32bit client talking to a 64bit local server

Kannan Ramanathan

Is it possible to have a 32bit client initialize/invoke methods in a 64bit local COM server? If yes, how do I set up the Proxy/stub DLLs? The target OS I have in mind is Vista64 or Win7-64 (so the 32bit client will be running from with in WOW64). Also, can I go ahead with ATL 8 for implementing the above scenario? Any examples available online? Thanks.

Kannan Ramanathan

One more req I have to worry abt: The 64bit local server should be able to implement connection points (32bit client being the sink)...is this possible? Thanks.

Stuart Dootson

This thread[^] documents the opposite scenario (64-bit client, 32-bit server) - does that enlighten the situation at all? And this thread[^] indicates that 32-bit client and 64-bit client should be OK.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Kannan Ramanathan

Thanks Stuart for the pointers. Looks like all I need to do is to build/register both 32bit and 64bit proxy/stubs. Is that right? In this case, can I also make the 32bit code act as a sink? Thanks.

Stuart Dootson

Ummmm - yes, no, maybe - I really don't know :-O

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Kannan Ramanathan

I did a quick check using ATLDUCK sample. Built the atlduck (local com server) in to 64bit, tried connecting to it from duck (32bit). CoCreateInstance worked perfectly, but when duck tried an Advise() to atlduck, it crashed with an error msg "runtime terminated the app" :sigh: ... trying out some more experiments, will update on the results.

Kannan Ramanathan

Pk, I am stuck with the error - "duck.exe - An application has requested the Runtime to terminate it in an unusual way". This error comes up whenever the client tries to do an Advise(). I remember seeing this issue in XP (during the VS.NET 2002 days) by installing an hotfix...but, my current testbed is Win7-64..any ideas why this error is coming? BTW, are there any samples available that do this kind of 32 => 64 => 32bit calls/event_triggers? I am not able to find any (or prob I miss the key words in my search! :( )...Thanks.

Kannan Ramanathan

I have got it working. The error was because of me registering a 32bit server stub (my bad!!)...thanks. :)

Stuart Dootson

Nice, well done. Maybe a short article on the subject would be useful, to help out other people facing the same issue?

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Kannan Ramanathan

sure will do, once I am done with my current legacy => 64bit port. Thanks.