gistfile1.txt

    public class SyncDictionary : Dictionary<object, object>
    {
        private volatile int version;
        private volatile bool isWriterInProgress;
        public new object this[object key]
        {
            get
            {
                object value;
                int currentversion;
                int spinCount = 0;
                do
                {
                    currentversion = version;
                    TryGetValue(key, out value);
                    if ((++spinCount) % 8 == 0)
                    {
                        Thread.Sleep(1);
                    }
                } while (isWriterInProgress || (currentversion != version));

                return value;
            }
            set
            {
                isWriterInProgress = true;
                base[key] = value;
                Interlocked.Increment(ref version);
                isWriterInProgress = false;
            }
        }
    }