OBSOLETE. The CRT exports these internal functions only to preserve binary compatibility.
Although the internal CRT functions ___setlc_active_func and ___unguarded_readlc_active_add_func are obsolete and no longer used, they are exported by the CRT library to preserve binary compatibility. The original purpose of ___setlc_active_func was to return the number of currently active calls to the setlocale function. The original purpose of ___unguarded_readlc_active_add_func was to return the number of functions that referenced the locale without locking it.