[kwin] [Bug 400854] New: kwin crash when restarting IntelliJ application

[Marcus Better]

https://bugs.kde.org/show_bug.cgi?id=400854

Bug ID: 400854
Summary: kwin crash when restarting IntelliJ application
Product: kwin
Version: 5.13.5
Platform: Debian testing
OS: Linux
Status: REPORTED
Keywords: drkonqi
Severity: crash
Priority: NOR
Component: general
Assignee: kwin-bugs-***@kde.org
Reporter: ***@better.se
Target Milestone: ---

Application: kwin_x11 (5.13.5)

Qt Version: 5.11.2
Frameworks Version: 5.49.0
Operating System: Linux 4.19.1-better x86_64
Distribution: Debian GNU/Linux testing (buster)

-- Information about the crash:
- What I was doing when the application crashed:

Was restarting the IntelliJ IDEA application (the feature that restarts the IDE
after a plugin update).

-- Backtrace:
Application: Kwin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f1e200bb940 (LWP 2574))]

Thread 5 (Thread 0x7f1e1d1b1700 (LWP 4321)):
#0 0x00007f1e28ad6e6c in futex_wait_cancelable (private=<optimized out>,
expected=0, futex_word=0x55e668c385a0) at
../sysdeps/unix/sysv/linux/futex-internal.h:88
#1 __pthread_cond_wait_common (abstime=0x0, mutex=0x55e668c38550,
cond=0x55e668c38578) at pthread_cond_wait.c:502
#2 __pthread_cond_wait (cond=0x55e668c38578, mutex=0x55e668c38550) at
pthread_cond_wait.c:655
#3 0x00007f1d87950e2b in cnd_wait (mtx=0x55e668c38550, cond=0x55e668c38578) at
../../../include/c11/threads_posix.h:155
#4 util_queue_thread_func (input=***@entry=0x55e668d596e0) at
../../../src/util/u_queue.c:255
#5 0x00007f1d87950b57 in impl_thrd_routine (p=<optimized out>) at
../../../include/c11/threads_posix.h:87
#6 0x00007f1e28ad0f2a in start_thread (arg=0x7f1e1d1b1700) at
pthread_create.c:463
#7 0x00007f1e2b2b9edf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7f1e0f3fe700 (LWP 2702)):
#0 0x00007f1e28ad6e6c in futex_wait_cancelable (private=<optimized out>,
expected=0, futex_word=0x7f1e298c4fb8 <QTWTF::pageheap_memory+57592>) at
../sysdeps/unix/sysv/linux/futex-internal.h:88
#1 __pthread_cond_wait_common (abstime=0x0, mutex=0x7f1e298c4f68
<QTWTF::pageheap_memory+57512>, cond=0x7f1e298c4f90
<QTWTF::pageheap_memory+57552>) at pthread_cond_wait.c:502
#2 __pthread_cond_wait (cond=0x7f1e298c4f90 <QTWTF::pageheap_memory+57552>,
mutex=0x7f1e298c4f68 <QTWTF::pageheap_memory+57512>) at pthread_cond_wait.c:655
#3 0x00007f1e297cde2a in QTWTF::TCMalloc_PageHeap::scavengerThread
(this=0x7f1e298b6ec0 <QTWTF::pageheap_memory>) at
../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#4 0x00007f1e297cde49 in QTWTF::TCMalloc_PageHeap::runScavengerThread
(context=<optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#5 0x00007f1e28ad0f2a in start_thread (arg=0x7f1e0f3fe700) at
pthread_create.c:463
#6 0x00007f1e2b2b9edf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7f1e0ffff700 (LWP 2699)):
#0 0x00007f1e2b2af836 in __GI_ppoll (fds=***@entry=0x7f1e08000d28,
nfds=***@entry=1, timeout=<optimized out>, ***@entry=0x0,
sigmask=***@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1 0x00007f1e29ea1d11 in ppoll (__ss=<optimized out>, __timeout=<optimized
out>, __nfds=<optimized out>, __fds=<optimized out>) at
/usr/include/x86_64-linux-gnu/bits/poll2.h:77
#2 qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7f1e08000d28) at
kernel/qcore_unix.cpp:132
#3 qt_safe_poll (fds=0x7f1e08000d28, nfds=***@entry=1,
timeout_ts=***@entry=0x0) at kernel/qcore_unix.cpp:153
#4 0x00007f1e29ea3189 in
QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
at ../../include/QtCore/../../src/corelib/tools/qarraydata.h:209
#5 0x00007f1e29e52d0b in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at
../../include/QtCore/../../src/corelib/global/qflags.h:140
#6 0x00007f1e29ca20c6 in QThread::exec() () at
../../include/QtCore/../../src/corelib/global/qflags.h:120
#7 0x00007f1e28300355 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8 0x00007f1e29cabc97 in QThreadPrivate::start(void*) () at
thread/qthread_unix.cpp:367
#9 0x00007f1e28ad0f2a in start_thread (arg=0x7f1e0ffff700) at
pthread_create.c:463
#10 0x00007f1e2b2b9edf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f1e1e66e700 (LWP 2608)):
#0 0x00007f1e29c9ee7f in QMutex::unlock (this=***@entry=0x55e6689056b0) at
/usr/include/c++/8/bits/atomic_base.h:742
#1 0x00007f1e29ea301c in QMutexLocker::unlock (this=<synthetic pointer>) at
../../include/QtCore/../../src/corelib/thread/qmutex.h:240
#2 QMutexLocker::~QMutexLocker (this=<synthetic pointer>, __in_chrg=<optimized
out>) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:213
#3 QThreadData::canWaitLocked (this=0x55e668905680) at
../../include/QtCore/5.11.2/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:254
#4 QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
() at kernel/qeventdispatcher_unix.cpp:472
#5 0x00007f1e29e52d0b in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at
../../include/QtCore/../../src/corelib/global/qflags.h:140
#6 0x00007f1e29ca20c6 in QThread::exec() () at
../../include/QtCore/../../src/corelib/global/qflags.h:120
#7 0x00007f1e27ddd545 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#8 0x00007f1e29cabc97 in QThreadPrivate::start(void*) () at
thread/qthread_unix.cpp:367
#9 0x00007f1e28ad0f2a in start_thread (arg=0x7f1e1e66e700) at
pthread_create.c:463
#10 0x00007f1e2b2b9edf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f1e200bb940 (LWP 2574)):
[KCrash Handler]
#6 0x0000000000000000 in ?? ()
#7 0x00007f1e2afce9ad in KWin::Workspace::constrainedStackingOrder
(this=***@entry=0x55e6689bddc0) at ./layers.cpp:504
#8 0x00007f1e2afcf1f8 in KWin::Workspace::updateStackingOrder
(this=0x55e6689bddc0, propagate_new_clients=<optimized out>) at
./layers.cpp:120
#9 0x00007f1e2afcf5c0 in KWin::Workspace::blockStackingUpdates
(this=***@entry=0x55e6689bddc0, block=***@entry=false) at ./layers.cpp:597
#10 0x00007f1e2af7fdd8 in KWin::StackingUpdatesBlocker::~StackingUpdatesBlocker
(this=<synthetic pointer>, __in_chrg=<optimized out>) at ./workspace.h:646
#11 KWin::Client::destroyClient (this=***@entry=0x55e6693ffb80) at
./client.cpp:285
#12 0x00007f1e2afda751 in KWin::Client::unmapNotifyEvent (this=0x55e6693ffb80,
e=<optimized out>) at ./events.cpp:639
#13 0x00007f1e2afdde7b in KWin::Client::windowEvent (this=0x55e6693ffb80,
e=***@entry=0x7f1e18005180) at ./events.cpp:481
#14 0x00007f1e2afdec2a in KWin::Workspace::workspaceEvent(xcb_generic_event_t*)
() at ./events.cpp:261
#15 0x00007f1e29e51b8f in
QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) ()
at kernel/qabstracteventdispatcher.cpp:466
#16 0x00007f1e1fc3ecb0 in QXcbConnection::handleXcbEvent
(this=***@entry=0x55e6688a8360, event=***@entry=0x7f1e18005180) at
qxcbnativeinterface.h:101
#17 0x00007f1e1fc3f843 in QXcbConnection::processXcbEvents() () at
qxcbconnection.cpp:1790
#18 0x00007f1e29e7db42 in QObject::event(QEvent*) () at kernel/qobject.cpp:1251
#19 0x00007f1e2a7cc491 in QApplicationPrivate::notify_helper
(this=***@entry=0x55e668871680, receiver=***@entry=0x55e6688a8360,
e=***@entry=0x7f1e1801aeb0) at kernel/qapplication.cpp:3727
#20 0x00007f1e2a7d3ad0 in QApplication::notify(QObject*, QEvent*) () at
kernel/qapplication.cpp:3486
#21 0x00007f1e29e54039 in QCoreApplication::notifyInternal2(QObject*, QEvent*)
() at
../../include/QtCore/5.11.2/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:307
#22 0x00007f1e29e5702b in QCoreApplication::sendEvent (event=0x7f1e1801aeb0,
receiver=<optimized out>) at
../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:234
#23 QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) ()
at kernel/qcoreapplication.cpp:1745
#24 0x00007f1e29ea2ffb in
QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
at kernel/qeventdispatcher_unix.cpp:466
#25 0x00007f1e1fcd0aed in QUnixEventDispatcherQPA::processEvents
(this=<optimized out>, flags=...) at qunixeventdispatcher.cpp:68
#26 0x00007f1e29e52d0b in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at
../../include/QtCore/../../src/corelib/global/qflags.h:140
#27 0x00007f1e29e5ae82 in QCoreApplication::exec() () at
../../include/QtCore/../../src/corelib/global/qflags.h:120
#28 0x00007f1e2b38947b in kdemain (argc=<optimized out>, argv=0x7ffecf338cf8)
at ./main_x11.cpp:468
#29 0x00007f1e2b1e4b17 in __libc_start_main (main=0x55e6681fe050 <main>,
argc=3, argv=0x7ffecf338cf8, init=<optimized out>, fini=<optimized out>,
rtld_fini=<optimized out>, stack_end=0x7ffecf338ce8) at ../csu/libc-start.c:310
#30 0x000055e6681fe08a in _start ()

The reporter indicates this bug may be a duplicate of or related to bug 397514,
bug 396975, bug 394701, bug 392412, bug 391395, bug 389201.

Possible duplicates by query: bug 397514, bug 396975, bug 394701, bug 392412,
bug 391395.

Reported using DrKonqi

[Vlad Zagorodniy]

https://bugs.kde.org/show_bug.cgi?id=400854

--- Comment #1 from Vlad Zagorodniy <***@gmail.com> ---
It looks like we're re-inserting deleted Client's.

For example, if we have the following unconstrained stacking order

unconstrained_stacking_order:
{ 0x5632110c9870, 0x5632110aac50, 0x5632110ddf50, 0x5632111b3100 }

and releaseWindow is called on Client 0x5632111b3100 (the last one), then
Workspace::addDeleted will replace that client with a corresponding Deleted
instance 0x563211181860

unconstrained_stacking_order (after addDeleted was called):
{ 0x5632110c9870, 0x5632110aac50, 0x5632110ddf50, 0x563211181860 }

but when Workspace::constrainedStackingOrder is called, we have the following
unconstrained stacking order

unconstrained_stacking_order:
{ 0x5632110c9870, 0x5632110aac50, 0x5632110ddf50, 0x563211181860,
0x5632111b3100 }

[Vlad Zagorodniy]

https://bugs.kde.org/show_bug.cgi?id=400854

--- Comment #2 from Vlad Zagorodniy <***@gmail.com> ---
It looks like in my case, raiseClient is called, which in its turn, adds the
deleted Client back to unconstrained stacking order.

[Vlad Zagorodniy]

https://bugs.kde.org/show_bug.cgi?id=400854

--- Comment #3 from Vlad Zagorodniy <***@gmail.com> ---
In case of bug 392412, it looks like sendClientToDesktop indirectly triggers
raiseClient.

---

@Marcus Do you use some fancy scripts to open/maximize windows on new virtual
desktops?

[Vlad Zagorodniy]

https://bugs.kde.org/show_bug.cgi?id=400854

Vlad Zagorodniy <***@gmail.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Status|REPORTED |CONFIRMED

[Marcus Better]

https://bugs.kde.org/show_bug.cgi?id=400854

--- Comment #4 from Marcus Better <***@better.se> ---
No, I have a plain Debian install. No fancy scripts that I know of.

[Vlad Zagorodniy]

https://bugs.kde.org/show_bug.cgi?id=400854

--- Comment #5 from Vlad Zagorodniy <***@gmail.com> ---
Git commit 8af6d4f5dc74385a9d52820562162dc190f452ff by Vlad Zagorodniy.
Committed on 26/11/2018 at 08:50.
Pushed by vladz into branch 'master'.

[x11] Emit clientRemoved after client was removed

Summary:
Currently, there is a guarantee that a client, which is about to be removed,
is no longer in the stacking order(both in constrained and unconstrained)
when Workspace::removeClient is called. However, because the client gets
removed from m_allClients after clientRemoved is emitted, it can be
re-inserted back into the stacking order.

In general, the pattern is to do some work and then notify others about
what you've done by emitting a signal. In the case of Workspace::removeClient,
we emit clientRemoved way before the client actually gets removed.
Related: bug 392412

Test Plan:
* Enable the following script:

```lang=js
workspace.clientAdded.connect(function (client) {
if (client.skipTaskbar || client.modal || client.transient) {
return;
}
workspace.desktops = workspace.desktops + 1;
workspace.currentDesktop = workspace.desktops;
client.desktop = workspace.currentDesktop;
});

workspace.clientRemoved.connect(function (client) {
if (client.skipTaskbar || client.modal || client.transient) {
return;
}
workspace.desktops = workspace.desktops - 1;
});
```

* Open an app, close the app.

Reviewers: #kwin, graesslin

Reviewed By: #kwin, graesslin

Subscribers: graesslin, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D17069

M +2 -2 workspace.cpp

https://commits.kde.org/kwin/8af6d4f5dc74385a9d52820562162dc190f452ff

[Vlad Zagorodniy]

https://bugs.kde.org/show_bug.cgi?id=400854

--- Comment #6 from Vlad Zagorodniy <***@gmail.com> ---
@Marcus Does this happen only when restarting IntelliJ IDEA?

[Marcus Better]

https://bugs.kde.org/show_bug.cgi?id=400854

--- Comment #7 from Marcus Better <***@better.se> ---
I cannot reproduce it consistently, so not sure in which scenarios it happens.