This is a partial revert of commit fa8c7c0da using the approach
suggested (and tested) by Kjell Ahlstedt.
It is intended to be temporary pending a proper dig into what’s causing
the regression, just so we can get the 2.73.1 release out.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2672
Coverity notices the `g_object_unref()` call in `g_object_notify()`, but
not the paired `g_object_ref()` call. It therefore incorrectly assumes
that every call to `g_object_notify()` frees the object. This causes a
lot (hundreds) of false positive reports about double-frees or
use-after-frees.
I can’t find a way to fix this using a model file, so the other options
are:
* Manually mark every report as a false positive and keep updating them
as the code changes over time. This would take a lot of maintainer
effort.
* Comment out the `g_object_ref()`/`g_object_unref()` calls when
running static analysis (but not in a normal production build). This
is ugly, but cheap and shouldn’t impact maintainability much.
So this commit implements option 2.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
This prevents `-Wunused-function` warnings on platforms which don’t have
`HAVE_OPTIONAL_FLAGS` defined.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
g_object_new_with_custom_constructor needs to handle
freezing notifications in the same way as
g_object_new_internal.
Fixing a bug pointed out by Christian Hergert.
The corner-case we are handling here is that
we don't freeze the notify queue in g_object_init
(because there's no custom ->notify vfunc, but
then we gain a notify handler during instance
init, and instance init also triggers a
notification. Handle this by jit freezing
notification in g_object_notify_by_spec_internal.
Note that this is bad code - instance init really
shouldn't be doing things like this.
Testcase included.
Fixes: #2665
We need to match the conditions in g_object_init
for when we already have a freeze. Without that,
we underflow the freeze count and trigger a
warning.
Fixes: #2666
When the param specs are provided as an array
with g_object_class_install_properties, keep
a copy of that array around and use it for
looking up properties without the param spec
pool.
Note that this is an opportunistic optimization -
currently, it only works for properties of the
class itself, not for parent classes, and it
only works if the property names are identical
string literals (we're at the mercy of the linker
for that).
If we don't get lucky, we fall back to using
the pspec pool as usual.
This may fix Coverity assuming that pspecs are leaked, which is causing
tens and tens of false positives in the latest Coverity reports for
GLib.
Ensure that the pspecs are sunk (if floating) even if adding them to the
class fails (due to validation failure or an identically named property
already existing).
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
If we have no nontrivial notify vfunc, and no signal
handlers for notify, we don't need to maintain the
notify queue. No need to notify if nobody's listening.
Check whether an object has a nontrivial notify vfunc
and avoid creating and updating the notify queue if
it doesn't. We know that there can be no notify signal
handlers at this point. No need to notify if nobody's
listening.
We currently keep a flag for whether an object has
ever had any signal handlers. But even if it had signal
handlers, it may not have any notify handlers. Keep that
information separately, so we can speed up property setting.
According to the commit that introduced these
calls (4b334ef8f1), we are checking
the refcount here to avoid calling g_object_ref
when the refcount is 0, in the rare case that
notification would be triggered during finalize.
But we are now freezing notifications during
finalize, and after recent changes, we no longer call
g_object_ref for notification while a freeze is
in place.
We only need to take a ref on the object when
we call out to external code (ie around
->dispatch_properties_changed). If we avoid
the signal emission, we can avoid the ref/unref
too. This is not currently happening, but
might in the future.
A small reorg that reduces the code and matches
what we do for object_get_property.
Note that as a consequence of this change, we now
check the deprecated flag on the redirected property,
not on the original when setting properties. This
matches what we were already doing for getting
properties.
The code that emits property deprecation warnings
rarely runs, and doesn't need to be inlined
everywhere. It is enough to inline the check for
the deprecation flag.
It is safe not to copy arguments here,
because we are not emitting any signals
before we are done setting the values
as properties.
This matches what we do for g_object_new now.
We can safely use the values without copying here.
This is safe because we are not emitting any
signals before we are done setting the values
as properties.
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.
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 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.
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>
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
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
