[SHIRO-544] WeakHashMap 100% CPU utilisation in ShiroModule

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.2.4
• Component/s: Integration: Guice
• Assignee: Jared Bunting
• Reporter: Guillaume Leger
• Created: 29/Sep/15 22:42
• Updated: 29/Sep/15 22:43

Description

ShiroModule's destroyables member variable is backed by an unsynchronized WeakHashMap, which can cause endless loops.

See:

https://java.net/jira/browse/JAVASERVERFACES-2544
https://bugs.eclipse.org/bugs/show_bug.cgi?id=397439

This means that the add(Destroyable) method can cause deadlock.

This issue is hard to workaround because the destroy() method is final so we cannot simply override the behavior.

We were able to fix this problem by making both the add() and destroy() methods synchronized after forking the project.