Using Async Delegates instead of the Thread class

If you want to write some asnychronous code, the good old fashioned way is to create a new Thread. But this has several pitfalls, e.g. when you need to use parameters or you need to retrieve a return value. Then this way is getting tricky.

Have a look at this solution that is using async delegates instead of the Thread class.

private delegate bool ThreadDelegate(int counter, int sleep);

/// <summary>
/// Thread Method.
/// </summary>
public static bool ThreadMethod(int counter, int sleep)
{
    for (int x = counter; x > 0; x--)
    {
        Console.WriteLine("Sleeping " + sleep + "ms");
        Thread.Sleep(sleep);
    }
    
    return true;
}

/// <summary>
/// Main Thread
/// </summary>
static void Main()
{
    ThreadDelegate threadDelegate = ThreadMethod;
    
    IAsyncResult result = threadDelegate.BeginInvoke(10, 200, null, null);
    // do something between BeginInvoke and EndInvoke
    bool threadResult = threadDelegate.EndInvoke(result);
    
    Console.WriteLine("Result " + threadResult);
}


And now the opposite, the solution that is using the Thread class.

/// <summary>
/// Thread Arguments
/// </summary>
class ThreadArguments
{
    public int counter;
    public int sleep;
    
    public bool result;
}

/// <summary>
/// Thread method
/// </summary>
public static void ThreadMethod(object argument)
{
    ThreadArguments ta = (ThreadArguments) argument;
    for (int x = ta.counter; x > 0; x--)
    {
        Console.WriteLine("Sleeping " + ta.sleep + "ms");
        Thread.Sleep(ta.sleep);
    }
    
    ta.result = true;
}

/// <summary>
/// Main Thread
/// </summary>
static void Main()
{
    ThreadArguments ta = new ThreadArguments();
    ta.counter = 10;
    ta.sleep = 200;
    
    Thread thread = new Thread(ThreadMethod);
    thread.Start(ta);
    thread.Join();
    
    Console.WriteLine("Result " + ta.result);
}


As you can see, that’s not really a nice solution to do such things, because you have to create a separated class to pass the parameters to the thread function. I think the better solution is the first one that is using async delegates.

I hope that I could deliver you some new insights about async delegates and threads.
- Gerhard

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