ClassFactory constructor cache could be more efficient

[Tomas-Kraus]

ClassFactory currently uses a ThreadLocal Map<Class,Constructor> in order to cache the default constructor lookups used in unmarshalling.

issues:

• The Cache is only valid with the current thread, thus each thread (possibly hundreds in an app server) has to populate it's own cache
• Use of ThreadLocal's within an application server can lead to ClassLoader leaks, as each Thread can retain a reference to a ThreadLocal even though it is unreachable

The common solution to the ThreadLocal issue is to call ClassFactory.clearCache() in a Servlet filter or similar which removes the ThreadLocal map.

I propose (see mailing list for patch) that the cache can be implemented using a non locking copy on write algorithm that would will be the same or very close performance with a much reduced memory overhead (once populated) and better hit ratio.

Affected Versions

[not determined]

[Tomas-Kraus]

• Issue Imported From: https://github.com/javaee/jaxb-v2/issues/979
• Original Issue Raised By:@glassfishrobot
• Original Issue Assigned To: @glassfishrobot

[Tomas-Kraus]

@glassfishrobot Commented Reported by gadavis

[Tomas-Kraus]

@glassfishrobot Commented Was assigned to yaroska

[Tomas-Kraus]

@glassfishrobot Commented This issue was imported from java.net JIRA JAXB-979