计算机操作系统内存分配实验源代码

1、#defineOK1/完成#defineERROR0/出错定义一个空闲区说明表结构typedefintStatus;typedefstructfree_tableintnum;分区序号long address; /long length; /int state; /ElemType;typedef struct Node/ElemType data;struct Node *prior; /struct Node *next; /Node,*LinkList;起始地址分区大小分区状态线性表的双向链表存储结构前趋指针后继指针LinkListfirst;/头结点LinkListend;/尾结点in

2、tflag;/记录要删除的分区序号StatusInitblock()开创带头结点的内存空间链表first=(LinkList)malloc(sizeof(Node);end=(LinkList)malloc(sizeof(Node);first->prior=NULL;first->next=end;end->prior=first;end->next=NULL;end->data.num=1;end->data.address=40;end->data.length=600;end->data.state=0;returnOK;voidsort

3、()分区序号重新排序Node*p=first->next,*q;q=p->next;for(;p!=NULL;p=p->next)for(q=p->next;q;q=q->next)if(p->data.num>=q->data.num)q->data.num+=1;/显示主存分配情况voidshow() int flag=0;/用来记录分区序号Node*p=first;p->data.num=0;p->data.address=0;p->data.length=40;p->data.state=1;sort();p

4、rintf("ntt»主存空间分配情况n");printf("*nn")；printf("分区序号t起始地址t分区大小t分区状态nn");while(p)printf("%dtt%dtt%d",p->data.num,p->data.address,p->data.length);空闲 n'n");if(p->data.state=0)printf("ttelse printf("tt已分配nn");p=p->next;prin

5、tf("*nn")；/首次适应算法StatusFirst_fit(intrequest)/为申请作业开辟新空间且初始化Node*p=first->next;LinkListtemp=(LinkList)malloc(sizeof(Node);temp->data.length=request;temp->data.state=1;p->data.num=1;while(p)if(p->data.state=0)&&(p->data.length=request)/有大小恰好合适的空闲块p->data.state=1;

6、returnOK;break;elseif(p->data.state=0)&&(p->data.length>request)/有空闲块能满足需求且有剩余temp->prior=p->prior;temp->next=p;temp->data.address=p->data.address;temp->data.num=p->data.num;p->prior->next=temp;p->prior=temp;p->data.address=temp->data.address+temp

7、->data.length;p->data.length-=request;p->data.num+=1;returnOK;break;p=p->next;returnERROR;/最佳适应算法StatusBest_fit(intrequest)intch;/记录最小剩余空间Node*p=first;Node*q=NULL;/记录最佳插入位置LinkListtemp=(LinkList)malloc(sizeof(Node);temp->data.state=1;p->data.num=1;while(p)/初始化最小空间和最佳位置if(p->data

8、.state=0)&&(p->data.length>=request)if(q=NULL)q=p；ch=p->data.length-request;elseif(q->data.length>p->data.length)q=p；ch=p->data.length-request;p=p->next;if(q=NULL)returnERROR;/没有找到空闲块elseif(q->data.length=request)q->data.state=1;returnOK;elsetemp->prior=q->

9、;prior;temp->next=q;temp->data.address=q->data.address;temp->data.num=q->data.num;q->prior->next=temp;q->prior=temp;q->data.address+=request;q->data.length=ch;q->data.num+=1;returnOK;returnOK;/最差适应算法StatusWorst_fit(intrequest)intch;/记录最大剩余空间Node*p=first->next;Node

10、*q=NULL;/记录最佳插入位置LinkListtemp=(LinkList)malloc(sizeof(Node);temp->data.length=request;temp->data.state=1;p->data.num=1;while(p)初始化最大空间和最佳位置if(p->data.state=0&&(p->data.length>=request)if(q=NULL)q=p；ch=p->data.length-request;elseif(q->data.length<p->data.length)q

11、=p；ch=p->data.length-request;p=p->next;没有找到空闲块if(q=NULL)returnERROR;/elseif(q->data.length=request)q->data.length=1;returnOK;elsetemp->prior=q->prior;temp->next=q;temp->data.address=q->data.address;temp->data.num=q->data.num;q->prior->next=temp;q->prior=temp

12、;q->data.address+=request;q->data.length=ch;q->data.num+=1;returnOK;returnOK;/分配主存Statusallocation(inta)int request;/申请内存大小printf("请输入申请分配的主存大小(单位:KB):");scanf("%d”,&request);if(request<0|request=0)printf("分配大小不合适，请重试！")；returnERROR;switch(a)case 1: /默认首次适应算法

13、分配成功!if(First_fit(request)=OK)printf("t*elseprintf("t*内存不足,分配失败!*");returnOK;break;case 2: /选择最佳适应算法if(Best_fit(request)=OK) printf("t*分配成功!*)else printf("t*内存不足,分配失败!*");returnOK;break;case 3: /选择最差适应算法分配成功!if(Worst_fit(request)=OK)printf("t*else printf("t*内存

14、不足,分配失败!*");returnOK;break;)Statusdeal1(Node*p)/处理回收空间(Node*q=first;for(;q!=NULL;q=q->next)(if(q=p)(if(q->prior->data.state=0&&q->next->data.state!=0)(q->prior->data.length+=q->data.length;q->prior->next=q->next;q->next->prior=q->prior;q=q->p

15、rior;q->data.state=0;q->data.num=flag-1;)if(q->prior->data.state!=0&&q->next->data.state=0)(q->data.length+=q->next->data.length;q->next=q->next->next;q->next->next->prior=q;q->data.state=0;q->data.num=flag;)if(q->prior->data.state=0&a

16、mp;&q->next->data.state=0)q->prior->data.length+=q->data.length;q->prior->next=q->next;q->next->prior=q->prior;q=q->prior;q->data.state=0;q->data.num=flag-1;)if(q->prior->data.state!=0&&q->next->data.state!=0)q->data.state=0;)retur

17、nOK;)Statusdeal2(Node*p)/处理回收空间Node*q=first;for(;q!=NULL;q=q->next)(if(q=p)(if(q->prior->data.state=0&&q->next->data.state!=0)(q->prior->data.length+=q->data.length;q->prior->next=q->next;q->next->prior=q->prior;q=p->prior;q->data.state=0;q->

18、;data.num=flag-1;if(q->prior->data.state!=0&&q->next->data.state=0)(q->data.state=0;if(q->prior->data.state=0&&q->next->data.state=0)(q->prior->data.length+=q->data.length;q->prior->next=q->next;q->next->prior=q->prior;q=q->pri

19、or;q->data.state=0;q->data.num=flag-1;if(q->prior->data.state!=0&&q->next->data.state!=0)q->data.state=0;returnOK;/主存回收Statusrecovery(intflag)Node*p=first;for(;p!=NULL;p=p->next)if(p->data.num=flag)if(p->prior=first)if(p->next!=end)当前P指向的下一个不是最后一个时与后面的空闲块相连if

20、(p->next->data.state=0)/p->data.length+=p->next->data.length;p->next->next->prior=p;p->next=p->next->next;p->data.state=0;p->data.num=flag;elsep->data.state=0;if(p->next=end)/当前P指向的下一个是最后一个时p->data.state=0;/结束if(p->prior=block_first)的情况elseif(p->

21、prior!=first)if(p->next!=end)deall(p)；elsedeal2(p);结束if(p->prior!=block_first)的情况结束if(p->data.num=flag)的情况printf("t*回收成功*");returnOK;/主函数voidmain()inti;/操作选择标记inta;/算法选择标记printf("*n");printf("tt用以下三种方法实现主存空间的分配n");printf("t(1)首次适应算法t(2)最佳适应算法t(3)最差适应算法n");printf(”*n")Jprintf("n");printf("请输入所使用的内存分配算法：”);scanf("%d",&a);while(a&l