Crash when unmounting volume

[Rico Tzschichholz]

I got two different traces when unmounting an usb stick with Mounter docklet. This does not happen with every unmount.

1. Trace:

Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.NullReferenceException: Object reference not set to an instance of an object
  at GLib.Timeout+TimeoutProxy.Handler () [0x00000]
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at GLib.Timeout+TimeoutProxy.Handler()
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Docky.Docky.Main(System.String[] args)

2. Trace:

Stacktrace:

  at (wrapper managed-to-native) Gtk.Application.gtk_main () <0x00052>
  at (wrapper managed-to-native) Gtk.Application.gtk_main () <0xffffffff>
  at Gtk.Application.Run () <0x0000b>
  at Docky.Docky.Main (string[]) <0x00277>
  at (wrapper runtime-invoke) Docky.Docky.runtime_invoke_void_object (object,intptr,intptr,intptr) <0xffffffff>

Native stacktrace:

 mono() [0x47b77f]
 mono() [0x4aef3f]
 /lib/libpthread.so.0(+0xf8f0) [0x7febce12b8f0]
 [0x7febc58fe0e0]

Debug info from gdb:

[Thread debugging using libthread_db enabled]
[New Thread 0x7febb9dae710 (LWP 10737)]
[New Thread 0x7febb9fb3710 (LWP 10735)]
[New Thread 0x7febba2a4710 (LWP 10733)]
[New Thread 0x7febba4a9710 (LWP 10731)]
[New Thread 0x7febba6ae710 (LWP 10730)]
[New Thread 0x7febcc9c5710 (LWP 10708)]
[New Thread 0x7febcee2d710 (LWP 10707)]
0x00007febce12a93d in read () from /lib/libpthread.so.0
  8 Thread 0x7febcee2d710 (LWP 10707) 0x00007febce12b11d in nanosleep ()
   from /lib/libpthread.so.0
  7 Thread 0x7febcc9c5710 (LWP 10708) 0x00007febce129b50 in sem_wait ()
   from /lib/libpthread.so.0
  6 Thread 0x7febba6ae710 (LWP 10730) 0x00007febce127bc9 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
  5 Thread 0x7febba4a9710 (LWP 10731) 0x00007febcdbfdcd3 in epoll_wait ()
   from /lib/libc.so.6
  4 Thread 0x7febba2a4710 (LWP 10733) 0x00007febce127bc9 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
  3 Thread 0x7febb9fb3710 (LWP 10735) 0x00007febce127bc9 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
  2 Thread 0x7febb9dae710 (LWP 10737) 0x00007febce127bc9 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
* 1 Thread 0x7febcee20740 (LWP 10688) 0x00007febce12a93d in read ()
   from /lib/libpthread.so.0

Thread 8 (Thread 0x7febcee2d710 (LWP 10707)):
#0 0x00007febce12b11d in nanosleep () from /lib/libpthread.so.0
#1 0x0000000000556342 in ?? ()
#2 0x00007febce1229ca in start_thread () from /lib/libpthread.so.0
#3 0x00007febcdbfd6dd in clone () from /lib/libc.so.6
#4 0x0000000000000000 in ?? ()

Thread 7 (Thread 0x7febcc9c5710 (LWP 10708)):
#0 0x00007febce129b50 in sem_wait () from /lib/libpthread.so.0
#1 0x00000000004e4aaa in ?? ()
#2 0x0000000000505035 in ?? ()
#3 0x0000000000570073 in ?? ()
#4 0x000000000058de21 in ?? ()
#5 0x00007febce1229ca in start_thread () from /lib/libpthread.so.0
#6 0x00007febcdbfd6dd in clone () from /lib/libc.so.6
#7 0x0000000000000000 in ?? ()

Thread 6 (Thread 0x7febba6ae710 (LWP 10730)):
#0 0x00007febce127bc9 in pthread_cond_timedwait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
#1 0x000000000055b501 in ?? ()
#2 0x0000000000573f59 in ?? ()
#3 0x0000000000503e47 in ?? ()
#4 0x0000000041aecddb in ?? ()
#5 0x00000000020fed60 in ?? ()
#6 0x00007febbb5b10d0 in ?? ()
#7 0xffffffffffffffff in ?? ()
#8 0x0000000000000008 in ?? ()
#9 0x00007febc0e034a8 in ?? ()
#10 0x00007febba6ada20 in ?? ()
#11 0x00007febba6ad970 in ?? ()
#12 0x00007febbb5b10d0 in ?? ()
#13 0xffffffffffffffff in ?? ()
#14 0x0000000000000008 in ?? ()
#15 0x00007febbb9362d0 in ?? ()
#16 0x0000000041aec9f8 in ?? ()
#17 0x00000000020fed60 in ?? ()
#18 0x0000000000000000 in ?? ()

Thread 5 (Thread 0x7febba4a9710 (LWP 10731)):
#0 0x00007febcdbfdcd3 in epoll_wait () from /lib/libc.so.6
#1 0x00000000005084f7 in ?? ()
#2 0x0000000000505035 in ?? ()
#3 0x0000000000570073 in ?? ()
#4 0x000000000058de21 in ?? ()
#5 0x00007febce1229ca in start_thread () from /lib/libpthread.so.0
#6 0x00007febcdbfd6dd in clone () from /lib/libc.so.6
#7 0x0000000000000000 in ?? ()

Thread 4 (Thread 0x7febba2a4710 (LWP 10733)):
#0 0x00007febce127bc9 in pthread_cond_timedwait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
#1 0x000000000055b501 in ?? ()
#2 0x0000000000573f59 in ?? ()
#3 0x0000000000503e47 in ?? ()
#4 0x0000000041aecddb in ?? ()
#5 0x0000000002189340 in ?? ()
#6 0x0000000000584f02 in ?? ()
#7 0x00007febba2a3a20 in ?? ()
#8 0x00007febba2a3970 in ?? ()
#9 0x00007febbb599e38 in ?? ()
#10 0xffffffffffffffff in ?? ()
#11 0x0000000000000008 in ?? ()
#12 0x00007febbb58da80 in ?? ()
#13 0x0000000041aec9f8 in ?? ()
#14 0x0000000002189340 in ?? ()
#15 0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7febb9fb3710 (LWP 10735)):
#0 0x00007febce127bc9 in pthread_cond_timedwait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
#1 0x000000000055b501 in ?? ()
#2 0x0000000000573f59 in ?? ()
#3 0x0000000000503e47 in ?? ()
#4 0x0000000041aecddb in ?? ()
#5 0x0000000001dffb70 in ?? ()
#6 0x0000000000584f02 in ?? ()
#7 0x00007febb9fb2a20 in ?? ()
#8 0x00007febb9fb2970 in ?? ()
#9 0x00007febbb599820 in ?? ()
#10 0xffffffffffffffff in ?? ()
#11 0x0000000000000008 in ?? ()
#12 0x00007febbb58d630 in ?? ()
#13 0x0000000041aec9f8 in ?? ()
#14 0x0000000001dffb70 in ?? ()
#15 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7febb9dae710 (LWP 10737)):
#0 0x00007febce127bc9 in pthread_cond_timedwait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
#1 0x000000000055b501 in ?? ()
#2 0x0000000000573f59 in ?? ()
#3 0x0000000000503e47 in ?? ()
#4 0x0000000041aecddb in ?? ()
#5 0x00000000020fb3a0 in ?? ()
#6 0x0000000000584f02 in ?? ()
#7 0x00007febb9dada20 in ?? ()
#8 0x00007febb9dad970 in ?? ()
#9 0x00007febbb599208 in ?? ()
#10 0xffffffffffffffff in ?? ()
#11 0x0000000000000008 in ?? ()
#12 0x00007febc41e3c90 in ?? ()
#13 0x0000000041aec9f8 in ?? ()
#14 0x00000000020fb3a0 in ?? ()
#15 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7febcee20740 (LWP 10688)):
#0 0x00007febce12a93d in read () from /lib/libpthread.so.0
#1 0x000000000047b8f4 in ?? ()
#2 0x00000000004aef3f in ?? ()
#3 <signal handler called>
#4 0x00007febc58fe0e0 in ?? ()
#5 0x00007febbb643cde in ?? ()
   from /usr/lib/gio/modules/libgioremote-volume-monitor.so
#6 0x00007febbb640a22 in ?? ()
   from /usr/lib/gio/modules/libgioremote-volume-monitor.so
#7 0x00007febbdbacff4 in ?? () from /usr/lib/libgvfscommon.so.0
#8 0x00007febbf3b3eca in ?? () from /lib/libdbus-1.so.3
#9 0x00007febbf3b610f in dbus_connection_dispatch () from /lib/libdbus-1.so.3
#10 0x00007febbdbab895 in ?? () from /usr/lib/libgvfscommon.so.0
#11 0x00007febce7838c2 in g_main_context_dispatch ()
   from /lib/libglib-2.0.so.0
#12 0x00007febce787748 in ?? () from /lib/libglib-2.0.so.0
#13 0x00007febce787c55 in g_main_loop_run () from /lib/libglib-2.0.so.0
#14 0x00007febc7179af7 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
#15 0x000000004063fc32 in ?? ()
#16 0x0000000001d07120 in ?? ()
#17 0x0000000000000000 in ?? ()

=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================

[Chris S. (cszikszoy)]

Not really sure what could be causing these. I've used the mounter with ipods, CDs, USB Drives and internal hard drives, and haven't had a problem unmounting. Can you give a little more info on the type of drive you see this with?

[Rico Tzschichholz (ricotz)]

I noticed it with this device, but it could also be related to a lucid problem. It is hard to reproduce.

USB stick with 2GB formatted with FAT32
Bus 001 Device 012: ID 0951:1601 Kingston Technology DataTraveler II+ Pen Drive

[lusepuster (thoeger)]

This bug affects me too. Ubuntu Lucid x86_64, newest Docky from PPA.

[Robert Dyer (psybers)]

Are we certain this bug is caused by unmounting a usb stick? I have had the dock crash (with similar traces) quite a bit lately and I dont mount/unmount any device(s).

[Aiden Nibali (anibali)]

I have also noticed crashes upon unmounting devices. I'm running Ubuntu 10.04, and `docky -V` says:
[Info 18:35:41.114] Docky version: 2.0.6 bzr docky r1346 pre-release
[Info 18:35:41.127] Kernel version: 2.6.32.24
[Info 18:35:41.129] CLR version: 2.0.50727.1433

[Robert Dyer (psybers)]

@dismal_denizen: we need the stack trace when it crashes. If you have Docky starting automatically this is most likely showing up in the ~/.xsession-errors file (please trim that file to the relevant part and post it here).

[Aiden Nibali (anibali)]

~/.xsession-errors doesn't show anything helpful, but running Docky from the terminal spews out the following stack trace:

Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.NullReferenceException: Object reference not set to an instance of an object
  at GLib.Timeout+TimeoutProxy.Handler () [0x00000]
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at GLib.Timeout+TimeoutProxy.Handler()
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Docky.Docky.Main(System.String[] args)
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose

You'll notice that this is similar to the first stack trace mentioned in the original bug description.

[Waldgeist_dI (noway)]

[Info 09:33:37.075] Docky version: 2.0.5 Release
[Info 09:33:37.087] Kernel version: 2.6.32.24
[Info 09:33:37.087] CLR version: 2.0.50727.1433
Docky 0.1.0.0 - GPL

I'm also having this problem. Up until today I used the applet for the GNOME panel to open and unmount shares and USB storage devices. I decided to switch to the docky implementation of that feature and now Docky crashes randomly upon unmounting a Buffalo external harddrive (500 GB).

[Waldgeist_dI (noway)]

Trimmed contents of the .xsession-errors (I hope I copied the interesting part; it's a bit confusing):

Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.NullReferenceException: Object reference not set to an instance of an object
  at GLib.Timeout+TimeoutProxy.Handler () [0x00000]
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at GLib.Timeout+TimeoutProxy.Handler()
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Docky.Docky.Main(System.String[] args)
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose

[shrinux (shrinux)]

I encounter the same problem in two deferent PCs. A desktop and a laptop.
Both are running Ubuntu 10.04 32bit.
It mostly happens when removing volume icons from Docky to perform an unmount action.

[Abhimanyu (abhimanyu-chat)]

when i plug in or remove my external hard drive Docky automatically closes. I have to restart the app from ubuntu Dash