How to run multiple functions in threads via Curl, keeping them (functions) in the session?

Question

PHP

Task: run several functions in threads via Curl, storing them (functions) in the session.
I ran into a problem:
After writing functions to the session, when trying to start the execution, curl_multi_exec flatly refuses to work.
There are no errors, the request is simply not made.
Is there any analogue of sessions in php that can be worked with in streams? It is desirable that it works on any hosting (without additional modules).

Answer 1

Why store functions, store data.
serialize