关于数据包接收多次的原因（困扰我很久了）

zzyoucan 2013-01-24 11:25:53

使用MFC的CAsyncSocket建立的socket，使用UDP请求数据，但出现下面的情况
假如CMD_UDP_REQUEST_ADIONETWORK_ALL命令的数据我只请求了一次，但是相对应命令为CMD_UDP_REQUEST_CHECK_RADIONETWORK_ALL的相同数据却发给了我多次，这样程序就出错了，对方就发了一次，我这边pc设置了几个ip就会接收到几次，
由于都是重复的，这样程序接收数据的速度变慢了，因为每次都要sleep一下
代码是这样的



UINT recv_netset_thread(LPVOID lParam)

{

       CNetSet *pNetset = (CNetSet *)lParam ;

	CString m_transmac ;

	char header[32] ;

	unsigned char pMac[100] ;

	BOOL b ;

	char buf[1500] ;

	int m_control ;

	m_transmac = CPublic::markmac ;

	UINT uni = PROTOCOLHEAD_VER;

	memcpy(header,&uni,4);

	sscanf(m_transmac.GetBuffer(),"%2x%2x%2x%2x%2x%2x",pMac,pMac+1,pMac+2,pMac+3,pMac+4,pMac+5);

	memcpy(header+4,pMac,6);//目的mac地址

	memcpy(header+10,CPublic::g_ucLocalMac,6);//原mac地址

	memcpy(header+16,"temp",4);//会话标示

	uni = 0x80000000 ;

	memcpy(header+20, &uni ,4);//数据包编号

	uni = CMD_UDP_REQUEST_CHECK_RADIONETWORK_ALL ;

	memcpy(header+24,&uni,4);//cmd

	uni = 0 ;//长度为0

	memcpy(header+28,&uni,4);//数据包长度

	CAsyncSocket CbroadcastSocket;

	if(CbroadcastSocket.Create(0,SOCK_DGRAM) == SOCKET_ERROR)

	{

		TRACE("fail to create socket\n");

		return -1;

	}

	b = TRUE;

	if(!CbroadcastSocket.SetSockOpt(SO_BROADCAST,&b,sizeof(b),SOL_SOCKET))

	{

		TRACE("fail to SetSockOpt\n");

		CbroadcastSocket.Close();

		return -1;

	}

	int nOpt = 1000;

	if(!CbroadcastSocket.SetSockOpt(SO_RCVTIMEO,(char *)&nOpt,sizeof(int),SOL_SOCKET))

	{

		TRACE("fail to SetSockOpt\n");

		CbroadcastSocket.Close();

		return -1;

	}

	b = true;

	if(!CbroadcastSocket.SetSockOpt(SO_REUSEADDR,(char *)&b,sizeof(BOOL),SOL_SOCKET))

	{

		TRACE("fail to SetSockOpt\n");

		CbroadcastSocket.Close();

		return -1;

	}

	//通过UDP发送

	int done = CbroadcastSocket.SendTo((string(header,32)).c_str(),32,PORT_UDP_PU,NULL,0);

	TRACE("done = %d to config pu net through UDP\n",done);

	if(done < 0)

	{

		AfxMessageBox("fail to send broadcast to config pu net\n");

		CbroadcastSocket.Close();

		return -1;

	}



	DWORD dwTick1 = ::GetTickCount() ;	

	while ( WaitForSingleObject(CPublic::m_event,100) != WAIT_OBJECT_0)

	{

		DWORD dwNow1 = ::GetTickCount() ;

		if (dwNow1 - dwTick1 > 15000)//大于15秒表示接收超时

			break ;

		Sleep(100) ;

		done = CbroadcastSocket.ReceiveFrom(buf,1500,NULL,0);//将数据接收在buf中

		if (done < 0)

			continue ;

		m_control = *(int *)(buf + 24) ;

		if (CMD_UDP_ANSWER_CHECK_RADIONETWORK_ALL == m_control)

		{

           //xp这里面的数据会接收到多次

                 }

          。。。

          }