Socket异步编程之基于事件

最新推荐文章于 2019-06-23 10:21:32 发布

segen_jaa

最新推荐文章于 2019-06-23 10:21:32 发布

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本文介绍了一个使用Socket在局域网内实现通信的示例。该示例包括服务端与客户端的代码实现，演示了一对一的通信过程。通过创建监听事件、接收事件等操作实现了消息的收发。

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本例采用Socket实现局域网通信。

开发环境：XP+VS2005+MFC

关键API：WSACreateEvent、WSAEventSelect、WSACloseEvent、WSAWaitForMultipleEvents、WSAEnumNetworkEvents。

参考：http://blog.youkuaiyun.com/mlite/article/details/699340。

示例程序：Win32程序，lib中依赖ws2_32.lib。简单模型，服务端与客户端一对一通话。

服务端代码

IMEventServer.cpp

// IMEventServer.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <WinSock2.h>
#include <stdio.h>
#include <stdlib.h>

const UINT DEFAULT_PORT = 5150;
const UINT DEFAULT_BUFFER = 4096;
const UINT LISTEN_LEN = 8;

//处理执行线程
void ExecThreadMng(SOCKET sAccept);
//Socket监听客户端消息线程
DWORD WINAPI SocketClientThread(LPVOID lpParam);
//服务端定时发送消息线程
DWORD WINAPI SocketSendThread(LPVOID lpParam);

WSAEVENT g_nAcceptEvent;
bool g_bAcceptClose = false;

int _tmain(int argc, _TCHAR* argv[])
{
    WSADATA wsd;
    if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)
    {
        printf("failed to load winsock!\n");
        return 1;
    }

    //Create our listening socket
    SOCKET sListen = socket(AF_INET, SOCK_STREAM, IPPROTO_IP);
    if (sListen == SOCKET_ERROR)
    {
        printf("socket() failed:%d\n", WSAGetLastError());
        return 1;
    }

    //Select the local interface, and bind to it
    struct sockaddr_in local;
    //INADDR_ANY是所有网卡地址
    local.sin_addr.s_addr = htonl(INADDR_ANY);
    local.sin_family = AF_INET;
    local.sin_port = htons(DEFAULT_PORT);

    //绑定监听网卡地址和端口
    if (bind(sListen, (struct sockaddr*)&local, sizeof(local)) == SOCKET_ERROR)
    {
        printf("bind() failed:%d\n", WSAGetLastError());
        return 1;
    }
    //开始监听客户端
    listen(sListen, LISTEN_LEN);

    printf("listening on port %d\n", DEFAULT_PORT);

    //简单模型，只接受一个客户端
    //进行一对一通话
    SOCKET sAccept = accept(sListen, NULL, NULL);
    printf("socket %d connected\n", sAccept);

    g_nAcceptEvent = WSACreateEvent();
    WSAEventSelect(sAccept, g_nAcceptEvent, FD_READ | FD_CLOSE);

    //创建执行线程
    ExecThreadMng(sAccept);
    
    closesocket(sListen);
    WSACleanup();

    system("pause");

	return 0;
}

void ExecThreadMng(SOCKET sAccept)
{
    HANDLE hClientThread = CreateThread(NULL, 0, SocketClientThread,
        (LPVOID)sAccept, 0, NULL);
    HANDLE hSendThread = CreateThread(NULL, 0, SocketSendThread,
        (LPVOID)sAccept, 0, NULL);

    if (    NULL == hClientThread
        || NULL == hSendThread)
    {
        printf("CreateThread() failed:%d\n", GetLastError());
        return;
    }

    HANDLE arrayWaitHandle[2];
    arrayWaitHandle[0] = hClientThread;
    arrayWaitHandle[1] = hSendThread;

    //等待线程执行完毕
    WaitForMultipleObjects(2, arrayWaitHandle, TRUE, INFINITE);

    CloseHandle(hClientThread);
    CloseHandle(hSendThread);
}

//Socket监听客户端消息线程
DWORD WINAPI SocketClientThread(LPVOID lpParam)
{
    SOCKET sAccept = (SOCKET)lpParam;

    while (true)
    {
        WSAEVENT arrayEvent[1];
        arrayEvent[0] = g_nAcceptEvent;

        DWORD nEventIndex = WSAWaitForMultipleEvents(1, arrayEvent,
            FALSE, WSA_INFINITE, FALSE);
        DWORD nArrayIndex = nEventIndex - WSA_WAIT_EVENT_0;

        WSANETWORKEVENTS networkEvents;
        WSAEnumNetworkEvents(sAccept, g_nAcceptEvent, &networkEvents);

        if (networkEvents.lNetworkEvents & FD_READ)
        {
            //获取客户端消息
            int nErrorCode = networkEvents.iErrorCode[FD_READ_BIT];
            if (nErrorCode != 0)
            {
                printf("FD_READ failed with error %d\n", nErrorCode);
                continue;
            }

            //Read data from the socket
            char szBuff[DEFAULT_BUFFER];

            int ret = recv(sAccept, szBuff, DEFAULT_BUFFER, 0);
            if (SOCKET_ERROR == ret)
            {
                printf("recv() failed\n");
                continue;
            }

            szBuff[ret] = '\0';
            printf("recv from client:%s\n", szBuff);
        }
        else if (networkEvents.lNetworkEvents & FD_CLOSE)
        {
            //客户端连接关闭
            g_bAcceptClose = true;

            int nErrorCode = networkEvents.iErrorCode[FD_CLOSE_BIT];
            if (nErrorCode != 0)
            {
                printf("FD_CLOSE failed with error %d\n", nErrorCode);
            }
            else
            {
                printf("FD_CLOSE success\n");
            }

            closesocket(sAccept);
            WSACloseEvent(g_nAcceptEvent);

            break;
        }
    }

    return 1;
}

//服务端定时呼叫客户端
DWORD WINAPI SocketSendThread(LPVOID lpParam)
{
    SOCKET sAccept = (SOCKET)lpParam;

    char szMessage[64] = {0};
    strcpy_s(szMessage, "server timing call");

    while (true)
    {
        Sleep(3000);

        if (g_bAcceptClose)
        {
            //连接断开，则退出
            break;
        }

        int nRet = send(sAccept, szMessage, (int)strlen(szMessage), 0);
        if (nRet == SOCKET_ERROR)
        {
            printf("send() failed:%d\n", WSAGetLastError());
        }
        else
        {
            printf("Server send:%s\n", szMessage);
        }
    }

    return 1;
}

客户端代码

IMEventClient.cpp

// IMEventClient.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <WinSock2.h>
#include <stdio.h>
#include <stdlib.h>

#define DEFAULT_PORT 5150
#define DEFAULT_BUFFER 4096

//处理执行线程
void ExecThreadMng(SOCKET sClient);
//客户端接受消息线程
DWORD WINAPI SocketRecvThread(LPVOID lpParam);
//客户端发送消息线程
DWORD WINAPI SocketSendThread(LPVOID lpParam);

//客户端响应事件
WSAEVENT g_nClientEvent;
bool g_bClientClose = false;

int _tmain(int argc, _TCHAR* argv[])
{
    WSADATA wsd;
    if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)
    {
        printf("failed to load Winsock!\n");
        return 1;
    }

    //Create the socket, and attempt to connect to the server
    SOCKET sClient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (sClient == INVALID_SOCKET)
    {
        printf("socket() failed:%d\n", WSAGetLastError());
        return 1;
    }

    struct sockaddr_in server;
    server.sin_family = AF_INET;
    server.sin_port = htons(DEFAULT_PORT);
    server.sin_addr.s_addr = inet_addr("127.0.0.1");

    if (connect(sClient, (struct sockaddr*)&server, sizeof(server))
        == SOCKET_ERROR)
    {
        printf("connect() failed:%d\n", WSAGetLastError());
        return 1;
    }
    printf("connect() success\n");

    g_nClientEvent = WSACreateEvent();
    WSAEventSelect(sClient, g_nClientEvent, FD_READ | FD_CLOSE);

    ExecThreadMng(sClient);

    WSACleanup();

    system("pause");

	return 0;
}


void ExecThreadMng(SOCKET sClient)
{
    HANDLE hRecvThread = CreateThread(NULL, 0, SocketRecvThread,
        (LPVOID)sClient, 0, NULL);
    HANDLE hSendThread = CreateThread(NULL, 0, SocketSendThread,
        (LPVOID)sClient, 0, NULL);

    if (    NULL == hRecvThread
        || NULL == hSendThread)
    {
        printf("CreateThread() failed:%d\n", GetLastError());
        return;
    }

    HANDLE arrayWaitHandle[3];
    arrayWaitHandle[0] = hRecvThread;
    arrayWaitHandle[1] = hSendThread;

    //等待线程执行完毕
    WaitForMultipleObjects(2, arrayWaitHandle, TRUE, INFINITE);

    CloseHandle(hRecvThread);
    CloseHandle(hSendThread);
}

//客户端接受消息线程
DWORD WINAPI SocketRecvThread(LPVOID lpParam)
{
    SOCKET sClient = (SOCKET)lpParam;

    WSAEVENT arrayEvent[1];
    arrayEvent[0] = g_nClientEvent;

    while (true)
    {
        DWORD nEventIndex = WSAWaitForMultipleEvents(1, arrayEvent,
            FALSE, WSA_INFINITE, FALSE);
        DWORD nArrayIndex = nEventIndex - WSA_WAIT_EVENT_0;

        WSANETWORKEVENTS networkEvents;
        WSAEnumNetworkEvents(sClient, g_nClientEvent, &networkEvents);

        if (networkEvents.lNetworkEvents & FD_READ)
        {
            //获取客户端消息
            int nErrorCode = networkEvents.iErrorCode[FD_READ_BIT];
            if (nErrorCode != 0)
            {
                printf("FD_READ failed with error %d\n", nErrorCode);
                break;
            }

            if (!g_bClientClose)
            {
                //Read data from the socket
                char szBuff[DEFAULT_BUFFER];

                int ret = recv(sClient, szBuff, DEFAULT_BUFFER, 0);
                if (SOCKET_ERROR == ret)
                {
                    printf("recv() failed\n");
                }
                else
                {
                    szBuff[ret] = '\0';
                    printf("recv from server:%s\n", szBuff);
                }
            }
            else
            {
                printf("FD_READ quit\n");
                break;
            }
        }
        else if (networkEvents.lNetworkEvents & FD_CLOSE)
        {
            //客户端连接关闭
            int nErrorCode = networkEvents.iErrorCode[FD_CLOSE_BIT];
            if (nErrorCode != 0)
            {
                printf("FD_CLOSE failed with error %d\n", nErrorCode);
            }

            printf("FD_CLOSE close socket\n");

            break;
        }
        else
        {
            printf("FD_NULL quit\n");

            break;
        }
    }

    return 1;
}

//客户端每3秒钟，定时发消息到服务端
DWORD WINAPI SocketSendThread(LPVOID lpParam)
{
    SOCKET sClient = (SOCKET)lpParam;
    char szMessage[64] = {0};
    strcpy_s(szMessage, "client timing call");

    //客户端发送3次则退出
    for (int i = 0; i < 3; i++)
    {
        Sleep(1000);

        int nRet = send(sClient, szMessage, (int)strlen(szMessage), 0);
        if (nRet == SOCKET_ERROR)
        {
            printf("send() failed:%d\n", WSAGetLastError());
        }
        else
        {
            printf("Client send:%s\n", szMessage);
        }
    }

    g_bClientClose = true;

    //关闭连接
    closesocket(sClient);
    //关闭事件
    WSACloseEvent(g_nClientEvent);

    return 1;
}