gavid

gavid

I have a system that has thousands of run-time generated modules, some of which I want to cache for future reloading.

Ordinarily, the BEAM bytecode for a runtime generated module can be captured like so (How to read the BEAM bytecode compiled into memory and that is not on the disk?):

{:module, ^module_name, binary_contents, _} =
                    module_definition =
                    defmodule module_name do
                      unquote(contents)
                    end

And then saving bytecode to disk. The module can then later be loaded into memory with :code.load_binary or similar (code — OTP 29.0.2 (kernel 11.0.2))

However, the issue with using defmodule and then capturing the output is that because of Erlang’s hot reloading rules, loading versions of a module can cause processes to be killed. (code — OTP 29.0.2 (kernel 11.0.2))

So what I want to be able to do is create a BEAM file for a module without loading into memory.

I see the beginnings of an answer here: Getting each stage of Elixir's compilation all the way to the BEAM bytecode but I’m not sure how to implement what I need using this information.

I am not sure how to create an arbitrary function that will allow me to compile Elixir source code (as string or AST) directly into BEAM without affecting running processes at all.

Does anyone know how to do this? I have been scouring the elixir source code (elixir/lib/elixir/src/elixir_module.erl at 11a493ec4a07479a74e605b409dd16e23bb5cafe · elixir-lang/elixir · GitHub) to try understand how this may be done but I am struggling to get the answer I need.

P.S. Yes I know that when the BEAM file is loaded manually, it will still potentially cause processes to die, but I don’t think that this is avoidable.

Showing Posts 1 to 3

josevalim

josevalim

Creator of Elixir

You can pass @compile {:autoload, false} in the module body.

gavid

gavid OP

@josevalim
Doesn’t that merely delay the issue? Per the docs:

  • @compile {:autoload, false} - disables automatic loading of modules after compilation. Instead, the module will be loaded after it is dispatched to

So that will cause processes to be potentially be killed when the module is dispatched to? I assume “dispatched to” means that functions from it are called?

josevalim

josevalim

Creator of Elixir

If there is a module already loaded, it won’t load the one that was just compiled. Plus, if the bytecode of the module just compiled was not written anywhere in a codepath in disk, then it can’t be found and it won’t be loaded either.

— All posts loaded —

Where Next? Top

Trending in Questions Top

water
I’m aware of 2 such projects, are there others? git: GitHub - team-alembic/realworld: A fullstack Phoenix LiveView application with back...
New
katta
I having some trouble figuring out if I have set myself too strict of standards for my production server. Currently I can handle 75% of r...
New
peck
Hi everyone. My team and I have been working on a fairly modest app based around video streaming and chat, but we’ve landed a customer t...
New
bradley
I really like the adapter patterns that ecto, nebulex, waffle, etc. use and would love find something similar for a key management servic...
New
unaware8150
Hello folks! So at work, we are seeing some situations where we have to define some “fixed” strings that are used across the codebase in...
New
Alvinkariuki
How Can I Optimise Compile Time Dependencies I have been building an elixir application for about 2 years now. Many modules and files ha...
New
leoschweizer
Hi, we run different LLM models across a cluster, with each node loading a configurable subset. Model-specific queues let nodes consume ...
New

Other Trending Topics Top

budgie
A little off-topic, but I feel like people here have a good head on their shoulders. I used to be quite good at making software. Was luc...
New
KristerV
Hey. Is there anyone here who creates agents in their apps? Not talking about using agents, but creating them. I’m finding it pretty diff...
New
mudasobwa
I fully migrated to my own harness from Anthropic/Gemini and I think it’s time to share it. Welcome DSH, the DeepSeek Harness, fully writ...
New
jimsynz
Beam Bots (or just BB for short) is a framework for building fault-tolerant robotics applications in Elixir using familiar OTP patterns. ...
New
juhalehtonen
There has been a thread to discuss the Stack Overflow Developer Survey on this forum every year since 2018, so here’s yet another one for...
New
budgie
I love Elixir. It’s one of 2 programming languages I’ve ever fallen in love with. But I don’t use it anymore. Serverless was the promis...
New

We're in Beta

About us Mission Statement

Options

Thread Display Mode




Thread Preview

Skip Thread Previews