udp.cpp

基于ARM9(Wince)的网络音视频通信

// UDP_CE.cpp: implementation of the CUDP_CE class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "UDP.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CUDP_CE::CUDP_CE()
{
	
}

CUDP_CE::~CUDP_CE()
{
	
}


/*
*函数介绍：打开UDP通讯端口
*入口参数：pWnd: 指定父窗体指针 
           localPort: 指定远程UDP端口
           romoteHost:指定远程IP地址
           remotePort:指定远程UDP端口
*出口参数：(无)
*返回值：1代表成功；-1，-2，-3等都代表失败
*/
DWORD CUDP_CE::Open(CWnd* pWnd,int localPort,LPCTSTR remoteHost,int remotePort)
{
	
	WSADATA wsa;
	
	m_pOwnerWnd = pWnd;
	
	//加载winsock动态链接库
	if (WSAStartup(MAKEWORD(1,1),&wsa) != 0)
	{
		return -1;//代表失败
	}
	
	//创建UDP套接字
	m_UDPSocket = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
	if (m_UDPSocket == INVALID_SOCKET)
	{
		return -2;
	}
	
	SOCKADDR_IN localAddr;
	localAddr.sin_family = AF_INET;
	localAddr.sin_port = htons(localPort);
	localAddr.sin_addr.s_addr=INADDR_ANY;
	
	//绑定地址
	if(bind(m_UDPSocket,(sockaddr*)&localAddr,sizeof(localAddr))!=0)
	{
		return -3;
	}
	
	
	//设置非堵塞通讯
	DWORD ul= 1;
	ioctlsocket(m_UDPSocket,FIONBIO,&ul);

	//创建一个线程退出事件
	m_ExitThreadEvent	= CreateEvent(NULL,TRUE,FALSE,NULL);
	
	//创建通讯线程
	AfxBeginThread(RecvThread,this);
	
	m_RemoteAddr.sin_family = AF_INET;
	m_RemoteAddr.sin_port = htons(remotePort);
	//此处要将双字节转换成单字节
	char ansiRemoteHost[255];
	ZeroMemory(ansiRemoteHost,255);
	WideCharToMultiByte(CP_ACP,WC_COMPOSITECHECK,remoteHost,wcslen(remoteHost)
		,ansiRemoteHost,wcslen(remoteHost),NULL,NULL);
	m_RemoteAddr.sin_addr.s_addr=inet_addr(ansiRemoteHost);
	return 1;
}

/*
*函数介绍：关闭UDP通讯端口
*入口参数：(无)
*出口参数：(无)
*返 回 值：1代表成功；-1，-2等都代表失败
*/
DWORD CUDP_CE::Close(void)
{
	//设置通讯线程退出事件，通知线程退出
	SetEvent(m_ExitThreadEvent);
	Sleep(2000);
	//关闭线程句柄
	CloseHandle(m_ExitThreadEvent);
	//关闭socket
	if (closesocket(m_UDPSocket) == SOCKET_ERROR)
	{
		return -1;
	}
	
	//释放socket资源
	if (WSACleanup() == SOCKET_ERROR)
	{
		return -2;
	}
	return 1;
}

/*
*函数介绍：发送数据
*入口参数：dataPriority: 数据优先级 
           dataType: 数据类型
           buf:缓冲区数据
           len:缓冲数据长度
*出口参数：(无)
*返回值：发送成功代表实际发送的字节数，否则返回-1
*/
bool CUDP_CE::SendData(const char *buf, int len)
{
	int nBytes = 0;
	int nErrorCode;
	nBytes = sendto(m_UDPSocket,buf,len,0,(sockaddr*)&m_RemoteAddr,sizeof(m_RemoteAddr));		

	return true;
}


/*
*函数介绍：接收线程函数
*入口参数：lparam : 指传进线程的参数
*出口参数：(无)
*返 回 值：无意义。
*/

#define recv_size 1024*20//如果是WIN32，大

#if defined(_WIN32_WCE)//如果是WINCE
#define recv_size 1024//小
#endif

UINT CUDP_CE::RecvThread(LPVOID lparam)
{
	CUDP_CE *pSocket;
	pSocket = (CUDP_CE*)lparam;
	fd_set fdRead;
	int ret;
	TIMEVAL	aTime;
	char * recvBuf=NULL;
	aTime.tv_sec = 1;
	aTime.tv_usec = 0;
	SOCKADDR_IN tmpAddr;
	int tmpRecvLen;
	int recvLen;
	unsigned long recvBufLen;
	int iErrorCode;
	
	char * recvedBuf = NULL;
	int recvedBufLen;

	while (TRUE)
	{		
        //收到退出事件，结束线程
		if (WaitForSingleObject(pSocket->m_ExitThreadEvent,0) == WAIT_OBJECT_0)
		{
			break;
		}

		//将set初始化空集合
		FD_ZERO(&fdRead);
		
		//将pSocket->m_UDPSocket套接字添加到集合中
		FD_SET(pSocket->m_UDPSocket,&fdRead);
		
		//调用select函数，判断套接字I/O状态
		ret = select(0,&fdRead,NULL,NULL,&aTime);
		
		if (ret == SOCKET_ERROR)
			break;

		if (ret > 0)
		{
			if (FD_ISSET(pSocket->m_UDPSocket,&fdRead))
			{
                tmpAddr.sin_family=AF_INET;             
                tmpAddr.sin_port = htons(pSocket->m_RemoteAddr.sin_port);
				tmpAddr.sin_addr.s_addr =INADDR_ANY;
                tmpRecvLen = sizeof(tmpAddr);
				
				ioctlsocket(pSocket->m_UDPSocket,FIONREAD,&recvBufLen);
				if (recvBufLen <= 0)
					return 0;

				recvBuf = new char[recv_size];
				recvedBuf = new char[recv_size];
				ZeroMemory(recvBuf,recv_size);
				ZeroMemory(recvedBuf,recv_size);

				recvLen = recvfrom(pSocket->m_UDPSocket,recvBuf, (int)recvBufLen,0,(SOCKADDR*)&tmpAddr,&tmpRecvLen);

				
/*				if (recvLen == SOCKET_ERROR)//即使recvLen = SOCKET_ERROR，但收到的数据依然有效
					break;
				
				else if (recvLen == 0)
					break;
				 
				else
				{
*/				//此处添加解析程序，将接收到的数据解析后，



					//测试收到的数据大小
				if(recvBufLen>1)
					pSocket->m_OnUdpRecv(pSocket->m_pOwnerWnd,recvBuf,recvBufLen,(SOCKADDR*)&tmpAddr);
				delete []recvBuf;
				recvBuf = NULL;
				delete []recvedBuf;
				recvedBuf = NULL;
				//}

				recvBufLen = 0;
				ioctlsocket(pSocket->m_UDPSocket,FIONREAD,&recvBufLen);
				
			}
		}
	}
	return 0;
}