实验2进程状态转换及其PCB的变化1.目的自行编制模拟程序，通过形象化的状态显示，使学生理解进程的概念、进程之间的状态转换及其所带来的PCB内容、组织的变化，理解进程与其PCB间的一一对应关系。

2. 内容及要求1）设计并实现一个模拟进程状态转换及其相应PCB内容、组织结构变化的程序。

2）独立编写、调试程序。

进程的数目、进程的状态模型（三状态、五状态、七状态或其它）以及PCB的组织形式可自行选择。

3）合理设计与进程PCB相对应的数据结构。

PCB的内容要涵盖进程的基本信息、控制信息、资源需求及现场信息。

4）设计出可视性较好的界面，应能反映出进程状态的变化引起的对应PCB 内容、组织结构的变化。

5）代码书写要规范，要适当地加入注释。

6）鼓励在实验中加入新的观点或想法，并加以实现。

7）认真进行预习，完成预习报告。

8）实验完成后，要认真总结，完成实验报告。

3.程序流程图进程的三种基本状态及其转换如下图所示。

开始输入要执行的指令1？N 2？N 3？N 4？N 5？N 0？YY 结束N提示输入错误就绪队列已满？N创建进程Y提示就绪队列已满Y有进程处于运行状态?Y 该进程执行一个时间片后放回就绪队列N将就绪队列中优先级最高的进程放入运行队列有进程处于运行状态?Y该进程所需执行时间减1，并回到就绪队列Cputime++Y有进程处于运行状态？Y将该进程放入阻塞队列N提示无运行的进程输入事件发生的进程名称阻塞队列中有该进程？Y 将该进程放入就绪队列N提示该进程并未阻塞4.数据结构及说明在本实验中，主要的数据结构是PCB 的数据结构，具体如下： struct process{char name; //进程名称int needtime; //进程所需要的运行时间int priority; //进程的优先级};5.源程序#include<stdio.h>#include<stdlib.h>#include<string.h>struct process{char name;int needtime;int priority;};struct process readyQueue[5];struct process run;struct process blockedQueue[5];const struct process null={NULL,0,0};int readyQueueHead=0;int blockedQueueHead=0;int cpuState=0;int cpuTime=0;void Order(struct process parameter[],int head);//将队列中的进程按优先级排列int Creat();void Dispath();int Timeout();int EventWait();int EventOccur();void Order(struct process parameter[],int head){int k,i;struct process temp;for(k=0;k<head-1;k++){for(i=0;i<head-k-1;i++){if(parameter[i].priority>=parameter[i+1].priority){temp=parameter[i];parameter[i]=parameter[i+1];parameter[i+1]=temp;}}}}int Creat(){if(readyQueueHead>=5){printf("The Ready Queue has been full\n");return 0;}label1:printf(" input new process name(must be a letter): \n");scanf("%c",&(readyQueue[readyQueueHead].name));getchar();int k;for( k=0;k<readyQueueHead;k++)if(readyQueue[readyQueueHead].name==readyQueue[k].name||readyQueue[rea dyQueueHead].name==readyQueue[k].name+32||readyQueue[readyQueueHead].na me==readyQueue[k].name-32){printf("the process is already exist!\n");goto label1;}for( k=0;k<blockedQueueHead;k++)if(readyQueue[readyQueueHead].name==blockedQueue[k].name||readyQueue[r eadyQueueHead].name==blockedQueue[k].name+32||readyQueue[readyQueueHea d].name==blockedQueue[k].name-32){printf("the process is already exist!\n");goto label1;}if(readyQueue[readyQueueHead].name==||readyQueue[readyQueueH ead].name==+32||readyQueue[readyQueueHead].name==-32) {printf("the process is already exist!\n");goto label1;}printf("input needtime (input a int number):\n");label2:scanf("%d",&(readyQueue[readyQueueHead].needtime));getchar();if(readyQueue[readyQueueHead].needtime<1||readyQueue[readyQueueHead].n eedtime>100){printf("please input the true needtime(1--100)\n");goto label2;}printf(" input the priority(1--10): \n");label3:scanf("%d",&(readyQueue[readyQueueHead].priority));getchar();if(readyQueue[readyQueueHead].priority<1||readyQueue[readyQueueHead].prio rity>10){printf("please 1--10!\n");goto label3;}readyQueueHead++;Order(readyQueue,readyQueueHead);return 0;}void Dispath(){if (cpuState==0){readyQueueHead--;if(readyQueue[readyQueueHead].needtime>0){Order(readyQueue,readyQueueHead);run=readyQueue[readyQueueHead];readyQueue[readyQueueHead]=null;cpuState=1;}else printf("no process in the Ready Queue\n");}else {Timeout();Dispath();}}int Timeout(){cpuTime++;if (==NULL) return 0;readyQueue[readyQueueHead]=run;run=null;cpuState=0;readyQueue[readyQueueHead].needtime--;if(readyQueue[readyQueueHead].needtime==0){printf("The process '%c' has finished",readyQueue[readyQueueHead].name);readyQueue[readyQueueHead]=null;return 0;}readyQueueHead++;Order(readyQueue,readyQueueHead);return 0;}int EventWait(){if(blockedQueueHead>=5){printf("error:The Blocked Queue has been full\n");return 0;}if(cpuState==0){printf("error:no process in CPU");return 0;}run.needtime--;blockedQueue[blockedQueueHead]=run;blockedQueueHead++;run=null;cpuState=0;cpuTime++;printf("The process is blocked!\n");return 0;}int EventOccur(){if(readyQueueHead>=5){printf("The Ready Queue has been full\n");return 0;}printf("Please input the process name whose event occured!\n");char name=getchar();getchar();int i;struct process temp;for(i=0;i<blockedQueueHead;i++){if(name==blockedQueue[i].name){blockedQueueHead--;readyQueue[readyQueueHead]=blockedQueue[i];readyQueueHead++;blockedQueue[i]=blockedQueue[blockedQueueHead];blockedQueue[blockedQueueHead]=null;Order(readyQueue,readyQueueHead);printf("The process %c is ready!\n",name);return 0;}}if(i==blockedQueueHead){printf("error:This process has not been blocked!\n");}return 0;}int Show(){printf("\nCPU time:%d\n",cpuTime);printf(" name needtime priority\n");printf("Ready Queue: ");int i;if(readyQueue[0].name!=NULL)for(i=readyQueueHead;i>0;i--)printf("%c %d %d\n ",readyQueue[i-1].name,readyQueue[i-1].needtime,readyQueue[i-1].priority);else printf("null");printf("\nRunning Process: ");if(==NULL) printf("null");else printf("%c %d %d\n ",,run.needtime,run.priority);printf("\nBlock Queue: ");if(blockedQueue[0].name==NULL) printf("null");else for(i=blockedQueueHead;i>0;i--)printf("%c %d %d\n ",blockedQueue[i-1].name,blockedQueue[i-1].needtime,blockedQueue[i-1].priority); }int main(){SELECT:printf("\n\n1:input new process\n2:Dispath\n3:Timeout\n4:EventWait\n5:EventOccurs\n0:exit\n");int select=getchar();getchar();switch(select){case '1':Creat();Show();break;case '2':Dispath();Show();break;case '3':Timeout();Show();break;case '4':EventWait();Show();break;case '5':EventOccur();Show();break;case '0':exit(0);default:printf("Please select from 0 to 5\n");}goto SELECT;return 0;6.运行结果及其说明（1）创建进程：按‘1’创建进程，进程被放入就绪队列，并按优先级从高到低排列。