readyRead problem

[fruzzo]

I've a problem with my client/server application...the strange behaviour is the following:
1. Connect client-server
2. Client send a message (msg#1) to server (time To) (this kind of message is sended to server every 5 seconds).
2. Server receive msg#1 istantly (To+a bit latency delay) and send to client a new message (msg#2) just after msg# is received (time T1).
2. Normally client must receive the msg#2 istantly T1 instead it receive msg#2 after 5 seconds, after client send the second time the msg#1.

It seem that something is locking the readyRaed signal and only when I send the second time the msg#1 it's unlocked.

Any idea about this problem?

You can find the source code in this 3D:
http://www.qtcentre.org/forum/f-qt-p...ate-22885.html

[wysota]

Do you have the event loop running in the thread where you handle the connection?

[fruzzo]

Do you have the event loop running in the thread where you handle the connection?

yes...infact I intercept other signal of my TcpRadio, except the readyRead signal or better...I intercept it with a delay of exactly 5 sec. respect what I want.

[wysota]

Do you use any waitFor...() methods?

[fruzzo]

Do you use any waitFor...() methods?

yes...when I send a message:

bool TcpConnection::sendMessage(const RadioMessageInterface* msg)
{
	QByteArray block;
	QDataStream out(&block, QIODevice::WriteOnly);
 
	int msgSize = 0;
	const char* data = msg->getData(msgSize);
 
	out<<(quint16)msgSize;
	out.writeRawData(data,msgSize);	
out.device()->seek(0);
out << quint16(block.size() - sizeof(quint16));
	int size = _socket->write(block); 
 
 
	if(size != block.size())
	{
		return false;
	}
 
	if(!_socket->waitForBytesWritten(_timeout))
		return false;
 
	return true;
}

bool TcpConnection::sendMessage(const RadioMessageInterface* msg)
{
	QByteArray block;
	QDataStream out(&block, QIODevice::WriteOnly);

	int msgSize = 0;
	const char* data = msg->getData(msgSize);

	out<<(quint16)msgSize;
	out.writeRawData(data,msgSize);	
out.device()->seek(0);
out << quint16(block.size() - sizeof(quint16));
	int size = _socket->write(block); 


	if(size != block.size())
	{
		return false;
	}

	if(!_socket->waitForBytesWritten(_timeout))
		return false;

	return true;
}

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[wysota]

yes...

Why? There is no point in doing that if you have an event loop running...

[fruzzo]

Why? There is no point in doing that if you have an event loop running...

mhmmm...strange because if I remove the waitForBytesWritten no messagegs are sended on the socket

[wysota]

Then you have no event loop running in your thread. Where do you call QThread::exec()?

[fruzzo]

Then you have no event loop running in your thread. Where do you call QThread::exec()?

This is the handler thread of the tcp radio:

//**********************************************************************************************************************************************
//Class TcpRadio Handler
//**********************************************************************************************************************************************
 
TcpRadioHandler::TcpRadioHandler(RADIO_MODE_TYPE mode, int localPort,const Node& remoteNode, RadioMessageInterfaceCreatorFunction messageCreator, int timeout, char * logDir)
:QThread(0), _tcpRadio(0),  _mode(mode), _localPort(localPort), _peerNode(remoteNode), _creator(messageCreator), _timeout(timeout)
{
	strcpy_s(_logDir, logDir);
	start();
}
 
TcpRadioHandler::~TcpRadioHandler()
{
	wait();
	if (_tcpRadio)
		delete _tcpRadio;
}
 
TcpRadio * TcpRadioHandler::radio()
{ 
	return _tcpRadio; 
}
 
void TcpRadioHandler::run()
{
	_tcpRadio = new TcpRadio(_mode, _localPort, _peerNode, _creator, _timeout, _logDir);
	exec();
}

//**********************************************************************************************************************************************
//Class TcpRadio Handler
//**********************************************************************************************************************************************

TcpRadioHandler::TcpRadioHandler(RADIO_MODE_TYPE mode, int localPort,const Node& remoteNode, RadioMessageInterfaceCreatorFunction messageCreator, int timeout, char * logDir)
:QThread(0), _tcpRadio(0),  _mode(mode), _localPort(localPort), _peerNode(remoteNode), _creator(messageCreator), _timeout(timeout)
{
	strcpy_s(_logDir, logDir);
	start();
}

TcpRadioHandler::~TcpRadioHandler()
{
	wait();
	if (_tcpRadio)
		delete _tcpRadio;
}

TcpRadio * TcpRadioHandler::radio()
{ 
	return _tcpRadio; 
}

void TcpRadioHandler::run()
{
	_tcpRadio = new TcpRadio(_mode, _localPort, _peerNode, _creator, _timeout, _logDir);
	exec();
}

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[wysota]

Where and how do you create the socket you use in TcpConnection::sendMessage?

[fruzzo]

Where and how do you create the socket you use in TcpConnection::sendMessage?

void TcpRadio::connectToPeer()
{
	if (_mode == SERVER)
		return;
	_peerNode.setConnection(TcpConnection::openOutcomingConnection(_peerNode.address(), _peerNode.port(), _creator, _timeout));
	const TcpConnection * conn = _peerNode.getConnection();
	connect(conn, SIGNAL(status(QString)), this, SIGNAL(updateStatus(QString)));
	connect(conn, SIGNAL(status(QString)), this, SLOT(writeLog(QString)));
	connect(conn, SIGNAL(readyRead()), this, SLOT(receive()));
	emit updateStatus("Opening connection with peer: " + _peerNode.address());
}
 
TcpConnection* TcpConnection::openOutcomingConnection(const QString& serverName, int port, RadioMessageInterfaceCreatorFunction messageCreator, int timeout)
{	
	QTcpSocket* socket = new QTcpSocket();
	socket->connectToHost(serverName, port, QIODevice::ReadWrite);	
	return new TcpConnection(socket, messageCreator, timeout);
}

void TcpRadio::connectToPeer()
{
	if (_mode == SERVER)
		return;
	_peerNode.setConnection(TcpConnection::openOutcomingConnection(_peerNode.address(), _peerNode.port(), _creator, _timeout));
	const TcpConnection * conn = _peerNode.getConnection();
	connect(conn, SIGNAL(status(QString)), this, SIGNAL(updateStatus(QString)));
	connect(conn, SIGNAL(status(QString)), this, SLOT(writeLog(QString)));
	connect(conn, SIGNAL(readyRead()), this, SLOT(receive()));
	emit updateStatus("Opening connection with peer: " + _peerNode.address());
}

TcpConnection* TcpConnection::openOutcomingConnection(const QString& serverName, int port, RadioMessageInterfaceCreatorFunction messageCreator, int timeout)
{	
	QTcpSocket* socket = new QTcpSocket();
	socket->connectToHost(serverName, port, QIODevice::ReadWrite);	
	return new TcpConnection(socket, messageCreator, timeout);
}

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Howere I've solved the problem...without using signal/slots mecanism!

Now I've another problem with disconnection...when I try to use disconnectFromHost from server, It don't disconnect (socket state is still connected) and the socket return a "Network time out" error. Than the Client crash on waitReadyRead.
I try to insert a waitForDisconnected() just after the call of disconnectFromHost but without results: waitForDisconnected return always false ( waiting 30000 msecs too).

Why?

[wysota]

You should really make up your mind if you want to use the event queue or not.