实验进程状态转换及其PCB的变化一、程序流程图：二、使用的数据结构及说明：在本实验中，主要用到的数据结构是PCB的结构，其中PCB的数据结构如下：struct PCB{int P_Id; //PCB的ID号char P_Name[10]; //PCB的名称char P_State[10]; //PCB状态int P_Runtime; //PCB的所需要的运行时间int P_Requiry; //PCB所需要的资源要求struct PCB * next ; //PCB块的下一个指针} ;其中，P_Id,和P_Name用来标示一个进程，而P_State用来标示进程的五种状态：Create_state,Ready_state,Block_state,Run_state,Exit_state。

P_Runtime标示要完成一个进程所需要的时间。

P_Requiry标示一个进程的执行所需要的其他条件，当其他的条件满足，则P_Requiry 置1，否则置0。

Struct PCB * next 用来指向同一队列中的下一个PCB块。

三、程序源代码:#include"stdlib.h"#include"stdio.h"#include"string.h"/********** globle structure and viable ******/struct PCB{int P_Id; //PCB的ID号char P_Name[10]; //PCB的名称char P_State[10]; //PCB状态int P_Runtime; //PCB的所需要的运行时间int P_Requiry; //PCB所需要的资源要求struct PCB * next ; //PCB块的下一个指针} ;struct PCB * Create_state; //创建状态struct PCB * Run_state; //运行状态struct PCB * Ready_state; //就绪状态struct PCB * Block_state; //阻塞状态struct PCB * Exit_state; //退出状态int signal4=0; //标示进程4的完成状态int signal5=0; //标示进程5的完成状态void InsertQueue(struct PCB **head,struct PCB *node) /* insert node function */{struct PCB * p,*q;node->next=NULL;if(*head==NULL) //如果队列为空{*head=node;}Else //队列不空{p=*head;q=p->next;while(q!=NULL) //找到最后的元素位置{p=q;q=q->next;}p->next=node; //将节点插入队列}void DeleteQueue(struct PCB **head,struct PCB *node) //撤销进程，从队列中删除元素{struct PCB *p,*q;q=*head;if(*head==NULL||node==NULL) //如果队列为空，返回return ;if(*head==node) //如果要删除的元素是队首元素{*head=(*head)->next;return;}Else //如果不是队列的首元素{while(q->next!=p&&q->next!=NULL)q=q->next;q=p->next;p->next=NULL;}}void Display_Process(struct PCB * node) //打印进程状态的元素函数{printf("\n\nthis process Id is : %d \n",node->P_Id);printf("this process name is : %s \n",node->P_Name);printf("this process state is : on %s \n ",node->P_State);printf("this process Runtime is : %d \n",node->P_Runtime);if(node->P_Requiry)printf("this process resource is ready \n");elseprintf("this process resource is not ready ! \n");}void DispatchToBlock(struct PCB *node) // /* dispatch to block function*/{ //调度到阻塞状态的函数//struct PCB *p=(struct PCB *)malloc(sizeof(struct PCB));if(!node->P_Requiry) //如果所需要的资源没有满足则，调度到阻塞状态{strcpy(node->P_State,"block");InsertQueue(&Block_state,node); //插入到阻塞队列Display_Process(node);}void DispatchToReady(struct PCB *node) // dispatch to ready state{ //调度到就绪状态的函数if(node->P_Requiry) //如果所需的资源满足，则调度{strcpy(node->P_State,"Ready");InsertQueue(&Ready_state,node);Display_Process(node);}}void DispatchBlockToReady() //dispatch the process to readyqueue{ //从阻塞状态调度到就绪状态函数struct PCB*p,*q;q=Block_state;while(q!=NULL) //如果阻塞状态队列不空{p=q;q=q->next;if(signal4&&p->P_Id==4) //如果所需要的资源满足{DeleteQueue(&Block_state,p);strcpy(p->P_State,"ready");InsertQueue(&Ready_state,p);printf("process4 will be in the state of ready!\n");Display_Process(p);}if(signal5&&p->P_Id==5){DeleteQueue(&Block_state,p);strcpy(p->P_State,"ready");InsertQueue(&Ready_state,p);printf("process5 will be in the state of ready!\n");Display_Process(p);}}}void Create_Process() //创建进程函数{int i;struct PCB *p;char name[10];strcpy(name,"process");for(i=1;i<3;i++) //动态创建2个处于阻塞状态的进程{p=(struct PCB *)malloc(sizeof(struct PCB));p->P_Id=i;name[7]=i+'0';name[8]='\0';strcpy(p->P_Name,name);strcpy(p->P_State,"create");p->P_Runtime=1; //所需要的时间片为1p->P_Requiry=0;Display_Process(p);sleep(4);printf(" \n process%d will be in the state of Block, waiting the resource ready \n\n",i);DispatchToBlock(p); //同时调度到阻塞队列}for(i=3;i<7;i++) //创建4个就绪状态的队列{p=(struct PCB *)malloc(sizeof(struct PCB));p->P_Id=i;name[7]=i+'0';name[8]='\0';strcpy(p->P_Name,name);strcpy(p->P_State,"create");p->P_Requiry=1;if(i==6) //在这里个进程6所需要的时间片为2p->P_Runtime=2;elsep->P_Runtime=1;Display_Process(p);sleep(4);printf(" \n process%d will be in the state of Ready, waiting to run \n\n",i);DispatchToReady(p);}}void display(struct PCB **head) //打印各个状态队列里进程数目{struct PCB *p,*q;p=*head;while(p!=NULL){sleep(2);//printf("\n\n///////////////////////////////////\n");printf("\n\nthis process Id is : %d \n",p->P_Id);printf("this process name is : %s \n",p->P_Name);printf("this process state is : on %s \n ",p->P_State);printf("this process Runtime is : %d \n",p->P_Runtime);if(p->P_Requiry)printf("this process resource is ready \n");elseprintf("this process resource is not ready ! \n");p=p->next;}}void Process_Run() //进程运行函数{struct PCB *p,*q;p=Ready_state;q=p;while(p!=NULL) //就绪队列不空则继续执行{if(p->P_Runtime<=0) break; //如果时间片执行完了，则跳出循环strcpy(p->P_State,"running");Display_Process(p);p->P_Runtime=p->P_Runtime-1;sleep(4);if(p->P_Runtime>0) //没有完成，则进入就绪队列{printf("this process is not finished,will be dispatch to the ready queue!!\n");DeleteQueue(&Ready_state,p);strcpy(p->P_State,"ready");InsertQueue(&Ready_state,p);Display_Process(p);}Else //执行完成，则跳出，并发送相应的信息{printf("\n\nProcess%d is finished and will be in the state of exit!\n\n",p->P_Id);if(p->P_Id==4) signal4=1;if(p->P_Id==5) signal5=1;}if(signal4||signal5)DispatchBlockToReady(); //如果资源满足，则将进程调度到就绪队列q=q->next;p=q;}if(q==NULL)printf("\nthere is no process ready!\n STOP Machine!!!\n");}int main(int argc,char * argv[]) //主函数{int i;char c='c'; //界面printf("\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ \n");printf("...................................Ding Hai bo\n");printf("......Press s to start the process.......\n");scanf("%c",&c);while(1){if(c=='s')break;scanf("%c",&c);}Create_Process(); //调用创建进程函数printf("\n>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");printf("\n>>>>>>> Display the Ready queue >>>>>>>>>>>>>>>\n");sleep(5);display(&Ready_state); ////////////////显示就绪队列里的进程printf("\n>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");printf("\n>>>>>>>> Display the Block queue >>>>>>>>>>>>\n");sleep(5); //显示阻塞队列函数display(&Block_state); /////////////////////printf("\n>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n\n\n");printf("\n>>>>>>>> Now the process start to run >>>>>>>>>>>\n");sleep(5);Process_Run(); //调用进程运行函数}四、运行结果及说明：运行结果的截图：下面的运行结果是程序执行的每一步进程调度的显示，从进程的创建到进程的执行，结束，每一步进程调度都有显示。