function release()
    {
        $lockRes = static::_getLocksDir("{$this->realm}.lockfile");

        if ( null === $file = $this->file )
            if (false === $file = fopen($lockRes, 'w+') )
                throw new \RuntimeException(sprintf(
                    'Failed To Open Resource (%s).'
                    , $lockRes
                ));


        ## Release Lock Res.
        #
        $this->file = null;

        if (! flock($file, LOCK_UN) )
            throw new \RuntimeException(sprintf(
                'FAILED to release lock[%s] on resource (%s).'
                , $this->realm
                , $lockRes
            ));


        fclose($file);
        unlink($lockRes);

        return true;
    }