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https://issues.apache.org/jira/browse/OPENJPA-2051?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Heath Thomann closed OPENJPA-2051.
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> Entities in a relationship are not properly cascaded after a
> EntityManager.flush is executed.
> ---------------------------------------------------------------------------------------------
>
> Key: OPENJPA-2051
> URL: https://issues.apache.org/jira/browse/OPENJPA-2051
> Project: OpenJPA
> Issue Type: Bug
> Affects Versions: 2.0.0, 2.1.1, 2.2.0
> Reporter: Heath Thomann
> Assignee: Heath Thomann
> Priority: Minor
> Fix For: 1.2.3, 2.0.2, 2.1.2, 2.2.0
>
> Attachments: CascadePersistIssue.test.patch
>
>
> I've found a scenario where upon transaction commit, certain entities which
> should be persisted via a cascade operation are not present in the database.
> To properly describe this issue, let me start by first introducing a few
> entities, and then list a snippet of a test which uses these entities to
> recreate an issue with cascading entities. That said, take the following
> three entities:
> public class Vertex {
> @Id
> @GeneratedValue(strategy = GenerationType.AUTO)
> private long oid;
> @OneToMany(mappedBy = "source", cascade = CascadeType.ALL)
> private List<Edge> outgoing;
> @OneToMany(mappedBy = "target", cascade = CascadeType.ALL)
> private List<Edge> incoming;
> @ManyToOne(cascade = CascadeType.ALL)
> @JoinColumn(name = "TYPE_OID")
> private VertexType type;
> public Edge newEdge( Vertex target ) {
> Edge t = new Edge( this );
> outgoing.add( t );
> t.setTarget( target );
> return t;
> }
> .........
> public class VertexType {
> @Id
> @GeneratedValue(strategy = GenerationType.AUTO)
> private long oid;
> @OneToMany(mappedBy = "type", cascade = CascadeType.ALL)
> List<Vertex> instances;
> private String name;
> .........
> public class Edge {
> @Id
> @GeneratedValue(strategy = GenerationType.AUTO)
> private long oid;
> @ManyToOne(cascade = CascadeType.ALL)
> @JoinColumn(name = "SOURCE_OID")
> private Vertex source;
> @ManyToOne(cascade = CascadeType.ALL)
> @JoinColumn(name = "TARGET_OID")
> private Vertex target;
> .........
> Before describing the test case, let me point out a couple important things
> about these entities. First you will notice that each entity contains a
> generated id. Second, notice that there are multiple relationships between
> these entities.
> Now let me introduce the test:
> EntityManager em = emf.createEntityManager();
> EntityTransaction tx = em.getTransaction();
> tx.begin();
> em.flush();
> VertexType defaultType = new VertexType( "default" );
> VertexType specialType = new VertexType( "special" );
> em.persist(defaultType);
> em.persist(specialType);
> Vertex src = new Vertex( defaultType );
> Vertex target = new Vertex( specialType );
> Edge t = src.newEdge( target );
> assertNotNull( t );
> em.persist(src);
> tx.commit();
> Notice that one of the first things the test does is to perform a flush.
> This may seem slightly odd, however this flush is important to cause the
> issue. We could execute a query or some other operation which would cause a
> flush under the covers, however, calling a flush directly makes it clear that
> a flush has occurred when looking at the rest of the test.
> With the entities and test case in place, let me now describe the issue.
> After this test case executes, there should exist in the database two Vertex,
> two VertexType, and one Edge given the cascade type defined in the entities.
> However, I find that one of the Vertex is missing.
> In working with Rick Curtis on this issue, he found that the 'flush' at the
> beginning of the test had an effect on the cascade persist at the end of the
> test. That is, when 'flush' is called, this causes the '_flags' variable in
> BrokerImpl to be set to flushed as follows:
> _flags |= FLAG_FLUSHED;
> This of course effects the return value of the method BrokerImpl.hasFlushed:
> private boolean hasFlushed() {
> return (_flags & FLAG_FLUSHED) != 0;
> }
> I will now describe how the return value of this method effects the outcome
> of the test. However, in an effort of time I am going to skip over some
> details which I'll leave as an exercise for the reader to figure out (e.g.
> execute the test in a debugger). Basically this has an effect on
> SingleFieldManager.persist when called by StateManagerImpl.cascadePersist.
> That is, SingleFieldManager.persist makes a call to method 'isDetached' on
> the broker here:
> case JavaTypes.PC_UNTYPED:
> if (!_broker.isDetachedNew() && _broker.isDetached(objval))
> return; // allow but ignore
> _broker.persist(objval, true, call);
> break;
> Code within 'isDetached' eventually makes a call to 'hasFlushed'. Given that
> 'hasFlushed' returns true, it ultimately effects the result of 'isDetached'
> and thus causing the persist method in the previously posted code block to be
> skipped. Again, I'm glossing over some details, but the code path described
> is also affected by the fact that the ids in these entities are auto
> generated.
> In order to resolve this problem, we feel the best solution is to change the
> '_flags' variable to indicate a flush has not occurred. To that end, we
> propose adding the assignment '_flags &= ~FLAG_FLUSHED'
> to this portion of code in BrokerImpl.setStateManager:
> case STATUS_INIT:
> _flags &= ~FLAG_FLUSHED;
> _cache.add(sm);
> break;
> In addition, this new assignment will be gated by a compatibility property.
> I've included a test patch, named 'CascadePersistIssue.test.patch' which
> replicates the issue.
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