maintainConnectionTask.RunInBackground(_logger);
+
+            _logger.Info("Started");
+        }
+
+        public async Task StopAsync()
+        {
+            ThrowIfDisposed();
+
+            StopPublishing();
+            StopMaintainingConnection();
+
+            _messageQueue.Clear();
+
+            if (_maintainConnectionTask != null)
+            {
+                await Task.WhenAny(_maintainConnectionTask);
+                _maintainConnectionTask = null;
+            }
+        }
+
+        public Task SubscribeAsync(ICollection<MqttTopicFilter> topicFilters)
+        {
+            ThrowIfDisposed();
+
+            if (topicFilters == null)
+            {
+                throw new ArgumentNullException(nameof(topicFilters));
+            }
 
             foreach (var topicFilter in topicFilters)
             {
@@ -235,11 +294,14 @@ namespace MQTTnet.Extensions.ManagedClient
             return Task.FromResult(0);
         }
 
-        public Task UnsubscribeAsync(IEnumerable<string> topics)
+        public Task UnsubscribeAsync(ICollection<string> topics)
         {
             ThrowIfDisposed();
 
-            if (topics == null) throw new ArgumentNullException(nameof(topics));
+            if (topics == null)
+            {
+                throw new ArgumentNullException(nameof(topics));
+            }
 
             lock (_subscriptions)
             {
@@ -277,6 +339,23 @@ namespace MQTTnet.Extensions.ManagedClient
             base.Dispose(disposing);
         }
 
+        static TimeSpan GetRemainingTime(DateTime endTime)
+        {
+            var remainingTime = endTime - DateTime.UtcNow;
+            return remainingTime < TimeSpan.Zero ? TimeSpan.Zero : remainingTime;
+        }
+
+        async Task HandleSubscriptionExceptionAsync(Exception exception)
+        {
+            _logger.Warning(exception, "Synchronizing subscriptions failed.");
+
+            var synchronizingSubscriptionsFailedHandler = SynchronizingSubscriptionsFailedHandler;
+            if (SynchronizingSubscriptionsFailedHandler != null)
+            {
+                await synchronizingSubscriptionsFailedHandler.HandleSynchronizingSubscriptionsFailedAsync(new ManagedProcessFailedEventArgs(exception)).ConfigureAwait(false);
+            }
+        }
+
         async Task MaintainConnectionAsync(CancellationToken cancellationToken)
         {
             try
@@ -299,9 +378,9 @@ namespace MQTTnet.Extensions.ManagedClient
                 {
                     try
                     {
-                        using (var disconnectTimeout = new CancellationTokenSource(Options.ClientOptions.CommunicationTimeout))
+                        using (var disconnectTimeout = new CancellationTokenSource(Options.ClientOptions.Timeout))
                         {
-                            await InternalClient.DisconnectAsync(disconnectTimeout.Token).ConfigureAwait(false);
+                            await InternalClient.DisconnectAsync(new MqttClientDisconnectOptions(), disconnectTimeout.Token).ConfigureAwait(false);
                         }
                     }
                     catch (OperationCanceledException)
@@ -326,49 +405,6 @@ namespace MQTTnet.Extensions.ManagedClient
             }
         }
 
-        async Task TryMaintainConnectionAsync(CancellationToken cancellationToken)
-        {
-            try
-            {
-                var connectionState = await ReconnectIfRequiredAsync(cancellationToken).ConfigureAwait(false);
-                if (connectionState == ReconnectionResult.NotConnected)
-                {
-                    StopPublishing();
-                    await Task.Delay(Options.AutoReconnectDelay, cancellationToken).ConfigureAwait(false);
-                    return;
-                }
-
-                if (connectionState == ReconnectionResult.Reconnected)
-                {
-                    await PublishReconnectSubscriptionsAsync().ConfigureAwait(false);
-                    StartPublishing();
-                    return;
-                }
-
-                if (connectionState == ReconnectionResult.Recovered)
-                {
-                    StartPublishing();
-                    return;
-                }
-
-                if (connectionState == ReconnectionResult.StillConnected)
-                {
-                    await PublishSubscriptionsAsync(Options.ConnectionCheckInterval, cancellationToken).ConfigureAwait(false);
-                }
-            }
-            catch (OperationCanceledException)
-            {
-            }
-            catch (MqttCommunicationException exception)
-            {
-                _logger.Warning(exception, "Communication error while maintaining connection.");
-            }
-            catch (Exception exception)
-            {
-                _logger.Error(exception, "Error exception while maintaining connection.");
-            }
-        }
-
         async Task PublishQueuedMessagesAsync(CancellationToken cancellationToken)
         {
             try
@@ -407,6 +443,259 @@ namespace MQTTnet.Extensions.ManagedClient
             }
         }
 
+        async Task PublishReconnectSubscriptionsAsync()
+        {
+            _logger.Info("Publishing subscriptions at reconnect");
+
+            try
+            {
+                if (_reconnectSubscriptions.Any())
+                {
+                    var subscriptions = _reconnectSubscriptions.Select(
+                        i => new MqttTopicFilter
+                        {
+                            Topic = i.Key,
+                            QualityOfServiceLevel = i.Value
+                        });
+
+                    var topicFilters = new List<MqttTopicFilter>();
+
+                    foreach (var sub in subscriptions)
+                    {
+                        topicFilters.Add(sub);
+
+                        if (topicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
+                        {
+                            await SendSubscribeUnsubscribe(topicFilters, null).ConfigureAwait(false);
+                            topicFilters.Clear();
+                        }
+                    }
+
+                    await SendSubscribeUnsubscribe(topicFilters, null).ConfigureAwait(false);
+                }
+            }
+            catch (Exception exception)
+            {
+                await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
+            }
+        }
+
+        async Task PublishSubscriptionsAsync(TimeSpan timeout, CancellationToken cancellationToken)
+        {
+            var endTime = DateTime.UtcNow + timeout;
+
+            while (await _subscriptionsQueuedSignal.WaitAsync(GetRemainingTime(endTime), cancellationToken).ConfigureAwait(false))
+            {
+                List<MqttTopicFilter> subscriptions;
+                HashSet<string> unsubscriptions;
+
+                lock (_subscriptions)
+                {
+                    subscriptions = _subscriptions.Select(
+                            i => new MqttTopicFilter
+                            {
+                                Topic = i.Key,
+                                QualityOfServiceLevel = i.Value
+                            })
+                        .ToList();
+
+                    _subscriptions.Clear();
+
+                    unsubscriptions = new HashSet<string>(_unsubscriptions);
+                    _unsubscriptions.Clear();
+                }
+
+                if (!subscriptions.Any() && !unsubscriptions.Any())
+                {
+                    continue;
+                }
+
+                _logger.Verbose("Publishing {0} added and {1} removed subscriptions", subscriptions.Count, unsubscriptions.Count);
+
+                foreach (var unsubscription in unsubscriptions)
+                {
+                    _reconnectSubscriptions.Remove(unsubscription);
+                }
+
+                foreach (var subscription in subscriptions)
+                {
+                    _reconnectSubscriptions[subscription.Topic] = subscription.QualityOfServiceLevel;
+                }
+
+                var addedTopicFilters = new List<MqttTopicFilter>();
+                foreach (var subscription in subscriptions)
+                {
+                    addedTopicFilters.Add(subscription);
+
+                    if (addedTopicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
+                    {
+                        await SendSubscribeUnsubscribe(addedTopicFilters, null).ConfigureAwait(false);
+                        addedTopicFilters.Clear();
+                    }
+                }
+
+                await SendSubscribeUnsubscribe(addedTopicFilters, null).ConfigureAwait(false);
+
+                var removedTopicFilters = new List<string>();
+                foreach (var unSub in unsubscriptions)
+                {
+                    removedTopicFilters.Add(unSub);
+
+                    if (removedTopicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
+                    {
+                        await SendSubscribeUnsubscribe(null, removedTopicFilters).ConfigureAwait(false);
+                        removedTopicFilters.Clear();
+                    }
+                }
+
+                await SendSubscribeUnsubscribe(null, removedTopicFilters).ConfigureAwait(false);
+            }
+        }
+
+        async Task<ReconnectionResult> ReconnectIfRequiredAsync(CancellationToken cancellationToken)
+        {
+            if (InternalClient.IsConnected)
+            {
+                return ReconnectionResult.StillConnected;
+            }
+
+            MqttClientConnectResult connectResult = null;
+            try
+            {
+                using (var connectTimeout = new CancellationTokenSource(Options.ClientOptions.Timeout))
+                {
+                    connectResult = await InternalClient.ConnectAsync(Options.ClientOptions, connectTimeout.Token).ConfigureAwait(false);
+                }
+
+                if (connectResult.ResultCode != MqttClientConnectResultCode.Success)
+                {
+                    throw new MqttCommunicationException($"Client connected but server denied connection with reason '{connectResult.ResultCode}'.");
+                }
+
+                return connectResult.IsSessionPresent ? ReconnectionResult.Recovered : ReconnectionResult.Reconnected;
+            }
+            catch (Exception exception)
+            {
+                await _connectingFailedEvent.InvokeAsync(new ConnectingFailedEventArgs(connectResult, exception));
+                return ReconnectionResult.NotConnected;
+            }
+        }
+
+        async Task SendSubscribeUnsubscribe(List<MqttTopicFilter> addedSubscriptions, List<string> removedSubscriptions)
+        {
+            try
+            {
+                if (removedSubscriptions != null && removedSubscriptions.Any())
+                {
+                    var unsubscribeOptionsBuilder = new MqttClientUnsubscribeOptionsBuilder();
+
+                    foreach (var removedSubscription in removedSubscriptions)
+                    {
+                        unsubscribeOptionsBuilder.WithTopicFilter(removedSubscription);
+                    }
+
+                    await InternalClient.UnsubscribeAsync(unsubscribeOptionsBuilder.Build()).ConfigureAwait(false);
+                }
+
+                if (addedSubscriptions != null && addedSubscriptions.Any())
+                {
+                    var subscribeOptionsBuilder = new MqttClientSubscribeOptionsBuilder();
+
+                    foreach (var addedSubscription in addedSubscriptions)
+                    {
+                        subscribeOptionsBuilder.WithTopicFilter(addedSubscription);
+                    }
+
+                    await InternalClient.SubscribeAsync(subscribeOptionsBuilder.Build()).ConfigureAwait(false);
+                }
+            }
+            catch (Exception exception)
+            {
+                await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
+            }
+        }
+
+        void StartPublishing()
+        {
+            StopPublishing();
+
+            var cancellationTokenSource = new CancellationTokenSource();
+            var cancellationToken = cancellationTokenSource.Token;
+            _publishingCancellationToken = cancellationTokenSource;
+
+            Task.Run(() => PublishQueuedMessagesAsync(cancellationToken), cancellationToken).RunInBackground(_logger);
+        }
+
+        void StopMaintainingConnection()
+        {
+            try
+            {
+                _connectionCancellationToken?.Cancel(false);
+            }
+            finally
+            {
+                _connectionCancellationToken?.Dispose();
+                _connectionCancellationToken = null;
+            }
+        }
+
+        void StopPublishing()
+        {
+            try
+            {
+                _publishingCancellationToken?.Cancel(false);
+            }
+            finally
+            {
+                _publishingCancellationToken?.Dispose();
+                _publishingCancellationToken = null;
+            }
+        }
+
+        async Task TryMaintainConnectionAsync(CancellationToken cancellationToken)
+        {
+            try
+            {
+                var oldConnectionState = InternalClient.IsConnected;
+                var connectionState = await ReconnectIfRequiredAsync(cancellationToken).ConfigureAwait(false);
+                
+                if (connectionState == ReconnectionResult.NotConnected)
+                {
+                    StopPublishing();
+                    await Task.Delay(Options.AutoReconnectDelay, cancellationToken).ConfigureAwait(false);
+                }
+                else if (connectionState == ReconnectionResult.Reconnected)
+                {
+                    await PublishReconnectSubscriptionsAsync().ConfigureAwait(false);
+                    StartPublishing();
+                }
+                else if (connectionState == ReconnectionResult.Recovered)
+                {
+                    StartPublishing();
+                }
+                else if (connectionState == ReconnectionResult.StillConnected)
+                {
+                    await PublishSubscriptionsAsync(Options.ConnectionCheckInterval, cancellationToken).ConfigureAwait(false);
+                }
+
+                if (oldConnectionState != InternalClient.IsConnected)
+                {
+                    await _connectionStateChangedEvent.InvokeAsync(EventArgs.Empty).ConfigureAwait(false);
+                }
+            }
+            catch (OperationCanceledException)
+            {
+            }
+            catch (MqttCommunicationException exception)
+            {
+                _logger.Warning(exception, "Communication error while maintaining connection.");
+            }
+            catch (Exception exception)
+            {
+                _logger.Error(exception, "Error exception while maintaining connection.");
+            }
+        }
+
         async Task TryPublishQueuedMessageAsync(ManagedMqttApplicationMessage message)
         {
             Exception transmitException = null;
@@ -463,220 +752,12 @@ namespace MQTTnet.Extensions.ManagedClient
             }
             finally
             {
-                var eventHandler = ApplicationMessageProcessedHandler;
-                if (eventHandler != null)
+                if (_applicationMessageProcessedEvent.HasHandlers)
                 {
-                    var eventArguments = new ApplicationMessageProcessedEventArgs(message, transmitException);
-                    await eventHandler.HandleApplicationMessageProcessedAsync(eventArguments).ConfigureAwait(false);
+                    var eventArgs = new ApplicationMessageProcessedEventArgs(message, transmitException);
+                    await _applicationMessageProcessedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
                 }
             }
         }
-
-        async Task PublishSubscriptionsAsync(TimeSpan timeout, CancellationToken cancellationToken)
-        {
-            var endTime = DateTime.UtcNow + timeout;
-
-            while (await _subscriptionsQueuedSignal.WaitAsync(GetRemainingTime(endTime), cancellationToken).ConfigureAwait(false))
-            {
-                List<MqttTopicFilter> subscriptions;
-                HashSet<string> unsubscriptions;
-
-                lock (_subscriptions)
-                {
-                    subscriptions = _subscriptions.Select(i => new MqttTopicFilter
-                    {
-                        Topic = i.Key, 
-                        QualityOfServiceLevel = i.Value
-                    }).ToList();
-                    
-                    _subscriptions.Clear();
-                    
-                    unsubscriptions = new HashSet<string>(_unsubscriptions);
-                    _unsubscriptions.Clear();
-                }
-
-                if (!subscriptions.Any() && !unsubscriptions.Any())
-                {
-                    continue;
-                }
-
-                _logger.Verbose("Publishing {0} added and {1} removed subscriptions", subscriptions.Count, unsubscriptions.Count);
-
-                foreach (var unsubscription in unsubscriptions)
-                {
-                    _reconnectSubscriptions.Remove(unsubscription);
-                }
-
-                foreach (var subscription in subscriptions)
-                {
-                    _reconnectSubscriptions[subscription.Topic] = subscription.QualityOfServiceLevel;
-                }
-
-                var addedTopicFilters = new List<MqttTopicFilter>();
-                foreach (var subscription in subscriptions)
-                {
-                    addedTopicFilters.Add(subscription);
-                    
-                    if (addedTopicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
-                    {
-                        await SendSubscribeUnsubscribe(addedTopicFilters, null).ConfigureAwait(false);
-                        addedTopicFilters.Clear();
-                    }
-                }
-
-                await SendSubscribeUnsubscribe(addedTopicFilters, null).ConfigureAwait(false);
-
-                var removedTopicFilters = new List<string>();
-                foreach (var unSub in unsubscriptions)
-                {
-                    removedTopicFilters.Add(unSub);
-                    
-                    if (removedTopicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
-                    {
-                        await SendSubscribeUnsubscribe(null, removedTopicFilters).ConfigureAwait(false);
-                        removedTopicFilters.Clear();
-                    }
-                }
-
-                await SendSubscribeUnsubscribe(null, removedTopicFilters).ConfigureAwait(false);
-            }
-        }
-
-        async Task SendSubscribeUnsubscribe(List<MqttTopicFilter> addedSubscriptions, List<string> removedSubscriptions)
-        {
-            try
-            {
-                if (removedSubscriptions != null && removedSubscriptions.Any())
-                {
-                    await InternalClient.UnsubscribeAsync(removedSubscriptions.ToArray()).ConfigureAwait(false);
-                }
-
-                if (addedSubscriptions != null && addedSubscriptions.Any())
-                {
-                    await InternalClient.SubscribeAsync(addedSubscriptions.ToArray()).ConfigureAwait(false);
-                }
-            }
-            catch (Exception exception)
-            {
-                await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
-            }
-        }
-
-        async Task PublishReconnectSubscriptionsAsync()
-        {
-            _logger.Info("Publishing subscriptions at reconnect");
-
-            try
-            {
-                if (_reconnectSubscriptions.Any())
-                {
-                    var subscriptions = _reconnectSubscriptions.Select(i => new MqttTopicFilter
-                    {
-                        Topic = i.Key, 
-                        QualityOfServiceLevel = i.Value
-                    });
-                    
-                    var topicFilters = new List<MqttTopicFilter>();
-                    
-                    foreach (var sub in subscriptions)
-                    {
-                        topicFilters.Add(sub);
-                        
-                        if (topicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
-                        {
-                            await SendSubscribeUnsubscribe(topicFilters, null).ConfigureAwait(false);
-                            topicFilters.Clear();
-                        }
-                    }
-
-                    await SendSubscribeUnsubscribe(topicFilters, null).ConfigureAwait(false);
-                }
-            }
-            catch (Exception exception)
-            {
-                await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
-            }
-        }
-
-        async Task HandleSubscriptionExceptionAsync(Exception exception)
-        {
-            _logger.Warning(exception, "Synchronizing subscriptions failed.");
-
-            var synchronizingSubscriptionsFailedHandler = SynchronizingSubscriptionsFailedHandler;
-            if (SynchronizingSubscriptionsFailedHandler != null)
-            {
-                await synchronizingSubscriptionsFailedHandler.HandleSynchronizingSubscriptionsFailedAsync(new ManagedProcessFailedEventArgs(exception)).ConfigureAwait(false);
-            }
-        }
-
-        async Task<ReconnectionResult> ReconnectIfRequiredAsync(CancellationToken cancellationToken)
-        {
-            if (InternalClient.IsConnected)
-            {
-                return ReconnectionResult.StillConnected;
-            }
-
-            try
-            {
-                var result = await InternalClient.ConnectAsync(Options.ClientOptions, cancellationToken).ConfigureAwait(false);
-                return result.IsSessionPresent ? ReconnectionResult.Recovered : ReconnectionResult.Reconnected;
-            }
-            catch (Exception exception)
-            {
-                var connectingFailedHandler = ConnectingFailedHandler;
-                if (connectingFailedHandler != null)
-                {
-                    await connectingFailedHandler.HandleConnectingFailedAsync(new ManagedProcessFailedEventArgs(exception)).ConfigureAwait(false);
-                }
-
-                return ReconnectionResult.NotConnected;
-            }
-        }
-
-        void StartPublishing()
-        {
-            if (_publishingCancellationToken != null)
-            {
-                StopPublishing();
-            }
-
-            var cancellationTokenSource = new CancellationTokenSource();
-            var cancellationToken = cancellationTokenSource.Token;
-            _publishingCancellationToken = cancellationTokenSource;
-
-            Task.Run(() => PublishQueuedMessagesAsync(cancellationToken), cancellationToken).RunInBackground(_logger);
-        }
-
-        void StopPublishing()
-        {
-            try
-            {
-                _publishingCancellationToken?.Cancel(false);
-            }
-            finally
-            {
-                _publishingCancellationToken?.Dispose();
-                _publishingCancellationToken = null;
-            }
-        }
-
-        void StopMaintainingConnection()
-        {
-            try
-            {
-                _connectionCancellationToken?.Cancel(false);
-            }
-            finally
-            {
-                _connectionCancellationToken?.Dispose();
-                _connectionCancellationToken = null;
-            }
-        }
-
-        static TimeSpan GetRemainingTime(DateTime endTime)
-        {
-            var remainingTime = endTime - DateTime.UtcNow;
-            return remainingTime < TimeSpan.Zero ? TimeSpan.Zero : remainingTime;
-        }
     }
 }

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClientExtensions.cs

@@ -1,232 +1,78 @@
-using MQTTnet.Client.Connecting;
-using MQTTnet.Client.Disconnecting;
-using MQTTnet.Client.Publishing;
-using MQTTnet.Client.Receiving;
-using MQTTnet.Protocol;
+// 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;
 using System.Collections.Generic;
-using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.Packets;
+using MQTTnet.Protocol;
 
 namespace MQTTnet.Extensions.ManagedClient
 {
     public static class ManagedMqttClientExtensions
     {
-        public static IManagedMqttClient UseConnectedHandler(this IManagedMqttClient client, Func<MqttClientConnectedEventArgs, Task> handler)
+        public static Task EnqueueAsync(
+            this ManagedMqttClient managedMqttClient,
+            string topic,
+            string payload = null,
+            MqttQualityOfServiceLevel qualityOfServiceLevel = MqttQualityOfServiceLevel.AtMostOnce,
+            bool retain = false)
         {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-
-            if (handler == null)
+            if (managedMqttClient == null)
             {
-                return client.UseConnectedHandler((IMqttClientConnectedHandler)null);
+                throw new ArgumentNullException(nameof(managedMqttClient));
             }
 
-            return client.UseConnectedHandler(new MqttClientConnectedHandlerDelegate(handler));
-        }
-
-        public static IManagedMqttClient UseConnectedHandler(this IManagedMqttClient client, Action<MqttClientConnectedEventArgs> handler)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-
-            if (handler == null)
+            if (topic == null)
             {
-                return client.UseConnectedHandler((IMqttClientConnectedHandler)null);
+                throw new ArgumentNullException(nameof(topic));
             }
 
-            return client.UseConnectedHandler(new MqttClientConnectedHandlerDelegate(handler));
-        }
-
-        public static IManagedMqttClient UseConnectedHandler(this IManagedMqttClient client, IMqttClientConnectedHandler handler)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-
-            client.ConnectedHandler = handler;
-            return client;
-        }
-
-        public static IManagedMqttClient UseDisconnectedHandler(this IManagedMqttClient client, Func<MqttClientDisconnectedEventArgs, Task> handler)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-
-            if (handler == null)
-            {
-                return client.UseDisconnectedHandler((IMqttClientDisconnectedHandler)null);
-            }
-
-            return client.UseDisconnectedHandler(new MqttClientDisconnectedHandlerDelegate(handler));
-        }
-
-        public static IManagedMqttClient UseDisconnectedHandler(this IManagedMqttClient client, Action<MqttClientDisconnectedEventArgs> handler)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-
-            if (handler == null)
-            {
-                return client.UseDisconnectedHandler((IMqttClientDisconnectedHandler)null);
-            }
-
-            return client.UseDisconnectedHandler(new MqttClientDisconnectedHandlerDelegate(handler));
-        }
-
-        public static IManagedMqttClient UseDisconnectedHandler(this IManagedMqttClient client, IMqttClientDisconnectedHandler handler)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-
-            client.DisconnectedHandler = handler;
-            return client;
-        }
-
-        public static TReceiver UseApplicationMessageReceivedHandler<TReceiver>(this TReceiver receiver, Func<MqttApplicationMessageReceivedEventArgs, Task> handler)
-            where TReceiver : IApplicationMessageReceiver
-        {
-            if (receiver == null) throw new ArgumentNullException(nameof(receiver));
-
-            if (handler == null)
-            {
-                return receiver.UseApplicationMessageReceivedHandler((IMqttApplicationMessageReceivedHandler)null);
-            }
-
-            return receiver.UseApplicationMessageReceivedHandler(new MqttApplicationMessageReceivedHandlerDelegate(handler));
-        }
-
-        public static TReceiver UseApplicationMessageReceivedHandler<TReceiver>(this TReceiver receiver, Action<MqttApplicationMessageReceivedEventArgs> handler)
-            where TReceiver : IApplicationMessageReceiver
-        {
-            if (receiver == null) throw new ArgumentNullException(nameof(receiver));
-
-            if (handler == null)
-            {
-                return receiver.UseApplicationMessageReceivedHandler((IMqttApplicationMessageReceivedHandler)null);
-            }
-
-            return receiver.UseApplicationMessageReceivedHandler(new MqttApplicationMessageReceivedHandlerDelegate(handler));
-        }
-
-        public static TReceiver UseApplicationMessageReceivedHandler<TReceiver>(this TReceiver receiver, IMqttApplicationMessageReceivedHandler handler)
-            where TReceiver : IApplicationMessageReceiver
-        {
-            if (receiver == null) throw new ArgumentNullException(nameof(receiver));
-
-            receiver.ApplicationMessageReceivedHandler = handler;
-            return receiver;
-        }
-
-        public static Task SubscribeAsync(this IManagedMqttClient client, params MqttTopicFilter[] topicFilters)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-
-            return client.SubscribeAsync(topicFilters);
-        }
-
-        public static Task SubscribeAsync(this IManagedMqttClient client, string topic, MqttQualityOfServiceLevel qualityOfServiceLevel)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-            if (topic == null) throw new ArgumentNullException(nameof(topic));
-
-            return client.SubscribeAsync(new MqttTopicFilterBuilder().WithTopic(topic).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
-        }
-
-        public static Task SubscribeAsync(this IManagedMqttClient client, string topic)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-            if (topic == null) throw new ArgumentNullException(nameof(topic));
-
-            return client.SubscribeAsync(new MqttTopicFilterBuilder().WithTopic(topic).Build());
-        }
-
-        public static Task UnsubscribeAsync(this IManagedMqttClient client, params string[] topicFilters)
-        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
-
-            return client.UnsubscribeAsync(topicFilters);
-        }
-
-        public static async Task PublishAsync(this IApplicationMessagePublisher publisher, IEnumerable<MqttApplicationMessage> applicationMessages)
-        {
-            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
-            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
-
-            foreach (var applicationMessage in applicationMessages)
-            {
-                await publisher.PublishAsync(applicationMessage).ConfigureAwait(false);
-            }
-        }
-
-        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, MqttApplicationMessage applicationMessage)
-        {
-            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
-            if (applicationMessage == null) throw new ArgumentNullException(nameof(applicationMessage));
-
-            return publisher.PublishAsync(applicationMessage, CancellationToken.None);
-        }
-
-        public static async Task PublishAsync(this IApplicationMessagePublisher publisher, params MqttApplicationMessage[] applicationMessages)
-        {
-            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
-            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
-
-            foreach (var applicationMessage in applicationMessages)
-            {
-                await publisher.PublishAsync(applicationMessage, CancellationToken.None).ConfigureAwait(false);
-            }
-        }
-
-        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, string topic)
-        {
-            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
-            if (topic == null) throw new ArgumentNullException(nameof(topic));
-
-            return publisher.PublishAsync(builder => builder
-                .WithTopic(topic));
-        }
-
-        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload)
-        {
-            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
-            if (topic == null) throw new ArgumentNullException(nameof(topic));
-
-            return publisher.PublishAsync(builder => builder
-                .WithTopic(topic)
-                .WithPayload(payload));
-        }
-
-        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
-        {
-            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
-            if (topic == null) throw new ArgumentNullException(nameof(topic));
-
-            return publisher.PublishAsync(builder => builder
-                .WithTopic(topic)
-                .WithPayload(payload)
-                .WithQualityOfServiceLevel(qualityOfServiceLevel));
-        }
-
-        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel, bool retain)
-        {
-            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
-            if (topic == null) throw new ArgumentNullException(nameof(topic));
-
-            return publisher.PublishAsync(builder => builder
-                .WithTopic(topic)
+            var applicationMessage = new MqttApplicationMessageBuilder().WithTopic(topic)
                 .WithPayload(payload)
+                .WithRetainFlag(retain)
                 .WithQualityOfServiceLevel(qualityOfServiceLevel)
-                .WithRetainFlag(retain));
+                .Build();
+
+            return managedMqttClient.EnqueueAsync(applicationMessage);
         }
 
-        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, Func<MqttApplicationMessageBuilder, MqttApplicationMessageBuilder> builder, CancellationToken cancellationToken)
+        public static Task SubscribeAsync(
+            this ManagedMqttClient managedMqttClient,
+            string topic,
+            MqttQualityOfServiceLevel qualityOfServiceLevel = MqttQualityOfServiceLevel.AtMostOnce)
         {
-            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
+            if (managedMqttClient == null)
+            {
+                throw new ArgumentNullException(nameof(managedMqttClient));
+            }
 
-            var message = builder(new MqttApplicationMessageBuilder()).Build();
-            return publisher.PublishAsync(message, cancellationToken);
+            if (topic == null)
+            {
+                throw new ArgumentNullException(nameof(topic));
+            }
+
+            return managedMqttClient.SubscribeAsync(
+                new List<MqttTopicFilter>
+                {
+                    new MqttTopicFilterBuilder().WithTopic(topic).WithQualityOfServiceLevel(qualityOfServiceLevel).Build()
+                });
         }
 
-        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, Func<MqttApplicationMessageBuilder, MqttApplicationMessageBuilder> builder)
+        public static Task UnsubscribeAsync(this ManagedMqttClient managedMqttClient, string topic)
         {
-            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
+            if (managedMqttClient == null)
+            {
+                throw new ArgumentNullException(nameof(managedMqttClient));
+            }
 
-            var message = builder(new MqttApplicationMessageBuilder()).Build();
-            return publisher.PublishAsync(message, CancellationToken.None);
+            if (topic == null)
+            {
+                throw new ArgumentNullException(nameof(topic));
+            }
+
+            return managedMqttClient.UnsubscribeAsync(new List<string> { topic });
         }
     }
-}
+}

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClientOptions.cs

@@ -1,12 +1,16 @@
+// 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;
-using MQTTnet.Client.Options;
+using MQTTnet.Client;
 using MQTTnet.Server;
 
 namespace MQTTnet.Extensions.ManagedClient
 {
-    public sealed class ManagedMqttClientOptions : IManagedMqttClientOptions
+    public sealed class ManagedMqttClientOptions
     {
-        public IMqttClientOptions ClientOptions { get; set; }
+        public MqttClientOptions ClientOptions { get; set; }
 
         public TimeSpan AutoReconnectDelay { get; set; } = TimeSpan.FromSeconds(5);
 
@@ -18,6 +22,10 @@ namespace MQTTnet.Extensions.ManagedClient
 
         public MqttPendingMessagesOverflowStrategy PendingMessagesOverflowStrategy { get; set; } = MqttPendingMessagesOverflowStrategy.DropNewMessage;
 
+        /// <summary>
+        /// Defines the maximum amount of topic filters which will be sent in a SUBSCRIBE/UNSUBSCRIBE packet.
+        /// Amazon AWS limits this number to 8. The default is int.MaxValue.
+        /// </summary>
         public int MaxTopicFiltersInSubscribeUnsubscribePackets { get; set; } = int.MaxValue;
     }
 }

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClientOptionsBuilder.cs

@@ -1,5 +1,9 @@
+// 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;
-using MQTTnet.Client.Options;
+using MQTTnet.Client;
 using MQTTnet.Server;
 
 namespace MQTTnet.Extensions.ManagedClient
@@ -33,7 +37,7 @@ namespace MQTTnet.Extensions.ManagedClient
             return this;
         }
 
-        public ManagedMqttClientOptionsBuilder WithClientOptions(IMqttClientOptions value)
+        public ManagedMqttClientOptionsBuilder WithClientOptions(MqttClientOptions value)
         {
             if (_clientOptionsBuilder != null)
             {

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClientStorageManager.cs

@@ -1,4 +1,8 @@
-using System;
+// 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;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;

Source/MQTTnet.Extensions.ManagedClient/ManagedProcessFailedEventArgs.cs

@@ -1,4 +1,8 @@
-using System;
+// 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 MQTTnet.Extensions.ManagedClient
 {

Source/MQTTnet.Extensions.ManagedClient/MqttFactoryExtensions.cs

@@ -1,18 +1,28 @@
-using System;
-using MQTTnet.Diagnostics.Logger;
+// 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;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
 
 namespace MQTTnet.Extensions.ManagedClient
 {
     public static class MqttFactoryExtensions
     {
-        public static IManagedMqttClient CreateManagedMqttClient(this IMqttFactory factory)
+        public static ManagedMqttClient CreateManagedMqttClient(this MqttFactory factory, MqttClient mqttClient = null)
         {
             if (factory == null) throw new ArgumentNullException(nameof(factory));
 
-            return new ManagedMqttClient(factory.CreateMqttClient(), factory.DefaultLogger);
+            if (mqttClient == null)
+            {
+                return new ManagedMqttClient(factory.CreateMqttClient(), factory.DefaultLogger);    
+            }
+            
+            return new ManagedMqttClient(mqttClient, factory.DefaultLogger);
         }
-
-        public static IManagedMqttClient CreateManagedMqttClient(this IMqttFactory factory, IMqttNetLogger logger)
+        
+        public static ManagedMqttClient CreateManagedMqttClient(this MqttFactory factory, IMqttNetLogger logger)
         {
             if (factory == null) throw new ArgumentNullException(nameof(factory));
             if (logger == null) throw new ArgumentNullException(nameof(logger));

Source/MQTTnet.Extensions.ManagedClient/ReconnectionResult.cs

@@ -1,4 +1,8 @@
-namespace MQTTnet.Extensions.ManagedClient
+// 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.
+
+namespace MQTTnet.Extensions.ManagedClient
 {
     public enum ReconnectionResult
     {

Source/MQTTnet.Extensions.ManagedClient/SynchronizingSubscriptionsFailedHandlerDelegate.cs

@@ -1,4 +1,8 @@
-using System;
+// 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;
 using System.Threading.Tasks;
 
 namespace MQTTnet.Extensions.ManagedClient

Source/MQTTnet.Extensions.Rpc/IMqttRpcClient.cs

@@ -1,14 +0,0 @@
-using System;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Protocol;
-
-namespace MQTTnet.Extensions.Rpc
-{
-    public interface IMqttRpcClient : IDisposable
-    {
-        Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel);
-
-        Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, CancellationToken cancellationToken);
-    }
-}

Source/MQTTnet.Extensions.Rpc/MQTTnet.Extensions.Rpc.csproj

@@ -1,40 +1,72 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
-    <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1;net5.0</TargetFrameworks>
-    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
-    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' AND '$(SolutionName)' != 'MQTTnet.noUWP' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
-    <Product />
-    <Company />
-    <Authors />
-    <PackageId />
-    <GeneratePackageOnBuild>False</GeneratePackageOnBuild>
-    <SignAssembly>false</SignAssembly>
-    <DelaySign>false</DelaySign>
-    <PublishRepositoryUrl>true</PublishRepositoryUrl>
-    <IncludeSymbols>true</IncludeSymbols>
-    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
-  </PropertyGroup>
+    <PropertyGroup>
+        <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1;netcoreapp3.1;net5.0;net6.0</TargetFrameworks>
+        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
+        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
+        
+        <AssemblyName>MQTTnet.Extensions.Rpc</AssemblyName>
+        <RootNamespace>MQTTnet.Extensions.Rpc</RootNamespace>
+        <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
+        <Company>The contributors of MQTTnet</Company>
+        <Product>MQTTnet</Product>
+        <Description>This is an extension library which allows executing synchronous device calls including a response using MQTTnet.</Description>
+        <Authors>The contributors of MQTTnet</Authors>
+        <PackageId>MQTTnet.Extensions.Rpc</PackageId>
+        <SignAssembly>false</SignAssembly>
+        <DelaySign>false</DelaySign>
+        <PublishRepositoryUrl>true</PublishRepositoryUrl>
+        <IncludeSymbols>true</IncludeSymbols>
+        <SymbolPackageFormat>snupkg</SymbolPackageFormat>
+        <Copyright>Christian Kratky 2016-2022</Copyright>
+        <PackageProjectUrl>https://github.com/dotnet/MQTTnet</PackageProjectUrl>
+        <RepositoryUrl>https://github.com/dotnet/MQTTnet.git</RepositoryUrl>
+        <RepositoryType>git</RepositoryType>
+        <PackageTags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</PackageTags>
+        <NeutralLanguage>en-US</NeutralLanguage>
+        <EnableNETAnalyzers>false</EnableNETAnalyzers>
+        <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
+        <PackageIcon>nuget.png</PackageIcon>
+        <EmbedUntrackedSources>true</EmbedUntrackedSources>
+        <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
+        <PackageLicenseFile>LICENSE</PackageLicenseFile>
+        <PackageReleaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</PackageReleaseNotes>
+        <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
+    </PropertyGroup>
 
-  <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
-    <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
-    <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
-    <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-    <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
-    <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
-    <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
-    <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
-    <DefineConstants>$(DefineConstants);WINDOWS_UWP</DefineConstants>
-    <DefaultLanguage>en</DefaultLanguage>
-    <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
-  </PropertyGroup>
+    <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
+        <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
+        <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
+        <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
+        <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
+        <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
+        <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
+        <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
+        <DefineConstants>$(DefineConstants);WINDOWS_UWP</DefineConstants>
+        <DefaultLanguage>en</DefaultLanguage>
+        <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
+    </PropertyGroup>
 
-  <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
-  </ItemGroup>
+    <ItemGroup>
+        <None Include="..\..\Images\nuget.png">
+            <Pack>True</Pack>
+            <PackagePath>\</PackagePath>
+        </None>
+    </ItemGroup>
 
-  <ItemGroup>
-    <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
-  </ItemGroup>
+    <ItemGroup>
+        <None Include="..\..\LICENSE">
+            <Pack>True</Pack>
+            <PackagePath>\</PackagePath>
+        </None>
+    </ItemGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
+    </ItemGroup>
 
 </Project>

Source/MQTTnet.Extensions.Rpc/MQTTnet.Extensions.Rpc.csproj.DotSettings

@@ -0,0 +1,3 @@
+<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=options/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=options_005Ctopicgeneration/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>

Source/MQTTnet.Extensions.Rpc/MqttFactoryExtensions.cs

@@ -0,0 +1,37 @@
+// 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;
+using MQTTnet.Client;
+
+namespace MQTTnet.Extensions.Rpc
+{
+    public static class MqttFactoryExtensions
+    {
+        public static MqttRpcClient CreateMqttRpcClient(this MqttFactory factory, MqttClient mqttClient)
+        {
+            return factory.CreateMqttRpcClient(mqttClient, new MqttRpcClientOptions
+            {
+                TopicGenerationStrategy = new DefaultMqttRpcClientTopicGenerationStrategy()
+            });
+        }
+
+        public static MqttRpcClient CreateMqttRpcClient(this MqttFactory factory, MqttClient mqttClient, MqttRpcClientOptions rpcClientOptions)
+        {
+            if (factory == null) throw new ArgumentNullException(nameof(factory));
+            
+            if (mqttClient == null)
+            {
+                throw new ArgumentNullException(nameof(mqttClient));
+            }
+
+            if (rpcClientOptions == null)
+            {
+                throw new ArgumentNullException(nameof(rpcClientOptions));
+            }
+
+            return new MqttRpcClient(mqttClient, rpcClientOptions);
+        }
+    }
+}

Source/MQTTnet.Extensions.Rpc/MqttRpcClient.cs

@@ -1,39 +1,30 @@
+// 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 MQTTnet.Client;
 using MQTTnet.Exceptions;
-using MQTTnet.Extensions.Rpc.Options;
-using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
 using MQTTnet.Protocol;
 using System;
 using System.Collections.Concurrent;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Client.Subscribing;
 using MQTTnet.Implementations;
 
 namespace MQTTnet.Extensions.Rpc
 {
-    public sealed class MqttRpcClient : IMqttRpcClient
+    public sealed class MqttRpcClient : IDisposable
     {
         readonly ConcurrentDictionary<string, TaskCompletionSource<byte[]>> _waitingCalls = new ConcurrentDictionary<string, TaskCompletionSource<byte[]>>();
-        readonly IMqttClient _mqttClient;
-        readonly IMqttRpcClientOptions _options;
-        readonly RpcAwareApplicationMessageReceivedHandler _applicationMessageReceivedHandler;
-
-        [Obsolete("Use MqttRpcClient(IMqttClient mqttClient, IMqttRpcClientOptions options).")]
-        public MqttRpcClient(IMqttClient mqttClient) : this(mqttClient, new MqttRpcClientOptions())
-        {
-        }
-
-        public MqttRpcClient(IMqttClient mqttClient, IMqttRpcClientOptions options)
+        readonly MqttClient _mqttClient;
+        readonly MqttRpcClientOptions _options;
+        
+        public MqttRpcClient(MqttClient mqttClient, MqttRpcClientOptions options)
         {
             _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
             _options = options ?? throw new ArgumentNullException(nameof(options));
 
-            _applicationMessageReceivedHandler = new RpcAwareApplicationMessageReceivedHandler(
-                mqttClient.ApplicationMessageReceivedHandler,
-                HandleApplicationMessageReceivedAsync);
-
-            _mqttClient.ApplicationMessageReceivedHandler = _applicationMessageReceivedHandler;
+            _mqttClient.ApplicationMessageReceivedAsync += HandleApplicationMessageReceivedAsync;
         }
 
         public async Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
@@ -59,12 +50,7 @@ namespace MQTTnet.Extensions.Rpc
         public async Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, CancellationToken cancellationToken)
         {
             if (methodName == null) throw new ArgumentNullException(nameof(methodName));
-
-            if (!(_mqttClient.ApplicationMessageReceivedHandler is RpcAwareApplicationMessageReceivedHandler))
-            {
-                throw new InvalidOperationException("The application message received handler was modified.");
-            }
-
+            
             var topicNames = _options.TopicGenerationStrategy.CreateRpcTopics(new TopicGenerationContext
             {
                 MethodName = methodName,
@@ -121,7 +107,7 @@ namespace MQTTnet.Extensions.Rpc
             finally
             {
                 _waitingCalls.TryRemove(responseTopic, out _);
-
+                
                 await _mqttClient.UnsubscribeAsync(responseTopic).ConfigureAwait(false);
             }
         }
@@ -147,7 +133,7 @@ namespace MQTTnet.Extensions.Rpc
 
         public void Dispose()
         {
-            _mqttClient.ApplicationMessageReceivedHandler = _applicationMessageReceivedHandler.OriginalHandler;
+            _mqttClient.ApplicationMessageReceivedAsync -= HandleApplicationMessageReceivedAsync;
 
             foreach (var tcs in _waitingCalls)
             {

Source/MQTTnet.Extensions.Rpc/MqttRpcClientExtensions.cs

@@ -1,4 +1,8 @@
-using System;
+// 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;
 using System.Text;
 using System.Threading.Tasks;
 using MQTTnet.Protocol;
@@ -7,7 +11,7 @@ namespace MQTTnet.Extensions.Rpc
 {
     public static class MqttRpcClientExtensions
     {
-        public static Task<byte[]> ExecuteAsync(this IMqttRpcClient client, TimeSpan timeout, string methodName, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
+        public static Task<byte[]> ExecuteAsync(this MqttRpcClient client, TimeSpan timeout, string methodName, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
         {
             if (client == null) throw new ArgumentNullException(nameof(client));
 

Source/MQTTnet.Extensions.Rpc/Options/IMqttRpcClientOptions.cs

@@ -1,9 +0,0 @@
-using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
-
-namespace MQTTnet.Extensions.Rpc.Options
-{
-    public interface IMqttRpcClientOptions
-    {
-        IMqttRpcClientTopicGenerationStrategy TopicGenerationStrategy { get; set; }
-    }
-}

Source/MQTTnet.Extensions.Rpc/Options/MqttRpcClientOptions.cs

@@ -1,8 +1,10 @@
-using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+// 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.
 
-namespace MQTTnet.Extensions.Rpc.Options
+namespace MQTTnet.Extensions.Rpc
 {
-    public sealed class MqttRpcClientOptions : IMqttRpcClientOptions
+    public sealed class MqttRpcClientOptions
     {
         public IMqttRpcClientTopicGenerationStrategy TopicGenerationStrategy { get; set; } = new DefaultMqttRpcClientTopicGenerationStrategy();
     }

Source/MQTTnet.Extensions.Rpc/Options/MqttRpcClientOptionsBuilder.cs

@@ -1,7 +1,10 @@
-using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+// 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 MQTTnet.Extensions.Rpc.Options
+namespace MQTTnet.Extensions.Rpc
 {
     public sealed class MqttRpcClientOptionsBuilder
     {
@@ -14,7 +17,7 @@ namespace MQTTnet.Extensions.Rpc.Options
             return this;
         }
 
-        public IMqttRpcClientOptions Build()
+        public MqttRpcClientOptions Build()
         {
             return new MqttRpcClientOptions
             {

Source/MQTTnet.Extensions.Rpc/Options/MqttRpcTopicPair.cs

@@ -1,4 +1,8 @@
-namespace MQTTnet.Extensions.Rpc.Options
+// 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.
+
+namespace MQTTnet.Extensions.Rpc
 {
     public sealed class MqttRpcTopicPair
     {

Source/MQTTnet.Extensions.Rpc/Options/TopicGeneration/DefaultMqttRpcClientTopicGenerationStrategy.cs

@@ -1,6 +1,10 @@
-using System;
+// 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.
 
-namespace MQTTnet.Extensions.Rpc.Options.TopicGeneration
+using System;
+
+namespace MQTTnet.Extensions.Rpc
 {
     public sealed class DefaultMqttRpcClientTopicGenerationStrategy : IMqttRpcClientTopicGenerationStrategy
     {

Source/MQTTnet.Extensions.Rpc/Options/TopicGeneration/IMqttRpcClientTopicGenerationStrategy.cs

@@ -1,4 +1,8 @@
-namespace MQTTnet.Extensions.Rpc.Options.TopicGeneration
+// 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.
+
+namespace MQTTnet.Extensions.Rpc
 {
     public interface IMqttRpcClientTopicGenerationStrategy
     {