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.
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_;} \
| ^~~
Half of the references to `init_state` in `gtype.c` already correctly
accessed it atomically, but a couple didn’t. Drop the `volatile`
qualifier from its declaration, as that’s not necessary for atomic
access.
Note that this is the `init_state` in `TypeData`, *not* the `init_state`
in `IFaceEntry`.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #600
These variables were already (correctly) accessed atomically. The
`volatile` qualifier doesn’t help with that.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #600
This is an API break, but no third party code should be touching
`GObject.ref_count`, let alone in a way which would be changed by the
removal of the `volatile` qualifier.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #600
This is an API break, but it should not affect third party code since
that code should not be interacting with the `data` member in a way that
invokes its `volatile` qualifier (such as copying to an intermediate
variable).
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #600
These variables were already (correctly) accessed atomically. The
`volatile` qualifier doesn’t help with that.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #600
http://isvolatileusefulwiththreads.in/c/
It’s possible that the variables here are only marked as volatile
because they’re arguments to `g_once_*()`. Those arguments will be
modified in a subsequent commit.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #600
The previous code consumed a larger additional amount of stack space.
That is because it would allocate the temporary buffer for GValues on
the stack with "g_newa (GValue, 1)" and thus the required stack
space grew with the number of arguments. Granted, this is already
a variadic C function, so the caller already placed that many elements
on the stack. For example, on the stack there are the property names
and the pointers to the arguments, which should amount to roughly
O(n_args * 16) (on 64 bit, with pointers being 8 bytes large).
That is not bad, because it means in the previous version the stack space
would grow linear with the already used stack space. However, a GValue is
an additional 24 bytes (on 64 bit), which probably more than doubles the
required stack space. Let's avoid that, by allocating the temporary list
on the heap after a certain threshold. This probably more than doubles the
number of possible arguments before the stack overflows.
Also, previously the heap allocated "params" array only grew one element
per iteration. Of course, it is likely that libc anyway reallocates
the buffers by growing the space exponentially. So realloc(ptr, 1)
probably does not O() scale worse than doubling the buffer sizes ourselves.
However, it seems clearer to keep track of the allocated sizes ourself, and
only call realloc() when we determine that we are out of space.
Especially because we need to update the value pointers on reallocation.
Note that we now require a heap allocation both for the "params" and the
"values" list. Theoretically that could be combined by using one buffer
for both. But that would make the code more complicated.
Now we pre-allocate buffers for 16 elements on the stack. That
is (16 * (16 + 24) bytes (or 640 bytes) on the stack. I think that
is still acceptable.
Two out of three callers pass the count argument from a variable
of type guint. And the third is currently an always positive gint.
We should use the correct integer type that matches the type as it
used otherwise.
This commit is the unmodified results of running
```
black $(git ls-files '*.py')
```
with black version 19.10b0. See #2046.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Add a test for a signal returning interface types, using
the generic marshaller. This will hopefully exercise newly
added code in value_from_ffi_type().
This tests the new functionality that
g_type_interface_instantiable_prerequisite
was added for.
Before the changes, this fails with
GObject-WARNING **: Unable to convert a value of type \
GObject to a value of type Foo
We do the same test with g_object_bind_property_with_closures
as well, to exercise g_cclosure_marshal_generic.
Use the new g_type_interface_instantiable_prerequisite() to check
compatibility for transform functions.
In particular, this allows interfaces (in my case GDK_TYPE_PAINTABLE) to
be transformed to/from any GObject type (in my case G_TYPE_OBJECT) using
the transform function registered to transform between any 2 objects
(g_value_object_transform_value() does a type check and uses NULL if the
types don't match).
And this in turn allows be to g_object_bind_property() a gobject-typed
generic property (GtkListItem::item) to a GtkImage::paintable.
Tests for the new functionality are included.
Use the newly added g_type_interface_instantiable_prerequisite() to
allow closure return values being interfaces by looking up the
instantiable type for the interface and using its GValue accessors.
This function returns the most specific instantiatable type
that is a prerequisite for a given interface.
This type is necessary in particular when dealing with GValues
because a GValue contains an instance of a type.
This commit includes tests for the new API.
Rather than using a mixture of ‘instantiable’ and ‘instantiatable’
everywhere, standardise on the term which is already in the public API.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
g_has_typeof macro is wrongly in the public g_ namespace, internaly
symbols are usually in the glib_ namespace. This will also allow to
define glib_typeof differently on non-GNUC compilers (e.g. c++11
decltype).
commit 916297be79 added a hash table
to provide constant time lookups of signal handlers.
Unfortunately, that commit neglected to remove handlers from
g_signal_connect_object calls from the hash table that are
disconnected implicitly when the associated object goes away.
This commit addresses that bug by changing the closure invalidate
handler associated with the signal connection to properly remove the
handler from the hash table.
It may be defined by the environment (we document that as being allowed)
— if so, individual files should not try to redefine it, as that causes
a preprocessor warning.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Add a set of new URI parsing and generating functions, including a new
parsed-URI type GUri. Move all the code from gurifuncs.c into guri.c,
reimplementing some of those functions (and
g_string_append_uri_encoded()) in terms of the new code.
Fixes:
https://gitlab.gnome.org/GNOME/glib/issues/110
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
The G_VALUE_NOCOPY_CONTENTS for strings can only be used when collecting them
and not when copying them.
Instead only avoid copies for strings that are interned.
Fixes#2141
This was mostly machine generated with the following command:
```
codespell \
--builtin clear,rare,usage \
--skip './po/*' --skip './.git/*' --skip './NEWS*' \
--write-changes .
```
using the latest git version of `codespell` as per [these
instructions](https://github.com/codespell-project/codespell#user-content-updating).
Then I manually checked each change using `git add -p`, made a few
manual fixups and dropped a load of incorrect changes.
There are still some outdated or loaded terms used in GLib, mostly to do
with git branch terminology. They will need to be changed later as part
of a wider migration of git terminology.
If I’ve missed anything, please file an issue!
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Some editors automatically remove trailing blank lines, or
automatically add a trailing newline to avoid having a trailing
non-blank line that is not terminated by a newline. To avoid unrelated
whitespace changes when users of such editors contribute to GLib,
let's pre-emptively normalize all files.
Unlike more intrusive whitespace normalization like removing trailing
whitespace from each line, this seems unlikely to cause significant
issues with cherry-picking changes to stable branches.
Implemented by:
find . -name '*.[ch]' -print0 | \
xargs -0 perl -0777 -p -i -e 's/\n+\z//g; s/\z/\n/g'
Signed-off-by: Simon McVittie <smcv@collabora.com>
The various `g_strdup_printf()` returns values in the implementations of GValue
lcopy_func are runtime checks which could be disabled if one wants and therefore
should be handled as such with g_return_val_if_fail()
The property strings are interned already, so this potentially allows for faster
comparisons. The property strings were already not copied, as they were tagged
as static.
This adds support to be able to explicitely stored interned strings into
G_TYPE_STRING GValue.
This is useful for cases where the user:
* *knows* the string to be stored in the GValue is canonical
* Wants to know whther the string stored is canonical
This allows:
* zero-cost GValue copy (the content is guaranteed to be unique and exist
throughout the process life)
* zero-cost string equality checks (if both string GValue are interned, you just
need to check the pointers for equality or not, instead of doing a strcmp).
Fixes#2109
The glib-mkenums program allows generating code to handle enums/flags
with very different purposes. One of its purposes could be generating
per-enum/flag methods to be exposed in a library API, and while doing
that, it would be nice to have a way to specify in which API version
the enum/flag was introduced, so that the same version could be shown
in the generated API methods.
E.g. From the following code:
/**
* QmiWmsMessageProtocol:
* @QMI_WMS_MESSAGE_PROTOCOL_CDMA: CDMA.
* @QMI_WMS_MESSAGE_PROTOCOL_WCDMA: WCDMA.
*
* Type of message protocol.
*
* Since: 1.0
*/
typedef enum { /*< since=1.0 >*/
QMI_WMS_MESSAGE_PROTOCOL_CDMA = 0x00,
QMI_WMS_MESSAGE_PROTOCOL_WCDMA = 0x01
} QmiWmsMessageProtocol;
The template would allow us to generate a method documented like this,
including the Since tag with the value given in the mkenums 'since' tag.
/**
* qmi_wms_message_protocol_get_string:
* @val: a QmiWmsMessageProtocol.
*
* Gets the nickname string for the #QmiWmsMessageProtocol specified at @val.
*
* Returns: (transfer none): a string with the nickname, or %NULL if not found. Do not free the returned value.
* Since: 1.0
*/
const gchar *qmi_wms_message_protocol_get_string (QmiWmsMessageProtocol val);
Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Meson 0.54.0 added a new method meson.override_dependency() that must be
used to ensure dependency consistency. This patch ensures a project that
depends on glib will never link to a mix of system and subproject
libraries. It would happen in such cases:
The system has glib 2.40 installed, and a project does:
dependency('glib-2.0', version: '>=2.60',
fallback: ['glib', 'glib_dep'])
dependency('gobject-2.0')
The first call will configure glib subproject because the system libglib
is too old, but the 2nd call will return system libgobject.
By overriding 'gobject-2.0' dependency while configuring glib subproject
during the first call, meson knows that on the 2nd call it must return
the subproject dependency instead of system dependency.
This also has the nice side effect that with Meson >0.54.0 an
application depending on glib can declare the fallback without knowing
the dependency variable name: dependency('glib-2.0', fallback: 'glib').
The __declspec(dllexport) attribute in itself doesn't imply
'extern' - thus any intended variable declaration with
GLIB_VAR/GOBJECT_VAR would actually be a variable definition. With
C compilers defaulting to -fcommon, this isn't an issue, but
upcoming compilers (GCC 10 and Clang 11) will default to -fno-common,
ending up with duplicate definitions of these variables.
Rename the variables involved so that people get a slightly more
obvious critical warning when they try to ref an object which has
already been finalised.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Making this validation code public allows projects to validate a
GParamSpec name before creating it. While hard-coded GParamSpec don't
need this, we can't afford crashing the main program for dynamically
generated GParamSpec from user-created data.
In such case, we will need to validate the param names and return errors
instead of trying to create a GParamSpec with invalid names.
Includes modifications from Philip Withnall and Emmanuele Bassi to
rearrange the new function addition and split it into one function for
GParamSpecs and one for GSignals.
When calling `g_set_object()` for a type derived from `GObject`, GCC 9.2
was giving the following strict aliasing warning:
```
../../source/malcontent/libmalcontent-ui/user-controls.c:1001:21: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
1001 | if (g_set_object (&self->user, user))
/opt/gnome/install/include/glib-2.0/gobject/gobject.h:744:33: note: in definition of macro ‘g_set_object’
744 | (g_set_object) ((GObject **) (object_ptr), (GObject *) (new_object)) \
| ^~~~~~~~~~
```
This was due to the `(GObject **)` cast.
Pass the pointer through a union to squash this warning. We already do
some size and type checks of the dereferenced type, which should catch
casual errors. The `g_object_ref()` and `g_object_unref()` calls which
subsequently happen inside the `g_set_object()` function also do some
dynamic type checks.
Add a test.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
As with `g_variant_new()` (or any varargs function which takes integer
literals of differing widths), callers need to be careful to ensure
their integer literals have the right width.
Tweak the documentation for `g_object_new()`, `g_object_set()` and
`g_object_get()` to clarify this. The documentation for `g_object_get()`
shows that it is not subject to the same caveats, since it operates on
pointers.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Closes: #833
While we automatically define cleanup functions for the module, we don't
do it for the module class.
This will allow to manage the ownership of the class when reffing it
without having to cast it to GTypeClass.
The `G_TYPE_IS_INSTANTIATABLE()` check is redundant with a precondition
on the function.
The `g_type_class_peek()` check seems like a pointless restriction: it
should be possible to check for a signal from a class init function.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #650
Use the new g_type_interface_instantiable_prerequisite() to check
compatibility for transform functions.
In particular, this allows interfaces (in my case GDK_TYPE_PAINTABLE) to
be transformed to/from any GObject type (in my case G_TYPE_OBJECT) using
the transform function registered to tranform between any 2 objects
(g_value_object_transform_value() does a type check and uses NULL if the
types don't match).
And this in turn allows be to g_object_bind_property() a gobject-typed
generic property (GtkListItem::item) to a GtkImage::paintable.
Use the newly added g_type_interface_instantiable_prerequisite() to
allow closure return values being interfaces by looking up the
instantiable type for the interface and usings its GValue accessors.
There is (at most) a single GType that is instantiable and a
prerequisite for an interface. This function returns that type.
This type is necessary in particular when dealing with GValues because a
GValue contains an instance of a type.
