RFR: 8368629: Texture.update sometimes invoked for a disposed Texture [v5]

[Lukasz Kostyra]

On Tue, 4 Nov 2025 14:49:56 GMT, Lukasz Kostyra <lkostyra at openjdk.org> wrote:

>> This PR fixes NPE thrown when trying to update D3D texture in some rare scenarios.
>> 
>> On more stressful cases (like the one using Canvas attached to this issue) it is possible that a D3DTexture.update() call will go through after the Resource Pool already pruned the underlying Texture's resource. This in turn caused an NPE, which propagated to higher levels and disrupted the rendering loop, causing the Canvas to not be drawn anymore. The update() call seems not to be called more than once on an already freed resource, suggesting this is some sort of rare race between the pool and the drawing code.
>> 
>> This change prevents the NPE from being thrown. I noticed no visual problems with the test even when the update() call is rejected by the newly added check. Best way to verify it is to add a log call inside added `if (!resource.isValid())` blocks when running the test, it will occasionally get printed but the test itself won't change its behavior like it does without this change.
>
> Lukasz Kostyra has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Review comments - MTLTexture: add isValid() check to update(MediaFrame)

Apologies for the delay, I got a bit consumed by D3D12 EA2 release and only now managed to get a closer look at the stack traces.

> I see this NPE (with this fix applied) when I go to more extremes with the amount of images shown

I think both of these don't directly relate to Texture.update causing problems, but the fixes for them are trivial. I filed separate issues for those and will take a closer look at them later down the line:
- https://bugs.openjdk.org/browse/JDK-8372276
- https://bugs.openjdk.org/browse/JDK-8372275


This was waiting a bit for me to go through all the NPEs and stack traces reported, but I think I addressed them all. I'll leave this PR for a bit more time and if there is no objections I will integrate it tomorrow.

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PR Comment: https://git.openjdk.org/jfx/pull/1951#issuecomment-3558436154