Project proposal: Remove the Permanent Generation

Florian Weimer fweimer at
Mon Nov 28 10:14:59 PST 2011

* Jon Masamitsu:

> I am going to be proposing the permanent generation
> removal as  a OpenJDK project shortly.  The project is
> described in the JEP 122
> This is not the formal proposal of the project but rather
> a chance to ask questions ahead of that proposal.

Interned strings have already been moved out of the permanent

changeset:   2226:b099aaf51bf8
user:        jcoomes
date:        Tue Mar 22 13:36:33 2011 -0700
summary:     6962931: move interned strings out of the perm gen

This is in jdk7u2 (and perhaps earlier).

How does the PermGen removal interact with anonymous classes (that is,
classes whose metadata can be reclaimed individually, while the
corresponding class loader still exists)?  I'm not sure what happened to
anonymous classes; originally, this was one of the features in JDK 7
targeted at dynamic languages.  But if they still need to be supported,
then this might complicate managing meta-data stored in the C heap.

Florian Weimer                <fweimer at>
BFK edv-consulting GmbH
Kriegsstraße 100              tel: +49-721-96201-1
D-76133 Karlsruhe             fax: +49-721-96201-99

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