Lock an object that creates ID

Question

Would the following method ensure that only one thread can read an ID at a time? I have a parallel process which uses the following method and I need it to return unique IDs. Unfortunately I cannot change the way the ID is structured.

private static int Seq = 0;
private static long dtDiff = 0;
private static object thisLock = new object();
private static object BuildClientID(string Code)
{
    lock (thisLock)
    {
        object sReturn = "";
        Seq++;
        dtDiff++;                
        if (Seq == 1000)
        {
            Seq = 0;
            dtDiff = DateAndTime.DateDiff(DateInterval.Second, DateTime.Parse("1970-01-01"), DateTime.Now);
         }
         sReturn = dtDiff.ToString() + Code + Seq.ToString("000");
            return sReturn;
    }
}

Answer 1

I don't see any reason it wouldn't. Both the lock object and the method are static. The only thing you need to determine is, do you need a more sophisticated form of locking like a Mutex, SpinLock, ReaderWriterLock, or Semaphore.

You'll need to study those, and here is a good link to get started.

Answer 2

Yes, it will work fine as both threads will use the same static object as the lock object and will have to wait for each other.

edit

Based on Dan's comments: consider making Seq and dtDiff properties and put access to them inside the same lock.