On Tue, 28 Oct 2025 21:28:54 GMT, Andy Goryachev <[email protected]> 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.
>
> modules/javafx.graphics/src/main/java/com/sun/prism/d3d/D3DTexture.java line
> 91:
>
>> 89: public void update(MediaFrame frame, boolean skipFlush)
>> 90: {
>> 91: if (!resource.isValid()) {
>
> related - D3DTextureResource line 40 is
>
>
> public void free() {
> if (resource != null) {
> resource.dispose();
> }
> }
>
>
> should there be `resource = null;` after `resource.dispose()` ?
It could add another layer of safety and make any potential future NPEs more
easy to track - I'll add this.
> modules/javafx.graphics/src/main/java/com/sun/prism/d3d/D3DTexture.java line
> 93:
>
>> 91: if (!resource.isValid()) {
>> 92: return;
>> 93: }
>
> are these the only two places where we need the check?
Yes, as far as I know other Prism-backend-specific resources already do similar
checks, either Java side or Native side.
-------------
PR Review Comment: https://git.openjdk.org/jfx/pull/1951#discussion_r2472580324
PR Review Comment: https://git.openjdk.org/jfx/pull/1951#discussion_r2472576368
