Drop addSub() test. It executes exactly the union of fetchAndAdd()
and fetchAndSub(), which have already had their UBs fixed.
No need to do fixes in duplicated code.
Change-Id: Ib72caab0310fce3ff9a40c261d8a38518f91ecaf
Reviewed-by: David Faure <david.faure@kdab.com>
Signed integer overflows and underflows are undefined
behavior. A test that invokes UB tests nothing, because
the standard permits any outcome.
Fix by guarding the respective operations so
they are not executed if they would overflow
or underflow.
Change-Id: I40354ee88f40e4b47b70eac7790dc3a79ac70a57
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
And add tests for the GCC intrinsics and for std::atomic.
Task-number: QTBUG-43794
Change-Id: Ic5d393bfd36e48a193fcffff13b9b2dbaee80469
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
Qt copyrights are now in The Qt Company, so we could update the source
code headers accordingly. In the same go we should also fix the links to
point to qt.io.
Outdated header.LGPL removed (use header.LGPL21 instead)
Old header.LGPL3 renamed to header.LGPL3-COMM to match actual licensing
combination. New header.LGPL-COMM taken in the use file which were
using old header.LGPL3 (src/plugins/platforms/android/extract.cpp)
Added new header.LGPL3 containing Commercial + LGPLv3 + GPLv2 license
combination
Change-Id: I6f49b819a8a20cc4f88b794a8f6726d975e8ffbe
Reviewed-by: Matti Paaso <matti.paaso@theqtcompany.com>
Change-Id: I91ff06644e8047c2ca483f9768b46c1372eb6171
Reviewed-by: Martin Smith <martin.smith@digia.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@theqtcompany.com>
MSVC 2008 is confused by TypeInStruct being a template, resulting in
\tst_qatomicinteger.cpp(189) : error C2027: use of undefined type 'QStaticAssertFailure<Test>'
with
[
Test=false
]
for int (and thus for all unsupported types). This appears to be a real
Heisenbug-nature compiler bug as it can also be fixed by adding
qDebug() << Q_ALIGNOF(TypeInStruct<T>)
before the static assert.
Task-number: QTBUG-37195
Change-Id: Ib2b60f3c1ffeb0b8bdeb1fb0c659655ce4ab10d8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This is extremely useful, since the most common action after a failed
compare-and-swap is to loop around, trying again with the current
value as found in memory.
Code currently written as:
do {
Type value = atomic.load();
...
} while (!atomic.testAndSetRelaxed(value, desired));
Becomes:
Type value = atomic.load();
do {
...
} while (!atomic.testAndSetRelaxed(value, desired, value));
In most CPU architectures, the value that was found in memory is known
to the compare-and-swap code, so this is more efficient than the
previous code. In architectures where the value is not known, the new
code is no worse than before.
The implementation sometimes modified an existing function, sometimes
it added a new one, depending on whether more registers were needed in
the assembly (like ARMv6-7), the code became more complex (ARMv5), the
optimizer failed (C++11), or it was just plain equivalent (MIPS).
Change-Id: I7d6d200ea9746ec8978a0c1e1969dbc3580b9285
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This simplifies the code a lot and avoids silly mistakes where a
specific integer type is missing (such as char16_t).
Change-Id: Id91dfd1919e783e0a9af7bfa093ca560a01b22d1
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
