处理器调度之动态优先数调度算法

1、1处理机调度1.1实验内容及要求实验内容：按优先数调度算法实现处理器调度。实验要求：能接受键盘输入的进程数、进程标识、进程优先数及要求运行时间，能显示每次进程调度的情况：运行进程、就绪进程和就绪进程的排列情况。1.2实验目的本实验模拟在单处理器环境下的处理器调度，加深了解处理器调度工作。1.3实验环境本实验的设计基于Windows7操作系统DevC+5.11环境，用C语言实现编程。1.4实验思路每个进程用一个PCB来代表。PCB的结构为：进程名作为进程标识。优先数赋予进程的优先数，调度时总是选取优先数大的进程先执行。要求运行时间假设进程需要运行的单位时间数。状态假设两种状态：就绪和结束，用R表

2、示就绪，用E表示结束。初始状态都为就绪状态。指针按优先数的大小把5个进程连成队列，用指针指出下一个进程PCB的首地址。开始运行之前，为每个进程确定它的“优先数”和“要求运行时间”。通过键盘输入这些参数。处理器总是选择队首进程运行。采用动态改变优先数的办法，进程每运行1次，优先数减1，要求运行时间减1。进程运行一次后，若要求运行时间不等于0，则将它加入就绪队列，否则，将状态改为“结束”，退出就绪队列。若就绪队列为空，结束，否则转到(3)重复。1.5数据结构与全局变量typedefstructpcbintpname;/进程名intpriority;/优先级intrunTime;/所需时间intst

3、ate;/状态struetpcb*next;/下一个进程控制块PCB;/进程控制块intnum;/存储进程数PCBreadyHead;/头结点，不存储进程PCB*readyEnd;/指向尾结点的指针1.6函数说明主函数main()输入进程数并调createProcess()初始化进程；若有进程，则依次调用sortProcess()、runProcess()、printProcessLink()和printProcesslnfo()。进程创建函数createProcess()输入进程标识、优先级和运行时间进行初始化。进程排序函数sortProcess()用冒泡排序算法根据进程的优先级进行降序排序

4、，每次排序之后优先级最高的进程放在就绪队列首。进程运行函数runProcess()将数组首的进程优先级和所需时间减1；若剩余所需时间为0则PCB状态标记为E(结束)。输出函数printProcessLink()和printProcessInfo()printProcessLink()输出进程链，printProcessInfo()输出进程控制块详细信息。1.7运行结果表1.1进程数5序号优先级运行时间134252341415523对表1.1数据的运行结果：il2222NO.1InputInputHO.3InputInputprocessinfornationbeforerunning：NAME

5、processinfornationbeforerunning：NAMEprocessinfornationbeforerunning：NAME444readyreadyreadyreadyreadyreadyreadyreadyreadyreadyreadyreadyreadyready4processlink：2-3-1-5-44processlink：2-1-5-4processname:1ppiority：3FunTime：4processname:2priority：5FunTime：2processname:3priority：4punTime：1processname:4prio

6、riti/：lrunTime：5processname:5priority：2runTime：3Houmanyprocessdoyouuanttorun:5InputPRIORITVRUNTIMESTATUSNEXTPRIORITYRUNTIMESTATUSNEXTPRIORITVRUNTIMESTATUSNEXT4processlink：13-2-1-5-4(Processrun:33isterminatedprocesspun:22isterminatedxhjcxhxjocxjocxhjcxhjc王111扌守尢7tr?i周底畀_辛主iC*聊!?卜干里i周hjcxhjoocxjocxjoc

7、xhjcxhxk2processinfornationbeforerunning：NAMEPRIORITYRUNTIMESTATUSNEXT241ready1134ready5523ready4415readyprocesslink：2-1-5-4processrun:2isterminatedprocessinformationbeforerunning：NAMEPRIORITYRUNTIMESTATUSNEXT134ready5523ready4415readyprocesslink：l-5-4processpun:1NAMEPRIORITYRUNTIMESTATUS523ready123

8、ready415readyprocesslink：5-1-4processpun:infornationbeforerunning：processNEXT14processNAMEinfornationbeforerunning：PRIORITYRUNTIMESTATUSNEXTreadyreadyreadyprocessl-4-5link：process1run:processinformationbeforerunning：NAMEPRIORITYRUNTIMESTATUSNEXT1processlink：4-5-1readyreadyreadyprocesspun:44Processex

9、itedaftei*25.2?secondswithyetuynvalue0niUlOAWBIBB-n|xprocessinformationbeforerunning：NAMEPRIORITYRUNTIMESTATUSNEXTprocessl-4-5link：process1run:processinformationreadyreadyready45beforerunning：processinformationbeforerunning：NAMEPRIORITVRUNTIME8THTU8NEXT404ready5501ready1101ready5-1processrun:4proces

10、sinformationbeforerunningNAMEPRIORITYRUNTIMESTATUSNEXT501ready1101ready44-13ready1-4processrun:55isterminatedNAMEPRIORITYRUNTIMESTATUSNEXT14processlink：l-4processrun:11isterminated0-1readyready4processinformationbeforerunning：NAMEPRIORITYRUNTIMESTATUSNEXT4processlink：4processrun:ready1.8实验心得指针操作是真的烦

11、。1.9实验代码#include#include#include#include#defineN32voidcreateProcess();voidsortProcess();voidprintProcessLink();voidprintProcessInfo();voidrunProcess();typedefstructpcbcharpnameN;进程名intpriority;/进程优先级intrunTime;/进程还需运行的时间片charstate;/R代表ready,E代表endstructpcb*next;PCB;intnum;/进程数PCBreadyHead;/头结点，不存储进程

12、PCB*readyEnd;/尾结点指针intmain()j/*X1111A-g-*-I-J#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*1-，|printf(*实习1-1按优先级调度算法实现处理器调度*n)；.jX1111A-g-*-I-J#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J

13、*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*#J*1-pname)；printf(%sisrunning.n,readyHead.next-pname)；printf(%sendsafter%dslice(s).,readyHead.next-pname,readyHead.next-runTime)；elsewhile(readyHead.next!=NULL)sortProce

14、ss()；printProcessInfo()；printProcessLink()；runProcess()；return0；voidcreateProcess()PCB*p,*prior；printf(Howmanyprocessdoyouwanttorun:)；scanf(%d,&num)；while(numnext=p;for(inti=0;ipname);printf(priority:);scanf(%d,&(p-priority);printf(runTime:);scanf(%d,&(p-runTime);p-state=R;p-next=(PCB*)malloc(sizeof

15、(PCB);prior=p;p=p-next;free(p);p=NULL;prior-next=NULL;readyEnd=prior;printf(n);voidsortProcess()charnameN;inti,j,priorityNum,timeNum;PCB*p,*rear;for(p=readyHead.next;p!=NULL;p=p-next)for(rear=p-next;rear!=NULL;rear=rear-next)if(p-prioritypriority)strcpy(name,p-pname);priorityNum=p-priority;timeNum=p

16、-runTime;strcpy(p-pname,rear-pname);p-priority=rear-priority;p-runTime=rear-runTime;strcpy(rear-pname,name);rear-priority=priorityNum;rear-runTime=timeNum;voidprintProcessLink()PCB*p=readyHead.next;printf(processlink:n);while(p!=NULL)printf(%s,p-pname);p=p-next;if(p!=NULL)printf(-);printf(n);voidprintProcessInfo()PCB*p=readyHead.next;printf(processinformationbeforerunning:n);printf(=n);printf(NAMEPRIORITYRUNTIMESTATUSNEXTn);printf(=n);while(p!=NULL)printf(%-16s%-8d%-8d%-8s%sn,p-pname,p-priority,p-runTime,(p-state=R)?ready:end,