Fixed concurrency problem.

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@9070 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/openfire/spi/PresenceManagerImpl.java

@@ -32,6 +32,7 @@ import org.jivesoftware.openfire.user.UserNotFoundException;
 import org.jivesoftware.util.LocaleUtils;
 import org.jivesoftware.util.Log;
 import org.jivesoftware.util.StringUtils;
+import org.jivesoftware.util.lock.LockManager;
 import org.jivesoftware.util.cache.Cache;
 import org.jivesoftware.util.cache.CacheFactory;
 import org.xmpp.packet.JID;
@@ -44,6 +45,7 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.concurrent.locks.Lock;
 
 /**
  * Simple in memory implementation of the PresenceManager interface.
@@ -501,7 +503,10 @@ public class PresenceManagerImpl extends BasicModule implements PresenceManager
         Connection con = null;
         PreparedStatement pstmt = null;
         ResultSet rs = null;
+        Lock lock = LockManager.getLock(username + "pr");
         try {
+            lock.lock();
+            if (!offlinePresenceCache.containsKey(username) || !lastActivityCache.containsKey(username)) {
                 con = DbConnectionManager.getConnection();
                 pstmt = con.prepareStatement(LOAD_OFFLINE_PRESENCE);
                 pstmt.setString(1, username);
@@ -520,11 +525,13 @@ public class PresenceManagerImpl extends BasicModule implements PresenceManager
                     lastActivityCache.put(username, NULL_LONG);
                 }
             }
+        }
         catch (SQLException sqle) {
             Log.error(sqle);
         }
         finally {
             DbConnectionManager.closeConnection(rs, pstmt, con);
+            lock.unlock();
         }
     }
 }
\ No newline at end of file