操作系统实习

1、南京林业大学南方学院 计算机科学与技术 n120801107 操作系统期末实习院系：南方学院专业：计算机科学与技术班级：n1208011姓名：李晓雨学号：n120801107 实验1 进程管理1. 实验目的· 加深对进程概念的理解，明确进程和程序的区别。· 进一步认识并发执行的实质。· 分析进程争用资源的现象，学习解决进程互斥的方法。· 了解Linux系统中进程通信的基本原理。 2. 实验预备内容（1）阅读Linux的sched.h 源码文件，加深对进程管理概念的理解。（2）阅读Linux的fork.c源码文件，分析进程的创建过程。3. 实验内容 （1）

2、进程的创建 （2）编写一段程序，使用系统调用fork（）创建两个子进程。当此程序运行时，在系统中有一个父进程和两个子进程活动。让没一个进程在屏幕上显示一个字符：父进程显示字符“a”；子进程分别显示字符“b”和字符“c”。试观察记录屏幕上的显示结果，并分析原因。4. 实验程序 #include<stdio.h>Main()int p1,p2;while(p1=fork()= -1);if(p1=0)putchar(b)elsewhile(p2=fork()= -1);if(p2=0)putchar(c);else putchar(a); putchar(n);5.实验结果程序运行后出

3、现bac、bca、abc等多种情况。实验2 进程间通信一、实验目的Linux系统的进程通信机构（IPC）允许在任意进程间大批量地交换数据。本实验的目的是了解和熟悉Linux支持的消息通信机制、共享存储区机制及信息机制。二、实验预备内容阅读Linux系统的msg.csem.c等源码文件，熟悉Linux的三种通信机制。三、实验内容（1）消息的创建，发送和接收。1.使用系统调用msgget( ),msgsnd( ),msgrev( )j及msgctl( )编制一长度1k的消息的发送和接收程序。2.观察上面程序，说明控制消息队列系统msgctl（）在此起什么作用？3. 实验程序#include<

4、stdio.h>#include<stdlib.h>#include<sys/types.h>#include<sys/msg.h>#include<sys/ipc.h>#define MSGKEY 75struct msgform long mytype; char mtext1030;msg;int msgqid,i;void CLENT()int i; msgqid=msgget(MSGKEY,0777);for(i=10;i>=1;i- -) msg.mytype=i; printf(“(client)sentn”);msgs

5、nd(msgqid,&msg,1024,0); /*发送消息msg入msgqid消息队列*/exit(0);void SERVER()msgqid=msgget(MSGKEY,0777LIPC_CREAT); /*由关键字获得消息队列*/ do msgrcv(msgqid,&msg,1030,0,0); /*从msgqid队列接受消息msg*/printf(“(server)receivedn”);while(msg.mytype!=1);msgctl(msgqid,IPC-RMID,0); /*消息队列为1时释放队列*/Exit(0);void main() while(i=

6、fork()=-1);if(!i)SERVER();while(i=fork()=-1;if(!i)CLIENT();wait(0);wait(0);4、实验结果：useruser-desktop:$ gcc -0 shiyan2 shiyan2.cuseruser-desktop:$ ./shiyan2(client)sent(client)sent(client)sent(server)received(server)received(server)received(client)sent(client)sent(server)received(client)sent(server)rec

7、eived(client)sent(server)received(client)sent(server)received(client)sent(server)received(client)sent(server)received(server)receiveduseruser-desktop:$实验3 存储管理1.实验目的： 存储管理的主要功能之一是合理地分配空间。请求页式管理式一种常用的虚拟存储管理技术。 本实验的目的是通过请求页式存储管理中页面置换算法模拟设计，了解虚拟存储技术的特点，掌握请求页式存储管理的页面置换算法。2.实验内容：(1)通过随机数产生一个指令序列，共320条指令。

8、指令的地址按下述原则生成：150的指令是顺序执行的；225的指令是均匀分布在前地址部分；325的指令是均匀分布在后地址部分。3实验程序#include <stdio.h>#define TRUE 1#define FALSE 0#define INVALID -1#define NULL 0#define total_instruction 320#define total_vp 32#define clear_period 50typedef struct int pn,pfn,counter,time;pl_type;pl_type pltotal_vp;struct pfc_

9、struct *next;typedef struct pfc_struct pfc_type;Pfc_type pfctotal_vp,*freepf_head,*busypf_head,*busypf_tail;int disaffect,atotal_instruction,offsettotal_instruction;int total_pf;void initialize(total_pf)int i;disaffect=0;for(i=0;i<total_vp;i+) pli.pn=I;pli.pfn=INVALID;pli.counter=0;pli.time=-1;fo

10、r(i=1;i<total_pf;i+) pfci-1.next=&pfci;Pfci-1.pfn=i-1;pfctotal_pf-1.next=NULL;pfctotal_pf-1.pfn=total_pf-1;freepf_head=&pfc0;void FIFO(total_pf)int total_pf; int I,j;pfc_type*p,*t;initialize(total_pf);busypf_head=busypf_tail=NULL;for(i=0;total_instruction;i+)if(plpagei.pfn=INVALID)disaffe

11、ct+=1;If(freepf_head=NULL)p=busypf_head->next;plbusypf_head->pn.pfn=INVALID;freepf_head=busypf_head;freepf_head->next=NULL;busypf_head=p;p=freepf_head->next;freepf_head->next=NULL;freepf_head->pn=pagei;plpagei.pfn=freepf_head->pfn;if(busypf_tail=NULL) busypf_head=busypf_tail=fre

12、epf_head; else busypf_tail->next=freepf_head; busypf_tail=freepf_head; freepf_head=p; printf(“FIFO:%6.4f”,1-(float)diseffect/320);void LRU(total_pf)int total_pf; int min,minj,i,j,present_time; initialize(total_pf);present_time=0;for(i=0;i<total_instruction;i+) if(plpagei.pfn=INVALID) diseffect

13、+; if(freepf_head=NULL) min=32767; for(j=0;j<total_vp;j+) if(min>plj.time&&plj.pfn!=INVALID)min=plj.time;min j=j;freepf_head=&pfcplmin j.pfn;plminj.pfn=INVALID;plminj.time=-1;freepf_head->next=NULL; plpagei.pfn=freepf_head->pfn; plpagei.time=present_time; freepf_head=freepf_h

14、ead->next;else plpagei.time=present_time; present_time+;printf(“LRU:%6.4f”,1-(float)diseffect/320);void NUR(total_pf)int total_pf;int i,j,dp,cont_flag,old_dp;pfc_type*t;initiallze(total_pf);dp=0;for(i=o;i<total_instruction;i+)if(plpagei.pnf=INVALID)disaffect+;if(freep_head=NULL)cont_flag=TURE;

15、old_dp=dp;while(cont_flag)if(pldp.counter=0&&pldp.pfn!=INVALID)cont_flag=FALSE;elsedp+;if(dp=total_vp)dp=0;for(j=0;j<total_vp;j+)plj.counter=0;freepf_head=&pfcpldp.pnf;pldp.pnf=INVALD;freep_head->next=NULL);plpagei.pfn=freepf_head->pfn;freepf_head=freepf_head->next;elseplpage

16、i.counter=1;if(i%clear_period=0)for(j=0;j<total_vp;j+)plj.counter=0;printf(“NUR:%6.4f”,1-(float)disaffect/320);void OPT(total_pf)Inttotal_pf;intI,j,max,maxpage,d,disttotal_vp;pfc_type*t;initialize(total_pf);for(i=0;i<total_instruction;i+)if(plpagei.pnf=INVALID)disaffect+;if(freepf_head=NULL)fo

17、r(j=0;j<total_vp;j+)if(plj.pfn=INVALID)distj=32767;else distj=0;d=1;for(j=i+1;j<total_instruction;j+)if(plpagej.pfn!=INVALID)distpagej=d;d+;max=-1;for(j=0;j<total_vp;j+)if(max<distj) max=distj;Maxpage=j;freepf_head=&pfcplmaxpage.pfn;freepf_head->next=NULL;plmaxpage.pfn=INVALID;plp

18、agei.pfn=freepf_head->pfn;freepf_head=freepf_head->next;printf(“OPT:%6.4f”,1-(float)disaffect/320);Void LFU(total_pf)int total_pf; int i,j,min,minpage;pfc_type*t;initialize(total_pf);for(i=0;i<total_instruction;i+) if(plpagei.pfn=INVALID)disaffect+;if(freepf_head=NULL)min=32767;for(j=0;j<

19、;total_vp;j+)if(min>plj.counter&&plj.pfn!=INVALID)min=plj.counter;minpage=j;Plj.counter=0;freep_head=&pfcplminpage.pfn;plminpage.pfn=INVALID;freepf_head->next=NULL;plpagei.pfn=freepf_head->pfn;freepf_head=freepf_head->next;elsePlpagei.counter+;Printf(“LFU:%6.4f”,1-(float)dise

20、ffect/320);main()int s,i,j; srand(getpid()*10); S=319*rand()/32767+1; for(i=0;i<total_instruction;i+=4) ai=s; ai+1=ai+1; ai+2=ai*rand()/32767; ai+3=ai+2+1; s=rand()*(318-ai+2)/32767+ai+2+2;for(i=0;i<total_instruction;i+)pagei=ai%32; Offseti=ai%10;for(i=4;i<=32;i+)printf(“%2d page frames”,i)

21、; FIFO(i); LRU(i); OPT(i); LFU(i); NUR(i); printf(“n”);4.实验结果useruser-desktop:$./3 4page framesFIFO:0.4813LRU:0.48130PT:0.5437LFU:0.4844NUR:0.5062 5page framesFIFO:0.5250LRU:0.52810PT:0.5656LFU:0.5031NUR:0.5375 6page framesFIFO:0.5406LRU:0.54690PT:0.5781LFU:0.5219NUR:0.5312 7page framesFIFO:0.5594LR

22、U:0.55630PT:0.5938LFU:0.5469NUR:0.5312 8page framesFIFO:0.5687LRU:0.56560PT:0.6219LFU:0.5625NUR:0.5687 9page framesFIFO:0.6000LRU:0.57810PT:0.6406LFU:0.5781NUR:0.609410pageframesFIFO:0.6062LRU:0.60620PT:0.6562LFU:0.6000NUR:0.603111pageframesFIFO:0.6188LRU:0.61250PT:0.6719LFU:0.6156NUR:0.618812page f

23、ramesFIFO:0.6344LRU:0.62500PT:0.6906LFU:0.6312NUR:0.631213page framesFIFO:0.6469LRU:0.63750PT:0.7031LFU:0.6406NUR:0.631214page framesFIFO:0.6813LRU:0.65310PT:0.7188LFU:0.6531NUR:0.675015page framesFIFO:0.6906LRU:0.66870PT:0.7281LFU:0.6719NUR:0.700016page framesFIFO:0.7031LRU:0.68750PT:0.7500LFU:0.6781NUR:0.696917page framesFIFO:0.7250LRU:0.71560PT:0.7625LFU:0.7219NUR:0.725018page framesFIFO:0.7344LRU:0.73440PT:0.7812LFU:0.7344NUR:0.743819page framesFIFO:0.7469LRU:0.76250PT:0.7969LFU:0.7469NUR:0.753120page framesFIFO:0.7781LRU:0.77500PT:0.8031LFU:0.7656N