GIF89a;
Direktori : /lib/modules/3.10.0-957.21.3.el7.centos.plus.x86_64/source/include/linux/ |
Current File : //lib/modules/3.10.0-957.21.3.el7.centos.plus.x86_64/source/include/linux/refcount.h |
#ifndef _LINUX_REFCOUNT_H #define _LINUX_REFCOUNT_H #include <linux/atomic.h> #include <linux/mutex.h> #include <linux/spinlock.h> #include <linux/kernel.h> /** * refcount_t - variant of atomic_t specialized for reference counts * @refs: atomic_t counter field * * The counter saturates at UINT_MAX and will not move once * there. This avoids wrapping the counter and causing 'spurious' * use-after-free bugs. */ typedef struct refcount_struct { atomic_t refs; } refcount_t; #define REFCOUNT_INIT(n) { .refs = ATOMIC_INIT(n), } /** * refcount_set - set a refcount's value * @r: the refcount * @n: value to which the refcount will be set */ static inline void refcount_set(refcount_t *r, unsigned int n) { atomic_set(&r->refs, n); } /** * refcount_read - get a refcount's value * @r: the refcount * * Return: the refcount's value */ static inline unsigned int refcount_read(const refcount_t *r) { return atomic_read(&r->refs); } #ifdef CONFIG_REFCOUNT_FULL extern __must_check bool refcount_add_not_zero(unsigned int i, refcount_t *r); extern void refcount_add(unsigned int i, refcount_t *r); extern __must_check bool refcount_inc_not_zero(refcount_t *r); extern void refcount_inc(refcount_t *r); extern __must_check bool refcount_sub_and_test(unsigned int i, refcount_t *r); extern __must_check bool refcount_dec_and_test(refcount_t *r); extern void refcount_dec(refcount_t *r); #else static inline __must_check bool refcount_add_not_zero(unsigned int i, refcount_t *r) { return atomic_add_unless(&r->refs, i, 0); } static inline void refcount_add(unsigned int i, refcount_t *r) { atomic_add(i, &r->refs); } static inline __must_check bool refcount_inc_not_zero(refcount_t *r) { return atomic_add_unless(&r->refs, 1, 0); } static inline void refcount_inc(refcount_t *r) { atomic_inc(&r->refs); } static inline __must_check bool refcount_sub_and_test(unsigned int i, refcount_t *r) { return atomic_sub_and_test(i, &r->refs); } static inline __must_check bool refcount_dec_and_test(refcount_t *r) { return atomic_dec_and_test(&r->refs); } static inline void refcount_dec(refcount_t *r) { atomic_dec(&r->refs); } #endif /* CONFIG_REFCOUNT_FULL */ extern __must_check bool refcount_dec_if_one(refcount_t *r); extern __must_check bool refcount_dec_not_one(refcount_t *r); extern __must_check bool refcount_dec_and_mutex_lock(refcount_t *r, struct mutex *lock); extern __must_check bool refcount_dec_and_lock(refcount_t *r, spinlock_t *lock); #endif /* _LINUX_REFCOUNT_H */