本文共 3686 字，大约阅读时间需要 12 分钟。

下面列出C++的代码：

1.实现StopWatch类，做测量时间用

/*filename:stopwatch.h*/#ifndef STOPWATCH_H_INCLUDED#define STOPWATCH_H_INCLUDED#include<Windows.h>class StopWatch{public: StopWatch(void); ~StopWatch(void);private: LARGE_INTEGER beginticks; LARGE_INTEGER endticks ; LARGE_INTEGER frequency;//高性能计数器的频率：每秒357,9545个tick 我的INTEL T7500 public: void Start(); void Stop(); double GetCostMillisecond(); };#endif // STOPWATCH_H_INCLUDED/****************************************filename:StopWatch.cpp*****************************************/#include "StopWatch.h"#include<iostream>using namespace std;StopWatch::StopWatch(void){ beginticks.QuadPart=0; endticks.QuadPart=0; frequency.QuadPart=0; QueryPerformanceFrequency(&frequency); }StopWatch::~StopWatch(void){}void StopWatch::Start(){ //beginticks=GetTickCount(); QueryPerformanceCounter(&beginticks); }void StopWatch::Stop(){ QueryPerformanceCounter(&endticks);}double StopWatch::GetCostMillisecond(){ unsigned long long cost=(unsigned long long)(endticks.QuadPart-beginticks.QuadPart); double millsecond=(double)cost*1000.0/(double)frequency.QuadPart; return millsecond;} 

2.实现测试工作类

//filename:WorkClass.h#ifndef WORKCLASS_H#define WORKCLASS_Hclass WorkClass{ public: WorkClass(); ~WorkClass(); double AddTest(); double FibTest(); double MulTest(); double DivTest(); protected: private: unsigned long fib(unsigned long n);};#endif //filename：WorkClass.cpp#include "../include/WorkClass.h"#include "../stopwatch.h"#include <iostream>using namespace std;WorkClass::WorkClass(){ //ctor}WorkClass::~WorkClass(){ //dtor}double WorkClass::AddTest(){ int count=10000000,i=0,j=0,count2=10; double sum=0.0; for(i=0;i<count2;i++) for(j=0;j<count;j++) sum+=j; return sum;}double WorkClass::MulTest(){ int count=10000*10000,i=0; double sum=0.0; for(i=1;i<count;i++)sum*=i; return sum;}double WorkClass::DivTest(){ int count=10000*10000,i=0; double sum=0.0; for(i=1;i<count;i++)sum/=i; return sum;}unsigned long WorkClass::fib(unsigned long n){ if (n < 2) return(1); else return(fib(n-2) + fib(n-1));}double WorkClass::FibTest(){ return (double)fib(30);} 

3.实现自动测试类，测试10次，取平均成绩

//filename:AutoTestClass.h#ifndef AUTOTESTCLASS_H#define AUTOTESTCLASS_H#include "WorkClass.h"class AutoTestClass{ public: AutoTestClass(); ~AutoTestClass(); void AutoTest(WorkClass &wc,double (WorkClass::*item)()); protected: private:};#endif // AUTOTESTCLASS_H//filename:AutoTestClass.cpp#include "../include/AutoTestClass.h"#include "../stopwatch.h"#include<iostream>using namespace std;AutoTestClass::AutoTestClass(){ //ctor}AutoTestClass::~AutoTestClass(){ //dtor}void AutoTestClass::AutoTest(WorkClass &wc,double (WorkClass::*item)()){ const int test_count=10; double test_time=0.0,ret=0.0; int run_count=0; StopWatch sw; for(run_count=0;run_count<test_count;run_count++) { ret=0.0; sw.Start(); ret=(wc.*item)(); if(ret>0)sw.Stop(); else sw.Stop(); test_time+=sw.GetCostMillisecond(); } cout<<"work cost average time(10)="<<test_time/test_count<<endl;} 

4.最后是程序入口函数

#include"include/WorkClass.h"#include"include/AutoTestClass.h"#include <iostream>using namespace std;int main(){ WorkClass work_c; AutoTestClass atc; atc.AutoTest(work_c,&WorkClass::AddTest); atc.AutoTest(work_c,&WorkClass::FibTest); atc.AutoTest(work_c,&WorkClass::MulTest); atc.AutoTest(work_c,&WorkClass::DivTest); return 0;} 

C和C++要注意VS2010的优化可能导致StopWatch取值错误。所以特别加了相关性代码，防止VS2010优化而导致的计时错误。

（这应该是VS2010优化的BUG，VS2010优化确实很厉害，可惜这点过头了。）

转载地址：http://fccpi.baihongyu.com/