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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Great! The issues are fixed! Thanks!<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">The updated example is attached. I’ll try implement it in my code.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Christian<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">Von:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Barry [mailto:barry@barrys-emacs.org]
<br>
<b>Gesendet:</b> Montag, 12. März 2018 23:03<br>
<b>An:</b> Christian Schulze <c.schulze@tlk-therm</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">o.com><br>
<b>Cc:</b> Florian Bruhin <me@the-compiler.org>; pyqt@riverbankcomputing.com<br>
<b>Betreff:</b> Re: [PyQt] Multithreaded Update of the QStandardItemModel Data<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The trick you need is that you can send a signal from a non-main thread to the gui main-thread.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">In response to the signal you update the model. Put all the information that you need as the signal arg or args.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I use this idea in scm-workbench to sync the ui to background changes.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Barry<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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On 12 Mar 2018, at 21:52, Christian Schulze <<a href="mailto:c.schulze@tlk-thermo.com">c.schulze@tlk-thermo.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Hi Florian,</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">I need to update many items continuously. Several rows are updated at least once per second. For some use cases I have
20000 rows in total. I prepared all the data (new/modified/removed items), so that hardly any calculation is done in the main thread.</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">However, the main thead seems to be blocked for too long. The GUI seems to freeze for a short moment when I update the
data. This is really annoying when you’re working with the application and I’d like to fix that.</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">I had expected that I’m allowed to modify the item model, since the GUI thread only reads data. I don’t care if an intermediate
state is displayed.</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">So I need to implement my own threadsafe item model? Is any python based item model implementation threadsafe due to the
GIL? Is the interaction of python and C++ fast enough to do this?</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Thanks,</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Christian</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"> </span><o:p></o:p></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">Von:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Florian Bruhin [<a href="mailto:me@the-compiler.org">mailto:me@the-compiler.org</a>]
<br>
<b>Gesendet:</b> Montag, 12. März 2018 22:13<br>
<b>An:</b> Christian Schulze <<a href="mailto:c.schulze@tlk-thermo.com">c.schulze@tlk-thermo.com</a>><br>
<b>Cc:</b> <a href="mailto:pyqt@riverbankcomputing.com">pyqt@riverbankcomputing.com</a><br>
<b>Betreff:</b> Re: [PyQt] Multithreaded Update of the QStandardItemModel Data</span><o:p></o:p></p>
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<p class="MsoNormal"><span lang="EN-US"> </span><o:p></o:p></p>
<p><span lang="EN-US" style="font-family:"Calibri",sans-serif">Hi,</span><span lang="EN-US">
</span><o:p></o:p></p>
<p><span lang="EN-US" style="font-family:"Calibri",sans-serif">On Mon, Mar 12, 2018 at 08:59:11PM +0000, Christian Schulze wrote:</span><span lang="EN-US">
<br>
</span><span lang="EN-US" style="font-family:"Calibri",sans-serif">> I'm trying to update the QStandardItemModel data from another thread. This causes several issues:</span><span lang="EN-US">
<br>
</span><span lang="EN-US" style="font-family:"Calibri",sans-serif">></span><span lang="EN-US">
<br>
</span><span lang="EN-US" style="font-family:"Calibri",sans-serif">> [...]</span><span lang="EN-US">
</span><o:p></o:p></p>
<p><span lang="EN-US" style="font-family:"Calibri",sans-serif">QStandardItemModel is part of QtGui, and stuff in QtGui is not</span><span lang="EN-US">
<br>
</span><span lang="EN-US" style="font-family:"Calibri",sans-serif">threadsafe and must be used from the main (GUI) thread only.</span><span lang="EN-US">
</span><o:p></o:p></p>
<p><span lang="EN-US" style="font-family:"Calibri",sans-serif">> It would be great if someone could tell me how to fix this!</span><span lang="EN-US">
</span><o:p></o:p></p>
<p><span lang="EN-US" style="font-family:"Calibri",sans-serif">Your only option is pretty much "don't do this". Why do you need to</span><span lang="EN-US">
<br>
</span><span lang="EN-US" style="font-family:"Calibri",sans-serif">modify a QStandardItemModel from a non-main thread?</span><span lang="EN-US">
</span><o:p></o:p></p>
<p><span lang="EN-US" style="font-family:"Calibri",sans-serif">Florian</span><span lang="EN-US">
</span><o:p></o:p></p>
<p><span lang="EN-US" style="font-family:"Calibri",sans-serif">-- </span><span lang="EN-US"><br>
</span><span style="font-family:"Calibri",sans-serif"><a href="https://www.qutebrowser.org"><span lang="EN-US">https://www.qutebrowser.org</span></a></span><span lang="EN-US" style="font-family:"Calibri",sans-serif"> |
</span><span style="font-family:"Calibri",sans-serif"><a href="mailto:me@the-compiler.org"><span lang="EN-US">me@the-compiler.org</span></a></span><span lang="EN-US" style="font-family:"Calibri",sans-serif"> (Mail/XMPP)</span><span lang="EN-US">
<br>
</span><span lang="EN-US" style="font-family:"Calibri",sans-serif"> GPG: 916E B0C8 FD55 A072 |
</span><span style="font-family:"Calibri",sans-serif"><a href="https://the-compiler.org/pubkey.asc"><span lang="EN-US">https://the-compiler.org/pubkey.asc</span></a></span><span lang="EN-US">
<br>
</span><span lang="EN-US" style="font-family:"Calibri",sans-serif"> I love long mails!
</span><span style="font-family:"Calibri",sans-serif">| <a href="https://email.is-not-s.ms/">
https://email.is-not-s.ms/</a></span> <o:p></o:p></p>
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<p class="MsoNormal">_______________________________________________<br>
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