非阻塞 TCP协议下多用户的服务器

// 一个监听线程， 每当一个新的客户端连接进来时会再创建一个新的线程供连接

#include "stdafx.h"

#include <winsock2.h>

#include <iostream>

#pragma comment( lib, "ws2_32.lib" )

const static int BUF_SIZE = 256;

using namespace std;

#define MAIN_RETURN_ERROR   -1;

#define MAIN_RETURN_NORMAL  0;

DWORD WINAPI AnswerThread( LPVOID lparam );

sockaddr_in addrClient;

int addrClientLen = sizeof( addrClient );

int _tmain( int argc , _TCHAR* argv[])

{

      // 初始化Winsock 2.2

      WSADATA wsaData ;

      if( WSAStartup ( MAKEWORD( 2, 2 ), & wsaData ) != 0 )

     {

           cout<<"WSAStartup 无法初始化 !" <<endl ;

           return MAIN_RETURN_ERROR ;

     }

      // 通过WinSock 实现网络通信

      SOCKET sServer ;

    // 创建用于监听的Socket

      sServer = socket ( AF_INET, SOCK_STREAM, IPPROTO_TCP );

      if( INVALID_SOCKET == sServer )

     {

           cout<<"Socket Failed !" <<endl;

           WSACleanup();

           return MAIN_RETURN_ERROR ;

     }

      // 设置服务器Socket 地址

      SOCKADDR_IN addrServ ;

      addrServ.sin_family   = AF_INET;

      addrServ.sin_port     = htons( 9990 );   // 服务器端口号

      addrServ.sin_addr .S_un. S_addr = htonl ( INADDR_ANY );

      // 绑定

      int    retVal ;

      retVal = bind ( sServer, ( const struct sockaddr *)&addrServ , sizeof( SOCKADDR_IN ) );

      if( SOCKET_ERROR == retVal )

     {

           cout<<"bind failed !" <<endl;

           closesocket( sServer );

           WSACleanup();

           return -1;

     }

      // 监听

      retVal = listen ( sServer, 1 );

      if( SOCKET_ERROR == retVal )

     {

           cout<<"listen failed !" <<endl;

           closesocket( sServer );

           WSACleanup();

           return -1;

     }

      // 设置socket 其为非阻塞模式 , argp 设为非零值

      int iModel = 1; 

      retVal = ioctlsocket ( sServer, FIONBIO, (u_long FAR* )&iModel );

      if( SOCKET_ERROR == retVal )

     {

           cout<<"ioctlsocket failed " <<endl;

           WSACleanup();

           return MAIN_RETURN_ERROR ;

     }

      cout<<"TCP Server Start ... ..." <<endl;

      // 循环等待

      while( true )

     {

           SOCKET sClient = accept( sServer, ( sockaddr FAR*)&addrClient , &addrClientLen );

           if( INVALID_SOCKET == sClient )

          {

               int err = WSAGetLastError();

               if( WSAEWOULDBLOCK == err )  // 没接到连接请求

              {

                    Sleep( 100 );

                    continue;

              }

               else

              {

                    cout<<"accept failed" <<endl;

                    closesocket( sServer );

                    WSACleanup();

                    return MAIN_RETURN_ERROR ;

              }

          }

          // 接到了创建一个新线程供新的客户端使用

           DWORD dwThreadId ;

           CreateThread( NULL , NULL, AnswerThread, (LPVOID )sClient, 0, & dwThreadId );

     }

      // 最后做一些清理工作

      closesocket( sServer );

      WSACleanup();

      system("pause" );

      return MAIN_RETURN_NORMAL ;

}

DWORD WINAPI AnswerThread( LPVOID lparam )

{

      // 循环接受客户端发送来的请求，直到客户端发送 quit 命令

      char buf [BUF_SIZE];

      int  retVal ;

      SOCKET sClient = (SOCKET)( LPVOID)lparam ;

      while( true )

     {

           ZeroMemory( buf , BUF_SIZE );

           retVal = recv ( sClient, buf, BUF_SIZE , 0 );

           if( SOCKET_ERROR == retVal )

          {

               int err = WSAGetLastError();

               if( WSAEWOULDBLOCK == err )

              {

                    Sleep( 100 );

                    continue;

              }

               else if ( WSAETIMEDOUT == err || WSAENETDOWN == err )   // 网络系统故障

              {

                    cout<<"recv failed !" <<endl;

                    closesocket( sClient );

                    WSACleanup();

                    return MAIN_RETURN_ERROR ;

              }

          }

           SYSTEMTIME st ;

           GetLocalTime( &st );

           char sDateTime [30];

           sprintf( sDateTime , "%4d-%2d-%2d %2d:%2d:%2d", st.wYear , st. wMonth, st .wDay, st.wHour , st. wMinute, st.wSecond );

           cout<<sDateTime <<"  , Recv From Client [ "<< inet_ntoa( addrClient .sin_addr )<<":" <<addrClient. sin_port<<"]: " <<buf<< endl;

           if( 0 == strcmp ( buf, "quit" ) )

          {

               retVal = send ( sClient, "quit", strlen ("quit"), 0 );

               break;

          }

           else

          {

               char msg [BUF_SIZE];

               sprintf( msg , "Message receive - %s ", buf );

               while( true )

              {

                    retVal = send ( sClient, msg, strlen ( msg ), 0 );

                    if( SOCKET_ERROR == retVal )

                   {

                         int err = WSAGetLastError();

                         if( WSAEWOULDBLOCK == err )

                        {

                              Sleep( 100 );

                              continue;

                        }

                         else

                        {

                              cout<<"send failed !" <<endl;

                              closesocket( sClient );

                              WSACleanup();

                              return MAIN_RETURN_ERROR ;

                        }

                   }

                    else

                         break;

              }

          }

     }

      closesocket( sClient );

}