在.Net native中的线程池上运行异步任务的性能很差

我发现托管vs .Net本机代码有一个奇怪的区别.我有一个繁重的工作重定向到线程池.当在托管代码中运行应用程序时,一切都运行顺畅,但是一旦我打开本机编译 - 任务运行速度慢几十倍,以至于它挂起UI线程(我猜CPU是如此过载).

以下是调试输出的两个屏幕截图,左侧的屏幕截图来自托管代码,右侧的屏幕截图来自本机编译.正如您所看到的,UI任务所消耗的时间在两种情况下几乎相同,直到启动线程池作业时 - 然后在托管版本中UI经过的时间增长(实际上UI被阻止,您无法采取任何操作).线程池工作的时间不言自明.

重现问题的示例代码:

private int max = 2000;
private async void UIJob_Click(object sender, RoutedEventArgs e)
{
    IProgress progress = new Progress((p) => { MyProgressBar.Value = (double)p / max; });
    await Task.Run(async () => { await SomeUIJob(progress); });
}

private async Task SomeUIJob(IProgress progress)
{
    Stopwatch watch = new Stopwatch();
    watch.Start();
    for (int i = 0; i < max; i++)
    {
        if (i % 100 == 0) { Debug.WriteLine($"     UI time elapsed => {watch.ElapsedMilliseconds}"); watch.Restart(); }
        await Task.Delay(1);
        progress.Report(i);
    }
}

private async void ThreadpoolJob_Click(object sender, RoutedEventArgs e)
{
    Debug.WriteLine("Firing on Threadpool");
    await Task.Run(() =>
   {
       double a = 0.314;
       Stopwatch watch = new Stopwatch();
       watch.Start();
       for (int i = 0; i < 50000000; i++)
       {
           a = Math.Sqrt(a) + Math.Sqrt(a + 1) + i;
           if (i % 10000000 == 0) { Debug.WriteLine($"Threadpool -> a value = {a} got in {watch.ElapsedMilliseconds} ms"); watch.Restart(); };
       }
   });
    Debug.WriteLine("Finished with Threadpool");
}

    for (long i = 0; i < 5000000000; i++)
           {
               MaybeGCMeHere(); // new callsite
               a = Math.Sqrt(a) + Math.Sqrt(a + 1) + i;
               if (i % 1000000000 == 0) { Debug.WriteLine($"Threadpool -> a value = {a} got in {watch.ElapsedMilliseconds} ms"); watch.Restart(); };
    }

...

    [MethodImpl(MethodImplOptions.NoInlining)] // need this so the callsite isn’t optimized away
    private void MaybeGCMeHere()
    {
    }