RFR: 8356687: [TestBug] SWT tests do not run on macOS

[Andy Goryachev]

On Tue, 9 Sep 2025 10:30:12 GMT, Jayathirth D V <jdv at openjdk.org> wrote:

> We have enabled swt tests under [JDK-8169285](https://bugs.openjdk.org/browse/JDK-8169285) but they were disabled on macOS as they throw below exception :
> 
> 
> FXCanvasScaledTest STANDARD_OUT
>     ***WARNING: Display must be created on main thread due to Cocoa restrictions. Use vmarg -XstartOnFirstThread
> 
> FXCanvasScaledTest > initializationError FAILED
>     org.eclipse.swt.SWTException: Invalid thread access
> 
> 
> Using `-XstartOnFirstThread` flag in gradle was not reliable and the issue was tracked under https://issues.gradle.org/browse/GRADLE-3290 and later under https://github.com/gradle/gradle/issues/864. This gradle issue is resolved and we can use `-XstartOnFirstThread` and enable SWT tests on macOS.
> 
> With `-XstartOnFirstThread`, SWT tests run fine on macOS.

1 reviewer should be enough (thanks Kevin!)

but just in case, the code changes look good (I did not run the build).

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Marked as reviewed by angorya (Reviewer).

PR Review: https://git.openjdk.org/jfx/pull/1888#pullrequestreview-3202437369