On 6/5/07, Oliver Zeigermann <[EMAIL PROTECTED]> wrote:
2007/6/5, Alexandru Popescu ☀ <[EMAIL PROTECTED]>:
> On 6/5/07, Oliver Zeigermann <[EMAIL PROTECTED]> wrote:
> > 2007/6/4, Alexandru Popescu ☀ <[EMAIL PROTECTED]>:
> > > On 6/4/07, Oliver Zeigermann <[EMAIL PROTECTED]> wrote:
> > > > I am not deeply into the problem, but why is there locking on the Java
> > > > side anyway? It really should be possible to get along with DB locks
> > > > only.
> > > >
> > > > Calling the DB from synchronized blocks always bears the danger of
deadlocks.
> > > >
> > >
> > > Basically because the implementation of JCR is not required to work on
> > > top of a RDBMS. Moreover, the persistence managers have been usually
> > > created to be used over different persistence solutions (and over
> > > different RDBMS, which have different locking support/mechanisms).
> >
> > If that is so, concurrency code really should be inside the individual
> > persistence solutions and not inside the Jackrabbit core. If it is,
> > there always is a deadlock hazard.
> >
>
> It is. Maybe before going further you should check the code. If you
> have some suggestions I guess everybody would be happy to hear about
> different approaches.
Oh. Sorry for being ignorant :(
No worries. But I am not a Jackrabbit developer, so sometimes I may be
mistaking.
It would be great if you could help me getting smarter. Two questions
(1) Why is there Java side locking in the BundleDbPersistenceManager anyway?
I don't know the details of BundleDbPersistenceManager. However, this
question (or the more generic one about PMs) has been discussed
extensively in the past on the ml, so a search will reveal lots of
answers (I think Steffan is the guy)
(2) If all locking is inside the individual persistence managers, what
is the purpose of SharedItemStateManager locking?
Think about SharedItemStateManger as a 2nd level cache. A cache
without correct synchronization would not be a real cache. Basically,
it is meant to fulfill the spec requirements about item visibility
between different sessions.
bests,
./alex
--
.w( the_mindstorm )p.
Thanks in advance
Oliver
