操作系统实验报告-时间片调度轮转算法

操作系统实验报告第一次实验——时间片调度轮转算法实验时间：2014.11.7院系：计算机科学与技术学院班级：软件2班实验要求：实验选题：时间片调度轮转算法程序流程图及程序代码开始流程图开始确定时间片大小确定时间片大小就绪队列为空 空则等待就绪队列为空 进行下一 否选择队首进程进行执行一个时间片次选择队首进程进行执行一个时间片执行该进程运行完成 该进程运行完成 否 送到就绪队列末尾送到就绪队列末尾 是 程序代码:#include<stdio.h>#include<conio.h>#defineN20typedefstructpcb{ charpname[N]; intruntime; intarrivetime; charstate; structpcb*next;}PCB;PCBhead_input;PCBhead_run;PCB*pcb_input;staticcharR='r',C='c';unsignedlongcurrent;voidinputprocess();intreadyprocess();intreadydata();intrunprocess();FILE*f;intreadyprocess(){ while(1) { if(readydata()==0) return1; else runprocess(); }}intreadydata(){ if(head_input.next==NULL) { if(head_run.next==NULL) return0; else return1; } PCB*p1,*p2,*p3; p1=head_run.next; p2=&head_run; while(p1!=NULL) { p2=p1; p1=p2->next; } p1=p2; p3=head_input.next; p2=&head_input; while(p3!=NULL) { if(((unsignedlong)p3->arrivetime<=current)&&(p3->state==R)) { printf("时间片为%8d(时间%4d);进程%s开始,\n",current,(current+500)/1000,p3->pname); fprintf(f,"时间片为%8d(时间%4d);进程%s开始,\n",current,(current+500)/1000,p3->pname); p2->next=p3->next; p3->next=p1->next; p1->next=p3; p3=p2; } p3=p3; p3=p3->next; } return1;}intrunprocess(){ PCB*p1,*p2; if(head_run.next==NULL) { current++; return1; } else { p1=head_run.next; p2=&head_run; while(p1!=NULL) { p1->runtime--; current++; if(p1->runtime<=0) { printf("时间片为%8d时间%4d进程%s结束.\n",current,(current+500)/1000,p1->pname); fprintf(f,"时间片为%8d时间%4d进程%s结束.\n",current,(current+500)/1000,p1->pname); p1->state=C; p2->next=p1->next; deletep1; p1=NULL; } else { p2=p1; p1=p2->next; } } return1; }}voidinputprocess(){ PCB*p1,*p2; intnum; unsignedlongmax=0; printf("请输入进程的数量:"); fprintf(f,"请输入进程的数量:"); scanf("%d",&num); fprintf(f,"%d\n",&num); p1=&head_input; p2=p1; p1->next=newPCB; p1=p1->next; for(inti=0;i<num;i++) { printf("请输入第%d个进程的进程名:",i+1); fprintf(f,"请输入第%d个进程的进程名:",i+1); scanf("%s",p1->pname); fprintf(f,"%s\n",p1->pname); printf("它的运行时间为:"); fprintf(f,"它的运行时间为:"); scanf("%d",&(p1->runtime)); fprintf(f,"%d\n",&(p1->runtime)); printf("它的到达时间为:"); fprintf(f,"它的到达时间为:"); scanf("%d",&(p1->arrivetime)); fprintf(f,"%d\n",&(p1->arrivetime)); p1->runtime=(p1->runtime)*1000; p1->arrivetime=(p1->arrivetime)*1000; p1->state=R; if((unsignedlong)(p1->arrivetime)>max) max=p1->arrivetime; p1->next=newPCB; p2=p1; p1=p1->next; } deletep1; p1=NULL; p2->next=NULL;}voidmain(){ f=fopen("result.txt","w"); printf("时间1=1000时间片\n"); fprintf(f,"\ntime1=1000timeslice\n"); current=0; inputprocess(); readyprocess(); getch(); fclose(f);}PCB数据结构typedefstructpcb{ charpname[