From e53a3bd85afb0e140aa4b89925345c33dc464bf5 Mon Sep 17 00:00:00 2001 From: Sona Kurazyan Date: Thu, 29 Oct 2020 10:11:10 +0100 Subject: Move porting guide for QtConcurrent to its designated page MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Also move the porting section for QFuture and related classes after the section for view classes, to make the order more natural for reading. Change-Id: I5ea816d7bb3dfdda2b74112418bf07954c9ec94c Reviewed-by: Jarek Kobus Reviewed-by: Mårten Nordheim --- src/corelib/doc/src/qt6-changes.qdoc | 109 ++++++++++++----------------------- 1 file changed, 38 insertions(+), 71 deletions(-) (limited to 'src/corelib/doc') diff --git a/src/corelib/doc/src/qt6-changes.qdoc b/src/corelib/doc/src/qt6-changes.qdoc index cdbb86cc21..6354737249 100644 --- a/src/corelib/doc/src/qt6-changes.qdoc +++ b/src/corelib/doc/src/qt6-changes.qdoc @@ -176,77 +176,6 @@ to cases where QVector or QList with a non C-compatible array layout were used originally. - \section1 QtConcurrent and Related Classes - - \section2 QFuture and QFutureWatcher - - In Qt 6, there are no changes that introduce source compatibility breaks - in code that was using QFuture and QFutureWatcher classes. However there - were some improvements which caused the following behavioral changes: - - \list - - \li After pausing QFuture or QFutureWatcher (by calling \c pause() or - \c setPaused(true)), QFutureWatcher will not immediately stop delivering - progress and result ready signals. At the moment of pausing there may be - still computations that are in progress and cannot be stopped. Signals - for such computations may be still delivered after pause, instead of being - postponed and reported only after next resume. To get notified when pause - actually took effect, QFutureWatcher::suspended() signal can be used. In - addition, there are new \c isSuspending() and \c isSuspended() methods, - to check if the QFuture is in the process of suspending or it's already in - the suspended state. Note that for consistency reasons, for both QFuture - and QFutureWatcher the pause-related APIs were deprecated and replaced by - similar methods having "suspend" in the name instead. - - \li QFuture::waitForFinished() will now wait until QFuture is actually in - the finished state, instead of exiting as soon as it is not in the running - state. This prevents \c waitForFinished() from exiting immediately, if at - the moment of calling it the future is not started yet. The same applies to - QFutureWatcher::waitForFinished(). This change won't affect the behavior of - code that was using QFuture with QtConcurrent. Only the code that was using - it with the undocumented \c QFutureInterface may be affected. - - \endlist - - \section2 QPromise - - In Qt 6, the new QPromise class should be used instead of unofficial - QFutureInterface as a "setter" counterpart of QFuture. - - \section2 QtConcurrent::run() - - QtConcurrent::run() has been improved to work with a variable number - of arguments, so the signatures are changed to: - - \code - // run - template - QFuture run(Function &&f, Args &&...args) - - // run with a QThreadPool argument - template - QFuture run(QThreadPool *pool, Function &&f, Args &&...args) - \endcode - - As a side effect, if \c f is a pointer to a member function, the first - argument of \c args should be the object for which that member is defined - (or a reference, or a pointer to it). So instead of writing: - - \code - QImage image = ...; - QFuture future = QtConcurrent::run(&image, &QImage::invertPixels, QImage::InvertRgba); - \endcode - - You have to write: - - \code - QFuture future = QtConcurrent::run(&QImage::invertPixels, &image, QImage::InvertRgba); - \endcode - - Other methods of QtConcurrent have no behavioral changes and do not introduce - source compatibility breaks. - \section1 View classes in Qt6 \section2 General Overview @@ -464,6 +393,44 @@ } \endcode + \section1 QFuture and Related Classes + + \section2 QFuture and QFutureWatcher + + In Qt 6, there are no changes that introduce source compatibility breaks + in code that was using QFuture and QFutureWatcher classes. However there + were some improvements which caused the following behavioral changes: + + \list + + \li After pausing QFuture or QFutureWatcher (by calling \c pause() or + \c setPaused(true)), QFutureWatcher will not immediately stop delivering + progress and result ready signals. At the moment of pausing there may be + still computations that are in progress and cannot be stopped. Signals + for such computations may be still delivered after pause, instead of being + postponed and reported only after next resume. To get notified when pause + actually took effect, QFutureWatcher::suspended() signal can be used. In + addition, there are new \c isSuspending() and \c isSuspended() methods, + to check if the QFuture is in the process of suspending or it's already in + the suspended state. Note that for consistency reasons, for both QFuture + and QFutureWatcher the pause-related APIs were deprecated and replaced by + similar methods having "suspend" in the name instead. + + \li QFuture::waitForFinished() will now wait until QFuture is actually in + the finished state, instead of exiting as soon as it is not in the running + state. This prevents \c waitForFinished() from exiting immediately, if at + the moment of calling it the future is not started yet. The same applies to + QFutureWatcher::waitForFinished(). This change won't affect the behavior of + code that was using QFuture with QtConcurrent. Only the code that was using + it with the undocumented \c QFutureInterface may be affected. + + \endlist + + \section2 QPromise + + In Qt 6, the new QPromise class should be used instead of unofficial + QFutureInterface as a "setter" counterpart of QFuture. + \section1 IO Classes \section2 QProcess -- cgit v1.2.3