2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
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33 #ifndef _SYS__MUTEX_H_
34 #define _SYS__MUTEX_H_
36 #include <machine/param.h>
41 * All mutex implementations must always have a member called mtx_lock.
42 * Other locking primitive structures are not allowed to use this name
44 * If this rule needs to change, the bits in the mutex implementation must
45 * be modified appropriately.
48 struct lock_object lock_object; /* Common lock properties. */
49 volatile uintptr_t mtx_lock; /* Owner and flags. */
53 * Members of struct mtx_padalign must mirror members of struct mtx.
54 * mtx_padalign mutexes can use the mtx(9) API transparently without
56 * Pad-aligned mutexes used within structures should generally be the
57 * first member of the struct. Otherwise, the compiler can generate
58 * additional padding for the struct to keep a correct alignment for
62 struct lock_object lock_object; /* Common lock properties. */
63 volatile uintptr_t mtx_lock; /* Owner and flags. */
64 } __aligned(CACHE_LINE_SIZE);
66 #endif /* !_SYS__MUTEX_H_ */