[hibernate-dev] hibernate-osgi JPA bootstrap & classloader

[Steve Ebersole]

Awesome, thanks!  So I'll investigate BundleListener...

Is that the best way to know when TransactionManagers and DataSources come
and go too?  Or is there a more specific concept for listening to an "OSGi
service"?

Also, do the containers generally handle "in-flight" requests in
regards to TransactionManagers
and DataSources on activated/deactivated?  I guess this is more a
curiosity, since I do not see what we could do if the container does not
manage it.

On Tue, May 26, 2015 at 3:26 PM, Brett Meyer <brmeyer at redhat.com> wrote:

> > I would fully expect hibernate-osgi to not directly use Bootstrap to
> build
> > an EntityManagerFactoryBuilder.  Bootstrap is geared toward users wanting
> > to leverage 2-phase JPA bootstrapping, not our components.  I would have
> > expected Enterprise OSGi support to instead directly build (and possibly
> > override) EntityManagerFactoryBuilderImpl.  I'll add that as a task for
> > post-5.0.
>
> +1, makes sense.  I should have done that to begin with...
>
> > Because I think that is a first step in being able to better
> > manage bundles coming and going.  Please correct me if I am wrong.
>
> At first glance, supporting bundles being activated/deactivated at runtime
> may just be limited to OsgiClassLoader and an impl of OSGi's
> "BundleListener".  HibernateBundleActivator would simply register that
> listener during startup (BundleContext#addBundleListener), which would
> receive the events.  As bundles are added/removed from the runtime, they'd
> just be added/removed from OsgiClassLoader#bundles.
>
> > Also I'd like to start making sure that we fully support (certain) OSGi
> services
> > being replaced.  Especially thinking of TransactionManagers and
> DataSources.
>
> +1
>
> >
> >
> > On Tue, May 26, 2015 at 10:44 AM, Brett Meyer <brmeyer at redhat.com>
> wrote:
> >
> > > IIRC:
> > >
> > > OsgiPersistenceProvider and OsgiSessionFactoryService both need *some*
> way
> > > to build the OsgiClassLoader and pass it into Hibernate
> bootstrapping.  For
> > > the SF, that's easy: just hand OSGiClassLoaderServiceImpl to
> > > BootstrapServiceRegistryBuilder.  For EMF, it looks like I mistakenly
> > > overrode those Bootstrap methods -- I missed that
> PersistenceUnitDescriptor
> > > included the CL.  So you're probably right -- presumably you could
> strip
> > > 'em out and somehow use the descriptor, but you might still need the
> > > overridden method in HibernatePersistenceProvider so that
> > > OsgiPersistenceProvider can give you the OsgiClassLoader to use.
> > >
> > > > Additionally, this ClassLoader is ultimately just used to build the
> > > > ClassLoaderService which hibernate-osgi overrides anyway.
> > >
> > > Right, assuming you're talking about
> > > 'ClassLoaderHelper.overridenClassLoader'.  But the intention there was
> to
> > > remove that whole class ASAP -- that was just a temporary hack for ORM
> 4,
> > > since CL handling was still really static.  But admittedly, I'm a bit
> out
> > > of touch with ORM 5, so I'm not sure if that's feasible yet.
> > >
> > > ----- Original Message -----
> > > > From: "Steve Ebersole" <steve at hibernate.org>
> > > > To: "hibernate-dev" <hibernate-dev at lists.jboss.org>
> > > > Sent: Saturday, May 23, 2015 1:49:50 PM
> > > > Subject: [hibernate-dev] hibernate-osgi JPA bootstrap & classloader
> > > >
> > > > Brett,
> > > >
> > > > As part of HHH-7527 (Enterprise OSGi support) you had changed
> > > > the org.hibernate.jpa.boot.spi.Bootstrap contract to basically
> overload
> > > > each method to additional accept a "providedClassLoader".
> > > >
> > > > Every one of those methods however, also accepts
> > > > a org.hibernate.jpa.boot.spi.PersistenceUnitDescriptor which exposes
> 2
> > > > ClassLoader already.
> > > >
> > > > Additionally, this ClassLoader is ultimately just used to build the
> > > > ClassLoaderService which hibernate-osgi overrides anyway.
> > > >
> > > > Just curious if I missed something.  Unless I did, it seems to me
> that we
> > > > really do not need these overloads on Bootstrap to support Enterprise
> > > > OSGi.  This dove-tails with a discussion from the Karaf user list
> > > > ultimately discussing OsgiClassLoaderService and "holding bundles"
> that
> > > are
> > > > being re-installed or upgraded.  Ultimately I am thinking through
> ways to
> > > > support being able to release OSGI bundle references from the
> > > > OsgiClassLoaderService...
> > > > _______________________________________________
> > > > hibernate-dev mailing list
> > > > hibernate-dev at lists.jboss.org
> > > > https://lists.jboss.org/mailman/listinfo/hibernate-dev
> > > >
> > >
> >
>