sockets - QT QTcpServer::incomingConnection(qintptr handle) not firing? -

i'm trying create multithreaded server using qt first time. 1 use socket pointer returned qtcpserver::nextpendingconnection() socket handle baked in - since i'm interfacing connecting client on separate thread, need create socket separately using qintptr handle qtcpserver::incomingconnection(qintptr handle). after dreary, error-packed debugging session managed track down problem qtcpserver::incomingconnection() never being fired?

has had similar problem - has changed on recent versions qt?

these ones i've tried:

• qtcpserver::incomingconnection(qintptr handle)
• qtcpserver::incomingconnection(qintptr socketdescriptor)
• qtcpserver::incomingconnection(int handle)

edit:

creating instance of server:

testserver *myserver = new testserver(); myserver->initializeserver(1234); 

which calls:

void testserver::initializeserver(quint16 port) {  mainserver = new qtcpserver(this);  mainserver->listen(qhostaddress::any, port);  qdebug() << "listening connections on port: " << port;    } 

server listening. when client connects incomingconnection(qintptr handle) supposed called:

void testserver::incomingconnection(qintptr socketdescriptor){  testclient *client = new testclient(this); client->setsocket(socketdescriptor);  } 

which calls:

void testclient::setsocket(quint16 socketdescr) { socket = new qtcpsocket(this);  socket->setsocketdescriptor(socketdescr);  connect(socket, signal(connected()),this,slot(connected())); connect(socket, signal(disconnected()),this,slot(disconnected())); connect(socket, signal(readyread()),this,slot(readyread()));    } 

called on connect() signal:

void testclient::connected() {    qdebug() << "client connected..."; // debug never appears in console, since qtcpserver::incomingconnection isn't being fired.  } 

you have errors @ code:

1. at testserver qtcpserver aggregated, need inherit it. @ case try override incomingconnection() method, haven't base class , create new incomingconnection(), not override.
2. you qintptr descriptor variable incomingconnection(), set quint16 type @ setsocket() method.
3. you mix client of server , client of part, incoming connection , handling socket data.

i write little example below understanding tcp client-server communication.

server part

main part server themselves:

#include <qtcpserver>  class testserver: public qtcpserver { public:     testserver(qobject *parent = 0);     void incomingconnection(qintptr handle) q_decl_override; }; 

just look: don't aggragate qtcpserver, inherited it. @ case can override incomingconnection() method correctly. @ constructor start server listening using listen() method:

testserver::testserver(qobject *parent):     qtcpserver(parent) {     if (this->listen(qhostaddress::any, 2323)) {         qdebug() << "server start @ port: " << this->serverport();     } else {         qdebug() << "start failure";     } } 

then time overriding incomingconnection():

void testserver::incomingconnection(qintptr handle) {     qdebug() << q_func_info << " new connection";     socketthread *socket = new socketthread(handle);      connect(socket, signal(finished()), socket, slot(deletelater()));     socket->start(); } 

i create socketthread object handle incoming data:

#include <qthread> #include <qobject>  class qtcpsocket;  class socketthread: public qthread {     q_object public:     socketthread(qintptr descriptor, qobject *parent = 0);     ~socketthread();  protected:     void run() q_decl_override;  private slots:     void onconnected();     void onreadyread();     void ondisconnected();  private:     qtcpsocket *m_socket;     qintptr m_descriptor; }; 

we inherits qthread making our server multithreading, have override run() method:

socketthread::socketthread(qintptr descriptor, qobject *parent)     :  qthread(parent), m_descriptor(descriptor) {  }  void socketthread::run() {     qdebug() << q_func_info;     m_socket = new qtcpsocket;     m_socket->setsocketdescriptor(m_descriptor);      connect(m_socket, signal(readyread()),    this, slot(onreadyread()), qt::directconnection);     connect(m_socket, signal(disconnected()), this, slot(ondisconnected()), qt::directconnection);      exec(); } 

this way initialize our qtcpsocket, set socket descriptor, connect readyread() , disconnected() signals , start event loop.

void socketthread::onreadyread() {     qdatastream in(m_socket);     in.setversion(qdatastream::qt_5_5);      qstring message;     in >> message;     qdebug() << message;      m_socket->disconnectfromhost(); }  void socketthread::ondisconnected() {     m_socket->close();     // exit event loop     quit(); } 

at onreadyread() read qstring client, write console , disconnect host. @ ondisconnected() close socket connection , exit event loop.

client part

it example , bad-smells style, create connection server @ mainwindow class on qpushbutton::clicked signal:

void mainwindow::on_pushbutton_clicked() {     qtcpsocket *client = new qtcpsocket;     connect(client, signal(connected()), this, slot(connected()));     connect(client, signal(disconnected()), client, slot(deletelater()));      client->connecttohost(qhostaddress::localhost, 2323);     client->waitforconnected();      if (client->state() != qabstractsocket::connectedstate ) {         qdebug() << q_func_info << " can't connect host";         delete client;         return;     }     qbytearray block;     qdatastream out(&block, qiodevice::writeonly);     out.setversion(qdatastream::qt_5_5);     out << qstring("hello");     out.device()->seek(0);     client->write(block); }  void mainwindow::connected() {     qdebug() << q_func_info << " client connected"; } 

i create new qtcpsocket, connect signals , try connect host(in case localhost). wait connected , check socket status. if right write socket qstring - example.

it 1 of possible ways organized multithreading client-server architecture, hope helpfull , find yours bugs.