操作系统实验---处理机调度

1、筝波大考NINGBO UNIVERSITY实验报告实验题目姓名：学号：一课程名称：操作系统实验所在学院：信息科学与工程学院专业班级：计算机任课教师：实验项目名称处理机调度一、实验目的与要限1 、给出所选实验题目。2 、给出源程序文件名和执行程序文件名。源程序中要有详细的注释。3、给出程序中使用的数据结构和符号说明。4、给出程序的流程图。5、给出运行结果。6、总结收获体会和对题解的改进意见及见解。二、实验设备及软件：装有Linux操作系统的PC机一台、实验方法（原理、流程图）设计一个按时间片轮转法调度的算法链接指针到达时间估计运行时间进程状态如右图所示。系统设置一个队头和一再指向下一个进程。 同

2、时还1 .进程控制块内容和先来先服务调度的算法一样， 个队尾指针，分别指向队列的第一个和最后一个进程。2 .为每个进程确定一个要求运行时间和到达时间。3 .按进程到达的先后次序排成一个循环队列。4 .处理机调度时，开始选择队首第一个进程运行，另外 设一个当前运行进程指针，指向当前正运行的进程。5 .本实验是模拟，所选进程并不实际运行，只是执行： 估计运行时间减1和输出当前运行进程名。应判断该进程的剩余运行时间是否为 为完成状态，并撤出就绪队列。7 .若就绪队列不空，重复上述8 .程序中应有显示和打印语句,6 .进程运行一次后，应将当前运行进程指针下移一个位置,0。若不为0,则等待下一轮调度；若

3、为 0,则则状态改5, 6步。显示每次选中进程名字和队列变化情况。进程名链接 指针到达时间估计运行时间进程状态程序流程图如下：四、实验过程、步骤及内容在下述三种调度算法中选择一题进行编程实验:1 .设计一个按先来先服务调度的算法；2 .设计一个按动态优先级调度的算法；3 .设计一个按时间片轮转法调度的算法； 本次实验选择按时间片轮转法调度的算法： 时间片轮转算法参考代码：#define N 20#include <stdio.h>#include <stdlib.h>/*#include<conio.h>*/typedef struct pcb/*进程控制块

4、定义*/ char pnameN;int runtime;int arrivetime;char state;struct pcb *next; PCB;PCB head_input; /就绪队列头指针PCB head_run; /运行队列头指针 static char R='r' ,C='c'unsigned long current; /记录系统当前时间 void inputprocess(); /* 建立进程函数 */ int readyprocess(); /*建立就绪队列函数*/ int readydata(); /*判断进程是否就绪函数 */ int

5、 runprocess(); /* 运行进程函数 */ int readyprocess() while (1) if (readydata()=0) return 1; elserunprocess();int readydata() /判断就绪队列是否为空 PCB *p1,*p2,*p3;if (head_input.next=NULL) if (head_run.next=NULL)return 0;else return 1;p1 = head_run.next;p2 = &head_run;while (p1 != NULL) p2 = pl；pl = p2->next

6、;pl = p2;p3 = head_input.next;p2 = &head_input;while (p3 != NULL) if ( ( unsigned long )p3->arrivetime <= current) && (p3->state = R) printf( "Time slice is %8ld( time %4ld); Process %s start.n" current, (current+500)/1000, p3->pname);p2->next = p3->next;p3-&g

7、t;next = p1->next;p1->next = p3;pl = p3；p3 = p2;p2 = p3;p3 = p3->next;return 1;int runprocess() PCB *p1,*p2;if (head_run.next = NULL) current+;return 1; else pl = head_run.next;p2 = &head_run;while (p1 != NULL) p1->runtime-; /时间片大小为1 current+;if (p1->runtime <= 0) printf( "

8、;Time slice is %8ld( time %4ld); Process %s end.n" current, (current+500)/1000, p1->pname);p1->state = C;p2->next=p1->next;free(p1);p1=p2->next;else p2 = p1;pl = p2->next;return 1;void inputprocess() PCB *p1,*p2;int i,num;unsigned long max = 0;printf( "How many processes

9、do you want to run:" );scanf( "%d",&num);p2 = &head_input;for (i=0; i<num; i+) p1=(PCB*)malloc( sizeof (PCB);p2->next = p1;printf( "No.%3d process input pname:" ,i+1);scanf( "%s",p1->pname);printf("runtime:");scanf( "%d",&(p

10、1->runtime);printf("arrivetime:");scanf( "%d",&(p1->arrivetime);p1->runtime = (p1->runtime)*1000;p1->arrivetime = (p1->arrivetime)*1000;p1->state = R;if ( unsigned long )(p1->arrivetime) > max)max = p1->arrivetime;p2 = p1;p2->next = NULL;void

11、main()printf( "ntime 1 = 1000 time slice'n" );current = 0;inputprocess();readyprocess();system( "stty -echo" );getchar();system( "stty echo");五、实验数据(现象)处理分析进一步生成可执行文件时出现错误 1:nbunbu* gcc shiyanS -o shiyanfishiyanS. c:3:19: fatal error: canto *h;没有那个文件或目录 tfinclude &l

12、t;xonto'h)Aconpildtton terminated *解决办法：#include <conio.h>是一个控制输出的头文件，getch()函数不能使用, 所以去掉头文件并且修改getch()函数。具体修改部分如下图所示：void main()(printf("ritirie 1 = 1000 tine)；匚uent = 6;inputpe匚reedyprocess();systemf"stty - echo");getcharf);systenf "stty echo11);进一步生成可执行文件时出现错误 2:st)t

13、ydn8+c:94:15: warning: Lncanpdttt>l.e Implicit declar of bullkin function*naLloc* enabled by defiult pl«(PCB*)RalLoc(slz«of(PCB)j解决办法：malloc的功能与头文件#include <stdlib.h>有关，但是本参考代码没有 给出头文件，所以添加头文件以后 malloc的功能可以实现了。*shiyanBx x#defln& N 2。#tnclude«stdio*#lnclude<stdlit>.h

14、>/*#include<conto|*h>+/ .* JJk T-p-a H-all I * I I h i生成可执行文件并运行：nbunbu:$ gcc &hlyan9.c -o sht/anS nbugnbu./shtyanStime 1 = 1000 time sliceHow Eny processes do you want to rur:|进行第一次测试:time 1 = 1000 time sliceHow many processes do you want to run;5inputpname:adNo. 1 process runtime:3 at

15、vettme:5No.2 processinputpname:bbruntime:4 arrlvettme:7 Mo. 3 process runtime:5 arrtvettme:9 No. A processinputinput7+已停止 nbunbu:$ ./shtyanfipnameiccpname:AZ./shtyanStime 1 = 1000 time sliceHow many processes do you wantto run:5No. 1 process runtime:? arrtvettme:©inputpname:aaMo.2 processinputp

16、name:bbruntine;3 arrlvettne:2 No. 3 process runtine:4 arrtvettme:5 No. 4 process runtime:5 arrtvettne:9 No. 5 process runtime:5 arrtvettme:12inputinputinputpname:ccpname:ddpname:eeTime slice is Time slice is0( 2600(tine time0)；2)；Process aa start.Process aa end.Time slice is2000(time2)；Process bb st

17、art.Time slice is5600(time5)；Process bb end.Time slice is5600(time5)；Process cc start.Time slice is9000(tine9)；Process cc end.Time slice is9600(time9)；Process dd start.Time slice is12000(time12)；Process ee start.Time slice is15999(time16)；Process dd end.Time slice is19000(time19)；Process ee end.进行第二

18、次测试:nbugnbu:./shtyanBtine 11G0O time sliceHow many processes do you wantto run:4No. 1 process runtime:2 arrtvettmezO No. 2 process runtine;3 arri.vetime:2 No. 3 process runtine:4 arrivetime:5 No. 4 process runtime:9 arrivetvFie:9inputinputInputInputpnaneibbphane:ccpnanezddTimesliceis0(time0);Process

19、aastart .Tinesliceis2000(time2)；Processaaend.Tinesliceis2000(time2)；Processbbstart,Timesliceis5000(tine5）；Processbbend.Tinesliceis5000(time5)；Processccstart .TimesliceIs9060(timeD；Processccend.Tinesliceis9000(tine9)；Processddstart.Ttnesliceis18000(time18)；Processddend.进行第三次测试:tine 1 = 1000 time slic

20、eHow many process.es do you wantto run:4Mo 1 process runtime:12 arrtvettme:0 M。* 2 process ruintine: 9 arrivettme:l Mq* 3 process runtime：45 arrivetime:5inputinputtnputNo.pnane:aapnane;bbpnaneiccTimesliceis0(time0)；ProcessamstartTiresliceis1000(timeProcessbbstartTimeslicets5060(time5)；ProcessccstartTineslicets25999(time26)；Pro