Board index » Visual Studio » Crash bug in CDialog::DoModal

Visual Studio214
Hi all,



this is related to a post i made last week.



To summarize i have a internal network monitoring app that we're currently

adding support for ups devices. So i have a popup modal message box

(using this class from codeproject ->

www.codeproject.com/dialog/MessageBoxDialog.asp) which tells the user

they have X seconds to shut everything down or the server will do it for

them.

This has a timeout and the [OK=X] button that gets updated via OnTimer.

the server can send a "all clear" packet and in that case i want to kill the

existing messagebox, and popup a new messagebox saying "all clear" with a

10second timeout.



This mostly works, but about 1/3 of the time i get a crash in DoModal after

the 2nd dialog box hits it timeout and disappears and i get a crash in

DoModal from the FIRST dialog box which causes my app to crash.



the code is below, while tryign to debug it i have this horrible feeling

it's cause it appears runmodalloop runs in seperate thread and my thread is

trying to delete the cdialog ptr from under mfc's feet.



void CFMainUIDlg::OnReportUPSDeviceAlert( const Socket1Packet &packet)

{

BIT_ICD::STRUCT_REPORT_UPS_ALERT status;

int length = sizeof(BIT_ICD::STRUCT_REPORT_UPS_ALERT);

const char* body = packet.m_PacketBody.c_str();

memcpy( &status, body, length);



if( m_bKillMessageBox )

{

if(m_pDlgMessageBox)

{

Sleep(500);



delete m_pDlgMessageBox;

m_pDlgMessageBox = 0;

m_bKillMessageBox = false;

}

}

UI::ConnInfoIterator i = m_connections.find( status.IP );

if ( i == m_connections.end() )

return;

BIT_ICD::UPSInfo ups;

ups.eStatus = i->second->s.eUPSStatus;

strncpy( ups.IP, i->first.c_str(), i->first.length() );

strncpy( ups.sDeviceName, i->second->sPrettyName.c_str(),

i->second->sPrettyName.length() );



UpdateTreeItem( ups );



if ( !m_pDlgMessageBox )

{

if ( status.eStatus == BIT_ICD::UPS_POWER_LOSS )

{

CString upsName = i->second->sPrettyName.c_str();

CString strTitle;

strTitle.Format(UI::sUPSStatusMessagePowerLossAlertTitle.c_str(),

upsName.GetBuffer() );



CString strMessage(UI::sUPSStatusMessagePowerLossAlertMessage.c_str());

// Create a message box dialog.

m_pDlgMessageBox = new CMessageBoxDialog(this, strMessage, strTitle,

MB_OK | MB_ICONEXCLAMATION);

// Set the timeout for the message box.

m_pDlgMessageBox->SetTimeout(status.iWaitingTime, false);

// Display the dialog.

INT_PTR nresult = m_pDlgMessageBox->DoModal();

delete m_pDlgMessageBox;

m_pDlgMessageBox = NULL;

}

}

else

{

//dialog box exists, and we got an updated ups status. so we kill the box.

if( ( status.eStatus == BIT_ICD::UPS_NORMAL) || (status.eStatus ==

BIT_ICD::UPS_CHARGING ) )

{

Sleep(500);

//m_pDlgMessageBox->EndDialog( IDOK);

m_bKillMessageBox = true;

CMessageBoxDialog d(this,

UI::sUPSStatusMessagePowerRestoreMessage.c_str(),

UI::sUPSStatusMessagePowerRestoreTitle.c_str(), MB_OK |

MB_ICONEXCLAMATION );

d.SetTimeout( 10, false);

int nResult = (int) d.DoModal();

}

}

}


-

blogs.msdn.com/oldnewthing/archive/2005/02/23/378866.aspx">blogs.msdn.com/oldnewthing/archive/2005/02/23/378866.aspx

blogs.msdn.com/oldnewthing/archive/2005/03/04/385100.aspx">blogs.msdn.com/oldnewthing/archive/2005/03/04/385100.aspx



--

Sheng Jiang

Microsoft MVP in VC++

"Srivatsan Vat Raghavan" <SrivatsanVatRaghavan@discussions.microsoft.com>

wrote in message news:839D9A11-F4F4-4234-885C-D38D493AE2F1@microsoft.com...



-

hrmm.. ok. i've read that, but i'm not sure as to my proper course.

How does this work w/ DoModal?

i believe i am already using a timer attached to the cmessageboxdialog, and

it's not using any NULL hwnd's but they're all to the cMessageboxdialog,

whose parent is my dialog, which, aiui, is the proper course.



so you suggest i make a scratch window to attach the timer to? i'm not sure

i get the reasonsing for that, since there are timers already on the

cmessageboxdialog.





"Sheng Jiang[MVP]" wrote: