FIX: Fixed a performance issue with many objects using multiple action maps [ISXB-573] (#1951)

FIX: Fixed a performance issue with many objects using multiple action maps [ISXB-573](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-573).

Author: AlexTyrer

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -25,6 +25,7 @@ however, it has to be formatted properly to pass verification tests.
 - Fixed an issue where adding a `OnScreenButton` or `OnScreenStick` to a regular GameObject would lead to exception in editor.
 - Fixed an issue where adding a `OnScreenStick` to a regular GameObject and entering play-mode would lead to exceptions being generated.
 - Fixed InputActionReference issues when domain reloads are disabled [ISXB-601](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-601), [ISXB-718](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-718), [ISXB-900](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-900)
+- Fixed a performance issue with many objects using multiple action maps [ISXB-573](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-573).
 
 ### Added
 - Added additional device information when logging the error due to exceeding the maximum number of events processed

Packages/com.unity.inputsystem/InputSystem/Actions/InputActionMap.cs

@@ -318,6 +318,7 @@ public event Action<InputAction.CallbackContext> actionTriggered
         /// </summary>
         public InputActionMap()
         {
+            s_NeedToResolveBindings = true;
         }
 
         /// <summary>
@@ -810,6 +811,7 @@ private enum Flags
         }
 
         internal static int s_DeferBindingResolution;
+        internal static bool s_NeedToResolveBindings;
 
         internal struct DeviceArray
         {
@@ -1193,6 +1195,9 @@ internal bool LazyResolveBindings(bool fullResolve)
             m_ControlsForEachAction = null;
             controlsForEachActionInitialized = false;
 
+            // Indicate that there is at least one action map that has a change
+            s_NeedToResolveBindings = true;
+
             // If we haven't had to resolve bindings yet, we can wait until when we
             // actually have to.
             if (m_State == null)
@@ -1982,6 +1987,9 @@ public void OnBeforeSerialize()
         /// </summary>
         public void OnAfterDeserialize()
         {
+            // Indicate that there is at least one action map that has a change
+            s_NeedToResolveBindings = true;
+
             m_State = null;
             m_MapIndexInState = InputActionState.kInvalidIndex;
             m_EnabledActionsCount = 0;

Packages/com.unity.inputsystem/InputSystem/Actions/InputActionState.cs

@@ -4491,23 +4491,27 @@ internal static void DeferredResolutionOfBindings()
             ++InputActionMap.s_DeferBindingResolution;
             try
             {
-                for (var i = 0; i < s_GlobalState.globalList.length; ++i)
+                if (InputActionMap.s_NeedToResolveBindings)
                 {
-                    var handle = s_GlobalState.globalList[i];
-
-                    var state = handle.IsAllocated ? (InputActionState)handle.Target : null;
-                    if (state == null)
+                    for (var i = 0; i < s_GlobalState.globalList.length; ++i)
                     {
-                        // Stale entry in the list. State has already been reclaimed by GC. Remove it.
-                        if (handle.IsAllocated)
-                            s_GlobalState.globalList[i].Free();
-                        s_GlobalState.globalList.RemoveAtWithCapacity(i);
-                        --i;
-                        continue;
-                    }
+                        var handle = s_GlobalState.globalList[i];
 
-                    for (var n = 0; n < state.totalMapCount; ++n)
-                        state.maps[n].ResolveBindingsIfNecessary();
+                        var state = handle.IsAllocated ? (InputActionState)handle.Target : null;
+                        if (state == null)
+                        {
+                            // Stale entry in the list. State has already been reclaimed by GC. Remove it.
+                            if (handle.IsAllocated)
+                                s_GlobalState.globalList[i].Free();
+                            s_GlobalState.globalList.RemoveAtWithCapacity(i);
+                            --i;
+                            continue;
+                        }
+
+                        for (var n = 0; n < state.totalMapCount; ++n)
+                            state.maps[n].ResolveBindingsIfNecessary();
+                    }
+                    InputActionMap.s_NeedToResolveBindings = false;
                 }
             }
             finally