Messages

1

Network / Re: SocketSelector wait() doesn't return true after a client TcpSocket disconnect

« on: October 11, 2023, 05:43:29 pm »

I have investigated the issue in more depth;

It seems like calling disconnect() causes TcpSocket to go INVALID_SOCKET therefore wait() function return false due to winapi select() returning error(-1) because it still sees a socket is valid and returning error.

Calling TcpSocket::disconnect() first and then calling SocketSelector::remove() also doesn't remove it because the socket goes INVALID_SOCKET state resulting wait() return false.

The conculusion is to remove the socket from selector before disconnecting it. But then you can not receive the disconnection data from SocketSelector...

2

Network / Re: SocketSelector wait() doesn't return true after a client TcpSocket disconnect

« on: October 11, 2023, 11:27:30 am »

One more thing to note here is that, after TcpSocket::disconnect() is called, the wait(1000) starts to return without waiting the timeout value.

3

Network / Re: SocketSelector wait() doesn't return true after a client TcpSocket disconnect

« on: October 11, 2023, 11:15:18 am »

With a simple modification I have tested the same problem on client side disconnecting tcpSocket the result is same. Client SocketSelector can't detect the disconnect but servers SocketSelector can.

sf::TcpListener tcpListener;
sf::SocketSelector socketSelector;
sf::TcpSocket clientSocket;
std::mutex lock;
bool disconnectClient = false;

void Server()
{
        sf::Socket::Status tcpStatus = tcpListener.listen(LOGIN_SERVER_PORT);
        if (tcpStatus != sf::Socket::Done)
        {
                std::cout << "[Server] TcpListener couldn&#39;t be initialized!" << std::endl;
                return;
        }
        else
        {
                std::cout << "[Server] TcpListener initialized!" << std::endl;
        }

        sf::Socket::Status acceptStatus = tcpListener.accept(clientSocket);
        if (acceptStatus == sf::Socket::Done)
        {
                std::cout << "[Server] A new client is accepted!" << std::endl;
                socketSelector.add(clientSocket);

                std::cout << "[Server] Starting to listen with socket selector!" << std::endl;
                while (true)
                {
                        lock.lock();
                        if (socketSelector.wait(sf::milliseconds(1000)))
                        {
                                std::cout << "[Server] socketSelector.wait() returns true" << std::endl;

                                if (socketSelector.isReady(clientSocket))
                                {
                                        std::cout << "[Server] socketSelector.isReady(clientSocket) returns true" << std::endl;
                                }
                                else
                                {
                                        std::cout << "[Server] socketSelector.isReady(clientSocket) returns false" << std::endl;
                                }
                        }
                        else
                        {
                                std::cout << "[Server] socketSelector.wait() returns false" << std::endl;
                        }
                        lock.unlock();
                        Sleep(100);
                }
        }

}

void Client()
{
        sf::SocketSelector selector;
        sf::TcpSocket tcpSocket;
        sf::Socket::Status status = tcpSocket.connect(GSO_SERVER_IP, LOGIN_SERVER_PORT, sf::milliseconds(1000));
        if (status != sf::Socket::Done)
        {
                std::cout << "[Client] Connection to server failed!" << std::endl;
                return;
        }
        else
        {
                std::cout << "[Client] Connected to server!" << std::endl;
        }

        selector.add(tcpSocket);

        bool waiting = true;
        while (waiting)
        {
                lock.lock();
                if (selector.wait(sf::milliseconds(1000)))
                {
                        std::cout << "[Client] SocketSelector returns true!" << std::endl;
                        if (selector.isReady(tcpSocket))
                        {
                                std::cout << "[Client] SocketSelector tcpSocket is ready!" << std::endl;
                                waiting = false;
                        }
                        else
                        {
                                std::cout << "[Client] SocketSelector tcpSocket is not ready!" << std::endl;
                        }
                }
                else
                {
                        std::cout << "[Client] SocketSelector returns false!" << std::endl;
                }
                lock.unlock();
                Sleep(100);
                if (disconnectClient)
                {
                        std::cout << "[Client] Disconnecting tcp socket" << std::endl;
                        tcpSocket.disconnect();
                        disconnectClient = false;
                }
        }
}

int main()
{
        std::thread s(Server);
        Sleep(1000);
        std::thread c(Client);

        while (true)
        {
                int i;
                std::cin >> i;
                if(i == 0)
                {
                        lock.lock();
                        std::cout << "[MainThread] Lock is locked. Sending disconnect command!" << std::endl;
                        disconnectClient = true;
                        lock.unlock();
                }
        }

        return 0;
}

[Server] TcpListener initialized!
[Client] Connected to server!
[Server] A new client is accepted!
[Server] Starting to listen with socket selector!
[Client] SocketSelector returns false!
[Server] socketSelector.wait() returns false
[Client] SocketSelector returns false!
[Server] socketSelector.wait() returns false
[Client] SocketSelector returns false!
[Server] socketSelector.wait() returns false
[Client] SocketSelector returns false!
[Server] socketSelector.wait() returns false
0
[Client] SocketSelector returns false!
[Server] socketSelector.wait() returns false
[MainThread] Lock is locked. Sending disconnect command!
[Client] SocketSelector returns false!
[Client] Disconnecting tcp socket
[Server] socketSelector.wait() returns true
[Server] socketSelector.isReady(clientSocket) returns true
[Client] SocketSelector returns false!
[Client] SocketSelector returns false!
[Server] socketSelector.wait() returns true
[Server] socketSelector.isReady(clientSocket) returns true
[Client] SocketSelector returns false!
[Server] socketSelector.wait() returns true
[Server] socketSelector.isReady(clientSocket) returns true

4

Network / SocketSelector wait() doesn't return true after a client TcpSocket disconnect

« on: October 11, 2023, 11:08:26 am »

Hello, I have written a simple code to show the situation and also attaching console output. On the server side I just call TcpSocket::disconnect() for a client socket but SocketSelector wait always returns false but the client SocketSelector can detect the disconnection.

I am not sure this is an expected behaviour.

Thanks in advance!

Using SFML 2.6.0 official release on Windows 10 Machine

sf::TcpListener tcpListener;
sf::SocketSelector socketSelector;
sf::TcpSocket clientSocket;
std::mutex lock;
bool disconnectClientSocket = false;

void Server()
{

        sf::Socket::Status tcpStatus = tcpListener.listen(LOGIN_SERVER_PORT);
        if (tcpStatus != sf::Socket::Done)
        {
                std::cout << "[Server] TcpListener couldn&#39;t be initialized!" << std::endl;
                return;
        }
        else
        {
                std::cout << "[Server] TcpListener initialized!" << std::endl;
        }

        sf::Socket::Status acceptStatus = tcpListener.accept(clientSocket);
        if (acceptStatus == sf::Socket::Done)
        {
                std::cout << "[Server] A new client is accepted!" << std::endl;
                socketSelector.add(clientSocket);

                std::cout << "[Server] Starting to listen with socket selector!" << std::endl;
                while (true)
                {
                        lock.lock();
                        if (socketSelector.wait(sf::milliseconds(1000)))
                        {
                                std::cout << "[Server] socketSelector.wait() returns true" << std::endl;

                                if (socketSelector.isReady(clientSocket))
                                {
                                        std::cout << "[Server] socketSelector.isReady(clientSocket) returns true" << std::endl;
                                }
                                else
                                {
                                        std::cout << "[Server] socketSelector.isReady(clientSocket) returns false" << std::endl;
                                }
                        }
                        else
                        {
                                std::cout << "[Server] socketSelector.wait() returns false" << std::endl;
                        }
                        lock.unlock();

                        Sleep(100);

                        if (disconnectClientSocket)
                        {
                                std::cout << "[Server] Disconnecting client socket" << std::endl;
                                clientSocket.disconnect();
                                disconnectClientSocket = false;
                        }
                }
        }
       
}

void Client()
{
        sf::SocketSelector selector;
        sf::TcpSocket tcpSocket;
        sf::Socket::Status status = tcpSocket.connect(GSO_SERVER_IP, LOGIN_SERVER_PORT, sf::milliseconds(1000));
        if (status != sf::Socket::Done)
        {
                std::cout << "[Client] Connection to server failed!" << std::endl;
                return;
        }
        else
        {
                std::cout << "[Client] Connected to server!" << std::endl;
        }

        selector.add(tcpSocket);
       
        bool waiting = true;
        while (waiting)
        {
                if (selector.wait())
                {
                        std::cout << "[Client] SocketSelector returns true!" << std::endl;
                        if (selector.isReady(tcpSocket))
                        {
                                std::cout << "[Client] SocketSelector tcpSocket is ready!" << std::endl;
                                waiting = false;
                        }
                        else
                        {
                                std::cout << "[Client] SocketSelector tcpSocket is not ready!" << std::endl;
                        }
                }
                else
                {
                        std::cout << "[Client] SocketSelector returns false!" << std::endl;
                }
                Sleep(100);    
        }
}


int main()
{
        std::thread s(Server);
        Sleep(1000);
        std::thread c(Client);

        while (true)
        {
                int i;
                std::cin >> i;
                if(i == 0)
                {
                        lock.lock();
                        std::cout << "[MainThread] Lock is locked. Sending disconnect command!" << std::endl;
                        disconnectClientSocket = true;
                        lock.unlock();
                }
        }

        return 0;
}

[Server] TcpListener initialized!
[Server] A new client is accepted!
[Server] Starting to listen with socket selector!
[Client] Connected to server!
[Server] socketSelector.wait() returns false
[Server] socketSelector.wait() returns false
[Server] socketSelector.wait() returns false
[Server] socketSelector.wait() returns false
0
[Server] socketSelector.wait() returns false
[MainThread] Lock is locked. Sending disconnect command!
[Server] Disconnecting client socket
[Server] socketSelector.wait() returns false
[Client] SocketSelector returns true!
[Client] SocketSelector tcpSocket is ready!
[Server] socketSelector.wait() returns false
[Server] socketSelector.wait() returns false
[Server] socketSelector.wait() returns false
[Server] socketSelector.wait() returns false
[Server] socketSelector.wait() returns false
[Server] socketSelector.wait() returns false
[Server] socketSelector.wait() returns false