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  4. [QtSerialPort] Simple example crashes

[QtSerialPort] Simple example crashes

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  • M Offline
    M Offline
    M4chin3
    wrote on last edited by
    #10

    kuzulis:

    Hi,

    1. I'm trying to use USB-to-Comport devices with a FTDI IC (FT232R). Here's a picture of my device mger:

    "Device manager screen (imgshack)":http://imageshack.us/a/img29/4827/mzma.png

    1. I can reproduce the same error without the lines of code you mentioned. I forgot about this: The error occurs in the head of the foreach loop within the static method "availablePorts()" of class QSerialPortInfo.

    2. I can reproduce the same error with the release branch version of QtSerialPort.

    [quote author="kuzulis" date="1371481349"]Hi M4chin3.

    Here at a forum already there was the same problem, but I can't find a this thread. It is strange. Solutions of this problem, certainly still aren't present because the reason is unclear.

    1. Whether your OS has serial ports? Give please a screenshot from Device Manager (with numbers and names of ports).

    2. Can you reproduce a problem without this code?

    @// Example use QSerialPort
    QSerialPort serial;
    serial.setPort(info);
    if (serial.open(QIODevice::ReadWrite))
    serial.close();
    }@

    1. Can you reproduce a problem with Release branch?

    https://qt.gitorious.org/qt/qtserialport/commits/release[/quote]

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    • M Offline
      M Offline
      M4chin3
      wrote on last edited by
      #11

      quickybr:

      I also got strawberry perl, so i tried your way with Active Perl on the WinXp machine.
      -> The QtSerialPort lib was compiled fine (same like with strawberry perl). I also could use it in Qt Creator but it didn't find any of my serial ports. I will check about this in detail tomorrow.

      Why WinXP machine and not the Win7 one iam actually working with?
      -> i dont have admin on the win7 machine. I have to wait for the IT guys untill tomorrow.
      :-/

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      • K Offline
        K Offline
        kuzulis
        Qt Champions 2020
        wrote on last edited by
        #12

        bq. Removed the Perl that I was using (strawberry Perl)
        Installed Active Perl (the last version)

        Hmm.. It is interesting, thx! May it is a cause of problem? Because I'm using Active perl and don't have a problem.

        Can anyone try to check with this difference of Perl?

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        • M Offline
          M Offline
          M4chin3
          wrote on last edited by
          #13

          IT department has to check the licences before installtion, so it might take a while. But i'll try as soon as possible.

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          • Q Offline
            Q Offline
            quickybr
            wrote on last edited by
            #14

            Yesterday I didn't have tried to communicate. But I tested now and I confirm, it's working properly

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            • M Offline
              M Offline
              M4chin3
              wrote on last edited by
              #15

              Hi everybody,

              finally i got ActivePerl installed on the Win7 machine. Sadly it didn't change anything for me :-(. I compiled and installed QtSerialPort both ways: via console and via QtCreator and tested it.

              The programm still crashes in the same behaviour as described before.

              This is the crash track in detail:
              main (QSerialPortInfo::availablePorts()) -> qserialportinfo_win.cpp;line 166 (QString s = devicePortName(deviceInfoSet, &deviceInfoData);) -> qserialportinfo_win.cpp;line 132 (QByteArray data(dataSize, 0);)

              The construction of the QByteArray fails somehow and this creates the Qt5Core.dll error. The question is why?

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              • M Offline
                M Offline
                M4chin3
                wrote on last edited by
                #16

                Hi,

                okay i' one step further:

                WinXP 32bit:
                Status:
                Couldn't find any serial ports but did not crash like Win7 Pro 64bit. QtSerialPort compiled with Strawberry Perl or ActivePerl didn't matter.

                Problem:
                Administrator priviliges are needed otherwise "::SetupDiEnumDeviceInfo(deviceInfoSet, index++, &deviceInfoData)" returns true but the &deviceInfoData is emtpy respectivly the device name is empty (QString s = devicePortName(deviceInfoSet, &deviceInfoData))

                I'll try to get administrator priviliges tomorrow to try this on Windows7. At least i know how the serial ports are searched on windows systems.

                Will this be changed? Otherwise users of my programm will also need administrator priviliges right? Wouldn't be that good.

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                • K Offline
                  K Offline
                  kuzulis
                  Qt Champions 2020
                  wrote on last edited by
                  #17

                  @M4chin3,

                  bq. The question is why?

                  I don't know. For a solution I need to reproduce at itself crash - but I can't.

                  bq. Otherwise users of my programm will also need administrator priviliges right?

                  No. Privileges of the administrator aren't required. Most likely you have any other restrictions on your user account.

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                  • M Offline
                    M Offline
                    M4chin3
                    wrote on last edited by
                    #18

                    Hello everyone,

                    in the last weeks i had no time for further investigation about the error. Today i opened the example project again, ran it and it works! I Didn't change anything in the code and my priviliges on this machine are the same than i posted the last time.

                    I assume that in the time i didn't touch the project the IT department did a windows update via their updatemanagement that fixed my problem. I'll contact them for a list of updates they did in this time. I hope i get a list from them. Maybe i find a patch that could be related to my error.

                    I don't have any other explanation for this.

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                    • A Offline
                      A Offline
                      artem_pisarenko
                      wrote on last edited by
                      #19

                      Similar issue.

                      Using QtSerialPort built from current 'stable' branch (50ab4d) causes simple example (from wiki) to crash in first QSerialPort::open() with segmentation fault (application terminates with exit code 255). Using QtSerialPort built from current 'release' branch (84df6e) works ok.

                      My setup is:
                      Win7 Pro x64
                      Qt 4.8.4

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                      • A Offline
                        A Offline
                        artem_pisarenko
                        wrote on last edited by
                        #20

                        Bisecting between revisions I got following results:

                        • da0c6b works ok
                        • 43f7c6 seems works ok but adds messages to debug output: "virtual void QSerialPort::close(): device not open"
                        • 50ab4d causes crash (as described in previous post)

                        (Tests was performed by reusing full rebuild cycle: <module build dir> mingw32-make clean, <module build dir> mingw32-make uninstall, clean <module build dir>, clean <app project>, run qmake on <app project>, ...)

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                        • K Offline
                          K Offline
                          kuzulis
                          Qt Champions 2020
                          wrote on last edited by
                          #21

                          Hi.

                          Yes, I confirm it. Thx.

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                          • K Offline
                            K Offline
                            kuzulis
                            Qt Champions 2020
                            wrote on last edited by
                            #22

                            Here a patch:

                            https://codereview.qt-project.org/#change,67801

                            please try it.

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                            • A Offline
                              A Offline
                              artem_pisarenko
                              wrote on last edited by
                              #23

                              Yes, it fixed issue.
                              (But there are still warnings since 43f7c6. Seems like QSerialPort destructor tries to do some finalizing work on already closed port.)

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                              • K Offline
                                K Offline
                                kuzulis
                                Qt Champions 2020
                                wrote on last edited by
                                #24

                                (But there are still warnings since 43f7c6. Seems like QSerialPort destructor tries to do some finalizing work on already closed port.)

                                It is a not problem.

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                                • D Offline
                                  D Offline
                                  djszapi
                                  wrote on last edited by
                                  #25

                                  @JBlackArty:

                                  https://codereview.qt-project.org/#change,67910

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