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Create object in another object

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  • D Offline
    D Offline
    Damian7546
    wrote on last edited by
    #15

    anyway, can anyone demonstrate why the above code doesn't work when created from the constructor? but works with the main.cpp one?

    jsulmJ 1 Reply Last reply
    0
    • D Damian7546

      anyway, can anyone demonstrate why the above code doesn't work when created from the constructor? but works with the main.cpp one?

      jsulmJ Offline
      jsulmJ Offline
      jsulm
      Lifetime Qt Champion
      wrote on last edited by
      #16

      @Damian7546 If your application crashes then the first thing to do is: use the debugger.
      So, please run your app in debugger and post the stack trace after the crash here...

      https://forum.qt.io/topic/113070/qt-code-of-conduct

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      0
      • Christian EhrlicherC Offline
        Christian EhrlicherC Offline
        Christian Ehrlicher
        Lifetime Qt Champion
        wrote on last edited by
        #17

        Your code crashes in the dtor of RfidSerialWorker (if doWork() would reach it's end), also it's using a blocking approach instead signals and slots to wait for data, the strange while(1) - loop does never exits and at last ít's accessing outFrameQueue from two different threads without proper locking mechanisms (and before you ask - read and understand at least https://doc.qt.io/qt-6/threads-synchronizing.html before fiddling around with threads for no reason).

        Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
        Visit the Qt Academy at https://academy.qt.io/catalog

        1 Reply Last reply
        2
        • D Offline
          D Offline
          Damian7546
          wrote on last edited by
          #18

          @Christian-Ehrlicher so I will do like you propose.

          1 Reply Last reply
          0
          • D Offline
            D Offline
            Damian7546
            wrote on last edited by Damian7546
            #19

            I think that no a problem with thread.

            I remove thread and create my object like below:

              QQueue<RfidFrame*> outFrameQueue;
                RfidSerialWorker *rfidSerialWorker = new RfidSerialWorker(&outFrameQueue);
                RfidFrameProcessor *rfidFrameProcessor = new RfidFrameProcessor(&outFrameQueue);
            
                connect(rfidSerialWorker, SIGNAL(frameReceived(RfidFrame*)), rfidFrameProcessor, SLOT(FrameIncoming(RfidFrame*)));
                connect(rfidFrameProcessor, SIGNAL(frameSend()), rfidSerialWorker, SLOT(frameToSend()));
                rfidSerialWorker->initSerialPort();
            
                //tests - try send frame cyclically
                QTimer *timer = new QTimer(this);
                QObject::connect(timer, SIGNAL(timeout()), rfidFrameProcessor , SLOT(update_power_ind()));
                timer->start(2000);
            

            Function which one try send frame is below:

            void RfidFrameProcessor::update_power_ind()
            {
                readSourceRSx(1,9);
            }
            void RfidFrameProcessor::readSourceRSx(quint8 addr, quint8 source)
            {
            
                QByteArray data;
                data.append(source);
                RfidFrame *frameToSend = new RfidFrame(addr, C_ReadSourceRSx, data);
                qDebug() << "Get lenght from frameToSend: " << frameToSend->GetDataLength();
                m_outFrameQueue->enqueue(frameToSend);
                emit frameSend();
            
            }
            

            and problem is in the same step:
            m_outFrameQueue->enqueue(frameToSend); despite the fact that in frameToSend I have data like you can see in below in Application Output.

            zz.jpg

            jsulmJ JonBJ 2 Replies Last reply
            0
            • D Damian7546

              I think that no a problem with thread.

              I remove thread and create my object like below:

                QQueue<RfidFrame*> outFrameQueue;
                  RfidSerialWorker *rfidSerialWorker = new RfidSerialWorker(&outFrameQueue);
                  RfidFrameProcessor *rfidFrameProcessor = new RfidFrameProcessor(&outFrameQueue);
              
                  connect(rfidSerialWorker, SIGNAL(frameReceived(RfidFrame*)), rfidFrameProcessor, SLOT(FrameIncoming(RfidFrame*)));
                  connect(rfidFrameProcessor, SIGNAL(frameSend()), rfidSerialWorker, SLOT(frameToSend()));
                  rfidSerialWorker->initSerialPort();
              
                  //tests - try send frame cyclically
                  QTimer *timer = new QTimer(this);
                  QObject::connect(timer, SIGNAL(timeout()), rfidFrameProcessor , SLOT(update_power_ind()));
                  timer->start(2000);
              

              Function which one try send frame is below:

              void RfidFrameProcessor::update_power_ind()
              {
                  readSourceRSx(1,9);
              }
              void RfidFrameProcessor::readSourceRSx(quint8 addr, quint8 source)
              {
              
                  QByteArray data;
                  data.append(source);
                  RfidFrame *frameToSend = new RfidFrame(addr, C_ReadSourceRSx, data);
                  qDebug() << "Get lenght from frameToSend: " << frameToSend->GetDataLength();
                  m_outFrameQueue->enqueue(frameToSend);
                  emit frameSend();
              
              }
              

              and problem is in the same step:
              m_outFrameQueue->enqueue(frameToSend); despite the fact that in frameToSend I have data like you can see in below in Application Output.

              zz.jpg

              jsulmJ Offline
              jsulmJ Offline
              jsulm
              Lifetime Qt Champion
              wrote on last edited by
              #20

              @Damian7546 said in Create object in another object:

              and problem is in the same step

              And again: is m_outFrameQueue a valid pointer?

              https://forum.qt.io/topic/113070/qt-code-of-conduct

              D 1 Reply Last reply
              0
              • jsulmJ jsulm

                @Damian7546 said in Create object in another object:

                and problem is in the same step

                And again: is m_outFrameQueue a valid pointer?

                D Offline
                D Offline
                Damian7546
                wrote on last edited by
                #21

                @jsulm In my opinion yes, but I am beginner.... Please explain me.
                .h

                class RfidFrameProcessor : public QObject
                {
                    Q_OBJECT
                public:
                    explicit RfidFrameProcessor(QQueue<RfidFrame*> *outFrameQueue, QObject *parent = nullptr);
                private:
                    QQueue<RfidFrame*> *m_outFrameQueue;
                }
                
                

                .cpp

                RfidFrameProcessor::RfidFrameProcessor(QQueue<RfidFrame*> *outFrameQueue,QObject *parent)
                    : QObject(parent)
                {
                    m_outFrameQueue = outFrameQueue;
                }
                
                jsulmJ 1 Reply Last reply
                0
                • D Damian7546

                  @jsulm In my opinion yes, but I am beginner.... Please explain me.
                  .h

                  class RfidFrameProcessor : public QObject
                  {
                      Q_OBJECT
                  public:
                      explicit RfidFrameProcessor(QQueue<RfidFrame*> *outFrameQueue, QObject *parent = nullptr);
                  private:
                      QQueue<RfidFrame*> *m_outFrameQueue;
                  }
                  
                  

                  .cpp

                  RfidFrameProcessor::RfidFrameProcessor(QQueue<RfidFrame*> *outFrameQueue,QObject *parent)
                      : QObject(parent)
                  {
                      m_outFrameQueue = outFrameQueue;
                  }
                  
                  jsulmJ Offline
                  jsulmJ Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on last edited by
                  #22

                  @Damian7546 said in Create object in another object:

                  m_outFrameQueue = outFrameQueue;

                  I laready asked that before: is outFrameQueue a valid pointer?

                  https://forum.qt.io/topic/113070/qt-code-of-conduct

                  1 Reply Last reply
                  0
                  • D Offline
                    D Offline
                    Damian7546
                    wrote on last edited by Damian7546
                    #23

                    Ok,
                    I create in this way:

                     QQueue<RfidFrame*> outFrameQueue;
                        RfidSerialWorker *rfidSerialWorker = new RfidSerialWorker(&outFrameQueue);
                        RfidFrameProcessor *rfidFrameProcessor = new RfidFrameProcessor(&outFrameQueue);
                    

                    But in class

                       Q_OBJECT
                    public:
                        explicit RfidFrameProcessor(QQueue<RfidFrame*> *outFrameQueue, QObject *parent = nullptr);
                    private:
                        QQueue<RfidFrame*> *m_outFrameQueue;
                    
                    1 Reply Last reply
                    0
                    • D Damian7546

                      I think that no a problem with thread.

                      I remove thread and create my object like below:

                        QQueue<RfidFrame*> outFrameQueue;
                          RfidSerialWorker *rfidSerialWorker = new RfidSerialWorker(&outFrameQueue);
                          RfidFrameProcessor *rfidFrameProcessor = new RfidFrameProcessor(&outFrameQueue);
                      
                          connect(rfidSerialWorker, SIGNAL(frameReceived(RfidFrame*)), rfidFrameProcessor, SLOT(FrameIncoming(RfidFrame*)));
                          connect(rfidFrameProcessor, SIGNAL(frameSend()), rfidSerialWorker, SLOT(frameToSend()));
                          rfidSerialWorker->initSerialPort();
                      
                          //tests - try send frame cyclically
                          QTimer *timer = new QTimer(this);
                          QObject::connect(timer, SIGNAL(timeout()), rfidFrameProcessor , SLOT(update_power_ind()));
                          timer->start(2000);
                      

                      Function which one try send frame is below:

                      void RfidFrameProcessor::update_power_ind()
                      {
                          readSourceRSx(1,9);
                      }
                      void RfidFrameProcessor::readSourceRSx(quint8 addr, quint8 source)
                      {
                      
                          QByteArray data;
                          data.append(source);
                          RfidFrame *frameToSend = new RfidFrame(addr, C_ReadSourceRSx, data);
                          qDebug() << "Get lenght from frameToSend: " << frameToSend->GetDataLength();
                          m_outFrameQueue->enqueue(frameToSend);
                          emit frameSend();
                      
                      }
                      

                      and problem is in the same step:
                      m_outFrameQueue->enqueue(frameToSend); despite the fact that in frameToSend I have data like you can see in below in Application Output.

                      zz.jpg

                      JonBJ Offline
                      JonBJ Offline
                      JonB
                      wrote on last edited by JonB
                      #24

                      @Damian7546 said in Create object in another object:

                      QQueue<RfidFrame*> outFrameQueue;
                      RfidSerialWorker *rfidSerialWorker = new RfidSerialWorker(&outFrameQueue);
                      RfidFrameProcessor *rfidFrameProcessor = new RfidFrameProcessor(&outFrameQueue);
                      ...
                      timer->start(2000);
                      

                      If I understand your code right. QQueue<RfidFrame*> outFrameQueue is a local variable in some method? But once you have set off the timer you exit that method, right? So the QQueue<RfidFrame*> outFrameQueue goes out of scope and gets destroyed at that point. Yet you have passed that queue as a parameter to RfidSerialWorker/RfidFrameProcessor, they have set a m_outFrameQueue to point to that queue passed in, it is no longer valid, but they still use it => disaster. Is my analysis correct for your code?

                      I'm not sure, but it sounds like your QQueue<RfidFrame*> outFrameQueue; should not be local variable in a method but rather a persistent member variable?

                      1 Reply Last reply
                      1
                      • D Offline
                        D Offline
                        Damian7546
                        wrote on last edited by
                        #25

                        Thanks QQueue<RfidFrame*> outFrameQueue i wolud like to pass frame to send beetwen RfidSerialWorker and RfidFrameProcessor.

                        @JonB said in Create object in another object:

                        I'm not sure, but it sounds like your QQueue<RfidFrame*> outFrameQueue; should not be local variable in a method but rather a persistent member variable?

                        Exactly. But how do this ?

                        jsulmJ 1 Reply Last reply
                        0
                        • D Damian7546

                          Thanks QQueue<RfidFrame*> outFrameQueue i wolud like to pass frame to send beetwen RfidSerialWorker and RfidFrameProcessor.

                          @JonB said in Create object in another object:

                          I'm not sure, but it sounds like your QQueue<RfidFrame*> outFrameQueue; should not be local variable in a method but rather a persistent member variable?

                          Exactly. But how do this ?

                          jsulmJ Offline
                          jsulmJ Offline
                          jsulm
                          Lifetime Qt Champion
                          wrote on last edited by
                          #26

                          @Damian7546 said in Create object in another object:

                          But how do this ?

                          Make outFrameQueue member variable instead of local variable.

                          https://forum.qt.io/topic/113070/qt-code-of-conduct

                          1 Reply Last reply
                          1
                          • D Offline
                            D Offline
                            Damian7546
                            wrote on last edited by
                            #27

                            sure!! Thank you !

                            1 Reply Last reply
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