Neither poll nor select are deprecated. They're just not good fits for particular use patterns. But even select() is fine if you just need to watch 2 FDs in a CLI tool.
In fact, due to its footguns, I'd highly advise against epoll (particularly edge triggering) unless you really need it.
Only if those fds are below ~1024 or whatever. (If you're going to use one of the legacy interfaces, at least poll() doesn't have arbitrary limits on the numeric value of the fd.)
Right now I am working on JavaScript bindings for a project and doing it the node.js way (or Deno) is definitely a no-no. That would be one more layer in the architecture, if not two. Once you have more layers, you also have more layer interactions and that never stops.
I mean, complexity begets complexity
https://github.com/gritzko/librdx/blob/master/js/README.md
Having more than 1000 conns per a thread is a very specific usecase.
Imagine what sort of traffic you need to saturate 1000 conns with HTTP. Can your single thread app handle it? If you are not using nginx, that must be something less trivial than a reverse proxy. Nginx can do lots of things, by the way.
https://man.freebsd.org/cgi/man.cgi?select
The man page also suggests how you might increase the FD limit if needed. I still use select for a small number of FDs where overhead isn't a real concern, and select is a good fit.
They're basically identical apis but poll doesn't have a hard limit and works with high number fds.
So the obvious loop using level triggering switched to edge will eventually lock up.
You'll read 4092bbytesbwhen there is 4093 bytes leaving 1 behind and then never get a signal again.
Just don't try to solve the 10,000x problem with it, by putting it on the Internet.
Or, if you do, build it out properly.
Or use epoll or kqueue.