Modified by Philip Withnall to omit the subdirectory and drop the
`refcount` suite as both seem like unnecessary over-categorisation.
Related to issue #1434
This avoids walking the construct params list
one extra time just to count when constructing
objects, for a small speedup of object construction
in the presence of construct params.
Move the `if` into the precondition assertion, eliminating one line of
code and making the function preconditions clearer to static analysers.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Avoid GValue transformation when we can, using
the new value_is_valid vfunc.
This is particularly useful for string properties,
where g_value_transform will make a copy of the string.
In constrast to value_validate, this one does not
modify the passed-in value, so we can avoid the cost
of copying the GValue beforehand.
It is optional, but we set it for most of the
builtin pspec types.
In several places we do paired calls of g_value_init
and g_value_unset, both of which peek the value table.
We can avoid half of that cost by remembering the value
table, instead of looking it up again.
This uses the new G_VALUE_COLLECT_INIT2 macro.
The user data parameters in callbacks need to be named user_data to
generate correct closure attributes in the introspection data. This
updates parameters missed in GNOME/glib!2633.
As noticed by Christian Hergert: We can reduce
some overhead by checking for exact type
equality first. According to Christian, around
3% of g_type_is_a calls are exact equalities.
Using prefixed property names like GtkWidget::visible
is very deprectated and basically never done. So avoid
paying the strchr cost before doing the first lookup.
Most of the time, we are dealing with static strings,
and we can compare them directly and avoid the strcmp.
Note that triggering this optimization requires
properties to be marked as G_PARAM_STATIC_NAME.
Drop the redundant `PROP_0` (which isn’t a real property) and initialise
the first member of the enum instead.
Add a typedef so that the enum type can be used in `switch` statements
in `get_property()` and `set_property()` vfuncs. This allows
`-Wswitch-enum` to be used to improve type safety.
The examples here don’t have `get_property()` or `set_property()`
vfuncs, but people might copy/paste the code to somewhere which does.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Make it a bit clearer in the documentation that using
`G_PARAM_STATIC_STRINGS` everywhere is a good thing.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Spotted by ASAN during the tests:
Direct leak of 72 byte(s) in 1 object(s) allocated from:
#0 0x7ff0b4562077 in calloc (/lib64/libasan.so.8+0xba077)
#1 0x7ff0b3e8b508 in g_malloc0 ../glib/gmem.c:155
#2 0x7ff0b375052f in g_closure_new_simple ../gobject/gclosure.c:220
#3 0x7ff0b375b422 in g_cclosure_new ../gobject/gclosure.c:976
#4 0x7ff0b37d159e in g_signal_group_connect_full ../gobject/gsignalgroup.c:790
#5 0x7ff0b37d159e in g_signal_group_connect ../gobject/gsignalgroup.c:886
#6 0x4045d8 in test_signal_group_invalid ../gobject/tests/signalgroup.c:331
#7 0x7ff0b3f369a5 in test_case_run ../glib/gtestutils.c:2930
#8 0x7ff0b3f369a5 in g_test_run_suite_internal ../glib/gtestutils.c:3018
#9 0x7ff0b3f364ed in g_test_run_suite_internal ../glib/gtestutils.c:3035
#10 0x7ff0b3f364ed in g_test_run_suite_internal ../glib/gtestutils.c:3035
#11 0x7ff0b3f37879 in g_test_run_suite ../glib/gtestutils.c:3112
#12 0x7ff0b3f37995 in g_test_run ../glib/gtestutils.c:2231
#13 0x40253c in main ../gobject/tests/signalgroup.c:664
#14 0x7ff0b2de758f in __libc_start_call_main (/lib64/libc.so.6+0x2d58f)
Direct leak of 72 byte(s) in 1 object(s) allocated from:
#0 0x7f012addf077 in calloc (/lib64/libasan.so.8+0xba077)
#1 0x7f012a708508 in g_malloc0 ../glib/gmem.c:155
#2 0x7f0129fcd52f in g_closure_new_simple ../gobject/gclosure.c:220
#3 0x7f0129fd8422 in g_cclosure_new ../gobject/gclosure.c:976
#4 0x7f012a04e5ae in g_signal_group_connect_full ../gobject/gsignalgroup.c:791
#5 0x7f012a04e5ae in g_signal_group_connect ../gobject/gsignalgroup.c:887
#6 0x4043cc in test_signal_group_invalid ../gobject/tests/signalgroup.c:308
#7 0x7f012a7b39a5 in test_case_run ../glib/gtestutils.c:2930
#8 0x7f012a7b39a5 in g_test_run_suite_internal ../glib/gtestutils.c:3018
#9 0x7f012a7b34ed in g_test_run_suite_internal ../glib/gtestutils.c:3035
#10 0x7f012a7b34ed in g_test_run_suite_internal ../glib/gtestutils.c:3035
#11 0x7f012a7b4879 in g_test_run_suite ../glib/gtestutils.c:3112
#12 0x7f012a7b4995 in g_test_run ../glib/gtestutils.c:2231
#13 0x40253c in main ../gobject/tests/signalgroup.c:664
#14 0x7f012966458f in __libc_start_call_main (/lib64/libc.so.6+0x2d58f)
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Meson generates a gdbinit file that will automatically load glib and
gobject scripts. However that script uses a helper python module that
needs PYTHONPATH to be pointing into the right location in the source
tree to be able to find glib_gdb.py and gobject_gdb.py
This won’t really affect anything, but we might as well fix them to not
crash if called with an empty `argv` by someone (ab)using `execve()`.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Much like GBindingGroup, the GSignalGroup object allows you to connect many
signal connections for an object and connect/disconnect/block/unblock them
as a group.
This is useful when using many connections on an object to ensure that they
are properly removed when changing state or disposing a third-party
object.
This has been used for years in various GNOME projects and makes sense to
have upstream instead of multiple copies.
Originally, GBindingGroup started with Builder as a way to simplify all
of the third-degree object bindings necessary around Model-Controller
objects such as TextBuffer/TextView.
Over time, it has grown to be useful in a number of scenarios outside
of Builder and has been copied into a number of projects such as GNOME
Text Editor, GtkSourceView, libdazzle, and more.
It makes sense at this point to unify on a single implementation and
include that upstream in GObject directly alongside GBinding.
Glib cannot be built statically on Windows because glib, gobject and gio
modules need to perform specific initialization when DLL are loaded and
cleanup when unloaded. Those initializations and cleanups are performed
using the DllMain function which is not called with static builds.
Issue is known for a while and solutions were already proposed but never
merged (see: https://gitlab.gnome.org/GNOME/glib/-/issues/692). Last
patch is from version 2.36.x and since then the
"constructor/destructor" mechanism has been implemented and used in
other part of the system.
This patch takes back the old idea and updates it to the last version of
glib to allow static compilation on Windows.
WARNING: because DllMain doesn't exist anymore in static compilation
mode, there is no easy way of knowing when a Windows thread finishes.
This patch implements a workaround for glib threads created by calling
g_thread_new(), so all glib threads created through glib API will behave
exactly the same way in static and dynamic compilation modes.
Unfortunately, Windows threads created by using CreateThread() or
_beginthread/ex() will not work with glib TLS functions. If users need
absolutely to use a thread NOT created with glib API under Windows and
in static compilation mode, they should not use glib functions within
their thread or they may encounter memory leaks when the thread finishes.
This should not be an issue as users should use exclusively the glib API
to manipulate threads in order to be cross-platform compatible and this
would be very unlikely and cumbersome that they may mix up Windows native
threads API with glib one.
Closes#692
Notifying during object destruction is a dubious "feature": objects
might end up recreating a bunch of state just before clearing it;
language bindings might get spurious notifications during garbage
collection runs.
We freeze the notification queue before running the dispose() chain; if
the object was temporarily vivified during dispose, we thaw the
notification queue, otherwise we let the instance clear it when we
finalize it.
See: https://gitlab.gnome.org/GNOME/gjs/-/issues/445
We now guarantee that GObjects will always be allocated at least as
aligned as the basic types. If you want to put an element in your
GObject which has higher alignment requirements, we can’t guarantee it
will be aligned*. If you need it to be aligned, you’ll need to put it on
the heap (aligned appropriately), or add appropriate padding in your
GObject struct.
*Actually, GSlice will guarantee that the whole GObject is aligned to at
least the power of 2 greater than or equal to the size of the GObject,
which means any element in the GObject struct should always be
appropriate aligned if the compiler pads it appropriately. If malloc()
is used, however, it doesn’t make that guarantee, so we can’t make that
guarantee overall.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1231
Regardless of the actual alignment of the GTypeInstance in question,
these do a runtime check on the type, so if the type was originally
aligned correctly when allocated, it should be aligned correctly if the
type check succeeds. -Wcast-align is meant to warn about casts between
types, which this isn’t (if the check succeeds).
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1231
See the reasoning in the patch for why we believe GObjects *are*
(already) as aligned as the basic types.
We want to make this guarantee so that it’s guaranteed to be safe for
people to ignore -Wcast-align warnings for GObjects which contain basic
types. This typically happens with gdouble on 32-bit ARM platforms.
The checks are slightly complicated by the need to support GObjects with
custom constructors. We should expect that a custom construction
function will chain up to g_object_constructor (which calls
g_type_create_instance() as normal), but it’s possible that someone has
done something crazy and uses a custom allocator which doesn’t return
with the same alignment as GSlice. Hand them a warning in that case. If
that is true, the code which uses their custom-constructed GObject can
presumably already deal with the alignment it gets given.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1231
This should remove some warnings from the CI, making it easier to see
legitimate CI failures.
For example, see https://gitlab.gnome.org/GNOME/glib/-/jobs/1621041.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
When an object with toggle reference is notifying a change we just
assume that this is true because of previous checks.
However, while locking, another thread may have removed the toggle
reference causing the waiting thread to abort (as no handler is set at
that point).
To avoid this, once we've got the toggle references mutex lock, check
again if the object has toggle reference, and if it's not the case
anymore just ignore the request.
Add a test that triggers this, it's not 100% happening because this is
of course timing related, but this is very close to the truth.
Fixes: #2394
The previous wording was not clear about what happens if a new weak ref
is taken during disposal (shortly after resurrecting the object with a
new strong ref, otherwise taking the weak ref is invalid).
See: https://gitlab.gnome.org/GNOME/glib/-/merge_requests/2064/diffs#note_1270092
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2390
No need to call memset in the loop, we can just
initialize all the values in one go.
GtkBuilder is now using g_object_setv, so this
may improve application start times a bit.
As per the previous change, an object that had weak locations set may
need to lock again the weak locations mutex during qdata cleanup, but
we can avoid this when we know we're removing the last location, by
removing the qdata entry and freeing the data.
In case a new location is needed for the same object, new data will be
added.
However, by doing this the weak locations during dispose may be
invalidated once the weak locations lock is passed, so check again if
this is the case while removing them.
It can happen that a GWeakRef is added to an object while it's disposing
(or even during finalizing) and this may happen in a thread that (weak)
references an object while the disposal isn't completed yet or when
using toggle references and switching to GWeakRef on notification (as
the API suggests).
In such scenario the weak locations are not cleaned up when the object
is finalized, and will point to a free'd area.
So, during finalization and when we're sure that the object will be
destroyed for sure, check again if there are new weak locations and
unset them if any as part of the qdata destruction.
Do this adding a new utility function so that we can avoid duplicating
code to free the weak locations.
Added various tests simulating this case.
Fixes: #2390
The documentation sort of already said this, but it’s better to make it
explicit.
This avoids the situation where some of the weak notify callbacks for an
object have been called, and then a subsequent one resurrects the
object. Without some way of undoing the weak notifications already sent,
that would leave external state which is coupled to the object’s
lifecycle out of sync.
This arose from discussion on !2064.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
GTK currently checks if a GtkWidget is finalized while still using a
floating reference—i.e. a widget was disposed without any parent
container owning it.
This warning can be useful to identify and trace ownership transfer
issues in libraries using initially unowned floating object types.
To avoid introducing constraints ex post, we can gate this check behind
both the G_ENABLE_DEBUG compile time flag for GLib, and behind the
G_ENABLE_DIAGNOSTIC environment variable run time check.
Fixes: #2489
When rendering the contents of the GLib documentation stored inside the
introspection data, a common behaviour is to take the first paragraph as
a summary of the symbol being documented.
The documentation is assumed to be in Markdown format, which means:
- paragraphs must be separated by newlines
- lines that have an indentation of four or more spaces are considered
code blocks
- lines that start with a `#` are considered titles
This means we need to slightly tweak the documentation in our sources to
ensure that it can be rendered appropriately by tools that are not
gtk-doc.
See issue: #2365
We want to have the ability to mark types that should not be derivable
even if they are in a deeply derivable type hierarchy; in other words,
leaf nodes in the types tree.
This works in the same way as g_variant_take_ref(), and for the same
reason.
Updated and Rebased by Nitin Wartkar <nitinwartkar58@gmail.com>
Closes#1112
gjs has some situations where it's not always aware of the @data that
was passed into g_object_add_toggle_ref, so allow passing %NULL to
just match on @notify.
Rebased and updated by Nitin Wartkar
Closes#817
It is cleaner to define glib_typeof() in a header included after
gversionmacros.h so we can use GLIB_VERSION_MIN_REQUIRED directly
instead of doing it everywhere glib_typeof() is used.
Include the base URI in the `g_test_bug()` calls instead. This resolves
inconsistencies between the old bug base (bugzilla.gnome.org) and the
new bug base (gitlab.gnome.org). It also has the advantage that the URI
passed to `g_test_bug()` is now clickable in the code editor, rather
than being split across two locations.
See https://gitlab.gnome.org/GNOME/glib/-/merge_requests/275#note_303175
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Teach `glib-mkenums` how to parse and ignore:
- `GLIB_AVAILABLE_ENUMERATOR_IN_x_xx`
- `GLIB_DEPRECATED_ENUMERATOR_IN_x_xx`
- `GLIB_DEPRECATED_ENUMERATOR_IN_x_xx_FOR(x)`
Future work could expose the deprecation/availability information as
substitutions in the template file, but this commit does not do that.
It does, however, add some unit tests for the annotations.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Fixes: #2327
Close output file to ensure all buffered output actually gets written.
Otherwise, glib-genmarshal output is sometimes empty (for example, when trying
to build gdk-pixbuf on Windows, with Meson installed from .msi package).
argparse.FileType doesn't get closed automagically when the script exits:
https://bugs.python.org/issue13824
Fixes https://gitlab.gnome.org/GNOME/glib/-/issues/2341
When included inside an `extern "C"` block, this causes build failures
that look something like:
/usr/include/c++/10/type_traits:2930:3: error: template with C linkage
2930 | template<typename _Fn, typename... _Args>
| ^~~~~~~~
../../disas/arm-a64.cc:20:1: note: ‘extern "C"’ linkage started here
20 | extern "C" {
| ^~~~~~~~~~
Commit 4273c43902 made this opt in for
projects which are defining `GLIB_VERSION_MIN_REQUIRED`, but the include
of `<type_traits>` via `gmacros.h` was not included in this. If we move
the include out to the places where `glib_typeof` is called, we can make
it covered by this macro too, and save a few consumers from FTBFSing.
That also means that, if you don't want to fix your use of the headers,
and as long as this version is sufficient for you, a quick workaround is
to define `GLIB_VERSION_MIN_REQUIRED` to `GLIB_VERSION_2_66` or lower.
Suggested by Simon McVittie.
Alternative to: https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1935
Fixes: https://gitlab.gnome.org/GNOME/glib/-/issues/2331
Convert all the call sites which use `g_memdup()`’s length argument
trivially (for example, by passing a `sizeof()`), so that they use
`g_memdup2()` instead.
In almost all of these cases the use of `g_memdup()` would not have
caused problems, but it will soon be deprecated, so best port away from
it.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
We have a "good" implementation of g_clear_signal_handler() in
form of a macro. Use it, and don't duplicate the code.
Also add a comment to the documentation that "instance" in fact must
not point to a valid GObject instance -- if the handler ID is unset.
Also reword the documentation about the reasoning for why a macro
version exists. The reason is not to use the function "without
pointer cast". I don't think the non-macro version requires any
pointer cast, since "instance" is a void pointer. Was this referring
to the handler_id_ptr? That doesn't seem right either, because the
caller should always provide a "gulong *" pointer and nothing else.
Preferably macros behave function-like to minimize surprises. That
means for example that they evaluate all arguments exactly once.
Rework g_clear_signal_handler() to assign the macro parameters
to auto variables so they are accessed exactly once.
Also, drop the static assert for the size of (*handler_id_ptr).
As we now assign to a "gulong *" pointer, the compiler already
checks the types. In fact, the check is now stricter than before.
Previously it would have allowed a pointer to a "signed long".
This is a change in behavior of the macro and the stricter compile
check could cause a build failure with broken code.
Also, clear the handler id first, before calling
g_signal_handler_disconnect(). Disconnecting a signal invokes the
destroy notify, which can have side effects. It just feels cleaner
to first reset the *_handler_id_ptr, before those side effects
can happen. Of course, in practice it makes little difference.
g_signal_new_valist() is called by g_signal_new(), which is probably
the most common way to create a signal.
Also, in almost all cases is the number of signal parameters small.
Let's optimize for that by using a stack allocated buffer if we have
few parameters.
That changes the return type of functions like g_object_ref() that can
break C++ applications like Webkit. Note that it is not an ABI break.
It must thus be opt-in the same way we did when adding this to
g_object_ref() for GNU C compilers in the first place. Unfortunately it
cannot be done directly in gmacros.h because GLIB_VERSION_2_68 is not
defined there, and gversionmacros.h cannot be included there because
there is some strict ordering in which those headers must be included.
This means that applications that does not define
GLIB_VERSION_MIN_REQUIRED will still get an API break, so we encourage
them to declare their minimum requirement to avoir such issues in the
future too.
This change was previously implemented in
9ba17d511e but got dropped during the
Python conversion of the Perl script.
See the commit message of this commit as well as
https://bugzilla.gnome.org/show_bug.cgi?id=782162
for more information.
This patch also adds a new test so we don't loose this feature again.
Also adds a test that checks that the G_SIGNAL_RUN flags are handled
correctly and the class signal handler is called at the right times.
Fixes https://gitlab.gnome.org/GNOME/glib/issues/513
gobject/tests/ifaceproperties.c: In function ‘base_object_get_type’:
gobject/tests/ifaceproperties.c:321:1: error: missing initializer for field ‘value_table’ of ‘GTypeInfo’ {aka ‘const struct _GTypeInfo’}
321 | static DEFINE_TYPE_FULL (BaseObject, base_object,
| ^~~~~~
In file included from gobject/gobject.h:24,
from gobject/gbinding.h:29,
from glib/glib-object.h:22,
from gobject/tests/ifaceproperties.c:21:
gobject/gtype.h:1063:26: note: ‘value_table’ declared here
1063 | const GTypeValueTable *value_table;
| ^~~~~~~~~~~
gobject/tests/ifaceproperties.c: In function ‘test_iface_get_type’:
gobject/tests/ifaceproperties.c:144:1: error: missing initializer for field ‘class_finalize’ of ‘GTypeInfo’ {aka ‘const struct _GTypeInfo’}
144 | static DEFINE_IFACE (TestIface, test_iface, NULL, test_iface_default_init)
| ^~~~~~
In file included from gobject/gobject.h:24,
from gobject/gbinding.h:29,
from glib/glib-object.h:22,
from gobject/tests/ifaceproperties.c:21:
gobject/gtype.h:1054:26: note: ‘class_finalize’ declared here
1054 | GClassFinalizeFunc class_finalize;
| ^~~~~~~~~~~~~~
gobject/tests/signals.c: In function ‘test_introspection’:
gobject/tests/signals.c:1180:17: error: comparison of integer expressions of different signedness: ‘gint’ {aka ‘int’} and ‘guint’ {aka ‘unsigned int’}
1180 | for (i = 0; i < n_ids; i++)
| ^
gobject/tests/properties.c: In function ‘properties_get_property’:
gobject/tests/properties.c:562:17: error: comparison of integer expressions of different signedness: ‘int’ and ‘long unsigned int’
562 | for (i = 0; i < G_N_ELEMENTS (test_props); i++)
| ^
gobject/tests/properties.c:583:17: error: comparison of integer expressions of different signedness: ‘int’ and ‘long unsigned int’
583 | for (i = 0; i < G_N_ELEMENTS (test_props); i++)
| ^
gobject/tests/dynamictests.c: In function ‘test_module_get_type’:
gobject/tests/dynamictests.c:97:7: error: missing initializer for field ‘value_table’ of ‘GTypeInfo’ {aka ‘const struct _GTypeInfo’}
97 | };
| ^
In file included from gobject/gobject.h:24,
from gobject/gbinding.h:29,
from glib/glib-object.h:22,
from gobject/tests/dynamictests.c:23:
gobject/gtype.h:1063:26: note: ‘value_table’ declared here
1063 | const GTypeValueTable *value_table;
| ^~~~~~~~~~~
gobject/gparam.c: In function ‘g_param_type_register_static’:
gobject/gparam.c:1434:3: error: missing initializer for field ‘value_table’ of ‘GTypeInfo’ {aka ‘struct _GTypeInfo’}
1434 | };
| ^
In file included from gobject/gvalue.h:26,
from gobject/gparam.h:26,
from gobject/gparam.c:26:
gobject/gtype.h:1063:26: note: ‘value_table’ declared here
1063 | const GTypeValueTable *value_table;
| ^~~~~~~~~~~
gobject/gtypemodule.c: In function ‘g_type_module_get_type’:
gobject/gtypemodule.c:154:7: error: missing initializer for field ‘value_table’ of ‘GTypeInfo’ {aka ‘const struct _GTypeInfo’}
154 | };
| ^
In file included from gobject/gtypeplugin.h:24,
from gobject/gtypemodule.c:22:
gobject/gtype.h:1063:26: note: ‘value_table’ declared here
1063 | const GTypeValueTable *value_table;
| ^~~~~~~~~~~
gobject/gtypeplugin.c: In function ‘g_type_plugin_get_type’:
gobject/gtypeplugin.c:91:7: error: missing initializer for field ‘class_init’ of ‘GTypeInfo’ {aka ‘const struct _GTypeInfo’}
91 | };
| ^
In file included from gobject/gtypeplugin.h:24,
from gobject/gtypeplugin.c:20:
gobject/gtype.h:1053:26: note: ‘class_init’ declared here
1053 | GClassInitFunc class_init;
| ^~~~~~~~~~
gobject/gtype.c: In function ‘iface_node_has_available_offset_L’:
gobject/gtype.c:1288:42: error: comparison of integer expressions of different signedness: ‘gsize’ {aka ‘long unsigned int’} and ‘int’
1288 | if (G_ATOMIC_ARRAY_DATA_SIZE (offsets) <= offset)
| ^~
The version of `black` on the CI server wanted these changes. Make them
to keep the `style-check-diff` CI job from constantly failing.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
This commit only looks at the `Returns:` lines in the documentation, and
has examined all of them in the file. Function arguments have not been
checked.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2227
This commit only looks at the `Returns:` lines in the documentation, and
has examined all of them in the file. Function arguments have not been
checked.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2227
This commit only looks at the `Returns:` lines in the documentation, and
has examined all of them in the file. Function arguments have not been
checked.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2227
When this is called on the source or target, the weak notify of the
corresponding object is called without the GWeakRef being cleared.
See https://gitlab.gnome.org/GNOME/glib/-/issues/2266 for that issue.
This means that a strong reference to these zombie objects can be
retrieved from the GWeakRefs and the previous assumption that this can't
happen was wrong. Remove the assertion for that accordingly and handle
this case.
Specifically, all signal handlers and weak notifies of the object are
already gone and must not be disconnected/removed a second time, or
otherwise memory corruption would be caused. Instead just set the
GWeakRef to NULL and handle it otherwise as if the GWeakRef didn't give
a strong reference to begin with.
Fixes https://gitlab.gnome.org/GNOME/glib/-/issues/2265
This especially has the effect that any GWeakRefs to the object will not
necessarily be set to NULL yet if called as part of
g_object_run_dispose() and not as part of g_object_unref().
gobject/tests/value.c: In function ‘test_valuearray_basic’:
gobject/tests/value.c:253:17: error: comparison of integer expressions of different signedness: ‘gint’ {aka ‘int’} and ‘guint’ {aka ‘unsigned int’}
253 | for (i = 0; i < a->n_values - 1; i++)
| ^
gobject/tests/value.c:257:17: error: comparison of integer expressions of different signedness: ‘gint’ {aka ‘int’} and ‘guint’ {aka ‘unsigned int’}
257 | for (i = 0; i < a->n_values; i++)
| ^
This was inconsistently handled before and only explicit unbinding or
finalizing the binding would've previously released the transform
function. If the source/target were finalized while more strong
references to the binding still existed then the transform function
would stay alive and only the binding itself would be deactivated.
Unbinding can happen from one thread while a property notification is
being handled concurrently in another one.
To solve this, introduce a reference counter for the transform function
that ensures that it always stays valid while in use and protect access
to the one stored inside the binding with the unbind mutex.
It's possible for g_binding_unbind() to be called at the same time as
one (or both) of source and target are being finalized. The resulting
unbinding needs to be protected with a mutex to ensure that it only
happens exactly once.
As the first reference is owned by both weak notifies and the caller of
g_object_bind_property(), additional indirections are needed to ensure that
unreffing the first reference after creation still unbinds the binding
as before. This seems to be a common code pattern and how this was
intended to be used, but is only safe in single-threaded contexts as it
relies on both the source and target object to be still alive.
Add a lot of comments to the code about all these dependencies and a
couple of assertions to ensure they hold valid.
Also document that inconsistent reference ownership handling of
g_binding_unbind() that makes it unfit for automatically generated
language bindings.
