JVM hang with Swing and macOS

[Martin Pernollet]

Hi Sergey,

We access OpenGL through native bindings generated by JExtract, from project Panama. These bindings are packaged as a library visible here (https://gitlab.com/jzy3d/panama-gl).

The -XstartOnFirstThread option is needed by OpenGL on macOS as OpenGL invocation MUST be performed from macOS main thread. 

Not using this option on macOS lead to an error

java[92246:2751169] GLUT Fatal Error: internal error: NSInternalInconsistencyException, reason: NSWindow drag regions should only be invalidated on the Main Thread!

Using this option on macOS lead to a freeze in LockSupport.park() (see the attached image for the complete call stack)

JOGL has a smart way of solving this with a class allowing to push Runnables to macOS main thread (https://github.com/jzy3d/jogl/blob/ecf6e499d3b582d651a28693c871ca14d6e8c991/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java#L305) based on ObjectiveC code from Apple's AppKit framework (https://github.com/jzy3d/jogl/blob/ecf6e499d3b582d651a28693c871ca14d6e8c991/src/nativewindow/native/macosx/OSXmisc.m#L1167). 
This allows running on Swing without having to use the -XstartOnFirstThread.

However JOGL has several issues, one of these being that it freezes JVM>=19 as soon as it appears in the classpath (for other reasons than the one discussed above). 

This issue is a real pain for anyone publishing applications involving OpenGL in Swing - whatever the OpenGL binding framework. Not solving the issue would make project Panama unusable for computer graphics.

Regards,

Martin

------- Original Message -------
Le mardi 14 mars 2023 à 19:18, Sergey Bylokhov <bylokhov at amazon.com> a écrit :


> On 3/14/23 10:38, Martin Pernollet wrote:
> 
> > I work on projects involving OpenGL in Swing.
> > 
> > We are hitting anold JDK issue that prevent to properly run OpenGL on macOS+Swing
> > https://bugs.openjdk.org/browse/JDK-8289573. > You may know that Swing hangs on macOS when using -XstartOnFirstThread option. However, this option
> > is mandatory for native OpenGL to work on macOS (the reason is that OpenGL is single threaded and
> > that macOS impose to have all calls to OpenGL issued on the main macOS thread).
> 
> 
> Can you please add some details on what issue did you hit. That option is not needed when the app
> uses the built-in AWT/Swing, do your application use some external libraries like JOGL, SWT or JavaFX?
> 
> --
> Best regards, Sergey.
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