HttpWebRequest ReadWriteTimeout 在 .NET 中被忽略；在单声道工作

Question

将数据写入 Web 服务器时，我的测试显示 HttpWebRequest.ReadWriteTimeout 被忽略，与 MSDN spec 相反.例如，如果我将 ReadWriteTimeout 设置为 1(=1 毫秒)，调用 myRequestStream.Write() 传递一个需要 10 秒传输的缓冲区，它传输成功并且永远不会使用 .NET 3.5 SP1 超时。在 Mono 2.6 上运行的相同测试如预期的那样立即超时。有什么问题吗？

Answer 1

似乎存在一个错误，当在 BeginGetRequestStream() 返回给您的 Stream 实例上设置写入超时时，它不会向下传播到 native 套接字。我将提交错误以确保此问题在 .NET Framework 的 future 版本中得到纠正。

这是一个解决方法。

private static void SetRequestStreamWriteTimeout(Stream requestStream, int timeout)
{
  // Work around a framework bug where the request stream write timeout doesn't make it
  // to the socket. The "m_Chunked" field indicates we are performing chunked reads. Since
  // this stream is being used for writes, the value of this field is irrelevant except
  // that setting it to true causes the Eof property on the ConnectStream object to evaluate
  // to false. The code responsible for setting the socket option short-circuits when it
  // sees Eof is true, and does not set the flag. If Eof is false, the write timeout
  // propagates to the native socket correctly.

  if (!s_requestStreamWriteTimeoutWorkaroundFailed)
  {
    try
    {
      Type connectStreamType = requestStream.GetType();
      FieldInfo fieldInfo = connectStreamType.GetField("m_Chunked", BindingFlags.NonPublic | BindingFlags.Instance);
      fieldInfo.SetValue(requestStream, true);
    }
    catch (Exception)
    {
      s_requestStreamWriteTimeoutWorkaroundFailed = true;
    }
  }

  requestStream.WriteTimeout = timeout;
}

private static bool s_requestStreamWriteTimeoutWorkaroundFailed;