25.2.4 sleep [Function]

sleep seconds ⇒ nil

Arguments and Values::

seconds—a non-negative real.

Description::

Causes execution to cease and become dormant for approximately the seconds of real time indicated by seconds, whereupon execution is resumed.

Examples::

 (sleep 1) ⇒  NIL 

;; Actually, since SLEEP is permitted to use approximate timing, 
;; this might not always yield true, but it will often enough that
;; we felt it to be a productive example of the intent.
 (let ((then (get-universal-time))
       (now  (progn (sleep 10) (get-universal-time))))
   (>= (- now then) 10))
⇒  true

Side Effects::

Causes processing to pause.

Affected By::

The granularity of the scheduler.

Exceptional Situations::

Should signal an error of type type-error if seconds is not a non-negative real.