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.
gobject/gobject.c: In function ‘g_object_new_internal’:
gobject/gobject.c:1962:25: error: comparison of integer expressions of different signedness: ‘gint’ {aka ‘int’} and ‘guint’ {aka ‘unsigned int’}
1962 | for (j = 0; j < n_params; j++)
| ^
gobject/gobject.c:1989:21: error: comparison of integer expressions of different signedness: ‘gint’ {aka ‘int’} and ‘guint’ {aka ‘unsigned int’}
1989 | for (i = 0; i < n_params; i++)
| ^
gobject/gobject.c: In function ‘g_object_new_with_custom_constructor’:
gobject/gobject.c:1836:21: error: comparison of integer expressions of different signedness: ‘gint’ {aka ‘int’} and ‘guint’ {aka ‘unsigned int’}
1836 | for (j = 0; j < n_params; j++)
| ^
gobject/gobject.c:1914:17: error: comparison of integer expressions of different signedness: ‘gint’ {aka ‘int’} and ‘guint’ {aka ‘unsigned int’}
1914 | for (i = 0; i < n_params; i++)
| ^
gobject/gobject.c: In function ‘g_object_class_install_properties’:
gobject/gobject.c:766:17: error: comparison of integer expressions of different signedness: ‘gint’ {aka ‘int’} and ‘guint’ {aka ‘unsigned int’}
766 | for (i = 1; i < n_pspecs; i++)
| ^
gobject/gtype.c: In function ‘g_type_interface_add_prerequisite’:
gobject/gtype.c:1607:21: error: comparison of integer expressions of different signedness: ‘guint’ {aka ‘unsigned int’} and ‘int’
1607 | for (i = 0; i < prerequisite_node->n_supers + 1; i++)
| ^
The problem occurs because we keep a pointer inside the allocated block,
instead of a pointer to the start of the block. This memory exists for
the lifetime of the application, so let's silence it.
This is probably abuse of VALGRIND_MALLOCLIKE_BLOCK(), which is really
intended for use in memory allocators, but gtype.c already uses it in
two other places, and it's a practical solution. I wrote another larger
fix for this issue that involves keeping an array of extra pointers when
running under valgrind. This is simpler.
Fix suggested by Philip Withnall
```
==180238== 16 bytes in 1 blocks are possibly lost in loss record 3,078 of 16,075
==180238== at 0x483BB1A: calloc (vg_replace_malloc.c:762)
==180238== by 0x5489495: g_malloc0 (gmem.c:132)
==180238== by 0x5489754: g_malloc0_n (gmem.c:364)
==180238== by 0x53FDBEE: type_set_qdata_W (gtype.c:3722)
==180238== by 0x53FDEE8: type_add_flags_W (gtype.c:3787)
==180238== by 0x53FC348: g_type_register_fundamental (gtype.c:2662)
==180238== by 0x53D969B: _g_enum_types_init (genums.c:124)
==180238== by 0x53FF058: gobject_init (gtype.c:4432)
==180238== by 0x53FF082: gobject_init_ctor (gtype.c:4493)
==180238== by 0x4010F29: call_init.part.0 (dl-init.c:72)
==180238== by 0x4011030: call_init (dl-init.c:30)
==180238== by 0x4011030: _dl_init (dl-init.c:119)
==180238== by 0x4002149: ??? (in /usr/lib64/ld-2.30.so)
```
Fixes#2076
The problem occurs because we keep a pointer inside the allocated block,
instead of a pointer to the start of the block:
```
==180238== 16 bytes in 1 blocks are possibly lost in loss record 3,086 of 16,075
==180238== at 0x483980B: malloc (vg_replace_malloc.c:309)
==180238== by 0x548942C: g_malloc (gmem.c:102)
==180238== by 0x54A4748: g_slice_alloc (gslice.c:1025)
==180238== by 0x53D0AAF: freelist_alloc (gatomicarray.c:77)
==180238== by 0x53D0B85: _g_atomic_array_copy (gatomicarray.c:133)
==180238== by 0x53F8E6D: iface_node_set_offset_L (gtype.c:1347)
==180238== by 0x53F91F1: type_node_add_iface_entry_W (gtype.c:1444)
==180238== by 0x53F93DF: type_add_interface_Wm (gtype.c:1477)
==180238== by 0x53FC946: g_type_add_interface_static (gtype.c:2852)
==180238== by 0x4A3D53A: gtk_menu_shell_accessible_get_type_once (gtkmenushellaccessible.c:26)
==180238== by 0x4A3D495: gtk_menu_shell_accessible_get_type (gtkmenushellaccessible.c:26)
==180238== by 0x4C8AC44: gtk_menu_shell_class_init (gtkmenushell.c:424)
```
Note we cannot use VALGRIND_FREELIKE_BLOCK() in freelist_free() because we
have not actually freed the FreeListNode and need to dereference it in
freelist_alloc() to decide whether to reuse the block. That would result
in a use-after-free warning before we would get a chance to call
VALGRIND_MALLOCLIKE_BLOCK() in the reuse path.
Also note that this free list only ever grows: it never shrinks for the
lifetime of the application, so nothing here will ever be truely freed,
although unused elements are eligible for reuse.
Fix suggested by Philip Withnall
Related: #2076
gobject/gtype.c: In function ‘type_node_add_iface_entry_W’:
gobject/gtype.c:1379:21: error: comparison of integer expressions of different signedness: ‘guint’ {aka ‘unsigned int’} and ‘int’
1379 | for (i = 0; i < num_entries; i++)
| ^
gobject/gtype.c: In function ‘lookup_iface_entry_I’:
gobject/gtype.c:599:17: error: comparison of integer expressions of different signedness: ‘int’ and ‘long unsigned int’
599 | if (index < IFACE_ENTRIES_N_ENTRIES (entries))
| ^
gobject/gatomicarray.h:51:8: note: in definition of macro ‘G_ATOMIC_ARRAY_DO_TRANSACTION’
51 | {_C_;} \
| ^~~
