进程调度算法有FIFO，优先数调度算法，时间片轮转调度算法，分级调度算法，目前主要是考虑FIFO和优先数调度算法（静态优先级）。
输入：进程流文件，其中存储的是一系列要执行的进程，
每个作业包括四个数据项： 进程名 进程状态(1就绪 2等待 3运行) 所需时间 优先数(0级最高) 输出: 进程执行流 和等待时间 平均等待时间 本程序包括:FIFO，优先数调度算法，时间片轮转调度算法
进程调度 #include < stdio.h > #include < string .h > #include < iostream.h > const int block_time = 10 ; // 定义时间片的长度为10秒 const int MAXPCB = 100 ; // 定义最大进程数 // 定义进程结构体 typedef struct node{ char name[ 20 ]; int status; int time; int privilege; int finished; int wait_time; }pcb; pcb pcbs[MAXPCB]; int quantity; // 初始化函数 void initial(){ int i; for (i = 0 ;i < MAXPCB;i ++ ){ strcpy(pcbs[i].name, "" ); pcbs[i].status = 0 ; pcbs[i].time = 0 ; pcbs[i].privilege = 0 ; pcbs[i].finished = 0 ; pcbs[i].wait_time = 0 ; } quantity = 0 ; } // 读数据函数 int readData(){ FILE * fp; char fname[ 20 ]; int i; cout << " 请输入进程流文件名: " ; cin >> fname; if ((fp = fopen(fname, " r " )) == NULL){ cout << " 错误,文件打不开,请检查文件名 " << endl; } else { while ( ! feof(fp)){ fscanf(fp, " %s %d %d %d " ,pcbs[quantity].name, & pcbs[quantity].status, & pcbs[quantity].time, & pcbs[quantity ].privilege); quantity ++ ; } // 输出所读入的数据 cout << " 输出所读入的数据 " << endl; cout << " 进程名 进程状态 所需时间 优先数 " << endl; for (i = 0 ;i < quantity;i ++ ){ cout << " " << pcbs[i].name << " " << pcbs[i].status << " " << pcbs[i].time << " " << pcbs[i].privilege << endl; } return ( 1 ); } return ( 0 ); } // 重置数据,以供另一个算法使用 void init() { int i; for (i = 0 ;i < MAXPCB;i ++ ){ pcbs[i].finished = 0 ; pcbs[i].wait_time = 0 ; } } // 先进先出算法 void FIFO() { int i,j; int total; // 输出FIFO算法执行流 cout << endl << " --------------------------------------------------------------- " << endl; cout << " FIFO算法执行流: " << endl; cout << " 进程名 等待时间 " << endl; for (i = 0 ;i < quantity;i ++ ){ cout << " " << pcbs[i].name << " " << pcbs[i].wait_time << endl; for (j = i + 1 ;j < quantity;j ++ ){ pcbs[j].wait_time += pcbs[i].time; } } total = 0 ; for (i = 0 ;i < quantity;i ++ ){ total += pcbs[i].wait_time; } cout << " 总等待时间: " << total << " 平均等待时间: " << total / quantity << endl; } // 优先数调度算法 void privilege() { int i,j,p; int passed_time = 0 ; int total; int queue[MAXPCB]; int current_privilege = 1000 ; for (i = 0 ;i < quantity;i ++ ){ current_privilege = 1000 ; for (j = 0 ;j < quantity;j ++ ){ if ((pcbs[j].finished == 0 ) && (pcbs[j].privilege < current_privilege)){ p = j; current_privilege = pcbs[j].privilege; } } queue[i] = p; pcbs[p].finished = 1 ; pcbs[p].wait_time += passed_time; passed_time += pcbs[p].time; } // 输出优先数调度执行流 cout << endl << " --------------------------------------------------------------- " << endl; cout << " 优先数调度执行流: " << endl; cout << " 进程名 等待时间 " << endl; for (i = 0 ;i < quantity;i ++ ){ cout << " " << pcbs[queue[i]].name << " " << pcbs[queue[i]].wait_time << endl; } total = 0 ; for (i = 0 ;i < quantity;i ++ ){ total += pcbs[i].wait_time; } cout << " 总等待时间: " << total << " 平均等待时间: " << total / quantity << endl; } // 时间片轮转调度算法 void timer() { int i,j,number,flag = 1 ; int passed_time = 0 ; int max_time = 0 ; int round = 0 ; int queue[ 1000 ]; int total = 0 ; while (flag == 1 ){ flag = 0 ; number = 0 ; for (i = 0 ;i < quantity;i ++ ){ if (pcbs[i].finished == 0 ){ number ++ ; j = i; } } if (number == 1 ){ queue[total] = j; total ++ ; pcbs[j].finished = 1 ; } if (number > 1 ){ for (i = 0 ;i < quantity;i ++ ){ if (pcbs[i].finished == 0 ){ flag = 1 ; queue[total] = i; total ++ ; if (pcbs[i].time <= block_time * (round + 1 )){ pcbs[i].finished = 1 ; } } } } round ++ ; } if (queue[total - 1 ] == queue[total - 2 ]){ total -- ; } cout << endl << " --------------------------------------------------------------- " << endl; cout << " 时间片轮转调度执行流: " ; for (i = 0 ;i < total;i ++ ){ cout << pcbs[queue[i]].name << " " ; } } // 显示版权信息函数 void version() { cout << endl << endl; cout << " ┏━━━━━━━━━━━━━━━━━━━━━━━┓ " << endl; cout << " ┃ 进程调度模拟系统 ┃ " << endl; cout << " ┠───────────────────────———————┨ " << endl; cout << " ┃ (c)All Right Reserved Neo ┃ " << endl; cout << " ┃ sony006@163.com ┃ " << endl; cout << " ┃ version 2004 build 1122 ┃ " << endl; cout << " ┗━━━━━━━━━━━━━━━━━━━━━━━┛ " << endl; cout << endl << endl; } // 主函数 void main() { int flag; version(); initial(); flag = readData(); if (flag == 1 ){ FIFO(); init(); privilege(); init(); timer(); } }