code: private FileDetails getOldestInactive() {
  		for (FileDetails curFd : fileList) {
  			if (curFd.pid == null)
  				return curFd ;
  			synchronized(activeFilesMap) {
  				FileDetails cur4Pid = activeFilesMap.get(curFd.pid) ;
  				if ( cur4Pid == null || cur4Pid != curFd) {
  					return curFd ;
  				}
  			}
  		}
  		return null ;
  	}
docs: get oldest file in cache that is not currently in use by a pid (ie: current log/trace/textLog for some process)
  This method assumes that fileList is already sync'd
  @return a FileDetails object representing the oldest inactive file in repository (prime candidate for removal)