进程调度之动态高优先权优先（实验二）

进程：程序在一个数据集合上的动态执行，是系统进行资源分配和调度的独立单位。

动态高优先权优先：就绪进程在时间片上根据优先级的高低轮流执行，当进程结束或时间片结束，进程的优先级减小（相当于提高就绪队列中其他进程的优先级）重新回到就绪队列等待处理机。

模拟动态高优先权优先的C代码：

#include <stdio.h>#include <string.h>#include <stdlib.h>//#define OUTALLINFO#define Max 256#define time 1#define subb 1enum pathread_attr{ //进程的状态信息    runing = 1,    wait,    finsih};struct Pthread{ //描述进程信息  char *name;  int come_time;  int need_time;  int runing_time;  int priority;  double zz_time;  double dqzz_time;  enum pathread_attr attr;  struct Pthread *next;  Pthread() //默认构造函数  {      name = NULL;      come_time = 0;      runing_time  = need_time = 0;      zz_time = 0;      dqzz_time = 12.66;      priority = 0;      attr = wait;      next = NULL;  }  void get_info(int end_time) //计算周转时间，带权周转时间  {     this->zz_time = (end_time - this->come_time) * 1.0;     dqzz_time = zz_time / need_time;  }  void copy_queue(struct Pthread *temp) //拷贝进程信息  {      name = (char*)malloc(sizeof(char) * strlen(temp->name));      strcpy(name,temp->name);      come_time = temp->come_time;      need_time = temp->need_time;      runing_time = temp->runing_time;      priority = temp->priority;      attr = temp->attr;  }};int run_sum = 0; //统计进程的个数void init_pthread(struct Pthread *head,const char *name,const int come_time,const int need_time,const int priority) //初始化进程信息{    struct Pthread *temp = new Pthread();    temp->name = (char *) malloc(sizeof(char) * strlen(name));    strcpy(temp->name,name);    temp->come_time = come_time;    temp->need_time = need_time;    temp->runing_time = need_time;    temp->priority = priority;    temp->attr = wait;    temp->next = head->next;    head ->next = temp;    return;}void out_one(struct Pthread *temp) //输出一个进程信息{    printf("%s pathread info:\n",temp->name);#ifdef OUTALLINFO    printf("come_time: %d\n",temp ->come_time);    printf("need_time: %d\n",temp ->need_time);    switch(temp->attr){        case 1: printf("attr: waiting \n"); break;        case 2: printf("attr: runing \n"); break;        case 3: printf("attr: finsih \n"); break;    }    printf("priority: %d\n",temp->priority);#endif // OUTALLINFO    printf("周转时间: %0.2f\n",temp->zz_time);    printf("带权周转时间: %0.2f\n",temp->dqzz_time);    return;}void out_all(struct Pthread *head) //输出所有进程信息{    for(struct Pthread *p = head->next; p; p = p->next)        out_one(p);    return;}void add_queue(struct Pthread *head_temp,struct Pthread *head_queue) //添加进程到就绪队列{    struct Pthread *temp = new Pthread();    temp->copy_queue(head_temp);    temp->attr = wait;    struct Pthread *p = NULL;    for(p = head_queue; p ->next; p = p->next);    p->next = temp;    return;}void sqrt_queue(struct Pthread *head_queue) //根据进程优先级排序{    struct Pthread *p = head_queue ->next;    struct Pthread *q = NULL;    (head_queue) ->next = NULL;    for(struct Pthread *pp = p; p; ){        pp = p;        p = p ->next;        pp ->next = NULL;        for(q = head_queue; q ->next; q = q ->next){            if(q ->next->priority < pp ->priority){                pp->next = q->next;                q ->next = pp;                break;            }            if(q ->next->priority == pp ->priority){                    if(q->next->come_time > pp->come_time){                        pp->next = q->next;                        q ->next = pp;                        break;                    }            }        }        if(!q ->next)            q ->next = pp;    }    head_queue->attr = runing; //进程处于执行状态    return;}void queue_del(struct Pthread *head_queue) //从就绪队列删除一个进程{    if(!(head_queue ->next))        return;    head_queue ->next->attr = finsih;    out_one(head_queue ->next);    struct Pthread *p = head_queue ->next;    head_queue->next = p->next;    delete p;    return;}void mo_ni(struct Pthread *head,struct Pthread *head_queue) //模拟动态高优先权优先处理过程{    int run_i = 0,run_over = 0,time_runing = 0;    while(time_runing >= 0){        for(struct Pthread *p = head ->next; p; p = p->next) //检查此时刻是否有进程到达        if(time_runing == p->come_time)            add_queue(p,head_queue);        if(head_queue ->next){ //如果就绪队列非空            if(run_i == time && head_queue->next->runing_time){ //时间片结束&&进程为未完成                if(head_queue->next->priority){ //优先级非0                    head_queue->next->priority -= subb; //降低该进程的优先级                    if(head_queue->next->priority < 0) //如果小于0，则置为0                        head_queue->next->priority = 0;                }                    sqrt_queue(head_queue); //根据进程的优先级排序                    run_i = 0; //时间片置0            }            if(!head_queue->next->runing_time){ //如果进程执行结束                if(head_queue->next->priority){                    head_queue->next->priority -= subb;                    if(head_queue->next->priority < 0)                       head_queue->next->priority = 0;                       }                    head_queue->next->get_info(time_runing);                    queue_del(head_queue); //从就绪队列中删除该进程                    sqrt_queue(head_queue); //根据进程优先级排队                    run_i = 0; //时间片置0                    run_over++; //统计已经结束的进程个数            }           if(head_queue ->next) //如果有进程正在执行，服务时间减1            head_queue->next->runing_time--;            run_i++; //时间片加1        }        time_runing++;        if(run_over == run_sum) //如果处理完所有进程则结束模拟            return;    }    return;}int main(int argc,char *argv[]){    struct Pthread *head = new Pthread(); //进程链表    struct Pthread *head_queue = new Pthread(); //就绪态进程链表队列    char name[Max];    int come_time,need_time,priority;    FILE *input_file = fopen("C:\\Users\\chenhongyu\\Desktop\\test.txt","r"); //读取测试信息    printf("plase input name come_time need_time priority,if over,plase input [Ctrl + Z]\n\n");    while(fscanf(input_file,"%s%d%d%d",name,&come_time,&need_time,&priority) != EOF){        init_pthread(head,name,come_time,need_time,priority); //初始化进程链表        run_sum++; //统计总共多少个进程    }    mo_ni(head,head_queue); //模拟动态高优先权处理机的进程调度    return 0;}