采用完成端口（IOCP）实现高性能网络服务器（Windows c++版）

//消息事件
enum Enum_MessageType :char
{
    EN_Accept = 0,
    EN_Read,
    EN_Close,
    EN_Connect
};

//返回的数据结构
class SocketMessage
{
public:
    UINT64         Index;
    SOCKET         Socket;
    Enum_MessageType MessageType;
    //当MessageType为EN_Connect时，BufferLen为EasyIocpLib_Connect函数的tag参数
    INT32 BufferLen;
    char *Buffer;
};

//不停的调用此函数，返回数据
SocketMessage* EasyIocpLib_GetMessage(UINT64 handle);

enum EN_SEND_BUFFER_RESULT
{
    en_send_buffer_ok = 0, //放入到发送缓冲
    en_not_validate_socket, //无效的socket句柄
    en_send_buffer_full     //发送缓冲区满
};

EN_SEND_BUFFER_RESULT EasyIocpLib_SendMessage(UINT64 handle, SOCKET socket,
        char* buffer, int offset, int len, BOOL mustSend = FALSE);

//完成端口操作类型
typedef enum
{
    POST_READ_PKG, //读
    POST_SEND_PKG, //写
    POST_CONNECT_PKG,
    POST_CONNECT_RESULT
}OPERATION_TYPE;


struct PER_IO_OPERATION_DATA
{
    WSAOVERLAPPED overlap; //第一个变量，必须是操作系统定义的结构
    OPERATION_TYPE opType;
    SOCKET         socket;
    WSABUF         buf;    //要读取或发送的数据
};

BOOL NetServer::PostRcvBuffer(SOCKET socket, PER_IO_OPERATION_DATA *overlap)
{
    DWORD flags = MSG_PARTIAL;
    DWORD numToRecvd = 0;

    overlap->opType = OPERATION_TYPE::POST_READ_PKG;
    overlap->socket = socket;

    int ret = WSARecv(socket,
        &overlap->buf,
        1,
        &numToRecvd,
        &flags,
        &(overlap->overlap),
        NULL);

    if (ret != 0)
    {
        if (WSAGetLastError() == WSA_IO_PENDING)
        {
            ret = NO_ERROR;
        }
        else
        {
            ret = SOCKET_ERROR;
        }
    }

    return (ret == NO_ERROR);
}

DWORD NetServer::Deal_CompletionRoutine()
{
    DWORD dwBytesTransferred;
    PER_IO_OPERATION_DATA *lpPerIOData = NULL;

    ULONG_PTR    Key;
    BOOL rc;
    int error;

    while (m_bServerStart)
    {
        error = NO_ERROR;
        //从完成端口获取事件
        rc = GetQueuedCompletionStatus(
            m_hIocp,
            &dwBytesTransferred,
            &Key,
            (LPOVERLAPPED *)&lpPerIOData,
            INFINITE);

        if (rc == FALSE)
        {
            error = 123;
            if (lpPerIOData == NULL)
            {
                DWORD lastError = GetLastError();
                if (lastError == WAIT_TIMEOUT)
                {
                    continue;
                }
                else
                {
                    //continue;
                    //程序结束
                    assert(false);
                    return lastError;
                }
            }
            else
            {
                if (GetNetResult(lpPerIOData, dwBytesTransferred) == FALSE)
                {
                    error = WSAGetLastError();
                }
            }
        }
        if (lpPerIOData != NULL)
        {
            switch (lpPerIOData->opType)
            {
                case POST_READ_PKG: //读函数返回
                {
                    OnIocpReadOver(*lpPerIOData, dwBytesTransferred, error);
                }
                break;

                case POST_SEND_PKG:
                {
                    OnIocpWriteOver(*lpPerIOData, dwBytesTransferred, error);
                }
                break;
            }
        }
        
    }
    return 0;
}

void NetServer::OnIocpReadOver(PER_IO_OPERATION_DATA& opData,
    DWORD nBytesTransfered, DWORD error)
{
    if (error != NO_ERROR || nBytesTransfered == 0)//socket出错 
    {
        Net_CloseSocket(opData.socket);
        NetPool::PutIocpData(&opData);//数据缓冲处理
    }
    else
    {
        OnRcvBuffer(opData, nBytesTransfered);//处理接收到的数据
        BOOL post = PostRcvBuffer(opData.socket, &opData); //再次读数据
        if (!post)
        {
            Net_CloseSocket(opData.socket);
            NetPool::PutIocpData(&opData);
        }
    }
}

BOOL NetServer::PostSendBuffer(SOCKET socket)
{
    if (m_clientManage.IsPostSendBuffer(socket)) //如果有正在执行的投递，不能再次投递
        return FALSE;

    //获取要发送的数据
    PER_IO_OPERATION_DATA *overlap = NetPool::GetIocpData(FALSE);
    int sendCount = m_clientManage.GetSendBuf(socket, overlap->buf);
    if (sendCount == 0)
    {
        NetPool::PutIocpData(overlap);
        return FALSE;
    }

    overlap->socket = socket;
    overlap->opType = POST_SEND_PKG;
    BOOL post = PostSendBuffer(socket, overlap);
    if (!post)
    {
        Net_CloseSocket(socket);
        NetPool::PutIocpData(overlap);
        return FALSE;
    }
    else
    {
        m_clientManage.SetPostSendBuffer(socket, TRUE);
        return TRUE;
    }
}