Bug 1054: GLContext: makeCurrent() needs a null-check of [mutable] drawable; Review null checks and synchronization/locking.

'drawable' field of GLContextImpl is mutable via setGLDrawable(..),
which requires high-level locking as documented.

The required high-level locking allows us to _not_ add special
synchronization to this field (and drawableRead).

A simple null-check in makeCurrent() shall be sufficient,
plus ensuring mentioned high-level locking is applied.

GLContextImpl 'drawable' and 'drawableRead' synchronization:
  - commit ad79bd072b600a3f2416cc6f0c61e2925000069d check of null drawable is sufficient
  - Add GLAutoDrawable upstream-lock locking to:
    - AWT GLCanvas setupPrint/releasePrint
    - AWT GLJPanel (was missing)

Misc:
  - validate shared-context native-surface locking, throw exception if not successful
  - pixelDataEvaluated does not need to be synchronized, since it's being called while context is current, locking
  - GLDrawableHelper.recreateGLDrawable(..): Remove redundant glFinish() call

1 files changed, 1 insertions, 2 deletions

diff --git a/src/jogl/classes/jogamp/opengl/GLDrawableHelper.java b/src/jogl/classes/jogamp/opengl/GLDrawableHelper.java
index f91e1bdba..25ff83fc0 100644
--- a/src/jogl/classes/jogamp/opengl/GLDrawableHelper.java
+++ b/src/jogl/classes/jogamp/opengl/GLDrawableHelper.java
@@ -282,7 +282,6 @@ public class GLDrawableHelper {
           if( currentContext != context ) {
               context.makeCurrent();
           }
-          context.getGL().glFinish();
           context.setGLDrawable(null, true); // dis-associate
       }
 
@@ -300,7 +299,7 @@ public class GLDrawableHelper {
       }
 
       if(null != context) {
-          context.setGLDrawable(drawable, true); // re-association
+          context.setGLDrawable(drawable, true); // re-association, implicit glFinish() ctx/drawable sync
       }
 
       if( null != currentContext ) {