Question NotSupportedException: Control count per binding cannot exceed byte.MaxValue=255

Whenever I run my Play Tests I eventually receive an exception during their execution:

Once this error starts happening, it doesn't go away until I restart the Unity Editor. I think I am either using my InputActionAsset incorrectly or something isn't getting cleaned up as part of the test teardown or both. I'm not sure exactly what the issue is and I've dug into this a bit so far so I figured I'd reach out here to see if anyone else has run into this error before. I've included a stack trace below as well.

Code (CSharp):

1. UnityEngine.InputSystem.InputActionState+BindingState.set_controlCount (System.Int32 value) (at Library/PackageCache/com.unity.inputsystem@1.0.2/InputSystem/Actions/InputActionState.cs:2321)
2. UnityEngine.InputSystem.InputBindingResolver.AddActionMap (UnityEngine.InputSystem.InputActionMap map) (at Library/PackageCache/com.unity.inputsystem@1.0.2/InputSystem/Actions/InputBindingResolver.cs:369)
3. UnityEngine.InputSystem.InputActionAsset:Enable()
4. Game.InputScheme:Enable() (at Assets/Scripts/InputScheme.cs:1160)
5. Game.PlayerInput:OnEnable() (at Assets/Scripts/PlayerInput.cs:38)
6. UnityEngine.Object:Instantiate(GameObject, Vector3, Quaternion)
7. Game.Utilities.PlayerResolver:CreatePlayer(Vector2) (at Assets/Scripts/Utilities/PlayerUtility.cs:41)
8. Game.Utilities.PlayerUtility:CreatePlayer(Vector2) (at Assets/Scripts/Utilities/PlayerUtility.cs:134)
9. Game.<SpawnPlayer>d__15:MoveNext() (at Assets/Scripts/PlayerSpawner.cs:92)
10. UnityEngine.MonoBehaviour:StartCoroutine(IEnumerator)
11. Game.PlayerSpawner:PrepareToSpawnPlayer() (at Assets/Scripts/PlayerSpawner.cs:80)
12. Game.PlayerSpawner:OnLevelActivate(GameLevel) (at Assets/Scripts/PlayerSpawner.cs:66)
13. Game.GameObjects.GameLevel:Activate() (at Assets/Scripts/GameObjects/GameLevel.cs:163)
14. GameEditor.Tests.Integration.TestHelpers.LevelHelper:ActivateLevel(GameLevel) (at Assets/Tests/Editor/Integration/TestHelpers/LevelHelper.cs:9)
15. GameEditor.Tests.Integration.AI.<WhenEnemyIsSpawned_ItWaitsInIdle>d__0:MoveNext() (at Assets/Tests/Editor/Integration/AI/EnemyAIBasicBehaviours.cs:45)
16. UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)

 

I just started using the InputSystem TestFramework and I am getting the same error in my PlayMode tests.

Unity version 2020.3.24f1.

NotSupportedException: Control count per binding cannot exceed byte.MaxValue=255

UnityEngine.InputSystem.InputActionState+BindingState.set_controlCount (System.Int32 value) (at Library/PackageCache/com.unity.inputsystem@1.2.0/InputSystem/Actions/InputActionState.cs:2828)

UnityEngine.InputSystem.InputBindingResolver.AddActionMap (UnityEngine.InputSystem.InputActionMap map) (at Library/PackageCache/com.unity.inputsystem@1.2.0/InputSystem/Actions/InputBindingResolver.cs:383)

UnityEngine.InputSystem.UI.InputSystemUIInputModule:OnEnable() (at Library/PackageCache/com.unity.inputsystem@1.2.0/InputSystem/Plugins/UI/InputSystemUIInputModule.cs:1378)

 

Here is a simple test that reproduces the problem. With a fresh start of the Unity Editor I got the error after only 30 instances of this test running.

Code (CSharp):

1.    
2.     // an array { 0, 1, 2, ... 260 }
3.     static int[] iteration = Enumerable.Repeat(0, 260).Select((tr, ti) => tr + ti).ToArray();  
4.  
5.     [UnityTest]
6.     public IEnumerator GamepadDoesntCleanUpProperly([ValueSource("iteration")] int dummy)
7.     {
8.         Gamepad gamepad = InputSystem.AddDevice<Gamepad>();
9.         return null;
10.     }
11.  

 

I'm using v1.0.2 of the input system package. This seems to be a bug in the input system where whenever you bind a new control using InputSystem.AddDevice<T>() it increments this counter, but never decrements it. I think i've managed to work around this by removing any bound controls in my test teardown with InputSystem.RemoveDevice<T>() but im not 100% sure this has worked. It would be nice to have what this limit is and when it gets incremented/decremented within the docs somewhere.

 

I was already on Input System 1.2.0 so I can confirm that the bug is evident under this version using my sample code above. I am also on the latest version of Test Framework, 1.1.30.

I can also confirm that the workaround that codeimpossible suggested (calling RemoveDevice in a [UnityTearDown] function) works for me.

 

Only if

InputTestFixture

is used will cleanup be performed automatically. Otherwise, a test will simply use the "live" version of the system and thus every

AddDevice

call in a test will simply keep adding devices that stick around until after the test.

When not using

InputTestFixture

, any cleanup has to be performed manually.