9e92ecde74
By making it possible to specify the place in memory where a
type should be constructed, any meta-type can be allocated on
the stack, for example. In the QML/JS QObject binding, this
makes it possible to call slots and access properties from
JavaScript without having to perform any mallocs (e.g. due to
QVariant creation) in the C++ <--> JS value conversion, in
the best case.
In addition to QMetaType::construct() and QMetaType::destruct(),
this change introduces QMetaType::typeSize(), which returns the
size of a type in bytes. This can be used to prepare a suitable
buffer for constructing a type using construct().
Benchmarks indicate that in-place construction is 2-5x faster
than normal construction for core and GUI types on linux-g++.
Note that there is already a QMetaType::construct() function
in Qt 4, which has been renamed to QMetaType::create() in Qt 5.
In order to avoid existing usages of construct() in user code
to call the Qt 5 construct() (when they really meant to call
create()), the third argument ("copy") of construct() is made
mandatory. Hence, calls to QMetaType::construct() written for
Qt 4 will cause a compile error when compiled with Qt 5, and
the user must adapt his code.
Task-number: QTBUG-12574
Change-Id: I836f06f6ee1c1c3edbd199a03424c78c942bdd3e
Reviewed-by: João Abecasis <joao.abecasis@nokia.com>
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>
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| .. | ||
| auto | ||
| baselineserver | ||
| benchmarks | ||
| global | ||
| manual | ||
| shared | ||
| README | ||
| tests.pro | ||
This directory contains autotests and benchmarks based on QTestlib. In order
to run the autotests reliably, you need to configure a desktop to match the
test environment that these tests are written for.
Linux X11:
* The user must be logged in to an active desktop; you can't run the
autotests without a valid DISPLAY that allows X11 connections.
* The tests are run against a KDE3 or KDE4 desktop.
* Window manager uses "click to focus", and not "focus follows mouse". Many
tests move the mouse cursor around and expect this to not affect focus
and activation.
* Disable "click to activate", i.e., when a window is opened, the window
manager should automatically activate it (give it input focus) and not
wait for the user to click the window.