读者写者问题实现操作系统课程设计 第4页
#include <windows.h>
#include <conio.h>
#include "fstream.h"
int readcount=0; //读者数目
int writecount=0; //写者数目
CRITICAL_SECTION RP_Write; //临界区
CRITICAL_SECTION cs_Write;
CRITICAL_SECTION cs_Read;
struct ThreadInfo //线程信息
{ int Threadhao; //线程序号
char ThreadClass; //线程类别
double ThreadStartTime; //线程开始时间
double ThreadRunTime; //线程读写持续时间
};
void ReaderFun(char* file);//读者优先函数
void R_ReaderThread(void *p);//处理读者优先读者线程
void R_WriterThread(void *p);//处理读者优先写者线程
void WriterFun(char* file);
void W_ReaderThread(void *p);
void W_WriterThread(void *p);
int main()//主函数
{
char select;
while (true)
{
cout<<"***************本程序实现读者-写者问题*******\n"<<endl;
cout<<" 1:读者优先"<<endl;
cout<<" 2:写者优先"<<endl;
cout<<" 3:退出"<<endl;
cout<<"\n*********************************************"<<endl；
cout<<"请选择要进行的操作:"<<endl;
do
{
cin>>select;
if(select!='1' && select!='2' && select!='3')
cout<<"你操作有误，请重试！"<<endl;
}while (select!='1' && select!='2' && select!='3');
system("cls");
if (select=='3')
return 0;//退出
else if (select=='1')//调用读者优先
ReaderFun("peizhi.txt");
else if(select=='2')//调用写者优先
WriterFun("peizhi.txt");
cout<<"\n是否还有继续? 1. 继续 2.退出"<<endl;;
do
{
cin>>select;
if(select!='1' && select!='2' )
cout<<"你操作有误，请重试！"<<endl;
}while (select!='1' && select!='2');
if(select=='2')
return 0;// 退出
system("cls");
}
return 0;
}
//读者优先函数
void ReaderFun(char* file)
{
DWORD n_thread=0; //线程数初值为0
DWORD thread_ID; //线程ID
DWORD wait_for_all; //等待所有线程结束
//临界资源
HANDLE h_Mutex;
//互斥对象(h_Mutex)确保线程拥有对单个资源的互斥访问权
h_Mutex=CreateMutex(NULL,FALSE,"mutex_for_readcount");
HANDLE h_Thread[64]; //线程对象数组，最大64
ThreadInfo thread_info[64];
readcount=0;
InitializeCriticalSection(&RP_Write); //初始化临界区
ifstream inFile;
inFile.open(file);
cout<<"读者优先:\n"<<endl;
while (inFile)
{//读入每一个读者、写者的信息
inFile>>thread_info[n_thread].Threadhao
>>thread_info[n_thread].ThreadClass
>>thread_info[n_thread].ThreadStartTime
>>thread_info[n_thread].ThreadRunTime;
if (-1 == inFile.get())
break;
n_thread++;//线程数加一
}
for (int i=0;i<(int)(n_thread);i++)
{
if (thread_info[i].ThreadClass=='r')
//创建读者线程
h_Thread[i]=CreateThread(NULL,0,\
(LPTHREAD_START_ROUTINE)(R_ReaderThread),\
&thread_info[i],0,&thread_ID);
else
//创建写者线程
h_Thread[i]=CreateThread(NULL,0,\
(LPTHREAD_START_ROUTINE)(R_WriterThread),\
&thread_info[i],0,&thread_ID);
}
wait_for_all=WaitForMultipleObjects(n_thread,h_Thread,TRUE,-1);
cout<<"所有的读者和写者线程完成操作."<<endl;
}
//读者优先-----读者线程
void R_ReaderThread(void *p)
{
//互斥变量
HANDLE h_Mutex;
h_Mutex=OpenMutex(MUTEX_ALL_ACCESS,FALSE,"mutex_for_readcount");
DWORD wait_for_mutex; //等待互斥变量所有权
DWORD m_delay; //延迟时间
DWORD m_ThreadRunTime; //读文件持续时间
int m_Threadhao; //线程序号
m_Threadhao=((ThreadInfo *)(p))->Threadhao;
m_delay=(DWORD)(((ThreadInfo *)(p))->ThreadStartTime*100);
m_ThreadRunTime=(DWORD)(((ThreadInfo *)(p))->ThreadRunTime*100);
Sleep(m_delay); //延迟等待
cout<<"读者线程 "<<m_Threadhao<<" 发出读请求."<<endl;
//等待互斥对象通知
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