Fix connection leaks on auto recovery

Author: mot256

projects/RabbitMQ.Client/client/impl/AutorecoveringConnection.cs

@@ -451,6 +451,24 @@ private bool TryPerformAutomaticRecovery()
             catch (Exception e)
             {
                 ESLog.Error("Exception when recovering connection. Will try again after retry interval.", e);
+
+                try
+                {
+                    /*
+                     * To prevent connection leaks on the next recovery loop,
+                     * we abort the delegated connection if it is still open.
+                     * We do not want to block the abort forever (potentially deadlocking recovery),
+                     * so we specify the same configured timeout used for connection.
+                     */
+                    if (_delegate?.IsOpen == true)
+                    {
+                        _delegate.Abort(Constants.InternalError, "FailedAutoRecovery", ShutdownInitiator.Library, _factory.RequestedConnectionTimeout);
+                    }
+                }
+                catch (Exception e2)
+                {
+                    ESLog.Warn("Exception when aborting previous auto recovery connection.", e2);
+                }
             }
 
             return false;
@@ -672,7 +690,6 @@ private void Init(IFrameHandler fh)
             lock (_eventLock)
             {
                 ConnectionShutdown += recoveryListener;
-                _recordedShutdownEventHandlers += recoveryListener;
             }
         }
 

projects/RabbitMQ.Client/client/impl/Connection.cs

@@ -116,7 +116,15 @@ public Connection(IConnectionFactory factory, bool insist, IFrameHandler frameHa
             _model0 = (ModelBase)Protocol.CreateModel(_session0);
 
             StartMainLoop(factory.UseBackgroundThreadsForIO);
-            Open(insist);
+            try
+            {
+                Open(insist);
+            }
+            catch
+            {
+                TerminateMainloop();
+                throw;
+            }
         }
 
         public Guid Id { get { return _id; } }

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

@@ -193,17 +193,18 @@ public void Close()
                     try
                     {
                         _channelWriter.Complete();
-                        _writerTask.GetAwaiter().GetResult();
+                        _writerTask?.GetAwaiter().GetResult();
                     }
-                    catch(Exception)
+                    catch
                     {
+                        // ignore, we are closing anyway
                     }
 
                     try
                     {
                         _socket.Close();
                     }
-                    catch (Exception)
+                    catch
                     {
                         // ignore, we are closing anyway
                     }