A CU faces with deadlock with URLClassLoader.

CONFIGURATION:
OS :
xxxx 116 % uname -a
Linux xxxx 2.6.18-164.11.1.el5 #1 SMP Wed Jan 6 13:26:04 EST 2010 x86
_64 x86_64 x86_64 GNU/Linux

xxxx 117 % more /etc/redhat-release
Red Hat Enterprise Linux Server release 5.4 (Tikanga)

JDK : JDK7b147(32bit)/JDK6u26(32bit)

java version "1.7.0"
Java(TM) SE Runtime Environment (build 1.7.0-b147)
Java HotSpot(TM) Server VM (build 21.0-b17, mixed mode)

java version "1.6.0_26"
Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
Java HotSpot(TM) Server VM (build 20.1-b02, mixed mode)


REPRODUCE:
1. Unfold attached TP2.zip
2. Go to TP2 directory
3. In JDK6ux, launch
      java -javaagent:myagent.jar test2

    In JDK7, launch
      java -XX:+AlwaysLockClassLoader -javaagent:myagent.jar test2


You will see the following message.
<premain>
transform:StartInPremain(sun.misc.Launcher$AppClassLoader@e3a921)
transform:sun/launcher/LauncherHelper(null)
transform:java/lang/Enum(null)
transform:sun/misc/URLClassPath$FileLoader$1(null)
transform:test2(sun.misc.Launcher$AppClassLoader@e3a921)
transform:java/lang/Void(null)
transform:javax/management/MBeanInfo(null)
transform:LoadTarget1(java.net.URLClassLoader@b64078)



4. Open another console, find out the processID, and launch
   "kill -3 <processID>"

You will see an deadlock in the thread dump.
(ex. please see the attached deadlock-log-jdk6u26.txt and
deadlock-log-jdk7b147.txt. )


The CU sent some report of their investigation. Please see the comment section.