final Thread registerAdId = new Thread(new Runnable() {
    @Override
    public void run() {
        try {
            adId = AdvertisingIdClient.getAdvertisingIdInfo(currentContext);
        } catch (Exception e) {
            // Logging
        }
    }
});

registerAdId.start();
    try {
       registerAdId.join();
    } catch (InterruptedException e) {
       // Logging
    }
    return adId;