<AWT Dev> [8u/9] Review request: JDK-8028486 [TEST_BUG] [macosx] java/awt/Window/WindowsLeak/WindowsLeak.java fails

Sergey Bylokhov Sergey.Bylokhov at oracle.com
Fri Apr 29 12:22:23 UTC 2016

Hi, Anton.
It seems that the surface data will be leaked anyway? Assigned the 
peer/surfaceData to null in CGLayer can causes an NPE in all its usage, 
because there is no any synchronization which will prevent the usage of 
CGLayer after disposing.

Unrelated to the fix, but it seems we should call flush() on surface 
when the layer is disposed, at least I do not understand where we flush 
the native ogl data for the latest surface data.

On 29.04.16 15:00, Anton Tarasov wrote:
> Hi Sergey, Alexander,
> Please review the fix:
> bug: JDK-8028486 [TEST_BUG] [macosx] java/awt/Window/WindowsLeak/WindowsLeak.java fails
> webrev: http://cr.openjdk.java.net/~ant/JDK-8028486/webrev.0
> I’m copying my comment from CR:
> Please open the attached screenshot [*], made with YourKit, where a chain of links is shown from the GC roots.
> The frame is held by its peer which is held by CGLLayer which is held as validatedSrcData in the GL context.
> The point is that the GL context doesn't cleanup the last state until under some conditions, which are not applicable to this scenario.
> I'm not sure should the cleanup be triggered here or not, but the problem can be solved otherwise.
> The point is that in the chain the CGLLayer instance has been disposed, in response to the frame disposal.
> So, this is the only ref that holds it (the JNI ref is released by the native peer on disposal).
> Thus, as the layer is disposed it can at least zero all the java refs it holds (this change already fixes the problem).
> Then, the "layer" ref in CGLLayerSurfaceData should probably be made weak.
> [*] https://bugs.openjdk.java.net/secure/attachment/59121/8028486.png
> As to the “weak ref” mentioned in the comment. I didn’t do that, but if you find it reasonable I can add that change (or file a separate CR).
> Also, the fix contains some additional cleanup (not related to this CR): two more JNI local refs leak, fixed.
> Thanks,
> Anton.

Best regards, Sergey.

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