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Qt6 Windows slower than Qt6 Ubuntu

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ubuntuwindows 10 instmsvcgccqt6
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  • JonBJ JonB

    @Joe-von-Habsburg
    No, compiler is not going to make any difference when fetching data over a network and it's taking hundreds of milliseconds.

    J Offline
    J Offline
    Joe von Habsburg
    wrote on last edited by
    #10

    @JonB

    I wrote basic program just taking data. (Because I suspect other code lines slow me). I saw same output.

    Can you give me code example for get request ?

    1 Reply Last reply
    0
    • JonBJ JonB

      @Joe-von-Habsburg
      If you are calling this multiple times at least correct so as not to leak the QNetworkReply. Probably irrelevant, but just in case.

      How do timings compare on each platform quite outside of a Qt program?

      JonBJ Online
      JonBJ Online
      JonB
      wrote on last edited by
      #11

      @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

      How do timings compare on each platform quite outside of a Qt program?

      J 1 Reply Last reply
      0
      • JonBJ JonB

        @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

        How do timings compare on each platform quite outside of a Qt program?

        J Offline
        J Offline
        Joe von Habsburg
        wrote on last edited by
        #12

        @JonB I watched graphic speed

        jsulmJ 1 Reply Last reply
        0
        • J Joe von Habsburg

          @JonB I watched graphic speed

          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by
          #13

          @Joe-von-Habsburg You should read more carefully what others write. What @JonB suggested is that you try to get the data with a non Qt application on both platforms to see whether the behaviour is the same or not...

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

          J 1 Reply Last reply
          0
          • jsulmJ jsulm

            @Joe-von-Habsburg You should read more carefully what others write. What @JonB suggested is that you try to get the data with a non Qt application on both platforms to see whether the behaviour is the same or not...

            J Offline
            J Offline
            Joe von Habsburg
            wrote on last edited by
            #14

            @jsulm I used javascript for get request.

            const deneme = async() => {
                while(true){
                    var date1 = new Date();
                
                    var res = await fetch('http://localhost:54664/sample')
                    var data = await res.json();
                    console.log("sample len : ",data.samples[0].length)
                
                    var date2 = new Date();
                
                    var res2 = await fetch('http://localhost:54665/sample')
                    var data2 = await res2.json();
                    console.log("sample len : ",data2.samples[0].length)
                
                    var date3 = new Date();
                
                    console.log("sample : ", date2-date1, " - iq : ", date3 - date2, " - time : ", date3 - date1);
                }
            }
            
            
            deneme();
            

            I saw same times between ubuntu and windows (90ms).
            I think the problem is in windows Qt. Any idea ?

            jsulmJ 1 Reply Last reply
            0
            • J Joe von Habsburg

              @jsulm I used javascript for get request.

              const deneme = async() => {
                  while(true){
                      var date1 = new Date();
                  
                      var res = await fetch('http://localhost:54664/sample')
                      var data = await res.json();
                      console.log("sample len : ",data.samples[0].length)
                  
                      var date2 = new Date();
                  
                      var res2 = await fetch('http://localhost:54665/sample')
                      var data2 = await res2.json();
                      console.log("sample len : ",data2.samples[0].length)
                  
                      var date3 = new Date();
                  
                      console.log("sample : ", date2-date1, " - iq : ", date3 - date2, " - time : ", date3 - date1);
                  }
              }
              
              
              deneme();
              

              I saw same times between ubuntu and windows (90ms).
              I think the problem is in windows Qt. Any idea ?

              jsulmJ Offline
              jsulmJ Offline
              jsulm
              Lifetime Qt Champion
              wrote on last edited by
              #15

              @Joe-von-Habsburg You should try to do your networking properly: without local event loops. Qt is asynchronous.

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

              Christian EhrlicherC 1 Reply Last reply
              0
              • jsulmJ jsulm

                @Joe-von-Habsburg You should try to do your networking properly: without local event loops. Qt is asynchronous.

                Christian EhrlicherC Offline
                Christian EhrlicherC Offline
                Christian Ehrlicher
                Lifetime Qt Champion
                wrote on last edited by
                #16

                ... And you should/must not recreate the QNetworkAcceesManager every time.

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

                J 2 Replies Last reply
                4
                • Christian EhrlicherC Christian Ehrlicher

                  ... And you should/must not recreate the QNetworkAcceesManager every time.

                  J Offline
                  J Offline
                  Joe von Habsburg
                  wrote on last edited by
                  #17

                  @Christian-Ehrlicher said in Qt6 Windows slower than Qt6 Ubuntu:

                  And you should/must not recreate the QNetworkAcceesManager every time.

                  This work for me. Thank you so much :)

                  1 Reply Last reply
                  0
                  • Christian EhrlicherC Christian Ehrlicher

                    ... And you should/must not recreate the QNetworkAcceesManager every time.

                    J Offline
                    J Offline
                    Joe von Habsburg
                    wrote on last edited by
                    #18

                    @Christian-Ehrlicher

                    I have another question. I received some times between ubuntu and windows (65ms). Everything is ok. But, sometimes windows rising 350ms for one packet. In ubuntu just max 80ms.

                    QByteArray DataReceiver::getData(int port)
                    {
                        QString url = QString("http://localhost:%1/sample").arg(port);
                        _apiUrl.setUrl(url);
                        _request.setUrl(_apiUrl);
                        _reply = _manager.get(_request);
                        connect(_reply, &QNetworkReply::finished, &_loop, &QEventLoop::quit);
                        _loop.exec();
                        if (_reply->error() == QNetworkReply::NoError) {
                            QByteArray responseData = _reply->readAll();
                            _reply->deleteLater();
                            return responseData;
                        } else {
                            QString _error = tr("Error");
                            QString _spectrum_error = tr("Spectrum error.");
                            QMessageBox::critical(nullptr, _error, _spectrum_error);
                            stop();
                        }
                        _reply->deleteLater();
                        return NULL;
                    }
                    

                    Do you know, why it's rising ? What can I do another, after take data ?

                    J 1 Reply Last reply
                    0
                    • J Joe von Habsburg

                      @Christian-Ehrlicher

                      I have another question. I received some times between ubuntu and windows (65ms). Everything is ok. But, sometimes windows rising 350ms for one packet. In ubuntu just max 80ms.

                      QByteArray DataReceiver::getData(int port)
                      {
                          QString url = QString("http://localhost:%1/sample").arg(port);
                          _apiUrl.setUrl(url);
                          _request.setUrl(_apiUrl);
                          _reply = _manager.get(_request);
                          connect(_reply, &QNetworkReply::finished, &_loop, &QEventLoop::quit);
                          _loop.exec();
                          if (_reply->error() == QNetworkReply::NoError) {
                              QByteArray responseData = _reply->readAll();
                              _reply->deleteLater();
                              return responseData;
                          } else {
                              QString _error = tr("Error");
                              QString _spectrum_error = tr("Spectrum error.");
                              QMessageBox::critical(nullptr, _error, _spectrum_error);
                              stop();
                          }
                          _reply->deleteLater();
                          return NULL;
                      }
                      

                      Do you know, why it's rising ? What can I do another, after take data ?

                      J Offline
                      J Offline
                      Joe von Habsburg
                      wrote on last edited by
                      #19

                      @Joe-von-Habsburg I found the reason. Thanks a lot :) <3

                      V 1 Reply Last reply
                      0
                      • J Joe von Habsburg

                        @Joe-von-Habsburg I found the reason. Thanks a lot :) <3

                        V Offline
                        V Offline
                        Volker75
                        wrote on last edited by
                        #20

                        @Joe-von-Habsburg And what was the reason? Windows defender?

                        J 1 Reply Last reply
                        0
                        • V Volker75

                          @Joe-von-Habsburg And what was the reason? Windows defender?

                          J Offline
                          J Offline
                          Joe von Habsburg
                          wrote on last edited by Joe von Habsburg
                          #21

                          @Volker75 said in Qt6 Windows slower than Qt6 Ubuntu:

                          And what was the reason? Windows defender?

                          another networkmanager.....

                          @Christian-Ehrlicher , @JonB , @jsulm

                          Hi guys, I need your help. When I run the my program (only data receive) after 30min, my ram will be 20gb. It's increase always. I tested it in Ubuntu and Windows and I saw same thing. What should I do after take data?

                          QByteArray DataReceiver::getData(int port)
                          {
                              QString url = QString("http://localhost:%1/sample").arg(port);
                              _apiUrl.setUrl(url);
                              _request.setUrl(_apiUrl);
                              reply = _manager.get(_request);
                              connect(reply, &QNetworkReply::finished, &_loop, &QEventLoop::quit);
                              _loop.exec();
                              if (reply->error() == QNetworkReply::NoError) {
                                  QByteArray responseData = reply->readAll();
                                  reply->deleteLater();
                                  return  responseData;
                              } else {
                                  QString _error = tr("Error");
                                  QString _spectrum_error = tr("Spectrum error.");
                                  QMessageBox::critical(nullptr, _error, _spectrum_error);
                                  stop();
                              }
                              reply->deleteLater();
                              return {};
                          }
                          

                          if I use my code like that :

                          QByteArray DataReceiver::getData(int port)
                          {
                              QString url = QString("http://localhost:%1/sample").arg(port);
                              QUrl _apiUrl(url);
                              QNetworkRequest _request(_apiUrl);
                              QEventLoop _loop;
                              QNetworkAccessManager _manager;
                              QNetworkReply *reply = _manager.get(_request);
                              connect(reply, &QNetworkReply::finished, &_loop, &QEventLoop::quit);
                              _loop.exec();
                              if (reply->error() == QNetworkReply::NoError) {
                                  QByteArray responseData = reply->readAll();
                                  reply->deleteLater();
                                  return  responseData;
                              } else {
                                  QString _error = tr("Error");
                                  QString _spectrum_error = tr("Spectrum error.");
                                  QMessageBox::critical(nullptr, _error, _spectrum_error);
                                  stop();
                              }
                              reply->deleteLater();
                              return {};
                          }
                          

                          Memory will not rise but response time slow....

                          JonBJ 1 Reply Last reply
                          0
                          • J Joe von Habsburg

                            @Volker75 said in Qt6 Windows slower than Qt6 Ubuntu:

                            And what was the reason? Windows defender?

                            another networkmanager.....

                            @Christian-Ehrlicher , @JonB , @jsulm

                            Hi guys, I need your help. When I run the my program (only data receive) after 30min, my ram will be 20gb. It's increase always. I tested it in Ubuntu and Windows and I saw same thing. What should I do after take data?

                            QByteArray DataReceiver::getData(int port)
                            {
                                QString url = QString("http://localhost:%1/sample").arg(port);
                                _apiUrl.setUrl(url);
                                _request.setUrl(_apiUrl);
                                reply = _manager.get(_request);
                                connect(reply, &QNetworkReply::finished, &_loop, &QEventLoop::quit);
                                _loop.exec();
                                if (reply->error() == QNetworkReply::NoError) {
                                    QByteArray responseData = reply->readAll();
                                    reply->deleteLater();
                                    return  responseData;
                                } else {
                                    QString _error = tr("Error");
                                    QString _spectrum_error = tr("Spectrum error.");
                                    QMessageBox::critical(nullptr, _error, _spectrum_error);
                                    stop();
                                }
                                reply->deleteLater();
                                return {};
                            }
                            

                            if I use my code like that :

                            QByteArray DataReceiver::getData(int port)
                            {
                                QString url = QString("http://localhost:%1/sample").arg(port);
                                QUrl _apiUrl(url);
                                QNetworkRequest _request(_apiUrl);
                                QEventLoop _loop;
                                QNetworkAccessManager _manager;
                                QNetworkReply *reply = _manager.get(_request);
                                connect(reply, &QNetworkReply::finished, &_loop, &QEventLoop::quit);
                                _loop.exec();
                                if (reply->error() == QNetworkReply::NoError) {
                                    QByteArray responseData = reply->readAll();
                                    reply->deleteLater();
                                    return  responseData;
                                } else {
                                    QString _error = tr("Error");
                                    QString _spectrum_error = tr("Spectrum error.");
                                    QMessageBox::critical(nullptr, _error, _spectrum_error);
                                    stop();
                                }
                                reply->deleteLater();
                                return {};
                            }
                            

                            Memory will not rise but response time slow....

                            JonBJ Online
                            JonBJ Online
                            JonB
                            wrote on last edited by
                            #22

                            @Joe-von-Habsburg
                            Is the difference due to the QNetworkAccessManager _manager; or to the QNetworkReply *reply = _manager.get(_request);?
                            In the bad case you might connect to reply->destroyed() to make sure it is indeed getting freed.

                            J 1 Reply Last reply
                            0
                            • JonBJ JonB

                              @Joe-von-Habsburg
                              Is the difference due to the QNetworkAccessManager _manager; or to the QNetworkReply *reply = _manager.get(_request);?
                              In the bad case you might connect to reply->destroyed() to make sure it is indeed getting freed.

                              J Offline
                              J Offline
                              Joe von Habsburg
                              wrote on last edited by Joe von Habsburg
                              #23

                              @JonB

                              According to my tests, if I rebuild the NetworkManager, my memory usage does not increase. But this time my receiving time is slowing down.

                              If I do not recreate the NetworkManager, my reception time decreases but memory usage increases.

                              connect(reply, &QNetworkReply::destroyed, this, &DataReceiver::replyDeleted);
                              

                              it's work, reply deleted

                              JonBJ J 2 Replies Last reply
                              0
                              • J Joe von Habsburg

                                @JonB

                                According to my tests, if I rebuild the NetworkManager, my memory usage does not increase. But this time my receiving time is slowing down.

                                If I do not recreate the NetworkManager, my reception time decreases but memory usage increases.

                                connect(reply, &QNetworkReply::destroyed, this, &DataReceiver::replyDeleted);
                                

                                it's work, reply deleted

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

                                @Joe-von-Habsburg
                                In that case please replace the second one's QNetworkReply *reply = _manager.get(_request); with the first one's reply = _manager.get(_request); (I assume reply is a member variable, this->reply) and confirm. Then the only difference is the local QNetworkAccessManager _manager versus a class member one.

                                1 Reply Last reply
                                0
                                • J Joe von Habsburg

                                  @JonB

                                  According to my tests, if I rebuild the NetworkManager, my memory usage does not increase. But this time my receiving time is slowing down.

                                  If I do not recreate the NetworkManager, my reception time decreases but memory usage increases.

                                  connect(reply, &QNetworkReply::destroyed, this, &DataReceiver::replyDeleted);
                                  

                                  it's work, reply deleted

                                  J Offline
                                  J Offline
                                  Joe von Habsburg
                                  wrote on last edited by Joe von Habsburg
                                  #25

                                  @Joe-von-Habsburg said in Qt6 Windows slower than Qt6 Ubuntu:

                                  connect(reply, &QNetworkReply::destroyed, this, &DataReceiver::replyDeleted);

                                  sorry for that. this is work only when I stop my while loop. How can force it ?

                                  @Joe-von-Habsburg said in Qt6 Windows slower than Qt6 Ubuntu:

                                   void DataReceiver::start()
                                   {
                                       _connection++;
                                       if(_connection > 1)
                                           return;
                                   
                                       qDebug() << "Starting take data";
                                       _takeData = true;
                                       while(_takeData){
                                           QDateTime time1 = QDateTime::currentDateTime();
                                           _sample = getData(54664);
                                           QDateTime time3 = QDateTime::currentDateTime();
                                           if(_takeIQData)
                                               _iq = getData(54665);
                                           QDateTime time2 = QDateTime::currentDateTime();
                                           qDebug() << "sample : " << time3 - time1 << " iq : " << time2 - time3 << "time :  << time2 - time1;
                                          emit sendData(_sample, _iq);
                                       }
                                       qDebug() << "Finished taking data";
                                   }
                                  
                                  

                                  @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

                                  n that case please replace the second one's QNetworkReply *reply = _manager.get(_request); with the first one's reply = _manager.get(_request); (I assume reply is a member variable, this->reply) and confirm. Then the only difference is the local QNetworkAccessManager _manager versus a class member one.

                                  I change it.
                                  _reply and _manager class member now

                                  QByteArray DataReceiver::getData(int port)
                                  {
                                      QString url = QString("http://localhost:%1/sample").arg(port);
                                      QUrl _apiUrl(url);
                                      QNetworkRequest _request(_apiUrl);
                                      QEventLoop _loop;
                                      _reply = _manager.get(_request);
                                      connect(_reply, &QNetworkReply::finished, &_loop, &QEventLoop::quit);
                                      connect(_reply, &QNetworkReply::destroyed, this, &DataReceiver::replyDeleted);
                                      _loop.exec();
                                      if (_reply->error() == QNetworkReply::NoError) {
                                          QByteArray responseData = _reply->readAll();
                                          _reply->deleteLater();
                                          return  responseData;
                                      } else {
                                          QString _error = tr("Error");
                                          QString _spectrum_error = tr("Spectrum error.");
                                          QMessageBox::critical(nullptr, _error, _spectrum_error);
                                          stop();
                                      }
                                      _reply->deleteLater();
                                      return {};
                                  }
                                  

                                  The problem still exists.

                                  I think lots of reply are created and they only delete I stop my loop.

                                  JonBJ 1 Reply Last reply
                                  0
                                  • J Joe von Habsburg

                                    @Joe-von-Habsburg said in Qt6 Windows slower than Qt6 Ubuntu:

                                    connect(reply, &QNetworkReply::destroyed, this, &DataReceiver::replyDeleted);

                                    sorry for that. this is work only when I stop my while loop. How can force it ?

                                    @Joe-von-Habsburg said in Qt6 Windows slower than Qt6 Ubuntu:

                                     void DataReceiver::start()
                                     {
                                         _connection++;
                                         if(_connection > 1)
                                             return;
                                     
                                         qDebug() << "Starting take data";
                                         _takeData = true;
                                         while(_takeData){
                                             QDateTime time1 = QDateTime::currentDateTime();
                                             _sample = getData(54664);
                                             QDateTime time3 = QDateTime::currentDateTime();
                                             if(_takeIQData)
                                                 _iq = getData(54665);
                                             QDateTime time2 = QDateTime::currentDateTime();
                                             qDebug() << "sample : " << time3 - time1 << " iq : " << time2 - time3 << "time :  << time2 - time1;
                                            emit sendData(_sample, _iq);
                                         }
                                         qDebug() << "Finished taking data";
                                     }
                                    
                                    

                                    @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

                                    n that case please replace the second one's QNetworkReply *reply = _manager.get(_request); with the first one's reply = _manager.get(_request); (I assume reply is a member variable, this->reply) and confirm. Then the only difference is the local QNetworkAccessManager _manager versus a class member one.

                                    I change it.
                                    _reply and _manager class member now

                                    QByteArray DataReceiver::getData(int port)
                                    {
                                        QString url = QString("http://localhost:%1/sample").arg(port);
                                        QUrl _apiUrl(url);
                                        QNetworkRequest _request(_apiUrl);
                                        QEventLoop _loop;
                                        _reply = _manager.get(_request);
                                        connect(_reply, &QNetworkReply::finished, &_loop, &QEventLoop::quit);
                                        connect(_reply, &QNetworkReply::destroyed, this, &DataReceiver::replyDeleted);
                                        _loop.exec();
                                        if (_reply->error() == QNetworkReply::NoError) {
                                            QByteArray responseData = _reply->readAll();
                                            _reply->deleteLater();
                                            return  responseData;
                                        } else {
                                            QString _error = tr("Error");
                                            QString _spectrum_error = tr("Spectrum error.");
                                            QMessageBox::critical(nullptr, _error, _spectrum_error);
                                            stop();
                                        }
                                        _reply->deleteLater();
                                        return {};
                                    }
                                    

                                    The problem still exists.

                                    I think lots of reply are created and they only delete I stop my loop.

                                    JonBJ Online
                                    JonBJ Online
                                    JonB
                                    wrote on last edited by
                                    #26

                                    @Joe-von-Habsburg said in Qt6 Windows slower than Qt6 Ubuntu:

                                    I think lots of reply are created and they only delete I stop my loop.

                                    I do not follow this. One reply per _manager.get(_request), and you have checked that is getting destroyed.

                                    Supposedly, the only difference now is that in good case you create and destroy a local QNetworkAccessManager _manager each time (hence slower) while in bad case you reuse member variable. Right?

                                    In that case can only suggest you try playing with stuff to see if it makes any difference in the bad case. QNAM has a couple of caches you can clear (see docs), try those. Try calling its setAutoDeleteReplies(true). Try making the member variable a QNetworkAccessManager *_manager which you new and deleteLater() or delete and instead create a new one in the member variable each time its destroyed for use next time. That would "emulate" having it as a local variable which gets automatically created & destroyed in the good case.

                                    Other than that I am out of ideas. maybe someone expert will comment.

                                    J 2 Replies Last reply
                                    0
                                    • JonBJ JonB

                                      @Joe-von-Habsburg said in Qt6 Windows slower than Qt6 Ubuntu:

                                      I think lots of reply are created and they only delete I stop my loop.

                                      I do not follow this. One reply per _manager.get(_request), and you have checked that is getting destroyed.

                                      Supposedly, the only difference now is that in good case you create and destroy a local QNetworkAccessManager _manager each time (hence slower) while in bad case you reuse member variable. Right?

                                      In that case can only suggest you try playing with stuff to see if it makes any difference in the bad case. QNAM has a couple of caches you can clear (see docs), try those. Try calling its setAutoDeleteReplies(true). Try making the member variable a QNetworkAccessManager *_manager which you new and deleteLater() or delete and instead create a new one in the member variable each time its destroyed for use next time. That would "emulate" having it as a local variable which gets automatically created & destroyed in the good case.

                                      Other than that I am out of ideas. maybe someone expert will comment.

                                      J Offline
                                      J Offline
                                      Joe von Habsburg
                                      wrote on last edited by
                                      #27

                                      @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

                                      One reply per _manager.get(_request), and you have checked that is getting destroyed.

                                      I can't delete _reply after get data.

                                      _reply->deleteLater();
                                      

                                      I used connect function, I saw this result: when I stop loop, _replys will be deleted (lots of delete).

                                      connect(_reply, &QNetworkReply::destroyed, this, &DataReceiver::replyDeleted);
                                      void DataReceiver::replyDeleted()
                                      {
                                          qDebug() << "reply deleted.";
                                      }
                                      

                                      Result : 500409cc-80cf-486c-a0d2-cf80d7040a0a-image.png

                                      @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

                                      Supposedly, the only difference now is that in good case you create and destroy a local QNetworkAccessManager _manager each time (hence slower) while in bad case you reuse member variable. Right?

                                      Yes you right, if I do not use as local member (_manager), response time slow, but I use as local member, memory leak.

                                      @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

                                      ry calling its setAutoDeleteReplies(true). Try making the member variable a QNetworkAccessManager *_manager which you new and deleteLater()

                                      QByteArray DataReceiver::getData(int port)
                                      {
                                          QString url = QString("http://localhost:%1/sample").arg(port);
                                          QUrl _apiUrl(url);
                                          QNetworkRequest _request(_apiUrl);
                                          QEventLoop _loop;
                                          _manager = new QNetworkAccessManager();
                                          _manager->setAutoDeleteReplies(true);
                                          _reply = _manager->get(_request);
                                          connect(_reply, &QNetworkReply::finished, &_loop, &QEventLoop::quit);
                                          connect(_reply, &QNetworkReply::destroyed, this, &DataReceiver::replyDeleted);
                                          _loop.exec();
                                          if (_reply->error() == QNetworkReply::NoError) {
                                              QByteArray responseData = _reply->readAll();
                                              _reply->deleteLater();
                                              _manager->deleteLater();
                                              return  responseData;
                                          } else {
                                              QString _error = tr("Error");
                                              QString _spectrum_error = tr("Spectrum error.");
                                              QMessageBox::critical(nullptr, _error, _spectrum_error);
                                              stop();
                                          }
                                          _reply->deleteLater();
                                          return {};
                                      }
                                      

                                      I added them my function, but now slow time and memory leak exist together.

                                      @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

                                      Other than that I am out of ideas. maybe someone expert will comment.

                                      Thank you, Anyone can help me, I will be honered.

                                      1 Reply Last reply
                                      0
                                      • JonBJ JonB

                                        @Joe-von-Habsburg said in Qt6 Windows slower than Qt6 Ubuntu:

                                        I think lots of reply are created and they only delete I stop my loop.

                                        I do not follow this. One reply per _manager.get(_request), and you have checked that is getting destroyed.

                                        Supposedly, the only difference now is that in good case you create and destroy a local QNetworkAccessManager _manager each time (hence slower) while in bad case you reuse member variable. Right?

                                        In that case can only suggest you try playing with stuff to see if it makes any difference in the bad case. QNAM has a couple of caches you can clear (see docs), try those. Try calling its setAutoDeleteReplies(true). Try making the member variable a QNetworkAccessManager *_manager which you new and deleteLater() or delete and instead create a new one in the member variable each time its destroyed for use next time. That would "emulate" having it as a local variable which gets automatically created & destroyed in the good case.

                                        Other than that I am out of ideas. maybe someone expert will comment.

                                        J Offline
                                        J Offline
                                        Joe von Habsburg
                                        wrote on last edited by Joe von Habsburg
                                        #28

                                        @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

                                        setAutoDeleteReplies(true)

                                        this is crashed my program when I do something.

                                        if I do it :

                                        _manager.setAutoDeleteReplies(true);
                                        

                                        memory and speed ok, but program crashed anytime , when I do anything. because reply deleted. why ?

                                        JonBJ 1 Reply Last reply
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                                        • J Joe von Habsburg

                                          @JonB said in Qt6 Windows slower than Qt6 Ubuntu:

                                          setAutoDeleteReplies(true)

                                          this is crashed my program when I do something.

                                          if I do it :

                                          _manager.setAutoDeleteReplies(true);
                                          

                                          memory and speed ok, but program crashed anytime , when I do anything. because reply deleted. why ?

                                          JonBJ Online
                                          JonBJ Online
                                          JonB
                                          wrote on last edited by
                                          #29

                                          @Joe-von-Habsburg
                                          I would guess you need to not delete it yourself now (_reply->deleteLater()) since it is being auto-deleted on QNetworkReply::finished?

                                          However if it is being auto-deleted on finished then, because you do _loop.exec(); which waits for finished I would guess you can no longer do _reply->readAll() after the loop, that sounds like crash. You could instead do your data reading inside the loop instead of afterwards.

                                          I really don't know, and have never used any of this stuff :) It was suggestions for narrowing down where the "leakage" might be. But you need someone else if you need someone who truly knows about it.

                                          J 1 Reply Last reply
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