[jboss-dev-forums] [Design of JCA on JBoss] - Re: JBAS-1808 - MCF MBeans

[adrian@jboss.org]

Vicky, for such trivial changes in general you should just do it.
Silence means approval. :-)

However in this case, you've got a thread safety issue.

If the cels really are an ArrayList then not accessing it in a synchronized block
will produce a ConcurrentModificationException when the pool changes.

Exposing an AarrayList isn't very good api anyway.

The method in InternalManagedConnectionPool should look something like this:


  | // The method should be package protected and just specify a Set
  | Set<ConnectionListener> getConnectionListeners()
  | {
  |    // Avoid concurrency issues with the rest of the pool
  |    synchronized (cls)
  |    {
  |       // "Clone" the internal collections inside the synchronized block to avoid concurrency issues
  |       Set<ConnectionListener result = new HashSet<ConnectionListener>();
  |       result.addAll(cls); // The connections in the pool
  |       result.addAll(checkedOut); // The connections being used by applications
  |       return result;
  |    }
  | }
  | 

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