Merge branch 'Fix-high-CPU-usage'

.github/workflows/ReleaseNotes.md

@@ -3,4 +3,5 @@
 * [ManagedClient] The managed client now sends the entire topic filter including new MQTTv5 properties when subscribing.
 * [Server] Fixed reporting of _MaximumQoS_ in _ConnAck_ packet (MQTTv5 only) (#1442).
 * [Server] Fix cross thread issue in session message storage for QoS 1 and 2.
-* [Server] The event _ClientSubscribedTopicAsync_ is now fired after the subscription is completely processed internally (#1435).
+* [Server] The event _ClientSubscribedTopicAsync_ is now fired after the subscription is completely processed internally (#1435).
+* [Server] Improved CPU usage on lower end machines (#788).

Source/MQTTnet/Server/Internal/MqttClient.cs

@@ -188,6 +188,8 @@ namespace MQTTnet.Server
                 // own exception in the reading loop!
                 while (!cancellationToken.IsCancellationRequested)
                 {
+                    await Task.Yield();
+                    
                     var packet = await ChannelAdapter.ReceivePacketAsync(cancellationToken).ConfigureAwait(false);
                     if (packet == null)
                     {
@@ -315,6 +317,10 @@ namespace MQTTnet.Server
                     {
                         packetBusItem.MarkAsFailed(exception);
                     }
+                    finally
+                    {
+                        await Task.Yield();
+                    }
                 }
             }
             catch (OperationCanceledException)