C / C++ / MFC

16-Apr-10 7:42

Message Removed

Maximilien16-Apr-10 7:45

Maximilien

16-Apr-10 7:45

What is not working ? Compilation errors/warnings ? wrong values ? crash ?

Is it a typo that your first include line is commented out ?

Watched code never compiles.

aruneshjoshi16-Apr-10 7:53

16-Apr-10 7:53

no the code is compiling in visual studio but it got stuck i am working on this from past 2 days and ots not working that the producer is producing but consumer is not consuming and according to logic it must be random but when producer produces 10 times code get halt and no consumer work i am very new to this language if you can help then it will be appreciated....
please help

loyal ginger16-Apr-10 7:54

loyal ginger

16-Apr-10 7:54

It may help if you post your code using "code block" style with proper indention -- something like this

int main()
{
    int buffer[NUM]; 
    int start; //index of the first element a consumer has to consume
    int end; //index of the first free position in the buffer
    int PTemp; //the new element the producer has to insert in the buffer
    int CTemp;
    int full,empty;
    int dataNum; //number of data in the buffer
    int np,nc,finished;
    double time_start;

    PTemp=CTemp=start=end=full=dataNum=np=nc=finished=0;
    empty=1;
    ....
}

People will be more willing to read your code like this than what you posted.

aruneshjoshi16-Apr-10 8:06

16-Apr-10 8:06

hello i am new to this so sorry for that but if you can correct it then it will be a great help i have even made the win32 threads code of this producer consumer problem in c++ which is working but open mp one is not working so help me in this if you want then i can even post the win32 threads code

David Crow16-Apr-10 8:29

David Crow

16-Apr-10 8:29

aruneshjoshi wrote:
#pragma omp section nowait //producer's code

Should this be:

#pragma omp sections nowait // producer's code

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Man who follows car will be exhausted." - Confucius

aruneshjoshi16-Apr-10 8:44

16-Apr-10 8:44

thanks for your help but still code is not working

Allocation/Deallocation from Memory Pool [Solved]

rchrd16-Apr-10 9:26

rchrd

16-Apr-10 9:26

You might get the help you need if you join the OpenMP forums and post your question there. All the best OpenMP experts are there to help you, including the folks who created the OpenMP API.

http://openmp.org/forum/[^]

Skippums16-Apr-10 4:17

Skippums

16-Apr-10 4:17

I am wondering if the type passed to delete[] needs to be the same as the type allocated by new? I am attempting to do the following:

void**  memPoolPtrs = new void* [4 * (1 + 12)];
double* memPoolData = new double[4 * 12 * 30];
double*** myData = reinterpret_cast<double***>(memPoolPtrs);
memPoolPtrs += 4;
for (size_t idx0 = 0; idx0 < 4; ++idx0) {
    myData[idx0] = reinterpret_cast<double**>(memPoolPtrs);
    memPoolPtrs += 12;
    for (size_t idx1 = 0; idx1 < 12; ++idx1) {
        myData[idx0][idx1] = memPoolData;
        memPoolData += 30;
    }
}

// Do some stuff with myData

delete[] **myData; // Delete ALL dynamically allocated doubles
delete[]   myData; // Delete ALL dynamically allocated pointers

Is there any risk in the above approach (other than allocating things of improper size)? I can't think of a reason why such a thing wouldn't work, but I am curious if the two delete statements will work as I anticipate. Thanks,

Sounds like somebody's got a case of the Mondays

-Jeff

modified on Friday, April 16, 2010 12:41 PM

Re: Allocation/Deallocation from Memory Pool

«_Superman_»16-Apr-10 6:41

«_Superman_»

16-Apr-10 6:41

Since the delete operator takes a void* type, it doesn't matter what type is passed for deletion as long as it is the starting address of the allocation.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Re: Allocation/Deallocation from Memory Pool [Solved]

cmk16-Apr-10 9:06

cmk

16-Apr-10 9:06

For yor case it works.

As a general rule it won't.

delete[] against an object, whose type has a destructor will call the 'vector deleting destructor', which will call the destructor for each element.

The problem is the number of elements.

When new[] is called on a type with a destructor:
1. malloc a block large enough to hold the reqested # of elements, the actual block size will be rounded up to some grain size.
2. store the actual block size (bytes) with the block for free().
3. store the requested # of elements with the block so delete[] can iterate over them and call ~().

When you call delete on a different (sized) type the # of elements stored with the block will be wrong and you will either call ~() on too few or too many elements.

If too few then you could have a memory leak if the destructor frees resources.

If too many then you corrupt the heap.

...cmk

The idea that I can be presented with a problem, set out to logically solve it with the tools at hand, and wind up with a program that could not be legally used because someone else followed the same logical steps some years ago and filed for a patent on it is horrifying.
- John Carmack

Re: Allocation/Deallocation from Memory Pool [Solved]

Gwenio16-Apr-10 9:21

Gwenio

16-Apr-10 9:21

Yes if the destructor is not virtual, no if it is. Delete will take any type, but it will only call the appropriate destructor if it is virtual or if you pass it as the correct type.

Can we Insert table into SDI Application ?

Khathar16-Apr-10 1:54

Khathar

16-Apr-10 1:54

dear all,

i have created one SDI application and i need to include one table (just like how we insert table into ms word document).

is it possible? if yes please let me know..

thanks in advance.

AK

Re: Can we Insert table into SDI Application ?

Maximilien16-Apr-10 2:50

Maximilien

16-Apr-10 2:50

Khathar wrote:
is it possible? if yes please let me know..

Yes it's possible.

have a look at MFC Grid control 2.26[^].

Watched code never compiles.

Re: Can we Insert table into SDI Application ?

«_Superman_»16-Apr-10 6:47

«_Superman_»

16-Apr-10 6:47

You can do this by making the view of the SDI application a rich edit view.
Take a look at this wonderful article - CRichEditControl50W - A VC++ Rich Text Edit 4.1 MFC Control[^]

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

CComboBox the max text length ??

Arrin16-Apr-10 0:28

Arrin

16-Apr-10 0:28

Hello,
i try to write large text in to CComboBox field, but the max text length is limited by the CComboBox width !!! Frown | :(

But i need to imput larger text as the width of the combo box, when i write my text, the cursor moves to the right!!??
If i read large string from a file, this can be showed in the combo box, only if i try to write them by my self its limited!?
Can any one help me how to solve this?? Frown | :(

Thanx for any help!
Arrin

Re: CComboBox the max text length ?? SOLVED

Arrin16-Apr-10 0:43

Arrin

16-Apr-10 0:43

Sorry
i solve this, Frown | :(

its simple setting on the properties CBS_AUTOHSCROLL Frown | :(

Arrin

Worker Thread GUI

MsmVc15-Apr-10 22:21

MsmVc

15-Apr-10 22:21

Hi All

I am useing worker thread in Dialog base Application.In Dialog I have a Static Control and Button.I try to set some values in Static Control.I have got some GUI Error application and CtlColor color change auto.As well as Control move from fixed position.I am doing like this

CWinThread *Testing;
UINT InsertThread ( LPVOID p );
UINT InsertThread ( LPVOID p )
{
CTestDlg *Get=( CTestDlg *)p;
	Get->Example();
	
	return 0;
}

void CTestDlg::OnBnClickedButton4()
{
Test = AfxBeginThread(InsertThread, (LPVOID) this,THREAD_PRIORITY_NORMAL,0,0);
}
void CTestDlg:: Example()
{
//m_showvalues->Member variable of CStatic Control
int count=0;
		
For(int i=0;i<10000;i++)
{
Count++;
CString show="";
show.Format("%d",count);
m_showvalues.SetWindowText(show);
}
}

I also use

OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor) and OnEraseBkgnd(CDC* pDC)

for change background color(Dialog and CtlColor).

How can i solve GUI Problem?
Please help me.

Cedric Moonen15-Apr-10 22:33

Cedric Moonen

15-Apr-10 22:33

MsmVc wrote:
How can i solve GUI Problem?

Never never access GUI elements in another thread than the GUI thread. This is a recipe for disaster. One way to solve your problem is instead to access the static control directly in your thread, you simply send a user defined message to your dialog. In the handler of this message, you update your control. This way, this is the UI thread that still accesses the control. More info and examples here[^]

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

Eugen Podsypalnikov15-Apr-10 22:44

Eugen Podsypalnikov

15-Apr-10 22:44

MsmVc wrote:
How can i solve GUI Problem?

You could pass the HDC and the client rectangle of the static control at your thread
to draw (only) there from the thread directly... Smile | :)

virtual void BeHappy() = 0;

MsmVc15-Apr-10 23:07

MsmVc

15-Apr-10 23:07

can you give me some example?

Re: Worker Thread GUI [modified]

Cedric Moonen15-Apr-10 23:17

Cedric Moonen

15-Apr-10 23:17

If you would have taken the time to look at the article I linked to, you could see that there's an example in the section "Worker threads and the GUI II: Don't touch the GUI".
It's been a while that you are posting questions about threads and you still miss some basic concepts. Don't you think it could be interesting for you to read some good article (like the one I linked to you) about the subject ? Otherwise, you'll come asking questions here again and again and never really learn how to do it the proper way.

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

Eugen Podsypalnikov15-Apr-10 23:38

Eugen Podsypalnikov

15-Apr-10 23:38

Try it

class CCtrlDrawContext
{
  CClientDC* m_pcCtrlDC;
  CRect      m_cCtrlRect;
public:
  CCtrlDrawContext(CClientDC* pcDC, const CRect& cRect);
  ~CCtrlDrawContext();
  
  const CRect& GetRect() { return m_cCtrlRect; };
  CDC* GetDC() { return m_pcCtrlDC; };
};
  
CCtrlDrawContext::CCtrlDrawContext(CClientDC* pcDC, const CRect& cRect)
: m_pcCtrlDC(pcDC), m_cCtrlRect(cRect)
{
}
  
CCtrlDrawContext::~CCtrlDrawContext()
{
  delete m_pcCtrlDC;
  m_pcCtrlDC = NULL;
}
  
...
/*afx_msg*/ void CYourDialog::OnButtonClick()
{
  CRect cStaticRect;
  m_cwndStatic.GetClientRect(cStaticRect);
  AfxBeginThread((AFX_THREADPROC) ThreadLoop,
                 new CCtrlDrawContext(new CClientDC(&m_cwndStatic),
                                                    cStaticRect));
}
  
/*static*/ UINT CYourDialog::ThreadLoop(LPVOID lpParam)
{
  if (lpParam) {
    CCtrlDrawContext* pcContext = (CCtrlDrawContext*) lpParam;
    for (int i = 0; i < 10; ++) {
      pcContext->GetDC()->FillSolidRect(pcContext->GetRect(),
                                        i % 2 ?
                                        RGB(0, 200, 128) :
                                        RGB(0, 255, 0));
      ::GdiFlush();
      ::Sleep(500);
    }
    delete pcContext;
    pcContext = NULL;
  }
}

virtual void BeHappy() = 0;

modified on Friday, April 16, 2010 6:22 AM

Eugen Podsypalnikov16-Apr-10 0:21

Eugen Podsypalnikov

16-Apr-10 0:21

An improvement: place ::GdiFlush();
after the drawing step in your loop Smile | :)

virtual void BeHappy() = 0;