完成LRU页面调度算法的模拟

1.上代码

2.实现思路

1.上代码

#include<iostream>
using namespace std;
//内存块类
class memory
{
public:void init();void alter(int a, int b);int check_full();int check_old();int check_exist(int a);void run();void refresh();friend int manage(memory *My_Memory, int ans, int a);friend void show(memory *My_Memory, int ans);
private:int page;int time;
};
//为了多次初始化
void memory::init()
{page = 0;time = 0;
}
//修改内存块保存的页和时间
void memory::alter(int a, int b)
{page = a;time = b;
}
//检查该块是否已被占用
int memory::check_full()
{if (page == 0 && time == 0){return 1;}else{return 0;}
}
//检查该块的驻留时间
int memory::check_old()
{return time;
}
//检查该块中是否保存了页a
int memory::check_exist(int a)
{if (page == a){return 1;}else{return 0;}
}
//时间++
void memory::run()
{if (page != 0){time++;}
}
//时间置0
void memory::refresh()
{time = 0;
}
//调度作业
int manage(memory *My_Memory, int ans, int a)
{//检查内存块是否已经保存了页面afor (int i = 0; i < ans; i++){if (My_Memory[i].check_exist(a)){cout << "不发生中断，页面" << a << "已在内存块" << i << "中" << endl;My_Memory[i].refresh();return 1;}}//检查内存块是否有空闲页面for (int i = 0; i < ans; i++){if (My_Memory[i].check_full()){cout << "发生中断，" << "内存块" << i << "空闲中，页面" << a << "装入" << endl;My_Memory[i].alter(a, 0);return 0;}}//找到驻留时间最大的块，进行替换int max_time = 0;int num = -1;for (int i = 0; i < ans; i++){if (My_Memory[i].check_old()>max_time){max_time = My_Memory[i].check_old();num = i;}}cout << "发生中断，" << "内存块" << num << "中页面" << My_Memory[num].page << "被替换，页面" << a << "装入" << endl;My_Memory[num].alter(a, 0);return 0;
}
//显示内存块当前状态
void show(memory *My_Memory, int ans)
{cout << "...................................." << endl;cout << "内存块号";for (int i = 0; i < ans; i++){cout << "  |" << i;}cout << "\n页面号  ";for (int i = 0; i < ans; i++){cout << "  |" << My_Memory[i].page;}cout << "\n驻留时间";for (int i = 0; i < ans; i++){cout << "  |" << My_Memory[i].time;}cout << "\n....................................\n" << endl;
}
int main()
{cout << "***************************" << endl;cout << "***   页面置换算法LRU   ***" << endl;cout << "*** 1.设置存储区块数    ***" << endl;cout << "*** 2.页面调度模拟      ***" << endl;cout << "*** 3.缺页率统计        ***" << endl;cout << "*** 4.退出模拟器        ***" << endl;cout << "***************************" << endl;int ans, aans = 0, nohit = 0;memory My_Memory[100];int flag;while (true){cout << "\n请选择功能：";cin >> flag;if (flag == 1){//设置存储区块数cout << "请输入存储区块数：";cin >> ans;for (int i = 0; i < ans; i++){My_Memory[i].init();  }nohit = 0;aans = 0;}else if (flag == 2){//页面调度模拟while (true){for (int i = 0; i < ans; i++){My_Memory[i].run();}cout << "请输入要调入的页面(输入0结束)：";int a;cin >> a;if (a == 0){break;}aans++;if (!manage(My_Memory, ans, a)){nohit++;}show(My_Memory, ans);}}else if (flag == 3){//缺页率统计cout << "*****************" << endl;cout << "调度作业 " << aans << "次\n中断     " << nohit << "次\n缺页率   " << double(nohit) / aans * 100.00 << "%" << endl;cout << "*****************" << endl;}else if (flag == 4){//退出cout << "成功退出！\n" << endl;break;}}return 0;
}

运行ok的放心 =w=