[mattetti]

@cscotta as the author of the blog post, I can only agree with the concerns you raised and thank you for your kind words.

Concurrency is something both Ruby and Python have to take seriously pretty quickly if both communities want to mature and play a more important role in the coming years. As you pointed out, there are different ways to get some sort of concurrency and they all present challenges and tradeoffs while none will cure all ills. But at the end of the day what matters is a community of people embracing these approaches and pushing the language further.

By removing the Global Interpreter Lock most of the alternative Ruby implementations are making a statement and the community seems to react. If we educate the community, commonly used code will become threadsafe over time and developers will learn what it means to write threadsafe code. If made easy, co-routines and non-blocking IO will be used. If implemented well and properly explained, actors will be used more often when it makes sense to do so.

My goal was to try to simplify the concurrency problem so the community as a whole can discuss the topic. I think that the concurrency challenge can be improved by increasing the awareness, getting people motivated and having an open discussion. There is a reason why Ruby and Python still have a GIL and why removing it to improve concurrency would have its downside. I want to make sure people understand that before blaming Matz for not removing the GIL already. The Ruby implementation fragmentation also hurts progress done in MRI, if you look at it, alternative implementations often have more people working on them than people working on MRI!

Let's hope that this article is indeed a step in the right direction.

[cscotta]

Absolutely - thanks, Matt. This is a very well-written, thorough article, and it provides a clear, thoughtful survey of the landscape for folks who are interested in parallelizing their programs and learning more about the advantages and tradeoffs implicit in different approaches. This piece has a lot of potential to catalyze thought within the community about how best to move forward.

The explosion of interest in the subject intrigues me. The work that's been going on in terms of making mainstream Ruby libraries threadsafe is great to see, along with fibers and evented approaches. MacRuby's exposure of Grand Central is especially unique. But interest and upvotes must also be followed by action. There will be a lot of false starts. We'll probably see a handful of approaches which bloom and fade from popularity. While the "fragmentation" issue is there, I tend to think of it in terms of spirited experimentation. In any case, people really care now, and it's that drive that forces a community forward. That's good to see.

Keep it up!