B>pthread_setspecific</B> changes the value associated with <I>key</I>
in the calling thread, storing the given <I>pointer</I> instead. 
</P>
<P><B>pthread_getspecific</B> returns the value currently associated
with <I>key</I> in the calling thread. 
</P>
<P>The routines <B>pthread_setspecific</B>, <B>pthread_getspecific</B>,
and <B>pthread_key_delete</B> can be called from <I>destr_function</I>
targeting any valid key including the key on which <I>destr_function</I>
is currently operating. If <B>pthread_ge