System.Threading.ClientInterlocked.Add C# (CSharp) Method

        public static int Add(ref int location, int value)
        {
            return Interlocked.Add(ref location, value);
        }

        public void EnterReadLock()
        {
            ClientSpinWait sw = new ClientSpinWait();

            do
            {
                while ((rwlock & (RwWrite | RwWait)) > 0)
                {
                    sw.SpinOnce();
                }

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

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