gen/sleep.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22
  23 #include <sys/time.h>
  24
  25 extern int nanosleep(const struct timespec *, struct timespec *);
  26
  27 /* We use nanosleep and let it set errno, and compute the residual for us. */
  28 unsigned int
  29 sleep(unsigned int seconds)
  30 {
  31     struct timespec req, rem;
  32
  33     if (seconds == 0) {
  34         return 0;
  35     }
  36     req.tv_sec = seconds;
  37     req.tv_nsec = 0;
  38
  39     /* It's not clear from the spec whether the remainder will be 0
  40     ** if we weren't interrupted
  41     */
  42     if (nanosleep(&req, &rem) == -1) {
  43         return (unsigned int)rem.tv_sec;
  44     }
  45     return 0;
  46 }