gen/sleep.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25
  26 #include <sys/time.h>
  27
  28 extern int nanosleep(const struct timespec *, struct timespec *);
  29
  30 /* We use nanosleep and let it set errno, and compute the residual for us. */
  31 unsigned int
  32 sleep(unsigned int seconds)
  33 {
  34     struct timespec req, rem;
  35
  36     if (seconds == 0) {
  37         return 0;
  38     }
  39     req.tv_sec = seconds;
  40     req.tv_nsec = 0;
  41
  42     /* It's not clear from the spec whether the remainder will be 0
  43     ** if we weren't interrupted
  44     */
  45     if (nanosleep(&req, &rem) == -1) {
  46         return (unsigned int)rem.tv_sec;
  47     }
  48     return 0;
  49 }