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Correct syntax to register object reference using qRegisterMetaType?

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  • JonBJ JonB

    @SPlatten
    The signal argument type is "OK", insofar as it would work OK with non-cross-thread direct connection connect()s. But the problem is that you are trying to use it when you need a queued connection. That is why you get the error message on the QObject::connect statement.

    SPlattenS Offline
    SPlattenS Offline
    SPlatten
    wrote on last edited by
    #15

    @JonB , thank you, I'll take a look.

    Kind Regards,
    Sy

    1 Reply Last reply
    0
    • SPlattenS SPlatten

      @kshegunov , I am using const QJsonObject& for my signal arguments, these are working, the only thing that is displayed in the Application Output is the message I've raised. I'm not experience any other problems, crashes or bugs.

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

      @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

      @kshegunov , I am using const QJsonObject& for my signal arguments, these are working, the only thing that is displayed in the Application Output is the message I've raised. I'm not experience any other problems, crashes or bugs.

      For the slots as well ?

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

      SPlattenS 1 Reply Last reply
      2
      • SGaistS SGaist

        @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

        @kshegunov , I am using const QJsonObject& for my signal arguments, these are working, the only thing that is displayed in the Application Output is the message I've raised. I'm not experience any other problems, crashes or bugs.

        For the slots as well ?

        SPlattenS Offline
        SPlattenS Offline
        SPlatten
        wrote on last edited by
        #17

        @SGaist Of course.

        Kind Regards,
        Sy

        1 Reply Last reply
        0
        • SPlattenS Offline
          SPlattenS Offline
          SPlatten
          wrote on last edited by
          #18

          Ok, I've now got rid of the warning, by going through all the QObject::connect calls and only using Qt::DirectionConnection where the signal and slot pointers are the same.

          Kind Regards,
          Sy

          JonBJ 1 Reply Last reply
          0
          • SPlattenS SPlatten

            Ok, I've now got rid of the warning, by going through all the QObject::connect calls and only using Qt::DirectionConnection where the signal and slot pointers are the same.

            JonBJ Offline
            JonBJ Offline
            JonB
            wrote on last edited by
            #19

            @SPlatten
            A lot of your questions are about threads. Are your connect()s' senders/receivers never in separate threads?

            SPlattenS 1 Reply Last reply
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            • JonBJ JonB

              @SPlatten
              A lot of your questions are about threads. Are your connect()s' senders/receivers never in separate threads?

              SPlattenS Offline
              SPlattenS Offline
              SPlatten
              wrote on last edited by
              #20

              @JonB , not for the ones where I've used Qt::DirectConnection

              Kind Regards,
              Sy

              1 Reply Last reply
              1
              • Christian EhrlicherC Offline
                Christian EhrlicherC Offline
                Christian Ehrlicher
                Lifetime Qt Champion
                wrote on last edited by
                #21

                @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

                not for the ones where I've used Qt::DirectConnection

                Then it's useless since then Qt::AutoConnection evaluates to Qt::DirectConnection. Specifying a connection type is not needed in most of the cases.

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

                SPlattenS 1 Reply Last reply
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                • Christian EhrlicherC Christian Ehrlicher

                  @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

                  not for the ones where I've used Qt::DirectConnection

                  Then it's useless since then Qt::AutoConnection evaluates to Qt::DirectConnection. Specifying a connection type is not needed in most of the cases.

                  SPlattenS Offline
                  SPlattenS Offline
                  SPlatten
                  wrote on last edited by
                  #22

                  @Christian-Ehrlicher , Well that's the only change I'm implemented and now there is no message, so perhaps this is something that needs looking at?

                  Kind Regards,
                  Sy

                  SGaistS Christian EhrlicherC kshegunovK 3 Replies Last reply
                  0
                  • SPlattenS SPlatten

                    @Christian-Ehrlicher , Well that's the only change I'm implemented and now there is no message, so perhaps this is something that needs looking at?

                    SGaistS Offline
                    SGaistS Offline
                    SGaist
                    Lifetime Qt Champion
                    wrote on last edited by
                    #23

                    @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

                    @Christian-Ehrlicher , Well that's the only change I'm implemented and now there is no message, so perhaps this is something that needs looking at?

                    For that a minimal compilable example would be needed.

                    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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                    • SPlattenS SPlatten

                      @Christian-Ehrlicher , Well that's the only change I'm implemented and now there is no message, so perhaps this is something that needs looking at?

                      Christian EhrlicherC Offline
                      Christian EhrlicherC Offline
                      Christian Ehrlicher
                      Lifetime Qt Champion
                      wrote on last edited by
                      #24

                      @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

                      so perhaps this is something that needs looking at?

                      This means that there is a thread context switch somewhere even you tell us it isn't.

                      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
                      • SPlattenS SPlatten

                        @Christian-Ehrlicher , Well that's the only change I'm implemented and now there is no message, so perhaps this is something that needs looking at?

                        kshegunovK Offline
                        kshegunovK Offline
                        kshegunov
                        Moderators
                        wrote on last edited by
                        #25

                        @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

                        @Christian-Ehrlicher , Well that's the only change I'm implemented and now there is no message, so perhaps this is something that needs looking at?

                        Run with QT_FATAL_WARNINGS=1 as an environment variable and extract the stack trace, then you will have leveraged your debugger to show you exactly where you're passing a reference between threads.

                        Read and abide by the Qt Code of Conduct

                        SPlattenS 1 Reply Last reply
                        2
                        • kshegunovK kshegunov

                          @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

                          @Christian-Ehrlicher , Well that's the only change I'm implemented and now there is no message, so perhaps this is something that needs looking at?

                          Run with QT_FATAL_WARNINGS=1 as an environment variable and extract the stack trace, then you will have leveraged your debugger to show you exactly where you're passing a reference between threads.

                          SPlattenS Offline
                          SPlattenS Offline
                          SPlatten
                          wrote on last edited by
                          #26

                          @kshegunov said in Correct syntax to register object reference using qRegisterMetaType?:

                          QT_FATAL_WARNINGS=1

                          I've opened both .pro files and added that line, then cleaned and rebuilt, the applications have been running for several minutes, nothing to report, no issues.

                          Kind Regards,
                          Sy

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                          0
                          • SGaistS Offline
                            SGaistS Offline
                            SGaist
                            Lifetime Qt Champion
                            wrote on last edited by
                            #27

                            It's an environnement variable, not a define.

                            You have to set it in the Run tab of the Project panel.

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

                            SPlattenS 1 Reply Last reply
                            1
                            • SGaistS SGaist

                              It's an environnement variable, not a define.

                              You have to set it in the Run tab of the Project panel.

                              SPlattenS Offline
                              SPlattenS Offline
                              SPlatten
                              wrote on last edited by
                              #28

                              @SGaist , Yes, just googled it and then added as environment variable:

                              export QT_FATAL_WARNINGS=1
                              

                              Then restarted, same, not seeing anything additional.

                              Kind Regards,
                              Sy

                              1 Reply Last reply
                              0
                              • SGaistS Offline
                                SGaistS Offline
                                SGaist
                                Lifetime Qt Champion
                                wrote on last edited by
                                #29

                                Restarted what ?
                                How are you currently running your application ?

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

                                SPlattenS 1 Reply Last reply
                                1
                                • SGaistS SGaist

                                  Restarted what ?
                                  How are you currently running your application ?

                                  SPlattenS Offline
                                  SPlattenS Offline
                                  SPlatten
                                  wrote on last edited by
                                  #30

                                  @SGaist , I launch the processes with Qt Creator in debug mode, using two separate instances of Qt Creator.

                                  Kind Regards,
                                  Sy

                                  1 Reply Last reply
                                  0
                                  • SGaistS Offline
                                    SGaistS Offline
                                    SGaist
                                    Lifetime Qt Champion
                                    wrote on last edited by SGaist
                                    #31

                                    Did you check the environment variables in the Run part of the Project Panel to ensure it's properly set ?

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

                                    SPlattenS 1 Reply Last reply
                                    1
                                    • SGaistS SGaist

                                      Did you check the environment variables in the Run part of the Project Panel to ensure it's properly set ?

                                      SPlattenS Offline
                                      SPlattenS Offline
                                      SPlatten
                                      wrote on last edited by
                                      #32

                                      @SGaist , I checked in a terminal, I don't know how or where to "Run part of the Project Panel" ?

                                      Kind Regards,
                                      Sy

                                      jsulmJ 1 Reply Last reply
                                      0
                                      • SPlattenS SPlatten

                                        @SGaist , I checked in a terminal, I don't know how or where to "Run part of the Project Panel" ?

                                        jsulmJ Offline
                                        jsulmJ Offline
                                        jsulm
                                        Lifetime Qt Champion
                                        wrote on last edited by jsulm
                                        #33

                                        @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

                                        I don't know how or where to "Run part of the Project Panel" ?

                                        Easy to find actually.
                                        Left pane: Projects -> Build & Run -> Run...

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

                                        SPlattenS 1 Reply Last reply
                                        2
                                        • jsulmJ jsulm

                                          @SPlatten said in Correct syntax to register object reference using qRegisterMetaType?:

                                          I don't know how or where to "Run part of the Project Panel" ?

                                          Easy to find actually.
                                          Left pane: Projects -> Build & Run -> Run...

                                          SPlattenS Offline
                                          SPlattenS Offline
                                          SPlatten
                                          wrote on last edited by
                                          #34

                                          @jsulm , thank you, added it now, building now.

                                          Kind Regards,
                                          Sy

                                          1 Reply Last reply
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