Hello
I have been experimenting with my custom app that uses webkit2gtk.
For testing I use Ubuntu 14.04.1 LTS linux.
While testing I have encountered one strange thing.
Usually when WebKitWebProcess crashes or or is killed for some reason,
then "web-process-crashed" signal is emitted in UI process. WebProcess
is respawned and everything works fine after that.
But rarely when WebProcess is being re-spawned, process locks
somewhere, leaving web session unresponsive.
The only solution (without restarting the whole app) is to kill only
WebProcess, which will cause UI process to re spawn WebProcess again.
After this and reloading the page everything works fine again.
I have investigated problem further and I have discovered that locked
WebProcess is running with only one system thread.
This was unusual for WebKitWebProcess which usulay runs with several
threads.
After attaching debuger to such process I suspect for the problem to
have something to do with "dbus_launch".
Here I got one of such processes on gdb. The stack trace looks like this:
|(gdb) bt
#0 __lll_lock_wait () at
../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135
#1 0x00007fda3cfa4657 in _L_lock_909 ()
from/lib/x86_64-linux-gnu/libpthread.so.0
#2 0x00007fda3cfa4480 in __GI___pthread_mutex_lock (mutex=0x7fd9e4f7d420)
at ../nptl/pthread_mutex_lock.c:79
#3 0x00007fd9e4d54e23 in ?? () from
/usr/lib/x86_64-linux-gnu/libp11-kit.so.0
#4 0x00007fda3d279f87 in __libc_fork () at
../nptl/sysdeps/unix/sysv/linux/x86_64/../fork.c:188
#5 0x00007fda37cfe54c in fork_exec_with_pipes
(intermediate_child=intermediate_child@entry=0,
working_directory=working_directory@entry=0x0,
argv=0x7fd9d0003e60, envp=envp@entry=0x0,
close_descriptors=close_descriptors@entry=1, search_path=search_path@entry=1,
search_path_from_envp=search_path_from_envp@entry=0,
stdout_to_null=stdout_to_null@entry=0, stderr_to_null=0,
child_inherits_stdin=child_inherits_stdin@entry=0,
file_and_argv_zero=file_and_argv_zero@entry=0,
cloexec_pipes=cloexec_pipes@entry=0,
child_setup=child_setup@entry=0x0, user_data=user_data@entry=0x0,
child_pid=child_pid@entry=0x7fd9e5fbf7e8,
standard_input=standard_input@entry=0x0,
standard_output=standard_output@entry=0x7fd9e5fbf7e0,
standard_error=standard_error@entry=0x7fd9e5fbf7e4,
error=error@entry=0x7fd9e5fbf988)
at/build/buildd/glib2.0-2.40.2/./glib/gspawn.c:1326
#6 0x00007fda37cfee18 in g_spawn_sync
(working_directory=working_directory@entry=0x0, argv=<optimized out>,
envp=envp@entry=0x0,
flags=flags@entry=G_SPAWN_SEARCH_PATH, child_setup=child_setup@entry=0x0,
user_data=user_data@entry=0x0,
standard_output=standard_output@entry=0x7fd9e5fbf920,
standard_error=standard_error@entry=0x7fd9e5fbf928,
exit_status=exit_status@entry=0x7fd9e5fbf91c,
error=error@entry=0x7fd9e5fbf988)
at/build/buildd/glib2.0-2.40.2/./glib/gspawn.c:277
#7 0x00007fda37cff517 in g_spawn_command_line_sync (
command_line=command_line@entry=0x7fd9d0003d40 "dbus-launch
--autolaunch=b0e3226568f3ba144a55c2e2548aba21 --binary-syntax --close-stderr",
standard_output=standard_output@entry=0x7fd9e5fbf920,
standard_error=standard_error@entry=0x7fd9e5fbf928,
exit_status=exit_status@entry=0x7fd9e5fbf91c,
error=error@entry=0x7fd9e5fbf988)
at/build/buildd/glib2.0-2.40.2/./glib/gspawn.c:721
#8 0x00007fda3911bc00 in get_session_address_dbus_launch
(error=error@entry=0x7fd9e5fbf988)
at/build/buildd/glib2.0-2.40.2/./gio/gdbusaddress.c:1073
#9 0x00007fda3911d48a in get_session_address_platform_specific
(error=0x7fd9e5fbf988) at/build/buildd/glib2.0-2.40.2/./gio/gdbusaddress.c:1446
#10 g_dbus_address_get_for_bus_sync
(bus_type=bus_type@entry=G_BUS_TYPE_SESSION, cancellable=cancellable@entry=0x0,
error=error@entry=0x7fd9e5fbfa78)
at/build/buildd/glib2.0-2.40.2/./gio/gdbusaddress.c:1530
#11 0x00007fda391281fe in get_uninitialized_connection
(bus_type=G_BUS_TYPE_SESSION, cancellable=cancellable@entry=0x0,
error=error@entry=0x7fd9e5fbfa78)
at/build/buildd/glib2.0-2.40.2/./gio/gdbusconnection.c:6965
#12 0x00007fda3912d6bb in g_bus_get_sync (bus_type=<optimized out>,
cancellable=0x0, error=0x7fd9e5fbfa78)
at/build/buildd/glib2.0-2.40.2/./gio/gdbusconnection.c:7042
#13 0x00007fd9ec18cf90 in ?? () from
/usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#14 0x00007fd9ec18d06d in ?? () from
/usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#15 0x00007fda37cbace5 in g_main_dispatch (context=0x1cbcce0) at
/build/buildd/glib2.0-2.40.2/./glib/gmain.c:3064
#16 g_main_context_dispatch (context=context@entry=0x1cbcce0)
at/build/buildd/glib2.0-2.40.2/./glib/gmain.c:3663
#17 0x00007fda37cbb048 in g_main_context_iterate (context=context@entry=0x1cbcce0,
block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
at/build/buildd/glib2.0-2.40.2/./glib/gmain.c:3734
#18 0x00007fda37cbb0ec in g_main_context_iteration (context=0x1cbcce0,
may_block=1) at/build/buildd/glib2.0-2.40.2/./glib/gmain.c:3795
#19 0x00007fd9ec18d1ad in ?? () from
/usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#20 0x00007fda37cdff05 in g_thread_proxy (data=0x1c71cf0) at
/build/buildd/glib2.0-2.40.2/./glib/gthread.c:764
#21 0x00007fda3cfa2182 in start_thread (arg=0x7fd9e5fc0700) at
pthread_create.c:312
#22 0x00007fda3d2b330d in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:111
|
It seems everything hangs in frame 7: when spawning a dbus-launch:
|(gdb) f7
#7 0x00007fda37cff517 in g_spawn_command_line_sync (
command_line=command_line@entry=0x7fd9d0003d40 "dbus-launch
--autolaunch=b0e3226568f3ba144a55c2e2548aba21 --binary-syntax --close-stderr",
standard_output=standard_output@entry=0x7fd9e5fbf920,
standard_error=standard_error@entry=0x7fd9e5fbf928,
exit_status=exit_status@entry=0x7fd9e5fbf91c,
error=error@entry=0x7fd9e5fbf988)
at/build/buildd/glib2.0-2.40.2/./glib/gspawn.c:721
721 in /build/buildd/glib2.0-2.40.2/./glib/gspawn.c
|
And a little later in frame 5:
|#5 0x00007fda37cfe54c in fork_exec_with_pipes
(intermediate_child=intermediate_child@entry=0,
working_directory=working_directory@entry=0x0,
argv=0x7fd9d0003e60,envp=envp@entry=0x0,close_descriptors=close_descriptors@entry=1,search_path=search_path@entry=1,
search_path_from_envp=search_path_from_envp@entry=0,stdout_to_null=stdout_to_null@entry=0,stderr_to_null=0,
child_inherits_stdin=child_inherits_stdin@entry=0,file_and_argv_zero=file_and_argv_zero@entry=0,cloexec_pipes=cloexec_pipes@entry=0,
child_setup=child_setup@entry=0x0,user_data=user_data@entry=0x0,child_pid=child_pid@entry=0x7fd9e5fbf7e8,standard_input=standard_input@entry=0x0,
standard_output=standard_output@entry=0x7fd9e5fbf7e0,standard_error=standard_error@entry=0x7fd9e5fbf7e4,error=error@entry=0x7fd9e5fbf988)
at /build/buildd/glib2.0-2.40.2/./glib/gspawn.c:1326
1326 in /build/buildd/glib2.0-2.40.2/./glib/gspawn.c
(gdb) i locals
pid = -1
stdin_pipe = {-1, -1}
stdout_pipe = {18,19}
stderr_pipe = {20,21}
child_err_report_pipe = {14,17}
child_pid_report_pipe = {-1, -1}
pipe_flags = 0
status = 4
|
And frame 8:
|(gdb) f8
#8 0x00007fda3911bc00 in get_session_address_dbus_launch
(error=error@entry=0x7fd9e5fbf988)
at/build/buildd/glib2.0-2.40.2/./gio/gdbusaddress.c:1073
1073 /build/buildd/glib2.0-2.40.2/./gio/gdbusaddress.c: No such file or
directory.
(gdb) i locals
ret =0x0
machine_id =0x7fd9d0003d10 "b0e3226568f3ba144a55c2e2548aba21"
command_line =0x7fd9d0003d40 "dbus-launch
--autolaunch=b0e3226568f3ba144a55c2e2548aba21 --binary-syntax --close-stderr"
launch_stdout =0x0
launch_stderr =0x0
exit_status =32729
old_dbus_verbose =0x0
restore_dbus_verbose =0
Best
Miha
|
_______________________________________________
webkit-gtk mailing list
[email protected]
https://lists.webkit.org/mailman/listinfo/webkit-gtk
