BLOCKED threads stop processing messages for producers and consumers in JBM

Issue

• We could see the following threads getting BLOCKED when the network cable is unplugged between two servers running in the cluster:

"RMI TCP Connection(960)-ip" daemon prio=10 tid=0x09914400 nid=0x5c49 waiting for monitor entry [0x3cb23000]
   java.lang.Thread.State: BLOCKED (on object monitor)
    at org.jboss.messaging.core.impl.ChannelSupport.getMessageCount(ChannelSupport.java:491)
    - waiting to lock <0x90665618> (a java.lang.Object)
    at org.jboss.messaging.core.impl.PagingChannelSupport.getMessageCount(PagingChannelSupport.java:148)
    at org.jboss.jms.server.destination.ManagedTopic.getMessageCount(ManagedTopic.java:299)
    at org.jboss.jms.server.destination.ManagedTopic.getDurableMessageCount(ManagedTopic.java:82)
    at org.jboss.jms.server.destination.TopicService.getDurableMessageCount(TopicService.java:244)

and

"Subcriber" daemon prio=10 tid=0x0a54e000 nid=0x12ae waiting for monitor entry [0x623fe000]
   java.lang.Thread.State: BLOCKED (on object monitor)
    at org.jboss.messaging.core.impl.ChannelSupport.getMessageCount(ChannelSupport.java:491)
    - waiting to lock <0x90665618> (a java.lang.Object)
    at org.jboss.messaging.core.impl.PagingChannelSupport.getMessageCount(PagingChannelSupport.java:148)
    at org.jboss.jms.server.destination.ManagedTopic.listSubscriptions(ManagedTopic.java:274)
    at org.jboss.jms.server.destination.ManagedTopic.listDurableSubscriptions(ManagedTopic.java:114)
    at org.jboss.jms.server.destination.TopicService.listDurableSubscriptions(TopicService.java:381)

• The issue does not recover even after the network cable are plugged back.