Re: [JBoss-user] Application deadlock detected.

[Adrian B. <wa...@ho...>]

It sounds like you don't want to use
full pessimistic transactional locking.
Nested transactions are not supported by jboss.

In your case the entity is locked to the
first transcation so the second transaction
cannot get access.

One solution is not to lock the entity on "reads"
Specify something like the following in jboss.xml
for the bean.
<method-attributes>
  <method>
     <method-name>get*</method-name>
     <read-only>true</read-only>
  </method>
</method-attributes>

You will find a more complete explanation
and other solutions in the for pays docs
or by searching the forums.

Regards,
Adrian

>From: Jon Haugsand <Jon...@no...>
>Reply-To: jbo...@li...
>To: jbo...@li...
>Subject: Re: [JBoss-user] Application deadlock detected.
>Date: 21 Mar 2003 17:43:09 +0100
>
>* Jon Haugsand
> > When porting an application from weblogic to JBoss, the following
> > failure took place:
> >
> >   Application deadlock detected: Current thread already has tx lock in
> >   different transaction.
>
>I found out what happened, here is a sketch:
>
>1 Transaction begins
>2    Entity bean instance is read
>3    Transaction begins
>4       Same entity bean instance is read
>5       Instance is changed
>6    Transaction ends
>7    More action
>8 Transaction ends
>
>JBoss does not like this behaviour as we get a dead lock detection at
>line 4.  Weblogic does not complain.  Can anyone tell me what can
>possible go wrong here (I mean appart from JBoss's dead lock
>detection)?
>
>(I do not like the nested transactions, but it allegedly was needed to
>resolve a similar dead lock situation in the Weblogic.)
>
>How do you attack such situations anyway?
>
>--
>  Jon Haugsand, Jon...@no...
>  http://www.norges-bank.no
>
>
>
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