操作系统时间片论转调度算法.doc

实验报告（一）1.程序代码：#include#include#define N 2 /定义时间片typedef struct nodechar name10;int cputime;int needtime;char state; /W for wait,R for run,F for finishstruct node *next;PCB;int n; /进程总数void show(PCB *pcb,PCB *pcb_rear) /显示某一队列中进程状况PCB *p_show;p_show=pcb;while(p_show != pcb_rear)printf( %s %d %d %c n,p_show-name,p_show-cputime,p_show-needtime,p_show-state);p_show=p_show-next;printf( %s %d %d %c n,p_show-name,p_show-cputime,p_show-needtime,p_show-state);void main()PCB *wait,*w_rear,*run,*r_rear,*finish,*f_rear; /三个队列的首尾 wait=NULL; w_rear=NULL; run=NULL; r_rear=NULL; finish=NULL; f_rear=NULL;/输入进程信息printf(输入进程数:); scanf(%d,&n);for(int i=1;iname);printf(输入进程所需cpu时间:);scanf(%d,&p-needtime);p-cputime=0;p-state=W;p-next=NULL;if(i=1)wait=p;w_rear=wait;elsew_rear-next=p;w_rear=w_rear-next; /输出输入的进程信息printf(进程名 占用CPU时间 还需CPU时间 进程状态n);show(wait,w_rear);/第一批进程调入run队列/第一个进程进入run=wait;wait=wait-next;run-next=NULL;r_rear=run;r_rear-state=R;/剩下的进程进入for(int i1=1;i1next=wait; r_rear=r_rear-next; wait=wait-next; r_rear-state=R; r_rear-next=run;elseprintf(已无就绪进程); break;printf(进程名 占用CPU时间 还需CPU时间 进程状态n);if(run!=NULL)show(run,r_rear);if(wait!=NULL)show(wait,w_rear);if(finish!=NULL)show(finish,f_rear); printf(*开始执行*n); /执行时间片while(run != NULL) if(run-needtime0) run-cputime+; run-needtime-; run=run-next; r_rear=r_rear-next; else /有进程执行完run-state=F;/进程从run调出到finish,并从wait中调入一个进程/调出if(finish=NULL) /若finish为空/finish=run;f_rear=finish;run=run-next;r_rear-next=run;f_rear-next=NULL;elsef_rear-next=run;f_rear=f_rear-next;run=run-next;r_rear-next=run;f_rear-next=NULL; /调入if(wait!=NULL) r_rear-next=wait; r_rear=r_rear-next; wait=wait-next; r_rear-state=R; r_rear-next=run; else printf(：已无就绪进程n); if(r_rear=r_rear-next & r_rear-needtime=0)f_rear-next=run; f_rear=f_rear-next;f_rear-next=NULL;f_rear-state=F;run=NULL;r_rear=NULL; printf(进程名 占用CPU时间 还需CPU时间 进程状态n); if(run!=NULL) show(run,r_rear);if(wa