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https://issues.apache.org/jira/browse/JDO-747?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14902836#comment-14902836
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Tilmann Zäschke commented on JDO-747:
-------------------------------------
What I had in mind is something like this:
{code:title=Bar.java|borderStyle=solid}
PersistenceManagerFactory pmf =
JDOHelper.getPersistenceManagerFactory(props);
//PM 1
PersistenceManager pm1 = pmf.getPersistenceManager();
pm1.currentTransaction().begin();
Person p11 = new Person();
pm1.makePersistent(p11);
Object oid1 = pm1.getObjectId(p11);
pm1.currentTransaction().commit();
//PM 2: concurrent access/modification
PersistenceManager pm2 = pmf.getPersistenceManager();
pm2.currentTransaction().begin();
Person p21 = (Person) pm2.getObjectById(oid1);
//delete Person
pm2.deletePersistent(p21);
//PM1
pm1.currentTransaction().begin();
p11.setName("Alice");
//PM2
pm2.currentTransaction().commit();
pm2.close();
//PM1
try {
pm1.checkConsistency();
fail();
} catch (JDOOptimisticVerificationException e) {
//good!
pm1.refreshAll(e);
}
assertEquals(ObjectState.PERSISTENT_DELETED,
JDOHelper.getObjectState(p11));
pm1.currentTransaction().commit();
pm1.close();
pmf.close();
{code}
As I understand it, currently the {{refreshAll()}} has to fail with
{{JDOObjectNotFound}}. Instead, I think it could mark the object as
{{PERSISTENT_DELETED}} and allow continuing the transaction.
> Behavior of delete() with multiple concurrent Transactions
> ----------------------------------------------------------
>
> Key: JDO-747
> URL: https://issues.apache.org/jira/browse/JDO-747
> Project: JDO
> Issue Type: Improvement
> Components: specification
> Affects Versions: JDO 3.1
> Reporter: Tilmann Zäschke
> Priority: Minor
> Labels: concurrency, delete, documentation, refresh(),
> specification
>
> In the Spec I could not find any statement regarding on how a transaction
> should behave if an object is deleted in a different concurrent transaction.
> Related Sections are Section 5.8 (how different methods should behave for
> different object states) and Section 12.6.1 (the behavior of refresh() and
> related methods).
> For example I wonder about the following situations. Suppose I have two
> optimistic sessions, pm1 and pm2, both access the same object. pm1 deletes
> the object and commits. Then what happens in pm2 if:
> 1. pm2 deletes the object and tries to commit, should that work? It's
> wouldn't be a real conflict if both delete it.
> 2. pm2 modifies the object (make dirty) and calls {{refresh()}}. Should I
> get an {{ObjectNotFound}} exception?
> 3. pm2 deletes the object and calls {{refresh()}}. According to the spec,
> {{refresh()}} should not change the object's state. But should it
> still fail with {{ObjectNotFound}}? If refresh should fail, how can I
> ever recover from such a situation, because I can't undelete the
> object?
> Is there a common understanding how this should work?
> IF there an external definition JDO relies on, then I think a reference to an
> external document might useful.
> If not, should the Spec define concurrent behavior?
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