Module system notification mechanism

[Stanley M. Ho]

Hi Bryan,

Bryan Atsatt wrote:
> As long as there is some API support for disabling the loader, I'm fine
> with this approach.

Good.

> However, this is not a feature I would ever advocate adding to
> java.lang.ClassLoader(!), since it really only makes sense in the
> context of a managed loader. In a managed environment with a true
> lifecycle, it is important to be able to *find* ongoing uses of a
> supposedly stopped module. The only way we've ever been able to do that
> is to ensure that any use of such a loader will cause an exception to be
> thrown.
>
> We have had great success with this model in finding code that does not
> participate correctly in the container lifecycle. The most common case
> is threads that aren't stopped when they should be. Leaked references
> are another huge headache.

I also don't think it should be in java.lang.ClassLoader, but we should
leave it up to the classloading folks to decide. In case the
functionality ends up in a public API in a vendor specific package (e.g.
com.sun.* or something similar), I think this should still work for you.

- Stanley