Question

I have a function triggered by a message(WM_ONDATA defined by me) the function will execute this code :

MSG msg;
while(::PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) 
{

    if( !AfxGetApp()->PumpMessage() )
    { 
        ::PostQuitMessage(0); 
        return 0; 
    } 
}
return 1;

The problem is that there could be on the message queue another message that could trigger the function.

I’m wondering if I can make it process all the message but WM_ONDATA?

Answer 1

You could get the window proc to ignore the message or to queue it’s execution. If you’re just looking to avoid recursion, have a reentrance lock

 class MyDlg : ...
 {
       MyDlg(...) : m_inOnData(false), ... { .... }

       ...
     private:
        BOOL m_inOnData;
 };

….

 void MyDlg::OnOnData(...)
 {
      if (m_inOnData)
          return;
      m_inOnData = TRUE;
      ....

      m_inOnData = FALSE;
 }

You could get fancy with a scoped RIIA struct (so things will be exception safe and slightly less verbose)