All the functions you use are in std/posix so you can implement it in pure Nim.
You could also use `createThread` as a starting point which already has a pthread_attr struct in usage : <https://github.com/nim-lang/Nim/blob/ae4b47c5bd48d244ee1f93ec6ba5f6bcf55eb973/lib/std/typedthreads.nim#L259> I think if you combine those you can create a more "idiomatic" `createRealTimeThread` in native Nim :)
