iocpserver.h

使用IOCP编写的可伸缩性的回显服务器

#ifndef __IOCPSERVER_H_
#define __IOCPSERVER_H_

#include <WINSOCK2.H>
#include <mswsock.h>

#define BUFFER_SIZE 1024*4		// I/O请求的缓冲区大小
#define MAX_THREAD	2			// I/O服务线程的数量 

//缓冲区对象 用来描述per-I/O数据
struct CIOCPBuffer
{
	WSAOVERLAPPED ol;
	SOCKET sClient;		//AcceptEx接收的客户方套接字
	char *buff;			//I/O操作使用的缓冲区
	int nLen;			//buff缓冲区(使用的)大小
	ULONG nSequenceNumber;//此I/O的序列号
	int nOperation;		//操作类型
#define OP_ACCEPT 1
#define OP_WRITE  2
#define OP_READ   3
	CIOCPBuffer *pNext;	
};

//per-Handle数据 它包含了一个套接字的信息
struct CIOCPContext
{
	SOCKET s;		//套接字句柄
	SOCKADDR_IN addrLocal;	//连接的本地地址
	SOCKADDR_IN addrRemote;	//连接的远程地址
	BOOL bClosing;	//套接字是否关闭
	int nOutstandingRecv;	//此套接字上抛出的重叠操作的数量
	int nOutstandingSend;
	ULONG nReadSequence;	//安排给接收的下一个序列号
	ULONG nCurrentReadSequence; //当前要读的序列号
	CIOCPBuffer *pOutOfOrderReads;	//记录没有按顺序完成的读I/O
	CRITICAL_SECTION Lock;	//保护这个结构
	CIOCPContext *pNext;
};

class CIOCPServer  // 处理线程
{
public:
	CIOCPServer();
	~CIOCPServer();

	//开始服务
	BOOL Start(int nPort = 4567, int nMaxConnections = 2000, int nMaxFreeBuffer = 200, \
			int nMaxFreeContexts = 100, int nInitialReads = 4);
	//停止服务
	void Shutdown();
	//关闭一个连接和关闭所有连接
	void CloseAConnection(CIOCPContext *pContext, CIOCPBuffer *pBuffer, int nError = NO_ERROR);
	void CloseAllConnections();
	//取得当前的连接数量
	ULONG GetCurrentConnection();
	//向指定客户发送文本
	BOOL SendText(CIOCPContext *pContext, char *pszText, int nLen);
protected:
	//申请和释放缓冲区对象
	CIOCPBuffer *AllocateBuffer(int nLen);
	void ReleaseBuffer(CIOCPBuffer *pBuffer);
	//申请和释放套接字上下文
	CIOCPContext *AllocateContext(SOCKET s);
	void ReleaseContext(CIOCPContext *pContext);
	//释放空闲缓冲区对象列表和空闲上下文对象列表
	void FreeBuffer();
	void FreeContexts();
	//向连接列表添加一个连接
	BOOL AddAConnection(CIOCPContext *pContext);
	//插入和移除未决的接受请求
	BOOL InsertPendingAccept(CIOCPBuffer *pBuffer);
	BOOL RemovePendingAccept(CIOCPBuffer *pBuffer);
	//取得下一个要读取的
	CIOCPBuffer *GetNextReadBuffer(CIOCPContext *pContext, CIOCPBuffer *pBuffer);
	//投递接受I/O、发送I/O、接收I/O
	BOOL PostAccept(CIOCPBuffer *pBuffer);
	BOOL PostSend(CIOCPContext *pContext, CIOCPBuffer *pBuffer);
	BOOL PostRecv(CIOCPContext *pContext, CIOCPBuffer *pBuffer);
	//事件通知函数
	void HandleIO(DWORD dwKey, CIOCPBuffer *pBuffer, DWORD dwTrans, int nError);

	//建立一个新的连接
	virtual void OnConnectionEstablished(CIOCPContext *pContext, CIOCPBuffer *pBuffer);
	//一个连接的关闭
	virtual void OnConnectionClosing(CIOCPContext *pContext, CIOCPBuffer *pBuffer);
	//在一个连接上发生了错误
	virtual void OnConnectionError(CIOCPContext *pContext, CIOCPBuffer *pBuffer, int nError);
	//在一个连接上的读操作完成
	virtual void OnReadCompleted(CIOCPContext *pContext, CIOCPBuffer *pBuffer);
	//一个连接上的写操作完成
	virtual void OnWriteCompleted(CIOCPContext *pContext, CIOCPBuffer *pBuffer);
protected:
	//记录空闲结构信息
	CIOCPBuffer *m_pFreeBufferList;
	int m_nFreeBufferCount;
	CRITICAL_SECTION m_FreeBufferListLock;

	CIOCPContext *m_pFreeContextList;
	int m_nFreeContextCount;
	CRITICAL_SECTION m_FreeContextListLock;

	//记录抛出的Accept请求
	CIOCPBuffer *m_pPendingAccepts;  //抛出请求列表
	long m_nPendingAcceptCount;
	CRITICAL_SECTION m_PendingAcceptsLock;

	//记录连接列表
	CIOCPContext *m_pConnectionList;
	int m_nCurrentConnection;
	CRITICAL_SECTION m_ConnectionListLock;

	//用于投递Accept请求
	HANDLE m_hAcceptEvent;
	HANDLE m_hRepostEvent;
	LONG m_nRepostCount;
	int m_nPort;  //服务器监听的端口
	int m_nInitialAccepts;
	int m_nInitialReads;
	int m_nMAxAccepts;
	int m_nMaxSends;
	int m_nMaxFreeBuffers;
	int m_nMaxFreeContexts;
	int m_nMaxConnections;
	HANDLE m_hListenThread;  //监听线程
	HANDLE m_hCompletion;	//完成端口句柄
	SOCKET m_sListen;	// 监听套接字句柄
	LPFN_ACCEPTEX m_lpfnAcceptEx;	//AcceptEx函数地址
	LPFN_GETACCEPTEXSOCKADDRS m_lpfnGetAcceptExSockaddrs; //GetAcceptExSockaddrs函数地址
	BOOL m_bShutDown; //用于通知监听线程退出
	BOOL m_bServerStarted; //记录服务是否启动
private:
	static DWORD WINAPI _ListenThreadProc(LPVOID lpParam);
	static DWORD WINAPI _WorkerThreadProc(LPVOID lpParam);
};

#endif