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

*** 2094,2124 ****
  class PostEventQueue {
      private EventQueueItem queueHead = null;
      private EventQueueItem queueTail = null;
      private final EventQueue eventQueue;
  
      PostEventQueue(EventQueue eq) {
          eventQueue = eq;
      }
  
      public synchronized boolean noEvents() {
!         return queueHead == null;
      }
  
      /*
       * Continually post pending AWTEvents to the Java EventQueue. The method
       * is synchronized to ensure the flush is completed before a new event
       * can be posted to this queue.
       */
!     public synchronized void flush() {
!         EventQueueItem tempQueue = queueHead;
          queueHead = queueTail = null;
          while (tempQueue != null) {
              eventQueue.postEvent(tempQueue.event);
              tempQueue = tempQueue.next;
          }
      }
  
      /*
       * Enqueue an AWTEvent to be posted to the Java EventQueue.
       */
      void postEvent(AWTEvent event) {
--- 2094,2140 ----
  class PostEventQueue {
      private EventQueueItem queueHead = null;
      private EventQueueItem queueTail = null;
      private final EventQueue eventQueue;
  
+     // For the case when queue is cleared but events are not posted
+     private volatile boolean isFlushing = false;
+ 
      PostEventQueue(EventQueue eq) {
          eventQueue = eq;
      }
  
      public synchronized boolean noEvents() {
!         return queueHead == null && !isFlushing;
      }
  
      /*
       * Continually post pending AWTEvents to the Java EventQueue. The method
       * is synchronized to ensure the flush is completed before a new event
       * can be posted to this queue.
+      *
+      * 7177040: The method couldn't be wholly synchronized because of calls
+      * of EventQueue.postEvent() that uses pushPopLock, otherwise it could
+      * potentially lead to deadlock
       */
!     public void flush() {
!         EventQueueItem tempQueue;
!         synchronized (this) {
!             tempQueue = queueHead;
              queueHead = queueTail = null;
+             isFlushing = true;
+         }
+         try {
              while (tempQueue != null) {
                  eventQueue.postEvent(tempQueue.event);
                  tempQueue = tempQueue.next;
              }
          }
+         finally {
+             isFlushing = false;
+         }
+     }
  
      /*
       * Enqueue an AWTEvent to be posted to the Java EventQueue.
       */
      void postEvent(AWTEvent event) {