bufferqueue.h

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// BufferQueue.h: interface for the BufferQueue class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_BUFFERQUEUE_H__9DF6BAD7_769D_4482_BC1E_8CDDDED73C00__INCLUDED_)
#define AFX_BUFFERQUEUE_H__9DF6BAD7_769D_4482_BC1E_8CDDDED73C00__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#include "Buffer.h"

#ifdef WIN32
#include <Process.h>
#include <afxmt.h>
#else
#include <pthread.h>
#endif

#define BUFFERNUM 5

class BufferQueue  
{
public:
	BufferQueue();
	virtual ~BufferQueue();
	Buffer *getReadBuffer();
	Buffer *getWriteBuffer();
	bool moveReadBuffer(bool);
	bool moveWriteBuffer(bool);
	void invalidate();

protected:
	Buffer buffers[BUFFERNUM];
	int readPos;
	int num;
	bool validFlag;
	/*Define two events to synchronize between input thread and output thread
    **hFullEvent is defined for the circumstance when the buffer queue is full 
	**and input thread is waiting for output thread to retrieve data from buffer queue
	**hEmptyEvent is defined for the circumstance when the buffer queue is empty 
	**and output thread is waiting for input thread puts data in buffer queue  
	*/
#ifdef WIN32
	HANDLE hFullEvent; //event on buffer queue full
	HANDLE hEmptyEvent; //event on buffer queue empty
#else

#endif
#ifdef WIN32
	CCriticalSection accessMutex; //Synchronize access to the buffer queue
#else
	pthread_mutex_t accessMutex = PTHREAD_MUTEX_INITIALIZER;
#endif
	int lockAccessMutex();
	int unLockAccessMutex();
	static int numOfBuffers(){return BUFFERNUM;}
};

#endif // !defined(AFX_BUFFERQUEUE_H__9DF6BAD7_769D_4482_BC1E_8CDDDED73C00__INCLUDED_)