code: public int getHitCount() throws CoreException
  	{
  		synchronized (sessions)
  		{
  			if (sessions.isEmpty())
  			{
  				return -1;
  			}
  			int result = 0;
  			for (Iterator<PerSessionInfo> i = sessions.values().iterator(); i.hasNext();)
  			{
  				PerSessionInfo info = (PerSessionInfo) i.next();
  				if (info.hitCount > 0)
  				{
  					result += info.hitCount;
  				}
  			}
  			return result > 0 ? result : -1;
  		}
  	}
docs: Hit count