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/* Copyright (C) 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Martin Schwidefsky <schwidefsky@de.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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _LOWLEVELSEM_H
#define _LOWLEVELSEM_H 1
#include <dl-sysdep.h>
#include <tls.h>
#include <lowlevellock.h>
#include <semaphore.h>
static inline int
__attribute__ ((always_inline))
lll_sem_wait (sem_t *sem)
{
int oldval;
int newval;
while (1)
{
/* Atomically decrement semaphore counter if it is > 0. */
lll_compare_and_swap ((int *) sem, oldval, newval,
"ltr %2,%1; jnp 1f; ahi %2,-1");
/* oldval != newval if the semaphore count has been decremented. */
if (oldval != newval)
return 0;
int err = lll_futex_wait ((int *) sem, 0);
if (err != 0 && err != -EWOULDBLOCK)
return -err;
}
return 0;
}
#if 0
/* Not defined anywhere. */
extern int __lll_sem_timedwait (sem_t *sem, const struct timespec *ts)
attribute_hidden;
#define lll_sem_timedwait(sem, timeout) \
__lll_sem_timedwait (sem, timeout)
#endif
static inline void
__attribute__ ((always_inline))
lll_sem_post(sem_t *sem)
{
int oldval;
int newval;
lll_compare_and_swap ((int *) sem, oldval, newval, "lr %2,%1; ahi %2,1");
lll_futex_wake ((int *) sem, newval);
}
#endif /* lowlevelsem.h */
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