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/* Internal macros for atomic operations for GNU C Library.
Copyright (C) 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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 _ATOMIC_H
#define _ATOMIC_H 1
#include <stdlib.h>
#include <bits/atomic.h>
/* Wrapper macros to call pre_NN_post (mem, ...) where NN is the
bit width of *MEM. The calling macro puts parens around MEM
and following args. */
#define __atomic_val_bysize(pre, post, mem, ...) \
({ \
__typeof (*mem) __result; \
if (sizeof (*mem) == 1) \
__result = pre##_8_##post (mem, __VA_ARGS__); \
else if (sizeof (*mem) == 2) \
__result = pre##_16_##post (mem, __VA_ARGS__); \
else if (sizeof (*mem) == 4) \
__result = pre##_32_##post (mem, __VA_ARGS__); \
else if (sizeof (*mem) == 8) \
__result = pre##_64_##post (mem, __VA_ARGS__); \
else \
abort (); \
__result; \
})
#define __atomic_bool_bysize(pre, post, mem, ...) \
({ \
int __result; \
if (sizeof (*mem) == 1) \
__result = pre##_8_##post (mem, __VA_ARGS__); \
else if (sizeof (*mem) == 2) \
__result = pre##_16_##post (mem, __VA_ARGS__); \
else if (sizeof (*mem) == 4) \
__result = pre##_32_##post (mem, __VA_ARGS__); \
else if (sizeof (*mem) == 8) \
__result = pre##_64_##post (mem, __VA_ARGS__); \
else \
abort (); \
__result; \
})
/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL.
Return the old *MEM value. */
#if !defined atomic_compare_and_exchange_val_acq \
&& defined __arch_compare_and_exchange_val_32_acq
# define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
__atomic_val_bysize (__arch_compare_and_exchange_val,acq, \
(mem), (newval), (oldval))
#endif
#ifndef atomic_compare_and_exchange_val_rel
# define atomic_compare_and_exchange_val_rel(mem, oldval, newval) \
atomic_compare_and_exchange_val_acq ((mem), (oldval), (newval))
#endif
/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL.
Return zero if *MEM was changed or non-zero if no exchange happened. */
#ifndef atomic_compare_and_exchange_bool_acq
# ifdef __arch_compare_and_exchange_bool_32_acq
# define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
__atomic_bool_bysize (__arch_compare_and_exchange_bool,acq, \
(mem), (newval), (oldval))
# else
# define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
({ /* Cannot use __oldval here, because macros later in this file might \
call this macro with __oldval argument. */ \
__typeof (oldval) __old = (oldval); \
atomic_compare_and_exchange_val_acq ((mem), (newval), __old) != __old; \
})
# endif
#endif
#ifndef atomic_compare_and_exchange_bool_rel
# define atomic_compare_and_exchange_bool_rel(mem, oldval, newval) \
atomic_compare_and_exchange_bool_acq ((mem), (oldval), (newval))
#endif
/* Store NEWVALUE in *MEM and return the old value. */
#ifndef atomic_exchange
# define atomic_exchange(mem, newvalue) \
({ __typeof (*(mem)) __oldval; \
__typeof (mem) __memp = (mem); \
__typeof (*(mem)) __value = (newvalue); \
\
do \
__oldval = (*__memp); \
while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \
__value, \
__oldval),\
0)); \
\
__oldval; })
#endif
/* Add VALUE to *MEM and return the old value of *MEM. */
#ifndef atomic_exchange_and_add
# define atomic_exchange_and_add(mem, value) \
({ __typeof (*(mem)) __oldval; \
__typeof (mem) __memp = (mem); \
__typeof (*(mem)) __value = (value); \
\
do \
__oldval = (*__memp); \
while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \
__oldval \
+ __value,\
__oldval),\
0)); \
\
__oldval; })
#endif
#ifndef atomic_add
# define atomic_add(mem, value) (void) atomic_exchange_and_add ((mem), (value))
#endif
#ifndef atomic_increment
# define atomic_increment(mem) atomic_add ((mem), 1)
#endif
/* Add one to *MEM and return true iff it's now zero. */
#ifndef atomic_increment_and_test
# define atomic_increment_and_test(mem) \
(atomic_exchange_and_add ((mem), 1) + 1 == 0)
#endif
#ifndef atomic_decrement
# define atomic_decrement(mem) atomic_add ((mem), -1)
#endif
/* Subtract 1 from *MEM and return true iff it's now zero. */
#ifndef atomic_decrement_and_test
# define atomic_decrement_and_test(mem) \
(atomic_exchange_and_add ((mem), -1) == 1)
#endif
/* Decrement *MEM if it is > 0, and return the old value. */
#ifndef atomic_decrement_if_positive
# define atomic_decrement_if_positive(mem) \
({ __typeof (*(mem)) __oldval; \
__typeof (mem) __memp = (mem); \
\
do \
{ \
__oldval = *__memp; \
if (__builtin_expect (__oldval <= 0, 0)) \
break; \
} \
while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \
__oldval \
- 1, \
__oldval),\
0));\
__oldval; })
#endif
#ifndef atomic_add_negative
# define atomic_add_negative(mem, value) \
(atomic_exchange_and_add ((mem), (value)) < 0)
#endif
#ifndef atomic_add_zero
# define atomic_add_zero(mem, value) \
(atomic_exchange_and_add ((mem), (value)) == 0)
#endif
#ifndef atomic_bit_set
# define atomic_bit_set(mem, bit) \
(void) atomic_bit_test_set((mem), (bit))
#endif
#ifndef atomic_bit_test_set
# define atomic_bit_test_set(mem, bit) \
({ __typeof (*(mem)) __oldval; \
__typeof (mem) __memp = (mem); \
__typeof (*(mem)) __mask = ((__typeof (*(mem))) 1 << (bit)); \
\
do \
__oldval = (*__memp); \
while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \
__oldval \
| __mask, \
__oldval),\
0)); \
\
__oldval & __mask; })
#endif
#ifndef atomic_full_barrier
# define atomic_full_barrier() __asm ("" ::: "memory")
#endif
#ifndef atomic_read_barrier
# define atomic_read_barrier() atomic_full_barrier()
#endif
#ifndef atomic_write_barrier
# define atomic_write_barrier() atomic_full_barrier()
#endif
#endif /* atomic.h */
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