Description of problem:
When shutting down the server, the following error is logged and the server hangs during shutdown:

    ERROR [STDERR] Exception in thread "AWT-Windows" 
    ERROR [STDERR] java.lang.IllegalStateException: Shutdown in progress
    ERROR [STDERR] 	at java.lang.ApplicationShutdownHooks.add(Unknown Source)
    ERROR [STDERR] 	at java.lang.Runtime.addShutdownHook(Unknown Source)
    ERROR [STDERR] 	at sun.awt.windows.WToolkit$2.run(Unknown Source)
    ERROR [STDERR] 	at java.security.AccessController.doPrivileged(Native Method)
    ERROR [STDERR] 	at sun.awt.windows.WToolkit.run(Unknown Source)
    ERROR [STDERR] 	at java.lang.Thread.run(Unknown Source)

The result is that the JVM process does not exit on its own. Instead, the java.exe process must be terminated or if the Java Service Wrapper was used to launch the server, wait for its wrapper.jvm_exit.timeout value to expire (which by default is 180 seconds). However, even then the JVM is not being shutdown properly/cleanly.


Version-Release number of selected component (if applicable):
4.4.0.JON311GA

How reproducible:
Always

Steps to Reproduce:
1.  Install Windows Server 2008
2.  Install PostgreSQL database
3.  Initialize RHQ PostgreSQL role and database

    createuser -U postgres -SRD rhqadmin
    createdb -U postgres -O rhqadmin rhq
    psql -U postgres -c "ALTER USER rhqadmin WITH PASSWORD 'rhqadmin';"

4.  Install Java 6 32-bit JRE

    This is required because JBoss ON on Windows can only run as a service in a 32-bit JRE due to us using a third-party service wrapper.
    
5.  Install JBoss ON 3.1.1 server using rhq-server console
6.  After configured and installed, from the terminal windows where rhq-server console was executed, issue CTRL-C
  

Actual results:
Server log contains the following exception and JVM doesn't shutdown until the Java Service Wrapper kills it 3 minuts later.
    ERROR [STDERR] Exception in thread "AWT-Windows" 
    ERROR [STDERR] java.lang.IllegalStateException: Shutdown in progress
    ERROR [STDERR] 	at java.lang.ApplicationShutdownHooks.add(Unknown Source)
    ERROR [STDERR] 	at java.lang.Runtime.addShutdownHook(Unknown Source)
    ERROR [STDERR] 	at sun.awt.windows.WToolkit$2.run(Unknown Source)
    ERROR [STDERR] 	at java.security.AccessController.doPrivileged(Native Method)
    ERROR [STDERR] 	at sun.awt.windows.WToolkit.run(Unknown Source)
    ERROR [STDERR] 	at java.lang.Thread.run(Unknown Source)


Expected results:
Server should shutdown as normal and no execption should be logged and JVM should not hang.


Additional info:
This appears to be a result of statically initializing AWT from org.rhq.enterprise.gui.image.WebImage. Part of this may be a bug in AWT and its inability to understand that a shutdown is already underway (i.e. it doesn't handle the exception thrown and simply waits). However, to prevent it, it is recommended that the graphics library is loaded when needed instead of statically in the class loader.

One possible workaround for this issue is to use the following JVM argument to force Tomcat not to free up static classes:

    -Dorg.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES=false
    
The down-side to this is that memory leaks will be introduced in the event that classes are unloaded/reloaded which use thes static references.