quick and dirty CPU usage counter

Question

I'd like to track how much CPU power (ie. cycles) my (multi-threaded) program is consuming over some period of time. I know this information is available without too much overhead because the windows task manager displays it (in the form of a percentage), so how can I get access to that information? I'm not interested in profiling, because I want the compiled release build to display this information.

Answer 1

I'd say the Performance counters are the right thing for you. You are basically able to get the same information the Taskmanager offers you. Check out the Pdh* API functions using the PDH.DLL.

Here a few more infos / examples:

http://www.drdobbs.com/windows/win32-performance-measurement-options/184416651

http://www.codeproject.com/Articles/377/CPdh-v1-03-NT-Performance-Info

http://www.codeproject.com/Articles/58240/Performance-Counters-Enumerator

Answer 2

Try

QueryPerformanceCounter  

QueryPerformanceFrequency

LARGE_INTEGER Start;
LARGE_INTEGER Stop;
LARGE_INTEGER Freq;
void PerformanceStart()
{
QueryPerformanceFrequency(&Freq);
// Set a processor affinity mask for the specified thread in multicore systems
 DWORD_PTR curThreadMask=SetThreadAffinityMask(GetCurrentThread(),0x1);
QueryPerformanceCounter(&Start);
// Restore a processor affinity mask
SetThreadAffinityMask(GetCurrentThread(),curThreadMask);
}

double PerformanceStop()
{
DWORD_PTR curThreadMask=SetThreadAffinityMask(::GetCurrentThread(),0x1);
QueryPerformanceCounter(&Stop);      
SetThreadAffinityMask(GetCurrentThread(),curThreadMask);
double Time=static_cast<double>(Stop.QuadPart-Start.QuadPart);
double Freqency=(double)m_liFreq.QuadPart/1000000.0;
double Elapsed = Time/Freqency;
// in microseconds
return Elapsed;
}

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Thanks, Renjith V R

Answer 3

If you are looking to get a CPU percentage of a particular thread (or set of threads), you probably want GetThreadTimes.