select函数用法有关问题！1

select函数用法问题！！！！1
这段测试代码是服务器端的代码，

问题描述：当客户端进行连接的时候，连接成功，只能发送一次数据，第二次发送的数据服务器端接受不到，而且select函数也检测不到客户端发送数据到来。
请大家帮忙找下原因，偶是菜鸟。。。

C/C++ code

#include <iostream>#include <Windows.h>#include <WinSock.h>#include <time.h>using namespace std;#pragma warning (disable:4996)#pragma comment (lib,"ws2_32.lib")#define PORT        4000#define IP_ADDRESS  "127.0.0.1"int main(){    WSADATA Ws;    int    Ret = 0;    int    AddrLen = 0;    HANDLE hThread = NULL;    char   RecvBuffer[256] = {0};    SOCKET ServerSocket, ClientSocket;    struct sockaddr_in LocalAddr, ClientAddr;    fd_set  fdread;    fd_set  fdwrite;    timeval tv;    int     select_result;    if(WSAStartup(MAKEWORD(2,2), &Ws) != 0)    {        cout<<"Init windows socket failed"<<GetLastError()<<endl;        return -1;    }    ServerSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);    if(ServerSocket == INVALID_SOCKET)    {        cout<<"Create socket failed"<<endl;        return -1;    }    LocalAddr.sin_family            = AF_INET;    LocalAddr.sin_addr.S_un.S_addr    = inet_addr(IP_ADDRESS);    LocalAddr.sin_port                = htons(PORT);    memset(LocalAddr.sin_zero, 0x00, 8);    Ret = bind(ServerSocket, (struct sockaddr*)&LocalAddr, sizeof(LocalAddr));    if(Ret != 0)    {        cout<<"Bind socket failed"<<endl;        return -1;    }    Ret = listen(ServerSocket, 10);    if(Ret != 0)    {        cout<<"listen socket failed"<<endl;        return -1;    }    cout<<"server start...."<<endl;    while(1)    {        FD_ZERO(&fdread);        FD_ZERO(&fdwrite);        FD_SET(ServerSocket, &fdread);        FD_SET(ServerSocket, &fdwrite);        tv.tv_sec = 10;        tv.tv_usec = 0;        cout<<"select start"<<endl;        select_result = select(0, &fdread, &fdwrite, NULL, &tv);            AddrLen = sizeof(ClientAddr);        if(select_result > 0)        {            cout<<"select result == "<<select_result<<endl;            for(int i = 0; i < (int)fdread.fd_count; i++)            {                cout<<" i == "<<i<<endl;                if(FD_ISSET(fdread.fd_array[i], &fdread))                {                    ClientSocket                         = accept(fdread.fd_array[i],                         (struct sockaddr*)&ClientAddr, &AddrLen);                    cout<<"Connected from "                        <<inet_ntoa(ClientAddr.sin_addr)<<endl;                    Ret = recv(ClientSocket, RecvBuffer, 256, 0);                    if(Ret == 0 || Ret == SOCKET_ERROR)                    {                        cout<<"client quit"<<endl;                    }                            cout<<"Recv Msg is:    "<<RecvBuffer<<endl;                    memset(RecvBuffer, 0, 256);                }                else                {                    Ret = recv(fdread.fd_array[i], RecvBuffer, 256, 0);                    if(Ret > 0)                    {                        cout<<"Recv msg    "<<RecvBuffer<<endl;                    }                    else                    {                        closesocket(fdread.fd_array[i]);                        cout<<"close one client"<<endl;                        FD_CLR(fdread.fd_array[i], &fdread);                    }                }            }        }    }    closesocket(ServerSocket);    closesocket(ClientSocket);    WSACleanup();    return 0;}

FD_ZERO(&fdread);
FD_ZERO(&fdwrite);
FD_SET(ServerSocket, &fdread);
FD_SET(ServerSocket, &fdwrite);

你永远只监听SERVERSOCKET, 不监听客户端了?

select_result = select(0, &fdread, &fdwrite, NULL, &tv);


int select(int nfds, fd_set *readfds, fd_set *writefds,
fd_set *exceptfds, struct timeval *timeout);

第一个参数是maxfd + 1， 你一直用0根本就不检测，而且你每次都设置read集合里有监听套接字，
if(FD_ISSET(fdread.fd_array[i], &fdread))
{
这段代码将会永远成立，因为你select根本就没执行。

我说的是linux，windows接口是否有小差别不知道。