c/program/at quick exit

Registers the function pointed to by to be called on quick program termination (via quick_exit).

Calling the function from several threads does not induce a data race. The implementation is guaranteed to support the registration of at least 32 functions. The exact limit is implementation-defined.

The registered functions will not be called on. If a function need to be called in that case, atexit must be used.

Return value
if the registration succeeds, nonzero value otherwise.