JAVA-236: make it possible to clean up ThreadLocal

Author: agirbal

src/main/com/mongodb/DBTCPConnector.java

@@ -455,11 +455,18 @@ public String debugString(){
 
     public void close(){
         _closed = true;
-        if ( _portHolder != null )
+        if ( _portHolder != null ) {
             _portHolder.close();
-        if ( _rsStatus != null )
+            _portHolder = null;
+        }
+        if ( _rsStatus != null ) {
             _rsStatus.close();
-        _myPort = null;
+            _rsStatus = null;
+        }
+
+        // below this will remove the myport for this thread only
+        // client using thread pool in web framework may need to call close() from all threads
+        _myPort.remove();
     }
 
     /**
@@ -500,7 +507,7 @@ public int getMaxBsonObjectSize() {
     private DBPortPool _masterPortPool;
     private DBPortPool.Holder _portHolder;
     private final List<ServerAddress> _allHosts;
-    private final ReplicaSetStatus _rsStatus;
+    private ReplicaSetStatus _rsStatus;
     private boolean _closed = false;
     private int maxBsonObjectSize = 0;