spread dispose pattern

Source/MQTTnet/Implementations/MqttTcpChannel.cs

@@ -10,10 +10,11 @@ using System.Runtime.ExceptionServices;
 using System.Threading;
 using MQTTnet.Channel;
 using MQTTnet.Client.Options;
+using MQTTnet.Internal;
 
 namespace MQTTnet.Implementations
 {
-    public class MqttTcpChannel : IMqttChannel
+    public class MqttTcpChannel : Disposable, IMqttChannel
     {
         private readonly IMqttClientOptions _clientOptions;
         private readonly MqttClientTcpOptions _options;
@@ -94,7 +95,7 @@ namespace MQTTnet.Implementations
 
         public Task DisconnectAsync(CancellationToken cancellationToken)
         {
-            Dispose();
+            Cleanup();
             return Task.FromResult(0);
         }
 
@@ -158,7 +159,7 @@ namespace MQTTnet.Implementations
             }
         }
 
-        public void Dispose()
+        private void Cleanup()
         {
             // When the stream is disposed it will also close the socket and this will also dispose it.
             // So there is no need to dispose the socket again.
@@ -177,6 +178,15 @@ namespace MQTTnet.Implementations
             _stream = null;
         }
 
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                Cleanup();
+            }
+            base.Dispose(disposing);
+        }
+
         private bool InternalUserCertificateValidationCallback(object sender, X509Certificate x509Certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
         {
             if (_options.TlsOptions.CertificateValidationCallback != null)

Source/MQTTnet/Implementations/MqttWebSocketChannel.cs

@@ -112,7 +112,7 @@ namespace MQTTnet.Implementations
                 await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, cancellationToken).ConfigureAwait(false);
             }
 
-            Dispose();
+            Cleanup();
         }
 
         public async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
@@ -146,24 +146,29 @@ namespace MQTTnet.Implementations
         {
             if (disposing)
             {
-                _sendLock?.Dispose();
-                _sendLock = null;
-
-                try
-                {
-                    _webSocket?.Dispose();
-                }
-                catch (ObjectDisposedException)
-                {
-                }
-                finally
-                {
-                    _webSocket = null;
-                }
+                Cleanup();
             }
             base.Dispose(disposing);
         }
 
+        private void Cleanup()
+        {
+            _sendLock?.Dispose();
+            _sendLock = null;
+
+            try
+            {
+                _webSocket?.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+            }
+            finally
+            {
+                _webSocket = null;
+            }
+        }
+
         private IWebProxy CreateProxy()
         {
             if (string.IsNullOrEmpty(_options.ProxyOptions?.Address))