fixed #421

Build/MQTTnet.AspNetCore.nuspec

@@ -10,7 +10,8 @@
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>This is a support library to integrate MQTTnet into AspNetCore.</description>
-    <releaseNotes>* For more release notes please check the MQTTnet release notes.
+    <releaseNotes> * For more release notes please check the MQTTnet release notes.
+ * [Server] fixed cpu spike in case a client disconnectes (issue 421)
     </releaseNotes>
     <copyright>Copyright Christian Kratky 2016-2018</copyright>
     <tags>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</tags>

Source/MQTTnet.AspnetCore/MqttConnectionContext.cs

@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Connections;
 using MQTTnet.Adapter;
 using MQTTnet.AspNetCore.Client.Tcp;
+using MQTTnet.Exceptions;
 using MQTTnet.Packets;
 using MQTTnet.Serializer;
 using System;
@@ -83,7 +84,7 @@ namespace MQTTnet.AspNetCore
                         }
                         else if (readResult.IsCompleted)
                         {
-                            break;
+                            throw new MqttCommunicationException("Connection Aborted");
                         }
                     }
                     finally

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

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>netcoreapp2.1</TargetFramework>
@@ -7,9 +7,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.7.0" />
-    <PackageReference Include="MSTest.TestAdapter" Version="1.2.1" />
-    <PackageReference Include="MSTest.TestFramework" Version="1.2.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.8.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="1.3.2" />
+    <PackageReference Include="MSTest.TestFramework" Version="1.3.2" />
   </ItemGroup>
 
   <ItemGroup>

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

@@ -0,0 +1,22 @@
+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
+        }
+    }
+}

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

@@ -0,0 +1,16 @@
+using System.IO.Pipelines;
+
+namespace MQTTnet.AspNetCore.Tests.Mockups
+{
+    public class DuplexPipeMockup : IDuplexPipe
+    {
+        PipeReader IDuplexPipe.Input => Receive.Reader;
+
+        PipeWriter IDuplexPipe.Output => Send.Writer;
+
+
+        public Pipe Receive { get; set; } = new Pipe();
+
+        public Pipe Send { get; set; } = new Pipe();
+    }
+}

Tests/MQTTnet.AspNetCore.Tests/MqttConnectionContextTest.cs

@@ -0,0 +1,29 @@
+using Microsoft.AspNetCore.Connections;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.AspNetCore.Tests.Mockups;
+using MQTTnet.Exceptions;
+using MQTTnet.Serializer;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MQTTnet.AspNetCore.Tests
+{
+    [TestClass]
+    public class MqttConnectionContextTest
+    {
+        [TestMethod]
+        public async Task TestReceivePacketAsyncThrowsWhenReaderCompleted()
+        {
+            var serializer = new MqttPacketSerializer {};
+            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(TimeSpan.FromSeconds(1), CancellationToken.None));
+        }
+    }
+}

Tests/MQTTnet.Core.Tests/MQTTnet.Core.Tests.csproj

@@ -9,7 +9,7 @@
   <ItemGroup>
     <PackageReference Include="MSTest.TestAdapter" Version="1.3.2" />
     <PackageReference Include="MSTest.TestFramework" Version="1.3.2" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.7.2" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.8.0" />
   </ItemGroup>
 
   <ItemGroup>