#pragma comment(lib, "pdh.lib")

#include <windows.h>
#include <pdh.h>
#include <pdhmsg.h>
#include <iostream>

using namespace std;

class CpuUsage
{
private:
        PDH_HQUERY              m_hQuery;
        PDH_HCOUNTER    m_hCounter;

public:
        CpuUsage()      :       m_hQuery( 0 ), m_hCounter( 0 )  {}
        ~CpuUsage()             {       destroy();      }

        bool    init()
        {
                PDH_STATUS      status = PdhOpenQuery (0, 0, &m_hQuery);

                if( status != ERROR_SUCCESS )
                        return false;

                status = PdhAddCounter( m_hQuery, "\Processor(_TOTAL)\% Processor Time", 0, &m_hCounter );

                if( status != ERROR_SUCCESS )
                        return false;

                status = PdhCollectQueryData( m_hQuery );

                if( status != ERROR_SUCCESS )
                {
                        return false;
                }

                return true;
        }

        void    destroy()
        {
                if( m_hQuery )
                        PdhCloseQuery( m_hQuery );
                m_hQuery = 0;
        }

        bool    getCpuUsage( double * val )
        {
                PDH_STATUS      status = PdhCollectQueryData( m_hQuery );

                if( status != ERROR_SUCCESS )
                        return false;

                PDH_FMT_COUNTERVALUE    value;

                status = PdhGetFormattedCounterValue( m_hCounter, PDH_FMT_DOUBLE,       0, &value);

                if (status != ERROR_SUCCESS)
                        return false;
                *val = value.doubleValue;
                return true;
        }

};


int main( int argc, char * argv[] )
{
        CpuUsage        cpuUsage;
        if( cpuUsage.init() == false )
                return 1;

        while( true )
        {
                double  val = 0.0;
                if( cpuUsage.getCpuUsage( &val ) )
                        cout << "CPU Usage : " << val << "%\n";
                Sleep( 500 );
        }
        cout << "\t\thttp://fehead.tistory.com\n";

        return 0;
}