It was always passed the same value by all users of the macro.
This introduces no functional changes.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Rather than atomically querying the flags, and then atomically reffing
the `GClosure`, do the atomic ref and return the new flags value as a
side-effect. This eliminates the need for an additional atomic read, and
eliminates a race window between the two accesses.
It does mean we need a new internal version of `g_closure_ref()` which
returns the new `GClosureFlags` though.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Remove the last few non-atomic reads of `GClosure.ref_count`. See
previous commits for an explanation of why this is important.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Currently, `GClosure` does atomic writes to the flags in its initial
bitfield, but it never does atomic reads from them. This is not safe —
even if the memory read for an int is atomic, the compiler might
duplicate or rearrange a non-atomic read and give an unexpected result.
Using an atomic fetch inserts the necessary compiler and hardware
barriers to ensure a single result is fetched.
(See !4575 of an example of where this kind of bug has caused
misbehaviour.)
So, introduce an atomic read helper for the `GClosure` bitfield. Rather
than reading a single member of the bitfield, it returns the entire
bitfield, as several `GClosure` methods need access to multiple members
of the bitfield, and atomically fetching them all separately would not
be atomic overall.
Fix various `GClosure` methods to use the new atomic read function.
There are more parts of the code still to fix — these were just the
straightforward ones.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Depending on luck, g_closure_ref may access closure->vint and observe
different values between reads. This manifests as a test failure in
signals-refcount{2,4}, properties-refcount1, and closure-refcount depending
on timing and re-runs.
Jakub Jelinek analysed this on GCC bug PR119607 after I'd reported it
over there as a possible GCC regression.
The critical part being g_closure_ref -> ATOMIC_INC_ASSIGN -> ATOMIC_CHANGE_FIELD
where closure->vint gets re-read repeatedly, both outside and inside the retry
loop. To fix that:
1. Atomically fetch it the first time;
2. Use the cached read, not a fresh read, of vint in the loop;
3. Use g_atomic_int_compare_and_exchange_full in the loop so we get a freshly
cached vint if it changed in another thread.
Bug: https://gcc.gnu.org/PR119607
Fixes: 834ddd19 ('turned all modifications to the first 32 integer bits in a closure into')
Co-authored-by: Jakub Jelinek <jakub@redhat.com>
This just makes it a bit clearer that they’re atomic/for thread safety,
and not just NIHed bit operations with shouty names.
This introduces no functional changes.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
This avoids the need to ref/unref the closure while invalidating it in
the `closure->ref_count == 1` path in `g_closure_unref()`.
scan-build gets very confused about the ref count here, and ends up
assuming it’s possible for the `g_closure_unref()` call in
`g_closure_invalidate()` to finalise the closure when the latter is
called from `g_closure_unref()`. There was an existing assertion in
`g_closure_invalidate()` which hinted that this wasn’t possible, but
scan-build doesn’t seem to be able to propagate assumptions about
refcounts between function contexts.
So, introduce an internal variant of `g_closure_invalidate()` which can
skip modifying the closure’s refcount. It’s safe to invalidate the
closure without adding a ref when doing so from `g_closure_unref()` with
`closure->ref_count == 1` because at that point `g_closure_unref()`
holds the only remaining ref to the closure. So none of the invalidation
callbacks are allowed to unref it further.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Helps: #1767
On CHERI-enabled systems we use uintptr_t as the underlying storage for
GType and therefore casting to gsize strips the upper bits from a pointer.
Fix this by casting via uintptr_t instead and introduce a new set of
macros to convert between GType and pointers.
They return floating references, so that should be reflected in the
introspection annotations.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
All of these warnings indicate programmer error, so critical is most
appropriate here.
Exceptions: deprecation warnings are just warnings. Also, warnings that
are worded with uncertainty can remain warnings rather than criticals.
These have all been added manually, as I’ve finished all the files which
I can automatically detect.
All the license headers in this commit are for LGPL-2.1-or-later, and
all have been double-checked against the license paragraph in the file
header.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1415
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
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
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 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>
This reverts commits:
5899c61ed2b4be3f02d0382d6fb0d1fc1bb7bc98
e994d4535270b233c4ed5c62e0055fe20c9ab1c6
eb20dec144765d255928fb3e0df960b09af5904d
ebec0dd359eb3a3dc5dbf8ac533a7d89cfc72267
which wer accidentally pushed to master instead of a branch
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.
valgrind.h is a verbatim copy taken from Valgrind project. Previously
that file had local changes that got dropped by last update. To avoid
regressing again, do not edit valgrind.h anymore and instead add a
gvalgrind.h wrapper that gets included instead.
This fix 2 errors:
- uintptr_t is not defined when including valgrind.h on mingw.
- MSVC compiler is not supported on amd64-Win64 platform.
The critical omission from the GClosure documentation is that you need
to call g_closure_set_marshal() when implementing a custom GClosure.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Reviewed-by: nobody
Putting a <!-- --> in plural<!-- -->s was an old hack used to fix
linking the symbol with gtk-doc when gtk-doc didn’t know about plural
forms. gtk-doc does now know about plural forms, so the hack can be
removed.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
They return floating references. The convention established by GVariant
is to annotate these as (transfer none) so that the caller does a
ref+sink on them, rather than just a ref.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
https://bugzilla.gnome.org/show_bug.cgi?id=677233
If we have an input parameter (or return value) we need to use (nullable).
However, if it is an (inout) or (out) parameter, (optional) is sufficient.
It looks like (nullable) could be used for everything according to the
Annotation documentation, but (optional) is more specific.
Add various (nullable) and (optional) annotations which were missing
from a variety of functions. Also port a couple of existing (allow-none)
annotations in the same files to use (nullable) and (optional) as
appropriate instead.
Secondly, add various (not nullable) annotations as needed by the new
default in gobject-introspection of marking gpointers as (nullable). See
https://bugzilla.gnome.org/show_bug.cgi?id=729660.
This includes adding some stub documentation comments for the
assertion macro error functions, which weren’t previously documented.
The new comments are purely to allow for annotations, and hence are
marked as (skip) to prevent the symbols appearing in the GIR file.
https://bugzilla.gnome.org/show_bug.cgi?id=719966
GClosure has been in the "allocate area before the pointer" game since
before we did this with GTypeInstance. At the time that this was done
for GClosure, we didn't have valgrind.h in GLib.
Now that we do, we should add similar valgrind hints as the ones we did
for GTypeInstance. This substantially reduces reports of "possibly
lost" on pretty much any program that makes use of signals.
https://bugzilla.gnome.org/show_bug.cgi?id=739850
Since we are no longer using sgml mode, using /* */ to
escape block comments inside examples does not work anymore.
Switch to using line comments with //
