学步园

//有一个写者很多读者，多个读者可以同时读文件，但写者在写文件时不允许有读者在读文件，同样有读者在读文件时写者也不去能写文件。
#include <istream>
#include <Windows.h>
#include <process.h>

CRITICAL_SECTION gcs,buffer;
HANDLE readerover,writerover;
int m=0;//读者数量

BOOL SetConsoleColor(WORD wAttributes)
{
	HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
	if (hConsole == INVALID_HANDLE_VALUE)
		return FALSE;

	return SetConsoleTextAttribute(hConsole, wAttributes);
}

//读者线程输出函数
void readprint(char *pszformat,...)
{
	va_list p;
	va_start(p,pszformat);
	EnterCriticalSection(&gcs);
	vfprintf(stdout,pszformat,p);
	LeaveCriticalSection(&gcs);
	va_end(p);
}

//写者线程输出函数
void writerprint(char* psz)
{
	EnterCriticalSection(&gcs);
	SetConsoleColor(FOREGROUND_GREEN);
	printf("     %s\n",psz);
	SetConsoleColor(FOREGROUND_RED|FOREGROUND_GREEN|FOREGROUND_BLUE);
	LeaveCriticalSection(&gcs);
}


//写者
unsigned int __stdcall writer(LPVOID pm)
{
	writerprint("写者等待……");
	WaitForSingleObject(readerover,INFINITE);
	ResetEvent(writerover);
	writerprint("写者写数据开始……");
	Sleep(rand()%100);
	writerprint("写者写数据完毕……");
	SetEvent(writerover);
	return 0;
}
//读者
unsigned int __stdcall reader(LPVOID pm)
{
	readprint("     编号为%d的读者进入等待中...\n", GetCurrentThreadId());
	WaitForSingleObject(writerover,INFINITE);
	EnterCriticalSection(&buffer);
	m++;
	if (m ==1)ResetEvent(readerover);
	LeaveCriticalSection(&buffer);
	readprint("     编号为%d的读者读文件...\n", GetCurrentThreadId());
	Sleep(rand()%100);
	readprint("     编号为%d的读者读文件结束...\n", GetCurrentThreadId());
	EnterCriticalSection(&buffer);
	m--;
	if (m ==0) SetEvent(readerover);
	LeaveCriticalSection(&buffer);
	return 0;
}
void main()
{
	InitializeCriticalSection(&buffer);
	InitializeCriticalSection(&gcs);
	readerover = CreateEvent(NULL,FALSE,TRUE,NULL);
	writerover = CreateEvent(NULL,TRUE,TRUE,NULL);//第二个参数手动置位事件相当于教室门，教室门一旦打开（被触发），所以有人都可以进入直到老师去关上教室门（事件变成未触发）。自动置位事件就相当于医院里拍X光的房间门，门打开后只能进入一个人，这个人进去后会将门关上，其它人不能进入除非门重新被打开（事件重新被触发）。
	HANDLE han[10];
	for (auto i =0;i<2;i++)
	{
		han[i] = (HANDLE) _beginthreadex(NULL,0,reader,NULL,0,NULL);
	}
	han[2] =(HANDLE) _beginthreadex(NULL,0,writer,NULL,0,NULL);
	Sleep(50);
	for (auto i =3;i<10;i++)
	{
		han[i] = (HANDLE) _beginthreadex(NULL,0,reader,NULL,0,NULL);
	}
	HANDLE han1[10];
	han1[2] =(HANDLE) _beginthreadex(NULL,0,writer,NULL,0,NULL);
	Sleep(100);
	for (auto i =0;i<2;i++)
	{
		han1[i] = (HANDLE) _beginthreadex(NULL,0,reader,NULL,0,NULL);
	}
	
	for (auto i =3;i<10;i++)
	{
		han1[i] = (HANDLE) _beginthreadex(NULL,0,reader,NULL,0,NULL);
	}
	WaitForMultipleObjects(10,han1,TRUE,INFINITE);
	for (auto i =0;i<10;i++)
	{
		CloseHandle(han[i]);
		CloseHandle(han1[i]);
	}
	CloseHandle(readerover);
	CloseHandle(writerover);
	DeleteCriticalSection(&gcs);
	DeleteCriticalSection(&buffer);
	system("pause");
}