Fix OSX CALayer Bug 690 and Bug 691: Occasional Freeze on CVDisplayLinkStop; Layers and native GL-Context are _not_ Released ; Java Side wait for Main-Thread

- Fix Bug 690: Occasional Freeze on CVDisplayLinkStop
  - NSOpenGLLayer.disableAnimation() shall not claim the renderLock mutex,
    since the CVDisplayLink callback could be waiting for the lock.
    This waiting callback could freeze the call to CVDisplayLinkStop.

- Fix Bug 691: Layers and native GL-Context are _not_ Released
  - Following proper release cycle:

    Context unrealized:
      - JAWTWindow.detachSurfaceLayer() -> OSXUtil.RemoveCASublayer(..)
      - CGL.releaseNSOpenGLLayer(..)

    JAWTWindow.destroy()
      - MacOSXJAWTWindow.UnsetJAWTRootSurfaceLayer(..)
      - OSXUtil.DestroyCALayer(..)

  - 'Magic' CALayer release calls (w/o manual retain beforehand) at:
     - OSXUtil.RemoveCASublayer(..): [subLayer release]
     - MacOSXJAWTWindow.UnsetJAWTRootSurfaceLayer(..): [rootLayer release]
     - OSXUtil.DestroyCALayer(..): [rootLayer release]

  - 'Magic' NSOpenGLLayer's NSOpenGLContext dealloc:
     - [NSOpenGLContext clearDrawable]
     - CGLDestroyContext( [NSOpenGLContext CGLContextObj] )

- Java Side wait for Main-Thread
  - Waiting for the delegated Main-Thread on the Java side eases debugging
    and won't block the Main-Thread in native code.

  - Utilizing this for all CALayer calls

Test case: TestGLCanvasAddRemove01SwingAWT

9 files changed, 581 insertions, 134 deletions

diff --git a/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLContext.java b/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLContext.java
index 838a0387d..0deaa2987 100644
--- a/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLContext.java
+++ b/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLContext.java
@@ -709,7 +709,10 @@ public abstract class MacOSXCGLContext extends GLContextImpl
                       // still having a valid OLS attached to surface (parent OLS could have been removed)
                       ols.detachSurfaceLayer();
                   }
-                  CGL.releaseNSOpenGLLayer(nsOpenGLLayer);
+                  OSXUtil.RunOnMainThread(true, new Runnable() {
+                      public void run() {
+                          CGL.releaseNSOpenGLLayer(nsOpenGLLayer);
+                      } } );                  
                   if( null != gl3ShaderProgram ) {
                       gl3ShaderProgram.destroy(MacOSXCGLContext.this.gl.getGL3());
                       gl3ShaderProgram = null;
diff --git a/src/jogl/native/macosx/MacOSXWindowSystemInterface-calayer.m b/src/jogl/native/macosx/MacOSXWindowSystemInterface-calayer.m
index b37930587..4334fc676 100644
--- a/src/jogl/native/macosx/MacOSXWindowSystemInterface-calayer.m
+++ b/src/jogl/native/macosx/MacOSXWindowSystemInterface-calayer.m
@@ -41,6 +41,8 @@ extern GLboolean glIsVertexArray (GLuint array);
 //
 // #define DBG_PERF 1
 
+// #define DBG_LIFECYCLE 1
+
 /**
  * Capture setView(NULL), which produces a 'invalid drawable' message
  *
@@ -52,6 +54,10 @@ extern GLboolean glIsVertexArray (GLuint array);
 - (id)initWithFormat:(NSOpenGLPixelFormat *)format shareContext:(NSOpenGLContext *)share;
 - (void)setView:(NSView *)view;
 - (void)update;
+#ifdef DBG_LIFECYCLE
+- (id)retain;
+- (oneway void)release;
+#endif
 - (void)dealloc;
 
 @end
@@ -82,11 +88,36 @@ extern GLboolean glIsVertexArray (GLuint array);
     DBG_PRINT("MyNSOpenGLContext.update.X\n");
 }
 
+#ifdef DBG_LIFECYCLE
+
+- (id)retain
+{
+    DBG_PRINT("MyNSOpenGLContext::retain.0: %p (refcnt %d)\n", self, (int)[self retainCount]);
+    // NSLog(@"MyNSOpenGLContext::retain: %@",[NSThread callStackSymbols]);
+    id o = [super retain];
+    DBG_PRINT("MyNSOpenGLContext::retain.X: %p (refcnt %d)\n", o, (int)[o retainCount]);
+    return o;
+}
+
+- (oneway void)release
+{
+    DBG_PRINT("MyNSOpenGLContext::release.0: %p (refcnt %d)\n", self, (int)[self retainCount]);
+    [super release];
+    // DBG_PRINT("MyNSOpenGLContext::release.X: %p (refcnt %d)\n", self, (int)[self retainCount]);
+}
+
+#endif
+
 - (void)dealloc
 {
-    DBG_PRINT("MyNSOpenGLContext.dealloc: this.0 %p\n", self);
+    CGLContextObj cglCtx = [self CGLContextObj];
+    DBG_PRINT("MyNSOpenGLContext::dealloc.0 %p (refcnt %d) - CGL-Ctx %p\n", self, (int)[self retainCount], cglCtx);
+    [self clearDrawable];
+    if( NULL != cglCtx ) {
+        CGLDestroyContext( cglCtx );
+    }
     [super dealloc];
-    DBG_PRINT("MyNSOpenGLContext.dealloc.X: %p\n", self);
+    // DBG_PRINT("MyNSOpenGLContext.dealloc.X: %p\n", self);
 }
 
 @end
@@ -95,6 +126,7 @@ extern GLboolean glIsVertexArray (GLuint array);
 {
 @private
     GLfloat gl_texCoords[8];
+    NSOpenGLContext* myCtx;
 
 @protected
     NSOpenGLContext* parentCtx;
@@ -150,6 +182,10 @@ extern GLboolean glIsVertexArray (GLuint array);
 - (void)pauseAnimation:(Bool)pause;
 - (void)deallocPBuffer;
 - (void)releaseLayer;
+#ifdef DBG_LIFECYCLE
+- (id)retain;
+- (oneway void)release;
+#endif
 - (void)dealloc;
 - (void)setSwapInterval:(int)interval;
 - (void)tick;
@@ -209,6 +245,7 @@ static const GLfloat gl_verts[] = {
     pthread_mutex_init(&renderLock, &renderLockAttr); // recursive
     pthread_cond_init(&renderSignal, NULL); // no attribute
 
+    myCtx = NULL;
     {
         int i;
         for(i=0; i<8; i++) {
@@ -418,15 +455,15 @@ static const GLfloat gl_verts[] = {
 {
     DBG_PRINT("MyNSOpenGLLayer::openGLContextForPixelFormat.0: %p (refcnt %d) - pfmt %p, parent %p\n",
         self, (int)[self retainCount], pixelFormat, parentCtx);
-    NSOpenGLContext * nctx = [[MyNSOpenGLContext alloc] initWithFormat:pixelFormat shareContext:parentCtx];
-    DBG_PRINT("MyNSOpenGLLayer::openGLContextForPixelFormat.X: new-ctx %p\n", nctx);
-    return nctx;
+    // NSLog(@"MyNSOpenGLLayer::openGLContextForPixelFormat: %@",[NSThread callStackSymbols]);
+    myCtx = [[MyNSOpenGLContext alloc] initWithFormat:pixelFormat shareContext:parentCtx];
+    DBG_PRINT("MyNSOpenGLLayer::openGLContextForPixelFormat.X: new-ctx %p\n", myCtx);
+    return myCtx;
 }
 
 - (void)disableAnimation
 {
-    DBG_PRINT("MyNSOpenGLLayer::disableAnimation: %p (refcnt %d) - displayLink %p\n", self, (int)[self retainCount], displayLink);
-    pthread_mutex_lock(&renderLock);
+    DBG_PRINT("MyNSOpenGLLayer::disableAnimation.0: %p (refcnt %d) - displayLink %p\n", self, (int)[self retainCount], displayLink);
     [self setAsynchronous: NO];
     if(NULL != displayLink) {
 #ifdef HAS_CADisplayLink
@@ -438,35 +475,63 @@ static const GLfloat gl_verts[] = {
 #endif
         displayLink = NULL;
     }
-    pthread_mutex_unlock(&renderLock);
+    DBG_PRINT("MyNSOpenGLLayer::disableAnimation.X: %p (refcnt %d) - displayLink %p\n", self, (int)[self retainCount], displayLink);
 }
 
 - (void)releaseLayer
 {
     DBG_PRINT("MyNSOpenGLLayer::releaseLayer.0: %p (refcnt %d)\n", self, (int)[self retainCount]);
-    pthread_mutex_lock(&renderLock);
     [self disableAnimation];
+    pthread_mutex_lock(&renderLock);
     [self deallocPBuffer];
-    [[self openGLContext] release];
+    // [[self openGLContext] release];
+    if( NULL != myCtx ) {
+        [myCtx release];
+        // [myCtx dealloc];
+        myCtx = NULL;
+    }
+    parentCtx = NULL;
     [parentPixelFmt release];
-    [self release];
-    DBG_PRINT("MyNSOpenGLLayer::releaseLayer.X: %p (refcnt %d)\n", self, (int)[self retainCount]);
     pthread_mutex_unlock(&renderLock);
+    [self release];
+    DBG_PRINT("MyNSOpenGLLayer::releaseLayer.X: %p\n", self);
 }
 
+#ifdef DBG_LIFECYCLE
+
+- (id)retain
+{
+    DBG_PRINT("MyNSOpenGLLayer::retain.0: %p (refcnt %d)\n", self, (int)[self retainCount]);
+    // NSLog(@"MyNSOpenGLLayer::retain: %@",[NSThread callStackSymbols]);
+    id o = [super retain];
+    DBG_PRINT("MyNSOpenGLLayer::retain.X: %p (refcnt %d)\n", o, (int)[o retainCount]);
+    return o;
+}
+
+- (oneway void)release
+{
+    DBG_PRINT("MyNSOpenGLLayer::release.0: %p (refcnt %d)\n", self, (int)[self retainCount]);
+    // NSLog(@"MyNSOpenGLLayer::release: %@",[NSThread callStackSymbols]);
+    [super release];
+    // DBG_PRINT("MyNSOpenGLLayer::release.X: %p (refcnt %d)\n", self, (int)[self retainCount]);
+}
+
+#endif
+
 - (void)dealloc
 {
     DBG_PRINT("MyNSOpenGLLayer::dealloc.0 %p (refcnt %d)\n", self, (int)[self retainCount]);
     // NSLog(@"MyNSOpenGLLayer::dealloc: %@",[NSThread callStackSymbols]);
 
-    pthread_mutex_lock(&renderLock);
     [self disableAnimation];
+    pthread_mutex_lock(&renderLock);
     [self deallocPBuffer];
+    // [[self openGLContext] dealloc];
     pthread_mutex_unlock(&renderLock);
     pthread_cond_destroy(&renderSignal);
     pthread_mutex_destroy(&renderLock);
     [super dealloc];
-    DBG_PRINT("MyNSOpenGLLayer::dealloc.X %p\n", self);
+    // DBG_PRINT("MyNSOpenGLLayer::dealloc.X %p\n", self);
 }
 
 - (Bool)isGLSourceValid
@@ -752,32 +817,27 @@ static const GLfloat gl_verts[] = {
 @end
 
 NSOpenGLLayer* createNSOpenGLLayer(NSOpenGLContext* ctx, int gl3ShaderProgramName, NSOpenGLPixelFormat* fmt, NSOpenGLPixelBuffer* p, uint32_t texID, Bool opaque, int texWidth, int texHeight) {
-  // This simply crashes after dealloc() has been called .. ie. ref-count -> 0 too early ?
-  // However using alloc/init, actual dealloc happens at JAWT destruction, hence too later IMHO.
-  // return [[MyNSOpenGLLayer layer] setupWithContext:ctx pixelFormat: fmt pbuffer: p texIDArg: (GLuint)texID
-  //                                                      opaque: opaque texWidth: texWidth texHeight: texHeight];
-
   return [[[MyNSOpenGLLayer alloc] init] setupWithContext:ctx gl3ShaderProgramName: (GLuint)gl3ShaderProgramName pixelFormat: fmt pbuffer: p texIDArg: (GLuint)texID
                                                               opaque: opaque texWidth: texWidth texHeight: texHeight];
 }
 
 void setNSOpenGLLayerSwapInterval(NSOpenGLLayer* layer, int interval) {
-    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
+    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     [l setSwapInterval: interval];
     [pool release];
 }
 
 void waitUntilNSOpenGLLayerIsReady(NSOpenGLLayer* layer, long to_micros) {
-    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
+    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     [l waitUntilRenderSignal: to_micros];
     [pool release];
 }
 
 void setNSOpenGLLayerNeedsDisplayFBO(NSOpenGLLayer* layer, uint32_t texID) {
-    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
+    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     Bool shallDraw;
 
     // volatile OK
@@ -799,8 +859,8 @@ void setNSOpenGLLayerNeedsDisplayFBO(NSOpenGLLayer* layer, uint32_t texID) {
 }
 
 void setNSOpenGLLayerNeedsDisplayPBuffer(NSOpenGLLayer* layer, NSOpenGLPixelBuffer* p) {
-    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
+    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     Bool shallDraw;
 
     if( NO == [l isSamePBuffer: p] ) {
@@ -825,16 +885,10 @@ void setNSOpenGLLayerNeedsDisplayPBuffer(NSOpenGLLayer* layer, NSOpenGLPixelBuff
 }
 
 void releaseNSOpenGLLayer(NSOpenGLLayer* layer) {
-    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
+    MyNSOpenGLLayer* l = (MyNSOpenGLLayer*) layer;
     DBG_PRINT("MyNSOpenGLLayer::releaseNSOpenGLLayer.0: %p\n", l);
-
-    if ( [NSThread isMainThread] == YES ) {
-        [l releaseLayer];
-    } else { 
-        [l performSelectorOnMainThread:@selector(releaseLayer) withObject:nil waitUntilDone:NO];
-    }
-
+    [l releaseLayer];
     DBG_PRINT("MyNSOpenGLLayer::releaseNSOpenGLLayer.X: %p\n", l);
     [pool release];
 }
diff --git a/src/nativewindow/classes/com/jogamp/nativewindow/awt/JAWTWindow.java b/src/nativewindow/classes/com/jogamp/nativewindow/awt/JAWTWindow.java
index 8527a0200..007a917a6 100644
--- a/src/nativewindow/classes/com/jogamp/nativewindow/awt/JAWTWindow.java
+++ b/src/nativewindow/classes/com/jogamp/nativewindow/awt/JAWTWindow.java
@@ -205,7 +205,7 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
       }
       try {
           if(DEBUG) {
-            System.err.println("JAWTWindow.attachSurfaceHandle(): 0x"+Long.toHexString(layerHandle) + ", bounds "+bounds);
+            System.err.println("JAWTWindow.attachSurfaceHandle(): "+toHexString(layerHandle) + ", bounds "+bounds);
           }
           attachSurfaceLayerImpl(layerHandle);
           offscreenSurfaceLayer = layerHandle;
@@ -229,7 +229,7 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
       }
       try {
           if(DEBUG) {
-            System.err.println("JAWTWindow.detachSurfaceHandle(): 0x"+Long.toHexString(offscreenSurfaceLayer));
+            System.err.println("JAWTWindow.detachSurfaceHandle(): osh "+toHexString(offscreenSurfaceLayer));
           }
           detachSurfaceLayerImpl(offscreenSurfaceLayer);
           offscreenSurfaceLayer = 0;
@@ -341,7 +341,7 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
                     if(LOCK_SUCCESS == res && drawable_old != drawable) {
                         res = LOCK_SURFACE_CHANGED;
                         if(DEBUG) {
-                            System.err.println("JAWTWindow: surface change 0x"+Long.toHexString(drawable_old)+" -> 0x"+Long.toHexString(drawable));
+                            System.err.println("JAWTWindow: surface change "+toHexString(drawable_old)+" -> "+toHexString(drawable));
                             // Thread.dumpStack();
                         }
                     }
@@ -549,8 +549,8 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
     StringBuilder sb = new StringBuilder();
 
     sb.append("JAWT-Window["+
-                "windowHandle 0x"+Long.toHexString(getWindowHandle())+
-                ", surfaceHandle 0x"+Long.toHexString(getSurfaceHandle())+
+                "windowHandle "+toHexString(getWindowHandle())+
+                ", surfaceHandle "+toHexString(getSurfaceHandle())+
                 ", bounds "+bounds+", insets "+insets+
                 ", shallUseOffscreenLayer "+shallUseOffscreenLayer+", isOffscreenLayerSurface "+isOffscreenLayerSurface);
     if(null!=component) {
@@ -566,4 +566,8 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
 
     return sb.toString();
   }
+  
+  protected final String toHexString(long l) {
+      return "0x"+Long.toHexString(l);
+  }
 }
diff --git a/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java b/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java
index 2b49f6745..5479f2495 100644
--- a/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java
+++ b/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java
@@ -38,7 +38,6 @@ import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.widgets.Control;
 
 import javax.media.nativewindow.AbstractGraphicsScreen;
-import javax.media.nativewindow.DefaultGraphicsScreen;
 import javax.media.nativewindow.NativeWindowException;
 import javax.media.nativewindow.AbstractGraphicsDevice;
 import javax.media.nativewindow.NativeWindowFactory;
@@ -49,7 +48,6 @@ import com.jogamp.common.util.VersionNumber;
 import com.jogamp.nativewindow.macosx.MacOSXGraphicsDevice;
 import com.jogamp.nativewindow.windows.WindowsGraphicsDevice;
 import com.jogamp.nativewindow.x11.X11GraphicsDevice;
-import com.jogamp.nativewindow.x11.X11GraphicsScreen;
 
 import jogamp.nativewindow.macosx.OSXUtil;
 import jogamp.nativewindow.x11.X11Lib;
diff --git a/src/nativewindow/classes/jogamp/nativewindow/jawt/macosx/MacOSXJAWTWindow.java b/src/nativewindow/classes/jogamp/nativewindow/jawt/macosx/MacOSXJAWTWindow.java
index 9e270d403..9b06cce1a 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/jawt/macosx/MacOSXJAWTWindow.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/jawt/macosx/MacOSXJAWTWindow.java
@@ -51,6 +51,7 @@ import javax.media.nativewindow.NativeWindowException;
 import javax.media.nativewindow.MutableSurface;
 import javax.media.nativewindow.util.Point;
 
+import com.jogamp.common.util.Function;
 import com.jogamp.nativewindow.awt.JAWTWindow;
 
 import jogamp.nativewindow.jawt.JAWT;
@@ -70,11 +71,40 @@ public class MacOSXJAWTWindow extends JAWTWindow implements MutableSurface {
   }
 
   protected void invalidateNative() {
+      if(DEBUG) {
+          System.err.println("MacOSXJAWTWindow.invalidateNative(): osh-enabled "+isOffscreenLayerSurfaceEnabled()+
+                             ", osh-set "+offscreenSurfaceHandleSet+
+                             ", osh "+toHexString(offscreenSurfaceHandle)+
+                             ", rsh "+toHexString(rootSurfaceLayerHandle)+
+                             ", wh "+toHexString(windowHandle));
+      }
       offscreenSurfaceHandle=0;
       offscreenSurfaceHandleSet=false;
-      if(isOffscreenLayerSurfaceEnabled()) {
+      if( isOffscreenLayerSurfaceEnabled() ) {
           if(0 != rootSurfaceLayerHandle) {
+              final JAWT jawt = getJAWT();
+              if( null != jawt ) {
+                  final JAWT_DrawingSurface ds = jawt.GetDrawingSurface(component);
+                  if (ds != null) {
+                      if ( 0 == ( ds.Lock() & JAWTFactory.JAWT_LOCK_ERROR ) ) {
+                          JAWT_DrawingSurfaceInfo dsi = null;
+                          try {
+                              dsi = ds.GetDrawingSurfaceInfo();
+                              if(! UnsetJAWTRootSurfaceLayer(dsi.getBuffer(), rootSurfaceLayerHandle)) {
+                                  System.err.println("Error clearing JAWT rootSurfaceLayerHandle "+toHexString(rootSurfaceLayerHandle));
+                              }
+                          } finally {
+                              if ( null != dsi ) {
+                                  ds.FreeDrawingSurfaceInfo(dsi);
+                              }
+                              ds.Unlock();
+                          }
+                      }
+                      jawt.FreeDrawingSurface(ds);
+                  }
+              }
               OSXUtil.DestroyCALayer(rootSurfaceLayerHandle);
+              
               rootSurfaceLayerHandle = 0;
           }
           if(0 != windowHandle) {
@@ -107,7 +137,7 @@ public class MacOSXJAWTWindow extends JAWTWindow implements MutableSurface {
           throw new java.lang.UnsupportedOperationException("Not using CALAYER");
       }
       if(DEBUG) {
-        System.err.println("MacOSXJAWTWindow.setSurfaceHandle(): 0x"+Long.toHexString(surfaceHandle));
+        System.err.println("MacOSXJAWTWindow.setSurfaceHandle(): "+toHexString(surfaceHandle));
       }
       this.offscreenSurfaceHandle = surfaceHandle;
       this.offscreenSurfaceHandleSet = true;
@@ -117,6 +147,7 @@ public class MacOSXJAWTWindow extends JAWTWindow implements MutableSurface {
        // use offscreen if supported and [ applet or requested ]
       return JAWTUtil.getJAWT(getShallUseOffscreenLayer() || isApplet());
   }
+  
   protected int lockSurfaceImpl() throws NativeWindowException {
     int ret = NativeWindow.LOCK_SURFACE_NOT_READY;
     ds = getJAWT().GetDrawingSurface(component);
@@ -189,7 +220,7 @@ public class MacOSXJAWTWindow extends JAWTWindow implements MutableSurface {
             } else {
                 drawable = OSXUtil.GetNSView(windowHandle);
                 if(0 == drawable) {
-                  errMsg = "Null NSView of NSWindow 0x"+Long.toHexString(windowHandle);
+                  errMsg = "Null NSView of NSWindow "+toHexString(windowHandle);
                 }
             }
             if(null == errMsg) {
@@ -204,8 +235,8 @@ public class MacOSXJAWTWindow extends JAWTWindow implements MutableSurface {
                 rootSurfaceLayerHandle = OSXUtil.CreateCALayer(bounds.getX(), bounds.getY(), bounds.getWidth(), bounds.getHeight());
                 if(0 == rootSurfaceLayerHandle) {
                   errMsg = "Could not create root CALayer";                
-                } else if(!SetJAWTRootSurfaceLayer0(dsi.getBuffer(), rootSurfaceLayerHandle)) {
-                  errMsg = "Could not set JAWT rootSurfaceLayerHandle 0x"+Long.toHexString(rootSurfaceLayerHandle);
+                } else if(!SetJAWTRootSurfaceLayer(dsi.getBuffer(), rootSurfaceLayerHandle)) {
+                  errMsg = "Could not set JAWT rootSurfaceLayerHandle "+toHexString(rootSurfaceLayerHandle);
                 }
             }
         }
@@ -265,9 +296,23 @@ public class MacOSXJAWTWindow extends JAWTWindow implements MutableSurface {
       return getLocationOnScreenNonBlocking(storage, component);     
   }  
   protected Point getLocationOnScreenNativeImpl(final int x0, final int y0) { return null; }
+  
+  private static boolean SetJAWTRootSurfaceLayer(final Buffer jawtDrawingSurfaceInfoBuffer, final long caLayer) {
+      return OSXUtil.RunOnMainThread(true, new Function<Boolean, Object>() {
+       public Boolean eval(Object... args) {
+           return Boolean.valueOf( SetJAWTRootSurfaceLayer0(jawtDrawingSurfaceInfoBuffer, caLayer) );
+       } } ).booleanValue();
+  }
+
+  private static boolean UnsetJAWTRootSurfaceLayer(final Buffer jawtDrawingSurfaceInfoBuffer, final long caLayer) {
+      return OSXUtil.RunOnMainThread(true, new Function<Boolean, Object>() {
+       public Boolean eval(Object... args) {
+           return Boolean.valueOf( UnsetJAWTRootSurfaceLayer0(jawtDrawingSurfaceInfoBuffer, caLayer) );
+       } } ).booleanValue();      
+  }
 
   private static native boolean SetJAWTRootSurfaceLayer0(Buffer jawtDrawingSurfaceInfoBuffer, long caLayer);
-  // private static native boolean UnsetJAWTRootSurfaceLayer0(Buffer jawtDrawingSurfaceInfoBuffer, long caLayer);
+  private static native boolean UnsetJAWTRootSurfaceLayer0(Buffer jawtDrawingSurfaceInfoBuffer, long caLayer);
   
   // Variables for lockSurface/unlockSurface
   private JAWT_DrawingSurface ds;
diff --git a/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java b/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java
index f06f97064..2e133c22f 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java
@@ -32,6 +32,8 @@ import javax.media.nativewindow.NativeWindowFactory;
 import javax.media.nativewindow.util.Insets;
 import javax.media.nativewindow.util.Point;
 
+import com.jogamp.common.util.Function;
+import com.jogamp.common.util.FunctionTask;
 import com.jogamp.common.util.RunnableTask;
 
 import jogamp.nativewindow.Debug;
@@ -137,23 +139,33 @@ public class OSXUtil implements ToolkitProperties {
     public static long CreateCALayer(int x, int y, int width, int height) {
         return CreateCALayer0(x, y, width, height);
     }
-    public static void AddCASublayer(long rootCALayer, long subCALayer) {
+    public static void AddCASublayer(final long rootCALayer, final long subCALayer) {
         if(0==rootCALayer || 0==subCALayer) {
             throw new IllegalArgumentException("rootCALayer 0x"+Long.toHexString(rootCALayer)+", subCALayer 0x"+Long.toHexString(subCALayer));
         }
-        AddCASublayer0(rootCALayer, subCALayer);
+        RunOnMainThread(true, new Runnable() {
+           public void run() {
+               AddCASublayer0(rootCALayer, subCALayer);               
+           }
+        });
     }
-    public static void RemoveCASublayer(long rootCALayer, long subCALayer) {
+    public static void RemoveCASublayer(final long rootCALayer, final long subCALayer) {
         if(0==rootCALayer || 0==subCALayer) {
             throw new IllegalArgumentException("rootCALayer 0x"+Long.toHexString(rootCALayer)+", subCALayer 0x"+Long.toHexString(subCALayer));
         }
-        RemoveCASublayer0(rootCALayer, subCALayer);
+        RunOnMainThread(true, new Runnable() {
+           public void run() {
+               RemoveCASublayer0(rootCALayer, subCALayer);
+           } } );
     }
-    public static void DestroyCALayer(long caLayer) {
+    public static void DestroyCALayer(final long caLayer) {
         if(0==caLayer) {
             throw new IllegalArgumentException("caLayer 0x"+Long.toHexString(caLayer));
         }
-        DestroyCALayer0(caLayer);    
+        RunOnMainThread(true, new Runnable() {
+           public void run() {        
+               DestroyCALayer0(caLayer);
+           } } );
     }
     
     /**
@@ -169,14 +181,14 @@ public class OSXUtil implements ToolkitProperties {
         if( IsMainThread0() ) {
             runnable.run(); // don't leave the JVM
         } else {
-            if( waitUntilDone ) {
-                // Utilize Java side lock/wait and simply pass the Runnable async to OSX main thread,
-                // otherwise we may freeze the OSX main thread.            
-                Throwable throwable = null;
-                final Object sync = new Object();
-                final RunnableTask rt = new RunnableTask( runnable, sync, true ); 
-                synchronized(sync) {
-                    RunOnMainThread0(rt);
+            // Utilize Java side lock/wait and simply pass the Runnable async to OSX main thread,
+            // otherwise we may freeze the OSX main thread.            
+            Throwable throwable = null;
+            final Object sync = new Object();
+            final RunnableTask rt = new RunnableTask( runnable, waitUntilDone ? sync : null, true ); 
+            synchronized(sync) {
+                RunOnMainThread0(rt);
+                if( waitUntilDone ) {
                     try {
                         sync.wait();
                     } catch (InterruptedException ie) {
@@ -188,10 +200,47 @@ public class OSXUtil implements ToolkitProperties {
                     if(null!=throwable) {
                         throw new RuntimeException(throwable);
                     }
-                }                
-            } else {
-                RunOnMainThread0(runnable);
+                }
+            }
+        }
+    }
+    
+    /**
+     * Run on OSX UI main thread.
+     * <p> 
+     * 'waitUntilDone' is implemented on Java site via lock/wait on {@link FunctionTask} to not freeze OSX main thread.
+     * </p>
+     * 
+     * @param waitUntilDone
+     * @param func
+     */
+    public static <R,A> R RunOnMainThread(boolean waitUntilDone, Function<R,A> func, A... args) {
+        if( IsMainThread0() ) {
+            return func.eval(args); // don't leave the JVM
+        } else {
+            // Utilize Java side lock/wait and simply pass the Runnable async to OSX main thread,
+            // otherwise we may freeze the OSX main thread.            
+            Throwable throwable = null;
+            final Object sync = new Object();
+            final FunctionTask<R,A> rt = new FunctionTask<R,A>( func, waitUntilDone ? sync : null, true ); 
+            synchronized(sync) {
+                rt.setArgs(args);
+                RunOnMainThread0(rt);
+                if( waitUntilDone ) {
+                    try {
+                        sync.wait();
+                    } catch (InterruptedException ie) {
+                        throwable = ie;
+                    }
+                    if(null==throwable) {
+                        throwable = rt.getThrowable();
+                    }
+                    if(null!=throwable) {
+                        throw new RuntimeException(throwable);
+                    }
+                }
             }
+            return rt.getResult();
         }
     }
     
diff --git a/src/nativewindow/native/macosx/OSXmisc.m b/src/nativewindow/native/macosx/OSXmisc.m
index 72bb2338c..3fa320042 100644
--- a/src/nativewindow/native/macosx/OSXmisc.m
+++ b/src/nativewindow/native/macosx/OSXmisc.m
@@ -49,6 +49,16 @@
     #define DBG_PRINT(...)
 #endif
 
+// #define VERBOSE2 1
+//
+#ifdef VERBOSE2
+    #define DBG_PRINT2(...) fprintf(stderr, __VA_ARGS__); fflush(stderr)
+#else
+    #define DBG_PRINT2(...)
+#endif
+
+// #define DBG_LIFECYCLE 1
+
 static const char * const ClazzNameRunnable = "java/lang/Runnable";
 static jmethodID runnableRunID = NULL;
 
@@ -324,7 +334,7 @@ JNIEXPORT jlong JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_CreateCALayer0
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
 
     CALayer* layer = [[CALayer alloc] init];
-    DBG_PRINT("CALayer::CreateCALayer.0: %p %d/%d %dx%d (refcnt %d)\n", layer, (int)x, (int)y, (int)width, (int)height, (int)[layer retainCount]);
+    DBG_PRINT("CALayer::CreateCALayer.0: root %p %d/%d %dx%d (refcnt %d)\n", layer, (int)x, (int)y, (int)width, (int)height, (int)[layer retainCount]);
     // avoid zero size
     if(0 == width) { width = 32; }
     if(0 == height) { height = 32; }
@@ -341,8 +351,8 @@ JNIEXPORT jlong JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_CreateCALayer0
     [layer removeAllAnimations];
     [layer setAutoresizingMask: (kCALayerWidthSizable|kCALayerHeightSizable)];
     [layer setNeedsDisplayOnBoundsChange: YES];
-    DBG_PRINT("CALayer::CreateCALayer.1: %p %lf/%lf %lfx%lf\n", layer, lRect.origin.x, lRect.origin.y, lRect.size.width, lRect.size.height);
-    DBG_PRINT("CALayer::CreateCALayer.X: %p (refcnt %d)\n", layer, (int)[layer retainCount]);
+    DBG_PRINT("CALayer::CreateCALayer.1: root %p %lf/%lf %lfx%lf\n", layer, lRect.origin.x, lRect.origin.y, lRect.size.width, lRect.size.height);
+    DBG_PRINT("CALayer::CreateCALayer.X: root %p (refcnt %d)\n", layer, (int)[layer retainCount]);
 
     [pool release];
 
@@ -367,30 +377,28 @@ JNIEXPORT void JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_AddCASublayer0
     if(lRectRoot.origin.x!=0 || lRectRoot.origin.y!=0) {
         lRectRoot.origin.x = 0;
         lRectRoot.origin.y = 0;
-        [JNFRunLoop performOnMainThreadWaiting:YES withBlock:^(){
-            [rootLayer setFrame: lRectRoot];
-        }];
+        [rootLayer setFrame: lRectRoot];
         DBG_PRINT("CALayer::AddCASublayer0.1: Origin %p frame*: %lf/%lf %lfx%lf\n", 
             rootLayer, lRectRoot.origin.x, lRectRoot.origin.y, lRectRoot.size.width, lRectRoot.size.height);
     }
-    DBG_PRINT("CALayer::AddCASublayer0.2: %p . %p %lf/%lf %lfx%lf (refcnt %d)\n", 
-        rootLayer, subLayer, lRectRoot.origin.x, lRectRoot.origin.y, lRectRoot.size.width, lRectRoot.size.height, (int)[subLayer retainCount]);
-
-    [JNFRunLoop performOnMainThreadWaiting:YES withBlock:^(){
-        // simple 1:1 layout !
-        [subLayer setFrame:lRectRoot];
-        [rootLayer addSublayer:subLayer];
-
-        // no animations for add/remove/swap sublayers etc 
-        // doesn't work: [layer removeAnimationForKey: kCAOnOrderIn, kCAOnOrderOut, kCATransition]
-        [rootLayer removeAllAnimations];
-        [rootLayer setAutoresizingMask: (kCALayerWidthSizable|kCALayerHeightSizable)];
-        [rootLayer setNeedsDisplayOnBoundsChange: YES];
-        [subLayer removeAllAnimations];
-        [subLayer setAutoresizingMask: (kCALayerWidthSizable|kCALayerHeightSizable)];
-        [subLayer setNeedsDisplayOnBoundsChange: YES];
-    }];
-    DBG_PRINT("CALayer::AddCASublayer0.X: %p . %p (refcnt %d)\n", rootLayer, subLayer, (int)[subLayer retainCount]);
+    DBG_PRINT("CALayer::AddCASublayer0.2: root %p (refcnt %d) .sub %p %lf/%lf %lfx%lf (refcnt %d)\n", 
+        rootLayer, (int)[rootLayer retainCount],
+        subLayer, lRectRoot.origin.x, lRectRoot.origin.y, lRectRoot.size.width, lRectRoot.size.height, (int)[subLayer retainCount]);
+
+    // simple 1:1 layout !
+    [subLayer setFrame:lRectRoot];
+    [rootLayer addSublayer:subLayer];
+
+    // no animations for add/remove/swap sublayers etc 
+    // doesn't work: [layer removeAnimationForKey: kCAOnOrderIn, kCAOnOrderOut, kCATransition]
+    [rootLayer removeAllAnimations];
+    [rootLayer setAutoresizingMask: (kCALayerWidthSizable|kCALayerHeightSizable)];
+    [rootLayer setNeedsDisplayOnBoundsChange: YES];
+    [subLayer removeAllAnimations];
+    [subLayer setAutoresizingMask: (kCALayerWidthSizable|kCALayerHeightSizable)];
+    [subLayer setNeedsDisplayOnBoundsChange: YES];
+    DBG_PRINT("CALayer::AddCASublayer0.X: root %p (refcnt %d) .sub %p (refcnt %d)\n", 
+        rootLayer, (int)[rootLayer retainCount], subLayer, (int)[subLayer retainCount]);
     JNF_COCOA_EXIT(env);
 }
 
@@ -408,11 +416,12 @@ JNIEXPORT void JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_RemoveCASublayer0
 
     (void)rootLayer; // no warnings
 
-    DBG_PRINT("CALayer::RemoveCASublayer0.0: %p . %p (refcnt %d)\n", rootLayer, subLayer, (int)[subLayer retainCount]);
-    [JNFRunLoop performOnMainThreadWaiting:YES withBlock:^(){
-        [subLayer removeFromSuperlayer];
-    }];
-    DBG_PRINT("CALayer::RemoveCASublayer0.X: %p . %p\n", rootLayer, subLayer);
+    DBG_PRINT("CALayer::RemoveCASublayer0.0: root %p (refcnt %d) .sub %p (refcnt %d)\n", 
+        rootLayer, (int)[rootLayer retainCount], subLayer, (int)[subLayer retainCount]);
+    [subLayer removeFromSuperlayer];
+    [subLayer release];
+    DBG_PRINT("CALayer::RemoveCASublayer0.X: root %p (refcnt %d) .sub %p (refcnt %d)\n", 
+        rootLayer, (int)[rootLayer retainCount], subLayer, (int)[subLayer retainCount]);
     JNF_COCOA_EXIT(env);
 }
 
@@ -427,11 +436,10 @@ JNIEXPORT void JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_DestroyCALayer0
     JNF_COCOA_ENTER(env);
     CALayer* layer = (CALayer*) ((intptr_t) caLayer);
 
-    DBG_PRINT("CALayer::DestroyCALayer0.0: %p (refcnt %d)\n", layer, (int)[layer retainCount]);
-    [JNFRunLoop performOnMainThreadWaiting:YES withBlock:^(){
-        [layer release]; // performs release!
-    }];
-    DBG_PRINT("CALayer::DestroyCALayer0.X: %p\n", layer);
+    DBG_PRINT("CALayer::DestroyCALayer0.0: root %p (refcnt %d)\n", layer, (int)[layer retainCount]);
+    [layer release]; // Var.A
+    // [layer dealloc]; // Var.B -> SIGSEGV
+    DBG_PRINT("CALayer::DestroyCALayer0.X: root %p\n", layer);
     JNF_COCOA_EXIT(env);
 }
 
@@ -450,12 +458,10 @@ JNIEXPORT jboolean JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow
         return JNI_FALSE;
     }
     CALayer* layer = (CALayer*) (intptr_t) caLayer;
-    [JNFRunLoop performOnMainThreadWaiting:YES withBlock:^(){
-        id <JAWT_SurfaceLayers> surfaceLayers = (id <JAWT_SurfaceLayers>)dsi->platformInfo;
-        DBG_PRINT("CALayer::SetJAWTRootSurfaceLayer.0: %p -> %p (refcnt %d)\n", surfaceLayers.layer, layer, (int)[layer retainCount]);
-        surfaceLayers.layer = layer; // already incr. retain count
-        DBG_PRINT("CALayer::SetJAWTRootSurfaceLayer.X: %p (refcnt %d)\n", layer, (int)[layer retainCount]);
-    }];
+    id <JAWT_SurfaceLayers> surfaceLayers = (id <JAWT_SurfaceLayers>)dsi->platformInfo;
+    DBG_PRINT("CALayer::SetJAWTRootSurfaceLayer.0: pre %p -> root %p (refcnt %d)\n", surfaceLayers.layer, layer, (int)[layer retainCount]);
+    surfaceLayers.layer = layer; // already incr. retain count
+    DBG_PRINT("CALayer::SetJAWTRootSurfaceLayer.X: root %p (refcnt %d)\n", layer, (int)[layer retainCount]);
     JNF_COCOA_EXIT(env);
     return JNI_TRUE;
 }
@@ -464,6 +470,7 @@ JNIEXPORT jboolean JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow
  * Class:     Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow
  * Method:    UnsetJAWTRootSurfaceLayer0
  * Signature: (JJ)Z
+ */
 JNIEXPORT jboolean JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow_UnsetJAWTRootSurfaceLayer0
   (JNIEnv *env, jclass unused, jobject jawtDrawingSurfaceInfoBuffer, jlong caLayer)
 {
@@ -474,23 +481,18 @@ JNIEXPORT jboolean JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow
         return JNI_FALSE;
     }
     CALayer* layer = (CALayer*) (intptr_t) caLayer;
-    {
-        id <JAWT_SurfaceLayers> surfaceLayers = (id <JAWT_SurfaceLayers>)dsi->platformInfo;
-        if(layer != surfaceLayers.layer) {
-            NativewindowCommon_throwNewRuntimeException(env, "Attached layer %p doesn't match given layer %p\n", surfaceLayers.layer, layer);
-            return JNI_FALSE;
-        }
+    id <JAWT_SurfaceLayers> surfaceLayers = (id <JAWT_SurfaceLayers>)dsi->platformInfo;
+    if(layer != surfaceLayers.layer) {
+        NativewindowCommon_throwNewRuntimeException(env, "Attached layer %p doesn't match given layer %p\n", surfaceLayers.layer, layer);
+        return JNI_FALSE;
     }
-    // [JNFRunLoop performOnMainThreadWaiting:YES withBlock:^(){
-        id <JAWT_SurfaceLayers> surfaceLayers = (id <JAWT_SurfaceLayers>)dsi->platformInfo;
-        DBG_PRINT("CALayer::detachJAWTSurfaceLayer: (%p) %p -> NULL\n", layer, surfaceLayers.layer);
-        surfaceLayers.layer = NULL;
-        [layer release];
-    // }];
+    DBG_PRINT("CALayer::UnsetJAWTRootSurfaceLayer.0: root %p (refcnt %d) -> nil\n", layer, (int)[layer retainCount]);
+    surfaceLayers.layer = NULL;
+    [layer release]; // Var.A
+    DBG_PRINT("CALayer::UnsetJAWTRootSurfaceLayer.X: root %p (refcnt %d) -> nil\n", layer, (int)[layer retainCount]);
     JNF_COCOA_EXIT(env);
     return JNI_TRUE;
 }
- */
 
 @interface MainRunnable : NSObject
 
@@ -503,6 +505,13 @@ JNIEXPORT jboolean JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow
 - (id) initWithRunnable: (jobject)runnable jvmHandle: (JavaVM*)jvm jvmVersion: (int)jvmVers;
 - (void) jRun;
 
+#ifdef DBG_LIFECYCLE
+- (id)retain;
+- (oneway void)release;
+- (void)dealloc;
+#endif
+
+
 @end
 
 @implementation MainRunnable
@@ -519,20 +528,47 @@ JNIEXPORT jboolean JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow
 {
     int shallBeDetached = 0;
     JNIEnv* env = NativewindowCommon_GetJNIEnv(jvmHandle, jvmVersion, &shallBeDetached);
-    DBG_PRINT("MainRunnable.0 env: %d\n", (int)(NULL!=env));
+    DBG_PRINT2("MainRunnable.1 env: %d\n", (int)(NULL!=env));
     if(NULL!=env) {
-        DBG_PRINT("MainRunnable.1.0\n");
+        DBG_PRINT2("MainRunnable.1.0\n");
         (*env)->CallVoidMethod(env, runnableObj, runnableRunID);
-        DBG_PRINT("MainRunnable.1.1\n");
+        DBG_PRINT2("MainRunnable.1.1\n");
+        (*env)->DeleteGlobalRef(env, runnableObj);
 
         if (shallBeDetached) {
-            DBG_PRINT("MainRunnable.1.2\n");
+            DBG_PRINT2("MainRunnable.1.3\n");
             (*jvmHandle)->DetachCurrentThread(jvmHandle);
         }
     }
-    DBG_PRINT("MainRunnable.X\n");
+    DBG_PRINT2("MainRunnable.X\n");
+}
+
+#ifdef DBG_LIFECYCLE
+
+- (id)retain
+{
+    DBG_PRINT2("MainRunnable::retain.0: %p (refcnt %d)\n", self, (int)[self retainCount]);
+    id o = [super retain];
+    DBG_PRINT2("MainRunnable::retain.X: %p (refcnt %d)\n", o, (int)[o retainCount]);
+    return o;
+}
+
+- (oneway void)release
+{
+    DBG_PRINT2("MainRunnable::release.0: %p (refcnt %d)\n", self, (int)[self retainCount]);
+    [super release];
+    // DBG_PRINT2("MainRunnable::release.X: %p (refcnt %d)\n", self, (int)[self retainCount]);
 }
 
+- (void)dealloc
+{
+    DBG_PRINT2("MainRunnable::dealloc.0 %p (refcnt %d)\n", self, (int)[self retainCount]);
+    [super dealloc];
+    // DBG_PRINT2("MainRunnable.dealloc.X: %p\n", self);
+}
+
+#endif
+
 @end
 
 
@@ -546,11 +582,11 @@ JNIEXPORT void JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_RunOnMainThread0
 {
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
 
-    DBG_PRINT( "RunOnMainThread0: isMainThread %d, NSApp %d, NSApp-isRunning %d\n", 
+    DBG_PRINT2( "RunOnMainThread0: isMainThread %d, NSApp %d, NSApp-isRunning %d\n", 
         (int)([NSThread isMainThread]), (int)(NULL!=NSApp), (int)([NSApp isRunning]));
 
     if ( NO == [NSThread isMainThread] ) {
-        jobject runnableGlob = (*env)->NewGlobalRef(env, runnable);
+        jobject runnableObj = (*env)->NewGlobalRef(env, runnable);
 
         JavaVM *jvmHandle = NULL;
         int jvmVersion = 0;
@@ -561,18 +597,18 @@ JNIEXPORT void JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_RunOnMainThread0
             jvmVersion = (*env)->GetVersion(env);
         }
 
-        DBG_PRINT( "RunOnMainThread0.1.0\n");
-        MainRunnable * mr = [[MainRunnable alloc] initWithRunnable: runnableGlob jvmHandle: jvmHandle jvmVersion: jvmVersion];
+        DBG_PRINT2( "RunOnMainThread0.1.0\n");
+        MainRunnable * mr = [[MainRunnable alloc] initWithRunnable: runnableObj jvmHandle: jvmHandle jvmVersion: jvmVersion];
         [mr performSelectorOnMainThread:@selector(jRun) withObject:nil waitUntilDone:NO];
+        DBG_PRINT2( "RunOnMainThread0.1.1\n");
         [mr release];
-        DBG_PRINT( "RunOnMainThread0.1.1\n");
+        DBG_PRINT2( "RunOnMainThread0.1.2\n");
 
-        (*env)->DeleteGlobalRef(env, runnableGlob);
     } else {
-        DBG_PRINT( "RunOnMainThread0.2\n");
+        DBG_PRINT2( "RunOnMainThread0.2\n");
         (*env)->CallVoidMethod(env, runnable, runnableRunID);
     }
-    DBG_PRINT( "RunOnMainThread0.X\n");
+    DBG_PRINT2( "RunOnMainThread0.X\n");
 
     [pool release];
 }
@@ -644,7 +680,7 @@ JNIEXPORT jint JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_GetScreenRefreshR
     if(0 == res) {
         res = 60; // default .. (experienced on OSX 10.6.8)
     }
-    DBG_PRINT(stderr, "GetScreenRefreshRate.X: %d\n", (int)res);
+    DBG_PRINT("GetScreenRefreshRate.X: %d\n", (int)res);
     // [pool release];
     JNF_COCOA_EXIT(env);
     return res;
diff --git a/src/test/com/jogamp/opengl/test/junit/jogl/awt/TestGLCanvasAddRemove01SwingAWT.java b/src/test/com/jogamp/opengl/test/junit/jogl/awt/TestGLCanvasAddRemove01SwingAWT.java
new file mode 100644
index 000000000..76bb6362f
--- /dev/null
+++ b/src/test/com/jogamp/opengl/test/junit/jogl/awt/TestGLCanvasAddRemove01SwingAWT.java
@@ -0,0 +1,257 @@
+/**
+ * Copyright 2010 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ * 
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ * 
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+ 
+package com.jogamp.opengl.test.junit.jogl.awt;
+
+import java.awt.AWTException;
+import java.awt.BorderLayout;
+import java.awt.Component;
+import java.awt.Container;
+import java.awt.Dimension;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.lang.reflect.InvocationTargetException;
+
+import javax.media.opengl.GLCapabilities;
+import javax.media.opengl.GLProfile;
+import javax.media.opengl.awt.GLCanvas;
+import javax.swing.JFrame;
+import javax.swing.JPanel;
+import javax.swing.SwingUtilities;
+
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import com.jogamp.opengl.test.junit.jogl.demos.gl2.Gears;
+import com.jogamp.opengl.test.junit.util.UITestCase;
+
+public class TestGLCanvasAddRemove01SwingAWT extends UITestCase {
+    static long durationPerTest = 50;
+    static int addRemoveCount = 15;
+    static boolean shallUseOffscreenFBOLayer = false;
+    static boolean shallUseOffscreenPBufferLayer = false;
+    static GLProfile glp;
+    static int width, height;
+    static boolean waitForKey = false;
+
+    @BeforeClass
+    public static void initClass() {
+        if(GLProfile.isAvailable(GLProfile.GL2)) {
+            glp = GLProfile.get(GLProfile.GL2);
+            Assert.assertNotNull(glp);
+            width  = 640;
+            height = 480;
+        } else {
+            setTestSupported(false);
+        }
+    }
+
+    @AfterClass
+    public static void releaseClass() {
+    }
+    
+    protected JPanel createParkingSlot(final JFrame[] top, final int width, final int height) 
+            throws InterruptedException, InvocationTargetException 
+    {
+        final JPanel[] jPanel = new JPanel[] { null };
+        SwingUtilities.invokeAndWait(new Runnable() {
+                public void run() {
+                    jPanel[0] = new JPanel();
+                    jPanel[0].setLayout(new BorderLayout());
+            
+                    final JFrame jFrame1 = new JFrame("Parking Slot");
+                    // jFrame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+                    jFrame1.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE); // equivalent to Frame, use windowClosing event!
+                    jFrame1.getContentPane().add(jPanel[0]);
+                    jFrame1.setSize(width, height);
+                    
+                    top[0] = jFrame1;
+                } } );
+        return jPanel[0];        
+    }
+    
+    protected JPanel create(final JFrame[] top, final int width, final int height, final int num) 
+            throws InterruptedException, InvocationTargetException 
+    {
+        final JPanel[] jPanel = new JPanel[] { null };
+        SwingUtilities.invokeAndWait(new Runnable() {
+                public void run() {
+                    jPanel[0] = new JPanel();
+                    jPanel[0].setLayout(new BorderLayout());
+                    // jPanel[0].add(glcContainer[0], BorderLayout.CENTER);
+                    
+                    // final Container container2 = new Container();
+                    // container2.setLayout(new BorderLayout());
+                    // container2.add(jPanel1, BorderLayout.CENTER);
+            
+                    final JPanel jPanel2 = new JPanel();
+                    jPanel2.setLayout(new BorderLayout());
+                    // jPanel2.add(container2, BorderLayout.CENTER);
+                    jPanel2.add(jPanel[0], BorderLayout.CENTER);
+                    
+                    final JFrame jFrame1 = new JFrame("JFrame #"+num);
+                    // jFrame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+                    jFrame1.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE); // equivalent to Frame, use windowClosing event!
+                    jFrame1.getContentPane().add(jPanel2);
+                    jFrame1.setSize(width, height);
+                    
+                    top[0] = jFrame1;
+                } } );
+        return jPanel[0];        
+    }
+
+    protected void add(final Container cont, final Component comp) 
+            throws InterruptedException, InvocationTargetException 
+    {
+        SwingUtilities.invokeAndWait(new Runnable() {
+                public void run() {
+                    cont.add(comp, BorderLayout.CENTER);                    
+                } } );
+    }
+    
+    protected void remove(final Container cont, final Component comp) 
+            throws InterruptedException, InvocationTargetException 
+    {
+        SwingUtilities.invokeAndWait(new Runnable() {
+                public void run() {
+                    cont.remove(comp);                    
+                } } );
+    }
+    protected void dispose(final GLCanvas glc) 
+            throws InterruptedException, InvocationTargetException 
+    {
+        SwingUtilities.invokeAndWait(new Runnable() {
+                public void run() {
+                    glc.destroy();                    
+                } } );
+    }
+    
+    protected void setVisible(final JFrame jFrame, final boolean visible) throws InterruptedException, InvocationTargetException {
+        SwingUtilities.invokeAndWait(new Runnable() {
+                public void run() {
+                    if( visible ) {
+                        jFrame.validate();
+                        jFrame.pack();
+                    }
+                    jFrame.setVisible(visible);
+                } } ) ;        
+    }
+    
+    protected void dispose(final JFrame jFrame) throws InterruptedException, InvocationTargetException {
+        SwingUtilities.invokeAndWait(new Runnable() {
+                public void run() {
+                    jFrame.dispose();
+                } } ) ;        
+    }
+    
+    protected void runTestGL(GLCapabilities caps, int addRemoveOpCount)
+            throws AWTException, InterruptedException, InvocationTargetException
+    {
+
+        // final JFrame[] parkingFrame = new JFrame[] { null };
+        // final JPanel parkingPanel = createParkingSlot(parkingFrame, 2, 2);
+        
+        for(int i=0; i<addRemoveOpCount; i++) {
+            final GLCanvas glc = new GLCanvas(caps);
+            Assert.assertNotNull(glc);
+            Dimension glc_sz = new Dimension(width, height);
+            glc.setMinimumSize(glc_sz);
+            glc.setPreferredSize(glc_sz);
+            glc.setSize(glc_sz);
+            glc.addGLEventListener(new Gears());
+            glc.setAutoSwapBufferMode(false);
+            // add(parkingPanel, glc);
+            // remove(parkingPanel, glc);
+            
+            final JFrame[] top = new JFrame[] { null };
+            final Container glcCont = create(top, width, height, i);
+            add(glcCont, glc);
+            
+            setVisible(top[0], true);
+                        
+            final long t0 = System.currentTimeMillis();
+            do {
+                glc.display();
+                glc.swapBuffers();
+                Thread.sleep(10);
+            } while ( ( System.currentTimeMillis() - t0 ) < durationPerTest ) ;
+            
+            System.err.println("GLCanvas isOffscreenLayerSurfaceEnabled: "+glc.isOffscreenLayerSurfaceEnabled()+": "+glc.getChosenGLCapabilities());
+            
+            // glc.destroy();
+            dispose(top[0]);            
+        }        
+    }
+
+    @Test
+    public void test01()
+            throws AWTException, InterruptedException, InvocationTargetException
+    {
+        GLCapabilities caps = new GLCapabilities(GLProfile.getDefault());
+        if(shallUseOffscreenFBOLayer) {
+            caps.setOnscreen(false);
+        }
+        if(shallUseOffscreenPBufferLayer) {
+            caps.setPBuffer(true);
+        }
+        runTestGL(caps, addRemoveCount);
+    }
+
+    public static void main(String args[]) throws IOException {
+        for(int i=0; i<args.length; i++) {
+            if(args[i].equals("-time")) {
+                i++;
+                try {
+                    durationPerTest = Integer.parseInt(args[i]);
+                } catch (Exception ex) { ex.printStackTrace(); }
+            } else if(args[i].equals("-loops")) {
+                i++;
+                try {
+                    addRemoveCount = Integer.parseInt(args[i]);
+                } catch (Exception ex) { ex.printStackTrace(); }
+            } else if(args[i].equals("-layeredFBO")) {
+                shallUseOffscreenFBOLayer = true;
+            } else if(args[i].equals("-layeredPBuffer")) {
+                shallUseOffscreenPBufferLayer = true;
+            } else if(args[i].equals("-wait")) {
+                waitForKey = true;
+            }            
+        }
+        System.err.println("shallUseOffscreenFBOLayer     "+shallUseOffscreenFBOLayer);
+        System.err.println("shallUseOffscreenPBufferLayer "+shallUseOffscreenPBufferLayer);
+        if(waitForKey) {
+            BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
+            System.err.println("Press enter to continue");
+            System.err.println(stdin.readLine());
+        }
+        org.junit.runner.JUnitCore.main(TestGLCanvasAddRemove01SwingAWT.class.getName());
+    }
+}
diff --git a/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/awt/TestGearsES2AWT.java b/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/awt/TestGearsES2AWT.java
index 9f62e4a49..048bca982 100644
--- a/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/awt/TestGearsES2AWT.java
+++ b/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/awt/TestGearsES2AWT.java
@@ -63,7 +63,7 @@ public class TestGearsES2AWT extends UITestCase {
     static int width, height;
     static boolean forceES2 = false;
     static boolean forceGL3 = false;
-    static boolean shallUseOffscreenLayer = false;
+    static boolean shallUseOffscreenFBOLayer = false;
     static boolean shallUseOffscreenPBufferLayer = false;
     static boolean useMSAA = false;
     static boolean useStencil = false;
@@ -184,7 +184,7 @@ public class TestGearsES2AWT extends UITestCase {
         if(useStencil) {
             caps.setStencilBits(1);
         }
-        if(shallUseOffscreenLayer) {
+        if(shallUseOffscreenFBOLayer) {
             caps.setOnscreen(false);
         }
         if(shallUseOffscreenPBufferLayer) {
@@ -213,8 +213,8 @@ public class TestGearsES2AWT extends UITestCase {
                 swapInterval = MiscUtils.atoi(args[i], swapInterval);
             } else if(args[i].equals("-exclctx")) {
                 exclusiveContext = true;
-            } else if(args[i].equals("-layered")) {
-                shallUseOffscreenLayer = true;
+            } else if(args[i].equals("-layeredFBO")) {
+                shallUseOffscreenFBOLayer = true;
             } else if(args[i].equals("-layeredPBuffer")) {
                 shallUseOffscreenPBufferLayer = true;
             } else if(args[i].equals("-msaa")) {
@@ -240,7 +240,8 @@ public class TestGearsES2AWT extends UITestCase {
         System.err.println("forceGL3 "+forceGL3);
         System.err.println("swapInterval "+swapInterval);
         System.err.println("exclusiveContext "+exclusiveContext);
-        System.err.println("shallUseOffscreenLayer "+shallUseOffscreenLayer);
+        System.err.println("shallUseOffscreenFBOLayer     "+shallUseOffscreenFBOLayer);
+        System.err.println("shallUseOffscreenPBufferLayer "+shallUseOffscreenPBufferLayer);
         
         if(waitForKey) {
             BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));