QueryPerformanceCounter failure

[cilu]

Hi,

I'm getting an error while calling QueryPerformanceCounter and I don't know why.

LARGE_INTEGER start;
BOOL bRet = QueryPerformanceCounter(&start);

ASSERT(bRet);
if(FALSE == bRet)
{
   int nError = GetLastError();
   PrintError(nError);
}

The function returns FALSE, meaning it failed, but when I call GetLastError() it returns 0, meaning ERROR_SUCCES; there was no error...

However If I do this, it works just fine:

LARGE_INTEGER* start = new LARGE_INTEGER;
BOOL bRet = QueryPerformanceCounter(start);

ASSERT(bRet);
if(FALSE == bRet)
{
   int nError = GetLastError();
   PrintError(nError);
}

delete start;

LARGE_INTEGER looks like this:

typedef union union 
{  
  struct 
  {    
     DWORD LowPart;    
     LONG HighPart;  
  };  
   LONGLONG QuadPart;
} LARGE_INTEGER, *PLARGE_INTEGER;

I'm working on WinXP, with VC6.0, SP6, and have an AthlonXP 1600+.

Why is the first code failing (with 0 returned by GetErrorSucces) and the second one is just ok?

Thanks.

[cilu]

I forgot to mention that I'm doing this in a multi-thread MDI application. I cannot post it here, it has more than 200,000 code lines and it ain't worth to isolate just that part.

I tried to create another simple (MDI) application, put there the code and it works beautiful. So, it makes me wonder even more...

[Scrambler]

cilu, are you sure that problem is in multithreading? AFAIR QueryPerformanceCounter() is thread-safe function, so may be there are another circumstances?

[cilu]

I didn't say that the problem is multi-threading, I just wanted to give as much details as possible. The code posted is taken from a member function of a CDocument derived class.

[Cariboo42]

Hi,

I'm getting an error while calling QueryPerformanceCounter and I don't know why.

LARGE_INTEGER start;
BOOL bRet = QueryPerformanceCounter(&start);

ASSERT(bRet);
if(FALSE == bRet)
{
   int nError = GetLastError();
   PrintError(nError);
}

The function returns FALSE, meaning it failed, but when I call GetLastError() it returns 0, meaning ERROR_SUCCES; there was no error...

I just had the same problem but I notice something else:
- If the variable is a member of the class: The function fails.
- If the variable is a pointer (allocated with a new): The function works.
- If the variable is local (on the stack): The function works.

So my workaround is the following:

LARGE_INTEGER start;
BOOL bRet = QueryPerformanceCounter(&start);

ASSERT(bRet);
if(FALSE == bRet)
{
   int nError = GetLastError();
   PrintError(nError);
}
else
{
   m_start = start;
}

Thanks for your post, it helps me to find a solution.

Regards.