Multithreaded Problem

I think you have to give a little more information about what classes you are dealing with :

Is UpdateData() a non-static member of CProgram or is UpdateData() the one in class CWnd or ....

If member of CWnd, I would suggest you do like this :
pWndObject -> UpdataData(FALSE);

where pWndObject is a pointer to the object you want to operate on.

/JOlesen

/JOlesen

Yes, UpdateData() is a CWnd. This is exactly how that portion looks like:

UINT CProgram:oIt(LPVOID param)
{
CProgram* ptr = (CProgram*)param;
ptr->UpdateData(FALSE); // Errors Out Here

...
...
}

DoIt(LPVOID param) is a static private member function of CProgram. I invoked the function like this:

BOOL CProgram::OnInitDialog()
{
AfxBeginThread(&DoIt,(LPVOID)this,THREAD_PRIORITY_NORMAL);
...
}

So what's the problem?

So what's the problem? .... I simply don't know !

I just reviewed some old multithreaded code I wrote years ago, and I use exactly the same approach - only it wasn't MFC.
Could it be an MFC issue ?

After searching on Google, I found some warnings on using UpdateData() ... is this what you want to ?

Could you post the precise compiler errors ?
/JOlesen

Well if I just use UpdateData(FALSE), then I get a compiler error:

error C2352: 'CWnd::UpdateData' : illegal call of non-static member function
c:\program files\microsoft visual studio\vc98\mfc\include\afxwin.h(2230) : see declaration of 'UpdateData'

However, if I use ptr->UpdateData(FALSE), then I get a runtime error:

Debug Assertion Failed!
File: wincore.cpp
Line: 884

Oh, then it's not a compiler Error / problem.

You SHOULD use the latter method (ptr -> UpdateData()) !

There is something wrong with the way you use the class.
The Assert is put there (in WinCore.cpp) to protect against bad usage.
I am no expert on MFC, but I would try to debug your code right till the Assertion occurs - and see what's being tested and what fails.
MFC source code can be / is installed, so you should be able to debug all the way.
/JOlesen

Just looked into wincore.cpp and found this right after the assert :

CObject* p;
ASSERT((p = pMap->LookupPermanent(m_hWnd)) != NULL ||
(p = pMap->LookupTemporary(m_hWnd)) != NULL);
ASSERT((CWnd*)p == this); // must be us

// Note: if either of the above asserts fire and you are
// writing a multithreaded application, it is likely that
// you have passed a C++ object from one thread to another
// and have used that object in a way that was not intended.
// (only simple inline wrapper functions should be used)
//
// In general, CWnd objects should be passed by HWND from
// one thread to another. The receiving thread can wrap
// the HWND with a CWnd object by using CWnd::FromHandle.
//
// It is dangerous to pass C++ objects from one thread to
// another, unless the objects are designed to be used in
// such a manner.

This could give you an idea how to handle the problem.
/JOlesen

You can not call a static or private function from a thread. Even if the thead is defined in the class. Create another function called MyUpDate() as part of CProgram class. In DoIt() call CProgram->MyUpDate(). In MyUpDate() call UpdateData().

Ex:

BOOL CProgram::OnInitDialog()
{
AfxBeginThread(&DoIt,(LPVOID)this,THREAD_PRIORITY_NORMAL);
}

UINT CProgram:oIt(LPVOID param)
{
CProgram* ptr = (CProgram*)param;
ptr->MyUpDate(FALSE);
}

void MyUpDate(BOOL bUpDateType){
UpdateData(bUpDateType);
}

Problem solved.

Brother C

PS make MyUpDate() public or it will not work.

Dear BrotherC,

Indeed you can call a memberfunction from a thread belonging to the same class - no matter if the function being called is public, protected or private.
The only thing is that the function being called should be written in a way so it can handle this.

I am pretty sure TheCrappyProgrammer's problem is MFC - or rather the way MFC is being used.




/JOlesen