sysdeps/sparc/sparc32/sem_timedwait.c

   1 /* sem_timedwait -- wait on a semaphore.  SPARC version.
   2    Copyright (C) 2003-2015 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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <sysdep.h>
  22 #include <lowlevellock.h>
  23 #include <internaltypes.h>
  24 #include <semaphore.h>
  25
  26 #include <pthreadP.h>
  27 #include <shlib-compat.h>
  28 #include <sparc-nptl.h>
  29
  30 extern void __sem_wait_cleanup (void *arg) attribute_hidden;
  31
  32 /* This is in a seperate function in order to make sure gcc
  33    puts the call site into an exception region, and thus the
  34    cleanups get properly run.  */
  35 static int
  36 __attribute__ ((noinline))
  37 do_futex_timed_wait (struct sparc_new_sem *isem, struct timespec *rt)
  38 {
  39   int err, oldtype = __pthread_enable_asynccancel ();
  40
  41   err = lll_futex_timed_wait (&isem->value, 0, rt,
  42                               isem->private ^ FUTEX_PRIVATE_FLAG);
  43
  44   __pthread_disable_asynccancel (oldtype);
  45   return err;
  46 }
  47
  48 int
  49 sem_timedwait (sem_t *sem, const struct timespec *abstime)
  50 {
  51   struct sparc_new_sem *isem = (struct sparc_new_sem *) sem;
  52   int err;
  53   int val;
  54
  55   if (__atomic_is_v9)
  56     val = atomic_decrement_if_positive (&isem->value);
  57   else
  58     {
  59       __sparc32_atomic_do_lock24 (&isem->lock);
  60       val = isem->value;
  61       if (val > 0)
  62         isem->value = val - 1;
  63       __sparc32_atomic_do_unlock24 (&isem->lock);
  64     }
  65
  66   if (val > 0)
  67     return 0;
  68
  69   if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
  70     {
  71       __set_errno (EINVAL);
  72       return -1;
  73     }
  74
  75   if (__atomic_is_v9)
  76     atomic_increment (&isem->nwaiters);
  77   else
  78     {
  79       __sparc32_atomic_do_lock24 (&isem->lock);
  80       isem->nwaiters++;
  81       __sparc32_atomic_do_unlock24 (&isem->lock);
  82     }
  83
  84   pthread_cleanup_push (__sem_wait_cleanup, isem);
  85
  86   while (1)
  87     {
  88       struct timeval tv;
  89       struct timespec rt;
  90       int sec, nsec;
  91
  92       /* Get the current time.  */
  93       __gettimeofday (&tv, NULL);
  94
  95       /* Compute relative timeout.  */
  96       sec = abstime->tv_sec - tv.tv_sec;
  97       nsec = abstime->tv_nsec - tv.tv_usec * 1000;
  98       if (nsec < 0)
  99         {
 100           nsec += 1000000000;
 101           --sec;
 102         }
 103
 104       /* Already timed out?  */
 105       if (sec < 0)
 106         {
 107           __set_errno (ETIMEDOUT);
 108           err = -1;
 109           break;
 110         }
 111
 112       /* Do wait.  */
 113       rt.tv_sec = sec;
 114       rt.tv_nsec = nsec;
 115       err = do_futex_timed_wait(isem, &rt);
 116       if (err != 0 && err != -EWOULDBLOCK)
 117         {
 118           __set_errno (-err);
 119           err = -1;
 120           break;
 121         }
 122
 123       if (__atomic_is_v9)
 124         val = atomic_decrement_if_positive (&isem->value);
 125       else
 126         {
 127           __sparc32_atomic_do_lock24 (&isem->lock);
 128           val = isem->value;
 129           if (val > 0)
 130             isem->value = val - 1;
 131           __sparc32_atomic_do_unlock24 (&isem->lock);
 132         }
 133
 134       if (val > 0)
 135         {
 136           err = 0;
 137           break;
 138         }
 139     }
 140
 141   pthread_cleanup_pop (0);
 142
 143   if (__atomic_is_v9)
 144     atomic_decrement (&isem->nwaiters);
 145   else
 146     {
 147       __sparc32_atomic_do_lock24 (&isem->lock);
 148       isem->nwaiters--;
 149       __sparc32_atomic_do_unlock24 (&isem->lock);
 150     }
 151
 152   return err;
 153 }