C / C++ / MFC

17-Jul-08 1:59

I am trying to create a progress dialog box in the below event. But Progress dialog box is not displayed, it is working fine when I comment th loop, I the lenthy operation is very much similar to the loop.
I want the progressbar to be initiated with thread,
Please advice.

void CTestDlg::OnStartPrg()
{
ThreadPrgIndiaction* pThread;
pThread = new ThreadPrgIndiaction();
pThread->CreateThread();
pThread->PostThreadMessage(WM_MYTHREADMESSAGE,NULL,NULL);
// My progress is similar to below loop
int j=1;
while(j<99)
{
j++;
Sleep(200);
}
}

THREAD

BEGIN_MESSAGE_MAP(ThreadPrgIndiaction, CWinThread)
//{{AFX_MSG_MAP(ThreadPrgIndiaction)
// NOTE - the ClassWizard will add and remove mapping macros here.
ON_THREAD_MESSAGE ( WM_MYTHREADMESSAGE, MyMessageHandler )
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

void ThreadPrgIndiaction::MyMessageHandler(WPARAM, LPARAM)
{
CPrgDlg *dlg;
dlg = new CPrgDlg;
dlg->Create(IDD_DIALOG2);
dlg->ShowWindow(1);

PrgDialog

BOOL CPrgDlg::OnInitDialog()
{
CDialog::OnInitDialog();

// TODO: Add extra initialization here

m_prg.SetStep(1);
m_prg.SetRange(0,60);
SetTimer(1, 60, NULL);

return TRUE; // return TRUE unless you set the focus to a control
// EXCEPTION: OCX Property Pages should return FALSE
}

void CPrgDlg::OnTimer(UINT nIDEvent)
{
// TODO: Add your message handler code here and/or call default
m_prg.SetPos(m_prg.GetPos()+1);
UpdateData(FALSE);
CDialog::OnTimer(nIDEvent);
}

}

David Crow17-Jul-08 4:25

David Crow

17-Jul-08 4:25

ptr_Electron wrote:
But Progress dialog box is not displayed...

Have you set a breakpoint in CPrgDlg::OnInitDialog() to verify that control is reaching that method?

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ptr_Electron17-Jul-08 22:12

Re: Thread is not creating the Progress Dialog [modified]

17-Jul-08 22:12

Yes, it is working fine in the absents of while loop, but it is not reach there when place whie loop

Mark Salsbery17-Jul-08 7:38

Mark Salsbery

17-Jul-08 7:38

You should be using

CWinThread* AfxBeginThread(
   CRuntimeClass* pThreadClass,
   int nPriority = THREAD_PRIORITY_NORMAL,
   UINT nStackSize = 0,
   DWORD dwCreateFlags = 0,
   LPSECURITY_ATTRIBUTES lpSecurityAttrs = NULL 
);

instead of

pThread->CreateThread();

to create a UI thread. Otherwise, your thread won't get the
WM_MYTHREADMESSAGE you post to it.

*Edit*<br />
Actually you can leave your thread creation code the way it is as<br />
long as your ThreadPrgIndiaction class has an InitInstance() override<br />
that returns TRUE.  That will cause the message queue to be created for <br />
the thread.<br />

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

modified on Thursday, July 17, 2008 3:19 PM

ptr_Electron17-Jul-08 18:19

17-Jul-08 18:19

But the above code is working fine, with out the while loop. The problem, progress bar indication is shown on the dialog, when while loop is placed.

aks.17-Jul-08 20:56

aks.

17-Jul-08 20:56

The problem is that the ui thread is creating a window that is a child of a main thread window . Windows communicate with their parent window, so the ui thread has to wait until the parent window's thread processes a message. I think thats y ur CPrgDlg is not displayed. It may display after completing the loop.
I think u can create a worker thread and can call CPrgDlg from the thread function.

aks

ptr_Electron18-Jul-08 0:11

Programmatic Function Profiling

18-Jul-08 0:11

did that, but no luck.

Varghese Paul M17-Jul-08 1:51

Varghese Paul M

17-Jul-08 1:51

Hi All,
Is there a way to find out the time taken by a function to complete (in terms of nanoseconds) in my c++ code without using "Function Profiling" feature of the linker. I tried GetTickCount(), but it gives the time in milliseconds. It always returns 0 because my function completes its task less than in one millisecond.

Thanks in advance

CPallini17-Jul-08 2:03

17-Jul-08 2:03

You may use the

QueryPerformanceFrequency [<a href="http://msdn.microsoft.com/en-us/library/ms644905.aspx" target="_blank" title="New Window">^</a>], QueryPerformanceCounter

[^] pair.

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Cedric Moonen17-Jul-08 2:18

Cedric Moonen

17-Jul-08 2:18

This can only be applied if there's thread switching: you are measuring the time before the function and then after the function and assume that the difference is the time spent in the function. While this might seem correct, it's not always the case: the scheduler can decide in the middle of your function to switch to another thread, which will 'pause' your function for a certain amount of time. Thus you will take that time into account also, which is wrong.
A better approach would be to measure the time really spent for this thread. But unfortunately, I don't know how to do this (but I guess it is possible).

Cédric Moonen
Software developer

Charting control [v1.4]
OpenGL game tutorial in C++

CPallini17-Jul-08 2:41

17-Jul-08 2:41

I knew that. I provided only a way to measure time on a smaller scale.
Smile | :)

Cedric Moonen17-Jul-08 2:45

Cedric Moonen

17-Jul-08 2:45

CPallini wrote:
I knew that.

Yeah I guess so. I was mainly clarifying for the OP Smile | :)

Cédric Moonen
Software developer

Charting control [v1.4]
OpenGL game tutorial in C++

CPallini17-Jul-08 3:01

17-Jul-08 3:01

Well, indeed your was a good point against profiling-do-it-yourself.
The OP should also be aware that between milli and nano there are micro seconds (i.e. pretending nano seconds accuracy it is at present, a bit Utopian!)
Smile | :)

Rajesh R Subramanian17-Jul-08 2:46

Rajesh R Subramanian

17-Jul-08 2:46

I agree with you. There can be several downsides to any and every method that can be suggested here, but there's no single fool proof way of doing it, or at least that I don't know of one. What if the method which is supposed to measure the time elapsed takes more time to execute than the actual set of instructions whose execution time is to be measured? D'Oh! | :doh:

It becomes more bizarre as we go down to get more precision.

Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.

Microsoft MVP - Visual C++[^]

CPallini17-Jul-08 2:53

17-Jul-08 2:53

Rajesh R Subramanian wrote:
What if the method which is supposed to measure the time elapsed takes more time to execute than the actual set of instructions whose execution time is to be measured?

A philosophical approach to quantum mechanics?
Big Grin | :-D

Rajesh R Subramanian17-Jul-08 3:01

Rajesh R Subramanian

17-Jul-08 3:01

I had to re-read my post to realise why did you make a comment like that. Laugh | :laugh:

Sometimes, the philosopher in me wakes up. $Shucks | :-\$

Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.

Microsoft MVP - Visual C++[^]

Hamid_RT17-Jul-08 2:10

Hamid_RT

17-Jul-08 2:10

Does this[^] helpful?

Rajesh R Subramanian17-Jul-08 2:43

Rajesh R Subramanian

17-Jul-08 2:43

This blog post[^] may give you some insights.

I doubt if there's a ready made API that can give results at nano second precision. RDTSC[^] can be a good thing to bet upon, but don't take my word for it. Unsure | :~

Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.

Microsoft MVP - Visual C++[^]

CPallini17-Jul-08 2:49