C-实现进程调度算法-有先来先服务、优先级调度、短作业优先、响应比高优先(共12页).doc

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课程设计报告书实践课题：操作系统课程设计姓名：学号：完成时间：2010.6.28指导老师：（老师）一、设计摘要利用C++,实现进程调度算法,有先来先服务、优先级调度、短作业优先、响应比高优先，进一步理解了进程调度各种算法的概念及含义。二、设计背景在OS中，调度的实质是一种资源分配，调度算法即指：根据系统的资源分配策略所规定的资源分配算法。对于不同的系统和系统目标，通常采用不同的调度算法，如在批处理系统中，为照顾为数众多的短作业，采用短作业有限调度算法；在分时系统中，为保证系统具有合理的响应时间，采用轮转法进行调度。采用算法时，则要考虑多方面因素，以便达到最佳效果。三、主要技术/算法简介#include<iostream>using namespace std;#define MAX 10 struct task_struct{char name[10];/*进程名称*/int number;/*进程编号*/float come_time;/*到达时间*/float run_begin_time;/*开始运行时间*/float run_time;/*运行时间*/float run_end_time;/*运行结束时间*/int priority;/*优先级*/int order;/*运行次序*/int run_flag;/*调度标志*/}tasks[MAX];int counter;/*实际进程个数*/int fcfs();/*先来先服务*/int ps();/*优先级调度*/int sjf();/*短作业优先*/int hrrn();/*响应比高优先*/int pinput();/*进程参数输入*/int poutput();/*调度结果输出*/void main(){int option;pinput();printf("请选择调度算法（0~4）:\n");printf("1.先来先服务\n");printf("2.优先级调度\n");printf("3.短作业优先\n");printf("4.响应比高优先\n");printf("0.退出\n");scanf("%d",&option);switch(option){case 0:printf("运行结束。\n");break;case 1:printf("对进程按先来先服务调度。\n\n");fcfs();poutput();break;case 2:printf("对进程按优先级调度。\n\n");ps();poutput();break;case 3:printf("对进程按短作业优先调度。\n\n");sjf();poutput();break;case 4:printf("对进程按响应比高优先调度。\n\n");hrrn();poutput();break;}}int fcfs()/*先来先服务*/{float time_temp=0;int i;int number_schedul;time_temp=tasks[0].come_time;for(i=0;i<counter;i++){tasks[i].run_begin_time=time_temp;tasks[i].run_end_time=tasks[i].run_begin_time+tasks[i].run_time;tasks[i].run_flag=1;time_temp=tasks[i].run_end_time;number_schedul=i;tasks[number_schedul].order=i+1;}return 0;}int ps()/*优先级调度*/{float temp_time=0;int i=0,j;int number_schedul,temp_counter;int max_priority;max_priority=tasks[i].priority;j=1;while((j<counter)&&(tasks[i].come_time==tasks[j].come_time)){if(tasks[j].priority>tasks[i].priority){max_priority=tasks[j].priority;i=j;}j++;}/*查找第一个被调度的进程*//*对第一个被调度的进程求相应的参数*/number_schedul=i;tasks[number_schedul].run_begin_time=tasks[number_schedul].come_time;tasks[number_schedul].run_end_time=tasks[number_schedul].run_begin_time+tasks[number_schedul].run_time;tasks[number_schedul].run_flag=1;temp_time=tasks[number_schedul].run_end_time;tasks[number_schedul].order=1;temp_counter=1;while(temp_counter<counter){max_priority=0;for(j=0;j<counter;j++){if((tasks[j].come_time<=temp_time)&&(!tasks[j].run_flag))if(tasks[j].priority>max_priority){max_priority=tasks[j].priority;number_schedul=j;}}/*查找下一个被调度的进程*//*对找到的下一个被调度的进程求相应的参数*/tasks[number_schedul].run_begin_time=temp_time;tasks[number_schedul].run_end_time=tasks[number_schedul].run_begin_time+tasks[number_schedul].run_time;tasks[number_schedul].run_flag=1;temp_time=tasks[number_schedul].run_end_time;temp_counter++;tasks[number_schedul].order=temp_counter;}return 0;}int sjf()/*短作业优先*/{float temp_time=0;int i=0,j;int number_schedul,temp_counter;float run_time;run_time=tasks[i].run_time;j=1;while((j<counter)&&(tasks[i].come_time==tasks[j].come_time)){if(tasks[j].run_time<tasks[i].run_time){run_time=tasks[j].run_time;i=j;}j++;}/*查找第一个被调度的进程*//*对第一个被调度的进程求相应的参数*/number_schedul=i;tasks[number_schedul].run_begin_time=tasks[number_schedul].come_time;tasks[number_schedul].run_end_time=tasks[number_schedul].run_begin_time+tasks[number_schedul].run_time;tasks[number_schedul].run_flag=1;temp_time=tasks[number_schedul].run_end_time;tasks[number_schedul].order=1;temp_counter=1;while(temp_counter<counter){for(j=0;j<counter;j++){if((tasks[j].come_time<=temp_time)&&(!tasks[j].run_flag)){run_time=tasks[j].run_time;number_schedul=j;break;}}for(j=0;j<counter;j++){if((tasks[j].come_time<=temp_time)&&(!tasks[j].run_flag))if(tasks[j].run_time<run_time){run_time=tasks[j].run_time;number_schedul=j;}}/*查找下一个被调度的进程*//*对找到的下一个被调度的进程求相应的参数*/tasks[number_schedul].run_begin_time=temp_time;tasks[number_schedul].run_end_time=tasks[number_schedul].run_begin_time+tasks[number_schedul].run_time;tasks[number_schedul].run_flag=1;temp_time=tasks[number_schedul].run_end_time;temp_counter++;tasks[number_schedul].order=temp_counter;}return 0;}int hrrn()/*响应比高优先*/{int j,number_schedul,temp_counter;float temp_time,respond_rate,max_respond_rate;/*第一个进程被调度*/tasks[0].run_begin_time=tasks[0].come_time;tasks[0].run_end_time=tasks[0].run_begin_time+tasks[0].run_time;temp_time=tasks[0].run_end_time;tasks[0].run_flag=1;tasks[0].order=1;temp_counter=1;/*调度其他进程*/while(temp_counter<counter){max_respond_rate=0;for(j=1;j<counter;j++){if((tasks[j].come_time<=temp_time)&&(!tasks[j].run_flag)){respond_rate=(temp_time-tasks[j].come_time)/tasks[j].run_time;if(respond_rate>max_respond_rate){max_respond_rate=respond_rate;number_schedul=j;}}}/*找响应比高的进程*/tasks[number_schedul].run_begin_time=temp_time;tasks[number_schedul].run_end_time=tasks[number_schedul].run_begin_time+tasks[number_schedul].run_time;temp_time=tasks[number_schedul].run_end_time;tasks[number_schedul].run_flag=1;temp_counter+=1;tasks[number_schedul].order=temp_counter;}return 0;}int pinput()/*进程参数输入*/{int i;printf("please input the process counter:\n");scanf("%d",&counter);for(i=0;i<counter;i++){printf("******************************************\n");printf("please input the process of%d th:\n",i+1);printf("please input the name:\n");scanf("%s",tasks[i].name);printf("please input the number:\n");scanf("%d",&tasks[i].number);printf("please input the come_time:\n");scanf("%f",&tasks[i].come_time);printf("please input the run_time:\n");scanf("%f",&tasks[i].run_time);printf("please input the priority:\n");scanf("%d",&tasks[i].priority);tasks[i].run_begin_time=0;tasks[i].run_end_time=0;tasks[i].order=0;tasks[i].run_flag=0;}return 0;}int poutput()/*调度结果输出*/{int i;float turn_round_time=0,f1,w=0;printf("name number come_time run_time run_begin_time run_end_time priority order turn_round_time\n");for(i=0;i<counter;i++){f1=tasks[i].run_end_time-tasks[i].come_time;turn_round_time+=f1;w+=(f1/tasks[i].run_time);printf("%s,%d,%5.3f,%5.3f,%5.3f,%5.3f,%d,%d,%5.3f\n",tasks[i].name,tasks[i].number,tasks[i].come_time,tasks[i].run_time,tasks[i].run_begin_time,tasks[i].run_end_time,tasks[i].priority,tasks[i].order,f1);}printf("average_turn_round_timer=%5.2f\n",turn_round_time/counter);printf("weight_average_turn_round_timer=%5.2f\n",w/counter);return 0;}三、设计运行情况截图设有如下3个进程：进程名称。