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1、精选优质文档-倾情为你奉上学年第 学期 操作系统 课程实 验 报 告学 院： 专 业： 班 级： 姓 名： 学 号： 任课教师： 专心-专注-专业实验题目处理机调度实验地点实验目的1.通过编写程序实现进程或作业先来先服务、高优先权、按时间片轮转调度算法，进一步掌握进程调度的概念和算法，加深对处理机分配的理解。 2.了解Linux中进程（线程）的调度机制。3.学习使用Linux中进程（线程）调度算法，掌握相应的与调度有关的函数。实验内容1、程序说明:(1)先来先服务算法：如果早就绪的进程排在就绪队列的前面，迟就绪的进程排在就绪队列的后面，那么先来先服务（FCFS：first come first
2、 service）总是把当前处于就绪队列之首的那个进程调度到运行状态。(2)轮转法就是按一定时间片(记为q)轮番运行各个进程。如果q是一个定值，则轮转法是一种对各进程机会均等的调度方法。(3)优先级调度的基本思想是，把当前处于就绪队列中优先级最高的进程投入运行，而不管各进程的下一个CPU周期的长短和其他因素。2、具体步骤: (1)分析问题，提出解决问题的算法(2)编制程序(3)程序调试(4)记录实验结果，以及思考是否能够改善算法（1）编辑程序jcdd.c，编译并执行。#include #include #define P_NUM 5#define P_TIME 50enum stateread
3、y,execute,block,finish;struct pcbbchar name4;int priority; /数越大优先级越高int cputime; /已占用CPU的时间int needtime; /执行时间int count;enum state process;struct pcbb *next;typedef struct pcbb pcb;void display_menu()printf(CHOOSE THE ALGORITHM:n);printf(1 PRIORITYn);printf(2 ROUNDROBINn);printf(3 EXITn);pcb* get_pr
4、ocess()pcb *q;pcb *p; /头指针pcb *t; /尾指针int i = 0;printf(input name and timen);while (i name);scanf(%d,&q-needtime);q-cputime = 0;q-priority = P_TIME - q-needtime;q-process = ready;q-next = NULL;if(i=0)p = q;t = q;elset-next = q;t = q;i+;return p;void free_process(pcb *p)pcb *q;while(p!= NULL)q = p;p
5、= p-next;free(q);void display(pcb *p)printf(name cputime needtimepriority staten);while(p)printf(%s,p-name);printf( );printf(%d,p-cputime);printf( );printf(%d,p-needtime);printf( );printf(%d,p-priority);printf( );switch(p-process)case ready:printf(readyn);break;case execute:printf(executen); break;c
6、ase block:printf(blockn); break;case finish:printf(finishn); break;p = p-next;int process_finish(pcb *q)int b1 = 1;while(b1&q)b1 = b1&q-needtime=0;q = q-next;return b1;void cpuexe(pcb *q)pcb *t = q;int tp = 0;while(q) /让t指向优先级最高的进程if (q-process!=finish)q-process = ready;if(q-needtime=0)q-process = f
7、inish;if(tppriority&q-process!=finish)tp = q-priority;t = q;q = q-next;if(t-needtime!=0)t-priority -=3; /每执行一次优先级降低三个单位t-needtime -;t-process = execute;t-cputime+;void priority_cal()pcb *p;p = get_process();int cpu = 0;while(!process_finish(p) /就绪队列中还有进程cpu+;printf(cputime:%dn,cpu);cpuexe(p); /选择优先级
8、最高的进程执行一个时间单位display(p); /每调度一次就显示次sleep(2);free_process(p); /释放所有进程printf(All processes have finishedn);pcb *get_process_round()pcb *q;pcb *p; /头指针pcb *t; /尾指针int i = 0;printf(input name and timen);while (iname);scanf(%d,&q-needtime);q-cputime = 0;q-count = 0;q-process = ready;q-next = NULL;if(i=0)
9、p = q;t = q;elset-next = q;t = q;i+;return p;void cpu_round(pcb *q)if(q-needtime=1) q-cputime+; else q-cputime +=2;q-needtime -=2;if(q-needtimeneedtime = 0;q-count+;q-process = execute;pcb *get_next(pcb *k,pcb *head)pcb *t;t = k;dot =t-next;while ( t & t-process = finish);if(t = NULL)t = head;/k是刚刚被
10、执行的节点,如果t-next=k,所明就绪队列除了k和t以外都已结束,按照时间片轮转算法,该t执行while(t-next!=k & t-process = finish)t = t-next;return t;void set_state(pcb *p)while(p)if(p-needtime = 0)p-process = finish;if(p-process = execute)p-process = ready;p = p-next;void display_round(pcb *p)printf(name cputime needtimecount staten);while(p
11、)printf(%s,p-name);printf( );printf(%d,p-cputime);printf( );printf(%d,p-needtime);printf( );printf(%d,p-count);printf( );switch(p-process)case ready:printf(readyn);break;case execute:printf(executen); break;case block:printf(blockn); break;case finish:printf(finishn); break;p = p-next;void round_cal
12、()pcb *p;pcb *r;p = get_process_round();int cpu = 0;r=p;while(!process_finish(p) /就绪队列中还有进程if(r-needtime=1)cpu+=1;elsecpu+=2; /时间片长度是2cpu_round(r);r = get_next(r,p); /获得下一个需要执行的进程printf(cputime:%dn,cpu);display_round(p); /每调度一次就显示次set_state(p);sleep(2);free_process(p); /释放所有进程main()display_menu();in
13、t k;scanf(%d,&k);switch(k)case 1:priority_cal();break;case 2:round_cal();break;case 3: break;default:printf(YOU HAVE NOT CHOOSE ANY ALGORITHM!n);（2）编辑程序先来先服务调度算法 fcfs.c,编译并执行。#include #include int SUM=0,K=0;typedef struct link int time; int averageTime; int priority; struct link *next;linknode;linkn
14、ode *creat()int n,m;linknode *head,*r,*s;head=r=(linknode *)malloc(sizeof(linknode);printf(输入各进程的处理时间和优先级并以两个0为结束标志:n); while(scanf(%d %d,&n,&m)&n&m)s=(linknode *)malloc(sizeof(linknode);K+;s-time=n;s-priority=m;s-averageTime=0;r-next=s;r=s;r-next=NULL;return head;linknode *seekAverageTime(linknode
15、*head)int sum=0;linknode *p;p=head-next;while(p)sum=sum+p-time; p-averageTime=sum;p=p-next; SUM+=sum;void print(linknode *head)linknode *p;p=head-next;printf(各进程处理时间为：); while(p)printf(%-4d,p-averageTime);p=p-next;printf(n);main()linknode *head;head=creat();seekAverageTime(head);print(head);printf(平均处理时间为：%dn,(SUM/K); 实验结果（1）优先级调度（2）时间片轮转调度（3）先来先服务调度遇到问题及解决方法