Memory leak in com.sun.jndi.ldap.pool.PoolCleaner

[Mark Thomas]

Hi,

While working my way through Tomcat's memory leak protection / detection
/ fixing code, I have found an issue that remains unresolved in the
latest JDK 9 source.

The PoolCleaner thread started by the LdapPoolManager when the idle
timeout is positive does not explicitly set the context class loader so
it inherits the current context class loader. If the current context
class loader when this code is triggered happens to be one that is meant
to be disposable (e.g. a web application class loader) the class loader
will be pinned in memory until the Thread stops. This prevents the class
loader from being GC'd when no longer required and triggers a mmeory leak.

The fix looks to be trivial. Something along the lines of the following
around line 45 of PoolCleaner:

setContextClassLoader(PoolCleaner.class.getClassLoader());

If I can provide any further information or if there is better place /
way to submit this then please do let me know.

Mark