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How make QIODevice::writeData work asynchronously?

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  • SGaistS Offline
    SGaistS Offline
    SGaist
    Lifetime Qt Champion
    wrote on last edited by
    #4

    Hi,

    The QObject::moveToThread function might be what you need.

    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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    • F Offline
      F Offline
      fpartl
      wrote on last edited by
      #5

      Thank you for reply. I dont know if I should move to thred whole class with QAudioInput a QIODevice objects or just QIODevice. I will try something.

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      • SGaistS Offline
        SGaistS Offline
        SGaist
        Lifetime Qt Champion
        wrote on last edited by
        #6

        Usually you move the whole object, don't forget to parent things correctly to have everything moved properly.

        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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        • F Offline
          F Offline
          fpartl
          wrote on last edited by
          #7

          I have done the work. I have created the the AudioWorker class witch inherits QObject. Then I maked QAudioInput and QIODevice in here and I make a forward of signals from QIODevice to catch calculated data. I moved AudioWorker to QThread and pressed the Run button. But program crash on segmentation fault in QIODevice even if I comment the whole code in writeData method.

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          • SGaistS Offline
            SGaistS Offline
            SGaist
            Lifetime Qt Champion
            wrote on last edited by
            #8

            Without the code and the backtrace, it's pretty much Crystal Ball Debugging so here goes: did you check that you have everything initialised properly before using ?

            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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            • F Offline
              F Offline
              fpartl
              wrote on last edited by
              #9

              Ou, I am sorry. The code is on GitHub. I wrote the AudioWorker class and program fails after I close the MainWindow with

              The program has unexpectedly finished.
              C:\Users\frant\QtProjects\build-PocketEar-Desktop_Qt_5_8_0_MinGW_32bit-Debug\debug\PocketEar.exe crashed.
              

              In the AudioWorker there is instances of QAudioInput and QIODevice(MFCCPerformer).
              In the debug mode I got segmentation fault after MainWindow close on line 28 in AudioWorker (audioInput->suspend()). I think I am wrong with a closing of the thread. Thank for help.

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              • SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #10

                Do you have a complete stack trace ?

                Note that you are doing a double delete with audioInput and mfcc. Both of them have a parent so they will be delete when AudioWorker gets deleted.

                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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                • F Offline
                  F Offline
                  fpartl
                  wrote on last edited by
                  #11

                  Here is a stack trace after failure. I really appreciate your help. I am new in this problematics.

                  Stack trace

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                  • F Offline
                    F Offline
                    fpartl
                    wrote on last edited by
                    #12

                    I figured it out! serverStateChanged call pause method on alredy destroyed object. Now it works. What a thing! Thank you for help! :-)

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                    • SGaistS Offline
                      SGaistS Offline
                      SGaist
                      Lifetime Qt Champion
                      wrote on last edited by
                      #13

                      You're welcome !

                      Since you have found the error, please mark the thread as solved using the "Topic Tools" button so that other forum users may know a solution has been found :)

                      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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