QTcpServer not handling connections.

[spraff]

I've been having trouble getting my client/server code to work. Here's a little test program I put together to test my sanity.

server.hpp:

#include <QObject>
class QTcpServer;
 
class Server : public QObject {
	Q_OBJECT
public:
	Server();
	bool done();
private slots:
	void newConnection();
private:
	bool d;
	QTcpServer * s;
};

#include <QObject>
class QTcpServer;

class Server : public QObject {
	Q_OBJECT
public:
	Server();
	bool done();
private slots:
	void newConnection();
private:
	bool d;
	QTcpServer * s;
};

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server.cpp:

#include "server.hpp"
#include <QTcpServer>
#include <QTcpSocket>
 
Server::Server() {
	d = false;
	s = new QTcpServer(this);
	s->listen(QHostAddress::Any, 123456);
	connect(s,SIGNAL(newConnection()),
		this,SLOT(newConnection()) );
}
 
bool Server::done() {
	return d;
}
 
void Server::newConnection() {
	QTcpSocket * sock = s->nextPendingConnection();
	qWarning() << "Got one.";
	delete sock;
}

#include "server.hpp"
#include <QTcpServer>
#include <QTcpSocket>

Server::Server() {
	d = false;
	s = new QTcpServer(this);
	s->listen(QHostAddress::Any, 123456);
	connect(s,SIGNAL(newConnection()),
		this,SLOT(newConnection()) );
}

bool Server::done() {
	return d;
}

void Server::newConnection() {
	QTcpSocket * sock = s->nextPendingConnection();
	qWarning() << "Got one.";
	delete sock;
}

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servermain.cpp:

#include "server.hpp"
 
int main() {
	Server s;
	while (!s.done()) {
	}
	return 0;
}

#include "server.hpp"

int main() {
	Server s;
	while (!s.done()) {
	}
	return 0;
}

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clientmain.cpp:

#include <QTcpSocket>
#include <iostream>
 
int main() {
	char c;
	QTcpSocket * sock;
 
	while (std::cin >> c) {
		switch(c) {
		case 'c':
			sock = new QTcpSocket();
			sock->connectToHost("127.0.0.1",123456);
			if(sock->waitForConnected()) {
				qWarning() << "OK";
			}
			else {
				qWarning() << "NO";
			}
			delete sock;
		};
	}
	return 0;
}

#include <QTcpSocket>
#include <iostream>

int main() {
	char c;
	QTcpSocket * sock;

	while (std::cin >> c) {
		switch(c) {
		case 'c':
			sock = new QTcpSocket();
			sock->connectToHost("127.0.0.1",123456);
			if(sock->waitForConnected()) {
				qWarning() << "OK";
			}
			else {
				qWarning() << "NO";
			}
			delete sock;
		};
	}
	return 0;
}

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If I fire up both programs in separate terminals, the client coughs out "OK" every time you enter a 'c', but the server never does anything, and in a debugger the newConnection slot is never executed. What's going on?

Thanks already.

[caduel]

123456 is probably an invalid port number. Try something smaller like 55555 for testing.

[spraff]

Well I feel kinda dumb for having an out-of-range port, but with that fixed the behaviour's the same.

[pastor]

2 spraff: If I don't miss my guess, the total number of network ports is 65534.

Do you have a firewall? May be, it blocked your connection?

//updated

Ahh, I looked at your code.

1) You don't use QCoreApplication (or QApplication) instance in your applications
2) It's bad idea to use infinity loop. Use qApp->quit() for that.

Try this code:

#include "server.hpp"
 
int main(int argc, char **argv) 
{
    QCoreApplication app(argc, argv);
    Server s;
    return app.exec();
}

#include "server.hpp"
 
int main(int argc, char **argv) 
{
    QCoreApplication app(argc, argv);
    Server s;
    return app.exec();
}

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#include <QTcpSocket>
#include <iostream>
 
int main(int argc, char **argv) {
    QCoreApplication app(argc, argv);
    char c;
    QTcpSocket * sock;
 
    while (std::cin >> c) {
        switch(c) {
        case 'c':
            sock = new QTcpSocket();
            sock->connectToHost("127.0.0.1",123456);
            if(sock->waitForConnected()) {
                qWarning() << "OK";
            }
            else {
                qWarning() << "NO";
            }
            delete sock;
        };
    }
    return app.exec();
}

#include <QTcpSocket>
#include <iostream>
 
int main(int argc, char **argv) {
    QCoreApplication app(argc, argv);
    char c;
    QTcpSocket * sock;
 
    while (std::cin >> c) {
        switch(c) {
        case 'c':
            sock = new QTcpSocket();
            sock->connectToHost("127.0.0.1",123456);
            if(sock->waitForConnected()) {
                qWarning() << "OK";
            }
            else {
                qWarning() << "NO";
            }
            delete sock;
        };
    }
    return app.exec();
}

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[caduel]

True... you do need a running QEventLoop for Qt to process network events and send you signals. So do put a QCoreApplication into your main() as suggested by prastor.