[SOLVED] Problem with TcpListener

[filipekczek7]

(In the beginning, sorry for my english )

I'm new on this forum, so I would like to greet you all

OK, I have some experience with SFML. About 3 months ago I became interested in sockets (and then threads). I have made simple chat with sockets (with port forwarding)... And it works, yey, it's so easy and I understand it So now I want to make some network game. The first step is listen to connection. OK, here is some code:



Function which displays text and launching listening thread:

void Game::playOnlineServerMenu()
{
    //setting texts
        int textsNumber=3;
        Text texts[textsNumber];
    //string strings[textsNumber]={"Play","Options","Credits","Exit"};
        for(int i=0;i<textsNumber;i++)
        {
                texts[i].setFont(font);
                texts[i].setCharacterSize(150);
        if(i==0)
            texts[i].setString("Waiting for connection...");
        else if(i==1)
        {
            string ip="Your IP is: "+IpAddress::getPublicAddress().toString();
            texts[i].setString(ip);
        }

                if(i<1)
            texts[i].setPosition(window.getSize().x/2-texts[i].getGlobalBounds().width/2,250+i*120);
        else if(i==1)
            texts[i].setPosition(window.getSize().x/2-texts[i].getGlobalBounds().width/2,250+i*120);

        texts[i].setColor(Color(175,175,175));
        }

    //listening to client
        thread.launch();

    //main loop
        while(menuState==playOnlineServer)
        {
            cout << "Main loop" << endl;

                Event event;

                while(window.pollEvent(event))
                {
                    //pressed X button
                        if(event.type==Event::Closed)
            {
                thread.terminate();
                menuState=exit;
            }
                        //released escape button
                        if(event.type==Event::KeyPressed&&event.key.code==Keyboard::Escape)
            {
                thread.terminate();
                menuState=menu;
            }
                }

        window.setMouseCursorVisible(true);
        window.setView(window.getDefaultView());
                window.clear();
                for(int i=0;i<textsNumber;i++)
            window.draw(texts[i]);
                window.display();
        }
}

Listening and accepting connection function:

void Game::listening()
{
    Lock lock(mutex);

    cout << "Thread" << endl;

    //listening to connection
    if(listener.listen(port)!=Socket::Done)
        cout << "!ERROR! Server didn't find any connection." << endl;
    else
        cout << "Connection found" << endl;
    //accepting connection
    if(listener.accept(socket)!=Socket::Done)
        cout << "!ERROR! Server cannot accept connection." << endl;
    else
    {
        cout << "Connection accepted" << endl;
        listener.close();
        menuState=gameOnlineServer;
    }
}

Thread is class member, so it's initialized correctly:

Game::Game():thread(&Game::listening,this)
{
    //...
}

I'm gonna transform my code to something better (polymorphism, virtual functions and generally better code design), but it has to work.

OK, so I choose "Server" option, then I see my IP and some text, then I press Escape key and leave whole program. That's what I see in the console output:

Main loop
Thread
Connection found
Main loop
Main loop
Main loop
Main loop
Main loop
...

What?! Listener immediately found connection? But there's not "!ERROR! Server cannot accept connection." or "Connection accepted". I don't understand. I removed thread and just called listening function after draw everything:

Main loop
Thread
Connection found

I don't know what's going on :/ Situation didn't change, so it's not thread fault. My previous network programs work, so I don't know what's wrong with this :/ I solved previous problems, but this is problem with SFML sockets, so I have no idea what's wrong.

Thanks for help.

[Laurent]

TcpListener::listen just... listens. It doesn't mean that there is a connection. Accepting connections is done with (surprisingly) TcpListener::accept

So there's no problem in your program. Don't hesitate to read the documentation / tutorials again to make things clear.

[filipekczek7]

Yes, I know what listen() and accept() functions do And yes, there's no problem in my program. No, sorry, there is a problem, but I can't see it :| Doesn't listener call accept() function only when listen() found something? You know:

listener is listening...
listener is accepting connection, because it found something, some connection

Why listener stops listening after first approach? I don't understand... No, wait. So... listener.listen(port) is Socket::Done when it's listening? Not only when it found some connection?

[filipekczek7]

THANKS!!! OMG!!! You're genius! Or even if you are not genius, I'm very stupid Thanks for some knowledge, I'll remember that. I thought "Hm, if listen() is Socket::Done when it's listening... Wait... Oh, come on! I didn't remove comment from the code fragment in other file!" No comment BADUM-TSS! yeah, I know, not funny. Small bug, but after fix repairs everything.

Thank you for me to realize that it works OK, the topis is closed, my mistake Is there possibility to close topic?

PS: thank you for creating SFML

[Hapax]

Is there possibility to close topic?

Just rename the Subject of the thread in the original post so that it starts with [SOLVED]
i.e. "[SOLVED] Problem with TcpListener"

[filipekczek7]

Oh, OK, thanks