static function init( $time=null )
    {
        if (self::$start == null || $time != null)
        {
            if ($time == null)
            {
                $time = microtime(true);
            }
            self::$start = $time;
        }
        if (self::$hostname == null)
        {
            self::$hostname = gethostname();
        }
        if (self::$script_name == null && isset($_SERVER['SCRIPT_NAME']))
        {
            self::$script_name = $_SERVER['SCRIPT_NAME'];
        }
        if (self::$server_name == null && isset($_SERVER['SERVER_NAME']))
        {
            self::$server_name = $_SERVER['SERVER_NAME'];
        }
        if ( !self::$shutdown_registered )
        {
            self::$shutdown_registered = true;
            register_shutdown_function('pinba::flush');
        }

    }