Refactor code.

Source/MQTTnet/Client/MqttClient.cs

@@ -400,7 +400,7 @@ namespace MQTTnet.Client
                 identifier = packetWithIdentifier.PacketIdentifier.Value;
             }
 
-            using (var packetAwaiter = _packetDispatcher.AddPacketAwaiter<TResponsePacket>(identifier))
+            using (var packetAwaiter = _packetDispatcher.AddAwaiter<TResponsePacket>(identifier))
             {
                 try
                 {

Source/MQTTnet/Internal/ArraySegmentExtensions.cs

@@ -1,23 +0,0 @@
-using System;
-
-namespace MQTTnet.Internal
-{
-    public static class ArraySegmentExtensions
-    {
-        public static byte[] ToArray(this ArraySegment<byte> source)
-        {
-            if (source.Array == null)
-            {
-                return null;
-            }
-
-            var buffer = new byte[source.Count];
-            if (buffer.Length > 0)
-            {
-                Array.Copy(source.Array, source.Offset, buffer, 0, buffer.Length);
-            }
-
-            return buffer;
-        }
-    }
-}

Source/MQTTnet/MQTTnet.csproj

@@ -54,7 +54,7 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)'=='uap10.0'">
-    <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform" Version="6.2.8" />
+    <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform" Version="6.2.10" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)'=='net452'">
@@ -62,9 +62,5 @@
 
   <ItemGroup Condition="'$(TargetFramework)'=='net461'">
   </ItemGroup>
-
-  <ItemGroup>
-    <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform" Version="6.2.10" />
-  </ItemGroup>
   
 </Project>

Source/MQTTnet/PacketDispatcher/IMqttPacketAwaiter.cs

@@ -1,5 +1,5 @@
-using System;
+using MQTTnet.Packets;
-using MQTTnet.Packets;
+using System;
 
 namespace MQTTnet.PacketDispatcher
 {

Source/MQTTnet/PacketDispatcher/MqttPacketAwaiter.cs

@@ -1,5 +1,4 @@
 using MQTTnet.Exceptions;
-using MQTTnet.Internal;
 using MQTTnet.Packets;
 using System;
 using System.Threading;
@@ -7,11 +6,11 @@ using System.Threading.Tasks;
 
 namespace MQTTnet.PacketDispatcher
 {
-    public sealed class MqttPacketAwaiter<TPacket> : Disposable, IMqttPacketAwaiter where TPacket : MqttBasePacket
+    public sealed class MqttPacketAwaiter<TPacket> : IMqttPacketAwaiter where TPacket : MqttBasePacket
     {
-        private readonly TaskCompletionSource<MqttBasePacket> _taskCompletionSource;
+        readonly TaskCompletionSource<MqttBasePacket> _taskCompletionSource;
-        private readonly ushort? _packetIdentifier;
+        readonly ushort? _packetIdentifier;
-        private readonly MqttPacketDispatcher _owningPacketDispatcher;
+        readonly MqttPacketDispatcher _owningPacketDispatcher;
 
         public MqttPacketAwaiter(ushort? packetIdentifier, MqttPacketDispatcher owningPacketDispatcher)
         {
@@ -39,7 +38,6 @@ namespace MQTTnet.PacketDispatcher
         {
             if (packet == null) throw new ArgumentNullException(nameof(packet));
 
-
 #if NET452
             // To prevent deadlocks it is required to call the _TrySetResult_ method
             // from a new thread because the awaiting code will not(!) be executed in
@@ -81,14 +79,9 @@ namespace MQTTnet.PacketDispatcher
 #endif
         }
 
-        protected override void Dispose(bool disposing)
+        public void Dispose()
         {
-            if (disposing)
+            _owningPacketDispatcher.RemoveAwaiter<TPacket>(_packetIdentifier);
-            {
-                _owningPacketDispatcher.RemovePacketAwaiter<TPacket>(_packetIdentifier);
-            }
-
-            base.Dispose(disposing);
         }
     }
 }

Source/MQTTnet/PacketDispatcher/MqttPacketDispatcher.cs

@@ -1,22 +1,22 @@
-using System;
-using System.Collections.Concurrent;
 using MQTTnet.Exceptions;
 using MQTTnet.Packets;
+using System;
+using System.Collections.Concurrent;
 
 namespace MQTTnet.PacketDispatcher
 {
-    public class MqttPacketDispatcher
+    public sealed class MqttPacketDispatcher
     {
-        private readonly ConcurrentDictionary<Tuple<ushort, Type>, IMqttPacketAwaiter> _packetAwaiters = new ConcurrentDictionary<Tuple<ushort, Type>, IMqttPacketAwaiter>();
+        readonly ConcurrentDictionary<Tuple<ushort, Type>, IMqttPacketAwaiter> _awaiters = new ConcurrentDictionary<Tuple<ushort, Type>, IMqttPacketAwaiter>();
 
         public void Dispatch(Exception exception)
         {
-            foreach (var awaiter in _packetAwaiters)
+            foreach (var awaiter in _awaiters)
             {
                 awaiter.Value.Fail(exception);
             }
 
-            _packetAwaiters.Clear();
+            _awaiters.Clear();
         }
 
         public void Dispatch(MqttBasePacket packet)
@@ -25,7 +25,7 @@ namespace MQTTnet.PacketDispatcher
 
             if (packet is MqttDisconnectPacket disconnectPacket)
             {
-                foreach (var packetAwaiter in _packetAwaiters)
+                foreach (var packetAwaiter in _awaiters)
                 {
                     packetAwaiter.Value.Fail(new MqttUnexpectedDisconnectReceivedException(disconnectPacket));
                 }
@@ -42,7 +42,7 @@ namespace MQTTnet.PacketDispatcher
             var type = packet.GetType();
             var key = new Tuple<ushort, Type>(identifier, type);
 
-            if (_packetAwaiters.TryRemove(key, out var awaiter))
+            if (_awaiters.TryRemove(key, out var awaiter))
             {
                 awaiter.Complete(packet);
                 return;
@@ -53,15 +53,15 @@ namespace MQTTnet.PacketDispatcher
 
         public void Reset()
         {
-            foreach (var awaiter in _packetAwaiters)
+            foreach (var awaiter in _awaiters)
             {
-                 awaiter.Value.Cancel();
+                awaiter.Value.Cancel();
             }
 
-            _packetAwaiters.Clear();
+            _awaiters.Clear();
         }
 
-        public MqttPacketAwaiter<TResponsePacket> AddPacketAwaiter<TResponsePacket>(ushort? identifier) where TResponsePacket : MqttBasePacket
+        public MqttPacketAwaiter<TResponsePacket> AddAwaiter<TResponsePacket>(ushort? identifier) where TResponsePacket : MqttBasePacket
         {
             if (!identifier.HasValue)
             {
@@ -71,7 +71,7 @@ namespace MQTTnet.PacketDispatcher
             var awaiter = new MqttPacketAwaiter<TResponsePacket>(identifier, this);
 
             var key = new Tuple<ushort, Type>(identifier.Value, typeof(TResponsePacket));
-            if (!_packetAwaiters.TryAdd(key, awaiter))
+            if (!_awaiters.TryAdd(key, awaiter))
             {
                 throw new InvalidOperationException($"The packet dispatcher already has an awaiter for packet of type '{key.Item2.Name}' with identifier {key.Item1}.");
             }
@@ -79,7 +79,7 @@ namespace MQTTnet.PacketDispatcher
             return awaiter;
         }
 
-        public void RemovePacketAwaiter<TResponsePacket>(ushort? identifier) where TResponsePacket : MqttBasePacket
+        public void RemoveAwaiter<TResponsePacket>(ushort? identifier) where TResponsePacket : MqttBasePacket
         {
             if (!identifier.HasValue)
             {
@@ -87,7 +87,7 @@ namespace MQTTnet.PacketDispatcher
             }
 
             var key = new Tuple<ushort, Type>(identifier.Value, typeof(TResponsePacket));
-            _packetAwaiters.TryRemove(key, out _);
+            _awaiters.TryRemove(key, out _);
         }
     }
 }

Source/MQTTnet/Server/MqttClientConnection.cs

@@ -430,14 +430,14 @@ namespace MQTTnet.Server
                     }
                     else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
                     {
-                        var awaiter = _packetDispatcher.AddPacketAwaiter<MqttPubAckPacket>(publishPacket.PacketIdentifier);
+                        var awaiter = _packetDispatcher.AddAwaiter<MqttPubAckPacket>(publishPacket.PacketIdentifier);
                         await SendAsync(publishPacket).ConfigureAwait(false);
                         await awaiter.WaitOneAsync(_serverOptions.DefaultCommunicationTimeout).ConfigureAwait(false);
                     }
                     else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
                     {
-                        using (var awaiter1 = _packetDispatcher.AddPacketAwaiter<MqttPubRecPacket>(publishPacket.PacketIdentifier))
+                        using (var awaiter1 = _packetDispatcher.AddAwaiter<MqttPubRecPacket>(publishPacket.PacketIdentifier))
-                        using (var awaiter2 = _packetDispatcher.AddPacketAwaiter<MqttPubCompPacket>(publishPacket.PacketIdentifier))
+                        using (var awaiter2 = _packetDispatcher.AddAwaiter<MqttPubCompPacket>(publishPacket.PacketIdentifier))
                         {
                             await SendAsync(publishPacket).ConfigureAwait(false);
                             await awaiter1.WaitOneAsync(_serverOptions.DefaultCommunicationTimeout).ConfigureAwait(false);

Tests/MQTTnet.Core.Tests/MqttClient_Tests.cs

@@ -36,7 +36,7 @@ namespace MQTTnet.Tests
         public async Task Connect_To_Invalid_Server_Port_Not_Opened()
         {
             var client = new MqttFactory().CreateMqttClient();
-            await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", 12345).WithCommunicationTimeout(TimeSpan.FromSeconds(2)).Build());
+            await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", 12345).WithCommunicationTimeout(TimeSpan.FromSeconds(5)).Build());
         }
 
         [TestMethod]
@@ -115,7 +115,13 @@ namespace MQTTnet.Tests
                     }
                 });
 
-                client2.UseApplicationMessageReceivedHandler(async c => { await client2.PublishAsync("reply", null, MqttQualityOfServiceLevel.AtLeastOnce); });
+                client2.UseApplicationMessageReceivedHandler(async c =>
+                {
+                    // Use AtMostOnce here because with QoS 1 or even QoS 2 the process waits for 
+                    // the ACK etc. The problem is that the SpinUntil below only waits until the 
+                    // flag is set. It does not wait until the client has sent the ACK
+                    await client2.PublishAsync("reply", null, MqttQualityOfServiceLevel.AtMostOnce);
+                });
 
                 await client1.PublishAsync("request", null, MqttQualityOfServiceLevel.AtLeastOnce);