root / lab4 / .minix-src / include / sys / common_lock.h @ 13
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/* $NetBSD: common_lock.h,v 1.1 2015/06/26 14:27:35 matt Exp $ */
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/*-
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* Copyright (c) 2014 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Matt Thomas of 3am Software Foundry.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Machine-dependent spin lock operations using the builtin compiler atomic
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* primitives.
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*/
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#ifndef _SYS_COMMON_LOCK_H_
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#define _SYS_COMMON_LOCK_H_
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static __inline int |
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__SIMPLELOCK_LOCKED_P(__cpu_simple_lock_t *__ptr) |
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{
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return *__ptr != __SIMPLELOCK_UNLOCKED;
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} |
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static __inline int |
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__SIMPLELOCK_UNLOCKED_P(__cpu_simple_lock_t *__ptr) |
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{
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return *__ptr == __SIMPLELOCK_UNLOCKED;
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} |
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static __inline void |
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__cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr) |
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{
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#if 1 |
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*__ptr = __SIMPLELOCK_UNLOCKED; |
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#else
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__atomic_store_n(__ptr, __SIMPLELOCK_UNLOCKED, __ATOMIC_RELAXED); |
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#endif
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} |
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static __inline void |
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__cpu_simple_lock_set(__cpu_simple_lock_t *__ptr) |
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{
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#if 1 |
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*__ptr = __SIMPLELOCK_LOCKED; |
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#else
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__atomic_store_n(__ptr, __SIMPLELOCK_LOCKED, __ATOMIC_RELAXED); |
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#endif
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} |
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static __inline void __unused |
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__cpu_simple_lock_init(__cpu_simple_lock_t *__ptr) |
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{
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#if 1 |
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*__ptr = __SIMPLELOCK_UNLOCKED; |
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#else
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__atomic_store_n(__ptr, __SIMPLELOCK_UNLOCKED, __ATOMIC_RELAXED); |
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#endif
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} |
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static __inline void __unused |
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__cpu_simple_lock(__cpu_simple_lock_t *__ptr) |
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{
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while (__atomic_exchange_n(__ptr, __SIMPLELOCK_LOCKED, __ATOMIC_ACQUIRE) == __SIMPLELOCK_LOCKED) {
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/* do nothing */
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} |
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} |
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static __inline int __unused |
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__cpu_simple_lock_try(__cpu_simple_lock_t *__ptr) |
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{
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return __atomic_exchange_n(__ptr, __SIMPLELOCK_LOCKED, __ATOMIC_ACQUIRE) == __SIMPLELOCK_UNLOCKED;
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} |
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static __inline void __unused |
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__cpu_simple_unlock(__cpu_simple_lock_t *__ptr) |
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{
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__atomic_store_n(__ptr, __SIMPLELOCK_UNLOCKED, __ATOMIC_RELEASE); |
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} |
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#endif /* _SYS_COMMON_LOCK_H_ */ |