Improving performance of BehaviourUpdater

- Full credit to Unity-Technologies#1951

Author: davidvogelunity

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

@@ -567,6 +567,14 @@ internal void InitializeVariables()
             }
         }
 
+        internal void MarkDirty()
+        {
+            if (m_NetworkObject != null)
+            {
+                NetworkManager.BehaviourUpdater.AddForUpdate(this);
+            }
+        }
+
         internal void PreNetworkVariableWrite()
         {
             // reset our "which variables got written" data
@@ -599,11 +607,6 @@ internal void VariableUpdate(ulong targetClientId)
 
         private void NetworkVariableUpdate(ulong targetClientId, int behaviourIndex)
         {
-            if (!CouldHaveDirtyNetworkVariables())
-            {
-                return;
-            }
-
             for (int j = 0; j < m_DeliveryMappedNetworkVariableIndices.Count; j++)
             {
                 var shouldSend = false;
@@ -648,20 +651,6 @@ private void NetworkVariableUpdate(ulong targetClientId, int behaviourIndex)
             }
         }
 
-        private bool CouldHaveDirtyNetworkVariables()
-        {
-            // TODO: There should be a better way by reading one dirty variable vs. 'n'
-            for (int i = 0; i < NetworkVariableFields.Count; i++)
-            {
-                if (NetworkVariableFields[i].IsDirty())
-                {
-                    return true;
-                }
-            }
-
-            return false;
-        }
-
         internal void MarkVariablesDirty()
         {
             for (int j = 0; j < NetworkVariableFields.Count; j++)

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

@@ -5,12 +5,17 @@ namespace Unity.Netcode
 {
     public class NetworkBehaviourUpdater
     {
-        private HashSet<NetworkObject> m_Touched = new HashSet<NetworkObject>();
+        private HashSet<NetworkBehaviour> m_Touched = new HashSet<NetworkBehaviour>();
 
 #if DEVELOPMENT_BUILD || UNITY_EDITOR
         private ProfilerMarker m_NetworkBehaviourUpdate = new ProfilerMarker($"{nameof(NetworkBehaviour)}.{nameof(NetworkBehaviourUpdate)}");
 #endif
 
+        internal void AddForUpdate(NetworkBehaviour networkBehaviour)
+        {
+            m_Touched.Add(networkBehaviour);
+        }
+
         internal void NetworkBehaviourUpdate(NetworkManager networkManager)
         {
 #if DEVELOPMENT_BUILD || UNITY_EDITOR
@@ -20,33 +25,24 @@ internal void NetworkBehaviourUpdate(NetworkManager networkManager)
             {
                 if (networkManager.IsServer)
                 {
-                    m_Touched.Clear();
-                    for (int i = 0; i < networkManager.ConnectedClientsList.Count; i++)
+                    foreach (var networkBehaviour in m_Touched)
                     {
-                        var client = networkManager.ConnectedClientsList[i];
-                        var spawnedObjs = networkManager.SpawnManager.SpawnedObjectsList;
-                        m_Touched.UnionWith(spawnedObjs);
-                        foreach (var sobj in spawnedObjs)
+                        foreach (var client in networkManager.ConnectedClientsList)
                         {
-                            if (sobj.IsNetworkVisibleTo(client.ClientId))
+                            if (!networkBehaviour.HasNetworkObject || !networkBehaviour.NetworkObject.IsNetworkVisibleTo(client.ClientId))
                             {
-                                // Sync just the variables for just the objects this client sees
-                                for (int k = 0; k < sobj.ChildNetworkBehaviours.Count; k++)
-                                {
-                                    sobj.ChildNetworkBehaviours[k].VariableUpdate(client.ClientId);
-                                }
+                                continue;
                             }
+
+                            networkBehaviour.VariableUpdate(client.ClientId);
                         }
                     }
 
-                    // Now, reset all the no-longer-dirty variables
-                    foreach (var sobj in m_Touched)
+                    foreach (var networkBehaviour in m_Touched)
                     {
-                        for (int k = 0; k < sobj.ChildNetworkBehaviours.Count; k++)
-                        {
-                            sobj.ChildNetworkBehaviours[k].PostNetworkVariableWrite();
-                        }
+                        networkBehaviour.PostNetworkVariableWrite();
                     }
+                    m_Touched.Clear();
                 }
                 else
                 {

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

@@ -74,7 +74,7 @@ private static unsafe bool ValueEquals(ref T a, ref T b)
 
         private protected void Set(T value)
         {
-            m_IsDirty = true;
+            SetDirty(true);
             T previousValue = m_InternalValue;
             m_InternalValue = value;
             OnValueChanged?.Invoke(previousValue, m_InternalValue);
@@ -106,7 +106,7 @@ public override void ReadDelta(FastBufferReader reader, bool keepDirtyDelta)
 
             if (keepDirtyDelta)
             {
-                m_IsDirty = true;
+                SetDirty(true);
             }
 
             OnValueChanged?.Invoke(previousValue, m_InternalValue);

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

@@ -17,6 +17,10 @@ public abstract class NetworkVariableBase : IDisposable
         public void Initialize(NetworkBehaviour networkBehaviour)
         {
             m_NetworkBehaviour = networkBehaviour;
+            if (IsDirty() && m_NetworkBehaviour != null)
+            {
+                m_NetworkBehaviour.MarkDirty();
+            }
         }
 
         public const NetworkVariableReadPermission DefaultReadPerm = NetworkVariableReadPermission.Everyone;
@@ -30,7 +34,7 @@ protected NetworkVariableBase(
             WritePerm = writePerm;
         }
 
-        private protected bool m_IsDirty;
+        private bool m_IsDirty;
 
         /// <summary>
         /// Gets or sets the name of the network variable's instance
@@ -51,6 +55,10 @@ protected NetworkVariableBase(
         public virtual void SetDirty(bool isDirty)
         {
             m_IsDirty = isDirty;
+            if (isDirty && m_NetworkBehaviour != null)
+            {
+                m_NetworkBehaviour.MarkDirty();
+            }
         }
 
         /// <summary>