System.Threading.ServerSimpleRwLock.EnterReadLock C# (CSharp) Method

        public void EnterReadLock()
        {
            ServerSpinWait sw = new ServerSpinWait();
              do {
            while ((rwlock & (RwWrite | RwWait)) > 0)
              sw.SpinOnce();

            if ((Interlocked.Add(ref rwlock, RwRead) & (RwWait | RwWait)) == 0)
              return;

            Interlocked.Add(ref rwlock, -RwRead);
              } while (true);
        }