Running A Profiled App on X86_64 Android Emulator Qt6.9.1

[SMF-Qt]

I am trying to investigate a Qt6 performance issue with an application I am working on running on an X86_64 Android emulator .
see [https://forum.qt.io/topic/162592/android-x86_64-app-crashes-before-reaching-qt-main].
I have turned on the clang++ profiling support ( -fprofile-instr-generate and -fcoverage-mapping ) when I compile my app, but I cannot find where the output is going in the emulator.
I am not even sure if this is the correct method.
Also I don't think my application is exiting properly which may mean the profiling information is not being written out even though I am calling "exit()" at the end of my main.cxx.
Under the debugger the code usually ends of in what looks like a java abort routine and the display seems to show some sort of shell remaining:

screenshot from Samsung Tab9 runnning the same app compiled for arm64-v8a.

Any help would be good thanks.

[SMF-Qt]

@SMF-Qt

I have found that if I tap the "shell" my application restarts so even though I have called exit my app seems to have not really shutdown (a requirement for profiling).
Can anyone explain this behaviour please.

my current code to exit my app is:

...
app->setQuitOnLastWindowClosed(true);
ret=app->exec();
}
db_conn.close();
}
delete app;
exit(ret);
}

[jsulm]

@SMF-Qt said in Running A Profiled App on X86_64 Android Emulator Qt6.9.1:

I have found that if I tap the "shell"

What shell do you mean?
On Android you need to stop an application explicitly.
On a phone you tap on the bottom right button and swipe up the app you want to close.

[SMF-Qt]

@jsulm

So from what you have said my c++ exit does not close the "App" that has to be done by swiping up the what I call a shell (or is it a java wrapper)?

[SGaist]

Hi,

Are you sure you are closing your application and not just putting it in the background ? Just leaving it to return to the shell (the name is confusing as most people associate shell with a terminal running bash, zsh, etc.) does not equal stopping it.
Also

return ret;

would be the expect way to end your application.

[SMF-Qt]

Yes I was using "return ret;" How would you suggest I close my App?
Thanks

[JonB]

@SMF-Qt
But your code shows you using exit(ret);. @SGaist is suggesting you try replacing it with return ret; (assuming what you showed is in your main()) in case that makes any difference. Have you tried that?

You might put some qDebug() or whatever is appropriate immediately above that just to make sure whether your app really is exiting the exec() loop.

[SMF-Qt]

@JonB

I started with that and it is back in the current main.cpp. The behavior is the same.
The debug version on the X86_64 simulator goes throught this code so I assume the arm64-v8a version on my phones and tablet does too.

[SGaist]

As I wrote before, just returning to the shell does not mean your application is closed.
You have to explicitly close it.

[SMF-Qt]

@SGaist

Thanks but I don't know how that is done on Android.

[SGaist]

AFAIR, if you swipe from the bottom up, it should show you all the applications that are running and you can there stop them.

[SMF-Qt]

@SGaist

Yes I know that but I was looking for a programatic way.

[SGaist]

Depending on what you have in mind, a QTimer calling the application quit slot might do what you want.

[SMF-Qt]

@SGaist

Thanks but I have a quit button on my app which calls QWidget::close on the top level widget which shuts down my application apart from the database which is handled by main.
I have set app->setQuitOnLastWindowClosed(true); and app->exec() is returning 0 so everything is shutdown. once app->exec() returns the database is closed and the app destructors are run via the delete app at the very end of main. I am confident having debugged the emulated version of my app that my code is shutting everything down and exiting with a return value of 0.