Windows下精确获取程序运行时间

 

#include <windows.h>
#include <iostream>
using namespace std;


class CGetPeriodTime
...{
private:
    union UTIME
    ...{
       LARGE_INTEGER _li;
       unsigned long long  _time;
    };
    class InitFreQueuency
    ...{
       public:
           unsigned long long s_Frequency;
           InitFreQueuency();
    };
    static InitFreQueuency s_InitFreQueuency; 
    UTIME _PeriodTime;

public:
    void Begin()...{QueryPerformanceCounter(&_PeriodTime._li);}
    unsigned long long End();
};

CGetPeriodTime::InitFreQueuency CGetPeriodTime::s_InitFreQueuency;

inline CGetPeriodTime::InitFreQueuency::InitFreQueuency()
...{
    UTIME li;
    QueryPerformanceFrequency(&li._li);
    s_Frequency=li._time;
}

unsigned long long  CGetPeriodTime::End()
...{
    UTIME li;
    QueryPerformanceCounter(&li._li);
    _PeriodTime._time=li._time-_PeriodTime._time;
    return (_PeriodTime._time*1000)/s_InitFreQueuency.s_Frequency;
}

int main()
...{
    CGetPeriodTime time;
    time.Begin();
    Sleep(1000);
    cout<<time.End()<<endl;
    return 0;

}