我在找一个简单的实现并行（多线程）排序算法在C＃中，可以在名单，其中经营的; T＆GT; 或阵列，并有可能使用并行扩展但该部分不是严格必需的。

I'm looking for a simple implementation of a parallelized (multi-threaded) sort algorithm in C# that can operate on List<T> or Arrays, and possibly using Parallel Extensions but that part isn't strictly necessary.

编辑：弗兰克·克鲁格提供了一个很好的答案，但是我想这个例子转换为一个不使用LINQ。还要注意的是 Parallel.Do（）似乎已经被取代由 Parallel.Invoke（）。

Frank Krueger provides a good answer, however I wish to convert that example to one that doesn't use LINQ. Also note that Parallel.Do() seems to have been superceded by Parallel.Invoke().

感谢。

推荐答案

摘自阴暗面，在他的文章Parallel扩展.NET框架我们有这个并行扩展版本的快速排序的：

From "The Darkside" in his article Parallel Extensions to the .Net Framework we have this parallel extensions version of quicksort:

private void QuicksortSequential<T>(T[] arr, int left, int right) 
where T : IComparable<T>
{
    if (right > left)
    {
        int pivot = Partition(arr, left, right);
        QuicksortSequential(arr, left, pivot - 1);
        QuicksortSequential(arr, pivot + 1, right);
    }
}

private void QuicksortParallelOptimised<T>(T[] arr, int left, int right) 
where T : IComparable<T>
{
    const int SEQUENTIAL_THRESHOLD = 2048;
    if (right > left)
    {
        if (right - left < SEQUENTIAL_THRESHOLD)
        {

            QuicksortSequential(arr, left, right);
        }
        else
        {
            int pivot = Partition(arr, left, right);
            Parallel.Do(
                () => QuicksortParallelOptimised(arr, left, pivot - 1),
                () => QuicksortParallelOptimised(arr, pivot + 1, right));
        }
    }
}

注意，他恢复到一个顺序排序一旦项目数小于2048

Notice that he reverts to a sequential sort once the number of items is less than 2048.