仅发布版本中的C＃应用​​程序问题

Question

the problem only appears when making Release build and running exe file ( not from visual studio ) in all other combination either it's running from visual studio or running exe everything works fine

I'm running Function Load using backgroundWorker

Load:

while (!Request.GAMELIST.XMLReceived) ;

GameEngine.ParseGameList( Request.GAMELIST.XML );

Request.GAMELIST.XMLReceived = false;

while loop in this fragment works like delay it should wait till XML is received from server and then continue but it stucks in above specified situation

if I'll put MessageBox.show("here we go"); after while loop messageBox will not appear but if I'll put MessageBox.show("here we go"); before while loop application will receive data until I click messagebox ok and then everything will work fine

here is GAMELIST class implementation

public class RequestGAMELIST
{
    public string XML;

    public bool XMLReceived = false;

    public void ParseRequest( string request )
    {
        int index = request.IndexOf(':') + 2;
        XML = request.Substring(index, request.Length - index);
        XMLReceived = true;
    }
}

please provide help if you can this is really strange thing which I can't figure out by my self

Thanks.

Answer 1

Yes, this code has very good odds to hang in the Release build. The JIT optimizer doesn't know that the variable might be set to true by code outside of the method. You need to tell it that, like this:

public class RequestGAMELIST
{
    public volatile bool XMLReceived = false;
    // etc..
}

The volatile keyword ensures that the jitter won't store the variable value in a CPU register.

That solves your problem, it is still not the right way to do it. You should use an AutoResetEvent instead. It ensures that the thread responds to the variable change is quickly as possible. And most importantly, it lets the thread block so it doesn't burn any cpu cycles.

public class RequestGAMELIST
{
    public AutoResetEvent XMLReceived = new AutoResetEvent();

    public void ParseRequest( string request )
    {
        int index = request.IndexOf(':') + 2;
        XML = request.Substring(index, request.Length - index);
        XMLReceived.Set();
    }

}

In your thread:

    XMLReceived.WaitOne();
    GameEngine.ParseGameList( Request.GAMELIST.XML );

Answer 2

This is a bad idea:

while (!Request.GAMELIST.XMLReceived) ;

At least you should be doing something like:

while (!Request.GAMELIST.XMLReceived) {
  System.Threading.Thread.Sleep(100);  // Don't hog the CPU!
}

Your program runs fine in debug mode perhaps due to certain debug routines added inside the while loop which makes it run slower...