gen/nanosleep.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <errno.h>
  25 #include <sys/time.h>
  26 #include <mach/message.h>
  27 #include <mach/mach_error.h>
  28 #include <mach/mach_syscalls.h>
  29 #include <mach/clock.h>
  30 #include <mach/clock_types.h>
  31 #include <stdio.h>
  32
  33 extern mach_port_t clock_port;
  34
  35 int
  36 nanosleep(const struct timespec *requested_time, struct timespec *remaining_time) {
  37     kern_return_t ret;
  38     mach_timespec_t remain;
  39     mach_timespec_t current;
  40
  41     if ((requested_time == NULL) || (requested_time->tv_sec < 0) || (requested_time->tv_nsec > NSEC_PER_SEC)) {
  42         errno = EINVAL;
  43         return -1;
  44     }
  45
  46     ret = clock_get_time(clock_port, &current);
  47     if (ret != KERN_SUCCESS) {
  48         fprintf(stderr, "clock_get_time() failed: %s\n", mach_error_string(ret));
  49         return -1;
  50     }
  51     /* This depends on the layout of a mach_timespec_t and timespec_t being equivalent */
  52     ret = clock_sleep_trap(clock_port, TIME_RELATIVE, requested_time->tv_sec, requested_time->tv_nsec, &remain);
  53     if (ret != KERN_SUCCESS) {
  54         if (ret == KERN_ABORTED) {
  55             errno = EINTR;
  56             if (remaining_time != NULL) {
  57                 ret = clock_get_time(clock_port, &remain);
  58                 if (ret != KERN_SUCCESS) {
  59                     fprintf(stderr, "clock_get_time() failed: %s\n", mach_error_string(ret));
  60                     return -1;
  61                 }
  62                 ADD_MACH_TIMESPEC(&current, requested_time);
  63                 SUB_MACH_TIMESPEC(&current, &remain);
  64                 remaining_time->tv_sec = current.tv_sec;
  65                 remaining_time->tv_nsec = current.tv_nsec;
  66             }
  67         } else {
  68             errno = EINVAL;
  69         }
  70         return -1;
  71     }
  72     return 0;
  73 }