fix: networkvariablebase not being reinitialized if networkobject persists between sessions (#3217)

* fix

Back-port of  #3181 final fix.

* test

The test to validate this PR.

* update

Only log something if we have something to log.

* test

remove verbose mode.

* update

adding changelog entry

Author: NoelStephensUnity

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -12,6 +12,7 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 ### Fixed
 
+- Fixed issue where `NetworkVariableBase` derived classes were not being re-initialized if the associated `NetworkObject` instance was not destroyed and re-spawned. (#3217)
 - Fixed issue where a spawned `NetworkObject` that was registered with a prefab handler and owned by a client would invoke destroy more than once on the host-server side if the client disconnected while the `NetworkObject` was still spawned. (#3202)
 - Fixed issue where `NetworkRigidBody2D` was still using the deprecated `isKinematic` property in Unity versions 2022.3 and newer. (#3199)
 - Fixed issue where an exception was thrown when calling `NetworkManager.Shutdown` after calling `UnityTransport.Shutdown`. (#3118)

com.unity.netcode.gameobjects/Runtime/Core/NetworkBehaviour.cs

@@ -755,6 +755,13 @@ internal void InternalOnNetworkDespawn()
             {
                 Debug.LogException(e);
             }
+
+            // Deinitialize all NetworkVariables in the event the associated
+            // NetworkObject is recylced (in-scene placed or pooled).
+            for (int i = 0; i < NetworkVariableFields.Count; i++)
+            {
+                NetworkVariableFields[i].Deinitialize();
+            }
         }
 
         /// <summary>
@@ -858,6 +865,22 @@ internal void InitializeVariables()
         {
             if (m_VarInit)
             {
+                // If the primary initialization has already been done, then go ahead
+                // and re-initialize each NetworkVariable in the event it is an in-scene
+                // placed NetworkObject in an already loaded scene that has already been
+                // used within a network session =or= if this is a pooled NetworkObject
+                // that is being repurposed.
+                for (int i = 0; i < NetworkVariableFields.Count; i++)
+                {
+                    // If already initialized, then skip
+                    if (NetworkVariableFields[i].HasBeenInitialized)
+                    {
+                        continue;
+                    }
+                    NetworkVariableFields[i].Initialize(this);
+                }
+                // Exit early as we don't need to run through the rest of this initialization
+                // process
                 return;
             }
 

com.unity.netcode.gameobjects/Runtime/NetworkVariable/NetworkVariableBase.cs

@@ -34,6 +34,12 @@ public abstract class NetworkVariableBase : IDisposable
         private protected NetworkBehaviour m_NetworkBehaviour;
         private NetworkManager m_InternalNetworkManager;
 
+        // Determines if this NetworkVariable has been "initialized" to prevent initializing more than once which can happen when first
+        // instantiated and spawned. If this NetworkVariable instance is on an in-scene placed NetworkObject =or= a pooled NetworkObject
+        // that can persist between sessions and/or be recycled we need to reset the LastUpdateSent value prior to spawning otherwise
+        // this NetworkVariableBase property instance will not update until the last session time used.
+        internal bool HasBeenInitialized { get; private set; }
+
         public NetworkBehaviour GetBehaviour()
         {
             return m_NetworkBehaviour;
@@ -49,37 +55,82 @@ internal void LogWritePermissionError()
             Debug.LogError(GetWritePermissionError());
         }
 
-        private protected NetworkManager m_NetworkManager
-        {
-            get
-            {
-                if (m_InternalNetworkManager == null && m_NetworkBehaviour && m_NetworkBehaviour.NetworkObject?.NetworkManager)
-                {
-                    m_InternalNetworkManager = m_NetworkBehaviour.NetworkObject?.NetworkManager;
-                }
-                return m_InternalNetworkManager;
-            }
-        }
+        private protected NetworkManager m_NetworkManager => m_InternalNetworkManager;
 
         /// <summary>
         /// Initializes the NetworkVariable
         /// </summary>
         /// <param name="networkBehaviour">The NetworkBehaviour the NetworkVariable belongs to</param>
         public void Initialize(NetworkBehaviour networkBehaviour)
         {
-            m_InternalNetworkManager = null;
+            // If we have already been initialized, then exit early.
+            // This can happen on the very first instantiation and spawning of the associated NetworkObject
+            if (HasBeenInitialized)
+            {
+                return;
+            }
+
+            // Throw an exception if there is an invalid NetworkBehaviour parameter
+            if (!networkBehaviour)
+            {
+                throw new Exception($"[{GetType().Name}][Initialize] {nameof(NetworkBehaviour)} parameter passed in is null!");
+            }
             m_NetworkBehaviour = networkBehaviour;
-            if (m_NetworkBehaviour && m_NetworkBehaviour.NetworkObject?.NetworkManager)
+
+            // Throw an exception if there is no NetworkManager available
+            if (!m_NetworkBehaviour.NetworkManager)
             {
-                m_InternalNetworkManager = m_NetworkBehaviour.NetworkObject?.NetworkManager;
+                // Exit early if there has yet to be a NetworkManager assigned.
+                // This is ok because Initialize is invoked multiple times until
+                // it is considered "initialized".
+                return;
+            }
 
-                if (m_NetworkBehaviour.NetworkManager.NetworkTimeSystem != null)
-                {
-                    UpdateLastSentTime();
-                }
+            if (!m_NetworkBehaviour.NetworkObject)
+            {
+                // Exit early if there has yet to be a NetworkObject assigned.
+                // This is ok because Initialize is invoked multiple times until
+                // it is considered "initialized".
+                return;
             }
 
+            if (!m_NetworkBehaviour.NetworkObject.NetworkManagerOwner)
+            {
+                // Exit early if there has yet to be a NetworkManagerOwner assigned
+                // to the NetworkObject. This is ok because Initialize is invoked 
+                // multiple times until it is considered "initialized".
+                return;
+            }
+            m_InternalNetworkManager = m_NetworkBehaviour.NetworkObject.NetworkManagerOwner;
+
             OnInitialize();
+
+            // Some unit tests don't operate with a running NetworkManager.
+            // Only update the last time if there is a NetworkTimeSystem.
+            if (m_InternalNetworkManager.NetworkTimeSystem != null)
+            {
+                // Update our last sent time relative to when this was initialized
+                UpdateLastSentTime();
+
+                // At this point, this instance is considered initialized
+                HasBeenInitialized = true;
+            }
+            else if (m_InternalNetworkManager.LogLevel == LogLevel.Developer)
+            {
+                Debug.LogWarning($"[{m_NetworkBehaviour.name}][{m_NetworkBehaviour.GetType().Name}][{GetType().Name}][Initialize] {nameof(NetworkManager)} has no {nameof(NetworkTimeSystem)} assigned!");
+            }
+        }
+
+        /// <summary>
+        /// Deinitialize is invoked when a NetworkObject is despawned.
+        /// This allows for a recyled NetworkObject (in-scene or pooled)
+        /// to be properly initialized upon the next use/spawn.
+        /// </summary>
+        internal void Deinitialize()
+        {
+            // When despawned, reset the HasBeenInitialized so if the associated NetworkObject instance
+            // is recylced (i.e. in-scene placed or pooled) it will re-initialize the LastUpdateSent time.
+            HasBeenInitialized = false;
         }
 
         /// <summary>

com.unity.netcode.gameobjects/TestHelpers/Runtime/NetcodeIntegrationTest.cs

@@ -1550,8 +1550,12 @@ private void UnloadRemainingScenes()
 
         private void LogWaitForMessages()
         {
-            VerboseDebug(m_WaitForLog.ToString());
-            m_WaitForLog.Clear();
+            // If there is nothing to log, then don't log anything
+            if (m_WaitForLog.Length > 0)
+            {
+                VerboseDebug(m_WaitForLog.ToString());
+                m_WaitForLog.Clear();
+            }
         }
 
         private IEnumerator WaitForTickAndFrames(NetworkManager networkManager, int tickCount, float targetFrames)