Type-Strong Asynchronous Execution

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Introduction

This static class allows the programmer to run a method asynchronously with a single line of code with typed arguments.

Background

Sometimes, a programmer just want some work to be done in the background, and the .NET framework provides several ways of doing just that. You can start a thread and make it call a function, or you can use the ThreadPool.QueueUserWorkItem, but I always felt it was kind of messy. Using ThreadPool forces you to use a WaitCallback delegate if you want to specify any parameters, these need to be boxed into an object and unboxed in the WaitCallback function called.

So, what I wanted was a simple function to call, Util.RunAsync(function, arg1,arg2,arg3...), in a sort of fire and forget way.

Using the Code

The static class Util contains an overloaded function called RunAsync. It is used as such:

public static void Main(string[] args)
{
    string someString = "Hello There";
    int someInteger = 42;
    DateTime someTime = DateTime.Now;

    Util.RunAsync(Function1, someString, someInteger, someTime);
}

public static void Function1(string aString, int anInteger, DateTime time)
{
    Console.WriteLine("{0} {1} {2}", aString, anInteger, time);
}

Points of Interest

The functionality is achieved using the ThreadPool.QueueUserWorkItem the function, and its arguments are wrapped in an ActionJob object that has a subclass for each amount of arguments usable with Util.RunSync. Because it is based on the Action delegate and the generic versions of it Action<T>, Action<T,V>, Action<T,V,X>, and Action<T,V,X,Y>, it can only execute functions with at most four arguments.

You should be able to change the code to work as a Work Queue for invoking with Windows Forms. Instead of running ThreadPool.QueueUserWorkItem, you could do something like this:

public static void DoInvoke<T, V, X, Y>(
              this System.Windows.Forms.Control control, 
              Action<T, V, X, Y> function, T a, V b, X c, Y d)
{
    if (control.InvokeRequired)
    {
        control.Invoke(function, a, b, c, d);
    }
    else
    {
        function(a, b, c, d);
    }
}

Conclusion

That's it. I like this little convenience, and I hope you do too :)

History

• 5 January 2008: Article submitted.