ingrid.yao@Eng 1997-08-06

Oracle report the deadlock problem:
==============================================================
Have a look at the sequence of methods calls in the two deadlocked threads;
"Forms-Runform-1" and "AWT-EventQueue-0":

sun.applet.AppletClassLoader.getThreadGroup is synchronized , so the
"Forms-Runform-1" thread is waiting for the AppletClassLoader object's monitor, which is held by the "AWT-EventQueue-0" thread.

sun.applet.AppletSecurity.checkRead is synchronized, so the "AWT-EventQueue-0"
thread is waiting for the AppletSecurity object's monitor, which is held by the
"Forms-Runform-1" thread.

Each thread is blocked waiting for a monitor held by the other thread, so we have a deadlock.

Here is the stack trace and the monitor state with the irrelevant parts removed:

    "Forms-Runform-1" (TID:0xf653b0, sys_thread_t:0x874580, Win32ID:0x94, stat4
        sun.applet.AppletClassLoader.getThreadGroup(AppletClassLoader.java:597)
        sun.applet.AppletSecurity.inThreadGroup(AppletSecurity.java:184)
        sun.applet.AppletSecurity.checkAccess(AppletSecurity.java:214)
        java.lang.ThreadGroup.checkAccess(ThreadGroup.java:271)
        java.lang.Thread.init(Thread.java:261)
        java.lang.Thread.<init>(Thread.java:393)
        oracle.ewt.timer.Timer.<init>(Timer.java:35)
        oracle.ewt.timer.Periodic.<init>(Periodic.java:28)
        oracle.ewt.lwAWT.lwText.CursorIdler.<init>(CursorIdler.java:38)
        oracle.ewt.lwAWT.lwText.CursorIdler.getCursorIdler(CursorIdler.java:50)
        oracle.ewt.lwAWT.lwText.LWTextComponent.addNotify(LWTextComponent.java)
        java.awt.Container.addNotify(Container.java:1083)
        oracle.forms.uiClient.v1_4.ui.DrawnPanel.addNotify(DrawnPanel.java:447)
        java.awt.Container.addNotify(Container.java:1083)
        java.awt.Container.addNotify(Container.java:1083)
        java.awt.Container.addNotify(Container.java:1083)
        oracle.forms.uiClient.v1_4.ui.DrawnPanel.addNotify(DrawnPanel.java:447)
        java.awt.Container.addNotify(Container.java:1083)
        java.awt.Container.addNotify(Container.java:1083)
        java.awt.Container.addNotify(Container.java:1083)

    "AWT-EventQueue-0" (TID:0xf5ac08, sys_thread_t:0x872d90, Win32ID:0x8b, sta5
        sun.applet.AppletSecurity.checkRead(AppletSecurity.java:436)
        java.io.FileInputStream.<init>(FileInputStream.java:103)
        java.net.SocketInputStream.<init>(SocketInputStream.java:50)
        java.net.PlainSocketImpl.getInputStream(PlainSocketImpl.java:394)
        java.net.Socket.getInputStream(Socket.java:290)
        sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:484)
        sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConn)
        sun.applet.AppletClassLoader.loadClass(AppletClassLoader.java:119)
        sun.applet.AppletClassLoader.findClass(AppletClassLoader.java:494)
        sun.applet.AppletClassLoader.loadClass(AppletClassLoader.java:197)
        java.lang.ClassLoader.loadClassInternal(ClassLoader.java:313)
        oracle.ewt.lwAWT.SharedPainter.paint(SharedPainter.java:323)
        oracle.ewt.lwAWT.BufferedFrame.paint(BufferedFrame.java:281)
        oracle.ewt.lwAWT.BufferedFrame.update(BufferedFrame.java:268)
        oracle.forms.uiClient.v1_4.ui.ExtendedFrame.update(ExtendedFrame.java:)
        java.awt.Component.dispatchEventImpl(Component.java:1714)
        java.awt.Container.dispatchEventImpl(Container.java:897)
        java.awt.Window.dispatchEventImpl(Window.java:443)
        java.awt.Component.dispatchEvent(Component.java:1693)
        java.awt.EventDispatchThread.run(EventDispatchThread.java:63)

Monitor Cache Dump:
    sun.applet.AppletSecurity@F56D08/FA8958: owner "Forms-Runform-1" (0x874580)
    sun.applet.AppletClassLoader@F59D48/FB9420: owner "AWT-EventQueue-0" (0x87)


If you walk up the stack examining each method in turn, you can see that:

- The AppletSecurity object's monitor is grabbed by the "Forms-Runform-1"
  thread in sun.applet.AppletSecurity.checkAccess, because it is synchronized

- The AppletClassLoader object's monitor is grabbed by the "AWT-EventQueue-0"
  thread in sun.applet.AppletClassLoader.findClass, because it is synchronized.