SOCKET编程之WSAEventSelect模型

最新推荐文章于 2024-05-14 19:58:35 发布

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本文介绍如何使用WSAEventSelect模型实现一个简单的Echo服务端程序。该模型适用于Windows平台，通过等待多个事件来处理网络连接和数据收发。文章提供了完整的代码示例，演示了从初始化套接字到接收和发送数据的过程。

今天又琢磨了一下WSAEventSelect模型：跟WSAAsyncSelect比起来，不用跟窗口消息挂钩，当然适用面就更广了，还是不错的，里面需要用到的新的东西有，全大写的是结构体，否则是函数：
WSAEventSelect
WSAWaitForMultipleEvents
WSAEVENT
WSANETWORKEVENTS
WSAEnumNetworkEvents
WSACreateEvent
下面是根据这个写的一个echo服务端

//Author:mungco
#include <winsock2.h>
#include <windows.h>
#include <stdio.h>

#define PORT 8888
#define DATA_BUFSIZE 1024

SOCKET Socket[WSA_MAXIMUM_WAIT_EVENTS];
WSAEVENT Event[WSA_MAXIMUM_WAIT_EVENTS];
DWORD EventTotal = 0;
DWORD Index;

void InitSocket()
{
    WSADATA wsaData;
    int ret;
    if((ret=WSAStartup(MAKEWORD(2,2),&wsaData))!=0){
        printf("WSAStartup failed with error:%d\n",ret);
        WSACleanup();
        return;
    }
}


int main(int argc , char *argv[])
{
    InitSocket();
    SOCKET ListenSocket,AcceptSocket;
    SOCKADDR_IN InternetAddr;
    DWORD Flags;
    DWORD ThreadId;
    DWORD RecvBytes;
    int Ret;
    char buffer[DATA_BUFSIZE];
    char sendbuffer[]="Your message has been received by server!";
    int AddrSize=sizeof(SOCKADDR);
    if((ListenSocket=WSASocket(AF_INET,SOCK_STREAM,0,NULL,0,WSA_FLAG_OVERLAPPED))==INVALID_SOCKET){
        printf("Failed to get a socket %d\n",WSAGetLastError());
        return 1;
    }
    
    InternetAddr.sin_family=AF_INET;
    InternetAddr.sin_addr.s_addr=htons(INADDR_ANY);
    InternetAddr.sin_port=htons(PORT);
    
    if(bind(ListenSocket,(SOCKADDR*)&InternetAddr,AddrSize)==SOCKET_ERROR){
        printf("bind Error:%d\n",WSAGetLastError());
        return 1;
    }
    
    WSAEVENT NewEvent=WSACreateEvent();
    WSAEventSelect(ListenSocket,NewEvent,FD_ACCEPT|FD_CLOSE);
    
    if(listen(ListenSocket,5)==SOCKET_ERROR){
        printf("listen failed with error:%d\n",WSAGetLastError());
        return 1;
    }
    
    Socket[EventTotal]=ListenSocket;
    Event[EventTotal]=NewEvent;
    EventTotal++;
    
    //Setup the listening socket for connections.
    for(;;){
        Index=WSAWaitForMultipleEvents(EventTotal,Event,FALSE,WSA_INFINITE,FALSE);
        WSANETWORKEVENTS NetworkEvents;
        WSAEnumNetworkEvents(Socket[Index-WSA_WAIT_EVENT_0],Event[Index-WSA_WAIT_EVENT_0],&NetworkEvents);
        if(NetworkEvents.lNetworkEvents & FD_ACCEPT){
            if(NetworkEvents.iErrorCode[FD_ACCEPT_BIT]!=0){
                printf("FD_ACCEPT failed with error :%d\n",NetworkEvents.iErrorCode[FD_ACCEPT_BIT]);
                break;
            }
            if((AcceptSocket=accept(Socket[Index-WSA_WAIT_EVENT_0],NULL,NULL))==SOCKET_ERROR){
                printf("Socket Error:%d\n",WSAGetLastError());
                break;
            }
            if(EventTotal>WSA_MAXIMUM_WAIT_EVENTS){
                printf("Too many connections");
                return 1;
            }
            NewEvent = WSACreateEvent();
            WSAEventSelect(AcceptSocket,NewEvent,FD_READ|FD_WRITE|FD_CLOSE);
            
            Event[EventTotal]=NewEvent;
            Socket[EventTotal]=AcceptSocket;
            EventTotal++;
            printf("Socket %d connected\n",AcceptSocket);
        }
        if(NetworkEvents.lNetworkEvents & FD_READ){
            if(NetworkEvents.iErrorCode[FD_READ_BIT]!=0){
                printf("FD_READ failed with error %d\n",NetworkEvents.iErrorCode[FD_READ_BIT]);
                break;
            }
            int count=recv(Socket[Index-WSA_WAIT_EVENT_0],buffer,sizeof(buffer),0);
            if(count==0){
                printf("Socket disconnected\n");
                break;
            }
            else if(count<0){
                printf("recv failed with error:%d\n",WSAGetLastError());
                break;
            }
            else{
                buffer[count]='\0';
                printf("%d:%s\n",Socket[Index-WSA_WAIT_EVENT_0],buffer);
                send(Socket[Index-WSA_WAIT_EVENT_0],sendbuffer,strlen(sendbuffer)+1,0);
            }
        }
        if(NetworkEvents.lNetworkEvents & FD_WRITE){
            if(NetworkEvents.iErrorCode[FD_WRITE_BIT]!=0){
                printf("FD_WRITE failed with error %d\n",NetworkEvents.iErrorCode[FD_WRITE_BIT]);
                break;
            }
            printf("Why should I write!\n");
//            buffer[0]='\0'; 
//            send(Socket[Index-WSA_WAIT_EVENT_0],buffer,strlen(buffer),0);
        }
        if(NetworkEvents.lNetworkEvents & FD_CLOSE){
            if(NetworkEvents.iErrorCode[FD_CLOSE_BIT]!=0){
                printf("FD_CLOSE failed with error %d\n",NetworkEvents.iErrorCode[FD_CLOSE_BIT]);
                break;
            }
            closesocket(Socket[Index-WSA_WAIT_EVENT_0]);
            Socket[Index-WSA_WAIT_EVENT_0]=Socket[--EventTotal];
        }
    }    
}