C++ TCPSocket::Set方法代码示例

Task* CRTConnListener::GetSessionTask(int osSocket, struct sockaddr_in* addr)
{
    TCPSocket* theSocket = NULL;
    Assert(osSocket != EventContext::kInvalidFileDesc);

    // when the server is behing a round robin DNS, the client needs to knwo the IP address ot the server
    // so that it can direct the "POST" half of the connection to the same machine when tunnelling RTSP thru HTTP

    CRTConnection* theTask = new CRTConnection();
    if(NULL == theTask)
        return NULL;
    theSocket = theTask->GetSocket();  // out socket is not attached to a unix socket yet.

    //set options on the socket
    int sndBufSize = 96L * 1024L;
    theSocket->Set(osSocket, addr);
    theSocket->InitNonBlocking(osSocket);
    //we are a server, always disable nagle algorithm
    theSocket->NoDelay();
    theSocket->KeepAlive();
    theSocket->SetSocketBufSize(sndBufSize);
    //setup the socket. When there is data on the socket,
    //theTask will get an kReadEvent event
    theSocket->RequestEvent(EV_RE);
    theTask->SetTimer(30*1000);

    StrPtrLen* remoteStr = theSocket->GetRemoteAddrStr();
    LI("CRTConnListener Get a connection,ip:%.*s port:%d \n",remoteStr->Len, remoteStr->Ptr, ntohs(addr->sin_port));

    this->RunNormal();

    return theTask;
}

//acceptor模块调用GetSessionTask函数，创建一个连接会话，处理该socket句柄上的所有任务。
Task*   ApsAppTcpListenerSocket::GetSessionTask(int osSocket, struct sockaddr_in* addr)
{
	Assert(osSocket != EventContext::kInvalidFileDesc);
 	TCPSocket* theSocket = NULL; 
	
	//new one web accept session
    ApsAppSrvSession* theTask = new ApsAppSrvSession();
	ApsLogger::Debug("New PushClientSession, socket fd = %d task = %p!",osSocket,theTask); 
	if(NULL == theTask)//no enough memory, TCPListenerSocket will close the socket!
	{
		ApsLogger::Debug("PushClientSession create error: no memory!"); 		
		return NULL;
	}
    theSocket = theTask->GetSocket();  // out socket is not attached to a unix socket yet.

	//set options on the socket
	int sndBufSize = 1000L * 1024L;
    theSocket->Set(osSocket, addr);
    theSocket->InitNonBlocking(osSocket);
	theSocket->NoDelay();
	theSocket->KeepAlive();
	theSocket->SetSocketBufSize(sndBufSize);
    theSocket->RequestEvent(EV_RE);

    this->RunNormal();
        
    return theTask;
}

void TCPSocket::SnarfSocket( TCPSocket & fromSocket )
{
    // take the connection away from the other socket
    // and use it as our own.
    Assert(fFileDesc == EventContext::kInvalidFileDesc);
    this->Set( fromSocket.fFileDesc, &fromSocket.fRemoteAddr );
    
    // clear the old socket so he doesn't close and the like
    struct  sockaddr_in  remoteaddr;
    
    ::memset( &remoteaddr, 0, sizeof( remoteaddr ) );

    fromSocket.Set( EventContext::kInvalidFileDesc, &remoteaddr );

    // get the event context too
    this->SnarfEventContext( fromSocket );

}

/* 利用入参的值配置本类TCPSocket各成员的信息,然后清空入参中的各成员值,类似于复制构造函数 */
void TCPSocket::SnarfSocket( TCPSocket & fromSocket )
{
    // take the connection away from the other socket
    // and use it as our own.
	/* 确保成员是初始状态 */
    Assert(fFileDesc == EventContext::kInvalidFileDesc);
	/* 利用入参设置Socket及调整其状态  */
    this->Set( fromSocket.fFileDesc, &fromSocket.fRemoteAddr );
    
    // clear the old socket so he doesn't close and the like
	/* 新建remoteaddr并零初始化,作下面fromSocket.Set()使用 */
    struct  sockaddr_in  remoteaddr;
    
    ::memset( &remoteaddr, 0, sizeof( remoteaddr ) );

	/* 清除入参的Socket信息 */
    fromSocket.Set( EventContext::kInvalidFileDesc, &remoteaddr );

    // get the event context too
	/* 利用EventContext::SnarfEventContext(), 利用入参来获取数据成员的值,并将数据成员fRef加入Hash Table中,删去入参中同key值的Ref  */
    this->SnarfEventContext( fromSocket );

}

void TCPListenerSocket::ProcessEvent(int /*eventBits*/)
{
    //we are executing on the same thread as every other
    //socket, so whatever you do here has to be fast.
    
    struct sockaddr_in addr;
#if __Win32__ || __osf__ || __sgi__ || __hpux__	
    int size = sizeof(addr);
#else
    socklen_t size = sizeof(addr);
#endif
    Task* theTask = NULL;
    TCPSocket* theSocket = NULL;
    
    //fSocket data member of TCPSocket.
	int osSocket = accept(fFileDesc, (struct sockaddr*)&addr, &size);

//test osSocket = -1;
	if (osSocket == -1)
	{
        //take a look at what this error is.
        int acceptError = OSThread::GetErrno();
        if (acceptError == EAGAIN)
        { 
            //If it's EAGAIN, there's nothing on the listen queue right now,
            //so modwatch and return
            this->RequestEvent(EV_RE);
            return;
        }
		
//test acceptError = ENFILE;
//test acceptError = EINTR;
//test acceptError = ENOENT;
		 
        //if these error gets returned, we're out of file desciptors, 
        //the server is going to be failing on sockets, logs, qtgroups and qtuser auth file accesses and movie files. The server is not functional.
		if (acceptError == EMFILE || acceptError == ENFILE)
        {           
#ifndef __Win32__

			QTSSModuleUtils::LogErrorStr(qtssFatalVerbosity,  "Out of File Descriptors. Set max connections lower and check for competing usage from other processes. Exiting.");
#endif

			exit (EXIT_FAILURE);	
        }
        else
        {   
            char errStr[256];
            errStr[sizeof(errStr) -1] = 0;
            qtss_snprintf(errStr, sizeof(errStr) -1, "accept error = %d '%s' on socket. Clean up and continue.", acceptError, strerror(acceptError)); 
            WarnV( (acceptError == 0), errStr);
            
            theTask = this->GetSessionTask(&theSocket);
            if (theTask == NULL)
            {   
                close(osSocket);
            }
            else
            {  
                theTask->Signal(Task::kKillEvent); // just clean up the task
            }
            
            if (theSocket)
                theSocket->fState &= ~kConnected; // turn off connected state
            
            return;
        }
	}
	
    theTask = this->GetSessionTask(&theSocket);
    if (theTask == NULL)
    {    //this should be a disconnect. do an ioctl call?
        close(osSocket);
        if (theSocket)
            theSocket->fState &= ~kConnected; // turn off connected state
    }
    else
    {   
        Assert(osSocket != EventContext::kInvalidFileDesc);
        
        //set options on the socket
        //we are a server, always disable nagle algorithm
        int one = 1;
        int err = ::setsockopt(osSocket, IPPROTO_TCP, TCP_NODELAY, (char*)&one, sizeof(int));
        AssertV(err == 0, OSThread::GetErrno());
        
        err = ::setsockopt(osSocket, SOL_SOCKET, SO_KEEPALIVE, (char*)&one, sizeof(int));
        AssertV(err == 0, OSThread::GetErrno());
    
        int sndBufSize = 96L * 1024L;
        err = ::setsockopt(osSocket, SOL_SOCKET, SO_SNDBUF, (char*)&sndBufSize, sizeof(int));
        AssertV(err == 0, OSThread::GetErrno());
    
        //setup the socket. When there is data on the socket,
        //theTask will get an kReadEvent event
        theSocket->Set(osSocket, &addr);
        theSocket->InitNonBlocking(osSocket);
        theSocket->SetTask(theTask);
        theSocket->RequestEvent(EV_RE);
        
//.........这里部分代码省略.........

/* 在TCPListenerSocket中,ProcessEvent 函数(继承EventContext 的ProcessEvent()函数)被重载用来创建Socket和Task 对象得配对 */
void TCPListenerSocket::ProcessEvent(int /*eventBits*/)
{
    //we are executing on the same thread as every other
    //socket, so whatever you do here has to be fast.
	/* 该函数运行于系统唯一的EventThread 线程中，所以要尽量快速，以免占用过多的系统资源 */

	/* 在accept()中存放接受的远处客户端的ip地址 */
    struct sockaddr_in addr;
    socklen_t size = sizeof(addr);


	/* 注意theTask(通过派生类TCPSocket)和theSocket都是TCPListenerSocket的基类 */
	/**************** 注意:通过子类重载GetSessionTask()使Task(具体说,是RTSPSession)和TCPSocket配对 ***********************/
    Task* theTask = NULL;
    TCPSocket* theSocket = NULL;
    
    //fSocket data member of TCPSocket.
	/* 服务器端的Socket接受客户端的Socket的连接请求,成功后返回服务器新建的接受连接的Socket的描述符,否则返回INVALID_SOCKET */
	int osSocket = accept(fFileDesc, (struct sockaddr*)&addr, &size);

//test osSocket = -1;
	/* 假如出错了,进行错误处理.以下全是错误处理!! */
	if (osSocket == -1)
	{
        //take a look at what this error is.
		/* 获取具体的出错原因 */
        int acceptError = OSThread::GetErrno();

		/* 对得出的错误分情形讨论: */

//test acceptError = EAGAIN;
        if (acceptError == EAGAIN)
        { 
            //If it's EAGAIN, there's nothing on the listen queue right now,
            //so modwatch and return
			/* 在同一socket端口上请求监听指定的EV_RE事件 */
            this->RequestEvent(EV_RE);
            return;
        }
		
//test acceptError = ENFILE;
//test acceptError = EINTR;
//test acceptError = ENOENT;
		 
        //if these error gets returned, we're out of file descriptors, 
        //the server is going to be failing on sockets, logs, qtgroups and qtuser auth file accesses and movie files. The server is not functional.
		// 文件描述符用光,这时服务器会丧失功能,直接退出
		if (acceptError == EMFILE || acceptError == ENFILE)
        {           
			QTSSModuleUtils::LogErrorStr(qtssFatalVerbosity,  "Out of File Descriptors. Set max connections lower and check for competing usage from other processes. Exiting.");
			exit (EXIT_FAILURE);	
        }
        else //假如是其它错误(除EAGAIN\EMFILE\ENFILE以外的),在屏幕上显示错误信息,同时将配对的任务和新建的TCPSocket分别删除和关闭,并返回 
        {   
            char errStr[256];
			/* 确保末尾null-terminated */
            errStr[sizeof(errStr) -1] = 0;
			/* 得到指定格式的errStr形如"accept error = 1 '*****error' on socket. Clean up and continue." */
            qtss_snprintf(errStr, sizeof(errStr) -1, "accept error = %d '%s' on socket. Clean up and continue.", acceptError, strerror(acceptError)); 
            /* 当条件不成立时,在屏幕上显示错误信息 */
			WarnV( (acceptError == 0), errStr);
            
			/**************** 注意:通过子类重载GetSessionTask()使Task和TCPSocket配对 ***********************/
			/* 用RTSPListenerSocket::GetSessionTask()获取Session Task和socket,并对结果分析 */
            theTask = this->GetSessionTask(&theSocket);
            if (theTask == NULL)
            {   
				/* 若没有获取任务,就关闭Socket */
                close(osSocket);
            }
            else
            {  
                theTask->Signal(Task::kKillEvent); // just clean up the task
            }
            
			/* 假如RTSPSession中相对应的theSocket非空,就将其状态设为非连接 */
            if (theSocket)
                theSocket->fState &= ~kConnected; // turn off connected state
            
            return;
        }
	}/* errors handling */
	
	/* 得到Session Task并作错误处理 */
	/* 注意以后的派生类(当是RTSPListenerSocket)去获取任务,并设置好Task和outSocket */
	/**************** 注意:通过子类重载GetSessionTask()使Task和TCPSocket配对 ***********************/
    theTask = this->GetSessionTask(&theSocket);
	/* 如果没有获得任务,将已接受连接的服务器端的osSocket关闭,将服务器上RTSPSession中相对应的theSocket关闭 */
    if (theTask == NULL)
    {    //this should be a disconnect. do an ioctl call?
        close(osSocket);
        if (theSocket)
            theSocket->fState &= ~kConnected; // turn off connected state
    }
	/* 假如成功获取到任务,就分别设置这相对应的两个Socket的相关属性 */
    else//创建Task成功,接着创建Socket 对象
    {   
		/* 确保接受连接的服务器端Socket不是初始状态 */
        Assert(osSocket != EventContext::kInvalidFileDesc);
//.........这里部分代码省略.........