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. 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
  32 #include "namespace.h"
  33 #include <stdio.h>
  34 #include <errno.h>
  35 #include <pthread.h>
  36 #include "un-namespace.h"
  37 #include "thr_private.h"
  38
  39 int     __nanosleep(const struct timespec *time_to_sleep,
  40             struct timespec *time_remaining);
  41
  42 __weak_reference(__nanosleep, nanosleep);
  43
  44 int
  45 _nanosleep(const struct timespec *time_to_sleep,
  46     struct timespec *time_remaining)
  47 {
  48         struct pthread  *curthread = _get_curthread();
  49         int             ret = 0;
  50         struct timespec ts, ts1;
  51         struct timespec remaining_time;
  52         struct timespec wakeup_time;
  53
  54         /* Check if the time to sleep is legal: */
  55         if ((time_to_sleep == NULL) || (time_to_sleep->tv_sec < 0) ||
  56             (time_to_sleep->tv_nsec < 0) ||
  57             (time_to_sleep->tv_nsec >= 1000000000)) {
  58                 /* Return an EINVAL error : */
  59                 errno = EINVAL;
  60                 ret = -1;
  61         } else {
  62                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  63                         return (__sys_nanosleep(time_to_sleep, time_remaining));
  64
  65                 KSE_GET_TOD(curthread->kse, &ts);
  66
  67                 /* Calculate the time for the current thread to wake up: */
  68                 TIMESPEC_ADD(&wakeup_time, &ts, time_to_sleep);
  69
  70                 THR_LOCK_SWITCH(curthread);
  71                 curthread->interrupted = 0;
  72                 curthread->wakeup_time = wakeup_time;
  73                 THR_SET_STATE(curthread, PS_SLEEP_WAIT);
  74
  75                 /* Reschedule the current thread to sleep: */
  76                 _thr_sched_switch_unlocked(curthread);
  77
  78                 /* Calculate the remaining time to sleep: */
  79                 KSE_GET_TOD(curthread->kse, &ts1);
  80                 remaining_time.tv_sec = time_to_sleep->tv_sec
  81                     + ts.tv_sec - ts1.tv_sec;
  82                 remaining_time.tv_nsec = time_to_sleep->tv_nsec
  83                     + ts.tv_nsec - ts1.tv_nsec;
  84
  85                 /* Check if the nanosecond field has underflowed: */
  86                 if (remaining_time.tv_nsec < 0) {
  87                         /* Handle the underflow: */
  88                         remaining_time.tv_sec -= 1;
  89                         remaining_time.tv_nsec += 1000000000;
  90                 }
  91                 /* Check if the nanosecond field has overflowed: */
  92                 else if (remaining_time.tv_nsec >= 1000000000) {
  93                         /* Handle the overflow: */
  94                         remaining_time.tv_sec += 1;
  95                         remaining_time.tv_nsec -= 1000000000;
  96                 }
  97
  98                 /* Check if the sleep was longer than the required time: */
  99                 if (remaining_time.tv_sec < 0) {
 100                         /* Reset the time left: */
 101                         remaining_time.tv_sec = 0;
 102                         remaining_time.tv_nsec = 0;
 103                 }
 104
 105                 /* Check if the time remaining is to be returned: */
 106                 if (time_remaining != NULL) {
 107                         /* Return the actual time slept: */
 108                         time_remaining->tv_sec = remaining_time.tv_sec;
 109                         time_remaining->tv_nsec = remaining_time.tv_nsec;
 110                 }
 111
 112                 /* Check if the sleep was interrupted: */
 113                 if (curthread->interrupted) {
 114                         /* Return an EINTR error : */
 115                         errno = EINTR;
 116                         ret = -1;
 117                 }
 118         }
 119         return (ret);
 120 }
 121
 122 int
 123 __nanosleep(const struct timespec *time_to_sleep,
 124     struct timespec *time_remaining)
 125 {
 126         struct pthread *curthread = _get_curthread();
 127         int             ret;
 128
 129         _thr_cancel_enter(curthread);
 130         ret = _nanosleep(time_to_sleep, time_remaining);
 131         _thr_cancel_leave(curthread, 1);
 132
 133         return (ret);
 134 }