C语言课程设计_存储管理分区分配算法

1、C语言课程设计_存储管理分区分配算法/*pcb.c*/#include stdio.h#include stdlib.h#include string.h#define MAX 32767typedef struct node /*设置分区描述器*/ int address,size; struct node *next;RECT;/*函数原型*/RECT *assignment(RECT *head,int application);void acceptment1(RECT *head,RECT *back1);void acceptment2(RECT *head,RECT *back1

2、) ;int backcheck(RECT *head,RECT *back1);void print(RECT *head);/*变量声明*/RECT *head,*back,*assign1,*p;int application1,maxblocknum;char way;/*主函数*/main() char choose10; int check; head=malloc(sizeof(RECT); /*建立可利用区表的初始状态*/ p=malloc(sizeof(RECT); head-size=MAX; head-address=0; head-next=p; maxblocknum

3、=1; p-size=MAX; p-address=0; p-next=NULL; print(head);/*输出可利用表初始状态*/ printf(Enter the way(best or first(b/f)n);/*选择适应策略*/ scanf(%c,&way); do printf(Enter the assign or accept(as/ac)n); scanf(%s,choose); /*选择分配或回收*/ if(strcmp(choose,as)=0) /*as为分配*/ printf(Input application:n); scanf(%d,&application1

4、);/*输入申请空间大小*/ assign1=assignment(head,application1);/*调用分配函数*/ if(assign1-address=-1)/*分配不成功*/ printf(Too large application!,assign fails!nn); else printf(Success!ADDRESS=%5dn,assign1-address); /*分配成功*/ print(head); /*输出*/ else if(strcmp(choose,ac)=0) /*回收*/ back=malloc(sizeof(RECT); printf(Input A

5、dress and Size!n); scanf(%d%d,&back-address,&back-size);/*输入回收地址和大小*/ check=backcheck(head,back); /*检查*/ if(check=1) if(tolower(way)=f)/*首先适应算法*/ acceptment1(head,back); /*首先适应*/ else acceptment2(head,back);/*最正确适应*/ print(head); while(!strcmp(choose,as)|!strcmp(choose,ac);/*分配函数*/RECT *assignment(R

6、ECT *head,int application) RECT *after,*before,*assign; assign=malloc(sizeof(RECT); /*分配申请空间*/ assign-size=application; assign-next=NULL; if(applicationhead-size|applicationaddress=-1; /*申请无效*/ else before=head; after=head-next; while(after-sizenext; after=after-next; if(after-size=application) /*结点

7、大小等于申请大小那么完全分配*/ if(after-size=head-size) maxblocknum-; before-next=after-next; assign-address=after-address; free(after); else if(after-size=head-size) maxblocknum-; after-size=after-size-application; /*大于申请空间那么截取相应大小分配*/ assign-address=after-address+after-size; if(tolower(way)=b)/*如果是最正确适应，将截取后剩余结

8、点重新回收到适宜位置*/ before-next=after-next; back=after; acceptment2(head,back); if(maxblocknum=0) /*修改最大数和头结点值*/ before=head; head-size=0; maxblocknum=1; while(before!=NULL) if(before-sizehead-size) head-size=before-size; maxblocknum=1; else if(before-size=head-size) maxblocknum+; before=before-next; assig

9、n1=assign; return assign1; /*返回分配给用户的地址*/void acceptment1(RECT *head,RECT *back1)/*首先适应*/ RECT *before,*after; int insert; before=head; after=head-next; insert=0; while(!insert) /*将回收区插入空闲区表*/ if(after=NULL)| (back1-addressaddress)& (back1-address=before-address) before-next=back1; back1-next=after;

10、 insert=1; else before=before-next; after=after-next; if(back1-address=before-address+before-size)/*与上一块合并*/ before-size=before-size+back1-size; before-next=back1-next; free(back1); back1=before; if(after!=NULL&(after-address=back1-address+back1-size) /*与下一块合并*/ back1-size=back1-size+after-size; bac

11、k1-next=after-next; free(after); if(head-sizesize) /*修改最大块值和最大块个数*/ head-size=back1-size; maxblocknum=1; else if(head-size=back1-size) maxblocknum+;/*最正确适应，back1为回收结点的地址*/void acceptment2(RECT *head,RECT *back1) RECT *before,*after; int insert ; insert=0; before=head; after=head-next; if(head-next=N

12、ULL) /*如果可利用区表为空*/ head-size=back1-size; head-next=back1; maxblocknum+; back1-next=NULL; else while(after!=NULL) /*与上一块合并*/ if(back1-address=after-size+after-address) before-next=after-next; back-size=after-size+back1-size; free(after); after=NULL; else after=after-next; before=before-next; before=h

13、ead; after=head-next; while(after!=NULL) if(after-address=back1-size+back1-address) /*与下一块合并*/ back1-size=back1-size+after-size; before-next=after-next; free(after); after=NULL; else before=before-next; after=after-next; before=head;/*将回收结点插入到适宜的位置*/ after=head-next; do if(after=NULL|(after-sizeback

14、1-size) before-next=back1; back1-next=after; insert=1; else before=before-next; after=after-next; while(!insert); if(head-sizesize) /*修改最大块值和最大块数*/ head-size=back1-size; maxblocknum+; else if(head-size=back1-size) maxblocknum+; void print(RECT *head) /*输出链表*/ RECT *before,*after; int index,k; before

15、=head-next; index=1; if(head-next=NULL) printf(NO part for assignment!n); else printf(*index*address*end*size*n); while(before!=NULL) printf(-n); printf( %-13d%-13d%-13d%-13dn,index,before-address,before-address+before-size-1,before-size); printf(-n); index+; before=before-next; /*检查回收块的合法性，back1为要回收的结点地址*/int backcheck(RECT *head,RECT *back1) RECT *before,*after; int check=1; if(back1-addresssizenext; while(before!=NULL)&check)/*地址