VC中监测程序运行时间（二）-毫秒级

/*
*    微秒级计时器，用来统计程序运行时间 
*   http://blog.csdn.net/hoya5121/article/details/3778487#comments
*   //整理 [10/16/2013 Duan Yihao]
*/

#pragma once

#include "stdafx.h"


//////////////////////////////////////////////////////////////////////////
class timer  
{
public:
    timer();
    ~timer();

    void start(void);

    void end(void);   

    DWORD getTime(void) const;

private:
    LARGE_INTEGER m_i64CPUFreq; 
    LARGE_INTEGER m_i64Begin;
    LARGE_INTEGER m_i64End;
    void reset(void);
};


//////////////////////////////////////////////////////////////////////////
timer::timer()
{
    QueryPerformanceFrequency(&m_i64CPUFreq);
}

timer::~timer()
{

}

void timer::start(void)
{
    reset();
    QueryPerformanceCounter(&m_i64Begin);
}

void timer::end(void)
{
    QueryPerformanceCounter(&m_i64End);
}

DWORD timer::getTime(void) const
{
    DWORD dwTotalMicrosecond = 0;
    LARGE_INTEGER i64TickCount;
    i64TickCount.QuadPart = m_i64End.QuadPart - m_i64Begin.QuadPart;
    dwTotalMicrosecond = (DWORD) (i64TickCount.QuadPart * 1000000 / m_i64CPUFreq.QuadPart);

    return dwTotalMicrosecond;
}

void timer::reset(void)
{
    m_i64Begin = m_i64End;
}


/*
//////////////////////////////////////////////////////////////////////////
//MFC下使用举例：

void CtestMFCView::OnTest()
{

    // TODO: 在此添加命令处理程序代码
    //测试例子

    //计时开始
    timer t;
    t.start();

    //运算过程

        for(int i = 0; i < 10; i++)
        {
            int n = i;
            for(int i = 0; i < 10000; i++)
            {
                int n = i;
            }
        }

    //计时结束
    t.end();

    //输出运行时间
    CString s;
    s.Format(_T("%u ms"), t.getTime());
    AfxMessageBox(s);
}

*/