lib/libkse/thread/thr_nanosleep.c

   1 /*
   2  * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by John Birrell.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  */
  33 #include <stdio.h>
  34 #include <errno.h>
  35 #ifdef _THREAD_SAFE
  36 #include <pthread.h>
  37 #include "pthread_private.h"
  38
  39 int
  40 nanosleep(const struct timespec * time_to_sleep,
  41                   struct timespec * time_remaining)
  42 {
  43         int             ret = 0;
  44         struct timespec current_time;
  45         struct timespec current_time1;
  46         struct timespec remaining_time;
  47         struct timeval  tv;
  48
  49         /* Check if the time to sleep is legal: */
  50         if (time_to_sleep == NULL || time_to_sleep->tv_nsec < 0 || time_to_sleep->tv_nsec > 1000000000) {
  51                 /* Return an EINVAL error : */
  52                 errno = EINVAL;
  53                 ret = -1;
  54         } else {
  55                 /* Get the current time: */
  56                 gettimeofday(&tv, NULL);
  57                 TIMEVAL_TO_TIMESPEC(&tv, &current_time);
  58
  59                 /* Calculate the time for the current thread to wake up: */
  60                 _thread_run->wakeup_time.tv_sec = current_time.tv_sec + time_to_sleep->tv_sec;
  61                 _thread_run->wakeup_time.tv_nsec = current_time.tv_nsec + time_to_sleep->tv_nsec;
  62
  63                 /* Check if the nanosecond field has overflowed: */
  64                 if (_thread_run->wakeup_time.tv_nsec >= 1000000000) {
  65                         /* Wrap the nanosecond field: */
  66                         _thread_run->wakeup_time.tv_sec += 1;
  67                         _thread_run->wakeup_time.tv_nsec -= 1000000000;
  68                 }
  69                 _thread_run->interrupted = 0;
  70
  71                 /* Reschedule the current thread to sleep: */
  72                 _thread_kern_sched_state(PS_SLEEP_WAIT, __FILE__, __LINE__);
  73
  74                 /* Get the current time: */
  75                 gettimeofday(&tv, NULL);
  76                 TIMEVAL_TO_TIMESPEC(&tv, &current_time1);
  77
  78                 /* Calculate the remaining time to sleep: */
  79                 remaining_time.tv_sec = time_to_sleep->tv_sec + current_time.tv_sec - current_time1.tv_sec;
  80                 remaining_time.tv_nsec = time_to_sleep->tv_nsec + current_time.tv_nsec - current_time1.tv_nsec;
  81
  82                 /* Check if the nanosecond field has underflowed: */
  83                 if (remaining_time.tv_nsec < 0) {
  84                         /* Handle the underflow: */
  85                         remaining_time.tv_sec -= 1;
  86                         remaining_time.tv_nsec += 1000000000;
  87                 }
  88
  89                 /* Check if the nanosecond field has overflowed: */
  90                 if (remaining_time.tv_nsec >= 1000000000) {
  91                         /* Handle the overflow: */
  92                         remaining_time.tv_sec += 1;
  93                         remaining_time.tv_nsec -= 1000000000;
  94                 }
  95
  96                 /* Check if the sleep was longer than the required time: */
  97                 if (remaining_time.tv_sec < 0) {
  98                         /* Reset the time left: */
  99                         remaining_time.tv_sec = 0;
 100                         remaining_time.tv_nsec = 0;
 101                 }
 102
 103                 /* Check if the time remaining is to be returned: */
 104                 if (time_remaining != NULL) {
 105                         /* Return the actual time slept: */
 106                         time_remaining->tv_sec = remaining_time.tv_sec;
 107                         time_remaining->tv_nsec = remaining_time.tv_nsec;
 108                 }
 109
 110                 /* Check if the sleep was interrupted: */
 111                 if (_thread_run->interrupted) {
 112                         /* Return an EINTR error : */
 113                         errno = EINTR;
 114                         ret = -1;
 115                 }
 116         }
 117         return (ret);
 118 }
 119 #endif