[Development] Evolving Qt's multithreading API

[Sze Howe Koh]

On 20 February 2013 22:45, Sze Howe Koh <szehowe.koh at gmail.com> wrote:
> Hi all,
>
> Some time ago there was some talk about improving Qt's multithreading
> API. I'm summarizing them here to stop them from fading into
> obscurity, and to see if there's any interest in following them up.
>
> Here are the tasks mentioned:
> - Replace/Rewrite QtConcurrent [2]
> - Create/Find a good API to replace QtConcurrent::run() for "one-shot" tasks [1]
> - Find a third-party solution for high-level multithreading [2]
> - Find more uses for QFuture, outside of QtConcurrent [3]
> - Influence C++1y by creating a nice multithreading API [4]
>
> Some suggestions were raised:
> - Put a Qt-ish wrapper around TBB [1]
> - Integrate ThreadWeaver back into Qt? [2]
>
> Separately, someone was experimenting with ways to spawn a QObject in
> a secondary thread, without first constructing it in the current
> thread [5]
>
>
> Do you think any of these avenues are worth pursuing?
>
> I've had a quick look at TBB vs. ThreadWeaver. The latter specializes
> in task-oriented programming, while TBB is a more swiss-army-knife
> toolkit, which includes container-based operations similar to
> QtConcurrent. So, if we're to integrate 3rd-party option into Qt, TBB
> would be more worth it (although it'd involve more work too)

Actually, I just realized that the open-source "flavour" of TBB is
licensed under GPLv2 (http://threadingbuildingblocks.org/Licensing).
Doesn't that mean that Qt TBB, if it were to become reality, can't be
licensed under the LGPL?


> Regards,
> Sze-Howe
>
> [1] http://lists.qt-project.org/pipermail/development/2012-November/007901.html
> [2] http://lists.qt-project.org/pipermail/development/2012-November/007921.html
> [3] http://lists.qt-project.org/pipermail/development/2012-November/007944.html
> [4] http://lists.qt-project.org/pipermail/development/2012-November/007933.html
> [5] http://lists.qt-project.org/pipermail/interest/2013-January/005740.html