BOOL AcceptEx(SOCKET       sListenSocket,SOCKET       sAcceptSocket,PVOID        lpOutputBuffer,DWORD        dwReceiveDataLength,DWORD        dwLocalAddressLength,DWORD        dwRemoteAddressLength,LPDWORD      lpdwBytesReceived,LPOVERLAPPED lpOverlapped
);

class IocpAcceptEx
{
public:IocpAcceptEx();~IocpAcceptEx();//设置回调接口。当accept成功，调用回调接口。void SetCallback(IAcceptCallback* callback);// 增加监听端口void AddListenPort(UINT16 port);//启动服务
    BOOL Start();void Stop();。。。以下代码省略
}
#define POST_ACCEPT 1
//使用IocpAcceptEx类，必须实现该接口。接收客户端的连接
class IAcceptCallback
{
public:virtual void OnAcceptClient(SOCKET hSocketClient, UINT16 nListenPort) = 0;
};

m_hIocp = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, NULL, 0);
if (m_hIocp == NULL)return FALSE;

    //生成套接字SOCKET serverSocket = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, WSA_FLAG_OVERLAPPED);if (serverSocket == INVALID_SOCKET){return false;}//绑定
    SOCKADDR_IN addr;memset(&addr, 0, sizeof(addr));addr.sin_family = AF_INET;addr.sin_addr.s_addr =  INADDR_ANY ;addr.sin_port = htons(port);if (bind(serverSocket, (sockaddr *)&addr, sizeof(addr)) != 0){closesocket(serverSocket);serverSocket = INVALID_SOCKET;return false;}//启动监听if (listen(serverSocket, SOMAXCONN) != 0){closesocket(serverSocket);serverSocket = INVALID_SOCKET;return false;}//监听端口与完成端口绑定if (CreateIoCompletionPort((HANDLE)serverSocket, m_hIocp, (ULONG_PTR)this, 0) == NULL){closesocket(serverSocket);serverSocket = INVALID_SOCKET;return false;}

struct AcceptOverlapped
{OVERLAPPED     overlap;INT32 opType;SOCKET serverSocket;SOCKET clientSocket;char lpOutputBuf[128];DWORD dwBytes;
};int IocpAcceptEx::NewAccept(SOCKET serverSocket)
{//创建socketSOCKET _socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); AcceptOverlapped *ov = new AcceptOverlapped();ZeroMemory(ov,sizeof(AcceptOverlapped));ov->opType = POST_ACCEPT;ov->clientSocket = _socket;ov->serverSocket = serverSocket;//存放网络地址的长度int addrLen = sizeof(sockaddr_in) + 16;int bRetVal = AcceptEx(serverSocket, _socket, ov->lpOutputBuf,0,addrLen, addrLen,&ov->dwBytes, (LPOVERLAPPED)ov);if (bRetVal == FALSE){int error = WSAGetLastError();if (error != WSA_IO_PENDING){closesocket(_socket);return 0;}}return 1;
}

    DWORD dwBytesTransferred;ULONG_PTR    Key;BOOL rc;int error;AcceptOverlapped *lpPerIOData = NULL;while (m_bServerStart){error = NO_ERROR;rc = GetQueuedCompletionStatus(m_hIocp,&dwBytesTransferred,&Key,(LPOVERLAPPED *)&lpPerIOData,INFINITE);if (rc == FALSE){error = 0;if (lpPerIOData == NULL){DWORD lastError = GetLastError();if (lastError == WAIT_TIMEOUT){continue;}else{assert(false);return lastError;}}}if (lpPerIOData != NULL){switch (lpPerIOData->opType){case POST_ACCEPT:{OnIocpAccept(lpPerIOData, dwBytesTransferred, error);}break;}}else {            }}return 0;　　

DWORD WINAPI IocpAcceptEx::AcceptExThreadPool(PVOID pContext)
{ThreadPoolParam *param = (ThreadPoolParam*)pContext;param->pIocpAcceptEx->NewAccept(param->ServeSocket);delete param;return 0;
}int IocpAcceptEx::OnIocpAccept(AcceptOverlapped *acceptData, int transLen, int error)
{m_IAcceptCallback->OnAcceptClient(acceptData->clientSocket, acceptData->serverSocket);//当一个AcceptEx返回，需要投递一个新的AcceptEx。 //使用线程池好像有点小题大做。前文已说过，套接字的创建相对是比较耗时的操作。//如果不在线程池投递AcceptEx，AcceptEx的优点就被抹杀了。ThreadPoolParam *param = new ThreadPoolParam();param->pIocpAcceptEx = this;param->ServeSocket = acceptData->serverSocket;QueueUserWorkItem(AcceptExThreadPool, this, 0);delete acceptData;return 0;
}