SendMessageTimeout, Wm_COPYDATA, interlocking

From:

mosfet <john.doe@anonymous.org>

Newsgroups:

microsoft.public.vc.mfc

Date:

Thu, 14 Jun 2007 16:35:14 +0200

Message-ID:

<46715222$0$11649$426a74cc@news.free.fr>

HI,

I am trying to port a sofwtare on pocket pc.
Here is the architecture :

I have two different processes (client/server)that communicates via a
WM_COPYDATA.
In the direction of Server->Client, SendMessage is used
In the direction of CLient->Server, SendMessageTimeout with SMTO_BLOCK
(Prevents the calling thread from processing any other requests until
the function returns)

The problem is on pocket SendMessageTimeout only have a SMTO_NORMAL
parameter. It means the calling thread is not blocked.

Here is the situation :

My server sends to my client a WM_COPYDATA via a SendMessage.

My client receives the WM_COPYDATA and during the message processing
call a method called GetInfo that send WM_COPYDATA to get information
from server.

#ifdef _WIN32_WCE
#define SM_GEN_SMTO SMTO_NORMAL
#else // _WIN32_WCE
#define SM_GEN_SMTO SMTO_BLOCK
#endif // _WIN32_WCE

CSyncCLientApi::GetInfo(..)
{
ULong_t lResult = SendMessageTimeout( m_hServer, WM_COPYDATA, 0, (
LPARAM ) &CopyData, SM_GEN_SMTO, 1500,&rcMsg );
}

BOOL CMainFrame::OnCopyData(CWnd* pWnd, COPYDATASTRUCT* pCopyDataStruct)
{
    switch( l_pSyncMessage->nState )
    {
        case SYNC1:
        GetInfo(..);
        break;

        case SYNC2:
        GetInfo(..);
        break;
    }

return CFrameWnd::OnCopyData(pWnd, pCopyDataStruct);
}

When I try to debug I put a breakpoint in the SYNC1 case and when I
pass after the SendMessageTimeout, I RE-ENTER into the GetInfo function
because of the case SYNC2.
It means that my first GetInfo always receives bad data.

I am a bit lost ...