操作系統(tǒng)時間片輪轉算法與優(yōu)先級調度算法

1、#include "stdio.h"#include "stdlib.h"#include "string.h"typedef struct node char name10; /*進程標識符*/ int prio; /*進程優(yōu)先數*/ int round; /*進程時間輪轉時間片*/ int cputime; /*進程占用CPU時間*/ int needtime; /*進程到完成還要的時間*/ int count; /*計數器*/ char state; /*進程的狀態(tài)*/ struct node *next; /*鏈指針*/PCB

2、;PCB *finish,*ready,*tail,*run; /*隊列指針*/int N; /*進程數*/*將就緒隊列中的第一個進程投入運行*/firstin() run=ready; /*就緒隊列頭指針賦值給運行頭指針*/ run->state='R' /*進程狀態(tài)變?yōu)檫\行態(tài)*/ ready=ready->next; /*就緒對列頭指針后移到下一進程*/*標題輸出函數*/void prt1(char a) if(toupper(a)='P') /*優(yōu)先數法*/ printf(" name cputime needtime priorit

3、y staten"); else printf(" name cputime needtime count round staten");/*進程PCB輸出*/void prt2(char a,PCB *q) if(toupper(a)='P') /*優(yōu)先數法的輸出*/ printf(" %-10s%-10d%-10d%-10d %cn",q->name, q->cputime,q->needtime,q->prio,q->state); else/*輪轉法的輸出*/ printf(" %

4、-10s%-10d%-10d%-10d%-10d %-cn",q->name, q->cputime,q->needtime,q->count,q->round,q->state);/*輸出函數*/void prt(char algo) PCB *p; prt1(algo); /*輸出標題*/ if(run!=NULL) /*如果運行指針不空*/ prt2(algo,run); /*輸出當前正在運行的PCB*/ p=ready; /*輸出就緒隊列PCB*/ while(p!=NULL) prt2(algo,p); p=p->next; p=f

5、inish; /*輸出完成隊列的PCB*/ while(p!=NULL) prt2(algo,p); p=p->next; p=ready; printf("就緒隊列："); while(p!=NULL) printf("%st",p->name); p=p->next; printf("n");p=finish; printf("完成隊列："); while(p!=NULL) printf("%st",p->name); p=p->next; printf(&qu

6、ot;n"); getch(); /*壓任意鍵繼續(xù)*/*優(yōu)先數的插入算法*/insert1(PCB *q) PCB *p1,*s,*r; int b; s=q; /*待插入的PCB指針*/ p1=ready; /*就緒隊列頭指針*/ r=p1; /*r做p1的前驅指針*/ b=1; while(p1!=NULL)&&b) /*根據優(yōu)先數確定插入位置*/ if(p1->prio>=s->prio) r=p1; p1=p1->next; else b=0; if(r!=p1) /*如果條件成立說明插入在r與p1之間*/ r->next=s;

7、s->next=p1; else s->next=p1; /*否則插入在就緒隊列的頭*/ ready=s; /*輪轉法插入函數*/insert2(PCB *p2) tail->next=p2; /*將新的PCB插入在當前就緒隊列的尾*/ tail=p2; p2->next=NULL;/*優(yōu)先數創(chuàng)建初始PCB信息*/void create1(char alg) PCB *p; int i,time; char na10; ready=NULL; /*就緒隊列頭指針*/ finish=NULL; /*完成隊列頭指針*/ run=NULL; /*運行隊列指針*/ printf

8、("Enter name and time of processn"); /*輸入進程標識和所需時間創(chuàng)建PCB*/ for(i=1;i<=N;i+) p=malloc(sizeof(PCB); scanf("%s",na); scanf("%d",&time); strcpy(p->name,na); p->cputime=0; p->needtime=time; p->state='W' p->prio=50-time; if(ready!=NULL) /*就緒隊列不空調用

9、插入函數插入*/ insert1(p); else p->next=ready; /*創(chuàng)建就緒隊列的第一個PCB*/ ready=p; / clrscr(); system("CLS"); printf(" output of priority:n"); printf("*n"); prt(alg); /*輸出進程PCB信息*/ run=ready; /*將就緒隊列的第一個進程投入運行*/ ready=ready->next; run->state='R'/*輪轉法創(chuàng)建進程PCB*/void crea

10、te2(char alg) PCB *p; int i,time; char na10; ready=NULL; finish=NULL; run=NULL; printf("Enter name and time of round processn"); for(i=1;i<=N;i+) p=malloc(sizeof(PCB); scanf("%s",na); scanf("%d",&time); strcpy(p->name,na); p->cputime=0; p->needtime=time;

11、 p->count=0; /*計數器*/ p->state='W' p->round=2; /*時間片*/ if(ready!=NULL) insert2(p); else p->next=ready; ready=p; tail=p; /clrscr(); system("CLS"); printf(" output of roundn"); printf("*n"); prt(alg); /*輸出進程PCB信息*/ run=ready; /*將就緒隊列的第一個進程投入運行*/ ready=r

12、eady->next; run->state='R'/*優(yōu)先數調度算法*/priority(char alg) while(run!=NULL) /*當運行隊列不空時，有進程正在運行*/ run->cputime=run->cputime+1; run->needtime=run->needtime-1; run->prio=run->prio-3; /*每運行一次優(yōu)先數降低3個單位*/ if(run->needtime=0) /*如所需時間為0將其插入完成隊列*/ run->next=finish; finish=r

13、un; run->state='F' /*置狀態(tài)為完成態(tài)*/ run=NULL; /*運行隊列頭指針為空*/ if(ready!=NULL) /*如就緒隊列不空*/ firstin(); /*將就緒對列的第一個進程投入運行*/ else /*沒有運行完同時優(yōu)先數不是最大，則將其變?yōu)榫途w態(tài)插入到就緒隊列*/ if(ready!=NULL)&&(run->prio<ready->prio) run->state='W' insert1(run); firstin(); /*將就緒隊列的第一個進程投入運行*/ prt(al

14、g); /*輸出進程PCB信息*/ /*時間片輪轉法*/roundrun(char alg) while(run!=NULL) run->cputime=run->cputime+1; run->needtime=run->needtime-1; run->count=run->count+1; if(run->needtime=0)/*運行完將其變?yōu)橥瓿蓱B(tài)，插入完成隊列*/ run->next=finish; finish=run; run->state='F' run=NULL; if(ready!=NULL) firs

15、tin(); /*就緒對列不空，將第一個進程投入運行*/ else if(run->count=run->round) /*如果時間片到*/ run->count=0; /*計數器置0*/ if(ready!=NULL) /*如就緒隊列不空*/ run->state='W' /*將進程插入到就緒隊列中等待輪轉*/ insert2(run); firstin(); /*將就緒對列的第一個進程投入運行*/ prt(alg); /*輸出進程信息*/ /*主函數*/main() char algo; /*算法標記*/ /clrscr(); system("CLS"); printf("type the algorithm:P/R(priority/roundrobin)n"); scanf("%c",&algo); /*輸入字符確定算法*/