 absolute
time specified by <I>abs_timeout</I> has already been passed at the
time of the call. 
</P>
<P>The <B>timespec</B> data type is defined in the <I>&lt;time.h&gt;</I>
header. Under no circumstances shall the function fail with a timeout
if the lock can be acquired immediately. The validity of the
<I>abs_timeout</I> parameter need not be checked if the lock can be
immediately acquired. 
</P>
<P>The calling thread may deadlock if at the time the call is made it
holds a write lock on <I>rwlock</I>. The