Re: can event handler call event source passed as connection point parameter?

What's weird here is that if I do a redundant QueryInterface on the
pointer for its own type, the code runs normal! The code is similar to
following:

// event source in free threaded DLL
class CServer ... {
    Fire_OnSomeEvent(IServer* ptr) { // ATL generated
        ...
        HRESULT hr = Invoke(...);
        ...
    }

    SomeMethod() {}
};

// event handler in apartment threaded EXE
class CClient ... {
    void __stdcall OnSomeEvent(IServer * ptr) {
        ptr->QueryInterface(IID_IServer, (void**)&ptr); // line X
        ptr->SomeMethod(): // line Y
    }
};

With line X, everything works fine and line Y does call through
SomeMethod().
Without line X, I saw "0x0000005 access violation while writing" at
line Y if I turned on all exception for debugging, and the Invoke in
the Fire method returned 0x80010105.

Is this related to the threading issue? Any idea why line X workaround
the problem?

Thanks & regards,
Xudong

Igor Tandetnik wrote: