nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_timedwait.c

   1 /* sem_timedwait -- wait on a semaphore.  SPARC version.
   2    Copyright (C) 2003, 2006, 2007 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <sysdep.h>
  23 #include <lowlevellock.h>
  24 #include <internaltypes.h>
  25 #include <semaphore.h>
  26
  27 #include <pthreadP.h>
  28 #include <shlib-compat.h>
  29
  30
  31 extern void __sem_wait_cleanup (void *arg) attribute_hidden;
  32
  33
  34 int
  35 sem_timedwait (sem_t *sem, const struct timespec *abstime)
  36 {
  37   struct sparc_new_sem *isem = (struct sparc_new_sem *) sem;
  38   int err;
  39   int val;
  40
  41   if (__atomic_is_v9)
  42     val = atomic_decrement_if_positive (&isem->value);
  43   else
  44     {
  45       __sparc32_atomic_do_lock24 (&isem->lock);
  46       val = isem->value;
  47       if (val > 0)
  48         isem->value = val - 1;
  49       __sparc32_atomic_do_unlock24 (&isem->lock);
  50     }
  51
  52   if (val > 0)
  53     return 0;
  54
  55   if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
  56     {
  57       __set_errno (EINVAL);
  58       return -1;
  59     }
  60
  61   if (__atomic_is_v9)
  62     atomic_increment (&isem->nwaiters);
  63   else
  64     {
  65       __sparc32_atomic_do_lock24 (&isem->lock);
  66       isem->nwaiters++;
  67       __sparc32_atomic_do_unlock24 (&isem->lock);
  68     }
  69
  70   pthread_cleanup_push (__sem_wait_cleanup, isem);
  71
  72   while (1)
  73     {
  74       struct timeval tv;
  75       struct timespec rt;
  76       int sec, nsec;
  77
  78       /* Get the current time.  */
  79       __gettimeofday (&tv, NULL);
  80
  81       /* Compute relative timeout.  */
  82       sec = abstime->tv_sec - tv.tv_sec;
  83       nsec = abstime->tv_nsec - tv.tv_usec * 1000;
  84       if (nsec < 0)
  85         {
  86           nsec += 1000000000;
  87           --sec;
  88         }
  89
  90       /* Already timed out?  */
  91       err = -ETIMEDOUT;
  92       if (sec < 0)
  93         {
  94           __set_errno (ETIMEDOUT);
  95           err = -1;
  96           break;
  97         }
  98
  99       /* Do wait.  */
 100       rt.tv_sec = sec;
 101       rt.tv_nsec = nsec;
 102
 103       /* Enable asynchronous cancellation.  Required by the standard.  */
 104       int oldtype = __pthread_enable_asynccancel ();
 105
 106       err = lll_futex_timed_wait (&isem->value, 0, &rt,
 107                                   isem->private ^ FUTEX_PRIVATE_FLAG);
 108
 109       /* Disable asynchronous cancellation.  */
 110       __pthread_disable_asynccancel (oldtype);
 111
 112       if (err != 0 && err != -EWOULDBLOCK)
 113         {
 114           __set_errno (-err);
 115           err = -1;
 116           break;
 117         }
 118
 119       if (__atomic_is_v9)
 120         val = atomic_decrement_if_positive (&isem->value);
 121       else
 122         {
 123           __sparc32_atomic_do_lock24 (&isem->lock);
 124           val = isem->value;
 125           if (val > 0)
 126             isem->value = val - 1;
 127           __sparc32_atomic_do_unlock24 (&isem->lock);
 128         }
 129
 130       if (val > 0)
 131         {
 132           err = 0;
 133           break;
 134         }
 135     }
 136
 137   pthread_cleanup_pop (0);
 138
 139   if (__atomic_is_v9)
 140     atomic_decrement (&isem->nwaiters);
 141   else
 142     {
 143       __sparc32_atomic_do_lock24 (&isem->lock);
 144       isem->nwaiters--;
 145       __sparc32_atomic_do_unlock24 (&isem->lock);
 146     }
 147
 148   return err;
 149 }