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QSocketNotifier: Socket notifiers cannot be enabled or disabled from another thread

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  • SGaistS SGaist

    What exactly have you tried ?

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    rktech
    wrote on last edited by
    #11

    @SGaist To add override to my code, but I don't know where should I place it...

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    • R Offline
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      rktech
      wrote on last edited by
      #12

      @SGaist How can I send the connection from incomingConnection() to Pool?

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      • R Offline
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        rktech
        wrote on last edited by
        #13

        @SGaist I have successfully overrided the incomingconnection(), but I don't know, how to pass it to the Pool.

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        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by
          #14

          You'll have to redesign your pool a bit to ensure that your sockets are created in the context of the run method of your QThread subclass.

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          • SGaistS SGaist

            You'll have to redesign your pool a bit to ensure that your sockets are created in the context of the run method of your QThread subclass.

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            rktech
            wrote on last edited by
            #15

            @SGaist I know, but how?

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            • SGaistS Offline
              SGaistS Offline
              SGaist
              Lifetime Qt Champion
              wrote on last edited by
              #16

              You have to transfer the descriptor to your pool and there in your run method create new sockets when descriptors are added.

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              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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              • SGaistS SGaist

                You have to transfer the descriptor to your pool and there in your run method create new sockets when descriptors are added.

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                rktech
                wrote on last edited by
                #17

                @SGaist Should I add this part of code to my Pool::add() method? (Of course with editing it)

                QTcpSocket tcpSocket;
                
                    if (!tcpSocket.setSocketDescriptor(socketDescriptor)) {
                        emit error(tcpSocket.error());
                        return;
                    }
                
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                • SGaistS SGaist

                  You have to transfer the descriptor to your pool and there in your run method create new sockets when descriptors are added.

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                  rktech
                  wrote on last edited by
                  #18

                  @SGaist I have (probably) successfully rewritten the Pool add method, but I have another problem. When I add this:

                  protected:
                      void incomingConnection(qintptr socketDescriptor) override;
                  

                  to myserver.h I get this error:

                  ...\myserver.h:35: Chyba: only virtual member functions can be marked 'override'
                  

                  (Chyba is Error in my local)
                  What I am doing wrong?

                  mrjjM 1 Reply Last reply
                  0
                  • R rktech

                    @SGaist I have (probably) successfully rewritten the Pool add method, but I have another problem. When I add this:

                    protected:
                        void incomingConnection(qintptr socketDescriptor) override;
                    

                    to myserver.h I get this error:

                    ...\myserver.h:35: Chyba: only virtual member functions can be marked 'override'
                    

                    (Chyba is Error in my local)
                    What I am doing wrong?

                    mrjjM Offline
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                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by mrjj
                    #19

                    Hi
                    well it is virtual https://doc.qt.io/qt-5/qtcpserver.html#incomingConnection
                    so does Pool inherit QTcpServer ?
                    The error you get says "Hey, i dont see that funtion in base class, so you cant use override"

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                    • mrjjM mrjj

                      Hi
                      well it is virtual https://doc.qt.io/qt-5/qtcpserver.html#incomingConnection
                      so does Pool inherit QTcpServer ?
                      The error you get says "Hey, i dont see that funtion in base class, so you cant use override"

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                      rktech
                      wrote on last edited by
                      #20

                      @mrjj No, the server is build under the myserver class

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                      • R rktech

                        @mrjj No, the server is build under the myserver class

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                        rktech
                        wrote on last edited by
                        #21
                        This post is deleted!
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                        • mrjjM mrjj

                          Hi
                          well it is virtual https://doc.qt.io/qt-5/qtcpserver.html#incomingConnection
                          so does Pool inherit QTcpServer ?
                          The error you get says "Hey, i dont see that funtion in base class, so you cant use override"

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                          rktech
                          wrote on last edited by
                          #22

                          @mrjj the header of server look like:

                          #ifndef MYSERVER_H
                          #define MYSERVER_H
                          
                          #include <QObject>
                          #include <QDebug>
                          #include <QTcpServer>
                          #include <QTcpSocket>
                          #include <QString>
                          #include <QFile>
                          #include <QStandardPaths>
                          #include <QThread>
                          #include <QElapsedTimer>
                          #include <pool.h>
                          #include <QDateTime>
                          class MyServer : public QObject
                          {
                              Q_OBJECT
                          public:
                              explicit MyServer(QObject *parent = nullptr);
                          
                          signals:
                          
                          public slots:
                              void newConnection();
                              void onReadyRead();
                          
                          private:
                              QTcpServer *server;
                              QList<QTcpSocket*>  _sockets;
                              QString a;
                              QString com;
                              QTcpSocket *socket;
                              QList<QTcpSocket*> sl;
                          /*protected:
                              void incomingConnection(qintptr socketDescriptor) override;*/
                          };
                          
                          #endif // MYSERVER_H
                          
                          
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                          • Christian EhrlicherC Offline
                            Christian EhrlicherC Offline
                            Christian Ehrlicher
                            Lifetime Qt Champion
                            wrote on last edited by
                            #23

                            Sorry but please learn C++ first. If you want to override a function from a class you should inherit from this class. So inherit from QTcpServer, override the function and do whatever you want to. This is basic c++ stuff...

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                            • Christian EhrlicherC Christian Ehrlicher

                              Sorry but please learn C++ first. If you want to override a function from a class you should inherit from this class. So inherit from QTcpServer, override the function and do whatever you want to. This is basic c++ stuff...

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                              rktech
                              wrote on last edited by
                              #24

                              @Christian-Ehrlicher That's the thing, that I didn't notice. Thanks

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                              • Christian EhrlicherC Christian Ehrlicher

                                Sorry but please learn C++ first. If you want to override a function from a class you should inherit from this class. So inherit from QTcpServer, override the function and do whatever you want to. This is basic c++ stuff...

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                                rktech
                                wrote on last edited by
                                #25

                                @Christian-Ehrlicher But I don't know, how to edit it.

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                                • R Offline
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                                  rktech
                                  wrote on last edited by
                                  #26

                                  I have rewritten half of my project to solve the problem:
                                  myserver.h

                                  #ifndef MYSERVER_H
                                  #define MYSERVER_H
                                  #include <QStringList>
                                  #include <QTcpServer>
                                  #include <QDateTime>
                                  class MyServer : public QTcpServer
                                  {
                                      Q_OBJECT
                                  
                                  public:
                                      MyServer(QObject *parent = nullptr);
                                  
                                  protected:
                                      void incomingConnection(qintptr socketDescriptor) override;
                                  
                                  private:
                                      QStringList fortunes;
                                  };
                                  
                                  #endif // MYSERVER_H
                                  

                                  myserver.cpp

                                  #include "myserver.h"
                                  #include "pool.h"
                                  Pool p;
                                  
                                  MyServer::MyServer(QObject *parent)
                                      : QTcpServer(parent)
                                  {
                                      p.start();
                                  }
                                  
                                  void MyServer::incomingConnection(qintptr socketDescriptor)
                                  {
                                  QDateTime qdt;
                                  p.add(socketDescriptor,qdt.time());
                                  }
                                  

                                  pool.h

                                  #ifndef POOL_H
                                  #define POOL_H
                                  #include<QObject>
                                  #include<QThread>
                                  #include<QTcpSocket>
                                  #include<QDateTime>
                                  #include<QElapsedTimer>
                                  class Pool : public QThread
                                  {
                                      Q_OBJECT
                                  
                                  protected:
                                      void run();
                                  private:
                                      struct conn{
                                          QTcpSocket *s;
                                          QTime qdt;
                                      };
                                      QList<conn> x;
                                  public:
                                      void add(int socketDescriptor, QTime qdt);
                                  };
                                  #endif // POOL_H
                                  

                                  pool.cpp

                                  #include "pool.h"
                                  #include <QElapsedTimer>
                                  void Pool::run()
                                  {
                                  QElapsedTimer qet;
                                  qet.start();
                                  while (true) {
                                      if(qet.elapsed()>=5000){
                                          foreach (conn y, x) {
                                              if(y.s==nullptr){
                                                  qDebug()<<"empty";
                                                  continue;
                                              }
                                              y.s->write("test");
                                              y.s->flush();
                                          }
                                          qet.restart();
                                      }
                                  }
                                  }
                                  void Pool::add(int socketDescriptor, QTime qdt){
                                  QTcpSocket* s = new QTcpSocket;
                                  s->setSocketDescriptor(socketDescriptor);
                                  s->write("1\n");
                                  conn c;
                                  c.s=s;
                                  c.qdt=qdt;
                                  x.append(c);
                                  }
                                  

                                  But I have still the same error:

                                  QSocketNotifier: Socket notifiers cannot be enabled or disabled from another thread
                                  

                                  What's wrong?

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                                  • SGaistS Offline
                                    SGaistS Offline
                                    SGaist
                                    Lifetime Qt Champion
                                    wrote on last edited by
                                    #27

                                    Because your add method is called in the thread of the tcp server.

                                    As I already told you, the socket creation must happen in the run function.

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                                    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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                                    • SGaistS SGaist

                                      Because your add method is called in the thread of the tcp server.

                                      As I already told you, the socket creation must happen in the run function.

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                                      rktech
                                      wrote on last edited by
                                      #28

                                      @SGaist I have solved it. I am creating a list of descriptors in add() method and then rewriting it like this:
                                      pool.cpp

                                      void Pool::run()
                                      {
                                      QElapsedTimer qet;
                                      qet.start();
                                      while (true) {
                                          if(!d.empty()){
                                              qDebug()<<"rewriting";
                                              for (int i = 0; i<d.size();i++) {
                                                  desc des = d[i];
                                                  conn con;
                                                  QTcpSocket* soc = new QTcpSocket;
                                                  soc->setSocketDescriptor(des.descriptor);
                                                  con.s=soc;
                                                  con.qdt=des.qt;
                                                  d.removeAt(i);
                                                  x.append(con);
                                              }
                                              qDebug()<<"done";
                                          }
                                          if(qet.elapsed()>=5000){
                                              foreach (conn y, x) {
                                                  if(!y.s->isOpen()){
                                                      qDebug()<<"empty";
                                                      continue;
                                                  }
                                                  y.s->write("test");
                                                  qDebug()<<"l";
                                                  y.s->flush();
                                              }
                                              qet.restart();
                                          }
                                      }
                                      }
                                      void Pool::add(int socketDescriptor, QTime qdt){
                                      desc de;
                                      de.descriptor=socketDescriptor;
                                      de.qt=qdt;
                                      d.append(de);
                                      }
                                      

                                      definitions of structs and lists in pool.h:

                                        struct conn{
                                              QTcpSocket *s;
                                              QTime qdt;
                                          };
                                          struct desc{
                                              qintptr descriptor;
                                              QTime qt;
                                          };
                                          QList<conn> x;
                                          QList<desc> d;
                                      
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                                      • SGaistS Offline
                                        SGaistS Offline
                                        SGaist
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #29

                                        You are missing one important thing: you are accessing a resource from two different threads. You should protect its access accordingly.

                                        Interested in AI ? www.idiap.ch
                                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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                                        • SGaistS SGaist

                                          You are missing one important thing: you are accessing a resource from two different threads. You should protect its access accordingly.

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                                          rktech
                                          wrote on last edited by
                                          #30

                                          @SGaist In my last code it is fixed, right? If no, how to protect it correctly?

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