C / C++ / MFC

UINT CTimer::ThreadProc( LPVOID pParam )
{
    LPTIMERDATA tData = (LPTIMERDATA)pParam;

    EnterCriticalSection( &m_csLock );

    LARGE_INTEGER  lilastTime = m_liStartTime;
    UINT_PTR       uIdEvent   = tData->uIdEvent;
    UINT           uSleepTime = tData->uSleepTime;
    HWND           hWnd       = tData->hWnd;

    LeaveCriticalSection( &m_csLock );

    LARGE_INTEGER  liCurrentTime;
    BOOL           bIsActive  = TRUE;

    do
    {
        QueryPerformanceCounter( &liCurrentTime );
        double dMilliSecs = ( (double)liCurrentTime.QuadPart - (double)lilastTime.QuadPart );
        dMilliSecs /= (double)m_liFrequency.QuadPart;
        dMilliSecs *= 1000;

        if ( (UINT)dMilliSecs % uSleepTime == 0 )
            TimerProc( hWnd, WM_TIMER, uIdEvent, GetTickCount() );

        EnterCriticalSection( &m_csLock );

        uSleepTime = tData->uSleepTime;
        bIsActive  = tData->bIsRunning;

        LeaveCriticalSection( &m_csLock );

        Sleep(0);

    } while( bIsActive );

    _endthreadex( 1 );

    return 0;
}