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/* Copyright (C) 2017 Free Software Foundation, Inc.
Contributed by Agustina Arzille <avarzille@riseup.net>, 2017.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either
version 2 of the license, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public
License along with this program; if not, see
<http://www.gnu.org/licenses/>.
*/
#ifndef _KERN_ATOMIC_H_
#define _KERN_ATOMIC_H_ 1
/* Atomically compare *PTR with EXP and set it to NVAL if they're equal.
* Evaluates to a boolean, indicating whether the comparison was successful.*/
#define __atomic_cas_helper(ptr, exp, nval, mo) \
({ \
typeof(exp) __e = (exp); \
__atomic_compare_exchange_n ((ptr), &__e, (nval), 0, \
__ATOMIC_##mo, __ATOMIC_RELAXED); \
})
#define atomic_cas_acq(ptr, exp, nval) \
__atomic_cas_helper (ptr, exp, nval, ACQUIRE)
#define atomic_cas_rel(ptr, exp, nval) \
__atomic_cas_helper (ptr, exp, nval, RELEASE)
#define atomic_cas_seq(ptr, exp, nval) \
__atomic_cas_helper (ptr, exp, nval, SEQ_CST)
/* Atomically exchange the value of *PTR with VAL, evaluating to
* its previous value. */
#define __atomic_swap_helper(ptr, val, mo) \
__atomic_exchange_n ((ptr), (val), __ATOMIC_##mo)
#define atomic_swap_acq(ptr, val) \
__atomic_swap_helper (ptr, val, ACQUIRE)
#define atomic_swap_rel(ptr, val) \
__atomic_swap_helper (ptr, val, RELEASE)
#define atomic_swap_seq(ptr, val) \
__atomic_swap_helper (ptr, val, SEQ_CST)
#endif
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