COM Discussion Boards

Re: SIngletons, Threading, and Marshalling

15-Dec-01 6:12

Yes, you need to synchronize method and property in your object with Semaphore
and critical section (your choice...). I did the same thing with a Local server
Component and it works really fine.

Not Active15-Dec-01 9:30

Not Active

15-Dec-01 9:30

Thanks, but my questions were about marshaling not synchronization. I don't see synchronization as an issue since the object is single-threaded. Obviously a multi-threaded object would require it.

COM & Duel Processors

Ancient Dragon13-Dec-01 13:06

Ancient Dragon

13-Dec-01 13:06

I have an apartmented ATL server program running on W2K at work. Now mangement has decided to run it on a fancy, spaning new machine with 1 gig ram, dual processors, and 4 90-gig hard drives.

Question: is it possible to change to server program to take advantage of the dual-processing capabilities? If it is, how? Is there a book or white paper some place that explains how to do that ?

Re: COM & Duel Processors

Ganesh Ramaswamy19-Dec-01 5:24

Ganesh Ramaswamy

19-Dec-01 5:24

just install windows2000 adn make it recognize that the server runs on dual processor. thats it. It will take care. Yes. there are ways in win32 in which u can use the dual processor feature and control them. But then that will defeat the idea on COMponent at all, because it will becomes windows proprietary

Ganesh Ramaswamy

CoInitializeEx ( )

Tim Rymer13-Dec-01 4:12

13-Dec-01 4:12

I've created an ActiveX control with VC++ 6.0, and i try to call CoInitializeEx() at the beginning of a worker thread, but it doesnt recognize the API, and all I get is an undeclared identifier error for that
and COINIT_MULTITHREADED;

I linked to "ole32.lib" and i threw in <objbase.h> in for kicks at the top of the .cpp and in a separate case, the .h

I AM LIKE ----------------| |-------------------
^
THIS CLOSE

to getting this crap... i dont have a clue... i've running the project on a different machine as well and i get the same errors. i've tried to throw in just about every other library as well... am i missing a library? Could someone show me what libraries they link to in a project that works? Any suggestions would be so helpful...

Thanks,

~Tim

SHABBA!!

Michael P Butler13-Dec-01 5:11

Michael P Butler

13-Dec-01 5:11

CoInitializeEx requires either NT 4.x or greater or Win 98 (Win 95 with DCOM).

Try either #define _WIN32_DCOM or #define WIN32_WINNT 0x0400.

Michael Smile | :)

Ernest Laurentin13-Dec-01 5:38

13-Dec-01 5:38

If you are using ATL, in your Stdafx.h
make sure sure have before all includes

#define STRICT
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0400
#endif
#define _ATL_FREE_THREADED	//_ATL_APARTMENT_THREADED

Make sure your WinMain look like this, you need CLSCTX_LOCAL_SERVER
if you are using a local server.

extern "C" int WINAPI _tWinMain(HINSTANCE hInstance, 
    HINSTANCE /*hPrevInstance*/, LPTSTR lpCmdLine, int /*nShowCmd*/)
{
    lpCmdLine = GetCommandLine(); //this line necessary for _ATL_MIN_CRT

#if _WIN32_WINNT >= 0x0400 & defined(_ATL_FREE_THREADED)
    HRESULT hRes = CoInitializeEx(NULL, COINIT_MULTITHREADED);
#else
    HRESULT hRes = CoInitialize(NULL);
#endif
// .. some lines there in ATL
    if (bRun)
    {
        _Module.StartMonitor();
#if _WIN32_WINNT >= 0x0400 & defined(_ATL_FREE_THREADED)
        hRes = _Module.RegisterClassObjects(CLSCTX_LOCAL_SERVER, 
            REGCLS_MULTIPLEUSE | REGCLS_SUSPENDED);
        _ASSERTE(SUCCEEDED(hRes));
        hRes = CoResumeClassObjects();
#else
        hRes = _Module.RegisterClassObjects(CLSCTX_LOCAL_SERVER, 
            REGCLS_MULTIPLEUSE);
#endif
        _ASSERTE(SUCCEEDED(hRes));

        MSG msg;
        while (GetMessage(&msg, 0, 0, 0))
            DispatchMessage(&msg);

        _Module.RevokeClassObjects();
        Sleep(dwPause); //wait for any threads to finish
    }

    _Module.Term();
    CoUninitialize();
    return nRet;
}

Tim Rymer13-Dec-01 10:08

13-Dec-01 10:08

Sweet guys! that definitely fixed it.

Now on to our next question... (the next thread) Big Grin | :-D

SHABBA!!

Tim Rymer13-Dec-01 10:33

13-Dec-01 10:33

er... we'll do it right here...

ok... It goes through all of the many events raised, and then when it gets to the last one, it'll crash. hmm... it crashes in COleDispatchDriver::InvokeHelperV 's call to
COleDispatchDriver::Invoke... then it goes into assembly.(grr)

(it's referencing something with nothing in it (0x000005)

Has anyone had an error similar to that?

I'm pretty darn sure i'm not wiping anything out before that last event finishes... i really need this last event too...<sigh>

I hope you guys have had this happen to you as well, and just so you know, the events are sent to a VB app... i'm sure y'all knew that though. Not as much stress on me now, but it's still lingering...

Help!! Thanks, people! Learnin' from the best I guess!

~Tim

SHABBA!!

Ernest Laurentin13-Dec-01 11:26

13-Dec-01 11:26

Happy to know that you finally made it!
The only reason I can see is that you are calling that function with
invalid arguments (why the other event function crash?)
If you were using an old client with VB, you may need to rebuild your
VB client.
Give a sample of your code, people will help you faster!

Tim Rymer14-Dec-01 6:45

14-Dec-01 6:45

ok here comes the sample:

I have my MFC ActiveX Full Control (according to VC++ 6.0 Wizard).

//Which Calls:

CESpyderCtl::Start() {
//oh, and i call CoInitializeEx(NULL, COINIT_MULTITHREADED)
// in CESpyderApp::InitInstance() also, but i dont know what runs first...
// havent tried to find out. *shrug*

_beginthread(...)

//err checking
}

//Begin Thread Calls a global function called:
void gStart(void *spy) {
//which ultimately calls Parse() that fires an event pretty often
//so it can update a color box to show what it's doing.

CoInitializeEx(NULL, COINIT_MULTITHREADED); //i call this in
//CESpyderApp::InitInstance() as well.

Parse();
CoInitializeEx(NULL, COINIT_MULTITHREADED);
}

//So inside of Parse(); we've got this
int CESpyder::Parse() {

//parse a file
Fire_StatusChange(STAT_SEARCHING); //events are status changes
//connecting, adding, searching, error, and done.

//and on the last one, it's doing the same thing, and i'm firing a done event.
Fire_StatusChange(STAT_DONE);
//i also fire a separate done event, but it never gets to it, and i've also tried to just fire a done event, but it crashes the same way.
Fire_Done();
return 1;

}

I figure this still wont give you enough information, i've tried putting
Sleep()'s all over the place.., but it seems like it doesnt affect it...
<sigh>, i'm using apartment threading, if i remember correctly it wont let me pick apartment or free threaded. i think i even tried doing ATL but free was greyed out... either way i dont know how to Fire events in VC with an ATL object... (you could show me that, but i'll never be able to get rid of this thing that will eat at my soul for eternity... haha!

Thanks,

~Tim

SHABBA!!

Ernest Laurentin14-Dec-01 11:00

14-Dec-01 11:00

Sorry if I can't help you. All I can tell you is your bug
is maybe related to MFC. I always use ATL to develop ActiveX control.
I know MFC has a macro, I think it's: AFX_MANAGE_STATE( ), where I have
seen developer using: AFX_MANAGE_STATE(AfxGetStaticModuleState( ));
but again I have never use it. Do you always fire event from the same thread?
What's the other thread is doing?

Tim Rymer17-Dec-01 5:59

17-Dec-01 5:59

i tried throwing that in there to no avail, but i went and searched for firing events from worker threads with AFX_MANAGE_STATE in there as well and found some stuff, so i'm working on trying one of those out right at this moment..

do you think you could show me how to raise an event from C++ using an ATL control ? (for kicks i can try it through ATL and see how well it works then)

~Timothy T. Rymer

www.digipen.edu
tim.xpertz.com

Ernest Laurentin17-Dec-01 6:50

17-Dec-01 6:50

Okay I will send you an example how I did something similar.

Ernest Laurentin17-Dec-01 10:31

17-Dec-01 10:31

I made a simple demo for you. I sent it to your email at:
heaven_bounty@yahoo.com
Let me know if it helps you!

Tim Rymer18-Dec-01 6:11

18-Dec-01 6:11

That's what baffles me is that it's the exact same idea except that it's in an MFC ActiveX Control...

here's my question:

1. Make a new COM ATL Project.
-I picked FULL CONTROL when i made a new ATL obj... I assume that to be fine.
-Do i want to merge proxy/stub code?
-Support Connection points, of course
-Apartment threading (it wont let you choose Free if you choose to make a
control) so... should i just be making an ATL object and wrap it in a Control?
-Do i need to check free threaded marshalling?(i assumed so)
-Aggregation: (No) i have no clue what this does... i've basically learned COM/ATL/ActiveX from common lingo and trial and error.

2. ok after all of that is done, (the real question is coming, i promise)
- I compile,
- Implement Connection points? I cannot compile to where i can call events in the code and it doesnt show up (like the way you have it in CProxy...).

that's my dilemma. oh and when i try to add a function to the CProxy_... i get: "The implementation file for class CProxy_ITesterEvents<class t=""> cannot be found" ---- what am i not doing, that i should be doing??

well, that's all for now, i'm gonna keep messing with it. RSVP

~Timothy T. Rymer

www.digipen.edu
tim.xpertz.com

Ernest Laurentin18-Dec-01 7:03

18-Dec-01 7:03

1) Make a new COM ATL Project [ ok ]
- Picked Full .. [ ok ]
- Attributes: Apartment, Dual, Aggregation: Yes [or No] doesn't matter for now
- Connection points [x], Error Info [ ] (no, or I don't mind), Free Thread [ ] (no, I don't
mind, that's not the cause of your problem).
- Select settings for Miscellaneous, Stock Properties [ ok ]
2) Build your project, It should build fine (very important, must work)
3) Add event function to your connection point, right-click "_YourObjectEvents" and select
Add Method ( I am sure you did everything correctly so far...)
4) Verify that you have COM_INTERFACE_ENTRY(IConnectionPointContainer) in your COM_MAP
5) Implement the connection point:
- right-click your "YourObjectClass", chose "Implement Connection Point..."
- check your "_YourObjectEvents" and Click Ok
6) At that point, the proxy stub will be added for you, if you don't see it. You must have
it already on your folder. You may want to delete previous proxy stub class (files) every
time you add a new method (event) to your connection point.
7) Follow the example in the thread function that I sent you.

Tim Rymer18-Dec-01 7:23

18-Dec-01 7:23

cool, ok that's what i've been doing. now after i implement the connection points i get an error:

BEGIN_CONNECTION_POINT_MAP(Ccrap)
CONNECTION_POINT_ENTRY(IID_IPropertyNotifySink)
CONNECTION_POINT_ENTRY(IID__IcrapEvents)
END_CONNECTION_POINT_MAP()

it says that IID_IcrapEvents is undeclared... any clue about that?
also, when it asked me if i wanted a .dll or exe it also had a Checkbox that asked if you wanted to merge proxy/stub code. Is that necessary?

~Timothy T. Rymer

www.digipen.edu
tim.xpertz.com

Ernest Laurentin18-Dec-01 7:48