dde?

[Roger Abbott]

"Werner Schiendl" <ws-news at gmx.at> wrote in message news:<3b9631aa$0$28956$6e365a64 at newsreader02.highway.telekom.at>...
> Hi,
> 
> >
> > 3. DDE has a number of potentially crippling faults, but it is quite wrong
> > to describe it as a damaging zombie.  When used correctly, it works
> > extremely well.
> >
> 
> On Win32 platforms (that is, everything from Win95 and WinNT upwards) this
> is not correct.
> A single running application in the system (note: ANY application in the
> system, not just the client or the server application in question) that does
> not properly process DDE messages in its message loop can easily BLOCK the
> whole DDE system and you will wait for your DDE call to be completed
> forever.

Actually, its not a question of whether it process DDE messages
correctly, but whether it is processing any messages at all. The
default processing of DDE messages is correct. The problem is with
establishing a DDE converstion. The system does HWND_BROADCAST with
SendMessage to all top level windows, and if one of them is not taking
its messages off the queue the app trying to connect is blocked.

As I see it, all MS need to do is use SendMessageTimeout instead of
SendMessage, but asking MS to fix bugs is asking too much.

Roger Abbott,
RHA (Minisystems) Ltd.
http://www.rhaminisys.com
DDE ActiveX controls and FAQ
Other Freeware and Shareware

> There is an article on MSDN about that and how it is caused in detail, but
> unfortunately I do not have the number in my memory.
> 
> Anyway, I would agree with Alex' choice of terms :-)
> 
> best regards
> Werner