[prev in list] [next in list] [prev in thread] [next in thread] 

List:       xmlbeans-dev
Subject:    [jira] Resolved: (XMLBEANS-300) Threading issue leads to NPE in
From:       "Radu Preotiuc-Pietro (JIRA)" <xmlbeans-dev () xml ! apache ! org>
Date:       2007-04-27 0:22:17
Message-ID: 31085044.1177633337375.JavaMail.jira () brutus
[Download RAW message or body]


     [ https://issues.apache.org/jira/browse/XMLBEANS-300?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel \
]

Radu Preotiuc-Pietro resolved XMLBEANS-300.
-------------------------------------------

       Resolution: Fixed
    Fix Version/s:  Version 2.3

Fixed with svn revision 529824.


> Threading issue leads to NPE in SchemaComponent$Ref.getComponent
> ----------------------------------------------------------------
> 
> Key: XMLBEANS-300
> URL: https://issues.apache.org/jira/browse/XMLBEANS-300
> Project: XMLBeans
> Issue Type: Bug
> Components: XmlObject
> Affects Versions: Version 2, Version 2.1, Version 2.2
> Reporter: Gordon Eastman
> Fix For:  Version 2.3
> 
> Attachments: XMLBEANS-300.patch.txt
> 
> 
> We have seen this NPE during normal use of our application on a MP Solaris system \
> using XmlBeans 2.0.0. I tested and confirmed it is still a problem in 2.2.0: \
> java.lang.NullPointerException at \
> org.apache.xmlbeans.SchemaComponent$Ref.getComponent(SchemaComponent.java:104) at \
> org.apache.xmlbeans.SchemaType$Ref.get(SchemaType.java:872) at \
> org.apache.xmlbeans.impl.schema.SchemaPropertyImpl.getType(SchemaPropertyImpl.java:92)
>  at org.apache.xmlbeans.impl.schema.SchemaTypeImpl.createElementType(SchemaTypeImpl.java:965)
>  at org.apache.xmlbeans.impl.values.XmlObjectBase.create_element_user(XmlObjectBase.java:895)
>  at org.apache.xmlbeans.impl.store.Xobj.getUser(Xobj.java:1592)
> at org.apache.xmlbeans.impl.store.Cur.getUser(Cur.java:2627)
> at org.apache.xmlbeans.impl.store.Cur.getObject(Cur.java:2620)
> at org.apache.xmlbeans.impl.store.Cursor._getObject(Cursor.java:983)
> at org.apache.xmlbeans.impl.store.Cursor.getObject(Cursor.java:2896)
> Here is how to reproduce with the debugger:
> - start two threads, each of which loads a different xml document with the same \
>                 schema type
> - each thread will traverse its document, calling getObject at each element
> - break before traversal starts
> - insert breakpoint at SchemaComponent.java:104, and let both threads run to this \
>                 point
> - resume one thread, and then the other
> - the second thread fails with the NPE
> Here is the code fragment from  SchemaComponent $Ref:
> public final SchemaComponent getComponent()
> {
> if (_schemaComponent == null && _handle != null)
> {
> _schemaComponent = _schemaTypeSystem.resolveHandle(_handle); // this is line 104
> _schemaTypeSystem = null;
> }
> return _schemaComponent;
> }
> Both  threads use the same Ref object, and there is no protection between use of \
> _schemaTypeSystem on line 104 and setting it null on the next line I do not know \
> enough about how thread protection of schema types is designed to know if a \
> localized fix to synchronize the lazy instantiation is appropriate, or if \
> synchronization at a higher level is appropriate.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@xmlbeans.apache.org
For additional commands, e-mail: dev-help@xmlbeans.apache.org


[prev in list] [next in list] [prev in thread] [next in thread]