Also document which fields require such a check in order to have correct
threading semantics.
This usage doesn't matches the GInitable documentation, which suggests
use of a GError - but using an uninitialized GDBusConnection is
programming error, and not usefully recoverable. (The GInitable
documentation may have been a mistake - GNOME#662208.) Also, not all of
the places where we need it can raise a GError.
The check serves a dual purpose: it turns a non-deterministic crash into
a deterministic critical warning, and is also a memory barrier for
thread-safety. All of these functions dereference or return fields that
are meant to be protected by FLAG_INITIALIZED, so they could crash or
return an undefined value to their caller without this, if called from a
thread that isn't the one that called initable_init() (although I can't
think of any way to do that without encountering a memory barrier,
undefined behaviour, or a race condition that leads to undefined
behaviour if the non-initializing thread wins the race).
One exception is that initable_init() itself makes a synchronous call.
We deal with that by passing new internal flags up the call stack, to
reassure g_dbus_connection_send_message_unlocked() that it can go ahead.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661689
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661992
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
The comment implied that even failed initialization would set
is_initialized = TRUE, but this wasn't the case - failed initialization
would only set initialization_error, and it was necessary to check both.
It turns out the documented semantics are nicer than the implemented
semantics, since this lets us use atomic operations, which are also
memory barriers, to avoid needing separate memory barriers or locks
for initialization_error (and other members that are read-only after
construction).
I expect to need more than one atomically-accessed flag to fix thread
safety, so instead of a minimal implementation I've turned is_initialized
into a flags word.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661689
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661992
Reviewed-by: David Zeuthen <davidz@redhat.com>
We didn't previously test anything except the implicit default of TRUE.
Now we test implicit TRUE, explicit TRUE, explicit FALSE, and
disconnecting at the local end (which regressed while fixing Bug #651268).
Also avoid some questionable use of a main context, which fell foul of
Bug #658999 and caused this test to be disabled in master.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=662100
Bug-NB: NB#287088
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
This was a regression caused by my previous work on GDBusWorker thread-safety
(Bug #651268). The symptom is that if you disconnect a GDBusConnection
locally, the default implementation of GDBusConnection::closed
terminates your process, even though it shouldn't do that for
locally-closed connections; this is because GDBusWorker didn't think a
cancelled read was a local close.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=662100
Bug-NB: NB#287088
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: David Zeuthen <davidz@redhat.com>
GDBusConnection sets the closed flag in the worker thread, then adds an
idle callback (which refs the Connection) to signal this in the main
thread. The tests session_bus_down doesn't spin the mainloop, so the
"closed" signal will always fire if iterating the mainloop later (and
drops the ref when doing so). But _is_closed can return TRUE even before
signalling this, in which case the "closed" signal isn't fired and the
ref isn't dropped, causing the test to fail.
Instead simply always wait for the closed signal, which is a good thing
to check anyway and ensures the ref is closed.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=661896
Reviewed-by: Matthias Clasen <mclasen@redhat.com>
This was used as an optimisation for the macro hackery that used to live
in gthread.h. If a particular library or program knew that it could
rely on thread support being enabled, it would allow for static
evaluation of conditionals in some of those macros.
Since the macros are dead and thread support is now always-on, we can
get rid of this bit of legacy.
Add functions for manipulating the environment under which a
GAppLaunchContext will launch its children, to avoid thread-related
bugs with using setenv() directly.
FIXME: win32 side isn't implemented yet
https://bugzilla.gnome.org/show_bug.cgi?id=659326
With search gaining traction as being the preferred way to locate
applications, the existing .desktop file fields meant for browsing
often produce insufficient results.
gnome-control-center introduced a custom X-GNOME-Keywords field for
that purpose, which we plan to support in gnome-shell as well.
https://bugzilla.gnome.org/show_bug.cgi?id=661763
And remove the 'joinable' argument from g_thread_new() and
g_thread_new_full().
Change the wording in the docs. Clarify expectations for
(deprecated) g_thread_create().
It is possible for _g_io_module_get_default() to be called recursively
(eg, if a module of one type is loaded that tries to look up gsettings
from its init() method and ends up causing the gsettings module to be
loaded). So use a recursive mutex.
If the connection to the bus is lost while a method call is ongoing,
the method call does not get cancelled. Instead it just sits around
until it times out.
This is visible here on XO laptops when stopping the display manager
during shutdown. imsettings starts sending a sync message to give up
its bus name (via g_bus_unown_name()), then systemd terminates the
session bus at approximately the same time. imsettings then hangs for
about 20 seconds before timing out the message.
http://lists.freedesktop.org/archives/dbus/2011-September/014717.html
imsettings behaviour could be improved as described in that thread,
but I think this is a glib bug. I've also come up with the attached
patch which fixes it.
Credits for the bug-fix goes to Daniel Drake <dsd@laptop.org>. The test
case was written by David Zeuthen <zeuthen@gmail.com>.
https://bugzilla.gnome.org/show_bug.cgi?id=660637
Signed-off-by: David Zeuthen <davidz@redhat.com>
Add g_main_context_ref_thread_default(), which always returns a
reffed GMainContext, rather than sometimes returning a (non-reffed)
GMainContext, and sometimes returning NULL. This simplifies the
bookkeeping in any code that needs to keep a reference to the
thread-default context for a while.
https://bugzilla.gnome.org/show_bug.cgi?id=660994
Since it is valid for a D-Bus interface / service to add new methods,
signals or properties we must NEVER warn about unknown properties or
drop unknown signals or disallow unknown method invocations when we
have an expected interface.
So this means that the expected_interface machinery is only useful for
checking that the service didn't break ABI.
Also update the docs so it is clear exactly what it means to have an
expected interface.
https://bugzilla.gnome.org/show_bug.cgi?id=660886
Signed-off-by: David Zeuthen <davidz@redhat.com>
These were the last users of the dynamic allocation API.
Keep the uses in glib/tests/mutex.c since this is actually meant to test
the API (which has to continue working, even if it is deprecated).
https://bugzilla.gnome.org/show_bug.cgi?id=660739
Add _g_io_module_get_default(), which implements the
figure-out-the-best-available-module-that-is-actually-usable logic,
and use that to simplify g_proxy_resolver_get_default(),
g_settings_backend_get_default(), g_tls_backend_get_default(), and
g_vfs_get_default().
https://bugzilla.gnome.org/show_bug.cgi?id=620932
g_file_make_directory_with_parents() will fail for already
existing directories, unlike g_mkdir_with_parents(), so mention
this clearly in the docs.
https://bugzilla.gnome.org/show_bug.cgi?id=660791
The GIOScheduler was using a GCond in a way that didn't deal with the
possibility of spurious wakeups. Add an explicit predicate and a loop.
Problem caught by Matthias Clasen.
https://bugzilla.gnome.org/show_bug.cgi?id=660739
