Bug 428808

Summary: Freeze when adding sensor groups as text sensors
Product: [Applications] plasma-systemmonitor Reporter: Noah Davis <noahadvs>
Component: generalAssignee: KSysGuard Developers <ksysguard-bugs>
Status: RESOLVED FIXED    
Severity: normal CC: ahiemstra, justin.zobel, kde, kde, plasma-bugs-null
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: LLDB backtrace

Description Noah Davis 2020-11-07 22:06:42 UTC
SUMMARY
When adding a sensor group as text sensors, the UI completely freezes up.

The only sensor group I'm aware of is the CPU sensor group.

STEPS TO REPRODUCE
1. Go to the default Overview page of plasma-systemmonitor and enter edit mode
2. Click on the Networks section of the 2nd row
3. Click on the Text-Only Sensors field
4. Go to CPUs->[Group] CPU
5. Click on [Group] Total Usage (%)

OBSERVED RESULT
The UI freezes

EXPECTED RESULT
The UI should not freeze and the sensor group should be added as text-only sensors

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20201030
KDE Plasma Version: 5.20.80
KDE Frameworks Version: 5.76.0
Qt Version: 5.15.1
Kernel Version: 5.8.4-1-default
OS Type: 64-bit
Processors: 4 × Intel® Core™ i7-6500U CPU @ 2.50GHz
Memory: 7.6 GiB of RAM
Graphics Processor: Mesa DRI Intel® HD Graphics 520
Comment 1 Noah Davis 2020-11-07 22:10:51 UTC
I tried running the application in GDB. This is the relevant part of the console output, but it doesn't seem particularly helpful. None of the lines were repeated endlessly, the UI just completely froze.

Thread 18 "plasma-systemmo" received signal SIGTRAP, Trace/breakpoint trap.
[Switching to LWP 20944]
dl_open_worker (a=0x7ffffffe5220) at dl-open.c:754
754     in dl-open.c
(gdb) c
Continuing.
file:///usr/lib64/qt5/qml/org/kde/newstuff/qml/QuestionAsker.qml:91:5: QML Connections: Cannot assign to non-existent property "onClosing"
file:///usr/lib64/qt5/qml/org/kde/newstuff/qml/QuestionAsker.qml:91:5: QML Connections: Cannot assign to non-existent property "onClosing"
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/ActionToolBar.qml:110:18: QML ToolBarLayout: Binding loop detected for property "actions"
file:///usr/lib64/qt5/qml/QtQuick/Controls.2/org.kde.desktop/ScrollView.qml:89:25: QML ScrollBar: Binding loop detected for property "visible"
Qt Quick Layouts: Polish loop detected. Aborting after two iterations.
file::/Choices.qml:268:5: QML Popup: Binding loop detected for property "contentHeight"
file::/Choices.qml:268:5: QML Popup: Binding loop detected for property "contentHeight"
^C
Thread 18 "plasma-systemmo" received signal SIGINT, Interrupt.
0x00007ffff52b3082 in ?? ()
(gdb) q
Comment 2 David Edmundson 2020-11-07 23:11:52 UTC
In gdb when you get to this line:

Thread 18 "plasma-systemmo" received signal SIGINT, Interrupt.

and the prompt again type:

"thread apply all bt"

to get the backtrace
Comment 3 Justin Zobel 2020-11-07 23:42:16 UTC
.
Comment 4 Noah Davis 2020-11-08 03:27:29 UTC
Created attachment 133125 [details]
LLDB backtrace

GDB's backtrace looked completely useless even though it didn't say I was missing any debug symbols, so here's an LLDB backtrace.
Comment 5 Bug Janitor Service 2020-11-23 04:34:11 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 6 Christoph Feck 2020-12-01 12:07:43 UTC
New information was added with comment 4; changing status for inspection.
Comment 7 David Redondo 2021-02-05 09:45:17 UTC
This cannot happen anymore since we now resolve sensors async and  don't block with waitForFinished().