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Comment by pmoriarty | Hacker News Reader

"It cannot be understated, removing the GIL will be a HUGE deal for Python! It's an ugly wart which has existed for about 30 years, and nobody else has produced and delivered a working solution to the community."

If it's such a huge game changer why don't some of the large enterprises which rely on Python fund this work?

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Remember when it was discovered that arc welders could produce Carbon 60, and there was a huge run on arc welders? All of a sudden there was a whole new class of customer beyond the usual customer base of people who do welding: people who do materials science research.

I would hazard a guess to say that 99% of production Python is people doing the equivalent of welding, but there is also this 1% who want the GIL to be gone so they can repurpose Python as a tool for a whole new class of problem solving.

It will be an exciting future for them.

For us welders, we’ll carry on gluing stuff together blissfully unaware of the GIL. Async and non-blocking IO are great. I don’t think I’ve ever needed compute-concurrency, not in Python anyway.

Eh, even with true multithreading python will still be slow as molasses. If you want speed python will still not be your choice.

I'm not sure I fully buy this argument. I think programming languages are chosen for projects based on a number of different factors, speed being one of them, but developer productivity being another (and there are certainly many more). Given that there isn't usually going to be one language that is the best choice for every single factor, it seems pretty natural that some teams might pick Python due to productivity being more important but still have some need for better performance, and other teams might not be able to compromise on performance and have to resort to something like Java or Go or C++ but still would be able to iterate faster with something higher level. It's definitely not a given that there are enough potential projects that would get enough benefit from removing the GIL to make it worth it, but it seems silly to claim that anyone would would get any possible benefit from performance would never choose Python for other reasons.

There are enough choices that offer Python's productivity alongside JIT/AOT options, better supported from the community than PyPy.

As for the C, C++, Fortran libraries with Python bindings, any language with FFI can call into them as well.

I would say, Python's adoption while lacking performance is what is now building pressure to avoid specific Python communities to leave Python and migrate into one of those ecosystems in search of a better mix of productivity/performance, without being forced to use two languages.

Which other languages do you suggest?

Common Lisp, Scheme, Julia, Scala, Clojure, F#, OCaml

F# deserves its own category. You even get access to the .NET ecosystem for free. The developer experience is something else too.

Same applies to Common Lisp, Scheme, Scala and Clojure on the JVM/JavaScript platforms.

And Clojure also has a .NET implementation.

Ooh, a Clojure .NET implementation? This is news to me. From a quick look at the website, it looks really good... but how is it in practice? One of the major advantages of F Sharp's .NET integration is that it's developed by Microsoft, as of course they pretty much created the ecosystem from scratch.

It doesn't get that many public use cases, here's the biggest one I've seen: http://arcadia-unity.github.io/

But it is being continuously kept up to date by Cognitect, along with active development on a clojure-clr-next version. Maybe it has a bigger population of non public users.

Also: here's another implementation of Clojure on CLR, "Morgan And Grand Iron Clojure Compiler": https://github.com/nasser/magic (see also http://nas.sr/magic/) of which there's a great cmpiler implementation talk (at Clojure/North) somewhere on Youtube.

Performance is not binary. If you can be productive with Python and get closer to your performance goal, you get the best of both worlds. A lot of people who aren't primarily programmers don't have time to write everything in C++ (or keep up with development in that area). A more performant Python is a huge win for everybody.

Just like language choice isn't binary, there are plenty of options with Python like productivity, with much better performance, it isn't Python vs C++.

Not with a rich ecosystem like Python's.

Quality matters more than quantity, and in that regard there are enough options available.

This is a tire fire of a thread, it's clear there's lots of confusion about the tradeoffs.

This isn't a case of "x" or "y". There is literally nothing valuable about the GIL, it's an ugly hack of a vestigial appendage. Perhaps the reason I'm familiar with it is because the lack of elegant MP threading in Python perturbed me for years, until I was introduced to Golang.

Python devs generally don't want to use Java, JavaScript, etc. And the Go ecosystem is good but not as rich as Pythons.

Anyhow, take care pjmlp. Until our paths cross again I wish you all the best!

As long as the use cases one cares about are covered, the amount of additional packages are needless noise.

JavaScript, Java, .NET, C and C++ are where to look for, if you want to count package numbers, for AOT/JIT languages.

Some programming tasks are so trivial that processing speed is completely uninteresting.

Some are so compute heavy that massive amounts of time is put into tuning them (sort algorithms, fast-fourier transforms, etc).

Most fall somewhere on the spectrum between those extremes. If you can speed up your program by a factor of 20 by adding threads, Python can cover a bit more of that in-between spectrum.

If python can get a trivial 4x speedup by replacing a for loop with a threadpool.map, then that is worth it to many python programmers.

Just because python isn't the fastest language in the world, does not mean that making it easier / possible to write faster python is worthless.

a few years back I was curious so I took a self-balancing robot that I had written in C (it did PID in real time to set motors in response to the current angle).

I ported it to Python, with a totally naive simple single threaded loop. It worked perfectly. 25 updates a second, forever. No C code, except the interpreter doing its thing, and some GPIO code.

That's not slow as molasses.

From upthread:

> My page load time dropped from 77ms to 47ms when I ran some of the code in parallel.

I suspect some of us welders will also find some improvements here.

That's just a 2x speed increase.

More than 5x can be achieved with the GIL included (and has been promised, by the new Microsoft Python-speed-up initiative and that Python dev who made a similar proposal).

That Python dev (Mark Shannon) is part of the Microsoft team :-)

You may think you don’t need it but I suspect if you program larger than trivial python applications there comes a point where you do but you don’t even think about how the GIL is restricting you. Think about load time for example of something that does a bunch of work to initialise. Without the GIL it would be relatively trivial to speed up things that are independent, while with GIL you are usually out of luck because you can have either shared memory (e.g. previously loaded state) or concurrency but not both at the same time. From experience, trying to serialise and use multiprocessing is often eating up all the potential gains.

20-odd years ago, my team solved some performance issues in our desktop app by splitting a couple of tasks into their own threads on a computer with a single CPU. Being able to write threaded code is really useful.

I would love to parallelize a plugin script in Cura, the 3D print slicer. It does a bunch of embarrassingly parallel calculations, and could be made at least 16x faster for me. Because it's a plugin, though, it isn't pickle-able and multiprocessing doesn't work. I managed to make it work in a branch, but only on OSes that can fork processes. On windows, the plugin spawns multiple GUIs because importing the cura package apparently has the side effect of launching it...

If there wasn't the GIL, I could just create a thread pool and be done, and Cura could continue to be a delightful mess. :-)

> Remember when it was discovered that arc welders could produce Carbon 60, and there was a huge run on arc welders?

No, I don't, and can't find any writing about this at all, do you have any links? Because that sounds amazing

Here's the text of a patent describing the process. [0] Googling "fullerene" will get you more useful hits than C-60, so, e.g. "generating fullerene from arc welding."

[0] https://patents.google.com/patent/US5227038A/en

Bing found two URLs... Both to this page. Google found one -- also here -- and two ads.

This:

   generate fullerene "arc weld"

Worked a bit better in both. N.B: Quote marks only around the "arc weld" bit.

I believe the original paper on Buckminsterfullerine aka Bucky balls aka C60 described the approach. Basically do violent stuff with carbon and stick it in a mass spectrometer. The violent carbon bit is arc welding, because the arc welding tips are made of graphite.

Wikipedia informs me that the first papers used a laser (https://www.nature.com/articles/318162a0 - "graphite has been vaporized by laser irradiation, producing a remarkably stable cluster consisting of 60 carbon atoms") (1985) and the arc welding approach was a few year later. The paper "Solid C60: a new form of carbon" (1990) paper describes using benzene to dissolve the soot to extract the C60 (https://heyokatc.com/pdfs/MISC/Solid_C60-_a_new_form_of_carb...).

> I don’t think I’ve ever needed compute-concurrency, not in Python anyway.

I have. Some very inexperienced “senior engineers” at my last gig thought it would be fine to build an analytics platform in Python because “Pandas will make it fast”. Unfortunately even modest datasets would cause timeouts and even seize the event loop, while a naive Go prototype would finish in a few hundred milliseconds.

Sam Gross works for Meta, and to my knowledge, this is his #1 project. So in effect, one of the largest companies depending on Python is funding this work.

I don't know if this is still true, but a few years ago there was only a single Python core developer that worked on it full time (Victor Stinner from Red Hat). The rest were only able to devote somewhere between few hours to one day a week.

https://discuss.python.org/t/official-list-of-core-developer...

Łukasz Langa now works full time on CPython via the PSF's Developer in Residence program.

https://pyfound.blogspot.com/2021/07/ukasz-langa-is-inaugura...

Good to hear!

Microsoft has also been funding a team to work full-time on making Python faster: https://developers.slashdot.org/story/21/05/17/0225252/micro...

> If it's such a huge game changer why don't some of the large enterprises which rely on Python fund this work?

Because lots of code in python relies on the GIL to act as a synchronization primitive for threaded code (either explicitly or implicitly) and removing the GIL will break that code in subtle ways and there’s no appetite in those companies to fix that.

It doesn't sound like the reservations of the people in charge of Python are about funding; I don't think it's as simple as "pay them $1m to merge the PR and then pay them salaries as they maintain it". Unless the assumption is that the people in charge of Python would take a bribe, I don't see how large companies could somehow magically make this happen with money short of just forking Python and trying to maintain it themselves, which would burn a ton of goodwill and likely not even win over the community.

Because it's not a huge game changer. What would you do differently if the GIL was gone? when people need speed in Python they write C/C++ extensions or use multiple processes/computers

>Because it's not a huge game changer.

That is just not true.

1 - This helps parallelize regular python code too, like the kind that goes into writing web services.

2 - While you'd still write native extensions to get optimum performance for single threaded code, having the thread dispatch layer in python makes parallelizing execution convenient and robust. For example, see the comment from people who maintain scikit-learn below. I'd love to see python get composable task parallelism like Julia where you can freely spawn threads within threads without worrying about their lifetimes.

link: https://github.com/colesbury/nogil/issues/36#issuecomment-10...

That does not sound all that enthusiastic for a "game changer":

> helps parallelize

> convenient and robust

So nice but not too noticeable?

Well context helps determine impact.

What percentage of compute time is python?

What percent of Py compute time would be cut?

Who's using python?(banks, stem researchers, everyone else)

That has nothing to do with what I wrote and does not address the question?

> ...bunch of questions...

Yeah, if you claim that something is a "game changer" you should provide some arguments, not questions/"help determine".

It might very well be a game changer but thud far you have only suggested there might be an argument for that, if ...

Well for web dev it would be simpler because you can get rid of workers which in turn reduces the overall memory footprint of applications since the code is shared, the local caches are shared and the connections are shared.

Edit: For backend services it would probably put Python around one order of magnitude away from Go in terms of memory usage to serve the same load, enough for teams not to consider switching.

Here's an example: embedding Python in other applications. Out of the box it's impossible to just start running scripts at will from multiple threads. Which happens to be what our application does, because as you say we want some speed/concurrency so have a backend running multiple threads C#/C++. But on top of that some things are customised in Python, and now we use IronPython which has no GIL so that all just works. Is this a huge game changer? As a whole, no, but for us: yes it would be awesome if we could just use Python.Net (which is just a layer over CPython) out of the box without having to deal with it's GIL.

Writing C/C++ extensions is super hard, and not something > 90% of the Python users is willing to pick up. I would love for Python to support a Parallel.ForEach statement as is supported in C#, or for Pandas to support parallel operations.

What if, when people in python need speed, they have the option to just replace a for-loop with threapool.map?

Currently, that doesn't do much. Trying to do this with a processPool either works, or becomes a horrible exercise in fighting with pickle or whatever other serializer you pick.

Run an ordinary database connection pool in shared memory mode instead of offloading it to a separate process via PGBouncer. Do that with all of the other resource pools as well. Heck, for one off webservers with low load you can do in memory session handling without needing to pull in memcache or redis until you truly need multiple processes or the sessions to survive a restart.

What would I do differently? Actually make engineering choices based on the current project status and priorities without having those choices made for me.

They've tried several times, see Unladen Swallow, but usually the projects are way more ambitious and also trying to introduce JIT.

Well, I might prefer a gofundme for some devs to do it. That way us average Joe’s can pitch into the support.

Otherwise, there’s making a fork and attempting periodic updates from python. That’d be a huge undertaking though.

FTA: “”” A lot of the value of Python is the ecosystem, not just the language… CPython really leads the way in terms of the community moving as a block.

"Removing the GIL is a really transformative step. Most Python programs just don’t use threads at the moment if they want to run on multiple cores. If nogil is to be a success, the community as a whole has to buy into it."

– Sam Gross”””

that's exactly what has happened.

edit: not sure why I got flagged, HN. Software engineer hours == funding.

My thoughts exactly. Google has already done quite a lot of work on LLVM, as an example. Python is among their most used programming languages, this something they could totally assemble engineers to do.

Because Java,C#,Golang,Javascript exist.

Wait, does Javascript have good multi-threading support? I dont think it does.

Worker threads[0]. If you don't follow Javascript it's not surprising you hadn't heard about it, it's pretty new. Node also, thanks to v8, pretty much outperforms Python.

[0]https://nodejs.org/api/worker_threads.html

worker threads don't share the parent's heap though, right? They can only share state through a binary channel. It's something, but pretty different from traditional pthreads.

They can use SharedArrayBuffers[0] which wrap shared memory or they can pass ArrayBuffers. Node may not have the shared arrays yet, but the browsers do.

[0]https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

Python has multiprocessing.shared_memory[1] since 3.8 to share arrays between processes, which accomplishes the same thing and circumvents the GIL issue.

[1] https://docs.python.org/3/library/multiprocessing.shared_mem...

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