AsyncLocal<T>与ThreadLocal<T>区别研究

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace ATLearn
{
    /// <summary>
    /// Guid工厂
    /// </summary>
    static class GuidFactory
    {
        private static ThreadLocal<string> _localGuid = new ThreadLocal<string>();
        //private static AsyncLocal<string> _localGuid = new AsyncLocal<string>();
        public static string CurrentGuid
        {
            get
            {
                if (_localGuid.Value == null)
                {
                    _localGuid.Value = Guid.NewGuid().ToString();
                }
                return _localGuid.Value;
            }
        }
    }

    class APP
    {
        private Task<int> awaitFunction()
        {
            return Task.Run<int>(() =>
            {
                Console.WriteLine("awaitFunction：" + GuidFactory.CurrentGuid);
                return ;
            });
        } 

        private async void asyncFunction()
        {
            Console.WriteLine("asyncFunction：" + GuidFactory.CurrentGuid);
            int num = await awaitFunction();
            Console.WriteLine("asyncFunction：" + GuidFactory.CurrentGuid);
        }

        public APP()
        {
            asyncFunction();
            asyncFunction();

            while (true)
            {
                Thread.Sleep();
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            APP App = new APP();
        }
    }
}

    /// <summary>
    /// Guid工厂
    /// </summary>
    static class GuidFactory
    {
        //private static ThreadLocal<string> _localGuid = new ThreadLocal<string>();
        private static AsyncLocal<string> _localGuid = new AsyncLocal<string>();
        public static string CurrentGuid
        {
            get
            {
                if (_localGuid.Value == null)
                {
                    _localGuid.Value = Guid.NewGuid().ToString();
                }
                return _localGuid.Value;
            }
        }
    }