'lock' mentioned in perlfunc, references self in threads implementsion, but no reference

the perl function 'lock()' is documented in perlfunc, and says it will place an advisory
lock on "THING".  the manpage says it will always be defined when one uses threads.

<Cool sounds like what I want...>
man 3pm threads ->
	no mention of lock() or how to test it.

Is an oversight, or should a user be looking elsewhere?

• 'lock' mentioned in perlfunc, references self in threads implementsion, but no reference by Linda W
• Re: 'lock' mentioned in perlfunc, references self in threadsimplementsion, but no reference by Chas. Owens