Too many connections when developing

Question

I'm trying (with a lot of help from this community) to put together my first client/server app.

I am using Indy 10 and Delphi Xe2, but suspect my problem does not lie with those, but rather with how soockets work (wizardy and black arts, if you ask me).

Because I often hit breakpoints of exceptions and step through my code before pressing Alt+F2 to halt, my next runs often hit exception "already connected" and eventually I get "too many connections".

How can I tidy this up?

(also, does anyone have a demo which uses try ... except, ratehr than try ... finally as in the Indy demos?)

Answer 1

"already connected" occurs on the client side when you call Connect() while Connected() still returns true. That usually occurs if you disconnect and leave unread data in the IOHandler.InputBuffer. Try clearing the InputBuffer before reconnecting. This is commonly encountered, so a near-future update to Indy may address that issue.

"too many connections" means that you set the server's MaxConnections property to a positive non-zero value and that many simultaneous clients are already connected to the server when a new client tries to connect. If you do not think that you are making that many simultaneous connections, then it usually means that you are not managing the connections correctly in your server code so disconnected clients get cleaned up correctly. The most common cause of that is putting exception handlers in your code that catch and swallow Indy's internal exceptions to itself. If you do catch exceptions, be sure to re-raise any that derive from EIdException and let the server handle them internally.