Losing session while using redis Driver

Yeah session_write_close() is needed and already implemented. 
However, while the 3.1.6 patch is correctly using the "SET resource-name anystring NX EX max-lock-time" from Redis home page https://redis.io/commands/set I'd say that the code is wrong. It is wrong because from 3.1.6, no retries are being made but instead there is a return FALSE after the failed call to $this->_redis->set() shouldn't that be a continue?

PHP Code:

$attempt = 0;
do
{
    if (($ttl = $this->_redis->ttl($lock_key)) > 0)
    {
        sleep(1);
        continue;
    }

    $result = ($ttl === -2)
        ? $this->_redis->set($lock_key, time(), array('nx', 'ex' => 300))
        : $this->_redis->setex($lock_key, 300, time());

    if ( ! $result)
    {
        log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id);
        return FALSE; // THIS SHOULD BE continue TO ALLOW UP TO 30 ATTEMPTS TO GET THE LOCK?
    }

    $this->_lock_key = $lock_key;
    break;
}
while (++$attempt < 30);