操作系統(tǒng)存儲器管理——最佳適應(yīng)算法

1、存儲管理上機(jī)作業(yè) 存儲管理上機(jī)作業(yè)——最佳適應(yīng)算法 最佳適應(yīng)算法以最佳適應(yīng)為例，給出可變式分區(qū)的分配回收算法。 以最佳適應(yīng)為例，給出可變式分區(qū)的分配回收算法。源程序如下： 源程序如下：#include #include#define #define N 5struct struct freearea freearea{int int startaddress; startaddress;int int size; size;int in

2、t state; state;}freeblock[N]={{20,20,1},{80,30,1},{160,10,1},{200,40,0},{250,50,1}}; }freeblock[N]={{20,20,1},{80,30,1},{160,10,1},{200,40,0},{250,50,1}};int int allocate( allocate(int int applyarea) applyarea){int int i

3、,tag=0; i,tag=0;for for(i=0;iapplyarea freeblock[i].startaddress=freeblock[i].startaddress+applyarea;freeblock[i].size=freeblock[i].size-applyarea; freeblock[i].size=freeblock[i].size-applyarea;tag=1; tag=1;// //有滿足條件的分區(qū)

4、時， 有滿足條件的分區(qū)時，tag tag置1return return freeblock[i].startaddress-applyarea; freeblock[i].startaddress-applyarea;}else else if if(freeblock[i].size==applyarea freeblock[i].state=0;tag=1; tag=1;// //有滿足條件的分區(qū)時， 有滿足條件的分區(qū)時，tag t

5、ag置1return return freeblock[i].startaddress; freeblock[i].startaddress;}}if if(tag==0) (tag==0)return return -1; -1;}void void set_free() set_free(){int int i,j,s,l,tag1=0,tag2=0,tag3=0; i,j,s,l,tag1=0,tag2=0,tag3=0;prin

6、tf( printf(“please “please input input the the start start address address you you want want to to set set free:\n“ free:\n“); );scanf( scanf(“%d“ “%d“, ,printf( printf(“please “please input input the the size:\n“ size:\

7、n“); );scanf( scanf(“%d“ “%d“, ,{freeblock[j].startaddress=s; freeblock[j].startaddress=s;freeblock[j].size=l; freeblock[j].size=l;freeblock[j].state=1; freeblock[j].state=1;break break;}}}}}}void void adjust() adjust(){

8、int int i,j; i,j;struct struct freearea freearea temp; temp;for for(i=0;ifreeblock[j].size) (freeblock[i].size>freeblock[j].size){temp.size=freeblock[i].size; temp.size=freeblock[i].size;temp.startaddress=freeblock[i]

9、.startaddress; temp.startaddress=freeblock[i].startaddress;temp.state=freeblock[i].state; temp.state=freeblock[i].state;freeblock[i].size=freeblock[j].size; freeblock[i].size=freeblock[j].size;freeblock[i].startaddress=f

10、reeblock[j].startaddress; freeblock[i].startaddress=freeblock[j].startaddress;freeblock[i].state=freeblock[j].state; freeblock[i].state=freeblock[j].state;freeblock[j].size=temp.size; freeblock[j].size=temp.size;freebloc

11、k[j].startaddress=temp.startaddress; freeblock[j].startaddress=temp.startaddress;freeblock[j].state=temp.state; freeblock[j].state=temp.state;}}}for for(i=0;i<N;i++) (i=0;i<N;i++){if if(freeblock[i].state==0 temp.s

12、ize=freeblock[i].size;temp.startaddress=freeblock[i].startaddress; temp.startaddress=freeblock[i].startaddress;temp.state=freeblock[i].state; temp.state=freeblock[i].state;freeblock[i].size=freeblock[i+1].size; freeblock

13、[i].size=freeblock[i+1].size;freeblock[i].startaddress=freeblock[i+1].startaddress; freeblock[i].startaddress=freeblock[i+1].startaddress;freeblock[i].state=freeblock[i+1].state; freeblock[i].state=freeblock[i+1].state;f