VMS Help POSIX Threads, PTHREAD routines, pthread_attr_destroy, Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    This routine destroys a thread attributes object. Call this
    routine when a thread attributes object will no longer be
    referenced.

    Threads that were created using this thread attributes object are
    not affected by the destruction of the thread attributes object.

    The results of calling this routine are unpredictable if
    the value specified by the attr argument refers to a thread
    attributes object that does not exist.