bcachefs-tools/libbcachefs/two_state_shared_lock.h

29 lines
743 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_TWO_STATE_LOCK_H
#define _BCACHEFS_TWO_STATE_LOCK_H
#include <linux/atomic.h>
#include <linux/sched.h>
#include <linux/wait.h>
/*
* Two-state lock - can be taken for add or block - both states are shared,
* like read side of rwsem, but conflict with other state:
*/
typedef struct {
atomic_long_t v;
wait_queue_head_t wait;
} two_state_lock_t;
static inline void two_state_lock_init(two_state_lock_t *lock)
{
atomic_long_set(&lock->v, 0);
init_waitqueue_head(&lock->wait);
}
void bch2_two_state_unlock(two_state_lock_t *, int);
bool bch2_two_state_trylock(two_state_lock_t *, int);
void bch2_two_state_lock(two_state_lock_t *, int);
#endif /* _BCACHEFS_TWO_STATE_LOCK_H */