I wrote a NIF which have function that can take a long time to run. To prevent the scheduler from being overloaded with long running functions (even if marked at dirty), I made my NIF threaded and it sends message back to erlang using enif_send. I want to make those call synchronous from a “program…

It could work but in my opinion it’s best to use a yielding NIF or spawn an extra process and use local means of communication.

My NIF is blocking and it is hard to make it non blocking, so I wrapped the entire function into a C thread, my NIF now spawn the thread and return immediately, then the thread sends the message. It seems to be a recommenced architecture in the documentation. Threaded NIF - This is accomplished by…

Why wrap it in a task at all? Can you simply have a function that calls the NIF and then does a receive right after? What does this NIF do btw? How long does it run?

The calling process might have other messages in its inbox when I call this function, I didn’t want to mess with that. This nif does some GPU inference, it runs for about 5 seconds. I know it could/should be an external port, but using nif I get all serialize/deserialize for free and it is very pra…

[image] kuon: The calling process might have other messages in its inbox when I call this function, I didn’t want to mess with that. Namespacing and a selective receive would to that.

So I can just do receive do {:my_namespace, …} → <we are done> end and it will not mess with the inbox? I wasn’t sure of that.

I’ll remove the matches message from the inbox – but it’ll leave anything else as is.

Making async code synchronous

Questions & Help Questions

LostKobrakai September 23, 2025, 12:26pm 6

Namespacing and a selective receive would to that.