Fix Bug 642 TestJSplitPaneMixHwLw01AWT (AWT-GLCanvas); Robustness GLContext/GLDrawable

- Fix Bug 642 TestJSplitPaneMixHwLw01AWT
  On Windows platform when mixing hw/lw JSplitPanel,
  the GLCanvas is removed and added when splitter is moved.
  The lack of robustness (see below) lead to an exception.

  Note: Only w/ GLJPanel (no hw/lw mixing) the splitter can be moved
  in both direction. Only here it is guaranteed that the GL component
  will survive the action.

- Fix AWT-GLCanvas EDT Runnable: swapBuffer().. / display(..)
  - Check drawable.isRealized() within the lock on the performing thread.
    This is not possible before issuing the EDT Runnable action
    since we cannot hold the lock beforehand.

- Robustness GLDrawableImpl
  - boolean realized -> volatile boolean realized
  - remove 'synchronized' on isRealized() and setRealized(..)
  - Use dbl-checked locking on 'realized' test for swapBuffers() and setRealized(..)

- Robustness GLContextImpl
  - Catch createImpl(..) exception and properly return CONTEXT_NOT_CURRENT

1 files changed, 4 insertions, 2 deletions

diff --git a/src/jogl/classes/javax/media/opengl/awt/GLCanvas.java b/src/jogl/classes/javax/media/opengl/awt/GLCanvas.java
index e5f39e5de..3877a7997 100644
--- a/src/jogl/classes/javax/media/opengl/awt/GLCanvas.java
+++ b/src/jogl/classes/javax/media/opengl/awt/GLCanvas.java
@@ -1024,7 +1024,9 @@ public class GLCanvas extends Canvas implements AWTGLAutoDrawable, WindowClosing
         final RecursiveLock _lock = lock;
         _lock.lock();
         try {
-            helper.invokeGL(drawable, context, displayAction, initAction);
+            if( drawable.isRealized() ) {
+                helper.invokeGL(drawable, context, displayAction, initAction);
+            }
         } finally {
             _lock.unlock();
         }
@@ -1037,7 +1039,7 @@ public class GLCanvas extends Canvas implements AWTGLAutoDrawable, WindowClosing
         final RecursiveLock _lock = lock;
         _lock.lock();
         try {
-            if(null != drawable) {
+            if(null != drawable && drawable.isRealized() ) {
                 drawable.swapBuffers();
             }
         } finally {