- fix and improve usage output for "performance-run.sh" script.
- add a sleep after compilation. It seems to me, that the first run
usually performs better, which might be because the temperature of the
CPU raises and the CPU gets throttled. Unclear whether that is really
the case, but add a sleep so that all runs start under similar
conditions where the CPU was idle for a moment.
When running the test (without parameters), it estimates a factor for
the run size for each test. That is useful for running a reasonable size
of the test, on different machines.
However, when comparing two runs, it seems important that both runs
share a common factor. Otherwise, the factor is determined differently,
and the test is less comparable. For that there is the "--factor" option
or the GLIB_PERFORMANCE_FACTOR environment variable.
However, the factor option can only set the factors for all tests at the
same time. Optimally, one factor is roughly suitable for all tests, but
it is not, as currently the detected factors on my machine are widely
different
$ ./build/gobject/tests/performance/performance -v > p
$ cat p | sed -n -e 's/^Running test //p' -e 's/.*correction factor //p' | sed 'N;s/\n/ /'
simple-construction 34.78
simple-construction1 145.45
complex-construction 11.08
complex-construction1 20.46
complex-construction2 23.74
finalization 4.74
type-check 37.74
emit-unhandled 5.63
emit-unhandled-empty 49.69
emit-unhandled-generic 7.17
emit-unhandled-generic-empty 50.63
emit-unhandled-args 5.20
emit-handled 3.86
emit-handled-empty 4.01
emit-handled-generic 3.96
emit-handled-generic-empty 7.04
emit-handled-args 3.78
notify-unhandled 52.63
notify-by-pspec-unhandled 156.86
notify-handled 2.55
notify-by-pspec-handled 2.66
property-set 34.63
property-get 32.92
refcount 0.83
refcount-1 2.30
refcount-toggle 1.33
Adjust the base factors with these measurements.
PERFORMANCE_FILE="./gobject/tests/performance/performance.c"
IFS=$'\n'
for LINE in $(cat p | sed -n -e 's/^Running test //p' -e 's/.*correction factor //p' | sed 'N;s/\n/ /') ; do
(
IFS=' '
set -- $LINE
TESTNAME="$1"
FACTOR="$2"
LINENUMBER="$(grep -n "^ \"$TESTNAME\",$" "$PERFORMANCE_FILE" | cut -d: -f1)"
LINENUMBER=$((LINENUMBER + 2))
OLD_FACTOR="$(sed -n "$LINENUMBER s/^ \([0-9]\+\),$/\1/p" "$PERFORMANCE_FILE")"
NEW_FACTOR="$(awk -v factor="$FACTOR" -v old_factor="$OLD_FACTOR" 'BEGIN {print int(factor * old_factor + 0.5)}')"
sed -i "$LINENUMBER s/^ \([0-9]\+\),$/ $NEW_FACTOR,/" "$PERFORMANCE_FILE"
)
done
Afterwards, we get comparable factors:
$ ./build/gobject/tests/performance/performance -v > p2
$ cat p2 | sed -n -e 's/^Running test //p' -e 's/.*correction factor //p' | sed 'N;s/\n/ /'
simple-construction 0.98
simple-construction1 0.75
complex-construction 0.99
complex-construction1 0.96
complex-construction2 1.02
finalization 1.05
type-check 0.98
emit-unhandled 1.01
emit-unhandled-empty 1.10
emit-unhandled-generic 1.03
emit-unhandled-generic-empty 1.07
...
Of course, this measurement was taken in my setup. But I think it
brings the base factors into a comparable range for most users.
Also, the commit message shows an ugly script how you can re-generate
this for your own purposes.
Move the factor inside the PerformanceTest structure, so it can be
programatically accessed.
More importantly, the number is now expressed directly beside the test
setup (the PerformanceTest structure), all at one place.
Also, each test now gets a separate factor.
This change will be useful in the next commit. So far there is no
notable change in behavior.
Despite assigning the function to a variable, gcc can still detect that
the function never changes and most of the test code is optimized out.
Initialize it somewhere, where the compiler cannot prove that this
function pointer is always set to the same value.
We could also make the pointer volatile, but this approach seems
preferable to me.
The documentation in GLib of iconv is forgivably brief. Advanced users (e.g.
for streaming use, for which this API is recommended over the simpler GLib
APIs) will want to know more detail about what happens when there’s an
error: without knowing, you can’t really use this function for streaming.
Point to both iconv(3posix), which gives the fully-portable details, i.e.
all that a user of GLib can rely on, and iconv(3), which is rather easier to
read, and may be of interest to those writing GNU-specific code, or who know
that their GLib is built with libiconv.
The API already promises that it’s the “[s]ame as the standard UNIX routine
iconv()”, so it’s quite safe to point to the relevant man pages; looking at
the source code bears this out, as g_iconv merely calls iconv.
Cache the function pointer for g_datalist_id_update_atomic() in a static
variable in "gobject.c" to avoid looking it up repeatedly.
g_datalist_id_update_atomic() is anyway internal API. Like GData is not
a useful data structure in general, this function is only useful for
something specific inside GObject.
It can be easily seen that _local_g_datalist_id_update_atomic is never
read without having a GObject at hand (because we call it on
`&object->qdata`). Thus initializing the pointer in
g_object_do_class_init() (under lock) is sufficient to ensure
thread-safe initialization. Note that we still set the pointer via
g_atomic_pointer_set(). This is done in an attempt to pacify thread
sanatizer.
Note that also with LTO enabled, the GLIB_PRIVATE_CALL() call cannot be
inlined. Previously we get:
0000000000011300 <_weak_ref_set>:
...
1131d: e8 ee 03 ff ff call 1710 <glib__private__@plt>
11322: 8b 35 0c b2 05 00 mov 0x5b20c(%rip),%esi # 6c534 <quark_weak_locations.lto_priv.0>
11328: 4c 89 e1 mov %r12,%rcx
1132b: 49 8d 7c 24 10 lea 0x10(%r12),%rdi
11330: 48 8d 15 b9 42 ff ff lea -0xbd47(%rip),%rdx # 55f0 <weak_ref_data_get_or_create_cb.lto_priv.0>
11337: ff 90 80 00 00 00 call *0x80(%rax)
afterwards:
0000000000011300 <_weak_ref_set>:
...
1131d: 48 8d 7e 10 lea 0x10(%rsi),%rdi
11321: 48 89 f1 mov %rsi,%rcx
11324: 48 8d 15 c5 42 ff ff lea -0xbd3b(%rip),%rdx # 55f0 <weak_ref_data_get_or_create_cb.lto_priv.0>
1132b: 8b 35 0b b2 05 00 mov 0x5b20b(%rip),%esi # 6c53c <quark_weak_locations.lto_priv.0>
11331: ff 15 f9 b1 05 00 call *0x5b1f9(%rip) # 6c530 <_local_g_datalist_id_update_atomic.lto_priv.0>
Also note, that the point here is not to optimize _weak_ref_set() (which
is not a hot path). There is work in progress that will use
g_datalist_id_update_atomic() for more purposes (and during more
relevant code paths of GObject).
This documentation used to link to GLib’s TAP harness. However, the built-in
Automake support works fine, and is simpler to use. Hence, remove most of
the old documentation, and refer users to the Automake manual, adding just
one hint for use with GLib.
During "as-installed" testing, we should search the GIR_DIR for GIR XML,
instead of hard-coding that it is `${prefix}/share/gir-1.0`. This is
not the case on at least Debian, in order to make it possible to
install more than one architecture's flavour of `GLib-2.0.gir`,
which contains some architecture-specific `#define`s.
Also search GOBJECT_INTROSPECTION_DATADIR/GIR_SUFFIX (in practice
something like `/usr/share/gir-1.0` in all cases) to accommodate
distributions like Debian that move the architecture-independent
majority of GIR XML into /usr/share to avoid duplication, leaving
only the architecture-specific minority of files like `GLib-2.0.gir`
in the GIR_DIR.
Signed-off-by: Simon McVittie <smcv@collabora.com>
None of the users actually care about this parameter. And it's unlikely
that they ever will. Also, the passed "key_id" is the argument from
g_datalist_id_update_atomic(). If the caller really cared to know the
"key_id" in the callback, they could pass it as additional user data.
In some sense, it might be desirable to always initialize out parameters
to something.
However, this fallback index G_MAXUINT32 is not really useful for any
caller. That is, no caller can blindly access the index without checking
whether datalist_find() found (and returned) an entry.
Also, a caller cannot check for whether a entry was found via `if (idx
== G_MAXUINT32)`, because that theoretically is also a valid index.
The only sensible way to use datalist_find() is by accessing "idx"
if-and-only-if an entry was found. And all callers did that.
There is no point for initializing the value.
Uninitialized values can be even preferable over a non-useful
initialization to G_MAXUINT32, because if there is a buggy access them
under valgrind, there will be at least a warning.
The code comment was no longer correct. g_data_remove_internal() does
not depend on this anymore. It also just calls datalist_find(), which
searches the entire list.
The code comment was correct in the past, and how the code was then we
had to ensure the array is initialized.
This is no longer the case. We will only access the array at the indexes
from zero to up to (found_keys-1). And those places get always
initialized before we use them (as we increment found_keys at the same
time).
There is no longer a need to initialize this array to zero. Drop this.
Fixes: 3437414dd4f7 ('gdataset: use lookup index in g_datalist_id_remove_multiple()')
We use flags in both locked paths and in public ones (to check if a
source is destroyed or running), but those checks are not using atomic
logic, thus they lead to races in various tests.
Fix them by atomically change and read the values.
And this fixes various tests in thread sanitizer.
