在下面的代码中，由于接口的原因，类LazyBar必须从它的方法返回一个任务(出于参数的考虑，不能更改)。如果LazyBars的实现是不寻常的，因为它恰好快速和同步地运行——从方法中返回一个No-Operation任务的最佳方法是什么?

我已经使用下面的Task.Delay(0)，但是我想知道如果函数被大量调用(为了论证，说每秒数百次)，这是否有任何性能副作用:

这个语法上的糖会不会变成一个大问题? 它是否开始阻塞应用程序的线程池? 编译器是否足以处理不同的Delay(0) ? 返回Task.Run(() => {});有什么不同吗?

有没有更好的办法?

using System.Threading.Tasks;

namespace MyAsyncTest
{
    internal interface IFooFace
    {
        Task WillBeLongRunningAsyncInTheMajorityOfImplementations();
    }

    /// <summary>
    /// An implementation, that unlike most cases, will not have a long-running
    /// operation in 'WillBeLongRunningAsyncInTheMajorityOfImplementations'
    /// </summary>
    internal class LazyBar : IFooFace
    {
        #region IFooFace Members

        public Task WillBeLongRunningAsyncInTheMajorityOfImplementations()
        {
            // First, do something really quick
            var x = 1;

            // Can't return 'null' here! Does 'Task.Delay(0)' have any performance considerations?
            // Is it a real no-op, or if I call this a lot, will it adversely affect the
            // underlying thread-pool? Better way?
            return Task.Delay(0);

            // Any different?
            // return Task.Run(() => { });

            // If my task returned something, I would do:
            // return Task.FromResult<int>(12345);
        }

        #endregion
    }

    internal class Program
    {
        private static void Main(string[] args)
        {
            Test();
        }

        private static async void Test()
        {
            IFooFace foo = FactoryCreate();
            await foo.WillBeLongRunningAsyncInTheMajorityOfImplementations();
            return;
        }

        private static IFooFace FactoryCreate()
        {
            return new LazyBar();
        }
    }
}