How to define thread-local local static variables?

Question

How to define local static variables (that keeps its value between function calls) that are not shared among different threads?

I am looking for an answer both in C

Answer 1

The current C standard has no model for threads or alike, so you can't get an answer, there.

The utility foreseen by POSIX for that is pthread_[gs]etspecific.

The next version of the C standard adds threads and has a concept of thread local storage.