操作系统内存分配实验代码

1、#include<stdio.h> #include<iostream.h> #include<string.h> #include<iomanip.h> const int MAXJOB=100; /定义表最大记录数 typedef struct node int start; /空闲分区的起始地址 int length; /空闲分区的长度 char tag20; /分区信息是否已分配 job; job freesMAXJOB; /定义空闲区表 int free_quantity; /空闲区的个数 job occupysMAXJOB;/定义已分

2、配区表 int occupy_quantity; /已分配区的个数 /初始化函数 void initial() int i; for(i=0;i<MAXJOB;i+) freesi.start=-1; freesi.length=0; strcpy(freesi.tag,"free"); occupysi.start=-1; occupysi.length=0; strcpy(occupysi.tag,""); free_quantity=0; occupy_quantity=0; /读数据函数 int readData() FILE *fp; c

3、har fname20; cout<<"请输入初始空闲表文件名:" cin>>fname; if(fp=fopen(fname,"r")=NULL) /读文件 cout<<"错误,文件打不开,请检查文件名"<<endl; else while(!feof(fp) /文件结束 fscanf(fp,"%d",&freesfree_quantity.start); fscanf(fp,"%d",&freesfree_quantity.le

4、ngth); free_quantity+; return 1; return 0; /sort选择排序 void sort() int i,j,p; for(i=0;i<free_quantity-1;i+) p=i; for(j=i+1;j<free_quantity;j+)/空闲分区按地址递增的顺序排列 if(freesj.start<freesp.start) p=j; if(p!=i) freesfree_quantity=freesi; freesi=freesp; freesp=freesfree_quantity; /显示函数 void view() int

5、i; cout<<endl<<"-"<<endl; cout<<"当前空闲表:"<<endl; cout<<"起始地址 长度 状态"<<endl; for(i=0;i<free_quantity;i+) cout.setf(2); cout.width(12); cout<<freesi.start; cout.width(10); cout<<freesi.length; cout.width(8); cout<&

6、lt;freesi.tag<<endl; cout<<endl<<"-"<<endl; cout<<"当前已分配表:"<<endl; cout<<"起始地址 长度 占用作业名"<<endl; for(i=0;i<occupy_quantity;i+) cout.setf(2); cout.width(12); cout<<occupysi.start; cout.width(10); cout<<occupys

7、i.length; cout.width(8); cout<<occupysi.tag<<endl; /最先适应分配算法 void earliest() /空闲分区按地址递增的顺序排列 char job_name20; int job_length; int i,j,flag,t; cout<<"请输入新申请内存空间的作业名和空间大小:" cin>>job_name; /输入作业的名称 cin>>job_length; /输入作业的长度 flag=0; /分配成功与否信号 for(i=0;i<free_qua

8、ntity;i+) if(freesi.length>=job_length) flag=1; /可以分配 if(flag=0) cout<<endl<<"Sorry,当前没有能满足你申请长度的空闲内存,请稍候再试"<<endl; else t=0; i=0; while(t=0) if(freesi.length>=job_length) /从空闲分区 表顺序查找，直到找到第一能满足其大小要求的空闲分区为止 t=1; i+; i-; occupysoccupy_quantity.start=freesi.start; /修改

9、已分区的相关信息 strcpy(occupysoccupy_quantity.tag,job_name); occupysoccupy_quantity.length=job_length; occupy_quantity+; if(freesi.length>job_length) freesi.start+=job_length; freesi.length-=job_length; else /刚好分配则空闲分区数减一 for(j=i;j<free_quantity-1;j+) freesj=freesj+1; free_quantity-; cout<<&quo

10、t;内存空间成功"<<endl; /最优适应分配算法 void excellent() /空闲分区按大小递增的顺序排列 char job_name20; int job_length; int i,j,flag,t; cout<<"请输入新申请内存空间的作业名和空间大小:" cin>>job_name; cin>>job_length; flag=0; for(i=0;i<free_quantity;i+) if(freesi.length>=job_length) flag=1; if(flag=0)

11、cout<<endl<<"Sorry,当前没有能满足你申请长度的空闲内存,请稍候再试"<<endl; else t=0; i=0; while(t=0) if(freesi.length>=job_length) t=1; i+; i-; for(j=0;j<free_quantity;j+) if(freesj.length>=job_length)&&(freesj.length<freesi.length) i=j; occupysoccupy_quantity.start=freesi.st

12、art; strcpy(occupysoccupy_quantity.tag,job_name); occupysoccupy_quantity.length=job_length; occupy_quantity+; if(freesi.length>job_length) freesi.start+=job_length; freesi.length-=job_length; else for(j=i;j<free_quantity-1;j+) freesj=freesj+1; free_quantity-; cout<<"内存空间成功"<

13、<endl; /最坏适应算法 void worst() /空闲分区按大小递减的顺序排列 char job_name20; int job_length; int i,j,flag,t; cout<<"请输入新申请内存空间的作业名和空间大小:" cin>>job_name; cin>>job_length; flag=0; for(i=0;i<free_quantity;i+) if(freesi.length>=job_length) flag=1; if(flag=0) cout<<endl<<

14、"Sorry,当前没有能满足你申请长度的空闲内存,请稍候再试"<<endl; else t=0; i=0; while(t=0) if(freesi.length>=job_length) t=1; i+; i-; for(j=0;j<free_quantity;j+) if(freesj.length>=job_length)&&(freesj.length>freesi.length) i=j; occupysoccupy_quantity.start=freesi.start; strcpy(occupysoccup

15、y_quantity.tag,job_name); occupysoccupy_quantity.length=job_length; occupy_quantity+; if(freesi.length>job_length) freesi.start+=job_length; freesi.length-=job_length; else for(j=i;j<free_quantity-1;j+) freesj=freesj+1; free_quantity-; cout<<"内存空间成功"<<endl; /撤消作业 void fin

16、ished() char job_name20; int i,j,flag,p=0; int start; int length; cout<<"请输入要撤消的作业名:" cin>>job_name; flag=-1; for(i=0;i<occupy_quantity;i+) if(!strcmp(occ upysi.tag,job_name) flag=i; start=occupysi.start; length=occupysi.length; if(flag=-1) cout<<"没有这个作业名"<

17、;<endl; else /加入空闲表 for(i=0;i<free_quantity;i+) if(freesi.start+freesi.length)=start)/上空 if(i+1)<free_quantity)&&(freesi+1.start=start+length) /上空且下空，不为最后一个 freesi.length=freesi.length+freesi+1.length+length; for(j=i+1;j<free_quantity;j+) freesj=freesj+1; free_quantity-; p=1; els

18、e freesi.length+=length; /上空且下不空 p=1; if(freesi.start=(start+length) /下空 freesi.start=start; freesi.length+=length; p=1; /空闲中没有 if(p=0) freesfree_quantity.start=start; freesfree_quantity.length=length; free_quantity+; /删除分配表中的该作业 for(i=flag;i<occupy_quantity;i+) occupysi=occupysi+1; occupy_quanti

19、ty-; /显示学生信息函数 void version() cout<<endl<<endl; cout<<" 主存储器空间的分配与回收模拟系统"<<endl; cout<<endl<<endl; void main() int flag=0; int t=1; int chioce=0; version(); initial(); flag=readData(); while(flag=1) sort(); cout<<endl<<endl<<"="