linux/include/linux/osq_lock.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_OSQ_LOCK_H
#define __LINUX_OSQ_LOCK_H

/*
 * An MCS like lock especially tailored for optimistic spinning for sleeping
 * lock implementations (mutex, rwsem, etc).
 */

struct optimistic_spin_queue { … };

#define OSQ_UNLOCKED_VAL …

/* Init macro and function. */
#define OSQ_LOCK_UNLOCKED …

static inline void osq_lock_init(struct optimistic_spin_queue *lock)
{ … }

extern bool osq_lock(struct optimistic_spin_queue *lock);
extern void osq_unlock(struct optimistic_spin_queue *lock);

static inline bool osq_is_locked(struct optimistic_spin_queue *lock)
{ … }

#endif