轮询算法

       static void Test9()
        {
            var strs = new List<string>
            {
                "192.168.100.125",
                "192.168.100.126",
                "192.168.100.127",
                "192.168.100.128",
                "192.168.100.130",
                "192.168.100.131"
            };

            var addressEntry = new AddressEntry(strs);
            var item = addressEntry.GetAddress();
        }

        protected class AddressEntry
        {
            #region Field

            private int _index;
            private int _lock;
            private readonly int _maxIndex;
            private readonly string[] _address;

            #endregion Field

            #region Constructor

            public AddressEntry(IEnumerable<string> address)
            {
                _address = address.ToArray();
                _maxIndex = _address.Length - 1;
            }

            #endregion Constructor

            #region Public Method

            public string GetAddress()
            {
                while (true)
                {
                    //如果无法得到锁则等待
                    if (Interlocked.Exchange(ref _lock, 1) != 0)
                    {
                        default(SpinWait).SpinOnce();
                        continue;
                    }

                    var address = _address[_index];

                    //设置为下一个
                    if (_maxIndex > _index)
                        _index++;
                    else
                        _index = 0;

                    //释放锁
                    Interlocked.Exchange(ref _lock, 0);

                    return address;
                }
            }

            #endregion Public Method
        }