RFR: 8345348: CSS media feature queries [v21]

[Andy Goryachev]

On Tue, 6 May 2025 18:45:47 GMT, Michael Strauß <mstrauss at openjdk.org> wrote:

>> Maybe a `volatile` would be a better choice then?
>
> `volatile` is not enough, because the different values are correlated (for example `foreground`, `background`, and `colorScheme`). All values need to be updated in a single transaction, as otherwise we could end up reading a transient combination of values.

I see.  The I suggest we enforce single-threaded nature of it: everything must happen in the FX Application Thread.  I don't think it's a good idea to start synchronizing things in FX now all of a sudden.

Any code that wants to access FX from a background thread must do so using a combination of `runLater` and a `CountDownLatch`.

What do you think?

-------------

PR Review Comment: https://git.openjdk.org/jfx/pull/1655#discussion_r2076069191