In the event that a GSettings object is being destroyed just as a change
signal is being delivered, the destroying thread will race with the
dconf worker thread for acquiring the lock on the GSettingsBackend.
If the signalling thread gets there first then the destroying thread
will block on the lock. The signalling thread adds a reference to the
GSettings object that is being destroyed and releases the lock. The
idea is that this should prevent the GSettings object from being
destroyed and thus maintain its entry in the list. Unfortunately, the
weak reference notify function is already running and as soon as we
release the lock, the list entry is removed.
The signalling thread crashes.
This bug is indicative of a serious problem encountered in many
situations where GObject instances are touched from multiple threads.
Ideally, we will move to a place where g_object_ref() is not called at
all on the GSettings object from the dconf worker thread and instead, a
dispatch will be done without holding a reference (similar to how
GAppInfoMonitor presently works). This would also prevent the
unfortunate case of someone dropping what they assume to be the last
reference on a GSettings object, only to have an already-pending signal
delivered once they return to the mainloop, crashing their program.
Making this change for GSettings (with multiple instances per thread,
the possibility of multiple backends and each instance being interested
in different events) is going to be extremely non-trivial, so it's not a
change that makes sense at this point in the cycle.
For now, we can do a relatively small and isolated tweak so that we
never access the list except under a lock. We still perform the bad
pattern of acquiring a ref in a foreign thread which means that we still
risk delivering a signal to a GSettings object that the user has assumed
is dead (unless they explicitly disconnect their signal handler). This
is a problem that we already had, however.
https://bugzilla.gnome.org/show_bug.cgi?id=710367
Change the order of the arguments on the (internal) keys_changed callback in
GSettingsListenerVTable.
This means that all functions in the table now fit the following signature:
void (* f) (GObject *target,
GSettingsBackend *backend,
const gchar *name_or_path,
gpointer origin_tag,
const gchar * const *names);
allowing the possibility of arguments ignored at the end.
This allows us to simplify our dispatch-to-thread code in GSettingsBackend,
making it a bit less generic.
So far, this should be a straight refactor.
https://bugzilla.gnome.org/show_bug.cgi?id=710367
Stock GDB (both versions 7.0 and 7.1) does not come with the new
backtrace code and python API. To prevent an ugly python backtrace when
auto-loading gobject.py, let's catch the exception and not register the
FrameWrapper and the FrameFilter.
https://bugzilla.gnome.org/show_bug.cgi?id=613732
In case an object is already monitored, we lock then return without
unlocking it which can then result in a self deadlock. So properly
unlock before returning.
https://bugzilla.gnome.org/show_bug.cgi?id=721074
On x64 builds under both Visual C++ and MinGW-64, the correct symbol for
the RunDLL call is g_win32_run_session_bus, so this will silence the
annoying RunDLL error for x64 MinGW builds as well, and will allow this
call to be executed more than once.
Thanks to Tarnyko for pointing this out.
Add missing (allow-none) annotations to
g_desktop_app_info_launch_uris_as_manager(). Tested with
python -c "from gi.repository import GLib, Gio; Gio.DesktopAppInfo.new('gcalctool.desktop').launch_uris_as_manager([], None, GLib.SpawnFlags.SEARCH_PATH|GLib.SpawnFlags.STDOUT_TO_DEV_NULL, None, None, None, None)"
which is necessary to do a launch_uris() without leaking stdout.
https://launchpad.net/bugs/1259721
Remove the parts about storing up the fd's in a data structure, but call
close() on the fd's. However, retain the _get_osfhandle() check on the
fd's when we iterate through the fd's as on fd values in the iteration may
well be invalid fd's. As a result, the invalid parameter handler is still
needed for newer Microsoft CRTs (8.0/2005+) for _get_osfhandle() to
make sure that the program does not abort when we check the validity of
fd's to be closed in the loop[1].
[1]: http://msdn.microsoft.com/en-us/library/ks2530z6%28v=vs.80%29.aspx
g_source_add_child_source() releases the context lock before attaching
child_source to context. And this causes trouble if parent source is
blocked and g_main_dispatch() manages to lock the context mutex and call
unblock_source() before child_source gets attached to context.
To fix this we call g_source_attach_unlocked() before releasing the
context mutex.
https://bugzilla.gnome.org/show_bug.cgi?id=711064
GBindingTransformFunc called its arguments "source_value" and
"target_value", but in the transform_from function of a bidirectional
binding, "source_value" comes from the target object, and
"target_value" comes from the source object, which quickly gets
confusing if you need to use g_binding_get_source(), etc, in the
function.
Of course developers can call their transform function arguments
whatever they want, but many will copy from the headers/docs to start
out, so use less confusing names here ("from_value" and "to_value").
Also, fix the documentation to describe the bidirectional case
correctly.
https://bugzilla.gnome.org/show_bug.cgi?id=709440
D-Bus versions < 1.6.18 (i.e. all current versions) have a bug with the
path_namespace='/' match rule key. It should conceptually match everything,
but actually matches nothing. This results in no property change (or other)
signals being forwarded to the D-Bus client.
The work-around implemented in GDBusObjectManagerClient is to remove the
path_namespace match key if its value is ‘/’.
For the upstream D-Bus bug, see:
https://bugs.freedesktop.org/show_bug.cgi?id=70799https://bugzilla.gnome.org/show_bug.cgi?id=710726
It's not difficult to do; not all backends implement it, and for some
it may be difficult to implement query_info_on_read(), so let's just
do both.
https://bugzilla.gnome.org/show_bug.cgi?id=706254
Don't return children with invalid schemas from
g_settings_list_children() (ie: missing schemas or mismatched paths).
This prevents gsettings list-recursively from crashing when broken
schemas are installed on the system.
https://bugzilla.gnome.org/show_bug.cgi?id=705688
Recent changes to the properties testcase made invalid use of the GArray
free function. This free function takes a pointer to the item to be
freed, not the item itself. Since that item was a pointer to a GObject,
g_object_unref() was getting a GObject**, rather than a GObject*.
The use of GArray in this testcase is pretty questionable in the first
place, so just use C arrays instead.
g_cancellable_disconnect will wait until any pending "cancelled"
handlers finish. This is useful because disconnecting a handler can have the
side-effect of freeing data that the cancelled handler may rely on.
Unfortunately, the code used to enforce this synchronization between
"cancelled" handlers and g_cancellable_disconnect will also cause
deadlock if the cancelled handler itself calls g_cancellable_disconect.
Obviously, if g_cancellable_disconnect is explicitly called by a "cancelled"
handler, then the "cancelled" handler is shouldering the responsibility
of not using any data that may be freed by disconnection.
Also, g_cancellable_disconnect can be called in unexpected places by
lower layers in the code (for instance as a result of g_source_destroy).
In practice, this means it's easy for deadlocks to inadvertently crop
up when using "cancelled" handlers.
For these reasons, it would be good to fix the deadlock.
This commit prevents the deadlock by allowing foregoing synchronization,
if a pending "cancelled" handler is in the same thread as the
g_cancellabale_disconnnect call.
https://bugzilla.gnome.org/show_bug.cgi?id=705395
