rwlock.h

这是书上的代码

/////////////////////////////////////////////////////////////////////////////
//
//
//                        Copyright Declaration
//        
//            This source code is written by Huang Yifeng(China).
//       You can use the source code, but please reserve the Copyright
//       Declaration in this code. Or you should be ready to be punished
//       by the related law.
//
//                                                  Huang Yifeng
//                                              [e-mail]
//                                                    2003.7.8
//////////////////////////////////////////////////////////////////////////////



#ifndef __READER_WRITER_LOCK__
#define __READER_WRITER_LOCK__

#include "definition.h"


class CRWLock
{
public:
	CRWLock()
	{
		DataSemaphore.Create(1,200);
		ReaderCounter = 0;
	}
	~CRWLock()
	{
	}
	void ReaderAcquire()
	{
		ReaderMutex.Lock();
		ReaderCounter++;
		if(ReaderCounter==1)
			DataSemaphore.Acquire();
		ReaderMutex.Unlock();
	}
	void ReaderRelease()
	{
		ReaderMutex.Lock();
		ReaderCounter--;
		if(ReaderCounter==0)
			DataSemaphore.Release();
		ReaderMutex.Unlock();
	}
	void WriterAcquire()
	{
		DataSemaphore.Acquire();
	}
	void WriterRelease()
	{
		DataSemaphore.Release();
	}
private:
	CSemaphoreEx DataSemaphore;
	CMutexEx ReaderMutex;
	int ReaderCounter;
};

#endif