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zig/lib/libc/include/generic-freebsd/sys/rangelock.h
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2025-12-07 09:32:28 +01:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2009 Konstantin Belousov <kib@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _SYS_RANGELOCK_H
#define _SYS_RANGELOCK_H
#include <sys/types.h>
#ifndef _KERNEL
#include <stdbool.h>
#endif
#define RL_LOCK_READ 0x0001
#define RL_LOCK_WRITE 0x0002
#define RL_LOCK_TYPE_MASK 0x0003
struct rl_q_entry;
/*
* The structure representing the range lock. Caller may request
* read or write access to the range of bytes. Access is granted if
* all existing lock owners are compatible with the request. Two lock
* owners are compatible if their ranges do not overlap, or both
* owners are for read.
*/
struct rangelock {
uintptr_t head;
bool sleepers;
};
#ifdef _KERNEL
void rangelock_init(struct rangelock *lock);
void rangelock_destroy(struct rangelock *lock);
void rangelock_unlock(struct rangelock *lock, void *cookie);
void *rangelock_rlock(struct rangelock *lock, vm_ooffset_t start,
vm_ooffset_t end);
void *rangelock_tryrlock(struct rangelock *lock, vm_ooffset_t start,
vm_ooffset_t end);
void *rangelock_wlock(struct rangelock *lock, vm_ooffset_t start,
vm_ooffset_t end);
void *rangelock_trywlock(struct rangelock *lock, vm_ooffset_t start,
vm_ooffset_t end);
void rangelock_may_recurse(struct rangelock *lock);
#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
void _rangelock_cookie_assert(void *cookie, int what, const char *file,
int line);
#endif
#ifdef INVARIANTS
#define rangelock_cookie_assert_(cookie, what, file, line) \
_rangelock_cookie_assert((cookie), (what), (file), (line))
#else
#define rangelock_cookie_assert_(cookie, what, file, line) (void)0
#endif
#define rangelock_cookie_assert(cookie, what) \
rangelock_cookie_assert_((cookie), (what), __FILE__, __LINE__)
/*
* Assertion flags.
*/
#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
#define RCA_LOCKED 0x0001
#define RCA_RLOCKED 0x0002
#define RCA_WLOCKED 0x0004
#endif
#endif /* _KERNEL */
#endif /* _SYS_RANGELOCK_H */