先来先服务调度算法

1、FCFS先来先服务调度算法:#include#include#include#include#define MAX_POSSIBILITY 100 using namespace std;typedef struct PCBint sum;int PID;char Pname;bool state;int arrive_time;int start_time;int serve_time;int finish_time;创建进程PCB/头结点用于存放进程的总个数进程号进程名进程运行状态/进程到达时间进程开始时间进场服务时间进程完成时间float turn_around_time; /进程周转时

2、间float weight_turn_around_time; 进程带权周转时间 PCB *next;PCB;void InitHead(PCB *p)(PCB *q = p;q-PID=-1;q-Pname=-1;q-state=false;q-arrive_time=0;/指向下一个进程/ true代表未被执行初始化到达时间q-serve_time=0;随机产生进程服务时间q-start_time=0;有待于计算的时间q-finish_time=0;q-turn_around_time=0;q-weight_turn_around_time=0;q-next=NULL;void Creat

3、ePCB(PCB *p)随机创建进程int N,pid=0,arrive_time=0;char pname=A;cinN;创建的进程数PCB *head=p;head-sum=N;srand( (unsigned)time( NULL );设置随机数种子while(N-)PCB *q=(PCB *)malloc(sizeof(PCB);q-PID=pid;q-Pname=pname;q-state=true;/ true 代表未被执行q-arrive_time=arrive_time;初始化到达时间q-serve_time=rand() % MAX_POSSIBILITY; /随机产生进程服

4、务时间q-start_time=0;有待于计算的时间q-finish_time=0;q-turn_around_time=0;q-weight_turn_around_time=0;q-next=NULL;head-next=q;head=head-next;pid+;pname+;arrive_time+;void Run_FCFS(PCB *p)PCB *head=p;head-state=false;表示已经执行while(head-start_timearrive_time)head-start_time+;head-finish_time=head-start_time+head-s

5、erve_time;完成时间=开始时间+服务时间 head-turn_around_time=head-finish_time-head-arrive_time;/凋 转时间=完成-到达 head-weight_turn_around_time=head-turn_around_time/head-serve_time;if(head-next)head-next-start_time=head-finish_time; /下一个进程开始=这个进程的完成 cout进程号进程名运行状态到达时间服务时间开始时间完成时间周转时间带权周转时间endl;cout PIDt Pnamet statet arrive_timet serve_timet start_timet finish_timetturn_around_timetweight_turn_around_timetnnext; while(head) if(head-state) Run_FCFS(head); head=head-next; void main() PCB *