X11 warning/error message

Hi,

A user running a 64bit version of CentOS reports the following message when my application creates a new JFrame with a Canvas3D and that her computer monitor goes black, but reappears with the new window displayed:

X11Util.Display: Shutdown (JVM shutdown: true, open (no close attempt): 8/8, reusable (open, marked uncloseable): 0, pending (open in creation order): 8)
X11Util: Open X11 Display Connections: 8
X11Util: Open[0]: NamedX11Display[:0.0, 0x7f5238004980, refCount 1, unCloseable false]
X11Util: Open[1]: NamedX11Display[:0.0, 0x7f5238062100, refCount 1, unCloseable false]
X11Util: Open[2]: NamedX11Display[:0.0, 0x7f5238437fc0, refCount 1, unCloseable false]
X11Util: Open[3]: NamedX11Display[:0.0, 0x7f5238436d50, refCount 1, unCloseable false]
X11Util: Open[4]: NamedX11Display[:0.0, 0x7f5238741e20, refCount 1, unCloseable false]
X11Util: Open[5]: NamedX11Display[:0.0, 0x7f5238466850, refCount 1, unCloseable false]
X11Util: Open[6]: NamedX11Display[:0.0, 0x7f52384b8360, refCount 1, unCloseable false]
X11Util: Open[7]: NamedX11Display[:0.0, 0x7f5238975060, refCount 1, unCloseable false]

Any guidance much appreciated.

Tom

How do you close your canvases?

How should a Canvas3D be closed when closing the associated JFrame to free resources?

Here's what we're doing now:

from a WindowEvent (closing) so on the EDT:

   View.removeCanvas3D()
   View.attachViewPlatform(null)  // was recommended in earlier versions of Java3D
   Universe.removeAllLocales()

   Locale->BranchGroup.detach()  // top level scene branch

   Frame.dispose()

Can you recommend a better procedure?

But I'm not sure why the computer monitor would blank out before opening a JFrame with a Canvas3D.  This
was with pre9, so I will verify with pre11.