Bee Eee Blog

If you’ve ever used a message queue to talk to different parts of your application you know that sometimes you run into a problem with tangled call stacks; especially if one message can causes another message to be sent.

However, in c# .Net there is a simple way to untangle the call stack of the message queue. Just use the BeginInvoke method. This unwinds the stack and uses a delegate to call your message reception handler from the control’s thread.

For instance:

delegate void PostOfficeMessageHandler( POMessage message );

public void SendMessage(Control Sender, POMessage Message)
{
    PostOfficeMessageHandler mh = recipients[Sender];
    Sender.BeginInvoke(mh, Message);
}

The advantages of this method of deliver are two fold. 1. The stack is unwound. 2. It makes message handler in the control’s threads solving some threading issues.

There are a couple of disadvantages. 1. Extra overhead. 2. If the message causes problems you may not know where it’s coming from!