mirror of git://sourceware.org/git/glibc.git
72 lines
2.0 KiB
C
72 lines
2.0 KiB
C
/* Copyright (C) 2003 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#ifndef _LOWLEVELSEM_H
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#define _LOWLEVELSEM_H 1
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#include <dl-sysdep.h>
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#include <tls.h>
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#include <lowlevellock.h>
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#include <semaphore.h>
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static inline int
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__attribute__ ((always_inline))
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lll_sem_wait (sem_t *sem)
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{
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int oldval;
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int newval;
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while (1)
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{
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/* Atomically decrement semaphore counter if it is > 0. */
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lll_compare_and_swap ((int *) sem, oldval, newval,
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"ltr %2,%1; jnp 1f; ahi %2,-1");
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/* oldval != newval if the semaphore count has been decremented. */
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if (oldval != newval)
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return 0;
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int err = lll_futex_wait ((int *) sem, 0);
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if (err != 0 && err != -EWOULDBLOCK)
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return -err;
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}
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return 0;
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}
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#if 0
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/* Not defined anywhere. */
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extern int __lll_sem_timedwait (sem_t *sem, const struct timespec *ts)
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attribute_hidden;
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#define lll_sem_timedwait(sem, timeout) \
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__lll_sem_timedwait (sem, timeout)
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#endif
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static inline void
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__attribute__ ((always_inline))
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lll_sem_post(sem_t *sem)
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{
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int oldval;
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int newval;
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lll_compare_and_swap ((int *) sem, oldval, newval, "lr %2,%1; ahi %2,1");
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lll_futex_wake ((int *) sem, newval);
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}
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#endif /* lowlevelsem.h */
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