public async Task EnsureConnectionAsync()

in iothub/device/src/Transport/Amqp/AmqpConnectionHolder.cs [177:242]
56 lines of code
12 McCabe index (conditional complexity)

        public async Task<AmqpIotConnection> EnsureConnectionAsync(CancellationToken cancellationToken)
        {
            if (Logging.IsEnabled)
                Logging.Enter(this, nameof(EnsureConnectionAsync));

            AmqpIotConnection amqpIotConnection = null;
            IAmqpAuthenticationRefresher amqpAuthenticationRefresher = null;
            try
            {
                await _lock.WaitAsync(cancellationToken).ConfigureAwait(false);
            }
            catch (OperationCanceledException)
            {
                throw new TimeoutException();
            }

            try
            {
                if (_amqpIotConnection == null || _amqpIotConnection.IsClosing())
                {
                    if (Logging.IsEnabled)
                        Logging.Info(this, "Creating new AmqpConnection", nameof(EnsureConnectionAsync));

                    // Create AmqpConnection
                    amqpIotConnection = await _amqpIotConnector.OpenConnectionAsync(cancellationToken).ConfigureAwait(false);

                    if (_deviceIdentity.AuthenticationModel == AuthenticationModel.SasGrouped)
                    {
                        if (Logging.IsEnabled)
                            Logging.Info(this, "Creating connection wide AmqpAuthenticationRefresher", nameof(EnsureConnectionAsync));

                        amqpAuthenticationRefresher = new AmqpAuthenticationRefresher(_deviceIdentity, amqpIotConnection.GetCbsLink());
                        await amqpAuthenticationRefresher.InitLoopAsync(cancellationToken).ConfigureAwait(false);
                    }

                    _amqpIotConnection = amqpIotConnection;
                    _amqpAuthenticationRefresher = amqpAuthenticationRefresher;
                    _amqpIotConnection.Closed += OnConnectionClosed;
                    if (Logging.IsEnabled)
                        Logging.Associate(this, _amqpIotConnection, nameof(_amqpIotConnection));
                }
                else
                {
                    amqpIotConnection = _amqpIotConnection;
                }
            }
            catch (Exception ex) when (!ex.IsFatal())
            {
                if (amqpAuthenticationRefresher != null)
                {
                    await amqpAuthenticationRefresher.StopLoopAsync().ConfigureAwait(false);
                }

                amqpIotConnection?.SafeClose();
                throw;
            }
            finally
            {
                _lock.Release();
            }

            if (Logging.IsEnabled)
                Logging.Exit(this, nameof(EnsureConnectionAsync));

            return amqpIotConnection;
        }