Snc\RedisBundle\Session\Storage\Handler\RedisSessionHandler::lockSession PHP Method

    protected function lockSession($sessionId)
    {
        $attempts = 1000000 / $this->spinLockWait * $this->lockMaxWait;
        $this->token = uniqid();
        $this->lockKey = $sessionId . '.lock';
        for ($i = 0; $i < $attempts; ++$i) {
            // We try to aquire the lock
            $setFunction = function ($redis, $key, $token, $ttl) {
                if ($redis instanceof \Redis) {
                    return $redis->set($key, $token, array('NX', 'PX' => $ttl));
                } else {
                    return $redis->set($key, $token, 'PX', $ttl, 'NX');
                }
            };
            $success = $setFunction($this->redis, $this->getRedisKey($this->lockKey), $this->token, $this->lockMaxWait * 1000 + 1);
            if ($success) {
                $this->locked = true;
                return true;
            }
            usleep($this->spinLockWait);
        }
        return false;
    }