Database Locks not working

Question

Hello!
I am having some problems with the Berkley DB XML Locking System. My database is configured as follows:
     _envConfig = new EnvironmentConfig();
     _envConfig.setRunFatalRecovery(doFatalRecovery);
     _envConfig.setRunRecovery(!doFatalRecovery);
     _envConfig.setVerboseRecovery(true);
     _envConfig.setAllowCreate(true);         
     _envConfig.setCacheCount(1);
     envConfig.setCacheSize(DBCACHE_SIZE * 1024 * 1024);
     _envConfig.setInitializeCache(true);            
     _envConfig.setTransactional(true); 
     envConfig.setMaxLocks(MAXLOCKS);
     envConfig.setMaxLockers(MAXLOCKERS);
     envConfig.setMaxLockObjects(MAXLOCKOBJECTS);
     // enable locking
     _envConfig.setInitializeLocking(true);
     _envConfig.setLockTimeout(50000000);
     logInfo("Database locking enabled.");
     // Configure db to perform deadlock detection internally, and to
// choose the transaction that has performed the least amount
// of writing to break the deadlock in the event that one
// is detected.
_envConfig.setLockDetectMode(LockDetectMode.MINWRITE);
Then I try to modify one object in my first thread:
xmlTransaction = xmlManager.createTransaction();               
               xmlContainer = xmlManager.openContainer( xmlTransaction, _collection);
               context = xmlManager.createQueryContext(XmlQueryContext.LiveValues, XmlQueryContext.Eager);               
               // Declare the read/modify/write cycle
          XmlDocumentConfig docConfig = new XmlDocumentConfig();
          docConfig.setLockMode(com.sleepycat.db.LockMode.RMW);
               XmlQueryExpression xmlQueryExprDocs = _xmlManager.prepare( xmlTransaction, sQuery, xmlQueryContext);
     results = xmlQueryExprDocs.execute( xmlTransaction, _context, docConfig);            
     xmlQueryExprDocs.delete();     
     // document(s) found - create modify, update objects
     * Iterate over _result documents
     while (_results.hasNext()) {
                    modify = xmlManager.createModify();
                    updateContext = xmlManager.createUpdateContext();               
          docValue = _results.next();                  
          xmlDoc = docValue.asDocument();
          numMod = modify.execute(xmlTransaction, docValue, context, updateContext);                    
In my second thread I try to read the same object:
xmlTransaction = _xmlManager.createTransaction(null, cfg);     
XmlContainer xmlContainer = getXmlManager().openContainer(xmlTransaction, sContainer, contConfig);
context = _xmlManager.createQueryContext(XmlQueryContext.DeadValues, XmlQueryContext.Eager);             
xmlQueryExpr = _xmlManager.prepare( xmlTransaction, sQuery, xmlQueryContext);
     results = xmlQueryExpr.execute( context);
And then instead of waiting on the first object to unlock the database just logs:
Transaction that opened the DB handle is still active
I just want the db to wait until the modify is ready and then do the query in the second thread.
What am I doing wrong?
Thanks for your help!
Edited by: user11285545 on 19.06.2009 04:18

Answer 1

Hello,
I think you want to post this to the [Db XML forum|http://forums.oracle.com/forums/forum.jspa?forumID=274] instead of the BDB JE forum.
Charles Lamb