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glibc  2.9
sem_post.c
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00001 /* sem_post -- post to a POSIX semaphore.  SPARC version.
00002    Copyright (C) 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004    Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
00005 
00006    The GNU C Library is free software; you can redistribute it and/or
00007    modify it under the terms of the GNU Lesser General Public
00008    License as published by the Free Software Foundation; either
00009    version 2.1 of the License, or (at your option) any later version.
00010 
00011    The GNU C Library is distributed in the hope that it will be useful,
00012    but WITHOUT ANY WARRANTY; without even the implied warranty of
00013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014    Lesser General Public License for more details.
00015 
00016    You should have received a copy of the GNU Lesser General Public
00017    License along with the GNU C Library; if not, write to the Free
00018    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00019    02111-1307 USA.  */
00020 
00021 #include <errno.h>
00022 #include <sysdep.h>
00023 #include <lowlevellock.h>
00024 #include <internaltypes.h>
00025 #include <semaphore.h>
00026 
00027 #include <shlib-compat.h>
00028 
00029 int
00030 __new_sem_post (sem_t *sem)
00031 {
00032   struct sparc_new_sem *isem = (struct sparc_new_sem *) sem;
00033   int nr;
00034 
00035   if (__atomic_is_v9)
00036     nr = atomic_increment_val (&isem->value);
00037   else
00038     {
00039       __sparc32_atomic_do_lock24 (&isem->lock);
00040       nr = ++(isem->value);
00041       __sparc32_atomic_do_unlock24 (&isem->lock);
00042     }
00043   atomic_full_barrier ();
00044   if (isem->nwaiters > 0)
00045     {
00046       int err = lll_futex_wake (&isem->value, 1,
00047                             isem->private ^ FUTEX_PRIVATE_FLAG);
00048       if (__builtin_expect (err, 0) < 0)
00049        {
00050          __set_errno (-err);
00051          return -1;
00052        }
00053     }
00054   return 0;
00055 }
00056 versioned_symbol (libpthread, __new_sem_post, sem_post, GLIBC_2_1);
00057 
00058 
00059 #if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1)
00060 int
00061 attribute_compat_text_section
00062 __old_sem_post (sem_t *sem)
00063 {
00064   struct sparc_old_sem *isem = (struct sparc_old_sem *) sem;
00065   int nr;
00066 
00067   if (__atomic_is_v9)
00068     nr = atomic_increment_val (&isem->value);
00069   else
00070     {
00071       __sparc32_atomic_do_lock24 (&isem->lock);
00072       nr = ++(isem->value);
00073       __sparc32_atomic_do_unlock24 (&isem->lock);
00074     }
00075   int err = lll_futex_wake (&isem->value, 1,
00076                          isem->private ^ FUTEX_PRIVATE_FLAG);
00077   if (__builtin_expect (err, 0) < 0)
00078     {
00079       __set_errno (-err);
00080       return -1;
00081     }
00082   return 0;
00083 }
00084 compat_symbol (libpthread, __old_sem_post, sem_post, GLIBC_2_0);
00085 #endif