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/*
* Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
* 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,
* 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.
* 3. Neither the name of Hyra nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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 _LIBC_LOCK_H
#define _LIBC_LOCK_H
#include <bits/_types.h>
typedef struct {
volatile __uint8_t lock;
} __libc_spinlock_t;
#if defined(__x86_64__)
__attribute__((__always_inline__, __weak__)) inline int
__test_and_set(__libc_spinlock_t *lock)
{
int tmp = 0;
__asm__ __volatile__(
"lock; cmpxchgb %b2, %0"
: "+m" (lock->lock), "+a" (tmp)
: "r" (1)
: "cc"
);
return tmp;
}
#else
#warn "Unimplemented arch"
#endif
#define __spinlock_def(NAME) __libc_spinlock_t NAME = {0};
#define __spinlock_acquire(LOCKPTR) while (__test_and_set(LOCKPTR))
#define __spinlock_release(LOCKPTR) ((LOCKPTR)->lock = 0)
#endif /* _LIBC_LOCK_H */
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