Re: Critical section-Updating the Dialog from Workerthread

From:
Mikel <mikel.luri@gmail.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Fri, 30 Mar 2012 04:38:17 -0700 (PDT)
Message-ID:
<16d90ca9-b4fa-4a37-8ef0-75b9c04550d9@w5g2000yqi.googlegroups.com>
On 30 mar, 13:10, Lucress Carol <incognito...@gmx.de> wrote:

On 30 Mrz., 03:38, scott...@mvps.org wrote:

In your original post you said you wanted to compute something in the t=

hread 40 times and display the result in the GUI. So after the thread compu=
tes it should post the result in the wParam.

In your most recent post you now have the result (newvalue) shown as a =

parameter, but you still don't use it! Instead, you are setting newvalue to=
 something else, then displaying the something else. The task of the OnSend=
CalculatedValue function should be to display the newvalue that it receives=
 from the thread.

Is there a possibility to calculate in the Thread procedure the
operation rand()*m_Slider.GetPos()


Yes. Whenever the slider changes you get OnHScroll. Have the main threa=

d OnHScroll store the GetPos() value in an int variable. The thread can rea=
d the int value without synchronization.

How can the thread read that int value? should the gui post a
PostThreadMessage to the thread with the value??


How about something like this:

class CWorkerThreadMgr
{
// Your stuff

protected:
    int m_pos;

public:
    void SetPos(int pos) { m_pos = pos; }
    int GetPos() { return m_pos; }
}

void CStartCalculationDlg::OnHScroll(UINT nSBCode, UINT nPos,
CScrollBar* pScrollBar)
{
    // Whatever you have now

    m_WorkerThreadMgr.SetPos(m_Slider.GetPos());
}

static UINT WINAPI ThreadProc( LPVOID lptest )
{
    CWorkerThreadMgr* pCalculateMgr = reinterpret_cast<
CWorkerThreadMgr*>( lptest);

    for( UINT uCount = 0; uCount < 40; uCount++ ){
        int value = pCalculateMgr->rand() *pCalculateMgr.GetPos();
        PostMessage(pCalculateMgr-> m_hWnd, WM_SENDCALCULATED_VALUE,
value, 0);
    }
}

LRESULT CStartCalculationDlg::OnSendCalculatedValue( WPARAM v,
LPARAM )
{
      m_Calculation.Format(_T("%d"), (int)v);
      SetDlgItemText(IDC_CALCULATION, m_Calculation);

      return 1;
}

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