RFR: 8255248: NullPointerException in JFXPanel due to race condition in HostContainer [v4]

[Prasanta Sadhukhan]

On Mon, 17 Nov 2025 16:35:50 GMT, Prasanta Sadhukhan <psadhukhan at openjdk.org> wrote:

>> NPE is seen while accessing transient "scenePeer" variable between reads..
>> Fix is made to store it in a temp variable rather than reading it twice since the value can change between successive reads in many places it is accessed.
>> Also some debug logs added to be enabled via `jfxpanel.debug` property
>
> Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove debug, store transient var in temp var in EDT methods

Modified PR to add comments to specify which methods and fields are called on which threads

> > Ideally, this component should be redesigned to ensure proper communication between threads.
> 
> That would be the best long-term solution, but that would be a large effort.

Synchronizing at atomic granularity needs to be done but many methods internally context switch to other thread which can be problematic for this so I have followed the present approach..

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PR Comment: https://git.openjdk.org/jfx/pull/1968#issuecomment-3547632132