fix: RpcQueueContainer deregister from NetworkUpdateManager (#453)

* fix: deregistration fix

This fixes the issue with the RpcQueueContainer not deregistering itself from the NetworkUpdateManager upon shutdown of the NetworkingManager.

* refactor: Removing comment

Removing a comment that doesn't need to be there.

* refactor: code clarity

@jeffreyrainy suggested that the OnExiting method was confusing and it didn't make sense having more than one method to call in order to handle cleaning up and deregistering from the network update loop.
These changes refactors the method used to handle shutting down.

Author: NoelStephensUnity

com.unity.multiplayer.mlapi/Runtime/Core/NetworkingManager.cs

@@ -670,7 +670,7 @@ private void OnDestroy()
         {
             OnNetworkLoopSystemRemove();
             //NSS: This is ok to leave this check here
-            rpcQueueContainer?.OnExiting();
+            rpcQueueContainer?.Shutdown();
 
             if (Singleton != null && Singleton == this)
             {
@@ -693,7 +693,8 @@ private void Shutdown()
             SpawnManager.DestroyNonSceneObjects();
             SpawnManager.ServerResetShudownStateForSceneObjects();
 
-            if (NetworkConfig != null && NetworkConfig.NetworkTransport != null) //The Transport is set during Init time, thus it is possible for the Transport to be null
+            //The Transport is set during Init time, thus it is possible for the Transport to be null
+            if (NetworkConfig != null && NetworkConfig.NetworkTransport != null)
                 NetworkConfig.NetworkTransport.Shutdown();
 
             if (rpcQueueContainer != null)

com.unity.multiplayer.mlapi/Runtime/Messaging/RPCQueue/RPCQueueContainer.cs

@@ -649,8 +649,9 @@ public bool IsTesting()
             return m_IsTestingEnabled;
         }
 
+
         /// <summary>
-        /// Clears all declared parameters
+        /// Clears the stream indices and frames process properties
         /// </summary>
         private void ClearParameters()
         {
@@ -661,10 +662,12 @@ private void ClearParameters()
         }
 
         /// <summary>
-        /// OnExiting
-        /// Called upon exiting to assure any last messages are delivered.
+        /// Shutdown
+        /// Flushes the internal messages
+        /// Removes itself from the network update loop
+        /// Disposes readers, writers, clears the queue history, and resets any parameters
         /// </summary>
-        public void OnExiting()
+        public void Shutdown()
         {
             //We need to make sure all internal messages (i.e. object destroy) are sent
             rpcQueueProcessing.InternalMessagesSendAndFlush();
@@ -675,14 +678,8 @@ public void OnExiting()
                 //Remove ourself from the network loop update system
                 OnNetworkLoopSystemRemove();
             }
-        }
 
-        /// <summary>
-        /// There might be a case where we want to make this class non-static and in that case we would replace this with Dispose and add the IDisposable interface
-        /// For now, this should be called upon shutdown
-        /// </summary>
-        public void Shutdown()
-        {
+            //Dispose of any readers and writers
             foreach (KeyValuePair<QueueHistoryFrame.QueueFrameType, Dictionary<int, Dictionary<NetworkUpdateManager.NetworkUpdateStages, QueueHistoryFrame>>> queueHistorySection in QueueHistory)
             {
                 foreach (KeyValuePair<int, Dictionary<NetworkUpdateManager.NetworkUpdateStages, QueueHistoryFrame>> queueHistoryItemByStage in queueHistorySection.Value)
@@ -696,6 +693,7 @@ public void Shutdown()
                 }
             }
 
+            //Clear history and parameters
             QueueHistory.Clear();
 
             ClearParameters();