System.Threading.SpinLock.Enter C# (CSharp) Method

        public void Enter(ref bool lockTaken)
        {
            if (lockTaken)
                throw new ArgumentException ("lockTaken", "lockTaken must be initialized to false");
            if (isThreadOwnerTrackingEnabled && IsHeldByCurrentThread)
                throw new LockRecursionException ();

            int slot = -1;

            RuntimeHelpers.PrepareConstrainedRegions ();
            try {
                slot = Interlocked.Increment (ref ticket.Users) - 1;

                SpinWait wait = new SpinWait ();
                while (slot != ticket.Value) {
                    wait.SpinOnce ();

                    while (stallTickets != null && stallTickets.TryRemove (ticket.Value))
                        ++ticket.Value;
                }
            } finally {
                if (slot == ticket.Value) {
                    lockTaken = true;
                    threadWhoTookLock = Thread.CurrentThread.ManagedThreadId;
                } else if (slot != -1) {
                    // We have been interrupted, initialize stallTickets
                    if (stallTickets == null)
                        Interlocked.CompareExchange (ref stallTickets, new ConcurrentOrderedList<int> (), null);
                    stallTickets.TryAdd (slot);
                }
            }
        }

        private static void Main(string[] args)
        {
            SpinLock slock = new SpinLock(false);
            long sum1 = 0;
            long sum2 = 0;
            Parallel.For(0, 10000, i => { sum1 += i; });

            Parallel.For(0, 10000, i =>
            {
                bool lockTaken = false;
                try
                {
                    slock.Enter(ref lockTaken);
                    sum2 += i;
                }
                finally
                {
                    if (lockTaken)
                        slock.Exit(false);
                }
            });

            Console.WriteLine("Num1的值为:{0}", sum1);
            Console.WriteLine("Num2的值为:{0}", sum2);
        }