This new status update attempts to summarize my professional activity for June. That's another month where I didn't accomplish much beyond administrative tasks, which are utterly important but not very interesting, TBH. That's frustrating, since June is usually the month where I can unleash my imagination on funny research ideas. But not this year: I was swamped elsewhere. I also lost significant amount of energy being overwhelmed by the news. The growing rise of the far right is stunning, and it's not easy to live our lives in such setting. Anyway. Here is the summary of my professional activity this month.

If you lack context, look at the bottom of this page for an introduction to the cited projects, or refer to previous similar reports: January 2024, February, March, April, May, (June).

On the teaching front, I reviewed and updated the material of my C++ class, learning from this term. That's a very pleasing activity since I finally got the opportunity to check a few points about which I was not sure. I hope that next year's be better than the last one, which left me a bit frustrated because of the rush which hindered my preparation. That's maybe my most pleasant achievement this month.

On the unplugged activities' front, I had the chance to spend one afternoon with Tim Bell, to co-founder of the CS unplugged initiative since he was in Rennes for personnal reason to visit a friend of both of us. The discussion was fruitful, even if it's a bit shameful to admit the amount of good resources that we keep on our side by not translating them to english. Also, my material is very messy and I really should take the time to (re)organize it. I did not even merge the feedback of my students to the activities yet. Shame shame.

The administrative front was quite a nightmare, to be honnest. ENS Lyon drafted one of our teachers, and they did so very late in the year. We were almost done with the setup of next year when it happened, and we had to reshuffle all responsabilities plus some teachings. Indeed, we are only 5 permanent faculties in my institution (now only 4) while over 50 people take part to our 4-years long curriculum. So that's quite a lot to organize and we must all take responsabilities. Next year, I'll be both chair of this teaching department and associate chair since I'll be in charge of the first year of our curriculum in addition to the department overview. We managed to staff almost all classes for the next year but I still have a few emails to do for the statistic class.

We also had to organize all the juries in a rush, since the other reorgs got us short on schedule. Dealing with such important topics on short time is always very difficult and unpleasant. But that's hopefuly done for this year, now.

Not much happened on the Mc SimGrid front. Mathieu merged his code to find the critical transition of a given failure in the git. I'm supposed to review this code and maybe clean it a bit, but it did not happen yet. We will hopefuly work on a paper next month, but the time is ticking before the summer vacation. Nothing happened on the regular SimGrid this month, nor on the TANSIV front. Léo was busy giving presentations and somewhat swamped into administrative tasks.

On the SmolPhone front, Israël did a great work characterizing the power consumption of our 4G LTE modem. The results are not easy to summarize, with 5 power levels and 8 usage scenarios, but the numbers we get are really interesting in the context of our project. Building a low power smartphone around a 4G Cat1 modem really seems doable.

As expected, Aloïs presented his poster at the 'ICT for sustainability' conference this month, and he got very interesting feedback. There were very good papers at this conference, and I was particularly interested in this one, which uses the research and theories of Hartmut Rosa to counter the tendency to change working devices because of the advertisement pressure. Really interesting.

We had promising applications to our open position for a software engineer. The interviews should start soon, even if the position is only to start in October. Unfortunately, we have no application to the hardware engineer position so far. We still have time, and I really hope that we'll manage to constitute a great team for next year. Please apply!

On the frugal computing front, I checked a bit on the Odin language, but nothing serious so far. It really seems to be a nice little language, but could not find the time and energy to experiment with it properly.

On the open-source front, I packaged the latest versions of the widelands game and of the ns-3 network simulator. Widelands was not trivial, since this new version induced a build failure on big endian systems. I was lucky since upstream developers were very reactive to fix this issue, and could enjoy the pleasure of successful open-source cooperations.

I also fixed the FTBFS errors (fail to build from source) induced by the latest version of po4a in Debian. There was two issues, one of them linked to the fact that some users are using private API of po4a so they need to update their usage now that I changed one parameter from optionnal to mandatory. The second one is linked to the fact that po4a is now much less forgiving about encoding. If your files are not UTF-8 (as in this case), you have to say so in the configuration. I updated the doc for both issues, hopefully helping users to correctly use po4a. No other issue were reported since the a few weeks, so it should be OK now.

Finally, I was asked to update the package of the Frogatto game, which version 4 was released recently, a few years after the v1.3 that is already in Debian. But I did not find the time to investigate yet.

Context: The projects I'm working on these days

SimGrid is a simulator of distributed systems developed by a team of friends since 2000. It takes a distributed application (written in C++/C/Python using our dedicated APIs or in C/Fortran using the MPI standard), and it executes the application on a fast but realistic network simulation. It provides timing and energy consumption forecasts, allowing one to prototype, study or profile distributed systems in a wide range of settings, Over the years, it grounded the experimental sections of 630 scientific articles around the globe. This paper gives a somewhat outdated overview of the framework, but the replacement is still under review.

Mc SimGrid is a software model checker (SMC) embedded in the SimGrid framework. It exhaustively tests the applications that can run on top of SimGrid, exploring all possible orders of events to find bugs that only occur after a specific sequence of events. In some sense, it's related to fuzzing that tries to feed the application with random data to find bugs, but instead it exhaustively "randomizes" the events' scheduler. More info in this paper. That's the context of Mathieu Laurent's PhD thesis, co-advised with Thierry Jéron. We work on improving Mc SimGrid to eventually make it a widely usable tool. To that extend, we first aim at finding a wild bug, i.e. a bug that exists out there in an application rather than a synthetic bug that we add to test our tools.

TANSIV is a contraption interconnecting virtual machines with a simulated network to study arbitrary applications. The key difficulty is to synchronize the time of the virtual machines with the simulated one. The first challenge is to precisely pause and restart virtual machines, which is easy in the slow emulated mode but much harder in the fast hardware-accelerated mode. The second challenge is that the simulated time is discrete, but the wall clock of the VMs is naturally continuous. This is the PhD topic of Léo Cosseron, co-advised with Louis Rilling. More details are given in this paper.

SmolPhone is an action research on digital sufficiency as defined in this article. Other relevant keywords are low-tech and empowerment in IT systems. Its practical aspects consist in designing a sort of long-lasting smartphone. The goal is not to optimize a typical smartphone but rather to explore unusual hardware & software architectures. I take this as a journey to reconsider the way we design computing systems. Some more details are given in this short paper. Aloïs Rautureau was a master student working co-advised with Simon Rokicki and Joseph Paturel. Israël Kafando is an ENSSAT student, co-advised with Simon, Joseph and Mickaël Le Gentil.

po4a is a free software to ease the maintenance of documentation's translation. It makes it it easy to track the modified parts in the original documents so that translators can update their work when the documentation changes. Largely adopted by the community, it is now a key component of several renowned open source projects including Debian and F-droid. This project is on slow development/maintenance-only mode these days. I try to keep up with the request of the community, but I really need the help of the existing power users to be somewhat reactive.