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https://issues.apache.org/jira/browse/JDO-747?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15246555#comment-15246555
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Tilmann Zäschke commented on JDO-747:
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Just to clarify, I think there are something missing from the spec:
The following is already specified for normal {{refresh()}}:
{{PERSISTENT_NONTRANSACTIONAL_DIRTY}} -> {{UNCHANGED}}
{{DETACHED_CLEAN}} -> {{ERROR}}
{{DETACHED_DIRTY}} -> {{ERROR}}
I would suggest that in case an object has been deleted in the DS, the
following transition may be useful (and would be consistent with
{{PERSISTENT_DIRTY}} and {{PERSISTENT_NONTRANSACTIONAL}}):
{{PERSISTENT_NONTRANSACTIONAL_DIRTY}} -> {{TRANSIENT}}
> 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
> Fix For: JDO 3.2
>
> Attachments: JDO-StateTransition-logs-2015-12-04.zip,
> OptimisticCheckConsistency.java, OptimisticFailurePatch_JDO747.txt,
> StateTransitionPatch_JDO747_v4.txt
>
>
> 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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