std::chrono::时钟

 

system_clock，起点是epoch，即1970-01-01 00:00:00 UTC，其刻度是1个tick，也就是_XTIME_NSECS_PER_TICK纳秒。

 

steady_clock的刻度是1纳秒，起点并非1970-01-01 00:00:00 UTC，一般是系统启动时间。

 

high_resolution_clock是system_clock或steady_clock之一，根据情况使用。

 

// 当前时间
steady_clock::time_point tpNow = steady_clock::now();
// 小时
auto n = std::chrono::duration_cast<std::chrono::hours>(tpNow - GetLastSyncTimepoint()).count();
// 分钟
auto n = std::chrono::duration_cast<std::chrono::seconds>(tpNow - GetLastHeartbitTimepoint()).count();

 

// 跨平台时间戳工具类
#ifndef _CETimestamp_hpp_
#define _CETimestamp_hpp_

#include<chrono>
using namespace std::chrono;
class CETimestamp
{
public:
    CETimestamp()
    {
        update();
    }
    ~CETimestamp()
    {}

    void    update()
    {
        _begin = high_resolution_clock::now();
    }
    /**
    *   获取当前秒
    */
    double getElapsedSecond()
    {
        return  getElapsedTimeInMicroSec() * 0.000001;
    }
    /**
    *   获取毫秒
    */
    double getElapsedTimeInMilliSec()
    {
        return this->getElapsedTimeInMicroSec() * 0.001;
    }
    /**
    *   获取微妙
    */
    long long getElapsedTimeInMicroSec()
    {
        return duration_cast<microseconds>(high_resolution_clock::now() - _begin).count();
    }
protected:
    time_point<high_resolution_clock> _begin;
};

#endif

 

 

// win下时间戳工具类
#ifndef _CELLWINTimestamp_hpp_
#define _CELLWINTimestamp_hpp_

#include <windows.h>

class CEWINTimestamp
{
public:
    CEWINTimestamp()
    {
        QueryPerformanceFrequency(&_frequency);
        QueryPerformanceCounter(&_startCount);
    }
    ~CEWINTimestamp()
    {}

    void    update()
    {
        QueryPerformanceCounter(&_startCount);
    }
    /**
    *   获取当前秒
    */
    double getElapsedSecond()
    {
        return  getElapsedTimeInMicroSec() * 0.000001;
    }
    /**
    *   获取毫秒
    */
    double getElapsedTimeInMilliSec()
    {
        return this->getElapsedTimeInMicroSec() * 0.001;
    }
    /**
    *   获取微妙
    */
    long long getElapsedTimeInMicroSec()
    {
        LARGE_INTEGER endCount;
        QueryPerformanceCounter(&endCount);
        double  startTimeInMicroSec =   _startCount.QuadPart * (1000000.0 / _frequency.QuadPart);
        double  endTimeInMicroSec   =   endCount.QuadPart * (1000000.0 / _frequency.QuadPart);
        return  endTimeInMicroSec - startTimeInMicroSec;
    }
protected:
    LARGE_INTEGER   _frequency;
    LARGE_INTEGER   _startCount;
};

#endif