Made Refernced::setThreadSafeReferenceCounting(bool) a virtual then overrode

this in various scene graph classes to ensure that the scene graph gets
updated as well as the objects that the initialial call is made from.

src/osgViewer/GraphicsWindowX11.cpp

@@ -585,6 +585,8 @@ void GraphicsWindowX11::closeImplementation()
 
         XFlush( _display );
         XSync( _display,0 );
+
+        XCloseDisplay( _display );
     }
 
     _window = 0;
@@ -626,6 +628,7 @@ void GraphicsWindowX11::checkEvents()
     int windowWidth = _traits->width;
     int windowHeight = _traits->height;
 
+    bool destroyWindowRequested = false;
      
          // osg::notify(osg::NOTICE)<<"Check events"<<std::endl;    
     while( XPending(_display) )
@@ -640,7 +643,7 @@ void GraphicsWindowX11::checkEvents()
                 if (static_cast<Atom>(ev.xclient.data.l[0]) == _deleteWindow)
                 {
                     osg::notify(osg::INFO)<<"DeleteWindow event recieved"<<std::endl;
-                    close();
+                    destroyWindowRequested = true;
                 }
             }
             case Expose :
@@ -842,6 +845,12 @@ void GraphicsWindowX11::checkEvents()
         resized(windowX, windowY, windowWidth, windowHeight); 
         getEventQueue()->windowResize(windowX, windowY, windowWidth, windowHeight);
     }
+
+    if (destroyWindowRequested)
+    {
+        close();
+    }
+
 }
 
 void GraphicsWindowX11::grabFocus()

src/osgViewer/View.cpp

@@ -22,7 +22,11 @@ using namespace osgViewer;
 View::View()
 {
     // osg::notify(osg::NOTICE)<<"Constructing osgViewer::View"<<std::endl;
-   setEventQueue(new osgGA::EventQueue);
+
+    // make sure View is safe to reference multi-threaded.
+    setThreadSafeRefUnref(true);
+
+    setEventQueue(new osgGA::EventQueue);
 }
 
 View::~View()

src/osgViewer/Viewer.cpp

@@ -158,7 +158,19 @@ void Viewer::startThreading()
         stopThreading();
     }
 
-    osg::notify(osg::INFO)<<"Viewer::startThreading() - starting threading"<<std::endl;
+    // using multi-threading so make sure that new objects are allocated with thread safe ref/unref
+    osg::Referenced::setThreadSafeReferenceCounting(true);
+    
+    if (getSceneData())
+    {
+        // make sure that existing scene graph objects are allocated with thread safe ref/unref
+        getSceneData()->setThreadSafeRefUnref(true);
+        
+        // update the scene graph so that it has enough GL object buffer memory for the graphics contexts that will be using it.
+        getSceneData()->resizeGLObjectBuffers(osg::DisplaySettings::instance()->getMaxNumberOfGraphicsContexts());
+    }
+
+    osg::notify(osg::NOTICE)<<"Viewer::startThreading() - starting threading"<<std::endl;
 
     Contexts contexts;
     getContexts(contexts);
@@ -320,7 +332,6 @@ void Viewer::realize()
         ++citr)
     {
         (*citr)->realize();
-//        OpenThreads::Thread::YieldCurrentThread();
     }
     
     bool grabFocus = true;
@@ -336,8 +347,9 @@ void Viewer::realize()
                 gw->grabFocusIfPointerInWindow();    
             }
         }
-    }            
-
+    }
+    
+    
     startThreading();
 
     // initialize the global timer to be relative to the current time.