CODEWITHSUNDEEP
c#console
bendewey
bendewey

Reputation: 40265

How do i prevent a StackOverflow error in the following code?

I have the follwing code that provides an auto refresh feature to a WCF Console Hosted Application.

When the Console.ReadKey accepts an invalid character, it restarts the ReadKey method. If the user mashes the keyboard long enough on this code it will go into a StackOverflowException.

Does anyone have a way to re-write this code so that it doesn't cause the stack to blow?

[STAThread]
static void Main(string[] args)
{
    bool restart = true;
    while(restart)
    {
        using (var myWcfHost = new MyWcfHost())
        {
            myWcfHost.start();

            Console.WriteLine("Press Enter to quit or Ctrl+R to restart");

            restart = WaitForRestart();
        }
    }
}

private static bool WaitForRestart()
{
    // clear users input
    Console.CursorLeft = 0;
    Console.Write(' ');
    Console.CursorLeft = 0;

    // read users input
    var key = Console.ReadKey();
    if ((key.Modifiers & ConsoleModifiers.Control) != 0
        && key.Key == ConsoleKey.R)
    {
        // refersh the settings
        ConfigurationManager.RefreshSection("appSettings");
        return true;
    }
    if (key.Key == ConsoleKey.Enter || key.Key == ConsoleKey.Escape)
    {
        return false;
    }
    return WaitForRestart();
}

Upvotes: 1

Views: 216

Answers (2)

flatline
flatline

Reputation: 42633

It looks like each time there's an invalid key pressed, you push another WaitForRestart onto the stack, eventually resulting in an overflow exception. I think this would fix:

private static bool WaitForRestart()
{
// clear users input
Console.CursorLeft = 0;
Console.Write(' ');
Console.CursorLeft = 0;


while (true) 
{
    // read users input
    var key = Console.ReadKey();
    if ((key.Modifiers & ConsoleModifiers.Control) != 0
        && key.Key == ConsoleKey.R)
    {
        // refersh the settings
        ConfigurationManager.RefreshSection("appSettings");
        return true;
    }
    if (key.Key == ConsoleKey.Enter || key.Key == ConsoleKey.Escape)
    {
        return false;
    }
}
}

Upvotes: 0

Eddie
Eddie

Reputation: 54431

Replace recursion with a loop:

private static bool WaitForRestart()
{
    while (true)
    {
        // clear users input
        Console.CursorLeft = 0;
        Console.Write(' ');
        Console.CursorLeft = 0;

        // read users input
        var key = Console.ReadKey();
        if ((key.Modifiers & ConsoleModifiers.Control) != 0
            && key.Key == ConsoleKey.R)
        {
            // refersh the settings
            ConfigurationManager.RefreshSection("appSettings");
            return true;
        }
        if (key.Key == ConsoleKey.Enter || key.Key == ConsoleKey.Escape)
        {
            return false;
        }
    }
}

Upvotes: 3

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