可變分區(qū)存儲管理方式的內(nèi)存分配和回收

1、#include<stdio.h>/定義輸入/輸出函數(shù)#include<iostream.h>/數(shù)據(jù)流輸入/輸出 #include<string.h>/字符串處理#include<iomanip.h>/參數(shù)化輸入/輸出const int MJ=10;/假定系統(tǒng)允許的最大作業(yè)數(shù)量為10typedef struct nodeint address;int length;char tag10;job;job freesMJ;int free_quantity;job occupysMJ;int occupy_quantity;int read()FIL

2、E *fp;char fn10;cout<<"請輸入初始空閑表文件名:"cin>>fn;if(fp=fopen(fn,"r")=NULL) 其意義是在當前目錄下打開文件file a，只允許進行“讀”操作，并使fp指向該文件cout<<"錯誤,文件打不開,請檢查文件名"<<endl;elsewhile(!feof(fp)fscanf(fp,"%d,%d",&freesfree_quantity.address,&freesfree_quantity.le

3、ngth);free_quantity+; fscanf(文件指針，格式字符串，輸入表列)；return 1;return 0;void sort()int i,j,p;for(i=0;i<free_quantity-1;i+)p=i;for(j=i+1;j<free_quantity;j+)if(freesj.address<freesp.address)p=j;if(p!=i)freesfree_quantity=freesi;freesi=freesp;freesp=freesfree_quantity;void view()int i;cout<<endl

4、<<"mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm"<<endl;cout<<"輸出空閑區(qū)表：n起始地址 分區(qū)長度 狀態(tài)n"<<endl;for(i=0;i<free_quantity;i+)cout.setf(2);cout.width(12);cout<<freesi.address;cout.width(10);cout<<freesi.length;cout.width(8);cout<&l

5、t;freesi.tag<<endl;cout<<endl<<"wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww"<<endl;cout<<"輸出已分分區(qū)表：n起始地址 分區(qū)長度 占用作業(yè)名n"<<endl;for(i=0;i<occupy_quantity;i+)cout.setf(2);cout.width(12);cout<<occupysi.address;cout.width(10);

6、cout<<occupysi.length;cout.width(8);cout<<occupysi.tag<<endl;void ear()char job_name10;int job_length;int i,j,flag,t;cout<<"請輸入分配內(nèi)存的作業(yè)名和空間大小:"cin>>job_name;cin>>job_length;flag=0;for(i=0;i<free_quantity;i+) /尋找空間大于作業(yè)的空閑區(qū)登記項if(freesi.length>=job_len

7、gth)flag=1;if(flag=0) /未找到空閑區(qū)，返回cout<<endl<<"無可用的空閑區(qū)n"<<endl;elset=0;i=0;while(t=0)if(freesi.length>=job_length)/找到可用空閑區(qū)，開始分配t=1;i+;i-;occupysoccupy_quantity.address=freesi.address; /修改已分配區(qū)表 strcpy(occupysoccupy_quantity.tag,job_name);occupysoccupy_quantity.length=job_

8、length;occupy_quantity+;if(freesi.length>job_length)freesi.address+=job_length;freesi.length-=job_length;elsefor(j=i;j<free_quantity-1;j+)freesj=freesj+1;free_quantity-;cout<<"內(nèi)存空間成功:)"<<endl; void reclaim()/回收作業(yè)所占的內(nèi)存空間char job_name20;int i,j,flag,p=0;int address;int leng

9、th;/尋找已分分區(qū)表中對應(yīng)的登記項cout<<"輸入要回收分區(qū)的作業(yè)名:"cin>>job_name;flag=-1;for(i=0;i<occupy_quantity;i+)if(!strcmp(occupysi.tag,job_name)flag=i;address=occupysi.address;length=occupysi.length;if(flag=-1) /在已分分區(qū)表中找不到作業(yè)cout<<"沒有這個作業(yè)名"<<endl;else/修改空閑區(qū)表，加入空閑表for(i=0;i<

10、;free_quantity;i+)if(freesi.address+freesi.length)=address)if(i+1)<free_quantity)&&(freesi+1.address=address+length)freesi.length=freesi.length+freesi+1.length+length;for(j=i+1;j<free_quantity;j+)freesj=freesj+1;free_quantity-;p=1;elsefreesi.length+=length;p=1;if(freesi.address=(addres

11、s+length)freesi.address=address;freesi.length+=length;p=1;if(p=0)freesfree_quantity.address=address;freesfree_quantity.length=length;free_quantity+;/刪除分配表中的該作業(yè)for(i=flag;i<occupy_quantity;i+)occupysi=occupysi+1;occupy_quantity-;void main()int flag=0;int t=1;int chioce=0;int i;for(i=0;i<MJ;i+)f

12、reesi.address=-1;/空閑區(qū)表初始化freesi.length=0;strcpy(freesi.tag,"free");occupysi.address=-1;/已分分區(qū)表初始化occupysi.length=0;strcpy(occupysi.tag,"");free_quantity=0;occupy_quantity=0;flag=read();while(flag=1)sort();cout<<"選擇功能項: （0-退出，1-分配內(nèi)存，2-回收內(nèi)存，3-顯示內(nèi)存）n"<<endl;cout<<&