Revert "Revert "fixed edge event message link changes""

This reverts commit 2931277.

Author: davilu

iothub/device/src/Transport/Amqp/AmqpUnit.cs

@@ -269,7 +269,8 @@ public async Task<AmqpIoTOutcome> DisposeMessageAsync(string lockToken, AmqpIoTD
             {
                 await EnsureMessageReceivingLinkAsync(timeout).ConfigureAwait(false);
                 disposeOutcome = await _messageReceivingLink.DisposeMessageAsync(lockToken, AmqpIoTResultAdapter.GetResult(disposeAction), timeout).ConfigureAwait(false);
-            } else
+            }
+            else
             {
                 await EnableEventReceiveAsync(timeout).ConfigureAwait(false);
                 disposeOutcome = await _eventReceivingLink.DisposeMessageAsync(lockToken, AmqpIoTResultAdapter.GetResult(disposeAction), timeout).ConfigureAwait(false);
@@ -281,14 +282,14 @@ public async Task<AmqpIoTOutcome> DisposeMessageAsync(string lockToken, AmqpIoTD
         #endregion
 
         #region Event
-        private async Task EnsureEventReceivingLinkAsync(TimeSpan timeout)
+        public async Task EnableEventReceiveAsync(TimeSpan timeout)
         {
             if (_closed)
             {
                 throw new IotHubException("Device is now offline.", false);
             }
 
-            if (Logging.IsEnabled) Logging.Enter(this, timeout, $"{nameof(EnsureEventReceivingLinkAsync)}");
+            if (Logging.IsEnabled) Logging.Enter(this, timeout, $"{nameof(EnableEventReceiveAsync)}");
             AmqpIoTSession amqpIoTSession = await EnsureSessionAsync(timeout).ConfigureAwait(false);
             bool gain = await _eventReceivingLinkLock.WaitAsync(timeout).ConfigureAwait(false);
             if (!gain)
@@ -301,30 +302,16 @@ private async Task EnsureEventReceivingLinkAsync(TimeSpan timeout)
                 if (_eventReceivingLink == null || _eventReceivingLink.IsClosing())
                 {
                     _eventReceivingLink = await amqpIoTSession.OpenEventsReceiverLinkAsync(_deviceIdentity, timeout).ConfigureAwait(false);
-
                     _eventReceivingLink.Closed += (obj, arg) => {
                         amqpIoTSession.SafeClose();
                     };
-                    if (Logging.IsEnabled) Logging.Associate(this, this, _eventReceivingLink, $"{nameof(EnsureEventReceivingLinkAsync)}");
+                    _eventReceivingLink.RegisterEventListener(OnEventsReceived);
+                    if (Logging.IsEnabled) Logging.Associate(this, this, _eventReceivingLink, $"{nameof(EnableEventReceiveAsync)}");
                 }
             }
             finally
             {
                 _eventReceivingLinkLock.Release();
-                if (Logging.IsEnabled) Logging.Exit(this, timeout, $"{nameof(EnsureEventReceivingLinkAsync)}");
-            }
-        }
-
-        public async Task EnableEventReceiveAsync(TimeSpan timeout)
-        {
-            if (Logging.IsEnabled) Logging.Enter(this, timeout, $"{nameof(EnableEventReceiveAsync)}");
-            try
-            {
-                await EnsureEventReceivingLinkAsync(timeout).ConfigureAwait(false);
-                _eventReceivingLink.RegisterEventListener(OnEventsReceived);
-            }
-            finally
-            {
                 if (Logging.IsEnabled) Logging.Exit(this, timeout, $"{nameof(EnableEventReceiveAsync)}");
             }
         }