CreateThread

I do not understand why my program blocks when processing a long routine eventhough I use CreateThread...any clue??

m_hThread = CreateThread( 0,
0,
ThreadFunc,
(LPVOID)Param,
0,
&m_dwThreadID);

The ThreadFunc is accessed but my dialog remains blocked until the end of the process...

Without seeing your full code me may won't find the problem. But use code tags when posting code!

This is practically the whole thing I do to call this thread...from the main thread I call this funcion (funcA). Then I pass some parameters using Param.

Code:

---

HANDLE ThreadClass::funcA(BYTE node, WORD time)
{
  DWORD Param;
  Param =(6<<24)|(node<<16)|(time);

  m_hThread = CreateThread (0,
                          0,
                          ThreadFunc,
                          (LPVOID)Param,
                          0,
                          &m_dwThreadID);

  if(!m_hThread)
  {
      // Could not create thread               
      return false;
  }
  return m_hThread;             
}


DWORD WINAPI ThreadClass::ThreadFunc(LPVOID pvParam)
{               
        BYTE func_nr = ((DWORD)pvParam>>24)&0xFF;
        ThreadEventFlag = TRUE;
        MathClass calc;               

        switch((BYTE)func_nr)
        {
          case 0:
...continue...

---

The calling code of where you call funcA might be more interesting. To see what happens after the thread was created.

Code Tags... :thumb:

here it goes

Code:

---

...
case ID_TH_SCAN_INJ:
{
  ThreadClass thread;
  int node = GetDlgItemInt(hDlg, IDC_COMBO_ELMB, NULL, NULL);
  int time = GetDlgItemInt(hDlg, IDC_TH_SCAN_TIME, NULL, NULL); // in milliseconds
                                               
  if(!thread.funcA(node, time))
      MessageBox(NULL, "Thread Error (thread.funcA)", "WRONG PARAMETER", MB_ICONEXCLAMATION | MB_OK);

  return TRUE;
}
break;
...

---

I have found that the problem comes out when I use this code (see below) inside my ThreadFunc.
g_hElmbDialog = handle of the dialog I call the thread.
If intead of calling CreateDialog using g_hElmbDialog, I use NULL, it works!!
boh??

Code:

---

g_hWaitBox = CreateDialog(GetModuleHandle(NULL), MAKEINTRESOURCE(IDD_WAITBOX), g_hElmbDialog, (DLGPROC)About);
if(g_hWaitBox != NULL)
  ShowWindow(g_hWaitBox, SW_SHOW);
else
  MessageBox(g_hElmbDialog, "CreateDialog Returned NULL", "Warning!", MB_OK | MB_ICONINFORMATION);

---

Do you know why??

Quote:

---

Originally Posted by rafraf

I have found that the problem comes out when I use this code (see below) inside my ThreadFunc.
g_hElmbDialog = handle of the dialog I call the thread.
If intead of calling CreateDialog using g_hElmbDialog, I use NULL, it works!!
boh??

Code:

---

g_hWaitBox = CreateDialog(GetModuleHandle(NULL), MAKEINTRESOURCE(IDD_WAITBOX), g_hElmbDialog, (DLGPROC)About);
if(g_hWaitBox != NULL)
  ShowWindow(g_hWaitBox, SW_SHOW);
else
  MessageBox(g_hElmbDialog, "CreateDialog Returned NULL", "Warning!", MB_OK | MB_ICONINFORMATION);

---

Do you know why??

---

Because if you show a dialog which is the child of another the parent window get's disabled until the child window has finished. This is the same behaviour as you would display a modal dialog > even if you are in another thread the parent window get's blocked until the child window gets closed.

You see why posting full code? ;)

Yes...That the parent window gets disabled I knew but that it gets blocked is something new for me... :eek:

Thanks for your help!!! :wave:

Quote:

---

Originally Posted by rafraf

Yes...That the parent window gets disabled I knew but that it gets blocked is something new for me... :eek:

Thanks for your help!!! :wave:

---

You are welcome!