xcb_wait_for_reply deadlock

[Ville Ranki]

I have a Qt application which hangs in startup. Stack trace:

(gdb) bt
#0 0xb77b5424 in __kernel_vsyscall ()
#1 0xb3d2084b in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i386-linux-gnu/libpthread.so.0
#2 0xb2a1337b in ?? () from /usr/lib/i386-linux-gnu/libxcb.so.1
#3 0xb2a14b40 in ?? () from /usr/lib/i386-linux-gnu/libxcb.so.1
#4 0xb2a14e07 in xcb_wait_for_reply () from /usr/lib/i386-linux-gnu/libxcb.so.1
#5 0xb2a3bd0b in xcb_glx_query_version_reply () from /usr/lib/i386-linux-gnu/libxcb-glx.so.0
#6 0xa08a5740 in ?? () from /usr/lib/i386-linux-gnu/qt5/plugins/platforms/libqxcb.so
#7 0xa08a8b9a in ?? () from /usr/lib/i386-linux-gnu/qt5/plugins/platforms/libqxcb.so
#8 0xa08aa2f9 in ?? () from /usr/lib/i386-linux-gnu/qt5/plugins/platforms/libqxcb.so
#9 0xa08bb1f9 in ?? () from /usr/lib/i386-linux-gnu/qt5/plugins/platforms/libqxcb.so
#10 0xb41f57f9 in ?? () from /usr/lib/i386-linux-gnu/libQt5Gui.so.5
#11 0xb41fccf4 in QGuiApplicationPrivate::createPlatformIntegration() () from /usr/lib/i386-linux-gnu/libQt5Gui.so.5
#12 0xb41fd704 in QGuiApplicationPrivate::createEventDispatcher() () from /usr/lib/i386-linux-gnu/libQt5Gui.so.5
#13 0xb482bd4b in QApplicationPrivate::createEventDispatcher() () from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#14 0xb3f46972 in QCoreApplication::init() () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#15 0xb3f469f9 in QCoreApplication::QCoreApplication(QCoreApplicationPrivate&) () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#16 0xb41fe12a in QGuiApplication::QGuiApplication(QGuiApplicationPrivate&) () from /usr/lib/i386-linux-gnu/libQt5Gui.so.5
#17 0xb47d8de8 in QApplication::QApplication(int&, char**, int) () from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5

Google shows other reports about xcb_wait_for_reply deadlocking. This happens when starting the application
from .xsession file using nodm display manager. Starting the app from an x terminal works so i believe this is some kind of timing issue / race condition. The app in question is properietary so i cannot supply it to reproduce the issue, sorry.

Ubuntu version is Ubuntu 13.04 x86_32 with updates installed.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: libxcb1 1.8.1-2ubuntu2.1
ProcVersionSignature: Ubuntu 3.8.0-28.41-generic 3.8.13.5
Uname: Linux 3.8.0-28-generic i686
NonfreeKernelModules: nvidia
.proc.driver.nvidia.gpus.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86 Kernel Module 304.88 Wed Mar 27 14:31:12 PDT 2013
 GCC version: gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1)
.tmp.unity.support.test.0:

ApportVersion: 2.9.2-0ubuntu8.3
Architecture: i386
CheckboxSubmission: 5411b7083f2413511daec522a712c016
CheckboxSystem: b845c366ea09c60efa3a45c1b5b21525
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,workarounds,scale,expo,ezoom]
CompositorRunning: None
Date: Mon Aug 12 14:09:50 2013
DistUpgraded: 2013-05-22 13:40:23,672 DEBUG enabling apt cron job
DistroCodename: raring
DistroVariant: ubuntu
EcryptfsInUse: Yes
GraphicsCard:
 NVIDIA Corporation GT216M [NVS 5100M] [10de:0a2c] (rev a2) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Device [103c:1521]
InstallationDate: Installed on 2011-06-14 (790 days ago)
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
JockeyStatus:
 kmod:nvidia_310_updates - NVIDIA binary Xorg driver, kernel module and VDPAU library (Proprietary, Disabled, Not in use)
 kmod:nvidia_313_updates - NVIDIA binary Xorg driver, kernel module and VDPAU library (Proprietary, Disabled, Not in use)
 kmod:nvidia_304 - nvidia_304 (Proprietary, Enabled, Not in use)
 kmod:nvidia_304_updates - NVIDIA binary Xorg driver, kernel module and VDPAU library (Proprietary, Disabled, Not in use)
 kmod:nvidia_310 - NVIDIA binary Xorg driver, kernel module and VDPAU library (Proprietary, Disabled, Not in use)
MachineType: Hewlett-Packard HP EliteBook 8540p
MarkForUpload: True
PccardctlStatus:
 Socket 0:
   3.3V
  16-bit
  PC Card
   Subdevice 0 (function 0) bound to driver "pata_pcmcia"
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-28-generic root=UUID=debfbf8b-faee-4fef-887f-aaa61947d6d2 ro crashkernel=384M-2G:64M,2G-:128M quiet splash
SourcePackage: libxcb
UpgradeStatus: Upgraded to raring on 2013-05-22 (82 days ago)
XorgConf:
 Section "Device"
  Identifier "Default Device"
  Option "NoLogo" "True"
 EndSection
dmi.bios.date: 03/09/2011
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 68CVD Ver. F.0F
dmi.board.name: 1521
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 32.33
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvr68CVDVer.F.0F:bd03/09/2011:svnHewlett-Packard:pnHPEliteBook8540p:pvr:rvnHewlett-Packard:rn1521:rvrKBCVersion32.33:cvnHewlett-Packard:ct10:cvr:
dmi.product.name: HP EliteBook 8540p
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.9~daily13.06.19~13.04-0ubuntu1
version.libdrm2: libdrm2 2.4.43-0ubuntu1.1
version.libgl1-mesa-dri: libgl1-mesa-dri 9.1.4-0ubuntu0.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.1.4-0ubuntu0.1
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.13.3-0ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu2b2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.1.0-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.21.6-0ubuntu4.1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.7-0ubuntu1
xserver.bootTime: Mon Aug 12 10:00:08 2013
xserver.configfile: /etc/X11/xorg.conf
xserver.errors:
 open /dev/dri/card0: No such file or directory
 open /dev/fb0: No such file or directory
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.13.3-0ubuntu6

[Ville Ranki (ville-ranki)]

During startup i use unclutter command to hide mouse pointer. It seems that the unclutter also fails and gets stuck in same situation:

(gdb) bt
#0 0xb7755424 in __kernel_vsyscall ()
#1 0xb7538da3 in poll () from /lib/i386-linux-gnu/libc.so.6
#2 0xb743c200 in ?? () from /usr/lib/i386-linux-gnu/libxcb.so.1
#3 0xb743db40 in ?? () from /usr/lib/i386-linux-gnu/libxcb.so.1
#4 0xb743de07 in xcb_wait_for_reply () from /usr/lib/i386-linux-gnu/libxcb.so.1
#5 0xb7644692 in _XReply () from /usr/lib/i386-linux-gnu/libX11.so.6
#6 0xb7639be3 in XQueryPointer () from /usr/lib/i386-linux-gnu/libX11.so.6
#7 0x08048fdd in ?? ()
#8 0xb7470935 in __libc_start_main () from /lib/i386-linux-gnu/libc.so.6
#9 0x080499b9 in ?? ()

[Daniel Hahler (blueyed)]

Thanks for your bug report.

Is this still an issue?
Have you tried it in a later Ubuntu release / with a more recent version of libxcb (the report was against 1.8.1-2ubuntu2.1)?

[Ville Ranki (ville-ranki)]

This bug is 1.5 years old. I don't even remember what i was doing back then. I suppose it can be closed if no-one still suffers from it.

[Launchpad Janitor (janitor)]

[Expired for libxcb (Ubuntu) because there has been no activity for 60 days.]