线程c中的CPU使用率高＃

问题描述：

嗨我运行这个线程时CPU占用率很高（15-16％），它是一个线程，应该保持循环，除非“ssStop”设置为true（哪个工作）但是，在运行时，我打开任务管理器，发现程序使用了15％的计算机处理能力，一旦线程退出，它将降低到1-2％。使用的EventWaitHandle，我发现寻找这个问题即使在网上它仍然这么高，没有人知道我在做什么错在这里？：线程c中的CPU使用率高＃

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); 
    } 
}

如果你能负担得起的每个循环中放弃对线程20毫秒或更多，你可以插入一个'睡眠（1）'某处你的循环允许其他线程执行。但是，您的代码还存在其他问题。由于它是工作代码，因此可以考虑将其发布到codereview.stackexchange.com，以便获得一些额外的反馈。即使你使用WaitEventHandle，我认为它不会对你的CPU使用率产生任何影响，除非在其他线程中有某些事情要做。 –

添加一些仪器来测量时钟滴答。这将有助于缩小CPU使用率。测量系统或函数调用两侧的时钟滴答声。但请注意，测量刻度还会带来一些开销，所以不要做生产。测量总是比猜测好.... –

答

您正在燃烧的CPU周期忙轮询的连接。考虑到大部分的时间Pending是返回false，你的循环转圈这样的：

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

现在，如果myEventHandle没有设置那么WaitOne 10ms的延迟将切实油门执行，但我的猜测是，该事件被设置所以WaitOne立即返回true。

由于AcceptTcpClient将阻止等待连接，所以不需要轮询连接。所以，如果你身边有点改变了你的代码，它应该按预期工作：

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

线程c中的CPU使用率高＃

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