How to diagnose GTK application freezes under Flatpak?

Platform
, ,
1

I develop a GTK application. On the host it runs fine, but on Flatpak it sometimes has short ~0.3 s freezes of the UI that I’d like to diagnose. I’ve tried recording it with sysprof (both within Builder and with sysprof-cli --gtk --use-trace-fd -- flatpak run --devel my.application.Here), but org.gnome.Sdk seems to be missing counters so I can’t tell when the freezes actually occur in the recording, and I don’t see anything odd in the backtraces as is. How can I diagnose issues like this?

I’m using org.gnome.Sdk//3.38 and can build the application inside and outside of Builder. I’m on Fedora 33, Wayland.

2

If you are asking how to debug issues within flatpak environment, you can do the following.

Below is what I use for debugging rhythmbox within flatpak

$ flatpak run --command=sh --branch=master --devel org.gnome.Rhythmbox3

[📦 org.gnome.Rhythmbox3 ~]$ 

[📦 org.gnome.Rhythmbox3 ~]$ gdb
GNU gdb (GDB) 9.2
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

(gdb)

Thanks!

3

I am familiar with using gdb inside Flatpak. I’m specifically asking how to diagnose short GTK freezes; short enough that I can’t just switch to the terminal and Ctrl-C gdb at the right moment to see the backtrace.

4

You can use Sysprof to identify main loop stalls.

5

We plan on eventually enabling sysproof builds in the Runtime itself.

1 Like
6

This seems like it will help; it’s giving me a lot of trouble trying to use it for a Flatpak application though. It needs to LD_PRELOAD its libsysprof-speedtrack-4.so (which isn’t present under Flatpak). I added sysprof to my Flatpak manifest so now I have the library in my /app/lib but it still doesn’t seem to work correctly.

7

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.