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Bug 364442

Summary: NPE caused by concurrent usage of Query.setHint on named query with join-fetch/batch
Product: z_Archived Reporter: Sven Hoffmann <sven.hoffmann>
Component: EclipselinkAssignee: Nobody - feel free to take it <nobody>
Status: CLOSED FIXED QA Contact:
Severity: critical    
Priority: P2 CC: andrei.ilitchev, tom.ware
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: other   
Whiteboard:
Attachments:
Description Flags
Stacktrace of NullPointerException
none
Suggested patch (for trunk)
none
Test fix - the test should not run on app. server none

Description Sven Hoffmann CLA 2011-11-22 02:44:03 EST 
Build Identifier: 2.3.1.v20111014-r10236

As described in "NullPointerException in Query.setHint with join-fetch/batch" (http://www.eclipse.org/forums/index.php/t/262488) a NullPointerException occurs while using Query.setHint on a named query with join-fetch/batch.

The code performing the query looks like:
Query query = em.createNamedQuery(Container.LOAD_BY_ORDER);
query.setParameter("orderId", id);
query.setHint(QueryHints.FETCH, "c.attribute1");
query.setHint(QueryHints.BATCH, "c.attribute3");
List result = query.getResultList();

The application uses EclipseLink 3.2.1 M8 and is hosted on WebSphere Application Server 7.0 FP17 on an AIX system. The query is concurrently performed by message driven beans.
After one failure all subsequent calls fail with the same exception until the server is restarted.

It should be possible to execute the code above concurrently without getting a NullPointerException.



Reproducible: Sometimes

Steps to Reproduce:
Concurrent calls of Query.setHint on named query with join-fetch/batch.
Comment 1 Sven Hoffmann CLA 2011-11-22 02:45:11 EST 
Created attachment 207346 [details]
Stacktrace of NullPointerException
Comment 2 Tom Ware CLA 2011-11-22 07:44:41 EST 
Please describe the level of concurrency (i.e. what is shared between threads?)

Is it the EntityManager?  The EntityManagerFactory?  The query?
Comment 3 Sven Hoffmann CLA 2011-11-22 07:52:13 EST 
(In reply to comment #2)
> Please describe the level of concurrency (i.e. what is shared between threads?)
> 
> Is it the EntityManager?  The EntityManagerFactory?  The query?
The application (stateful session bean) shares none of these.

James in http://www.eclipse.org/forums/index.php/mv/msg/262488/758040/#msg_758040
> The issue is although the hint causes different queries to be used, the same expression is still used, causing the concurrency issue.
As far as I understood James in the related post the expression of the named query is internally shared between threads.
Comment 4 Tom Ware CLA 2011-12-02 10:25:39 EST 
Setting target and priority.  See the following page for the meanings of these fields:

http://wiki.eclipse.org/EclipseLink/Development/Bugs/Guidelines

Community: Please vote for this bug if it is important to you.  Votes are one of the main criteria we use to determine which bugs to fix next.
Comment 5 Andrei Ilitchev CLA 2012-03-06 17:23:35 EST 
Created attachment 212173 [details]
Suggested patch (for trunk)
Comment 6 Andrei Ilitchev CLA 2012-03-07 10:45:41 EST 
The patched checked into both trunk and 2.3.3.
Comment 7 Andrei Ilitchev CLA 2012-03-08 10:46:47 EST 
Created attachment 212300 [details]
Test fix - the test should not run on app. server
Comment 8 Andrei Ilitchev CLA 2012-03-08 10:54:32 EST 
The patched checked into both trunk and 2.3.3.
Comment 9 Eclipse Webmaster CLA 2022-06-09 10:29:27 EDT 
The Eclipselink project has moved to Github: https://github.com/eclipse-ee4j/eclipselink