[MNG-5589] Investigate how plugin classloaders are shutdown

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.2.1
• Fix Version/s: 4.x / Backlog
• Assignee: Unassigned
• Reporter: Jason van Zyl
• Created: 14/Feb/14 10:13
• Updated: 23/Dec/19 12:22

Description

http://www.mail-archive.com/[e-mail]/msg99645.html

Stuart's analysis of the above thread:
I suspect this is related to the change in Classworlds 2.4.1+ to use the
new ClassLoader.close() method available in Java7 to forcibly close plugin
ClassLoaders when the plugin/container realm is disposed. This happens
after the Maven build is finished, but before JVM shutdown hooks run.

Any plugin that registers a JVM shutdown hook which tries to load
classes/resources from the original plugin realm will throw a NCDFE -
you'll probably see similar issues if a plugin forks threads that are still
running after the plugin/container realm has been disposed and subsequently
try to load classes.

( note that the same error will likely occur with Maven 3.1.1 since it uses
the same version of Classworlds )