JDK-6809246 : EventDispatchThread shouldn't be reinitialized for disposed AppContexts
  • Type: Bug
  • Component: client-libs
  • Sub-Component: java.awt
  • Affected Version: 7
  • Priority: P4
  • Status: Closed
  • Resolution: Fixed
  • OS: generic
  • CPU: generic
  • Submitted: 2009-02-24
  • Updated: 2011-07-07
  • Resolved: 2011-07-07
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JDK 7
7 b74Fixed
Related Reports
Relates :  
JDK-6878284 - Sometimes test/javax/swing/system/6799345/TestShutdown.java "hangs"
Description
This issue is reported at java.net forum:

http://forums.java.net/jive/thread.jspa?messageID=333410

Sometimes the following exception is observed in Java Console when applet is being destroyed:

java.lang.IllegalThreadStateException: forbid thread creation in disposed TG
	at sun.plugin.security.ActivatorSecurityManager.checkAccess(Unknown Source)
	at java.lang.ThreadGroup.checkAccess(Unknown Source)
	at java.lang.Thread.init(Unknown Source)
	at java.lang.Thread.<init>(Unknown Source)
	at java.awt.EventDispatchThread.<init>(Unknown Source)
	at java.awt.EventQueue$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.awt.EventQueue.initDispatchThread(Unknown Source)
	at java.awt.EventQueue.postEventPrivate(Unknown Source)
	at java.awt.EventQueue.postEvent(Unknown Source)
	at java.awt.EventQueue.invokeAndWait(Unknown Source)
	at sun.applet.AppletPanel.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)

It's clear that it's thrown when AWT tries to create a new EventDispatchThread instance for disposed AppContext.
Comments
SUGGESTED FIX Webrev for 6878284: http://sa.sfbay.sun.com/projects/awt_data/7/6878284/
17-05-2011
EVALUATION EventQueue.initDispatchThread() has already got a check for threadGroup.isDestroyed(), however it seems to be not enough. Instead, we should check for AppContext.isDisposed() as it's set to true before thread group disposal.
24-02-2009