之一 select模型

// select.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <WinSock2.h>
#include <Windows.h>
#include <iostream>
#pragma comment(lib,"ws2_32.lib")

int _tmain(int argc, _TCHAR* argv[])
{
    WORD wVersion = MAKEWORD(2,2);
    WSADATA wsaData = {0};
    if(WSAStartup(wVersion,&wsaData)!=0)
    {
        printf("Inin WSAStartup Error\r\n");
        return -1;
    }

    SOCKET ListenSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
    if(ListenSocket==INVALID_SOCKET)
    {
        WSACleanup();
        printf("Create Socket Error\r\n");
        return -1;
    }
    sockaddr_in LocalAddress;
    LocalAddress.sin_family = AF_INET;
    LocalAddress.sin_port = htons(9627);
    LocalAddress.sin_addr.S_un.S_addr = INADDR_ANY;

    if(bind(ListenSocket,(sockaddr*)&LocalAddress,sizeof(LocalAddress))==SOCKET_ERROR)
    {
        closesocket(ListenSocket);
        WSACleanup();
        printf("Failed bind()\r\n");
        return -1;
    }
    listen(ListenSocket,5);

    fd_set fdSocket;
    FD_ZERO(&fdSocket);
    FD_SET(ListenSocket,&fdSocket);
    while(true)
    {
        fd_set fdRead = fdSocket;
        int iPending = select(0,&fdRead,NULL,NULL,NULL);
        if(iPending>0)
        {
            for(int i=0;i<(int)fdSocket.fd_count;i++)
            {
                if(FD_ISSET(fdSocket.fd_array[i],&fdRead))
                {
                    if(fdSocket.fd_array[i]==ListenSocket) //什么时候不相等，即能跳到下一个else
                    {
                        if(fdSocket.fd_count<FD_SETSIZE)
                        {
                            sockaddr_in addrRemote;
                            int nAddrLen = sizeof(addrRemote);
                            SOCKET sNew = accept(ListenSocket,(sockaddr*)&addrRemote,&nAddrLen);
                            FD_SET(ListenSocket,&fdSocket);
                            printf("接收到链接：%s\n",inet_ntoa(addrRemote.sin_addr));
                        }
                        else
                        {
                            printf("Too much connections!\n");
                            continue;
                        }
                    }
                    else
                    {
                        char szBufferData[0x1000];
                        int iReturn = recv(fdSocket.fd_array[i],szBufferData,0x1000,0);
                        if(iReturn > 0)
                        {
                            szBufferData[iReturn] = ‘\0‘;
                            printf("接受信息:%s\n", szBufferData);
                        }
                        else
                        {
                            closesocket(fdSocket.fd_array[i]);
                            FD_CLR(fdSocket.fd_array[i],&fdSocket);
                        }
                    }
                }
            }
        }
    }
    return 0;
}