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https://issues.apache.org/jira/browse/OPENJPA-258?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Patrick Linskey updated OPENJPA-258:
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Fix Version/s: 1.1.0
> MetaDataInheritanceComparator is not transitive; C > B > A > C leads to
> out-of-memory crash in PCEnhancer
> ---------------------------------------------------------------------------------------------------------
>
> Key: OPENJPA-258
> URL: https://issues.apache.org/jira/browse/OPENJPA-258
> Project: OpenJPA
> Issue Type: Bug
> Components: jpa
> Affects Versions: 0.9.6
> Environment: Sun JDK 5, Sun JDK 6
> Reporter: Jonathan Feinberg
> Priority: Blocker
> Fix For: 1.0.2, 1.1.0
>
> Attachments: jpa-comparator-bug.zip
>
>
> Comparisons done by MetaDataInheritanceComparator are not transitive. It is
> possible to have classes A, B, and C such that the comparator simultaneously
> reports that A > B, B > C, and C > A. Under certain unlucky conditions, this
> causes the SortedTree holding the metadata resolution buffer to become
> confused during Red-Black fix, such that it can retrieve a certain element,
> but not delete it. The "processed" list then grows until heap is exhausted.
> In the enclosed sample project,
> A < B by name
> B < C by assignable primary key field
> C < A by "levels" from base class (Object)
> If you import the enclosed eclipse project into an AspectJ-enabled eclipse,
> and refer the AspectJ compiler to an OpenJPA jar file, you'll get the
> following output:
> bug.B > bug.A
> bug.C > bug.B
> bug.A > bug.C
> Cycle detected:
> bug.A > bug.C > bug.B > bug.A
> The project will work outside of AspectJ, and will exhibit the out of memory
> condition described above.
> I acknowledge that the enclosed persistence.xml file is not kosher, in that
> it doesn't list all classes to be instrumented. My own project, affected by
> this bug, has a correct persistence.xml file. I had to work hard to contrive
> a simple example, as the order in which classes are buffered affects the
> appearance of the bug.
> There is no work-around that I know of. I don't believe that the comparator's
> semantics are well-defined.
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