计算机操作系统内存分配实验源代码.docx

1、计算机操作系统内存分配实验源代码#include#include#define OK 1 /完成#define ERROR 0 /出错typedef int Status;typedef struct free_table/定义一个空闲区说明表结构 int num; /分区序号 long address; /起始地址 long length; /分区大小 int state; /分区状态ElemType;typedef struct Node/ 线性表的双向链表存储结构 ElemType data; struct Node *prior; /前趋指针 struct Node *next; /后

2、继指针Node,*LinkList; LinkList first; /头结点LinkList end; /尾结点int flag;/记录要删除的分区序号Status Initblock/开创带头结点的内存空间链表 first=mallocsizeof; end=mallocsizeof; 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; return OK;vo

3、id sort/分区序号重新排序 Node *p=first-next,*q; q=p-next; fornext fornext;q;q=q-next ifdata.num=q-data.num q-data.num+=1; /显示主存分配情况void show 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; printf; printf; printf; while printfdata.num,p-data.address

4、,p-data.length; ifdata.state=0 printf; else printf; p=p-next; printf;/首次适应算法Status First_fit /为申请作业开辟新空间且初始化 Node *p=first-next; LinkList temp=mallocsizeof; temp-data.length=request; temp-data.state=1; p-data.num=1; while ifdata.state=0&data.length=request /有大小恰好合适的空闲块 p-data.state=1; return OK; bre

5、ak; else ifdata.state=0 & data.lengthrequest /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-data.length; p-data.length-=request; p-data.num+=1; return OK; break; p=p-ne

6、xt; return ERROR;/最佳适应算法Status Best_fit int ch; /记录最小剩余空间 Node *p=first; Node *q=NULL; /记录最佳插入位置 LinkList temp=mallocsizeof; temp-data.length=request; temp-data.state=1; p-data.num=1; while /初始化最小空间和最佳位置 ifdata.state=0 & data.length=request if q=p; ch=p-data.length-request; else ifdata.length p-data

7、.length q=p; ch=p-data.length-request; p=p-next; if return ERROR;/没有找到空闲块 else ifdata.length=request q-data.state=1; return OK; else temp-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; q-data.address+=request; q-data.length=ch

8、; q-data.num+=1; return OK; return OK;/最差适应算法Status Worst_fit int ch; /记录最大剩余空间 Node *p=first-next; Node *q=NULL; /记录最佳插入位置 LinkList temp=mallocsizeof; temp-data.length=request; temp-data.state=1; p-data.num=1; while /初始化最大空间和最佳位置 ifdata.state=0 & data.length=request if q=p; ch=p-data.length-request

9、; else ifdata.length data.length q=p; ch=p-data.length-request; p=p-next; if return ERROR;/没有找到空闲块 else ifdata.length=request q-data.length=1; return OK; else temp-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; q-data.address+

10、=request; q-data.length=ch; q-data.num+=1; return OK; return OK;/分配主存Status allocation int request;/申请内存大小 printf请输入申请分配的主存大小:; scanf; ifrequest printf; return ERROR; switch case 1: /默认首次适应算法 ifFirst_fit=OK printf; else printf; return OK; break; case 2: /选择最佳适应算法 ifBest_fit=OK printf; else printf; r

11、eturn OK; break; case 3: /选择最差适应算法 ifWorst_fit=OK printf; else printf; return OK; break; Status deal1/处理回收空间 Node *q=first; fornext if ifprior-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-prior; q-data.state=0; q-data.num=flag-1

12、; ifprior-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; ifprior-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-prior; q-data.state=0;

13、q-data.num=flag-1; ifprior-data.state!=0&q-next-data.state!=0 q-data.state=0; return OK;Status deal2/处理回收空间 Node *q=first; fornext if ifprior-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-data.num=flag-1;

14、 ifprior-data.state!=0&q-next-data.state=0 q-data.state=0; ifprior-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-prior; q-data.state=0; q-data.num=flag-1; ifprior-data.state!=0&q-next-data.state!=0 q-data.state=0; return OK;/主存回收S

15、tatus recovery Node *p=first; fornext ifdata.num=flag ifprior=first ifnext!=end/当前P指向的下一个不是最后一个时 ifnext-data.state=0 /与后面的空闲块相连 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; else p-data.state=0; ifnext=end/当前P指向的下一个是最后一个时 p-data.state=0;

16、 /结束ifprior=block_first的情况 else ifprior!=first ifnext!=end deal1; else deal2; /结束ifprior!=block_first的情况 /结束ifdata.num=flag的情况 printf; return OK; /主函数void main int i; /操作选择标记 int a;/算法选择标记 printf; printf; printft首次适应算法t最佳适应算法t最差适应算法n; printf; printf; printf; scanf; whilea3 printf; scanf; switch case

17、 1:printf;break; case 2:printf;break; case 3:printf;break; Initblock; /开创空间表 while show; printf; printf; scanf; if allocation; / 分配内存 else if / 内存回收 printf; scanf; recovery; else if printf; break; /退出 else /输入操作有误 printf; continue; 八、执行结果和结果分析初始化首次适应算法：当作业1、2、3顺利分配内存空间后：回收序号2里面的内存：分配作业4：回收序号3里面的内存与上邻序号2相连了回收序号1里的内存与下邻序号2相连了继续分配会发现总是按顺序查找满足要求的第一个空闲块,一旦发现就会分配：