Question about callbacks called from "SCTP iterator" thread

[nazar-pc]

I'm not familiar with the library, but while hacking on mediasoup the question arose in versatica/mediasoup#523 as to whether "SCTP iterator" calls any of the callbacks from following functions?:

• usrsctp_init_nothreads
• usrsctp_socket

If the answer is "yes", then my hacking would be blocked by #472.

The use case is that it would be trivial to get mediasoup's worker, that uses usrsctp, to run in a thread if it could use thread-local storage instead of resorting to something more invasive (it currently uses global state for some of its internals). But if callbacks to mentioned functions can be called from other thread then that clearly wouldn't work.

UPD: After further research seems to be a subset of #439