What is a practical use for PHP's sleep()?

Question

I just had a look at the docs on sleep().

Where would you use this function?

Is it there to give the CPU a break in an expensive function?

Any common

Answer 1

A quick pseudo code example of where you may not want to get millions of alert emails for a single event but you want your script to keep running.

  if CheckSystemCPU() > 95  
        SendMeAnEmail()
        sleep(1800)
  fi