kref: Implement 'struct kref' using refcount_t (10383aea) · Commits · 戴 / test

include/linux/kref.h

+11 −18

Original line number	Diff line number	Diff line
		@@ -15,17 +15,14 @@
		#ifndef _KREF_H_
		#define _KREF_H_

		#include <linux/bug.h>
		#include <linux/atomic.h>
		#include <linux/kernel.h>
		#include <linux/mutex.h>
		#include <linux/spinlock.h>
		#include <linux/refcount.h>

		struct kref {
		atomic_t refcount;
		refcount_t refcount;
		};

		#define KREF_INIT(n) { .refcount = ATOMIC_INIT(n), }
		#define KREF_INIT(n) { .refcount = REFCOUNT_INIT(n), }

		/**
		* kref_init - initialize object.
		@@ -33,12 +30,12 @@ struct kref {
		*/
		static inline void kref_init(struct kref *kref)
		{
		atomic_set(&kref->refcount, 1);
		refcount_set(&kref->refcount, 1);
		}

		static inline int kref_read(const struct kref *kref)
		static inline unsigned int kref_read(const struct kref *kref)
		{
		return atomic_read(&kref->refcount);
		return refcount_read(&kref->refcount);
		}

		/**
		@@ -47,11 +44,7 @@ static inline int kref_read(const struct kref *kref)
		*/
		static inline void kref_get(struct kref *kref)
		{
		/* If refcount was 0 before incrementing then we have a race
		* condition when this kref is freeing by some other thread right now.
		* In this case one should use kref_get_unless_zero()
		*/
		WARN_ON_ONCE(atomic_inc_return(&kref->refcount) < 2);
		refcount_inc(&kref->refcount);
		}

		/**
		@@ -75,7 +68,7 @@ static inline int kref_put(struct kref kref, void (release)(struct kref *kref)
		{
		WARN_ON(release == NULL);

		if (atomic_dec_and_test(&kref->refcount)) {
		if (refcount_dec_and_test(&kref->refcount)) {
		release(kref);
		return 1;
		}
		@@ -88,7 +81,7 @@ static inline int kref_put_mutex(struct kref *kref,
		{
		WARN_ON(release == NULL);

		if (atomic_dec_and_mutex_lock(&kref->refcount, lock)) {
		if (refcount_dec_and_mutex_lock(&kref->refcount, lock)) {
		release(kref);
		return 1;
		}
		@@ -101,7 +94,7 @@ static inline int kref_put_lock(struct kref *kref,
		{
		WARN_ON(release == NULL);

		if (atomic_dec_and_lock(&kref->refcount, lock)) {
		if (refcount_dec_and_lock(&kref->refcount, lock)) {
		release(kref);
		return 1;
		}
		@@ -126,6 +119,6 @@ static inline int kref_put_lock(struct kref *kref,
		*/
		static inline int __must_check kref_get_unless_zero(struct kref *kref)
		{
		return atomic_add_unless(&kref->refcount, 1, 0);
		return refcount_inc_not_zero(&kref->refcount);
		}
		#endif /* _KREF_H_ */

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