C / C++ / MFC

wings2 wrote:

From what I understand, this timer should trigger every 1 ms.

wings2 wrote:

I created a timer that looks like:

m_UpdateTimer = SetTimer (1, 1, NULL);

From what I understand, this timer should trigger every 1 ms.

Nemanja Trifunovic wrote:

No way Windows can deliver that frequency. SetTimer works reasonably well for ranges over half a second, not milliseconds.

Force Code wrote:

Try it out for yourself. Set an interval of 10 (milliseconds) and every WM_TIMER msg, OutputDebugString(GetCurrentTime()). The millisecond output will increment by 10 for at least fifty iterations before being off by one.

Force Code wrote:

Try it out for yourself. Set an interval of 10 (milliseconds) and every WM_TIMER msg, OutputDebugString(GetCurrentTime()). The millisecond output will increment by 10 for at least fifty iterations before being off by one.

Force Code wrote:

Try it out for yourself. Set an interval of 10 (milliseconds) and every WM_TIMER msg, OutputDebugString(GetCurrentTime()). The millisecond output will increment by 10 for at least fifty iterations before being off by one.

Mark Salsbery wrote:

ummm - are they using the same clock? I think you'd need to compare the values against a real-time clock.

Mark Salsbery wrote:

Some possibly interesting articles...
Time is the Simplest thing...[^]
Precision is not the same as accuracy[^]

Force Code wrote:

I just tried it with QueryPerformanceCounter. It showed the WM_TIMER msgs were only off by an average of .0032%.

krishnakumar75 wrote:

I used _CRTDBG_MAP_ALLOC and _CrtMemState() to set set points in various location of application and compared to find the leak. Sometime it alerts for memory leaks and sometimes not.

#ifdef _DEBUG
class _MemStateCheck
{
public:
   CMemoryState oldMemState, newMemState, diffMemState;
 
   _MemStateCheck();
   ~_MemStateCheck();
};

_MemStateCheck::_MemStateCheck()
{
   oldMemState.Checkpoint();
}
 
_MemStateCheck::~_MemStateCheck()
{
    newMemState.Checkpoint();
    if( diffMemState.Difference( oldMemState, newMemState ) )
    {
        TRACE( "************************\n" );
        TRACE( "Memory leaks Detected\n" );
        TRACE( "************************\n" );
        diffMemState.DumpStatistics();
        diffMemState.DumpAllObjectsSince();
    }
    else
    {
        TRACE( "************************\n" );
        TRACE( "No memory leaks Detected\n" );
        TRACE( "************************\n" );
    }
}
 
_MemStateCheck MemCheckObj;
#endif  //#ifdef _DEBUG

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

// Allocate 128 bytes
//void *p = malloc(128);
void *p = _malloc_dbg(128, _NORMAL_BLOCK, __FILE__, __LINE__ );