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

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 课程设计书 实践课题:姓 名:学 号:完成时间:指导老师: 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 1 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 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(); 2 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;itasks[i].run_begin_time=time_temp; tasks[i].run_end_time=tasks[i].run_begin_time+tasks[i].ru n_time; tasks[i].run_flag=1; time_temp=tasks[i].run_end_time; number_schedul=i; tasks[number_schedul].order=i+1; } 3 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 ((jif (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_countermax_priority=0; for(j=0;jif((tasks[j].come_timemax_priority) { max_priority=tasks[j].priority; number_schedul=j; } } /*查找下一个被调度的进程*/ 4 /*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 ((jif (tasks[j].run_timerun_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; 5 temp_time=tasks[number_schedul].run_end_time; tasks[number_schedul].order=1; temp_counter=1; while (temp_counterfor(j=0;jif((tasks[j].come_timerun_time=tasks[j].run_time;number_schedul=j;break;} } for(j=0;j{ if((tasks[j].come_time/*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; 6 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_countermax_respond_rate=0; for(j=1;jif((tasks[j].come_time{ 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); 7 for(i=0;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;if1=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, % 8 5.3f\n”,tasks[i].name,tasks[i].number,tasks[i].come_time,tas ks[i].run_time,tasks[i].run_begin_time,tasks[i].run_end_tim e,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: 注:”优先级”一栏，数字大的表示优先级越高。 根据本例 来运行本算法，结果如下: 1.输入进程有关参数 采用先来先服务算法: 采用优先级调度: 采用短作业优先: 采用高响应比优先: 四、心得体会 通过此次课程设计，更深入的理解了各个进程调度算法， 9 及实现 过程。在此过程中，遇到了困难，能及时请教同学，查询相关资料，及时解决了问题，但仍有不足之处，将会在今后学习中更加努力。 百度搜索“就爱阅读”,专业资料,生活学习,尽在就爱阅读网92to.com,您的在线图书馆 10