c# – 为什么SocketAsyncEventArgs的Completed回调在新创建的线

private static readonly HashSet<int> _capturedThreadIds = new HashSet<int>();

private static void RunClient(Socket socket)
{
    var e = new SocketAsyncEventArgs();
    e.SetBuffer(new byte[10000],10000);
    e.Completed += SocketAsyncEventsArgsCompleted;

    Receive(socket,e);
}

private static void Receive(Socket socket,SocketAsyncEventArgs e)
{
    var isAsynchronous = socket.ReceiveAsync(e);
    if (!isAsynchronous)
        SocketAsyncEventsArgsCompleted(socket,e);
}

private static void SocketAsyncEventsArgsCompleted(object sender,SocketAsyncEventArgs e)
{
    if (e.LastOperation != SocketAsyncOperation.Receive || e.SocketError != SocketError.Success || e.BytesTransferred <= 0)
    {
        Console.WriteLine("Operation: {0},Error: {1},BytesTransferred: {2}",e.LastOperation,e.SocketError,e.BytesTransferred);
        return;
    }

    var thread = Thread.CurrentThread;
    if (_capturedThreadIds.Add(thread.ManagedThreadId))
        Console.WriteLine("New thread,ManagedId: " + thread.ManagedThreadId + ",NativeId: " + GetCurrentThreadId());

    //Console.WriteLine(e.BytesTransferred);

    Receive((Socket)sender,e);
}

应用程序的线程行为非常好奇：

> SocketAsyncEventsArgsCompleted方法经常在新线程中运行.我会预料到,在一段时间后,不会创建新的线程.我会期望线程被重用,因为线程池(或IOCP线程池),因为吞吐量非常稳定.
>线程数保持不变,但是在进程资源管理器中可以看到线程经常被创建和销毁.同样,我也不希望创建或销毁线程.

你可以解释应用行为吗？

编辑：“低”吞吐量是每秒20个消息(大约200 KB / s).如果我将吞吐量提高到每秒超过1000条消息(50 MB / s),则应用程序行为不会改变.