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/* POSIX spinlock implementation. AM33 version.
Copyright 2001-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <pthread.h>
#include "internals.h"
int
__pthread_spin_lock (pthread_spinlock_t *lock)
{
__asm__ __volatile__("1: bset %1, (%0); beq 1b"
: : "a" (lock), "d" (1) : "memory");
return 0;
}
weak_alias (__pthread_spin_lock, pthread_spin_lock)
int
__pthread_spin_trylock (pthread_spinlock_t *lock)
{
int oldval = 1;
__asm__ __volatile__ ("bset %0, (%1); beq 1f; clr %0; 1:" :
"+d" (oldval) : "a" (lock) : "memory");
return oldval ? EBUSY : 0;
}
weak_alias (__pthread_spin_trylock, pthread_spin_trylock)
int
__pthread_spin_unlock (pthread_spinlock_t *lock)
{
*lock = 0;
return 0;
}
weak_alias (__pthread_spin_unlock, pthread_spin_unlock)
int
__pthread_spin_init (pthread_spinlock_t *lock, int pshared)
{
/* We can ignore the `pshared' parameter. Since we are busy-waiting
all processes which can access the memory location `lock' points
to can use the spinlock. */
*lock = 0;
return 0;
}
weak_alias (__pthread_spin_init, pthread_spin_init)
int
__pthread_spin_destroy (pthread_spinlock_t *lock)
{
/* Nothing to do. */
return 0;
}
weak_alias (__pthread_spin_destroy, pthread_spin_destroy)
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