We want to build GLib against a matched version of
gobject-introspection, and this version will probably be bumped quite
often as the two are developed in tandem.
However, if the CI system provides a newer version, we should probably
use that, otherwise we’re essentially downgrading part of the OS on the
CI system, and that probably will result in issues. In particular,
gobject-introspection <1.82 has a bug on MSYS2 which means it doesn’t
build (see issue #3464).
So, build gobject-introspection manually if the CI system version is too
old, otherwise use the system version. Do this programmatically so we
don’t have to repeatedly add and remove the gobject-introspection build
commands from the CI configuration as versions are bumped.
Fixes: #3464
This option was renamed to `branch_coverage` in more recent versions of
lcov. This might explain why branch coverage is not being collected by
CI at the moment.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Now that the implementation of it is significantly more complex,
involving pointer arithmetic, it should probably be fuzzed. It’s not an
API which is obviously used to handle untrusted input, but some users of
GLib might do so.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Current implementation replaces find in string with replace
one-at-a-time and replacement is done in O(n^2) time. The new
implementation is O(n). Memory allocation is done once instead of
incrementally.
In the old implementation, every replacement will move the whole
rest of the string from the current position to make space for
the replace string and then insert the replace string.
In the new implementation, when the replace string is shorter or equal
to the find string, it will move the characters in-place and requires no
additional memory. When the replace string is longer, find the required
size needed for the new string and preallocate a new string to copy the
original string to with its replacements. When the replace string is an
empty string use the old implementation to handle the special case.
This is better than using `g_getenv ("DBUS_SESSION_BUS_ADDRESS")` as it
will fail more explicitly if the mock bus somehow isn’t running.
This will be used in an upcoming commit.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Previously, all GVariants would allocate a GBytes for the buffered
contents. This presents a challenge for small GVariant type created
during the building process of GVariantBuilder as that results in an
allocation for the GVariant, GBytes, and the byte buffer.
Recent changes for GBytes may reduce those 3 allocations to 2, but even
that is quite substantial overhead for a 32-bit integer.
This changeset switches GVariant to use g_new/g_free allocators instead
of g_slice_new/free. When benchmarked alone, this presented no
measurable difference in overhead with the standard glibc allocator.
With that change in place, allocations may then become variable in size
to contain small allocations at the end of the GVariant reducing things
to a single allocation (plus the GVariantTypeInfo reference).
The size of GVariant is already 1 cacheline @ 64-bytes on x86_64. This
uses that to guarantee our alignment of data maintains the 8-bytes
guarantee of GVariant, and also extends it to match malloc().
On 32-bit systems, we are similarly aligned but reduce the amount we
will inline to 32 bytes so we have a total of 1 cacheline.
This is all asserted at compile-time to enforce the guarantee.
In the end, this changeset reduces the wallclock time of building many
GVariant in a loop using GVariantBuilder by 10% beyond the 10% already
gained through GBytes doing the same thing.
Now that the CI runner has Meson 1.4, we can revert commit
eda5bb386b and re-enable fatal warnings.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
All uses of g_variant_builder_init() in gio are safe to translate to the
new g_variant_builder_init_static() alternative as the type will outlive
the call to g_variant_builder_end() (or is already static in nature).
Make the generated GDBus-based code use GVariantBuilder with a static
GVariantType to avoid copying the GVariantType on each use.
This is gated behind a GLib 2.83.0 check.
This adds another form of stack building which allows avoiding the rather
expensive GVariantType malloc/memcpy/free. In a tight loop this reduced
wallclock time by about 4-5% for cases where you do not need to further
open using g_variant_builder_open() which still require a copy at this
time.
New API is provided instead of modifying g_variant_type_init() because
previously it was possible (though misguided) to use g_variant_type_init()
which a dynamically allocated GVariantType which could be freed before
g_variant_builder_end() or g_variant_builder_clear() was called.
# Conflicts:
# glib/gvariant.c
When trying to locate a GVariantTypeInfo from the cache we were copying
the string so that we can use g_str_hash, as that requires a \0 terminated
string.
However, we have hash and equal functions which can be used without the
extra copy. Additionally, these were moved to headers in previous commits
so they can be used without having to re-check GVariantType we already
know to be valid.
Use the [provide] section to override the binary name, and track the
main development branch, like GTK does, so we get warnings and a
consistent output.
It's better to warn by default on MSVC (which we were already doing before
we bumped to 1.4.0) than to fail by default on macOS.
Fixes: 51e3e7d9ae ("build: Bump Meson dependency to 1.4.0")
As with the previous commit, this is _always_ defined in `gmacros.h`
and therefore the `#ifndef` will always be 0 even if disabled.
Just use `#if` instead.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Right now we create a bunch of GBytes which then get their reference count
incremented and immediately decremented. This causes quite a bit of
disruption for cacheline re-use.
Instead, this change creates an internal helper to transfer ownership of
GBytes to the new GVariant directly.
Surprisingly, this reduced wallclock time by about 6% for a contrived
benchmark of building "as" variant with GVariantBuilder.
When dealing with small allocations it can save considerable cycles to
do a single allocation for both the GBytes and the data by tacking it
onto the end of the GBytes.
Care is taken to preserve the glibc expectation of 2*sizeof(void*)
alignment of allocations at the expense of some padding bytes.
The degenerate case here is when you want to steal the bytes afterwards
but that amounts to the same overhead as the status-quo.
Where this can help considerably is in GVariant building such as
g_variant_new_int32() which allocates for the GVariant, the GBytes, and
the int32 within the GBytes.
In a simple benchmark of using GVariantBuilder to create "(ii)" variants
this saved about 10% in wallclock time.
