privalloc, privfree – per–process private storage management|
void privfree(void **p)
Privalloc returns a pointer to a per–process private storage location.
The location is not shared among processes, even if they share
the same data segments. It returns nil if there are no free slots
Privfree releases a location allocated with privalloc. It is legal
to call privfree with p set to nil.