Cross-reference problem

[finnam]

Hi guys!

We've met a problem with JBoss cache and we don't know if it's a bug or usage problem.
We have an annotated User class wich has an ArrayList buddies property. We put two instances of User class to the cache and each instance has a reference to another one from the buddies list. The code is like this:

User user1 = new User();
User user2 = new User();
cache.putObject(user1.getFqn(), user1);
cache.putObject(user2.getFqn(), user2);
//skipped
user1.getBuddies().add(user2);
//skipped
user2.getBuddies().add(user1);

On some event we are removing user1 from the cache:

user2.getBuddies().remove(user1);
cache.removeObject(user1.getFqn());

And then we are putting it again:

cache.putObject(user1.getFqn(), user1);
user2.getBuddies().add(user1);

This last line of code throws IllegalStateException with the following message:
AopInstance.incrementRefCount: source fgn /users/user1 is already present.

After a small debugging we added following befor removing user1 from cache:

user1.getBuddies().clean();

And all the problems are gone.

So, should we really remove all the references to the cached objects from user1 before removing it from the cache or it's a problem of illegal usage?

[ben.wang]

You should not. On the surface, it looks simple corss referencing to me. Which version of JBossCache you use?

[finnam]

You should not. On the surface, it looks simple corss referencing to me. Which version of JBossCache you use?

Hi Ben!

We are using JBossCache 1.4.0.SP1.

Any ideas?

Thanks in advance,
Alex.

[ben.wang]

Alex, is it possible that you can put together a simple unit test case so I can try it out on my end then?

-Ben