Is this a LockMode bug or a feature?

tetrione · **Posted:** Fri Jul 30, 2004 10:25 am

Below is the test case that demonstrates odd behavior. Parent and Child are nothing special just regular parent (one-to-many) child relation and both are versioned. Both 2.1.4 and 2.1.3 exhibit the same behavior.

Code:

    public void testLockModeBug () throws Exception {

        Session s = HibernateSessionFactoryHolder.getSessionFactory ().openSession ();
        
        // create parent and children
        Parent p = new Parent ();
        p.setName ("test parent");
        Set children = new HashSet (); 
        for (int i = 0; i < 2; i++) {
           Child c = new Child (); c.setName ("child " + String.valueOf (i+1)); c.setParent (p);
           children.add (c);
        }
        p.setChildren (children);
        
        s.saveOrUpdate (p);
        s.flush ();
        s.close ();
        
        // update children collection in one session and try to lock parent in another 
        Session s0 = HibernateSessionFactoryHolder.getSessionFactory ().openSession ();
        Session s1 = HibernateSessionFactoryHolder.getSessionFactory ().openSession ();
        
        try {
            // retrieve the created parent
            Parent p0 = (Parent) s0.load (Parent.class, p.getId ());
            for (Iterator iter = p0.getChildren ().iterator (); iter.hasNext ();) {
                Child element = (Child) iter.next ();
                element.setName ("Updated name");
                break;
            }
            s0.flush ();
            s0.close ();
        
            try {
                s1.lock (p, LockMode.READ);
            } catch (StaleObjectStateException sose) {
                // this is correct
            }
        
            try {
                s1.lock (p, LockMode.READ);
                fail ("Object has to be stale still");
            } catch (StaleObjectStateException sose) {
                // this is correct
            }
        } finally  {
            try { s1.close (); } catch (Throwable t) {}
        }
        
    }

christian · **Posted:** Fri Jul 30, 2004 10:26 am

You should read about transactions, there isn't any in your code, just random data access.

tetrione · **Posted:** Fri Jul 30, 2004 10:52 am

I did read about transactions, but what does it have to do with transactions?

In any case, I just dropped transactional code since it is noisy and not related to what I thought (and still think) is a bug.

Another reason I think it is a bug is the following test that passes:

Code:

    public void testLockModeNonBug () throws Exception {

        Session s = HibernateSessionFactoryHolder.getSessionFactory ().openSession ();
        
        // create parent and children
        Parent p = new Parent ();
        p.setName ("test parent");
        s.saveOrUpdate (p);
        s.flush ();
        s.close ();
        
        // update children collection in one session and try to lock parent in another 
        Session s0 = HibernateSessionFactoryHolder.getSessionFactory ().openSession ();
        try {
            // retrieve the created parent
            Parent p0 = (Parent) s0.load (Parent.class, p.getId ());
            p0.setName ("name update");
            s0.flush ();
        } finally {
            try { s0.close (); } catch (Throwable t) {}
        }
        
        Session s1 = HibernateSessionFactoryHolder.getSessionFactory ().openSession ();
        try {
            try {
                s1.lock (p, LockMode.READ);
                fail ("Object has to be stale still");
            } catch (StaleObjectStateException sose) {
                // this is correct
            }
        
            try {
                s1.lock (p, LockMode.READ);
                fail ("Object has to be stale still");
            } catch (StaleObjectStateException sose) {
                // this is correct
            }
        } finally  {
            try { s1.close (); } catch (Throwable t) {}
        }
        
    }

christian · **Posted:** Fri Jul 30, 2004 11:18 am

As long as I see close() in your code without transaction commit or rollback, I will not read on.

tetrione · **Posted:** Fri Jul 30, 2004 11:36 am

oh well ...

Code:

    public void testLockModeBug () throws Exception {

        Session s = HibernateSessionFactoryHolder.getSessionFactory ().openSession ();
        
        Parent p = new Parent ();
        p.setName ("test parent");
        Set children = new HashSet (); 
        for (int i = 0; i < 2; i++) {
           Child c = new Child (); c.setName ("child " + String.valueOf (i+1)); c.setParent (p);
           children.add (c);
        }
        p.setChildren (children);
        
        s.saveOrUpdate (p);
        s.flush ();
        s.close ();
        
        Session s0 = HibernateSessionFactoryHolder.getSessionFactory ().openSession ();
        try {
            Parent p0 = (Parent) s0.load (Parent.class, p.getId ());
            for (Iterator iter = p0.getChildren ().iterator (); iter.hasNext ();) {
                Child element = (Child) iter.next ();
                element.setName ("Updated name");
                break;
            }
            s0.flush ();
        } finally {
            s0.close ();
        }

        Session s1 = HibernateSessionFactoryHolder.getSessionFactory ().openSession ();
        Transaction t0 = s1.beginTransaction ();
        boolean bShallCommit = true;
        try {
            try {
                s1.lock (p, LockMode.READ);
            } catch (StaleObjectStateException sose) {
                bShallCommit = false;
                t0.rollback ();
            }
        } finally  {
            if (bShallCommit) { t0.commit (); }
        }

        Transaction t1 = s1.beginTransaction ();
        bShallCommit = true;
        try{
            try {
                s1.lock (p, LockMode.READ);
                fail ("Object has to be stale still");
            } catch (StaleObjectStateException sose) {
                bShallCommit = false;
                try { t1.rollback (); } catch (Throwable t) { t.printStackTrace (); }
            }
        } finally  {
            if (bShallCommit) {
                try { t1.commit (); } catch (Throwable t) { t.printStackTrace (); }
            }
            try { s1.close (); } catch (Throwable t) { t.printStackTrace (); }
        }
        
    }

by the way I had no doubt that you did not read the code in the first place. No way in hell you could answer it that fast ...

christian · **Posted:** Fri Jul 30, 2004 11:38 am

And again, I stopped here:

[code]

tetrione · **Posted:** Fri Jul 30, 2004 11:39 am

you know what whatever ...