操作系统页面置换算法RR

绝地灬酷狼 2022-05-11 10:04 257阅读 0赞

data4.txt输入文件内容：

5
    3
    A B C D E
    0 6 10 16 24
    15 10 12 4 8

//
    #include <iostream>
    #include <queue>
    #include <iomanip>
    #include <fstream>
    using namespace std;
     
    typedef struct  
    {
    	char name;
    	int ArrivalTime;
    	int ServiceTime;
    	int FinishedTime;
    	int WholeTime;
    	double WeightWholeTime;
    }RR;
     
    static queue<RR>RRqueue;  //声明一个队列
    static double AverageWT =0,AverageWWT=0;
    static int q;  //时间片
    static int n;  //进程个数
    static RR RRarray[100];  //进程结构
     
    void Input()
    {
    	//文件读取模式
    	ifstream inData;
    	inData.open("./data4.txt");
    	//data.txt表示q = 4的RR调度算法
    	//data2.txt表示q = 1的RR调度算法
    	inData>>n;
    	inData>>q;
     
    	for (int i=0;i<n;i++)
    	{
    		inData>>RRarray[i].name;
    	}
    	for (int i=0;i<n;i++)
    	{
    		inData>>RRarray[i].ArrivalTime;
    	}
    	for (int i=0;i<n;i++)
    	{
    		inData>>RRarray[i].ServiceTime;
    	}
     
     
    	//用户输入模式
    	//cout<<"****************************************************************"<<endl;
     
    	//cout<<"please input the number of process n = ";
    	//cin>>n;
    	//cout<<"please input the number of timeSlice q = ";
    	//cin>>q;
     
    	//cout<<"please input the name of process:"<<endl;
    	//for (int i=0;i<n;i++)
    	//{
    	//	cin>>RRarray[i].name;
    	//}
     
    	//cout<<"please input the ArrivalTime of process:"<<endl;
    	//for (int i=0;i<n;i++)
    	//{
    	//	cin>>RRarray[i].ArrivalTime;
    	//}
     
    	//cout<<"please input the ServiceTime of process:"<<endl;
    	//for (int i=0;i<n;i++)
    	//{
    	//	cin>>RRarray[i].ServiceTime;
    	//}
     
    	cout<<"****************************************************************"<<endl;
     
    	//输出用户所输入的信息
    	cout<<"The information of processes is the following:"<<endl;
    	cout<<setw(10)<<"processName"<<" ";
    	cout<<setw(10)<<"ArrivalTime"<<" ";
    	cout<<setw(10)<<"ServiceTime"<<" "<<endl;
    	for (int i=0;i<n;i++)
    	{
    		cout<<setw(10)<<RRarray[i].name<<" ";
    		cout<<setw(10)<<RRarray[i].ArrivalTime<<" ";
    		cout<<setw(10)<<RRarray[i].ServiceTime<<" "<<endl;
    	}
    	cout<<"****************************************************************"<<endl;
    }
     
    void RRAlgorithm()
    {
    	char processMoment[100];   //存储每个时间片p对应的进程名称
    	RRqueue.push(RRarray[0]);
     
    	int processMomentPoint = 0;
    	int CurrentTime=0;
    	int tempTime;   //声明此变量控制CurrentTime的累加时间，当前进程的服务时间小于时间片q的时候，起到重要作用
    	int i=1;  //指向还未处理的进程的下标
    	int finalProcessNumber = 0;   //执行RR算法后，进程的个数
    	int processTime[50];
     
    	//CurrentTime的初始化
    	if (RRarray[0].ServiceTime>=q)
    	{
    		CurrentTime = q;
    	}
    	else
    	{
    		CurrentTime = RRarray[0].ServiceTime;
    	}
     
    	while(!RRqueue.empty())
    	{	
    		for (int j=i;j<n;j++)   //使得满足进程的到达时间小于当前时间的进程都进入队列
    		{
    			if (RRarray[j].name!=NULL && CurrentTime >= RRarray[j].ArrivalTime) 
    			{
    				RRqueue.push(RRarray[j]);
    				i++;
    			}
    		}
    		if (RRqueue.front().ServiceTime<q)
    		{
    			tempTime = RRqueue.front().ServiceTime;
    		}
    		else
    		{
    			tempTime = q;
    		}
     
    		RRqueue.front().ServiceTime -= q;   //进程每执行一次，就将其服务时间 -q
     
    		//将队首进程的名称放入数组中
    		processMoment[processMomentPoint] = RRqueue.front().name;
    		processMomentPoint++;
    		processTime[finalProcessNumber] = tempTime;
    		finalProcessNumber++;
     
     
    		if (RRqueue.front().ServiceTime <= 0)  //把执行完的进程退出队列
    		{
    			//RRqueue.front().FinishedTime = CurrentTime;
    			RRqueue.pop();   //如果进程的服务时间小于等于，即该进程已经服务完了，将其退栈
     
    		}
    		else
    		{
    			//将队首移到队尾
    			RRqueue.push(RRqueue.front());
    			RRqueue.pop();
    		}
    		CurrentTime += tempTime;	
    											
    	}
     
    	//进程输出处理   每个时间段对应的执行的进程
    	cout<<"各进程的执行时刻信息："<<endl;
    	cout<<"  "<<"0时刻 --> "<<setw(2)<<processTime[0]<<"时刻";
    	processTime[finalProcessNumber]=0;
    	int time = processTime[0];
     
    	int count = 0;
     
    	for (int i=0;i<finalProcessNumber;i++)
    	{		
    		count = 0;
    		cout<<setw(3)<<processMoment[i]<<setw(3)<<endl;
     
    		while(RRarray[count].name!=processMoment[i] && count<n)
    		{
    			count++;
    		}
    		RRarray[count].FinishedTime = time;
     
    		if (i<finalProcessNumber - 1)
    		{
    			cout<<setw(3)<<time<<"时刻"<<" --> "<<setw(2)<<time + processTime[i+1]<<"时刻"<<setw(3);
    			time += processTime[i+1];		
    		}
     
    	}
    	cout<<endl;
     
    	//周转时间、带权周转时间、平均周转时间、带权平均周转时间的计算
    	//1. 周转时间 = 完成时间 - 到达时间
    	//2. 带权周转时间 = 周转时间/服务时间
     
    	for (int i=0;i<n;i++)
    	{
    		RRarray[i].WholeTime = RRarray[i].FinishedTime - RRarray[i].ArrivalTime;
    		RRarray[i].WeightWholeTime = (double)RRarray[i].WholeTime/RRarray[i].ServiceTime;
    	}
     
    	double x=0,y=0;
    	for (int i=0;i<n;i++)
    	{
    		x += RRarray[i].WholeTime;
    		y += RRarray[i].WeightWholeTime;
    	}
     
    	AverageWT = x/n;
    	AverageWWT = y/n;
     
    }
     
    void display()
    {
    	cout<<"******************************************************"<<endl;
    	cout<<"RR调度算法执行后：进程相关信息如下："<<endl;
    	cout<<setw(10)<<"进程名（ID）"<<" ";
    	cout<<setw(10)<<"到达时间"<<" ";
    	cout<<setw(10)<<"服务时间"<<" ";
    	cout<<setw(10)<<"完成时间"<<" ";
    	cout<<setw(10)<<"周转时间"<<" ";
    	cout<<setw(10)<<"带权周转时间"<<endl;
    	for (int i = 0;i<n;i++)
    	{
    		cout<<setw(10)<<RRarray[i].name<<" ";
    		cout<<setw(10)<<RRarray[i].ArrivalTime<<" ";
    		cout<<setw(10)<<RRarray[i].ServiceTime<<" ";
    		cout<<setw(10)<<RRarray[i].FinishedTime<<" ";
    		cout<<setw(10)<<RRarray[i].WholeTime<<" ";
    		cout<<setw(10)<<RRarray[i].WeightWholeTime<<" "<<endl;;
    	}
    	cout<<"所有进程的平均周转时间 = "<<AverageWT<<endl;
    	cout<<"所有进程的平均带权周转时间 = "<<AverageWWT<<endl;
    	cout<<"******************************************************"<<endl;
    }
     
    int main()
    {
    	Input();
    	RRAlgorithm();
    	display();
    	system("pause");
    	return 0;
    }

![在这里插入图片描述][70]

[70]: /images/20220511/99666a4d53aa414ca596086fe7ca9a45.png