[prev in list] [next in list] [prev in thread] [next in thread] 

List:       wine-devel
Subject:    Re: DDE and postmessage
From:       eric pouech <eric.pouech () wanadoo ! fr>
Date:       2001-09-18 20:54:26
[Download RAW message or body]

Alexandre Julliard wrote:
> 
> eric pouech <eric.pouech@wanadoo.fr> writes:
> 
> > I've started looking at the inter-process DDE message management
> > as of today, PostMessage doesn't use the packing strategy used by
> > SendMessage (rightfully because of possible dangling pointer issue
> > if pointers are used in message parameters)
> >
> > however, some DDE messages need to send additional information
> > even when posting (copying all data), and DDE protocol requires
> > posting messages (SendMessage is banned)
> >
> > do you have any plan to handle this ?
> 
> I don't really have any plan yet. We clearly need to do a special case
> for posted DDE messages; a possibility would be to use an internal
> message with SendMessage to send the data across before posting the
> actual DDE message. There is an undocumented message similar to
> WM_COPYDATA that can be used to transfer a global memory block across
> processes, which is used for stuff like WM_DROPFILES; it doesn't work
> right now but I'm planning to implement it soon. This would add a
> synchronisation point that may defeat the purpose of the PostMessage
> though. If this is a problem we can probably add a DDE-specific server
> call to transfer the data
what I had in mind was somehow reusing the message packing capabilities
of SendMessage for PostMessage. Moreover, we need to handle large
memory chunks to be exchanged in SendMessage, so we could kill two birds
with one stone.

A+

-- 
---------------
Eric Pouech (http://perso.wanadoo.fr/eric.pouech/)
"The future will be better tomorrow", Vice President Dan Quayle

[prev in list] [next in list] [prev in thread] [next in thread]