glibc/nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c
2012-02-09 23:18:22 +00:00

72 lines
2.1 KiB
C

/* sem_post -- post to a POSIX semaphore. Powerpc version.
Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <sysdep.h>
#include <lowlevellock.h>
#include <internaltypes.h>
#include <semaphore.h>
#include <shlib-compat.h>
int
__new_sem_post (sem_t *sem)
{
struct new_sem *isem = (struct new_sem *) sem;
__asm __volatile (__lll_rel_instr ::: "memory");
atomic_increment (&isem->value);
__asm __volatile (__lll_acq_instr ::: "memory");
if (isem->nwaiters > 0)
{
int err = lll_futex_wake (&isem->value, 1,
isem->private ^ FUTEX_PRIVATE_FLAG);
if (__builtin_expect (err, 0) < 0)
{
__set_errno (-err);
return -1;
}
}
return 0;
}
versioned_symbol (libpthread, __new_sem_post, sem_post, GLIBC_2_1);
#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1)
int
attribute_compat_text_section
__old_sem_post (sem_t *sem)
{
int *futex = (int *) sem;
__asm __volatile (__lll_rel_instr ::: "memory");
int nr = atomic_increment_val (futex);
/* We always have to assume it is a shared semaphore. */
int err = lll_futex_wake (futex, 1, LLL_SHARED);
if (__builtin_expect (err, 0) < 0)
{
__set_errno (-err);
return -1;
}
return 0;
}
compat_symbol (libpthread, __old_sem_post, sem_post, GLIBC_2_0);
#endif