線程c＃中的CPU使用率高

Question

嗨，我在運行此線程時的CPU使用率很高（15-16％），除非“ ssStop”設置為true（有效），否則該線程應該一直循環運行，但是在運行時我打開了該線程任務管理器，我看到該程序正在消耗15％的計算機處理能力，一旦退出線程，它就會下降到1-2％。 即使在使用EventWaitHandle時（我發現它在網上搜索此問題）仍然保持很高的水平，有人知道我在做什么錯嗎？：

public void Receive()
{
    try
    {              
        bool firstTimeRun = true;
        TcpListener ssTcpListener = new TcpListener(IPAddress.Any, 1500);
        TcpClient tcpReceiver;
        ssTcpListener.Start();
        while (!ssStop)
        {
            //Start listening for connection.
            //Accept any incoming connection requests on port 1500.
            tcpReceiver = new TcpClient();
            if (ssTcpListener.Pending())
            {
                tcpReceiver = ssTcpListener.AcceptTcpClient();
            }
            if (tcpReceiver.Connected)
            {
                //looped for first time; receives whole image.
                if (firstTimeRun)
                {
                    //TCP connected. Receive images from contact
                    NetworkStream receivedNs = new NetworkStream(tcpReceiver.Client);
                    Bitmap image = new Bitmap(receivedNs);
                    receivedImage = image;
                    pboScrnShare.Image = image;
                    receivedNs.Flush();
                    firstTimeRun = false;                            
                }
                //second time or higher looped; receives difference and overlays it.
                else if (!firstTimeRun)
                {
                    NetworkStream receivedNs = new NetworkStream(tcpReceiver.Client);

                    //Put image into picturebox.
                    receivedImage2 = new Bitmap(receivedNs);
                    receivedImage2.MakeTransparent(Color.Black);
                    Bitmap overlayedImage = new Bitmap(receivedImage.Width, receivedImage.Height);

                    using (Graphics gr = Graphics.FromImage(overlayedImage))
                    {
                        gr.DrawImage(receivedImage, new Point(0, 0));
                        gr.DrawImage(receivedImage2, new Point(0, 0));
                    }


                    try
                    {
                        pboScrnShare.Image = overlayedImage;
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.Message, "pbo second run");
                    }
                    receivedImage2.Dispose();
                    if (this.InvokeRequired) { this.Invoke(new MethodInvoker(delegate() { receivedImage = overlayedImage; })); } else { receivedImage = overlayedImage; }
                    receivedNs.Flush();
                }
                tcpReceiver.Close();
            }
            myEventWaitHandle.WaitOne(10, true);
        }
        ssTcpListener.Stop();
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString(), "Invited ReceiveSS()", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
}

Answer 1

您正在刻錄CPU周期，忙於輪詢連接。 考慮到Pending返回false的大部分時間，您的循環像這樣旋轉：

while (!ssStop)
{
    tcpReceiver = new TcpClient();
    myEventHandle.WaitOne(10, false);
}

現在，如果未設置myEventHandle，則WaitOne的10ms延遲將有效地限制執行，但我的猜測是該事件已設置，以便WaitOne立即返回true 。

不需要輪詢連接，因為AcceptTcpClient將阻止等待連接。 因此，如果您稍微更改了代碼，它應該可以按預期工作：

while (!ssStop)
{
    TcpClient tcpReceiver = ssTcpListener.AcceptTcpClient(); // this blocks
    ...
}