(PECL eio >= 0.0.1dev)
eio_busy — Artificially increase load. Could be useful in tests, benchmarking.
$delay
   [, int $pri = EIO_PRI_DEFAULT
   [, callable $callback = NULL
   [, mixed $data = NULL
  ]]] )
  eio_busy() artificially increases load taking
  delay seconds to execute. May be used for debugging,
  or benchmarking.
  
delayDelay in seconds
priThe request priority: EIO_PRI_DEFAULT, EIO_PRI_MIN, EIO_PRI_MAX, or NULL.
If NULL passed, pri internally is set to
EIO_PRI_DEFAULT.
callbackThis callback is called when all the group requests are done.
data
     Arbitrary variable passed to callback.
     
   eio_busy() returns request resource on success or FALSE on error.