Re: MFC and threads

From:
"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp>
Newsgroups:
microsoft.public.vc.mfc
Date:
Tue, 03 Apr 2007 11:26:27 -0400
Message-ID:
<eP3ZrRgdHHA.4656@TK2MSFTNGP06.phx.gbl>
one-trick-pony wrote:

Greetings,

I am running into a problem when trying to pause a thread in MFC based
application. This is my first time using user defined Events for
synchronization. The scenario is like this. Code executes in a worker
thread and based on some conditions thread launches another new dialog
window. That window displays some message to user ie, Hello There! in
an Edit control. I provide a Resume button on the bottom of that
message Window so that user can continue after reading the message and
the worker thread should continue from where it left off. This is the
code for that Resume button.

void DUMMY::OnResume()
{
    // TODO: Add your control notification handler code here
    CWorkerDlg dlg; << Primary window which launched Dummy dialog
Window
    dlg.paused = FALSE; << paused defined in CWorkerDlg as BOOL

    // sets the state of the specified event object to signaled.
    if ( ! ::SetEvent(dlg.hEvnt) )
    {
        AfxMessageBox("SetEvent not sucessful");
    }

    // User is done reading the message-Close the window
                EndDialog(0);

}

First problem, my SetEvent always reports failure. Why? Also, I get
debug asseration failure windows. When it reaches the last line,
EndDialog(0) it pops up Debug Assertion Failure window. What am I
doing wrong?


This is quite confusing. Is the dialog class DUMMY or is it CWorkerDlg?
  The failure of SetEvent and the assertion indicate that your dlg
variable is not the dialog that is being displayed.

How and where do you display the dialog? You said that "thread launches
a new dialog window" but worker threads cannot display windows.

--
Scott McPhillips [VC++ MVP]

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