lib/libc_r/uthread/uthread_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. Neither the name of the author nor the names of any co-contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD$
  30  */
  31 #include <stdio.h>
  32 #include <errno.h>
  33 #include <pthread.h>
  34 #include "pthread_private.h"
  35
  36 __weak_reference(__nanosleep, nanosleep);
  37
  38 int
  39 _nanosleep(const struct timespec * time_to_sleep,
  40     struct timespec * time_remaining)
  41 {
  42         struct pthread  *curthread = _get_curthread();
  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_sec < 0 ||
  51                 time_to_sleep->tv_nsec < 0 || time_to_sleep->tv_nsec >= 1000000000) {
  52                 /* Return an EINVAL error : */
  53                 errno = EINVAL;
  54                 ret = -1;
  55         } else {
  56                 /*
  57                  * As long as we're going to get the time of day, we
  58                  * might as well store it in the global time of day:
  59                  */
  60                 gettimeofday((struct timeval *) &_sched_tod, NULL);
  61                 GET_CURRENT_TOD(tv);
  62                 TIMEVAL_TO_TIMESPEC(&tv, &current_time);
  63
  64                 /* Calculate the time for the current thread to wake up: */
  65                 curthread->wakeup_time.tv_sec = current_time.tv_sec + time_to_sleep->tv_sec;
  66                 curthread->wakeup_time.tv_nsec = current_time.tv_nsec + time_to_sleep->tv_nsec;
  67
  68                 /* Check if the nanosecond field has overflowed: */
  69                 if (curthread->wakeup_time.tv_nsec >= 1000000000) {
  70                         /* Wrap the nanosecond field: */
  71                         curthread->wakeup_time.tv_sec += 1;
  72                         curthread->wakeup_time.tv_nsec -= 1000000000;
  73                 }
  74                 curthread->interrupted = 0;
  75
  76                 /* Reschedule the current thread to sleep: */
  77                 _thread_kern_sched_state(PS_SLEEP_WAIT, __FILE__, __LINE__);
  78
  79                 /*
  80                  * As long as we're going to get the time of day, we
  81                  * might as well store it in the global time of day:
  82                  */
  83                 gettimeofday((struct timeval *) &_sched_tod, NULL);
  84                 GET_CURRENT_TOD(tv);
  85                 TIMEVAL_TO_TIMESPEC(&tv, &current_time1);
  86
  87                 /* Calculate the remaining time to sleep: */
  88                 remaining_time.tv_sec = time_to_sleep->tv_sec + current_time.tv_sec - current_time1.tv_sec;
  89                 remaining_time.tv_nsec = time_to_sleep->tv_nsec + current_time.tv_nsec - current_time1.tv_nsec;
  90
  91                 /* Check if the nanosecond field has underflowed: */
  92                 if (remaining_time.tv_nsec < 0) {
  93                         /* Handle the underflow: */
  94                         remaining_time.tv_sec -= 1;
  95                         remaining_time.tv_nsec += 1000000000;
  96                 }
  97
  98                 /* Check if the nanosecond field has overflowed: */
  99                 if (remaining_time.tv_nsec >= 1000000000) {
 100                         /* Handle the overflow: */
 101                         remaining_time.tv_sec += 1;
 102                         remaining_time.tv_nsec -= 1000000000;
 103                 }
 104
 105                 /* Check if the sleep was longer than the required time: */
 106                 if (remaining_time.tv_sec < 0) {
 107                         /* Reset the time left: */
 108                         remaining_time.tv_sec = 0;
 109                         remaining_time.tv_nsec = 0;
 110                 }
 111
 112                 /* Check if the time remaining is to be returned: */
 113                 if (time_remaining != NULL) {
 114                         /* Return the actual time slept: */
 115                         time_remaining->tv_sec = remaining_time.tv_sec;
 116                         time_remaining->tv_nsec = remaining_time.tv_nsec;
 117                 }
 118
 119                 /* Check if the sleep was interrupted: */
 120                 if (curthread->interrupted) {
 121                         /* Return an EINTR error : */
 122                         errno = EINTR;
 123                         ret = -1;
 124                 }
 125         }
 126         return (ret);
 127 }
 128
 129 int
 130 __nanosleep(const struct timespec * time_to_sleep, struct timespec *
 131     time_remaining)
 132 {
 133         int     ret;
 134
 135         _thread_enter_cancellation_point();
 136         ret = _nanosleep(time_to_sleep, time_remaining);
 137         _thread_leave_cancellation_point();
 138
 139         return ret;
 140 }