RFR: 8210547: [Linux] Uncontrolled framerate [v2]

[Lukasz Kostyra]

On Thu, 9 Oct 2025 04:01:52 GMT, notzed <duke at openjdk.org> wrote:

> > I don't know if there are scenarios when the unlimited frame rate is needed - if so we should provide a option.
> 
> Well if prism.vsync=false it wont call swapinterval and will just run at the pulse rate, plus there's javafx.animation.fullspeed?

`javafx.animation.fullspeed=true` has the same effect as `prism.vsync=false` and more. [Both disable vsync](https://github.com/openjdk/jfx/blob/master/modules/javafx.graphics/src/main/java/com/sun/prism/impl/PrismSettings.java#L118) in order to uncap the framerate from monitor's refresh rate, and in addition to that, `javafx.animation.fullspeed=true` also [sets the pulse timer to immediately trigger the next pulse](https://github.com/openjdk/jfx/blob/master/modules/javafx.graphics/src/main/java/com/sun/scenario/animation/AbstractPrimaryTimer.java#L263).

While not applicable during day-to-day JavaFX use, unlimited framerate can actually be quite useful. We currently actively use `javafx.animation.fullspeed=true` when working on Metal and D3D12 to do performance and stability testing. It would be good to keep it around and functional on Linux as well.

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PR Comment: https://git.openjdk.org/jfx/pull/1929#issuecomment-3384928497