sockets: How to know when your data is sent

[Gandalf]

>Woah!  This is all enlightening news to me.  Of course, what little
>bit of socket level stuff I've done, I've always had a
>"send/acknowledge" type protocol wrapped around.  I guess I've just
>been lucky so far :-).
>
Oh yeah. I did the same and I realized that the response time can be 
very long.
I had to reconsider my protocol, and use as few send/ack pairs as possible.
No matter if you have a broadband connection or not - it can be VERY slow
if your protocol uses many send/ack pairs.