缓冲池模拟与实现

长春理工大学大学学生实验报告书学生用表实验名称缓冲池的模拟实现课程名称操作系统课程号学院(系) 软件学院专业软件工程班级学生姓名学号实验地点实验日期一、实验目的1掌握缓冲池的结构2掌握缓冲池的使用方法二、实验内容 1、实现输入、计算、输出进程并发执行2、实现getBuf和putBuf函数。

三、实验步骤 1、整体设计包括三个线程的模拟设计三个队列的链表设计还有三个队列的同步与互斥的设计等2、由于本次实验没有需要太多的数据结构因此数据结构的设计就只有三个缓冲队列的设计先构造一个空的缓冲队列该队列是一个实体即是一个确定的有结点的链表它是模拟缓冲池的载体输入与输出队列在构造时只有它的头尾指针而没有它的实体这是因为它可以从空缓冲区里获得例如当计算线程要数据计算时便可从空队列里获取一个缓冲区作为输入缓冲使用再把它挂载到输入队列的队尾中去算法流程图实验内容如下//缓冲队列类型的定义#define EMQ 0 //空缓冲队列#define INQ 1 //输入缓冲队列#define OUTQ 2 //输出缓冲队列const int bufferpoolsize = 50; ////缓冲池大小,默认设置为50个//结束运行标志short int m_end ; GDOU-B-11-112//缓冲结构体的定义typedef struct Buffer{int BufNo; //缓冲区号int buf; //缓冲内容Buffer *next; //缓冲指向下一个指针} buffer;//线程函数声明DWORD WINAPI InputThreadFunc(LPVOID lpPara); //输入线程函数DWORD WINAPI OutputThreadFunc(LPVOID lpPara); //输出线程函数DWORD WINAPI CalThreadFunc(LPVOID lpPara); //计算线程函数//加入与摘取队列函数声明void putBuf(int type , buffer *buf); //挂载到队列尾buffer* getBuf(int type); //从队列头中摘取一个缓冲区//构造缓冲池函数的声明void ConstructBuffer();//线程的句柄HANDLE hInputT; //输入线程HANDLE hOutputT; //输出线程HANDLE hCalculateT; //计算线程//线程的IDDWORD InputTid; //输入线程DWORD OutputTid; //输出线程DWORD CalculateTid; //计算线程//三个互斥量信号句柄HANDLE hmutexEMQ; //空队列的互斥信号量HANDLE hmutexOUTQ; //装满输出队列的互斥信号量HANDLE hmutexINQ; //装满输入队列的互斥信号量//三个同步信号量HANDLE hsemINQ;HANDLE hsemOUTQ;HANDLE hsemEMQ;#include "windows.h" #include "iostream" #include "stdlib.h"#include "time.h"#include "Main1.h"using namespace std;//三个缓冲队列头与尾指针buffer *hemq , *hinq , *houtq; //队头指针buffer *lemq , *linq , *loutq; //队尾指针//主函数int main(){cout<<show1<<endl<<show2<<endl<<show3<<endl<<endl; m_end = 1 ; //运行结束标志ConstructBuffer(); //构造缓冲池//创建互斥对象hmutexEMQ = CreateMutex(NULL,FALSE,NULL);hmutexOUTQ = CreateMutex(NULL,FALSE,NULL);hmutexINQ = CreateMutex(NULL,FALSE,NULL);//创建信号量对象hsemINQ = CreateSemaphore(NULL,0,bufferpoolsize,NULL);hsemOUTQ = CreateSemaphore(NULL,0,bufferpoolsize,NULL);hsemEMQ = CreateSemaphore(NULL,bufferpoolsize,bufferpoolsize,NULL);//创建线程hInputT = CreateThread(NULL,0,InputThreadFunc,NULL,0,&InputTid);Sleep(10);hCalculateT = CreateThread(NULL,0,CalThreadFunc,NULL,0,&CalculateTid); Sleep(10);hOutputT = CreateThread(NULL,0,OutputThreadFunc,NULL,0,&OutputTid);//Sleep(10000);//system("pause");if(getchar()){ //按回车后终止程序运行m_end = 0 ;cout<<"程序已经终止!"<<endl;}//等待三个线程的结束返回 WaitForSingleObject(hInputT,INFINITE); WaitForSingleObject(hCalculateT,INFINITE);WaitForSingleObject(hOutputT,INFINITE);//释放线程的资源CloseHandle(hInputT);CloseHandle(hCalculateT);CloseHandle(hOutputT);return 0;//输入线程函数的实现DWORD WINAPI InputThreadFunc(LPVOID lpPara) //输入线程函数{int nRandom;buffer* getbuf;srand(time(0)); //保证每次运行时产生的随机数独立while(m_end){Sleep(100);nRandom = rand()%100 + 1 ; //产生1到100的随机数//同步与互斥的控制WaitForSingleObject(hsemEMQ,INFINITE);WaitForSingleObject(hmutexEMQ,INFINITE);getbuf = getBuf(EMQ); //访问空队列getbuf->buf = nRandom ;cout<<"输入线程从 "<<"缓冲单元 "<<getbuf->BufNo<<"---收容输入--->"<<"data= "<<getbuf->buf<<endl;ReleaseMutex(hmutexEMQ); //释放互斥对象信号//控制访问输入队列的互斥量WaitForSingleObject(hmutexINQ,INFINITE);putBuf(INQ,getbuf) ; //将输入的缓冲区挂载到输入队列的队尾ReleaseMutex(hmutexINQ);ReleaseSemaphore(hsemINQ,1,NULL);return 0;}//输出线程函数的实现 DWORD WINAPI OutputThreadFunc(LPVOID lpPara) //输出线程函数{buffer* Outputbuf ; //一个临时交换区while(m_end){Sleep(100);////同步与互斥的控制WaitForSingleObject(hsemOUTQ,INFINITE);WaitForSingleObject(hmutexOUTQ,INFINITE);Outputbuf = getBuf(OUTQ) ; //从输出队列中提取一个提取输出缓冲区cout<<"输出线程从 "<<"缓冲单元 "<<Outputbuf->BufNo<<"---提取输出--->"<<"data= "<<Outputbuf->buf<<endl;//Outputbuf->buf = -1 ; //提取完成后将该缓冲区回收ReleaseMutex(hmutexOUTQ);WaitForSingleObject(hmutexEMQ,INFINITE);putBuf(EMQ,Outputbuf) ; //回收的把它挂载到空队列的队尾ReleaseMutex(hmutexEMQ);ReleaseSemaphore(hsemEMQ,1,NULL);}return 0;}//计算线程函数的实现DWORD WINAPI CalThreadFunc(LPVOID lpPara) //计算线程函数{buffer* Calbuf1 = NULL;buffer* Calbuf2 =NULL;int nCal;while(m_end){Sleep(10); //因为计算线程的速度远远快于输入与输出线程所以它的休眠时间应很小////同步与互斥的控制WaitForSingleObject(hsemINQ,INFINITE);WaitForSingleObject(hmutexINQ,INFINITE);Calbuf1 = getBuf(INQ); //从输入队列中提取一个收容输入缓冲区nCal = Calbuf1->buf; //提取数据cout<<"计算线程从 "<<"缓冲单元 "<<Calbuf1->BufNo<<"---提取输入--->"<<"data= "<<Calbuf1->buf<<endl;//Calbuf->buf = -1 ; //系统将收回此缓冲区表示该缓冲区已空ReleaseMutex(hmutexINQ);WaitForSingleObject(hmutexEMQ,INFINITE);putBuf(EMQ,Calbuf1);ReleaseMutex(hmutexEMQ);ReleaseSemaphore(hsemEMQ,1,NULL);nCal = nCal + 10000 ; //模拟输入数据的处理WaitForSingleObject(hsemEMQ,INFINITE);WaitForSingleObject(hmutexEMQ,INFINITE);Calbuf2 = getBuf(EMQ); //得到一个空的缓冲区作为收容输出Calbuf2->buf = nCal ; //存入运算结果cout<<"计算线程从 "<<"缓冲单元 "<<Calbuf2->BufNo<<"---收容输出--->"<<"data= "<<Calbuf2->buf<<endl;ReleaseMutex(hmutexEMQ);WaitForSingleObject(hmutexOUTQ,INFINITE); //把收容输出缓冲区挂载到输出队列的队尾putBuf(OUTQ,Calbuf2);ReleaseMutex(hmutexOUTQ);ReleaseSemaphore(hsemOUTQ,1,NULL);}return 0 ;}//从队列中得到队头结点函数(实际相当于删除一个结点操作) buffer* getBuf(int type){buffer* Returnbuf = NULL;switch(type){case 0 :{//判断该队列的缓冲个数是否还只有一个if(hemq != lemq && hemq->next->next != NULL){Returnbuf = hemq->next ; //取得队列头 hemq->next = Returnbuf->next; //修正队列链表头指针的指向Returnbuf->next = NULL;return Returnbuf;}else{//假如该缓冲队列的个数只有一个的话则使得队头指针与队尾指针相等级//这样的话就可以防止队尾指针的丢失Returnbuf = hemq->next ;hemq->next = Returnbuf->next;Returnbuf->next = NULL;lemq = hemq ;return Returnbuf;}}break;case 1:{if(hinq != linq && hinq->next->next != NULL) {Returnbuf = hinq->next;hinq->next = Returnbuf->next;Returnbuf->next =NULL;return Returnbuf;}else{Returnbuf = hinq->next ;hinq->next = Returnbuf->next; Returnbuf->next = NULL;linq = hinq;return Returnbuf;}}break;case 2:{if(houtq != loutq && houtq->next->next !=NULL ){Returnbuf = houtq->next ;houtq->next = Returnbuf->next; Returnbuf->next = NULL; return Returnbuf;}else{Returnbuf = houtq->next;houtq->next = Returnbuf->next ;Returnbuf->next = NULL;loutq = houtq;return Returnbuf;}}break;}//把某一类型的缓冲区挂载到队尾函数//(实际相当于插入一个结点操作)void putBuf(int type , buffer* buf){switch(type){case 0:{if(buf != NULL) //该参数(buf)不为空的时候才执行因为插入一个空的缓冲区是没有意义的{lemq->next = buf; //修正队列尾指针lemq = buf ; //队尾指针的跟踪lemq->next = NULL; //队列尾指针赋空 }}break;case 1:{if(buf != NULL) //同上{linq->next = buf;linq = buf;linq->next = NULL;}}break;case 2:{if(buf != NULL ){ loutq->next = buf;loutq = buf;loutq->next = NULL;}}break;}}//构造缓冲池函数的声明void ConstructBuffer(){buffer *p , *q; // 为开辟动态缓冲区而设的两个变量hemq = new buffer; //创建空队列的头指针hinq = new buffer; //创建输入队列的头指针houtq = new buffer; //创建输出队列的头指针q = hemq ;for(int i = 0 ; i < bufferpoolsize ; i++){p = new buffer; //开辟新的缓冲区p->BufNo = i; //给开辟的缓冲区编号p->buf = -1 ;q->next = p; //前一缓冲区指向新的缓冲区q = p; //q总是记住队尾的缓冲区}lemq = q ; //空缓冲区队尾指针的确定linq = hinq; //此时输入与输出队列的头指针与尾指针是一致的loutq = houtq;lemq->next = NULL;linq->next = NULL;loutq->next = NULL;}四、实验总结成绩指导教师日期注:请用A4纸书写不够另附纸。