CacheSkipsIfNotFinished.cs

using System;
using System.Collections.Generic;

namespace ConsoleApp2
{
    public class ReloadingCache:IDisposable
    {
        private List<string> _cachedItems;
        private System.Threading.Timer _timer;
        private System.Threading.Mutex _mutex = new System.Threading.Mutex();

        public ReloadingCache()
        {
            _cachedItems = MyMethodThatGivesMeTheList();
            _timer = new System.Threading.Timer(state =>
            {
                if (_mutex.WaitOne(0))
                {
                    try
                    {
                        System.Threading.Interlocked.Exchange(ref _cachedItems, MyMethodThatGivesMeTheList());
                    }
                    finally
                    {
                        _mutex.ReleaseMutex();
                    }
                }
            }, null, 30000, 30000);
        }

        public void Dispose()
        {
            _mutex.Dispose();
            _timer.Dispose();
        }

        public List<string> GetListToDoWork()
        {
            return System.Threading.Volatile.Read(ref _cachedItems);
        }
        
        private List<string> MyMethodThatGivesMeTheList()
        {
            return new List<string>()
            {
                "Test1",
                "Test2"
            };
        }
    }
}