C / C++ / MFC

"The largest fire starts but with the smallest spark." - David Crow

Favorit.m_strFilter="User='"+myUser+"' AND Dokument='"+Number+"'";
Favorit.Open();
if(!Favorit.IsBOF())
{
    Favorit.MoveFirst();
    Favorit.Edit();
}
else
{
    Favorit.AddNew();
    Favorit.m_User=myUser;
    Favorit.m_Dokument=Number;
    Favorit.SetFieldNull(&(Favorit.m_Gelesen));
}
Favorit.m_Favorit=bChecked;
Favorit.Update();
Favorit.Close();

//{{AFX_FIELD(DBFavoriten, CRecordset)
CString m_Dokument;
CString m_User;
long    m_Favorit;
CTime   m_Gelesen;
//}}AFX_FIELD

DBFavoriten::DBFavoriten(CDatabase* pdb)
	: CRecordset(pdb)
{
	//{{AFX_FIELD_INIT(DBFavoriten)
	m_Dokument = _T("");
	m_User = _T("");
	m_Favorit = 0;
	m_nFields = 4;
	//}}AFX_FIELD_INIT
	m_nDefaultType = dynaset;
}

"The largest fire starts but with the smallest spark." - David Crow

bujji_bec wrote:

delete []p;

bujji_bec wrote:

delete []p; // this statement giving problem

led mike wrote:

it was allocated by whatever clsobj is and therefore should be cleaned up by that same class rather than user code.

Cedric Moonen wrote:

You can allocate memory inside a class a release it outside (in the mean function for example). I agree this is ugly and to be avoided by all means but that won't produce any error.

Cedric Moonen wrote:

In the context of a dll, it's different because your exe and the dll are two separate processes, so the heap managers are different. Everything that has been created by the dll has to be released by your dll and everything that has been created by your exe has to be released by your exe. If you mix that, you will get troubles

led mike wrote:

I have no idea what you mean with that statement. You can't "mix" memory addresses across processes because you don't have access to them. Therefore you can't get that "trouble".

bujji_bec wrote:

delete []p; // this statement giving problem

Cedric Moonen wrote:

A blue cow is getting out of the screen (this one is highly improbable I think ).

Cedric Moonen wrote:

A blue cow is getting out of the screen (this one is highly improbable I think ).

Chris Losinger wrote:

no no. this happened to me just two days ago. i was doing a delete [] on something i had allocated with HeapAlloc then resized with _realloc. the cow was pissed, and it broke my desk.

Roger Stoltz wrote:

You should have derived from CGrassEater instead of CVegetarian.Now you've made the CHolyCow angry!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Cedric Moonen wrote:

It is because the heap manager of your exe and of your dll are different, thus you CANNOT delete memory that has been allocated by your dll and vice-versa.

Cedric Moonen wrote:

t is because the heap manager of your exe and of your dll are different, thus you CANNOT delete memory that has been allocated by your dll and vice-versa.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

ThatsAlok wrote:

This problem arises in COM dll not normal DLL, as Memory allocation in Normal DLL is under the Excutable who is calling Function

Cedric Moonen wrote:

There are two heap managers: one for the exe and one for the dll.

The Process heap is used for allocating blocks if no other heap is used. Language 
run times also can create separate heaps within a process. (For example, C run time 
creates a heap of its own.) Besides these dedicated heaps, the application program or 
one of the many loaded dynamic-link libraries (DLLs) may create and use separate heaps.

led mike wrote:

There is one and only one default heap across an entire process.

MYDLL_API char* allocCharOnHeap()
{
	char* p = new char[12];
	ZeroMemory(p, sizeof(char)  * 12);
	strcpy(p, "Hello Heap");
	return p;
}

char* pFromDll = allocCharOnHeap();
TRACE("%s\r\n", pFromDll);
delete [] pFromDll;

m_hWndToolTip = ::CreateWindowEx(WS_EX_TOPMOST,<br />
                              TOOLTIPS_CLASS,<br />
                              NULL,<br />
                              TTS_NOPREFIX | TTS_ALWAYSTIP,<br />
                              CW_USEDEFAULT,<br />
                              CW_USEDEFAULT,<br />
                              CW_USEDEFAULT,<br />
                              CW_USEDEFAULT,<br />
                              m_hWnd,<br />
                              NULL,<br />
                              NULL,<br />
                              NULL);