AppContext issue in Apple Java 6 -- same issue in Oracle Java 7?

[Doug Zwick]

Here is an example of the deadlocks we were seeing:

"AWT-EventQueue-0" prio=5 tid=0x00007fd234895000 nid=0x9a03 waiting for monitor entry [0x00000001381a9000]
   java.lang.Thread.State: BLOCKED (on object monitor)
        at java.awt.Component.invalidate(Component.java:2916)
        - waiting to lock <0x0000000110335ae8> (a java.awt.Component$AWTTreeLock)
        at java.awt.Container.invalidate(Container.java:1580)
        at javax.swing.JComponent.revalidate(JComponent.java:4851)
        at javax.swing.plaf.basic.BasicTextUI$RootView.preferenceChanged(BasicTextUI.java:1406)
        at javax.swing.text.View.preferenceChanged(View.java:289)
        at javax.swing.text.PlainView.updateDamage(PlainView.java:566)
        at javax.swing.text.PlainView.insertUpdate(PlainView.java:451)
        at javax.swing.text.FieldView.insertUpdate(FieldView.java:293)
        at javax.swing.plaf.basic.BasicTextUI$RootView.insertUpdate(BasicTextUI.java:1602)
        at javax.swing.plaf.basic.BasicTextUI$UpdateHandler.insertUpdate(BasicTextUI.java:1861)
        at javax.swing.text.AbstractDocument.fireInsertUpdate(AbstractDocument.java:202)
        at javax.swing.text.AbstractDocument.handleInsertString(AbstractDocument.java:749)
        at javax.swing.text.AbstractDocument.insertString(AbstractDocument.java:708)
        at javax.swing.text.PlainDocument.insertString(PlainDocument.java:130)
        at javax.swing.text.AbstractDocument.replace(AbstractDocument.java:670)
        at javax.swing.text.JTextComponent.setText(JTextComponent.java:1718)
…

"AWT-EventQueue-1" prio=5 tid=0x00007fd23489d000 nid=0x9d03 waiting for monitor entry [0x00000001384b2000]
   java.lang.Thread.State: BLOCKED (on object monitor)
    at java.awt.Container.getMouseEventTargetImpl(Container.java:2390)
    - waiting to lock <0x0000000110335ae8> (a java.awt.Component$AWTTreeLock)
    at java.awt.Container.getMouseEventTarget(Container.java:2356)
    at java.awt.Container.getMouseEventTarget(Container.java:2319)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4470)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
…

"AWT-EventQueue-2" prio=5 tid=0x00007fd233823000 nid=0x9517 in Object.wait() [0x000000013e023000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on <0x000000012d9c1458> (a javax.swing.text.PlainDocument)
    at java.lang.Object.wait(Object.java:503)
    at javax.swing.text.AbstractDocument.readLock(AbstractDocument.java:1387)
    - locked <0x000000012d9c1458> (a javax.swing.text.PlainDocument)
    at javax.swing.plaf.basic.BasicTextUI.paint(BasicTextUI.java:878)
    at javax.swing.plaf.basic.BasicTextUI.update(BasicTextUI.java:860)
    at javax.swing.JComponent.paintComponent(JComponent.java:778)
    at javax.swing.JComponent.paint(JComponent.java:1054)
    at javax.swing.JComponent.paintChildren(JComponent.java:887)
    - locked <0x0000000110335ae8> (a java.awt.Component$AWTTreeLock)
    at javax.swing.JComponent.paint(JComponent.java:1063)
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5221)
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1508)
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1439)

I'm not sure why AWT-EventQueue-1 seems to be contesting the same AWTTreeLock instance as -0 and -2. AFAIK, we were not getting caught up with the AWT-EventQueue-1 AppContext.

And here is an example of a stack trace from AWT-EventQueue-0 when dispatching an ActionListener.actionPerformed event triggered by the mouse on a screen menu bar menu item:

    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
    at com.apple.laf.ScreenMenuItem.actionPerformed(ScreenMenuItem.java:128)
    at java.awt.MenuItem.processActionEvent(MenuItem.java:669)
    at java.awt.MenuItem.processEvent(MenuItem.java:628)
    at java.awt.MenuComponent.dispatchEventImpl(MenuComponent.java:351)
    at java.awt.MenuComponent.dispatchEvent(MenuComponent.java:339)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:738)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)
    at java.awt.EventQueue$3.run(EventQueue.java:692)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:708)
    at java.awt.EventQueue$4.run(EventQueue.java:706)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

The next frame in that stack trace is our ActionListener.actionPerformed implementation. No deadlocks involved, just calling us back from the wrong EDT.


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