[tightbookkeeper]

The cost to write and debug multithreaded code is high and not limited to the area you use it. And for all that you get a 2-8x speed up.

So if you care about performance why are you writing that part in python?

> multi-core CPUs we're commonly running it on today.

If you spawn processes to do work you get multi core for free. Think of the whole system, not just your program.

[kstrauser]

Pretend for a second that I'm in a setting where:

1. The whole system is dedicated to running my one program, 2. I want to use multi threading to share large amounts of state between workers because that's appropriate to my specific use case, and 3. A 2-8x speedup without having to re-write parts of the code in another language would be fan-freaking-tastic.

In other worse, I know what I'm doing, I've been doing this since the 90s, and I can imagine this improvement unlocking a whole lot of use cases that've been previously unviable.

[tightbookkeeper]

You can imagine that situation. But all python code is now impacted to support that case.

Having a “python only” ecosystem makes about as much sense as a “bash only” ecosystem. Your tech stack includes much more.

> In other worse, I know what I'm doing, I've been doing this since the 90s

ditto. So that’s not relevant.

[kstrauser]

Sounds like a lot of speculation on your end because we don't have lots of evidence about how much this will affect anything, because until just now it's not been possible to get that information.

> ditto. So that’s not relevant.

Then I'm genuinely surprised you've never once stumbled across one of the many, many use cases where multithreaded CPU-intensive code would be a nice, obvious solution to a problem. You seem to think these are hypothetical and my experience has been that these are very real.

[tightbookkeeper]

> Sounds like a lot of speculation on your end

This issue is discussed extensively in “the art of Unix programming” if we want to play the authority and experience game.

> multithreaded CPU-intensive code would be a nice, obvious solution to a problem

Processes are well supported in python. But if you’re maxing your CPU core with the right algorithm then python was probably the wrong tool.

> my experience has been that these are very real.

When you’re used to working one way it may seem impossible to frame the problem differently. Just to remind you this is a NEW feature in python. JavaScript, perl, and bash, also do not support multi threading for similar reasons.

One school of design says if you can think of a use case, add that feature. Another tries to maintain invariants of a system.