=item locked
+B<5.005 threads only! The use of the "locked" attribute currently
+only makes sense if you are using the deprecated "Perl 5.005 threads"
+implementation of threads.>
+
Setting this attribute is only meaningful when the subroutine or
method is to be called by multiple threads. When set on a method
subroutine (i.e., one marked with the B<method> attribute below),