arrayBuffer->Detach() in C++ has more overhead than it was expected to.

[Guthib-of-Dan]

I have recently finished creating 2 TC39 proposals on the way we handle network data in JavaScript - "JSON.parseBinary" and "ArrayBuffer.prototype.detach" (the one I am going to talk about now).

Let me promote these. I want github stars: https://github.com/Guthib-of-Dan/proposal-arraybuffer-detach; https://github.com/Guthib-of-Dan/proposal-json-parse-binary/

Both proposals contain benchmarks to make a solid background for the idea and "proposal-arraybuffer-detach" has an example with C++ V8 API and NAPI, where I call some js callback in a loop from C++, give it an ArrayBuffer over existing memory and detach that memory after the callback (or IN the callback). Just like uWebSockets.js does.
The nuance is that results do have a difference, which is unnoticeable at first.

V8 API
──────────────────────────────────────────────────────────────────
  warmup                      ██████████░░░░░░░░░░░░░░░░░░    9.297 s
  C++ detach via JS call      █████████░░░░░░░░░░░░░░░░░░░    8.067 s  8.0% faster than C++ auto-detach  ⚑
  C++ detach after callback   █████████░░░░░░░░░░░░░░░░░░░    8.766 s  C++ post-callback detach
  internalDetach()            ████████░░░░░░░░░░░░░░░░░░░░    7.945 s
  C++ detach after cb (2nd)   █████████░░░░░░░░░░░░░░░░░░░    8.935 s  C++ post-callback detach
  internalDetach() (2nd)      ████████░░░░░░░░░░░░░░░░░░░░    8.023 s
  no detach                   ████████████████████████████   26.546 s  3.2× slower than avg detach

What an AI suggest is that inside the callback "ArrayBuffer" as a param is kept hot in memory, but after callback - not. Also this is not just about speed, this is about immediately handling the memory you know you needn't after some parsing (gc-pressure test in that repo suggest that leaving GC handle all that memory comes at a huge cost).

What should you do with this?

So we can create new handlers or extend existing functionality to support manual memory management. Everything, obviously, has a sense of integrating only if at least "proposal-arraybuffer-detach" gets its deserved appraisal.

Btw, don't you mind me mentioning uWebSockets.js in my proposal?

It is already there in README, but this discussion is the first place where it goes to. Do you have any objections?

[uNetworkingAB]

this is about immediately handling the memory you know you needn't after some parsing (gc-pressure test in that repo suggest that leaving GC handle all that memory comes at a huge cost).

Lol. Well, yes.

Rust, C, C++ are fast because they inherently do not have a GC. Go, Java, JavaScript, Haskell are slow because they are inherently designed around a GC.

Proposing manual memory management for JavaScript is like proposing Atheism to be more like Islam. It's the wrong venue.

[uNetworkingAB]

I mean it speeds things up, doesn’t it? At least in the benchmark.

It's like saying Ice cream tastes too much like ice cream I want it to taste like Broccoli because Broccoli is better, in a convention about Ice cream instead of just buying a ticket to the broccoli convention.

[Guthib-of-Dan]

Alright. So the last question

should I remove mentioning uWS.js from the proposal?

[uNetworkingAB]

So that’s a “no” for extending existing functionality.

I never said that, and I have zero authority over what you want to propose. Propose whatever you want. I'm just saying, generally speaking, that most people are retarded and won't agree with your opinion.

My opinion is that JS should a) remove the GC entirely b) remove dynamic typing and have only static types and c) be replaced in its entirety with something entirely different. But 99% of programmers disagree because of before mentioned retardation.

[Guthib-of-Dan]

And still, I don’t try to bring something groundbreaking to js. I just want one function that does a little less work than its equivalent .transfer(0). No one forbids using it now.

[Guthib-of-Dan]

And yes, I share your thoughts considering someone’s high-level knowledge and “React-only” experience. But not trying is worse than trying and getting a rejection, isn’t it?