Category Archives: SAoC

DMD 2.088.0 Released

Digital Mars logoThe newest DMD has rolled off the assembly line and is ready for download. A total of 58 contributors fixed 58 bugs and introduced 27 major changes to version 2.088.0 of the compiler.

I’m always looking for the big ticket items in a new DMD release to highlight on the blog, but this is a workaday release that isn’t showing off anything too shiny in the changleog. Much of it is run-of-the mill maintenance: deprecations, removals, and behavior adjustments. All of that is important, and we all welcome it, but it doesn’t make for great reading on the blog. That said, there are a handful of useful additions that I can point to, one of which actually is a big deal when it comes to C++ interop.

std::string and std::vector

Thanks to the work Manu Evans has been performing and advocating, C++ interoperability gets a big boost in this release with bindings to std::string and std::vector in the DRuntime modules core.stdcpp.string and core.stdcpp.vector, respectively.  There’s one caveat with the std::string binding that anyone intending to use it must be aware of.

When compiling on Linux, where DMD makes use of the GCC libraries and linker, there’s a compatibility issue when using the modern version of std::string which is compliant with C++11. It contains an interior pointer, which in D is both illegal and incompatible with move semantics. The work around is to pass -D_GLIBCXX_USE_CXX11_ABI=0 to g++ and compile your D application with -version=_GLIBCXX_USE_CXX98_ABI. This will be resolved in the future when work on move constructors in D is complete.

New Utilities

The language gets an interesting new compile-time trait in the form of getLocation. Given a symbol, this trait will return a tuple containing the file name, line number, and column number at which the symbol appears in the source code. This opens the door to more informative debug logging and error reporting beyond the functionality already available via __FILE__ and __LINE__. And I’m sure folks will find other uses for it.

The standard library utility module std.file, which provides a lot of convenience functions for working with files as a unit, now has the new function getAvailableDiskSpace. Give it a directory path on Windows, or the path to a directory or file on Posix, and it will give you the number of bytes available on that path.

Other News

The Symmetry Autumn of Code 2019 participants all have mentors now and they are hard at work laying out their milestones. Milestone 1 officially kicks off on September 15, after which we can expect to see weekly updates from the participants in the General forum.

Google Summer of Code 2019 has come to an end. Five of our students submitted their work at the end of August. You can find information about their projects and view their code submissions from our GSOC projects page. Congratulations to all who participated!

The D Language Foundation is currently in discussions to put some of the Human Resource Fund to use in finalizing LDC support for iOS and Android. Hopefully, I’ll have details to report on that front in the very near future. In the meantime, please help us raise the HR Fund even higher than it is now. There’s some important work waiting to be done that will require as much money as we can throw at it. You can donate any amount directly to the HR Fund Campaign or use the special campaign we set up to send $60 to the HR Fund and get a DConf 2019 t-shirt in return.

Speaking of t-shirts, thanks to everyone who has made a purchase in our DLang Swag Emporium. You’ve helped us raise over $77 so far, all of which will go to the General Fund. If you haven’t yet dropped in, what are you waiting for? We’ve got t-shirts, stickers, and coffee mugs, with updates coming soon. It’s an easy way to support our favorite programming language!

 

SAOC 2019 Projects and Participants

Symmetry Investments logoLast Sunday, August 18, was the deadline for Symmetry Autumn of Code 2019 applications. We received a total of eight applications, which is the same number we saw last year. This time around we were able to accept more than three: five of the applicants will be participating.

The applications were reviewed by the five members of the SAOC 2019 Committee. Each member independently ranked the applications in order of preference. Points were assigned based on the rankings and the top five applications were accepted.

Before we get into the details of the projects, on behalf of the D Language Foundation and the SAOC team, I’d like to publicly thank all eight applicants for taking the time to submit an application. I’d also like to thank Laeeth Isharc and Symmetry Investments for sponsoring the event again this year, and our five SAOC Committee members for volunteering their time throughout the event:  John Colvin, Mathias Lang, Átila Neves,  Robert Schadek, and Ethan Watson. They will be monitoring the progress of each project through the milestone reports and ultimately will select one participant to receive an extra $1000 payment and an all-expense paid trip to DConf 2020.

The Projects

  • Multi-Level Intermediate Representation Support for LDC – According to the MLIR project README, it’s “a common intermediate representation” intended to “unify the infrastructure required to execute high performance machine learning models in TensorFlow and similar ML frameworks”. Roberto Rosmaninho’s primary project goal is to provide the LDC D compiler with “a new level of abstraction to support the integration of MLIR into the D ecosystem”. Roberto is working on a Computer Science major and is an undergraduate research assistant at Federal University of Minas Gerais in Brazil. His mentor for the project is Nicholas Wilson.
  • Implement DIP 1014 and expand support for C++ STL containers – Suleyman Sahmi’s main goal is to “advance the existing work on [the] D interface to C++ STL containers”. There is a project at GitHub geared toward that end which Manu Evans and Laeeth Isharc have been working on and which is blocked on the lack of an implementation for DIP 1014, along with a few issues with the D ABI and name mangling. He first intends to implement DIP 1014, then he’ll resolve several of the related DMD bugs and will use the remaining time to expand support for the C++ STL. Suleyman is a self-taught programmer from Morocco and already has become a contributor to DMD.
  • DPP with Linux kernel headers – The DPP tool, which allows D modules to directly #include C and C++ headers, currently is unable to work with the Linux kernel headers. Cristian Becerescu aims to fix that. If he is able to do so with time remaining, he will work on further improvements and refinements to DPP, including ironing out issues it might have with other C library headers the community brings to his attention. Cristian is a 4th-year Computer Science and Engineering student at University Politehnica of Bucharest. He is fortunate to have two mentors for this project in the form of Edi Staniloiu and Razvan Nitu.
  • Create a CI or other infrastructure for measuring D’s progress and performance – Max Haughton, an 18-year-old British physics student, will be taking on the task of “creating a mechanism by which we can measure various properties of the D ecosystem in a deterministic manner”. This includes properties such as compilation time, compile-time memory usage, and profiling the compiler to determine “why performance is what it is”. He also intends to extend it to run-time performance by “forming a set of benchmarks by which we can profile Phobos and druntime both against their versions…and the version of the compiler”.
  • Solve Dependency Hell: link with more than one version of the same project – When a project has dependencies that in turn rely on different versions of the same library, steps must be taken to reconcile the version difference in order to successfully compile. If it’s even possible, it’s cumbersome and introduces new difficulties. Tiberiu Lepadatu aims to solve this problem of Dependency Hell by making it possible to compile a project with multiple versions of the same library. This is considered as a crucial first step in making Phobos available via the DUB registry. Tiberiu is no stranger to D and has contributed to the core projects in the past. He will likely be working with Sebastian Wilzbach as his mentor.

Getting Under Way

The SAOC participants will spend the next three weeks preparing to get their projects started. They’ll be compiling their Milestones, doing research, and those without a mentor will be searching for one. Things officially kick off on September 15, with Milestone deadlines falling on the 15th of each month through January.

This year, we’ll be expecting the participants to make weekly updates in the forums. We will also encourage them to spend time on IRC, Slack, or Discourse to get to know the community, discuss their projects, and find inspiration in solving the challenges they’ll face. We encourage all members of the D community to show their support and help keep up motivation.

Each of these projects will improve the D ecosystem.We’re fortunate to have this opportunity, along with out participation in the currently ongoing Google Summer of Code, to get so much done without the need to raise more money or dig into our Human Resource Fund. We should all be willing to do what we can to help these projects succeed.

On a personal level, I’m looking forward to working with these five programmers in the coming months and to seeing all of them make it through to the end of a successful Symmetry Autumn of Code!

 

Symmetry Autumn of Code Experience Report: Porting a fork-based GC

Symmetry Investments logoThe 2018 edition of the Symmetry Autumn of Code was a wonderful opportunity for me and two other students to dive into an interesting programming challenge and contribute to the D community. I am going to describe the process that led to my participation in SAOC and what this four months of work meant to me.

Who I am

I am an MSc student in Computer Science at the University of Turin in Italy. My interests mainly revolve around type systems, language theory, formal languages and compilers, and concurrent programming techniques. I am 23 years old and I have been programming since I was 20.

What happened before SAOC

While browsing Hacker News one day, one comment caught my attention: “the [D] community seems second to none as far as signal to noise ratio goes”. From that day I started lurking on the D forums and later read Andrei Alexandrescu’s book, The D Programming Language. While I think it alone wasn’t sufficient to learn the language, it was worth the read for all the discussions about compiler internals, the compromises about the syntax, and the details on ranges and concurrency by message passing.

After reading the book, I had enough confidence to start exploring some real-world code and I decided to dig into the codebases of the D standard library (Phobos) and vibe.d, a popular web app framework. My colleague Francesco Gallà, who also would participate in SAOC (see his DConf 2019 presentation about his experience), started learning D and we approached the community together by discussing one of the past Google Summer of Code proposals, HTTP2 support, on the vibe.d forum.

At the same time, I bought the Garbage Collection Handbook as a personal reading. At the time it seemed totally unrelated to what I was doing with D.

SAOC

On July 14, 2018, the D Language Foundation announced the Symmetry Autumn of Code. It seemed the right occasion to boost my skills with D and get even more involved with the community. I was also thrilled by the possibility of learning new methodologies for writing code with a remote mentor.

I gathered information about a past project, a concurrent garbage collector that was used in D1 in the Tango library. I decided that my SAOC project proposal would be to port it to D2 with the goal of incorporating it into the D runtime.

The original work was done by Leandro Lucarella as his master thesis, and he documented it extensively on his blog. I contacted him and received confirmation that he could mentor such a project. After that, I wrote my proposal. It consisted of two documents, one about me and the other about the project.

The concurrent GC project

The project document had the objective of showing my efforts in understanding the garbage collector currently shipping with the D runtime—a conservative mark and sweep GC that does the following whenever an allocation is issued and memory needs to be reclaimed:

  1. stop all threads except the current one
  2. “hijack” the work of the current thread in order to run the GC routines
  3. start scanning recursively every root memory pointer in order to find every memory block that has been used or is being used by the program
  4. mark all GC-allocated blocks that are no longer referenced
  5. resume all other threads
  6. run destructors from unreachable memory that has been marked in phase 4 and free the remaining unreachable memory
  7. continue execution of the current thread.

The program is paused during steps 1 to 4 (the mark phase) and memory is reclaimed during step 6, where the GC thread hijacks the flow of the thread that triggered the collection. There are various approaches for reducing the pause time, such as using threads to scan and mark the memory objects in parallel; work is being done in that direction.

My proposal highlighted another strategy. By sacrificing memory consumption on systems that support Posix’s fork() system call, pause time could be drastically reduced. A fork-based concurrent GC would be represented by the following sequence of routines:

  1. a thread triggers the GC collection (such a thread is called the mutator)
  2. the GC clones the address space of the current program with the fork() system call
  3. while the parent process continues execution, the child process starts the mark phase
  4. at the end of the mark phase, before exiting, the child process communicates the marked bits (that can be reused) to the parent
  5. the GC uses the unmarked blocks for future allocations (lazy sweep).

With this schema, the pause time of the marking phase is reduced to the duration of the fork() call only. There are many advantages, such as the fact that the other threads do not need to be stopped and that the reclaim phase could run concurrently without hijacking the mutator. In particular, this strategy shows its strength in potentially long-running programs that have large heaps with a high number of live objects.

The implementation resulted in a bit more than 500 lines of code, given that the calling process (called the parent) generates a duplicate of itself in a different address space. This removes the need for synchronization, which has a high overhead both in terms of runtime performance and code implementation. Moreover, Unix and Linux systems provide very efficient fork() implementations with the use of COW memory.

Methodologies

The first thing that I did with Leandro was to correct the milestones that I had predicted. Based on his experience, we put a bigger focus on defining the tests rather than the programming. After that he specified the workflow to me. We setup a test suite in place, mainly composed of dustmite, the runtime benchmarks and tests, and some D1 programs that I ported.

After discussing and applying every change to the codebase in a different branch, I had to run the tests and then open a pull request on my GitHub repository asking for a review from Leandro. Commits had to be very granular and he always provided a lot of feedback. He was always prompt in replying and we had a number of exchanges by email before applying a change. Many times we discussed benchmarks and regressions, and sometimes I asked for help with debugging. I can confidently say that I spent more time researching, reading, debugging, and discussing code than I spent writing it.

I was alone in managing my time and my commitment. Leandro and the D Foundation were always present in discussing things by email, but they didn’t force any time sheet on me nor did they micromanage my work.

The end of SAOC

At the end of the four months of SAOC, I had a working implementation, but I decided to delay a pull request to the D runtime in order to work on some profiling code that could help developers understand in which cases the fork-based garbage collector brings advantages. After a precise garbage collector was announced for DMD 2.085.0, I decided to adapt my work to it. It was very straightforward given the clarity of the added code and the separation of concerns in place.

Leandro was available for mentoring even after SAOC. We exchanged many emails and he showed me how the D garbage collector is being profiled at Sociomantic.

The pull request

A pull request to the D runtime was my final milestone. I was ready at the beginning of February, but I started to procrastinate. I’d had no previous communication with any of the reviewers and I was timorous about engaging with them. I spent a lot of time refactoring my code back and forth and delaying my pull request. At a certain point, I even considered abandoning the final milestone and providing the GC as a library. In the meantime, Rainer Scheutze published a threaded implementation of the mark phase that reduced the mark time in the GC and I lost faith in my project.

Luckily for me, I had the opportunity to attend DConf 2019 in London. There I found many great people who talked with me and convinced to resume my work. I had a brief discussion with Rainer and I started testing against his implementation (I also found a related bug in the CPU detection code) and on the last day, during the annual Hackathon, I finally opened the pull request.

Since May 11, I have discussed changes to my code, reduced the number of lines of code, refactored and collapsed some functions, and resolved bugs related to program termination. The pull request is still open given that there were many rough edges, but overall I am very satisfied about the feedback received and with the whole process. Reviewers responded to every commit and provided guidance when needed. Whenever something wasn’t clear, I replied on GitHub or asked for help in the #D IRC on freenode.net.

In retrospect, I should have opened the PR much earlier and presented the reviewers with every doubt that I had along the path.

Experience analysis

SAOC helped me in understanding the dynamics behind contributing to a community project such as D. I was already spending a fixed amount of time reading the forum every day and I started to direct some of that effort to GitHub. Checking pull requests, commits, and issues was expensive work, but it was necessary to gain knowledge about the methodologies regarding the development of Phobos and the runtime.

I also learned that there are many changes that go unnoticed if you don’t closely follow the discussions on the PR queue. One example is Manu Evans’s work on core.stdcpp that is very difficult to follow when it’s scattered across different forum threads and lacks a proper announcement.

I think that overall, communication was a weak point of my experience. Regarding SAOC, we defined the work in detail but we didn’t put any effort on communicating the status of my work to the community. That could have triggered helpful suggestions from the community that could have helped me to discover holes in my implementation. Again, I benefited from this great amount of freedom in managing my work, but I think it could have coexisted with some effort on communicating more.

Finally, I had previously used D for higher level code, but SAOC forced me to discover D from a new angle; I dived into low-level code. I was amazed by the flexibility of the language and found myself becoming familiar with this different style of writing code very quickly.

Conclusion

The Symmetry Autumn of Code was a very rewarding experience. It was a period of discovery, self-growth, and involvement in a new community.

I am very grateful to Symmetry Investments and the D Language Foundation for this opportunity. Moreover, I want to thank my mentor, Leandro, for all of his help and for all the positive exchanges that we had.

Get Ready for Symmetry Autumn of Code 2019

Symmetry Investments logoLast year, Symmetry Investments sponsored three programmers to work on projects in the D community. Two completed successfully. Francesco Gallà worked on adding support for HTTP/2 to vibe.d and got the grand prize of a bonus payment and a free trip to DConf 2019, where he gave a talk about the experience and his project. His compatriot, Franceso Mecca, worked on porting an old D1 forking GC to D2 for integration into DRuntime. He has a blog post drafted on that already that I will publish here as soon as he finishes the next round of work on the project and updates the draft with some new data.

Now, on behalf of the D Language Foundation and Symmetry Investments, I’m happy to announce that we are go for Symmetry Autumn of Code 2019! You’ll find the details on the SAoC page here at the blog.

This year it’s the same but different! It’s open once again to any programmer, with a preference for students. Participants will receive $1000 USD for each of three successful milestones for a total of $3000. One participant will be selected for a final $1000 payment and a free trip to DConf 2020.

Thanks to feedback from last year’s participants, we’ve made some adjustments this time around. The most visible is that we’re allowing more time to ramp up the projects. Officially, the project planning phase begins September 1, but realistically it begins a week earlier when the applicants are notified of their application status. The official launch of SAoC 2019 is on September 15, two weeks later than last year. We’ll also require participants to submit weekly status updates to the forums this year to encourage more interaction with the community.

Behind the scenes, we’ll be a little more hands on this year in the areas where it matters. The participants last year were happy that we weren’t looking over their shoulders, but there were areas where they would have found our intrusion be a boon. So this year, we’ll be taking a more active role in helping participants find mentors and ramp up their projects, and we’ll communicate more frequently with each student to determine any other specific support we can provide. We’ll stay out of their code and their workflow–that’s what mentors are for–but we’ll do what we can to help ensure a successful project for each participant.

We’re also doing something different for the mentors this year. The SAoC 2018 mentors received the gratitude of the participants and the organizers, and nothing else. Mentors in SAoC 2019 will get all that gratitude, but they’ll also each receive a one-time payment of $500 at the end of the event for a successful project. If, for whatever reason, a participant is unable to complete the event, the mentor may still be eligible for the payment, but it will have to be evaluated on a case-by-case basis.

Following in the tradition of the Google Summer of Code events we’ve participated in over the years, we used a Wiki page for SAoC 2018 project ideas. This year, we’re using the new dlang/projects repository. Anyone with an idea for a SAoC project is welcome to submit an issue there. We’ll tag suitable projects with a SAOC tag so that SAoC 2019 applicants can easily search for projects that interest them. Please read the SAoC page for some guidelines on the sort of information a good project idea should contain.

We’re looking forward to seeing the applications this year. We’d like to expand the number of participants from last year’s three, but that depends on how many applications we get.

If you are interested in participating, please start thinking about your project ideas! The more detailed your application, the better the odds of being selected. We’ll get the tags going on dlang/projects soon to help get the gears cranking.

For the rest of you, please submit project ideas or consider being a mentor. Potential mentors should either contact me directly or announce their interest in the forums. Applicants in search of a mentor can do the same. The details are on the SAoC 2019 page.

Good luck!

DConf 2019 Early-Bird Registration Opens (and Other News)

I’ve got a few big news items for you today, the biggest being one I’ve been eagerly awaiting: early-bird registration for DConf 2019 London is now open!

Early-bird Registrations…

…are now open!

We’re very fortunate, thanks to the generosity of Symmetry Investments, to be able to keep the normal registration fee to our standard $400 this year. Like last year, the early-bird discount is once again 15%, so register before March 17, 24:00 AOE, and you’ll only pay $340. Unfortunately, unlike past editions of DConf, we’re required to charge a VAT of 20% this year, so the early-bird rate with tax is $408 and the regular registration will be $480 with tax. The GBP value of the VAT is listed alongside the price on the registration page and will be updated when the average monthly exchange rate changes.

Currently, you’ll find two options for payment on the registration page: Flipcause and PayPal. Those of you who have been following the latest goings on will know that we’re using Flipcause to create donation campaigns. They also provide support to configure campaigns for events like DConf, allowing us to keep as much as possible coming into one place. In the long run, this will be more efficient for us than accepting money through other services, so if you aren’t paying with a PayPal balance for your DConf registration, we ask that you please choose the Flipcause option.

You’ll also find the DConf campaign listed in our Campaign Menu, which is accessible from the big Donate Now button in this blog’s sidebar as well as from the D Language Foundation’s donation page. In the past, we have supported Eventbrite as a payment option, but have not yet decided if we will do so this year.

Invited Keynote Speaker

I’m also happy to announce that Laeeth Isharc has accepted our invitation to be a keynote speaker at DConf 2019.

Every year, Walter and Andrei are joined by an invited keynote speaker to open each of the three presentation days of the conference. Sometimes, the speaker is from outside of the D community for a different perspective (Scott Meyers was the invited keynote speaker at DConfs 2014 and 2017, and Martin Odersky was the invited keynote speaker last year). This year, offering the invitation to Laeeth was a no-brainer.

Not only is Laeeth responsible for bringing DConf 2019 to London under the sponsorship of Symmetry Investments, he’s also an enthusiastic supporter of the D programming language. He hires D programmers, sponsors open-source D projects, initiated the Symmetry Autumn of Code (SAoC), and can be found in various forums around the internet answering questions about D. Despite all of that, he’s never spoken at a DConf. We can’t wait to hear what he has to say!

The SAoC Finalist

Three programmers started the Symmetry Autumn of Code. Each participant was to complete three milestones, each of one-month duration, and would receive $1000 upon the successful completion of each. After a final month of clean-up work (whatever was required by each project), one participant was to be selected for a final $1000 payment and a free pass to DConf 2019, including travel and lodging.

One participant was unable to continue after the first milestone. The other two—Francesco Mecca, whose project was porting Leandro Lucarella’s old D1 forking GC to DRuntime, and Francesco Galla, whose project was adding HTTP/2 support to vibe-http—were able to see the event through to the end. Both did some excellent work on their chosen projects, but only one would be selected for the final prize.

I can now announce that congratulations are in order for Francesco Galla! He’ll be receiving the final payment and the trip to DConf 2019. As it turns out, he and the other Francesco happen to be friends. They had an agreement beforehand that the finalist would use the extra $1000 to pay for the other to attend DConf. And we’ve been informed that we’ll be fortunate enough to meet both of them in London!

We’ll also be hearing from Francesco Mecca before then, as he has agreed to write about his project for this blog. Francesco Galla will either write a blog post or, depending on how the conference schedule comes together, give a presentation about his project at DConf (possibly both!). Keep an ear open for the announcements.

The New Fundraiser

The PR Manager Campaign was a tremendous success. Not only did we meet our goal well before the deadline, but Nicholas Wilson has done a great job cleaning up the pull request queues. We will continue that campaign for another quarter, starting next month.

In the meantime, we’re raising $2000 for a new server for the D Forums. There are two reasons we’ve selected this as our next target.

First, Vladimir Panteleev has been paying for the server for the D Forums (and his other D services) out of his pocket for years. It’s time we put a stop to that. The forums are a crucial part of the D programming language community and it shouldn’t be up to one person to pay the bills.

Second, the forums have been experiencing performance issues at an increasing frequency over the past several months. Among the possible solutions that Vladimir has identified to improve this state of things, moving to better hardware is a big one. If ever there was a time for the community to take over the server bills, it’s now.

So we encourage you to donate to the cause! Helping us meet our $2000 goal will cover a new server for the forums and provide a cushion for any incidental expenses. Vladimir has graciously declined to accept any money from the D Language Foundation for the work he does in actually maintaining and improving the forums, so we’d like to draw your attention to his Patreon account, where you can more broadly support the open-source work he does.

We thank Vladimir for all the time and money he’s put into this over the years, and thank you in advance for your donations!

Updates in D Land

As we encroach upon the end of 2018, a recent Reddit thread wishing D a happy 17th birthday reminded me how far the language has come since I first stumbled upon it in 2003. Many of the steps along the way were powered by the energy of users who had little incentive to contribute beyond personal interest. And here we are, all these years later, still moving forward.

There are a number of current and upcoming happenings that will play a role in keeping that progress going. In this post, I’d like to remind you, update you, or inform you about some of them.

The Pull Request Manager Campaign

If you haven’t heard, the D Language Foundation has hired a pull request manager, to be paid out of a pool of donations. This is our first major fundraising campaign through Flipcause. I’m happy to report that it’s going well. As I write, we’ve raised $1,864 of our $3,000 target in 66 days thanks to the kindness of 30 supporters. If you’d like to support us in this cause, click on the campaign card.

You can access our full campaign menu at any time via the “Donate Now” button in the sidebar here on the blog. A pull request has also been submitted to integrate the menu into dlang.org’s donation page. Currently, we only have two campaigns (this one and the General Fund) but any future campaigns will be accessible through those menus.

Symmetry Autumn of Code

Earlier this year, Symmetry Investments partnered with the D Language Foundation to sponsor the Symmetry Autumn of Code (SAoC). Three participants were selected to work on D-related projects over the course of four months, with milestones to mark their progress. If you haven’t heard of it or had forgotten, you can read the details on the SAoC page here at the blog.

Unfortunately, one participant was unable to continue after the first milestone. The other two, whom we have come to refer to as the two Francescos, have each successfully completed three milestones and are in the home stretch, aiming for that final payment and free trip to DConf 2019.

Francesco Mecca is working on porting an old D1 GC to modern D, and Francesco Galla’ is busy adding HTTP/2 support the vibe-http library. Both have made significant progress and are on track to a successful SAoC. Read more about their projects in my previous SAoC update.

DIP Updates

I’ve received partial feedback on a decision regarding DIP 1013 (The Deprecation Process) and expect to hear the final verdict soon. As soon as I do, I’ll move Manu’s DIP 1016 (ref T accepts r-values) into the Formal Assessment stage for Walter and Andrei to consider.

I had intended to move Razvan’s Copy Constructor DIP into Community Review by now, as that is a high priority for Walter and Andrei. However, he’s been working out some more details so it’s not quite yet ready. So as not to hold up the process any longer, I’ll be starting Community Review for one of the other DIPs in the PR queue at the end of this week. When the Copy Constructor DIP is ready, I’ll run its review in parallel.

Google Summer of Code (GSoC) 2019

At the end of last month, I announced in the forums that we’re ramping up for GSoC 2019. I seeded our Wiki page with two potential project ideas to get us started. So far, only one additional idea has been added and no one has contacted me about participating as a student or a mentor.

It’s been a while since we were last accepted into GSoC and we’d very much like to get into it this time. To do so, we need more project ideas, students to execute them, and mentors to provide guidance to the students. If you’re looking for another way to contribute to the D community, this is a great way to do so. Adding project ideas costs little beyond the time it takes to add the details to the Wiki and, if you are lacking in ideas already dying to escape the confines of your neurocranium, the time it takes to brainstorm something. Student and mentor participation is a more significant commitment, but it’s also a lot more rewarding. If you’re interested, tell me at aldacron@gmail.com.

DConf 2019

Finally, I’m happy to announce… Just kidding. I can’t announce anything yet about DConf 2019, but I hope to be able to soon. What I can say with certainty is that in 2019, DConf will be where DConf has never gone before. We’re currently working out some details with an eye toward making 2019 a big year for DConf.

I’m really excited about it and eager to let everyone know. I’ll do so as soon as I’m able. Watch this space!

Symmetry Autumn of Code is Underway

Earlier this year, Laeeth Isharc brought an idea to the D Foundation for Symmetry Investments to sponsor a summer of code. He was eager to provide a few motivated individuals the incentive to get some great work done for D and the D community. Sporadic email discussions preceded some chatting at DConf 2018 Munich and the idea subsequently began to pick up steam. By the time the details were sketched out, it had transformed into the Symmetry Autumn of Code.

The SAoC projects

Eight applicants submitted their resumes and project proposals for three slots. Nearly all of the proposals were taken from the SAoC suggestions page at the D Wiki. Given the limited window, the selection process went fairly quick. Of the three selected, two had mentors attached. It took a little while to find a mentor for the third selection, so we extended the milestone deadline for that participant. Now I can happily say that all three are well underway.

A fork-based concurrent GC for DRuntime

Francesco Mecca proposed this project. The goal is to take Leandro Lucarella’s original D1 fork-based GC, port it to D2, adapt it to DRuntime’s GC interface, and culminate with a pull request for DRuntime to present the work and open discussion. Leandro agreed to mentor this project and is working with Francesco to develop a test suite that the port must pass as part of Milestone 2. They have also included documentation in their milestone list, which is good news.

vibe.d HTTP/2 implementation

This one came from Francesco Galla, who is currently pursuing a MSc in Network and Security. The goal here is to enhance the vibe-http library to support HTTP/2. Fittingly, Sönke Ludwig, the maintainer of vibe.d, agreed to mentor the project, but requested someone to share the load due to his schedule. Sebastian Wilzbach stepped up as co-mentor.

This project involves rewriting the current HTTP/1 API, ensuring it works as expected, then incrementally adding support for HTTP/2. Portions of the rewrite were already completed before SAoC came along, but had not yet been tested. As such, testing and bug fixing will be a significant portion of the first milestone.

Porting the Mago debugger to D

This project was proposed by László Szerémi. He’s a heavy user of debuggers in D and wants to see the situation improved. He believes that porting the Mago debugger to D is a major step in that direction. His first two milestones are concerned with translating, testing, and bug fixing. To cap off the SAoC event, he intends to get a GUI frontend up and running with some basic features.

László had no mentor when he applied, and no one had specifically volunteered to mentor any debugger projects, so we put out a call in the forums and I reached out directly to a few people. In the end, Stefan Koch agreed to take it on.

SAoC is not the end

I know that one of the goals Laeeth had behind his initial suggestion for this event was to enhance the D ecosystem. None of the selected projects are simple, one-shot tasks. These are projects which will all require attention, care, and effort beyond SAoC. The participants are getting them started and we hope they’ll continue to maintain them for some time to come, but in the end, these are projects for the community. When SAoC 2018 is behind us, it will ultimately be up to the community to determine if the projects live long and prosper or die young.

I’ll post more about SAoC and the participants as the event goes on. We wish them the best in meeting their milestones!