操作系统原理：C++模拟处理机调度实验三部曲（一）

算法（一）：FCFS 先来先服务法

FCFS原理:

C++代码：

#include
#include
#include
using namespace std;

/*定义进程控制块*/
typedef struct pcb
{
     
	char name;                    //进程名
	struct pcb *next;             //链接指针
	int arrivetime;               //到达时间
	int runtime;                  //估计运行时间
	char state;					  //进程状态（就绪R和完成C）
	int rank;                     //估计运行时间长短排序  
}PCB;

/*进程创建函数*/
void initPCB(PCB *P) {
     
	cout << "\nPlease input current PCB's name:";
	cin >> P->name;
	cout << "\nPlease input this PCB's arrivetime:";
	cin >> P->arrivetime;
	cout << "\nPlease input this PCB's runtime:";
	cin >> P->runtime;
	P->state = 'R';  
}

/*进程运行函数*/
void runPCB(PCB *P, int& time) {
     
	int tTime;                         //定义每个进程的周转时间

	while (time<P->arrivetime) {
     
		time++;
	}
	tTime = time - P->arrivetime;
	cout << "Time slice is " << time << ",Process " << P->name << " start," << endl;
	while (P->runtime > 0) {
     
		P->runtime--;
		time++;
	}	
	cout << "Time slice is " << time << ",Process " << P->name << " end." << endl;
	cout << "Process " << P->name << "'s turnaround time is " << tTime << endl;
	cout << "The remaining processes in the ready queue :" ;
	P->state = 'C';                    //程序置为完成态
	//输出等待队列里面剩余进程的进程名。
	while (P->next != NULL) {
     
		cout << P->next->name << "  ";
		P = P->next;
	}
	cout << endl;
	cout << endl;
}

///*进程打印函数*/
//void printPCB(PCB *P) {
     
//	cout << P->name << "周转时间为：" << endl;
//}

int Time = 0;
int time = 0;
int main() {
     
	PCB *head;                          //队首指针
	int process_num = 0, i, j;
	PCB P[5];
	PCB *PCB_line[5];
	for (i = 0; i < 5; i++)
	{
     
		PCB_line[i] = &P[i];
	}	
	cout << "开始进程创建~" << endl;
	for (; process_num < 5; process_num++) {
     
		cout << "创建第" << process_num + 1 << "个程序!" << endl;
		initPCB(PCB_line[process_num]);
		cout << "创建成功！" << endl;
	}
	cout << "所有进程创建结束！" << endl;
	cout << "当进程到达处理机时：" << endl;
	//用插入法创建队列，将它们按到达时间（arrivetime）从小到大排列
	PCB *temp;
	//用3个for循环将创建的5个进程按照到达时间（arrivetime）从小到大进行排序
	for (i = 0; i < 4; i++) {
     
		for (j = 0; j < 4 - i; j++) {
     
			/*if (PCB_line[j]->runtime > max->runtime) {
				max = PCB_line[j];
			}*/
			if (PCB_line[j]->arrivetime > PCB_line[j + 1]->arrivetime)eEWWW
			{
     
				temp = PCB_line[j];
				PCB_line[j] = PCB_line[j + 1];             //交换指针排序
				PCB_line[j + 1] = temp;
			}
		}
	}
	head = PCB_line[0];
	for (i = 0; i < 5-1; i++) {
      
		PCB_line[i]->next = PCB_line[i + 1];             //将所有链表链接在一起
	} 
	PCB_line[4]->next= NULL;

//进程运行
	process_num = 0;
	while (process_num < 5) {
     
		process_num++;
		cout << "第" << process_num << "个程序进入处理机。" << endl;
		time++;
		runPCB(PCB_line[process_num-1],time);
	}
	getchar();
	getchar();
	return 0;
} 

实验结果：

实验数据

---

进程名	进程达到时间	进程运行时间
A	5	11
B	4	11
C	3	11
D	2	11
E	1	11

实验结果

记2019年双十一，为什么我的女朋友还没来呢！(┬＿┬)
不管了~
Happy solo 耶！