guice-servlet+guice-persist -- Memory leak

_From [m.zabel.92](https://code.google.com/u/113275355068145543288/) on August 28, 2013 07:58:42_

When a simple guice servlet application is created, e.g. following the example in the wiki ( https://code.google.com/p/google-guice/wiki/ServletModule ), it can be deployed and redeployed several times without problems.

With the usage of guice-persist a memory leak occurs. This happens as soon as the following two lines are added to the configuration class:

install(new JpaPersistModule("name"));
filter("/*").through(PersistFilter.class);

On a running application server (tested with Tomcat) multiple redeploys result in a PermGen exception.

As a profiler reveals, several instances of Guice's own classes cannot be garbage collected after undeployment.

This was tested with guice version 4.0-beta and 3.0.

_Original issue: http://code.google.com/p/google-guice/issues/detail?id=768_