In preparation for deprecating the old APIs. This shouldn’t functionally
affect the tests.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1931
These are alternatives to the existing `time_t`-based APIs, which will
soon be deprecated due to `time_t` only being Y2038-safe on 64-bit
systems.
The new APIs take a GDateTime instead.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1931
When targeting mingw on architectures other than x86, the earlier cases
don't apply, and the final fallback, raise(SIGTRAP) isn't usable there.
GCC and Clang both support __builtin_trap(), so in case we have no
other alternatives, and are on windows (where raise() isn't available),
we can resort to this.
When timeout grater than 0 in g_poll function, the WaitForMultipleObjects
call will wait for all the threads to return, but when only one thread
got an event the others will sleep until the timeout elapses, and causes
a stall. Triggering the stop event in g_poll in this case is useless as
it is triggered when all the threads where already signaled or timed-out.
Closes: https://gitlab.gnome.org/GNOME/glib/issues/2107
The g_once() function exists to call a callback function exactly once,
and to block multiple contending threads on its completion, then to
return its return value to all of them (so they all see the same value).
The full implementation of g_once() (in g_once_impl()) uses a mutex and
condition variable to achieve this, and is needed in the contended case,
where multiple threads need to be blocked on completion of the callback.
However, most of the times that g_once() is called, the callback will
already have been called, and it just needs to establish that it has
been called and to return the stored return value.
Previously, a fast path was used if we knew that memory barriers were
not needed on the current architecture to safely access two dependent
global variables in the presence of multi-threaded access. This is true
of all sequentially consistent architectures.
Checking whether we could use this fast path (if
`G_ATOMIC_OP_MEMORY_BARRIER_NEEDED` was *not* defined) was a bit of a
pain, though, as it required GLib to know the memory consistency model
of every architecture. This kind of knowledge is traditionally a
compiler’s domain.
So, simplify the fast path by using the compiler-provided atomic
intrinsics, and acquire-release memory consistency semantics, if they
are available. If they’re not available, fall back to always locking as
before.
We definitely need to use `__ATOMIC_ACQUIRE` in the macro implementation
of g_once(). We don’t actually need to make the `__ATOMIC_RELEASE`
changes in `gthread.c` though, since locking and unlocking a mutex
guarantees to insert a full compiler and hardware memory barrier
(enforcing sequential consistency). So the `__ATOMIC_RELEASE` changes
are only in there to make it obvious what stores are logically meant to
match up with the `__ATOMIC_ACQUIRE` loads in `gthread.h`.
Notably, only the second store (and the first load) has to be atomic.
i.e. When storing `once->retval` and `once->status`, the first store is
normal and the second is atomic. This is because the writes have a
happens-before relationship, and all (atomic or non-atomic) writes
which happen-before an atomic store/release are visible in the thread
doing an atomic load/acquire on the same atomic variable, once that load
is complete.
References:
* https://preshing.com/20120913/acquire-and-release-semantics/
* https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/_005f_005fatomic-Builtins.html
* https://gcc.gnu.org/wiki/Atomic/GCCMM/AtomicSync
* https://en.cppreference.com/w/cpp/atomic/memory_order#Release-Acquire_ordering
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1323
There were multi-threaded tests for g_once_init_{enter,leave}(), but not
for g_once(). Add one which tests multi-threaded contention for entering
and retrieving the value of the `GOnce`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1323
It’s not expected that bindings will use `GThread` over their own
threading APIs (in fact that would generally be a bad idea, since
threads benefit from being integrated into language control flow
structures), but it can’t hurt to have the annotations right for
documentation purposes if nothing else.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #602
Unify the creation of GPtrArray.
Maybe we will add yet another constructor for creating %NULL terminated
arrays. Unify the constructors by adding an internal helper method.
The alternative instead of adding a ptr_array_new() helper, would be to
let everybody call g_ptr_array_full(). For no strong reasons, choose
this approach because the compiler is more eager to inline the static
helper as it would inlining g_ptr_array_full().
This reverts commit c0146be3a4.
The revert was originally added because the original change broke
gnome-build-meta. Now that the problem has been diagnosed, the original
commit can be fixed — see the commit which follows this one.
See: !1487
The public functions exposed as static inlines currently don't have
annotations to describe when they were introduced. This means that
compiling this file:
#include <glib.h>
void foo (void)
{
g_rec_mutex_locker_new (NULL);
}
with:
gcc -c test.c \
-I/tmp/glib/include/glib-2.0 \
-I/tmp/glib/lib/x86_64-linux-gnu/glib-2.0/include \
-Werror \
-DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_28 \
-DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_28
will not produce any error message, despite using
`g_rec_mutex_locker_new`, a function that was introduced after 2.28.
This patch adds some annotations to all the publicly exposed static
inline functions I could find.
I could not use the existing G_AVAILABLE* macros, because they may
expand to `extern`. This would then clash with the `static` keyword and
produce:
../glib/gthread.h:397:1: error: multiple storage classes in declaration specifiers
397 | static inline GRecMutexLocker *
| ^~~~~~
So I opted for adding a new set of macros,
GLIB_AVAILABLE_STATIC_INLINE_IN_2_XY.
With this patch applied, the example from above produces the expected
warning:
test.c: In function ‘foo’:
test.c:5:3: error: ‘g_rec_mutex_locker_new’ is deprecated: Not available before 2.60 [-Werror=deprecated-declarations]
5 | g_rec_mutex_locker_new (NULL);
| ^~~~~~~~~~~~~~~~~~~~~~
In file included from /tmp/glib/include/glib-2.0/glib/gasyncqueue.h:32,
from /tmp/glib/include/glib-2.0/glib.h:32,
from test.c:1:
/tmp/glib/include/glib-2.0/glib/gthread.h:398:1: note: declared here
398 | g_rec_mutex_locker_new (GRecMutex *rec_mutex)
| ^~~~~~~~~~~~~~~~~~~~~~
This seems to have existed since the code was written and I can’t see
a need for it.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #2106
g_ptr_array_extend_and_steal() leaves the GPtrArray in an invalid state,
so if you would try to append another pointer, it leads to a crash.
Also adjust the test case so that it would result in the crash (without
the fix).
Fixes: 0675703af0 ('Adding g_ptr_array_extend_and_steal() function to glib/garray.c')
With a trivial file that just includes glib.h:
#include <glib.h>
Compiled with:
gcc -c test.c \
-I /tmp/glib/include/glib-2.0/ \
-I /tmp/glib/lib/x86_64-linux-gnu/glib-2.0/include \
-DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_28 \
-DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_28 \
-fmax-errors=1 \
-Werror
We get:
In file included from /tmp/glib/include/glib-2.0/glib/gasyncqueue.h:32,
from /tmp/glib/include/glib-2.0/glib.h:32,
from test.c:1:
/tmp/glib/include/glib-2.0/glib/gthread.h: In function ‘g_rec_mutex_locker_new’:
/tmp/glib/include/glib-2.0/glib/gthread.h:396:3: error: ‘g_rec_mutex_lock’ is deprecated: Not available before 2.32 [-Werror=deprecated-declarations]
396 | g_rec_mutex_lock (rec_mutex);
| ^~~~~~~~~~~~~~~~
/tmp/glib/include/glib-2.0/glib/gthread.h:196:17: note: declared here
196 | void g_rec_mutex_lock (GRecMutex *rec_mutex);
| ^~~~~~~~~~~~~~~~
compilation terminated due to -fmax-errors=1.
The problem is that the code in the static inline functions uses
g_rec_mutex_lock, introduced after 2.28. This code is compiled
regardless of if it's actually used or not.
Suppress the warning by using G_GNUC_BEGIN_IGNORE_DEPRECATIONS /
G_GNUC_END_IGNORE_DEPRECATIONS. There are precedents for doing that,
for example g_main_context_pusher_new in gmain.h.
Tested by building with all variations of GLIB_VERSION_MIN_REQUIRED /
GLIB_VERSION_MAX_ALLOWED:
for i in $(seq 26 2 64); do
gcc -c test.c \
-I/tmp/glib/include/glib-2.0 \
-I/tmp/glib/lib/x86_64-linux-gnu/glib-2.0/include \
-DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_$i \
-DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_$i \
-fmax-errors=1 \
-Werror
done
Fixes: #2094
Otherwise the code ends up calling `gettext ("")`, which returns the
current translation’s header. The caller should really have provided a
NULL, parameter string, but the empty string is clear enough.
See
https://gitlab.freedesktop.org/accountsservice/accountsservice/-/merge_requests/56.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
When g_variant_get_child() is called on a variant which has not been
serialized, it serializes it which includes a call to
g_variant_release_children() and therefore means that any children
previously retrieved from the variant are no longer valid (unless
another reference is held on them) and consequently values borrowed from
those children are no longer safe to access. Add a note to the
g_variant_get_child_value() documentation to explain this.
Alternatively, we could say that after the child is freed, values
borrowed from it are no longer valid. But we already have an
implementation which hasn't changed in years which lets them stay valid
if the variant was serialized before the first
g_variant_get_child_value() call.
Here's a demonstration of the memory error:
static const char *get_first_child (GVariant *v) {
g_autoptr(GVariant) child_v = g_variant_get_child_value (v, 0);
return g_variant_get_string (child_v, NULL);
}
int main(int argc, char **argv) {
g_autoptr(GVariant) v = g_variant_new("(@ss)", g_variant_new_string ("hello"), "world");
const char *child1 = get_first_child (v);
const char *child2;
g_variant_get_child (v, 1, "&s", &child2);
printf ("%s\n", child1); // this is a memory error
return 0;
}
The local change from af0e0cb995 in glib ended upstreamed
as 7359c5fd9f312cddd62146896558d8c9bd2bd4cf in valgrind, with
a few minor adjustments requested from there.
Sync this local modification to what ended up upstreamed, to avoid
any doubt regarding it for future syncs of the whole header.
The gnulib math code uses __builtin_isnanf and __builtin_isnanl
within the __GNUC__ >= 4 ifdef, and clang doesn't provide those
builtins, only the one without a suffix. Make the meson check
match the code it controls, using the exactly right builtins.
Set REPLACE_ISNAN to 1 if either of the have_isnan* functions failed,
this matches how gnulib's m4 routines does it (in gnulib/m4/isnan.m4).
This fixes the isnan functions in the gnulib math header replacement
work on Clang.
Many locales have no concept of AM/PM notation, and it’s confusing to
them. It’s an Anglo-centric concept which doesn’t belong in the API at
this level — instead, programs should use more generic format specifiers
which leave the details of how to format a date/time to the locale.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #2082
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').
"\t" is not escaped by g_markup_escape_text(), as per its documentation:
"Note that this function doesn't protect whitespace and line endings
from being processed according to the XML rules for normalization of
line endings and attribute values."
The relevant portion of the XML specification
https://www.w3.org/TR/xml/#AVNormalize
"For a character reference, append the referenced character to the
normalized value."
"For a white space character (#x20, #xD, #xA, #x9), append a space
character (#x20) to the normalized value."
So the unescape code in GMarkup does the right thing as can be verified
by the added valid-17.* data files for the markup-parse unit test.
(Note that the valid-13.* data files already tested a plain tab
character in an attribute value, among other white space characters).
Note that the libxml2's xmlSetProp() function escapes "\t" into the
character reference "	".
See https://gitlab.gnome.org/GNOME/glib/-/issues/2080
Update our copy of valgrind.h from the Valgrind 3.15 release tarball,
and then re-apply our downstream change af0e0cb995. No other
changes made.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
malloc() was given too small value (size of pointer,
rather than struct it points to), and subsequent call
getpwnam_r() wrote past the end of allocated block - easily
seen with valgrind.
Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
Don't assume that __MINGW32__ implies x86; Windows runs on ARM/ARM64
as well, and there are mingw toolchains that target those architectures.
This mirrors how the MSVC part of the same expressions are written,
as (defined(_WIN32) && defined(_M_IX86)) and
(defined(_WIN64) && defined(_M_X64)) - not relying on _WIN32/_WIN64
or __MINGW32__/__MINGW64__ alone to indicate architecture.
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.
Using commands:
```
glib/gen-unicode-tables.pl -both 13.0.0 path/to/UCD
tests/gen-casefold-txt.py 13.0.0 path/to/UCD/CaseFolding.txt \
> tests/casefold.txt
tests/gen-casemap-txt.py 13.0.0 path/to/UCD/UnicodeData.txt \
path/to/UCD/SpecialCasing.txt > tests/casemap.txt
```
Using UCD release https://www.unicode.org/Public/zipped/13.0.0/UCD.zip
With some manual additions to `GUnicodeScript` for the 4 new scripts
added in 13.0, using the first assigned character in each block in
`glib/tests/unicode.c`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
The test checks `g_str_match_string()` function, which performs matches
based on user's locale. For this reason, some tests may fail, e.g., see
issue #868.
Now we explicitly set locale for each test, with C locale as a fallback
when the locale is not available.
clang complains about this in the form of
<source>:6:9: warning: result of comparison against a string literal is
unspecified (use an explicit string comparison function instead)
if (f == (void *)"a") {
^ ~~~~~~~~~~~
Use variables for the strings instead, which should have the same
address.
It seems a bit unhelpful to list every single `g_assert_*()` macro, to
rephrase the documentation to use globs instead.
Add a missing word below.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
This is for use in testing POSIX-style functions like `rmdir()`, which
return an integer < 0 on failure, and return their error information in
`errno`.
The new macro prints `errno` and `g_strerror (errno)` on failure.
Includes a unit test.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
`mem-overflow` test disables GCC warning `alloc-size-larger-than` via
diagnostic pragma, but it's still emitted in the linkage stage when
LTO is enabled.
This changes explicitly set `link_args` for the test to disable the
warning.
Some compilers have __GNUC__ defined as a value less than 6, but do
support implicit-fallthrough via __attribute__((fallthrough)). Define
G_GNUC_FALLTHROUGH for those that support __has_attribute.
Spotted by Mohammed Sadiq. `g_array_copy()` was doing a `memcpy()` of
the data from the old array to the new one, based on the reserved
elements in the old array (`array->alloc`). However, the new array was
allocated based on the *assigned* elements in the old array
(`array->len`).
So if the old array had fewer assigned elements than allocated elements,
`memcpy()` would fall off the end of the newly allocated data block.
This was particularly obvious when the old array had no assigned
elements, as the new array’s data pointer would be `NULL`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #2049
Most of these scripts can probably just be deleted (see issue #2045),
but for now it was easier to just mechanically fix the shellcheck
warnings in them, rather than think about whether we actually needed the
script.
Fixes done using shellcheck 0.7.0 with default options. I haven’t tested
any of the changes.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Move the separate function inline using g_once_init_{enter,leave}(),
rather than g_once().
This marginally improves performance, taking 0.39s to create 10000000
UTC timezones, rather than 0.43s previously. (Who cares?)
Follow-up to !1105.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
It’s quite surprising that this wasn’t documented already. Hash tables
are unordered, and any recognisable iteration ordering is not guaranteed
and might change in future releases.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Instead only do a g_critical(). This is something that has to be fixed
one way or another, but a g_critical() is less disruptive and makes sure
that code that worked in previous GLib versions still works as bad as
before.
Fixes https://gitlab.gnome.org/GNOME/glib/issues/2039
Some CI platforms invoke these tests with euid != 0 but with
capabilities. Detect whether we have Linux CAP_DAC_OVERRIDE or other
OSs' equivalents, and skip tests that rely on DAC permissions being
denied if we do have that privilege.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Fixes: https://gitlab.gnome.org/GNOME/glib/issues/2027
Fixes: https://gitlab.gnome.org/GNOME/glib/issues/2028
Some CI platforms invoke tests as euid != 0, but with capabilities that
include CAP_SYS_RESOURCE and/or CAP_SYS_ADMIN. If we detect this,
we can't test what happens if our RLIMIT_NPROC is too low to create a
thread, because RLIMIT_NPROC is bypassed in these cases.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Fixes: https://gitlab.gnome.org/GNOME/glib/issues/2029
This does not have any behaviour changes but is cleaner. The mutex is
only unlocked now after all operations on the context are done and right
before freeing the mutex and the context itself.
Instead of destroying sources directly while freeing the context, and
potentially freeing them if this was the last reference to them, collect
new references of all sources in a separate list before and at the same
time invalidate their context so that they can't access it anymore. Only
once all sources have their context invalidated, destroy them while
still keeping a reference to them. Once all sources are destroyed we get
rid of the additional references and free them if nothing else keeps a
reference to them anymore.
This fixes a regression introduced by 26056558be in 2012.
The previous code that invalidated the context of each source and then
destroyed it before going to the next source without keeping an
additional reference caused memory leaks or memory corruption depending
on the order of the sources in the sources lists.
If a source was destroyed it might happen that this was the last
reference to this source, and it would then be freed. This would cause
the finalize function to be called, which might destroy and unref
another source and potentially free it. This other source would then
either
- go through the normal free logic and change the intern linked list
between the sources, while other sources that are unreffed as part of
the main context freeing would not. As such the list would be in an
inconsistent state and we might dereference freed memory.
- go through the normal destroy and free logic but because the context
pointer was already invalidated it would simply mark the source as
destroyed without actually removing it from the context. This would
then cause a memory leak because the reference owned by the context is
not freed.
Fixes https://github.com/gtk-rs/glib/issues/583 while still keeping
https://bugzilla.gnome.org/show_bug.cgi?id=661767 fixes.
We first have to ref the next source and then unref the previous one.
This might be the last reference to the previous source, and freeing the
previous source might unref and free the next one which would then leave
use with a dangling pointer here.
Fixes https://gitlab.gnome.org/GNOME/glib/issues/2031
It was used for running tests when we built with autotools, but is no
longer used in the Meson build system. If we need something similar in
future, it should be done by adding internal API to override the
directory on a per-call basis, rather than loading a path from a shared
global table every time.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1919
There were a couple of custom paths which could end up being relative,
rather than absolute, due to not properly prefixing them with
`get_option('prefix')`.
The use of `join_paths()` here correctly drops all path components
before the final absolute path in the list of arguments. So if someone
configures GLib with an absolute path for `gio_module_dir`, that will be
used unprefixed; but if someone configures with a relative path, it will
be prefixed by `get_option('prefix)`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1919
Even if the key already exists in the table, `g_hash_table_add()` will
call the hash table’s key free func on the old key and will then replace
the old key with the newly-passed-in key. So `key` is always `(transfer
full)`.
In particular, `key` should never need to be freed by the caller if
`g_hash_table_add()` returns `FALSE`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Since we (optionally) require nanosecond precision for this
(utimes() is used on *nix), use SetFileTime(), which nominally
has 100ns granularity (actual filesystem might be coarser), instead of
g_utime (), which only has 1-second granularity.
Expand our private statbuf structure with st_mtim, st_atim and st_ctim
fields, which are structs that contain tv_sec and tv_nsec fields,
representing a timestamp with 1-second precision (same value as st_mtime, st_atime
and st_ctime) and a fraction of a second (in nanoseconds) that adds nanosecond
precision to the timestamp.
Because FILEETIME only has 100ns precision, this won't be very precise,
but it's better than nothing.
The private _g_win32_filetime_to_unix_time() function is modified
to also return the nanoseconds-remainder along with the seconds timestamp.
The timestamp struct that we're using is named gtimespec to ensure that
it doesn't clash with any existing timespec structs (MinGW-w64 has one,
MSVC doesn't).
794c1a30bc "macro wrappers for
g_once_init_enter/leave" added this line (whose intent is unclear to me).
<http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1152r4.html>
"Deprecating volatile" (scheduled for inclusion in C++20) will make the
assignment expression
*(location) = (result)
deprecated when the LHS is of (non-class) volatile type, which is the case when
g_once_init_leave is expanded as part of e.g. G_DEFINE_TYPE_WITH_CODE (in
gobject/gtype.h), where location is a pointer to some
static volatile gsize g_define_type_id__volatile = 0;
Recent Clang trunk emits -Wdeprecated-volatile for it under -std=c++2a since
<https://github.com/llvm/llvm-project/commit/
4a6861a7e5b59be24a09b8b9782255d028e7aade> "[c++20] P1152R4: warn on any
simple-assignment to a volatile lvalue".
The fix is to make the assignment expression a discared-value expression by
casting it to void (which in turn requires casting the second branch of the
surrounding conditional expression to void, too; not sure what the top-level
cast to void was intended for, and whether it would still be needed under
certain circumstances).
Previously we would only ever run the initialization code once, but part
of it only if a non-exclusive pool was created. This caused the shared
state to be inconsistent if the first pool to be created was exclusive
and the second non-exclusive.
Fixes https://gitlab.gnome.org/GNOME/glib/issues/2012
g_setenv() and g_unsetenv() can never be thread-safe, so emit a message if
they are used after any threads have been spawned.
This can’t catch interactions between setenv() and g_thread_new(), or
between g_setenv() and pthread_create(), but it’ll catch most
misbehaviour in GLib-centric code.
Currently, the message is a `g_debug()` call. Eventually, I’d like to
upgrade it to a `g_warning()`, but there are a number of GLib tests
which call g_setenv() after threads have been created, and they need to
be fixed first. Emitting a `g_debug()` message gives people an
opportunity to start fixing their code.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #715
This will be used in a following commit to warn if setenv() is used
after another thread has been created.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #715
It’s now used unconditionally for `shared_thread_scheduler_settings` in
`gthreadpool.c`, so it actually needs to have a storage definition.
Fixes a build failure on FreeBSD.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
On Linux the sched_getattr syscall might be available at compile-time
but not actually work at runtime (e.g. because an older kernel is
running or valgrind is used). Instead of killing the process, return
FALSE and handle this gracefully at runtime with some fallback code.
Fixes https://gitlab.gnome.org/GNOME/glib/issues/2007
By default (on POSIX) we would be inheriting thread priorities from the
thread that pushed a new task on non-exclusive thread pools and causes a
new thread to be created. This can cause any non-exclusive thread pool
to accidentally contain threads of different priorities, or e.g. threads
with real-time priority.
To prevent this, custom handling for setting the scheduler settings for
Linux and Windows is added and as a fallback for other platforms a new
thread is added that is responsible for spawning threads for
non-exclusive thread pools.
Fixes https://gitlab.gnome.org/GNOME/glib/issues/1834
This means that GLib will generate appropriate deprecation warnings if
`GLIB_VERSION_MAX_ALLOWED` has been set to target a GLib version older
than 2.58.
The timezone(3) man page on Fedora 31 describes the start/end
field in the POSIX TZ format as follows:
[quote]
The start field specifies when daylight saving time goes
into effect and the end field specifies when the change is
made back to standard time. These fields may have the fol‐
lowing formats:
Jn This specifies the Julian day with n between 1 and
365. Leap days are not counted. In this format,
February 29 can't be represented; February 28 is day
59, and March 1 is always day 60.
n This specifies the zero-based Julian day with n
between 0 and 365. February 29 is counted in leap
years.
Mm.w.d This specifies day d (0 <= d <= 6) of week w (1 <= w
<= 5) of month m (1 <= m <= 12). Week 1 is the
first week in which day d occurs and week 5 is the
last week in which day d occurs. Day 0 is a Sunday.
[/quote]
The GTimeZone code does not correctly parse the 'n' syntax,
treating it as having the range 1-365, the same as the 'Jn'
syntax. This is semantically broken as it makes it impossible
to represent the 366th day, which is the purpose of the 'n'
syntax.
There is a code comment saying this was done because the Linux
semantics are different from zOS and BSD. This is not correct,
as GLibC does indeed use the same 0-365 range as other operating
systems. It is believed that the original author was mislead by
a bug in old versions of the Linux libc timezone(3) man pages
which was fixed in
commit 5a554f8e525faa98354c1b95bfe4aca7125a3657
Author: Peter Schiffer <pschiffe@redhat.com>
Date: Sat Mar 24 16:08:10 2012 +1300
tzset.3: Correct description for Julian 'n' date format
The Julian 'n' date format counts atrting from 0, not 1.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Fixes: #1999
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The callers of parse_tz_boundary inverted the value passed
for the ignore_leap parameter. Fortunately the method impl
also had an inverted test cancelling out the first bug.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The implementation has always wrapped at 76 characters, rather than 72,
ever since it was introduced in commit 5cf8f1d4a8 in 2006. At this
stage, it’s probably best to fix the documentation rather than the
implementation.
The likely bug in the implementation is the comparison
```
(++already) >= 19
```
19 × 4 = 76, so it seems like an off-by-one error in the comparison.
What was actually wanted was 18 × 4 = 72.
Thanks to Simon McVittie for the investigation and diagnosis.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1997
Similar to 3837b83f, glibc memcpy is declared with the first two
arguments annotated as non-null via an attribute, which results in the
undefined behaviour sanitizer considering it to be UB to pass a null
pointer there (even if we are copying no bytes, and hence not actually
dereferencing the pointer).
Signed-off-by: Simon McVittie <smcv@collabora.com>
g_atomic_pointer_compare_and_exchange() should work with const pointers.
Add a test for that.
It seems clang 9.0.0-2.fc32 does not like this:
../glib/tests/atomic.c:93:9: warning: incompatible pointer types passing 'typeof ((((void *)0))) *' (aka 'void **') to parameter of type 'const char **' [-Wincompatible-pointer-types]
res = g_atomic_pointer_compare_and_exchange (&vp_str, NULL, str);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../glib/gatomic.h:192:44: note: expanded from macro 'g_atomic_pointer_compare_and_exchange'
__atomic_compare_exchange_n ((atomic), &gapcae_oldval, (newval), FALSE, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ? TRUE : FALSE; \
^~~~~~~~~~~~~~
../glib/tests/atomic.c:96:9: warning: incompatible pointer types passing 'typeof ((((void *)0))) *' (aka 'void **') to parameter of type 'const char **' [-Wincompatible-pointer-types]
res = g_atomic_pointer_compare_and_exchange (&vp_str_vol, NULL, str);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../glib/gatomic.h:192:44: note: expanded from macro 'g_atomic_pointer_compare_and_exchange'
__atomic_compare_exchange_n ((atomic), &gapcae_oldval, (newval), FALSE, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ? TRUE : FALSE; \
^~~~~~~~~~~~~~
Note that this clang version already issues various compiler warnings for
this test. This merely adds another case to check.
Eventually g_atomic_pointer_compare_and_exchange() should be fixed to
avoid compiler warnings.
Actually there is a problem. When you try to use g_atomic_pointer_compare_and_exchange()
with const pointers, it is also not working, because the implementation
as a function expects "void *" arguments. As the test also shows. As such,
it's probably not portable to use g_atomic_pointer_compare_and_exchange()
with const pointers at all. However, the macro implementation is (with the right
compiler) fine with that, so it's an easy "mistake" to make.
Even if g_variant_get_va(), which we eventually call, checks on the
validity of the value argument, check it early to avoid surprises, such
as this intermittent FreeBSD test failure:
(/var/tmp/gitlab_runner/builds/3fe11159/0/GNOME/glib/_build/gio/tests/gdbus-connection:65788): GLib-CRITICAL **: 15:13:25.670: g_variant_get_va: assertion 'value != NULL' failed
Especially check for a valid reference count. This is possible now in
all cases because of the addition of the dispose function and makes
usage of already finalized/finalizing GSources more obvious than the
use-after-free that would otherwise happen.
This allows GSource implementors to safely clear any other references to
the GSource while the GSource is still valid, unlike when doing the same
from the finalize function.
After the dispose function has run, it is valid for the reference count
of the GSource to be > 0 again to allow the case where another thread in
the mean-time got access to the GSource reference before the dispose
function was called.
This allows fixing a thread-safety issue in the GCancellable, GstBus and
various other GSource implementations.
When compiling a program using glib with -Wzero-as-null-pointer-constant
warnings enabled, the compiler warns about this type check in the
g_once_init_enter macro. Fix by replacing "0" with "NULL".
This is a convenience wrapper around getpwnam_r() which handles all the
memory allocation faff.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1687
Although not quite as often-occurring, this should help with constructs
like this:
if (list)
{
g_list_free_full (list, foo);
list = NULL;
}
Closes https://gitlab.gnome.org/GNOME/glib/issues/1943
In C, the proper type for a heap allocate structure is size_t/gsize.
That means, no valid (heap allocated) pointer will ever contain more
bytes than size_t can represent.
Hence, this integer type should also be used when operating on
data like a strv array. Adjust some internal uses to use gsize
instead of gint/guint.
Note that g_strv_length() returns a value of type guint. So this
API cannot be used on string arrays longer of arbitrary size. But
that is not fixable.
This reverts commit fd3ed5e31b.
C11-style atomics have been fixed (on FreeBSD and other platforms) in
the previous commit, “gatomic: Check argument width in
g_atomic_pointer_compare_and_exchange()”.
See !1229 and #1940.
Check that the new value is actually pointer-width, rather than (for
example) `sizeof (int)` which could happen if someone used `0` rather
than `NULL`.
Changes suggested by Simon McVittie.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1940
Don’t pass integers; it’s not type-safe. The macro version of
`g_atomic_pointer_compare_and_exchange()` used to erroneously accept
integers, but they would have the wrong width on some platforms.
Changes originally investigated and suggested by Ting-Wei Lan.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1940
They’re causing the CI to fail. While someone familiar with FreeBSD
investigates the failure, it’s easiest to disable all C11-style atomics
than add more preprocessor checks to only disable the atomics added in
!1123.
If nobody can fix the new C11-style atomics before the 2.64.0 release,
this commit should be reverted and a more comprehensive set of preprocessor
checks put in place to essentially revert !1123 for BSD only.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1940
In glib/gutf8.c there was an UB in function g_utf8_find_prev_char when
p == str. In this case we substract one from p and now p points to a
location outside of the boundary of str. It's a UB by the standard.
Since this function are meant to be fast, we don't check the boundary
conditions.
Fix glib/tests/utf8-pointer test. It failed due to the UB described
above and aggressive optimisation when -O2 and LTO are enabled. Some
compilers (e.g. GCC with major version >= 8) create an optimised version
of g_utf8_find_prev_char with the first argument fixed and stored
somewhere else (with a different pointer). It can be solved with either
marking str as volatile or creating a copy of str in memory. We choose
the second approach since it's more explicit solution.
Add additional checks to glib/tests/utf8-pointer test.
Closes#1917
Commit 7678b107 seems to have left the GHashTable pretty printer with an
off-by-one error, skipping the first key it encounters and printing an
extra garbage key/value pair instead. This fixes that by moving an
increment to the end of a loop rather than the beginning.
This ensures that when running many instances of the test in parallel,
they don’t collide in the same current directory, and hence spuriously
fail. This can happen when writing `out.xbel`, for example.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1930
In general, we should aim to always check a `GError` before checking a
boolean, since the error message from the `GError` gives us a lot more
information about failure, which helps with debugging.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
The time handling was assuming that the test would complete in the same
second as it started, which was not always true.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1930
`g_assert_*()` gives more useful messages on failure, and isn’t compiled
out by `G_DISABLE_ASSERT`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Similar to 3837b83f, glibc memcmp is declared with the first two
arguments annotated as non-null via an attribute, which results in the
undefined behaviour sanitizer considering it to be UB to pass a null
pointer there (even if we are comparing 0 bytes, and hence not actually
dereferencing the pointer).
This shows up in /gvariant/serialiser/children when run with the
undefined behaviour sanitizer.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Similar to 3837b83f, glibc memcmp is declared with the first two
arguments annotated as non-null via an attribute, which results in the
undefined behaviour sanitizer considering it to be UB to pass a null
pointer there (even if we are comparing 0 bytes, and hence not actually
dereferencing the pointer).
This shows up in /gvariant/serialiser/children when run with the
undefined behaviour sanitizer.
Signed-off-by: Simon McVittie <smcv@collabora.com>
kdeinit5 overwrites argv, which in turn results in /proc/self/cmdline
being overwritten. It seems that this is done in a way that does not
necessarily guarantee that /proc/self/cmdline will end up NUL-terminated.
However, g_file_get_contents() is documented to fill a buffer of size
len + 1, where buffer[len] == '\0', even if the file's actual contents
(from buffer[0] to buffer[len-1] inclusive) did not include a NUL;
so we can safely relax this assertion slightly.
Resolves: https://gitlab.gnome.org/GNOME/glib/issues/1923
Signed-off-by: Simon McVittie <smcv@collabora.com>
Change a condition from one to an equivalent one to shut up a
`scan-build` warning about potentially dereferencing a `NULL` value.
This introduces no functional changes, as it’s not actually possible to
dereference a `NULL` value here (but `scan-build` can’t link the
nullability of `error` to the nullability of `result`).
Signed-off-by: Philip Withnall <withnall@endlessm.com>
The compiler can’t work out from the combination of other conditions
that it’s not possible for (m2 == NULL) to hold true when memcmp() is
called, so add an explicit condition.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1897
Previously, these GTimeZone objects were being cached in the `time_zones` cache, but dropped from it when their final ref was dropped (which was frequently). That meant additional reads of `/etc/localtime` next time they were created, which was noticeable on profiles. Keep a permanent ref to the UTC and local timezones.
This removes the limitation of select() that only FDs with values lower
than FD_SETSIZE can be used. Previously, if the out/err pipe FDs had
high values (which could happen if a large process, like Firefox, was
spawning subprocesses while having a lot of FDs open), GLib would abort
due to an assertion failure in libc.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #954
glibc declares memcpy() with the first two arguments (the pointers)
annotated as non-null via an attribute, which results in the undefined
behaviour sanitizer considering it to be UB to pass a null pointer
in the second argument, even if we are copying 0 bytes (and hence not
actually dereferencing the pointer).
This shows up in array-test when run with the undefined behaviour
sanitizer.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Note that I deliberately haven't used g_autoptr here, because while we
encourage GLib users to use g_autoptr in their own code, GLib itself
still supports being compiled in environments like MSVC that can't
support g_autoptr.
Signed-off-by: Simon McVittie <smcv@collabora.com>
The user_data for g_ptr_array_sort_with_data is passed directly, not
with an extra layer of pointer like the data pointers.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Fixes: 52c130f8
Let's not encourage library users to sprinkle casts through their code
when they don't need to.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Fixes: 52c130f8
This is like `GMutexLocker`, in that if you are able to use
`g_autoptr()`, it makes popping a `GMainContext` off the thread-default
main context stack easier when exiting a function.
A few uses of `G_GNUC_{BEGIN,END}_IGNORE_DEPRECATIONS` are needed to
avoid warnings when building apps against GLib with
`GLIB_VERSION_MAX_ALLOWED < GLIB_VERSION_2_64`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
We may need to declare autocleanups for new types, which will be marked
as ‘deprecated’ if the code which includes GLib doesn’t declare a high
enough `GLIB_VERSION_MAX_ALLOWED`. Despite that, we still need to
declare the autocleanups.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
The token parsing done by g_variant_parse() uses recursive function
calls, so at some point it will hit the stack limit. As with previous
changes to `GVariantType` parsing (commit 7c4e6e9fbe), limit the level
of nesting of containers parsed by g_variant_parse() to something
reasonable. We guarantee 64 levels of nesting, which should be enough
for anyone, and is the same as what we guarantee for types.
oss-fuzz#10286
Signed-off-by: Philip Withnall <withnall@endlessm.com>
On closer reading of `man 3 timezone`, it’s actually permissible for
`TZ` to contain an absolute path which points to a tzfile file outside
the system time zone database. This is indeed what happens when building
GLib under Fedora’s toolbox, so relax that check in the tests.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
There are a lot of Unix-like systems which have not implemented the
os-release spec. On such system, we can use POSIX uname function as a
fallback to get basic information of the system.
/etc/os-release is a spec designed for Linux. While other OSes can
implement it, it doesn't make sense to use Linux as the default value
on systems which don't use Linux.
Most of the info returned is static, the only thing that changes
is the OS version.
This code relies on g_win32_check_windows_version() providing
accurate information (hopefully, MS won't nix RtlGetVersion() on
which we use for that) and supplements it with information from the
registry for Windows >= 8.1.
In many places the pattern
static gboolean warned_once = FALSE;
if (!warned_once)
{
g_warning ("This and that");
warned_once = TRUE;
}
is used to not spam the same warning message over and over again. Add a
helper in glib for this, allowing the above statement to be changed to
g_warning_once ("This and that");
os-release(5) is widely implemented on Linux, but not necessarily
ubiquitous: unusual or minimal Linux distributions might not have it.
It could in principle be implemented by any other Unix OS, but in
practice this has not yet happened.
Closes: https://gitlab.gnome.org/GNOME/glib/issues/1906
Fixes: 349318e8 "gutils: Add g_get_os_info()"
Signed-off-by: Simon McVittie <smcv@collabora.com>
As an unsigned integer, this variable is always greater than or equal to
zero. Fixes a compiler warning on Android.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
There were tests for the situation where it does the exchange and
returns true, but no tests for the situation where it returns false.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Document that g_vasprintf and g_strdup_printf are guaranteed to return a
non-NULL string, unless the format string contains the locale sensitive
conversions %lc or %ls.
Further annotate that the output parameter for g_vasprintf and the
format string for all functions must be non-NULL.
Fixes#1622
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The g_vasprintf method is called by g_strdup_vprintf, g_strdup_printf,
g_string_append_vprintf and more. It has three different implementations
depending on what the build target platform supports:
1. The gnulib impl appears to use the system malloc, but a
'#define malloc g_malloc' causes it to use GLib's wrapper
and thus abort on OOM. This mostly gets used on Windows
platforms or UNIX platforms with broken printf formatting.
2. The main impl mostly used on modern Linux/UNIX calls the
system vasprintf which uses the system malloc and does not
abort on OOM.
3. The final impl used on remaining platforms calls system
vsprintf on a buffer allocated by g_new, and thus always
aborts on OOM.
Of note is that impl 2 (using vasprintf) historically could abort on
OOM, if the application had installed a non-system malloc impl with
GLib. This was because the code would g_strndup the result from
vasprintf() in that scenario. This was removed in:
commit a366053253
Author: Dan Winship <danw@gnome.org>
Date: Fri Aug 7 09:46:49 2015 -0400
glib: remove deprecated g_mem_is_system_malloc() check in gprintf.c
Having inconsistent OOM behaviour for the three impls is undesirable and
aborting on OOM is normal pratice for GLib APIs. Thus we must thus ensure
this happens in all impls of g_vasprintf.
Fixes#1622
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
These were introducing strict aliasing warnings. Remove them (in line
with other uses of `g_once_init_leave()`).
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Casting pointer types around is a bit fiddly when you also end up
dereferencing them. Take advantage of the fact that the
`__atomic_load()` and `__atomic_store()` built-ins are polymorphic, and
use `__typeof__()` to ensure that the atomic pointer macros use the
caller-provided types internally, and hence any type mismatches are
entirely the caller’s fault rather than ours.
This also means that the `__atomic_{load,store}()` built-ins have the
right alignment and width data from the caller-provided types, in case
that’s needed.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Various places that used atomic functions were using the wrong return
type. Fix that. This introduces no functional changes.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
If we're cross-compiling, the installed-tests are useful even if we
can't run them on the build machine: we can copy them to the host
machine (possibly via a distro package like Debian's libglib2.0-tests)
and run them there.
While I'm changing the build-tests condition anyway, deduplicate it.
Based on a patch by Helmut Grohne.
Bug-Debian: https://bugs.debian.org/941509
Signed-off-by: Simon McVittie <smcv@collabora.com>
`man dup2` says that on Linux, dup2() can return `EBUSY` if the
operation needs to be retried (in addition to returning `EINTR` in other
cases where it needs to be retried).
Signed-off-by: Philip Withnall <withnall@endlessm.com>
All uses of fdwalk in gspawn are between fork and exec, which means only
async-signal safe functions can be called if the parent process has
multiple threads. Since fdwalk is not a standard API, we should not
assume it is safe to use unless the manual of the system explicitly says
it is async-signal safe.
Fixes: #1638
See the mailing list thread <https://lists.fedoraproject.org/archives/list/
devel@lists.fedoraproject.org/thread/SZ676IHHSLOQD6UN2I5J5VKXJ5P5SOVO/>
"glib-2.0 G_CONST_RETURN causing GCC 'warning: const' on F31", where the GCC
diagnostic
> test.c:2:13: warning: const
> 2 | G_CONST_RETURN char * f();
> | ^~~~~~~
had confused me, and "Deprecated pre-processor symbol, repace with const" is
probably a better warning message than just "const".
(That recent GCC only prints "Deprecated pre-processor symbol, repace with "
appears to be a bug in GCC that GLIB_UNAVAILABLE_MACRO already suffers from,
too. Recent Clang correctly prints "Deprecated pre-processor symbol, repace
with const".)
Previously we used the old `__sync_fetch_*()` intrinsics for some of the
atomic operations, such as `g_atomic_int_compare_and_exchange()`. When
available, use the new `__atomic_*()` intrinsics for those instead.
As with the rest of our use of `__atomic_*()` intrinsics, we use the
`__ATOMIC_SEQ_CST` memory model. If people want to use a less
restrictive memory model to get better performance in certain
situations, they can use the compiler intrinsics directly themselves.
`g_atomic_*()` aim to be as fast as possible while remaining general
purpose.
Tested using:
```
meson test --repeat 1000 atomic atomic-test
```
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1750
Android is emitting `-Wtautological-constant-out-of-range-compare`
warnings when compiling the validation functions for the enum types for
`GDate`. Fix that by comparing as integers.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
It was possible to pass in (for example) an invalid year to
g_date_time_new_week(), which would be passed on to g_date_time_new(),
which would (correctly) return `NULL` — but then
g_date_time_get_week_number() would try to dereference that.
Includes a test case.
oss-fuzz#17648
Signed-off-by: Philip Withnall <withnall@endlessm.com>
If the compiler doesn’t provide modern (C++11) atomic builtins (which is
now quite unlikely), we implement our own using the `__sync_synchronize()`
memory barrier. As Behdad and others have pointed out, though, the
implementation didn’t follow the same semantics as we use with the C++11
builtins — `__ATOMIC_SEQ_CST`.
Fix the use of memory barriers to provide `__ATOMIC_SEQ_CST` semantics.
In particular, this fixes the following common pattern:
```
GObject *obj = my_object_new ();
g_atomic_pointer_set (&shared_ptr, obj);
```
Previously this would have expanded to:
```
GObject *obj = my_object_new ();
*shared_ptr = obj;
__sync_synchronize ();
```
While the compiler would not have reordered the stores to `obj` and
`shared_ptr` within the code on one thread (due to the dependency
between them), the memory system might have made the write to
`shared_ptr` visible to other threads before the write to `obj` — if
they then dereferenced `shared_ptr` before seeing the write to `obj`,
that would be a bug.
Instead, the expansion is now:
```
GObject *obj = my_object_new ();
__sync_synchronize ();
*shared_ptr = obj;
```
This ensures that the write to `obj` is visible to all threads before
any write to `shared_ptr` is visible to any threads. For completeness,
`__sync_synchronize()` is augmented with a compiler barrier to ensure
that no loads/stores can be reordered locally before or after it.
Tested by disabling the C++11 atomic implementation and running:
```
meson test --repeat 1000 atomic atomic-test
```
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1449
`g_assert_*()` provide more useful failure messages, and aren’t compiled
out when building with `G_DISABLE_ASSERT`, unlike `g_assert()`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
When compiling GLib with `-Wsign-conversion`, we get various warnings
about the atomic calls. A lot of these were fixed by
3ad375a629, but some remain. Fix them by
adding appropriate casts at the call sites.
Note that `g_atomic_int_{and,or,xor}()` actually all operate on `guint`s
rather than `gint`s (which is what the rest of the `g_atomic_int_*()`
functions operate on). I can’t find any written reasoning for this, but
assume that it’s because signedness is irrelevant when you’re using an
integer as a bit field. It’s unfortunate that they’re named a
`g_atomic_int_*()` rather than `g_atomic_uint_*()` functions.
Tested by compiling GLib as:
```
CFLAGS=-Wsign-conversion jhbuild make -ac |& grep atomic
```
I’m not going to add `-Wsign-conversion` to the set of default warnings
for building GLib, because it mostly produces false positives throughout
the rest of GLib.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1565
Instead of calling close or fcntl on all possible file descriptors,
which is slow on systems with very high limit or even no limit on open
file descriptors, we can use closefrom or fcntl with F_CLOSEM to close
all unwanted file descriptors with a single system call.
This change only improves the performance when GSpawnChildSetupFunc is
NULL because there are applications known to abuse GSpawnChildSetupFunc
to unset FD_CLOEXEC on file descriptors. Since the change mentioned
above requires closing file descriptors directly, it cannot be used when
the caller may want to keep some of them open.
This patch was written by Sebastian Schwarz <seschwar@gmail.com> and
uploaded to https://gitlab.gnome.org/GNOME/glib/merge_requests/574.
It was later modified by Ting-Wei Lan <lantw@src.gnome.org> to address
code review issues.
Fixes: https://gitlab.gnome.org/GNOME/glib/issues/1638
While the introspection scanner can glean the transfer rule for the
return values by looking at their constness, adding an explicit
annotation has the advantage of gtk-doc writing out the transfer rule as
an additional bit of documentation, making the life of the documentation
reader easier.
