Bug 423448

Summary: Freeze when sharing screen in browser
Product: [Plasma] plasmashell Reporter: shfbsdbvf
Component: generic-performanceAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED WORKSFORME    
Severity: normal CC: kde, nate, plasma-bugs-null
Priority: NOR    
Version First Reported In: 5.18.5   
Target Milestone: 1.0   
Platform: Kubuntu   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description shfbsdbvf 2020-06-24 14:43:44 UTC
SUMMARY
Desktop freezes completely when I try to share screen in firefox. Can be fixed with executing "plasmashell --replace" from tty. It doesn't happen every time.

STEPS TO REPRODUCE
1. Launch firefox (regular window, somehow I didn't manage to do it in private window but possibly can also happen there).
2. Go to https://screenapp.io/#/ .
3. Click "Get started", then "Share your screen", select "Entire screen" in firefox popup and click "Allow".
4. If freeze didn't happen, repeat steps 2 and 3 till it happens.

OBSERVED RESULT
Screen freezes, hotkeys don't work.

EXPECTED RESULT
Nothing bad should happen.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: kubuntu 20.04
(available in About System)
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8
Comment 1 shfbsdbvf 2020-06-24 14:45:09 UTC
Forgot to mention that during freeze plasmashell uses 100% cpu.
Comment 2 David Edmundson 2020-06-24 15:06:08 UTC
When you say the desktop freezes, does the cursor move? can you move windows about?
Comment 3 shfbsdbvf 2020-06-24 15:26:59 UTC
I can move cursor but can't move windows. Switching to console with alt+tab or with clicking on task manager entry doesn't do anything. Same with starting console with hotkey, but after "plasmashell --replace" all those console windows are on desktop.
Comment 4 David Edmundson 2020-06-26 13:38:37 UTC
That's very confusing. Half the symptoms are that kwin is frozen, yet you say restarting plasma fixes it.


Can you run "sudo gdb --pid `pidof plasmashell`" when it's frozen

when it connects then type "bt" and paste the results
Comment 5 shfbsdbvf 2020-07-01 09:48:30 UTC
Attaching to process 1159
[New LWP 1165]
[New LWP 1172]
[New LWP 1345]
[New LWP 1372]
[New LWP 1381]
[New LWP 1537]
[New LWP 1544]
[New LWP 29275]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7fbfdc00a5c0) at ../sysdeps/nptl/futex-internal.h:183
183     ../sysdeps/nptl/futex-internal.h: No such file or directory.
(gdb) bt
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7fbfdc00a5c0) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x7fbfdc00a570, cond=0x7fbfdc00a598) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x7fbfdc00a598, mutex=0x7fbfdc00a570) at pthread_cond_wait.c:638
#3  0x00007fbfe8873b0f in QWaitCondition::wait(QMutex*, QDeadlineTimer) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fbfe8873c01 in QWaitCondition::wait(QMutex*, unsigned long) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fbfea5506d2 in ?? () from /lib/x86_64-linux-gnu/libQt5Quick.so.5
#6  0x00007fbfea5515b2 in ?? () from /lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007fbfea551d6b in ?? () from /lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007fbfe8e299ad in QWindow::event(QEvent*) () from /lib/x86_64-linux-gnu/libQt5Gui.so.5
#9  0x00007fbfea5b5159 in QQuickWindow::event(QEvent*) () from /lib/x86_64-linux-gnu/libQt5Quick.so.5
#10 0x000055bcc48cf90f in ?? ()
#11 0x00007fbfe94a9a66 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib/x86_64-linux-gnu/libQt5Widgets.so.5
#12 0x00007fbfe94b30f0 in QApplication::notify(QObject*, QEvent*) () from /lib/x86_64-linux-gnu/libQt5Widgets.so.5
#13 0x00007fbfe8a3593a in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#14 0x00007fbfe8e1fde6 in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) () from /lib/x86_64-linux-gnu/libQt5Gui.so.5
#15 0x00007fbfe8e20014 in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) () from /lib/x86_64-linux-gnu/libQt5Gui.so.5
#16 0x00007fbfe8dfa35b in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Gui.so.5
#17 0x00007fbfe44b232e in ?? () from /lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#18 0x00007fbfe7115fbd in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007fbfe7116240 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007fbfe71162e3 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007fbfe8a8d565 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#22 0x00007fbfe8a344db in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007fbfe8a3c246 in QCoreApplication::exec() () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#24 0x000055bcc48b5b25 in ?? ()
#25 0x00007fbfe84010b3 in __libc_start_main (main=0x55bcc48b4ea0, argc=1, argv=0x7fff435597c8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff435597b8) at ../csu/libc-start.c:308
#26 0x000055bcc48b5cde in _start ()
Comment 6 David Edmundson 2020-07-01 10:55:40 UTC
That shows it as not being frozen.
Comment 7 David Edmundson 2020-07-01 10:57:56 UTC
Edit, ignore my last comment.

We're at a mutex in QtQuick presumably waiting for the render thread.
Comment 8 Nate Graham 2023-09-19 20:21:31 UTC
Hello and thank you again for the bug report! Unfortunately we were not able to address it yet, nor even manage to reproduce the issue ourselves. Can we ask you to please check if this issue is still happening with Plasma 5.27?

If it is, please change the status to REPORTED. Thanks a lot!
Comment 9 Bug Janitor Service 2023-10-04 03:46:42 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 10 Bug Janitor Service 2023-10-19 03:46:05 UTC
This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now 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

Thank you for helping us make KDE software even better for everyone!
Comment 11 shfbsdbvf 2023-11-26 13:00:06 UTC
Sorry for late response, I indeed didn't experience this bug since 2020.