.NET implementation of the active object pattern

Question

I'm looking for implementations of the active object pattern, but haven't for much so far. This is what I came up with:

• http://geekswithblogs.net/dbose/archive/2009/10/17/c-activeobject-runnable.aspx

Need something a little bit more involved. Preferably for .NET Version <= 3.5.

Answer 1

The simple implementation that uses System.Threading.Tasks.Task

class ActiveObject : IDisposable
{
    private Task _lastTask = Task.Factory.StartNew(() => { });

    public void Dispose()
    {
        if (_lastTask == null)
            return;

        _lastTask.Wait();
        _lastTask = null;
    }

    public void InvokeAsync(Action action)
    {
        if (_lastTask == null)
            throw new ObjectDisposedException(GetType().FullName);

        _lastTask = _lastTask.ContinueWith(t => action());
    }
}

InvokeAsync isn't thread-safe, use lock (_lastTask) lastTask = ...; if you need it.