src/macosx/classes/sun/lwawt/LWLightweightFramePeer.java

@@ -32,10 +32,12 @@
 import java.awt.Window;
 import java.awt.dnd.DropTarget;
 
 import sun.awt.CausedFocusEvent;
 import sun.awt.LightweightFrame;
+import sun.swing.JLightweightFrame;
+import sun.swing.SwingAccessor;
 
 public class LWLightweightFramePeer extends LWWindowPeer {
 
     public LWLightweightFramePeer(LightweightFrame target,
                                   PlatformComponent platformComponent,

@@ -89,15 +91,10 @@
     public void setBounds(int x, int y, int w, int h, int op) {
         setBounds(x, y, w, h, op, true, false);
     }
 
     @Override
-    public void updateCursorImmediately() {
-        // TODO: tries to switch to the awt/fx toolkit thread and causes a deadlock on macosx
-    }
-
-    @Override
     public void addDropTarget(DropTarget dt) {
     }
 
     @Override
     public void removeDropTarget(DropTarget dt) {

@@ -110,6 +107,11 @@
 
     @Override
     public void ungrab() {
         getLwTarget().ungrabFocus();
     }
+
+    @Override
+    public void updateCursorImmediately() {
+        SwingAccessor.getJLightweightFrameAccessor().updateCursor((JLightweightFrame)getLwTarget());
+    }
 }