Merge pull request #338 from rabbitmq/rabbitmq-dotnet-client-337

Dispose of sockets that failed to connect

Author: kjnilsson

projects/client/RabbitMQ.Client/RabbitMQ.Client.csproj

@@ -61,6 +61,7 @@
     <PackageReference Include="System.Net.Sockets" Version="4.3.0" />
     <PackageReference Include="System.Reflection.Extensions" Version="4.3.0" />
     <PackageReference Include="System.Reflection.TypeExtensions" Version="4.3.0" />
+    <PackageReference Include="System.Runtime" Version="4.3.0" />
     <PackageReference Include="System.Runtime.Extensions" Version="4.3.0" />
     <PackageReference Include="System.Text.RegularExpressions" Version="4.3.0" />
     <PackageReference Include="System.Threading" Version="4.3.0" />

projects/client/RabbitMQ.Client/src/client/api/ITcpClient.cs

@@ -10,7 +10,7 @@ namespace RabbitMQ.Client
     /// Wrapper interface for standard TCP-client. Provides socket for socket frame handler class.
     /// </summary>
     /// <remarks>Contains all methods that are currenty in use in rabbitmq client.</remarks>
-    public interface ITcpClient
+    public interface ITcpClient : IDisposable
     {
         bool Connected { get; }
 

projects/client/RabbitMQ.Client/src/client/impl/SocketFrameHandler.cs

@@ -84,29 +84,20 @@ public SocketFrameHandler(AmqpTcpEndpoint endpoint,
             int connectionTimeout, int readTimeout, int writeTimeout)
         {
             Endpoint = endpoint;
-            m_socket = null;
-            if (Socket.OSSupportsIPv6 && endpoint.AddressFamily != AddressFamily.InterNetwork)
+
+            if (ShouldTryIPv6(endpoint))
             {
-                try
-                {
-                    m_socket = socketFactory(AddressFamily.InterNetworkV6);
-                    Connect(m_socket, endpoint, connectionTimeout);
-                }
-                catch (ConnectFailureException) // could not connect using IPv6
-                {
-                    m_socket = null;
-                }
-                // Mono might raise a SocketException when using IPv4 addresses on
-                // an OS that supports IPv6
-                catch (SocketException)
+                try {
+                    m_socket = ConnectUsingIPv6(endpoint, socketFactory, connectionTimeout);
+                } catch (ConnectFailureException)
                 {
                     m_socket = null;
                 }
             }
+
             if (m_socket == null && endpoint.AddressFamily != AddressFamily.InterNetworkV6)
             {
-                m_socket = socketFactory(AddressFamily.InterNetwork);
-                Connect(m_socket, endpoint, connectionTimeout);
+                m_socket = ConnectUsingIPv4(endpoint, socketFactory, connectionTimeout);
             }
 
             Stream netstream = m_socket.GetStream();
@@ -164,12 +155,10 @@ public int ReadTimeout
                         m_socket.ReceiveTimeout = value;
                     }
                 }
-#pragma warning disable 0168
-                catch (SocketException _)
+                catch (SocketException)
                 {
                     // means that the socket is already closed
                 }
-#pragma warning restore 0168
             }
         }
 
@@ -190,13 +179,6 @@ public void Close()
                 {
                     try
                     {
-                        try
-                        {
-
-                        } catch (ArgumentException)
-                        {
-                            // ignore, we are closing anyway
-                        };
                         m_socket.Close();
                     }
                     catch (Exception)
@@ -273,14 +255,48 @@ public void Flush()
             }
         }
 
-        private void Connect(ITcpClient socket, AmqpTcpEndpoint endpoint, int timeout)
+        private bool ShouldTryIPv6(AmqpTcpEndpoint endpoint)
+        {
+            return (Socket.OSSupportsIPv6 && endpoint.AddressFamily != AddressFamily.InterNetwork);
+        }
+
+        private ITcpClient ConnectUsingIPv6(AmqpTcpEndpoint endpoint,
+                                            Func<AddressFamily, ITcpClient> socketFactory,
+                                            int timeout)
+        {
+            return ConnectUsingAddressFamily(endpoint, socketFactory, timeout, AddressFamily.InterNetworkV6);
+        }
+
+        private ITcpClient ConnectUsingIPv4(AmqpTcpEndpoint endpoint,
+                                            Func<AddressFamily, ITcpClient> socketFactory,
+                                            int timeout)
+        {
+            return ConnectUsingAddressFamily(endpoint, socketFactory, timeout, AddressFamily.InterNetwork);
+        }
+
+        private ITcpClient ConnectUsingAddressFamily(AmqpTcpEndpoint endpoint,
+                                                    Func<AddressFamily, ITcpClient> socketFactory,
+                                                    int timeout, AddressFamily family)
+        {
+            ITcpClient socket = socketFactory(family);
+            try {
+                ConnectOrFail(socket, endpoint, timeout);
+                return socket;
+            } catch (ConnectFailureException e) {
+                socket.Dispose();
+                throw e;
+            }
+        }
+
+        private void ConnectOrFail(ITcpClient socket, AmqpTcpEndpoint endpoint, int timeout)
         {
             try
             {
                 socket.ConnectAsync(endpoint.HostName, endpoint.Port)
                             .TimeoutAfter(timeout)
                             .ConfigureAwait(false)
-                            .GetAwaiter()//this ensures exceptions aren't wrapped in an AggregateException
+                            // this ensures exceptions aren't wrapped in an AggregateException
+                            .GetAwaiter()
                             .GetResult();
             }
             catch (ArgumentException e)

projects/client/RabbitMQ.Client/src/client/impl/TcpClientAdapter.cs

@@ -41,8 +41,15 @@ public virtual async Task ConnectAsync(string host, int port)
 
         public virtual void Close()
         {
-            if(sock != null)
+            this.Dispose();
+        }
+
+        public virtual void Dispose()
+        {
+            if (sock != null)
+            {
                 sock.Dispose();
+            }
             sock = null;
         }