[bug] bundle.LoadAssetAsync can complete just inplace

workaround:
in BundledAssetProvider.cs Start(...)

Code (CSharp):

1.                     //**addressables: bugfix: possible to be completed just here and provideHandle became invalid then
2.                     provideHandle.SetProgressCallback(ProgressCallback);
3.                    
4.                     m_RequestOperation.completed += ActionComplete;
5.                     //provideHandle.SetProgressCallback(ProgressCallback);

and in ProviderOperation.cs Progress get

Code (CSharp):

1.                 if (m_GetProgressCallback == null)
2.                     //return 0.5f;
3.                     //**addressables: bugfix: return full completeness for succeed operation after ProviderCompleted (m_NeedsRelease contains status)
4.                     return m_NeedsRelease ? 1.0f: 0.0f;

 

missed changes in AssetBundleProvider.cs Start(...):

Code (CSharp):

1.             //**addressables: bugfix: setup before BeginOperation - read details below
2.             provideHandle.SetProgressCallback(PercentComplete);
3.            
4.             BeginOperation();
5.            
6.             //**addressables: bugfix: if m_RequestOperation.completed is called just inside BeginOperation, then provideHandle is completed (version changed)
7.             //    and SetProgressCallback throws exception "The ProvideHandle is invalid. After the handle has been completed, it can no longer be used"
8.             //    and correctly completed operation (either LoadFromFileAsync or SendWebRequest) fails!
9.             //provideHandle.SetProgressCallback(PercentComplete);

 

have you make a bug report?

 

Sorry, no. Good bug report requires to create sample test-case.. a lot of time to waste after it's already fixed.
All such bugs I repair by myself in big project where it was found and at least write about them here =).

 

I appreciate the bug info and fix, but could you please add a little more context so we are sure to not misunderstand what you are fixing? What exact scenario is broken? "[bug] bundle.LoadAssetAsync can complete just inplace" Does that mean it can in theory, but it isn't now, so the fix makes it do that? Or it can now, but it shouldn't, so the fix stops it?

 

It still really happens, just checked in the simple sample. Depends on the speed of UnityWebRequestAssetBundle.
To reproduce - make two LoadAssetAsync in a row:

Code (CSharp):

1.     private IEnumerator Start()
2.     {
3.         yield return Addressables.LoadAssetAsync<GameObject>("Canvas");
4.         yield return Addressables.LoadAssetAsync<GameObject>("Canvas");
5.     }
6.  

To emulate "fast" request and reproduce repeat with absolute probability - put

Thread.Sleep(1000);

in AssetBundleProvider.cs after

m_RequestOperation = req.SendWebRequest();

:

Code (CSharp):

1.                 m_RequestOperation = req.SendWebRequest();
2.                 Thread.Sleep(1000);
3.                 m_RequestOperation.completed += WebRequestOperationCompleted;
4.  

In the attach - the simplest project: open Scenes/SampleScene.unity, switch to "Packed Mode", "Build Player Content", "Play". Result:

Code (CSharp):

1. Exception: Attempting to use an invalid operation handle
2. UnityEngine.ResourceManagement.AsyncOperations.AsyncOperationHandle.get_InternalOp () (at Library/PackageCache/com.unity.addressables@1.1.9/Runtime/ResourceManager/AsyncOperations/AsyncOperationHandle.cs:258)
3. UnityEngine.ResourceManagement.AsyncOperations.AsyncOperationHandle.get_Status () (at Library/PackageCache/com.unity.addressables@1.1.9/Runtime/ResourceManager/AsyncOperations/AsyncOperationHandle.cs:322)
4. UnityEngine.ResourceManagement.AsyncOperations.GroupOperation.CompleteIfDependenciesComplete () (at Library/PackageCache/com.unity.addressables@1.1.9/Runtime/ResourceManager/AsyncOperations/GroupOperation.cs:56)
5. UnityEngine.ResourceManagement.AsyncOperations.GroupOperation.OnOperationCompleted (UnityEngine.ResourceManagement.AsyncOperations.AsyncOperationHandle op) (at Library/PackageCache/com.unity.addressables@1.1.9/Runtime/ResourceManager/AsyncOperations/GroupOperation.cs:102)
6. DelegateList`1[T].Invoke (T res) (at Library/PackageCache/com.unity.addressables@1.1.9/Runtime/ResourceManager/Util/DelegateList.cs:69)
7. UnityEngine.Debug:LogException(Exception)
8. DelegateList`1:Invoke(AsyncOperationHandle) (at Library/PackageCache/com.unity.addressables@1.1.9/Runtime/ResourceManager/Util/DelegateList.cs:73)
9. UnityEngine.AsyncOperation:InvokeCompletionEvent()
10.  

 

Ah, I see. The issue is that the op can finish too quickly. Have you tried this with 1.1.9? A too-fast-op was what was also causing failed downloads to remain in the op cache forever. This note from the changelog:
Fixed issue where failed async operations weren't getting released from the async operation cache

Not sure if that fix will solve for what you posted about, but it may. If not, we definitely want to get it cleaned up.

 

Yes, the sample I've tried was on Unity 2019.2.1f1 with addressables 1.1.9.
To surely reproduce it - just put

Thread.Sleep(1000);

after

m_RequestOperation = req.SendWebRequest();

in AssetBundleProvider.cs

 

Can confirm this too. Addressables version 1.1.9, Unity 2018.4.6f1.

I had this issue running on WebGL and nik_d's workaround removed my "ProvideHandle invalid" exceptions. Without the fix first asset loads would be ok but a second load op after Release would throw exceptions. If I understood docs correctly the asset/bundle is not actually unloaded on Release (even if ref count goes to 0). I guess then the second "load" would just fetch the asset from memory which would then be 'too-fast' and cause the ProvideHandle to be invalid?

 

Thanks for letting us know, we'll get that cleaned up.

 

Still bugged in 1.2.4

 

I get that you got a hold of this, no bug report or anything needed?

I also encountered this in current (1.2.4), and nik_d's fix solved it (thanks a ton for sharing!)

In my case, it is with WebGL, I think when the asset is already in browser cache (local storage i guess). First time loading worked. Then when e.g. opening the app again, it failed. After clearing local storage, worked again. Once. I guess the op is sync in the browser in the sense that it succeeds immediately when the data is already in cache.

 

I don't recommend using Addressables in WebGL in production. For me it gave very unpredictable results. Everything worked fine and suddenly after one build project started to eat huge amounts of memory and to crash the browser.

 

Sorry if answering an old thread is inappropriate, but I found this one on google and nik_d's workaround was still needed for me in Addressables version 1.10.

 

@DavidUnity3d I'm still seeing "Exception: Attempting to use an invalid operation handle" on BundledAssetProvider:89 where an async op with an outdated version is accessed by an async op handle.

I'm running Unity 2019.4.15 and Addressables 1.16.13

 

If anybody else like me is encountering the "Attempting to use an invalid operation handle" issue even with recent Addressables versions, make sure Addressables.Release(handle) is not called twice with the same handle somewhere in your code.

In my case, it was causing the refcount to decrease to zero while other handles were using it.