src/share/classes/sun/awt/SunToolkit.java

@@ -1618,13 +1618,13 @@
      * <code>true</code> if some events were processed,
      * <code>false</code> otherwise.
      */
     protected abstract boolean syncNativeQueue(final long timeout);
 
-    private boolean eventDispatched = false;
-    private boolean queueEmpty = false;
-    private final Object waitLock = "Wait Lock";
+    private boolean eventDispatched;
+    private boolean queueEmpty;
+    private final Object waitLock = new Object();
 
     private boolean isEQEmpty() {
         EventQueue queue = getSystemEventQueueImpl();
         return AWTAccessor.getEventQueueAccessor().noEvents(queue);
     }

@@ -1637,14 +1637,15 @@
      * necessary, <code>false</code> otherwise.
      */
     @SuppressWarnings("serial")
     protected final boolean waitForIdle(final long timeout) {
         flushPendingEvents();
-        boolean queueWasEmpty = isEQEmpty();
+        final boolean queueWasEmpty;
+        synchronized (waitLock) {
+            queueWasEmpty = isEQEmpty();
         queueEmpty = false;
         eventDispatched = false;
-        synchronized(waitLock) {
             postEvent(AppContext.getAppContext(),
                       new PeerEvent(getSystemEventQueueImpl(), null, PeerEvent.LOW_PRIORITY_EVENT) {
                           public void dispatch() {
                               // Here we block EDT.  It could have some
                               // events, it should have dispatched them by