c++ - Windows 中的套接字编程发送数据会卡住一段时间并延迟一段时间？

Question

我能够通过套接字编程使用静态类成功发送数据，它适用于少量数据，但在生产环境中它会卡住一段时间，然后又开始发送数据，我无法弄清楚问题是什么？你能帮忙吗代码如下。

            DWORD BytesCount;  
    WSABUF Buffer[1];
    DWORD Flag = 0;

    Buffer[0].len = SendLength;
    Buffer[0].buf = SendData;
    if (WSASend(*socket, Buffer, 1, &BytesCount, Flag, NULL, NULL) != SOCKET_ERROR)
    {
        if (BytesCount != SendLength )
            Result = -2;
        else
        {
            if (ReturnAnswer)
            {
                int Res = 0, recBufStart;
                DWORD RecvCount = 0, AllRecv = 0;

                Buffer[0].len = ReceiveLength;
                Buffer[0].buf = ReceiveData;
                recBufStart = 0;
                saAction = saReceive;

                // We need to Receive until we get all the data. When WSARecv call might only return zero bytes
                bool Stop = true; // true as we dont need to recieve anything from the server.
                while (!Stop)
                {
                    Res = WSARecv(*socket, &Buffer[recBufStart], (recBufStart == 0 ? 1 : 0), &RecvCount, &Flag, NULL, NULL);
                    if (Res == SOCKET_ERROR)
                        Stop = true;
                    else
                    {
                        AllRecv = AllRecv + RecvCount;
                        if (AllRecv == ReceiveLength || RecvCount == 0)
                            Stop = true;    // Stop
                        else
                        {
                            Buffer[0].buf = &ReceiveData[AllRecv];
                            Buffer[0].len = ReceiveLength - (AllRecv);
                            recBufStart = 0;
                        }
                    }
                }

                if (Res == SOCKET_ERROR)
                    Result = WSAGetLastError();                 
            }
        }
    }
    else
        Result = WSAGetLastError();     

Answer 1

我不确定这是否可能是问题所在，但从 WSASend 的 Microsoft 文档中可以看出以下内容:

When issuing a blocking Winsock call such as WSASend with the lpOverlapped parameter set to NULL, Winsock may need to wait for a network event before the call can complete.

此外，您的接收代码似乎相当复杂。在什么情况下 recBufStart 不是 0？我也不会使用变量“停止”。只需发出 break 语句即可退出 while 循环。

编辑:更仔细地查看您的接收代码，您在 while (!Stop) 之前将 Stop 设置为 true，即 while (Stop == false)。所以它不会到达 WSARecv。这是故意的吗？如果是，Microsoft 的解释和我下面的答案似乎表明您的问题，即您不断发送，Winsock 必须等待才能发送更多数据。