Tag Archives: kde community

KDE Akademy 2014 – Welcome, new KDE board!

Akademy 2014 is still in full swing in Brno in the Czech Republic with the traditional hack week that started on Monday. At about 200 participants it was well attended and organized. This years conference will very likely mark a milestone of change for KDE – a new board was elected, and a strategy discussion was started that will affect the direction and development of the KDE community for a decent amount of time. When I traveled home from Akademy 2014 on the train from Brno to Berlin, I personally felt a sense of satisfaction, because the community has managed to steer clear of the dangers of bike shedding about the board succession, and is accepting the change imposed by a shifting environment as a positive force.

Akademy 2014

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How to contribute to the KDE Frameworks Cookbook

The annual KDE Randa Meeting, in itself already shock-ful of awesome, this year hosted the KDE Frameworks Cookbook sprint. Valorie, Cornelius and I already wrote a lot about it. Plenty of attention went into finding the place for the cookbook between the getting-started HOWTOs on KDE Techbase and the full-blown API documentation. Not surprisingly, there is a space and a good purpose for the book. Frameworks developers and maintainer have had to deal with the question of where to put introductions that segue newcomers into how to use the modules many times, and so far, the answer have been unsatisfactory. Newcomers only find the API documentation when they already know about a framework, and TechBase is a great resource for developers, but not necessarily a good introduction. What is missing is a good way to help and learn about what KDE Frameworks have to offer. So there is the purpose of the KDE Frameworks Cookbook – to help developers find and learn about the right tools for the problems they need to solve (and also, consumable on a e-book reader by the pool). For developers and maintainers, this means they need to know how to add sections to the book that cover this information about their frameworks. These tools and workflows will be explained in this post. Continue reading

KDE Frameworks Book Sprint at the Randa Meeting 2014

A couple of weeks before the KDE Randa Meeting of 2014, the meeting’s organizer Mario Fux suggested to have a book sprint to help developers adopt the newly released KDE 5 Frameworks. In the Open Source spirit, the idea was not to start from scratch, but rather to collect the various bits and pieces of documentation that exist in different places in one location that offers itself more to a developer than before. Valorie Zimmermann stepped up to organize it (many thanks!), and a number of people volunteered to take part. After a week the project completely changed its orientation and struggled and found and also newly defined its place as a part of KDE’s documentation efforts. And it produced an initial version of the book, which is currently circulated on people’s ebook readers around here. Continue reading

KDE Frameworks 5 Tech Preview released, with updated ThreadWeaver

Today, the KDE Community released a tech preview of the upcoming KDE 5 Frameworks, the new, modularised incarnation of what was previously distributed simply as the KDE libraries. The new frameworks are drop-in extensions to Qt applications, with minimal and well-documented dependencies for easier deployment. The tech preview contains two frameworks that are marked as mature, namely KArchive and ThreadWeaver. The updated ThreadWeaver was my major piece of library coding work in 2013, and was finished just in time for the release. Even though it is a tech preview, it is stable, and no major (or even significant but minor) changes in the current API are expected until the final release. Programmers are already encouraged to use it, and provide feedback and bug reports.

2897019812_c6bddd5fb1_oThreadWeaver is a concurrent execution scheduler written in C++. Available for all target platforms of the Qt framework, including desktop, mobile and embedded environments, ThreadWeaver delivers concurrent execution of tasks, load balancing with regard to user-defined criteria, multiple independent queues, processing graph modelling, aggregate jobs and other comprehensive features. As all other KDE frameworks, ThreadWeaver is Free Software. Its only dependency is Qt, which makes it a tier 1 framework in KDE’s lingo.

A number of the new features of ThreadWeaver were announced at Akademy 2013. Jobs, the unit of concurrent execution in ThreadWeaver, are now managed by the queue using shared pointers, meaning that auto-delete behaviour is implicit and controlled by the user. Helper templates are available to queue stack or member variables, so allocation of jobs can be static or dynamic. Functors or lambda functions can be used to construct jobs. Job aggregates like collections and sequences now execute their own run() method before queueing their elements, so that aggregates can generate their own elements. Success and queueing state of jobs are now integrated into a single status. Jobs can signal the result of execution by setting a status, but also using exceptions, simplifying error reporting in more complex job classes. Jobs can be decorated, and no more inherit QObject by default. Decorators can be used to add signals, change priorities or modify just about any behaviour of jobs independently of the actual job class used. The construction of the global queue can now be customised using a queue factory. The QueueStream API greatly simplifies queueing jobs with a familiar iostream-like C++ syntax.

ThreadWeaver follows the Unix idiom of doing one thing, and doing it right. Similar to how small Unix programs can be combined to create an practically infinite space of computing solutions, ThreadWeaver offers itself to programmers as an add-on module with minimal dependencies. Including it extends an application with concurrent scheduling capability. But the same Unix idiom is also applied in a second sense. Within ThreadWeaver, a few basic concepts – jobs and their aggregates, queues and policies – are implemented that again provide simple building blocks that can be combined creatively, offering a vast space of potential solutions within the scope of the application.

The history of ThreadWeaver goes back to KDE 3. The idea of implementing a thread pool based execution scheduler that manages dependencies between jobs was implemented as a proof of concept using Qt 3. However it turned out to be difficult to implement and use because of the lack of thread-safe reference counting of the implicitly shared classes at the time. These fundamental problems have been solved with the release of Qt 4. Additionally, the introduction of cross-thread signal-slot connections further simplified the communication between jobs and the application’s user interface. The first production ready version of ThreadWeaver was released as part of KDELibs with KDE 4.0. For KDE Frameworks 5, it was almost completely re-written to simplify memory management of jobs, make use of new Qt 5 features like atomic variables, and in part to reflect new language constructs in C++11 like lambda functions. ThreadWeaver comes with an extensive set of unit tests that all pass in the tech preview (hear, hear).

In the following weeks and months, the framework will be polished and debugged based on user feedback. Also, a series of posts here on this blog will introduce individual ThreadWeaver concepts and features in depth, mostly based on example programs, including contrasting it to thread handling in Qt using QThread or Qt Concurrent. ThreadWeaver is very close to production quality, having been tested continuously in the last couple of months. There may still be smaller, source compatible changes to the framework. We ask interested programmers out there to provide feedback and bug reports to make ThreadWeaver what it should be — a worry-free, easy to use and powerful add-on to Qt that programmers enjoy using. Have fun!

[Image by Shannan Sinclair, thanks: http://www.flickr.com/photos/originalbliss/2897019812%5D


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Frismakers Festival Berlin – “Open Source as a corporate culture”

Is it possible to convey an idea comprehensively  in 5 minutes? The Frismakers movement seems to think so. I had a chance to try it at the recent Frismakers Festival in Berlin, where I presented on how we apply the Open Source way to build Endocode and its corporate culture. This was a challenge for the five minute format because it is just not a trivial idea.

Endocode Frismakers PresentationThe question I raised in the talk was how experienced Open Source contributors would design a company. When asked about what motivates them, contributors often say it is the sense of creative accomplishment and working with others that share their interests. When we started Endocode, we wanted to retain and channel that kind of intrinsic motivation. While others are searching for the Open Source business model, we wanted to create a business that allowed us to work in the Open Source Way, a place where contributors like us would want to work. Among other things, this means implementing meritocracy, open governance and attribution. Meritocracy boils down to having influence that matches your contributions. In our case, it means for example that all employees gather share in the company according to how long they have been with us. Open governance is not anarchy, quite contrary it is implemented by having well defined, inclusive decision making processes. Attribution is a bit harder to implement, the contributions of individuals in Endocode should be visible, instead of the individuals disappearing in the machine like cogs. At Endocode, we actively strive to follow these principles while the company is growing. So far, our employees agree with us that Endocode is a great place to work.

The idea of creating a place for meaningful contributions and calling that a company induced a number of thoughtful questions and comments. It also raised attention in unexpected places, for example TechNet. One attendee raised doubts on whether our goals can be achieved. To that the answer is we do not know yet. Building a work place driven by purpose is a process, not a one-time effort. Companies change and grow. What we do want to do is keep these ideals in mind for future design decisions, and strive for it. I hope we can review the results in ten years time.

The festival was expertly organized by Anna-Lena König and Daniela Bentrup of newthinking communications, who together with host Gallup Germany made it a great experience.

So does the Frismakers concept work? During the preparation of the talk, I found it quite hard to identify those bits of the train of thought that absolutely have to be presented to the viewer. Of course that enforces the presenter to weed out all the cruft. On the other hand I had the feeling that it would have been easier to understand the presentation in ten minutes than in five. For example, when removing a few of the comments I usually add, I firmly expected that interested people in the audience will ask questions about that after the talk. And that is exactly what happened. This means that those who did not have time to ask afterwards won’t get the full picture, or go home unsatisfied. Consequently, I am sure that there is a class of ideas that can nicely and profoundly presented in five minutes. This class however is a subset of all (potentially interesting) ideas, and I have the impression that it does not contain all the really fascinating ones. The five minute concept seems to be more suitable for product presentations and start-up pitches. Not bad per se, but something to keep in mind. TED talks have been claimed to “turn scientists and thinkers into low-level entertainers”, and they last 15 minutes. Given the current enthusiasm for brevity, make sure the selected format is appropriate for the content presented.