(一) 进程调度

￡神魔★判官ぃ 2021-12-22 09:49 230阅读 0赞

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

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 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();  
\}  
\}

转载于:https://www.cnblogs.com/FCWORLD/archive/2010/12/04/1896340.html

[ContractedBlock.gif]: https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif
[ExpandedBlockStart.gif]: /images/20211220/b9aa7f4e73e74abe8b5d8798d9924037.png