SLEEP(3) Library Functions Manual SLEEP(3)
sleep - suspend execution for interval
The current process is suspended from execution for the number of sec-
onds specified by the argument. The actual suspension time may be up
to 1 second less than that requested, because scheduled wakeups occur
at fixed 1-second intervals, and an arbitrary amount longer because of
other activity in the system.
The routine is implemented by setting an interval timer and pausing
until it occurs. The previous state of this timer is saved and
restored. If the sleep time exceeds the time to the expiration of the
previous timer, the process sleeps only until the signal would have
occurred, and the signal is sent 1 second later.
An interface with finer resolution is needed.
4th Berkeley Distribution 19 January 1983 SLEEP(3)