Qemu uses some memory for each generated thread. This test creates
> 80000 threads and consumes about 10Gb of memory which is too
heavy for a VM.
Task-number: QTBUG-59966
Change-Id: I1bb8a0d7955778f5201948b41befcb9f1f391514
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
In the spirit of std::thread, which takes a function to call and its
parameters, and runs it in a new thread. Since the user might want to
connect to signals, move QObjects into the new thread, etc., the new
thread is not immediately started.
Although technically all of this _should_ be implementable in pure
C++11, there is nothing in the Standard to help us not reinvent all the
plumbing: packing the decay'd parameters, storing them, invoking the
function over the parameters (honoring INVOKE/std::invoke semantics).
std::function does not do the job, as it's copiable and therefore does
not support move-only functors; std::bind does not have INVOKE
semantics.
I certainly do not want to reimplement all the required facilities
inside of Qt. Therefore, the full blown implementation requires C++17
(std::invoke).
In order to make this useful also in pre-C++17, there are two additional
implementations (C++11 and C++14) that support just a callable, without
any arguments passed to it. The C++11 implementation makes use of a
class to store and call the callable (even move-only ones); basically,
it's what a closure type for a C++14 lambda would look like.
An alternative implementation could've used some of the existing
facilities inside QObject::connect implementation that store a functor
(for the connect() overload connecting to free functions), namely:
the QtPrivate::QFunctorSlotObject class. However:
* QFunctorSlotObject does not support move-only callables (see
QTBUG-60339);
* QFunctorSlotObject itself is not a callable (apparently by design),
and requires to be wrapped in a lambda that calls call() on it;
* the moment QTBUG-60339 is solved, we'd need the same handwritten
closure to keep QFunctorSlotObject working with move-only callabes.
So: just use the handwritten one.
The C++14 implementation is a simplified version of the C++11 one,
actually using a generalized lambda capture (corresponding to the
handwritten C++11 closure type).
All three implementations use std::async (with a deferred launch policy,
a nice use case for it!) under the hood. It's certainly an overkill for
our use case, as we don't need the std::future, but at least std::async
does all the plumbing for us.
[ChangeLog][QtCore][QThread] Added the QThread::create function.
Change-Id: I339d0be6f689df7d56766839baebda0aa2f7e94c
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
The keyword no longer has a meaning for the new CI.
Change-Id: Ibcea4c7a82fb7f982cf4569fdff19f82066543d1
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>
Qt 5.0 beta requires changing the default to the 5.0 API, disabling
the deprecated code. However, tests should test (and often do) the
compatibility API too, so turn it back on.
Task-number: QTBUG-25053
Change-Id: I8129c3ef3cb58541c95a32d083850d9e7f768927
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
qttest_p4.prf was added as a convenience for Qt's own autotests in Qt4.
It enables various crufty undocumented magic, of dubious value.
Stop using it, and explicitly enable the things from it which we want.
Change-Id: I7c1ffe9c8c294dbdc988e1582e580b1ed3f4593e
Reviewed-by: Jason McDonald <jason.mcdonald@nokia.com>
Symbian is not a supported platform for Qt5, so this code is no longer
required.
Change-Id: I1172e6a42d518490e63e9599bf10579df08259aa
Reviewed-on: http://codereview.qt-project.org/5657
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>
Liang Qi
Sami Nurmenniemi
Giuseppe D'Angelo
Friedemann Kleint
Thiago Macieira
Jason McDonald
Rohan McGovern
Holger Ihrig