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/*
* Copyright (c) 2006-2023, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2022-3-1 zhouxiaohu first version
* 2023-5-18 GuEe-GUI implemented by rtatomic
*/
#ifndef __UTIL_REF_H__
#define __UTIL_REF_H__
#include <rtatomic.h>
/**
* struct ref must be embedded in an object.
* it acts as a reference counter for the object.
*/
struct rt_ref
{
rt_atomic_t refcount;
};
#define RT_REF_INIT(n) { .refcount = n, }
rt_inline void rt_ref_init(struct rt_ref *r)
{
rt_atomic_store(&r->refcount, 1);
}
rt_inline unsigned int rt_ref_read(struct rt_ref *r)
{
return rt_atomic_load(&r->refcount);
}
/**
* ref_get
* increment reference counter for object.
*/
rt_inline void rt_ref_get(struct rt_ref *r)
{
rt_atomic_add(&r->refcount, 1);
}
/**
* ref_put
* decrement reference counter for object.
* If the reference counter is zero, call release().
*
* Return 1 means the object's reference counter is zero and release() is called.
*/
rt_inline int rt_ref_put(struct rt_ref *r, void (*release)(struct rt_ref *r))
{
if (rt_atomic_dec_and_test(&r->refcount))
{
release(r);
return 1;
}
return 0;
}
/**
* ref_get_unless_zero - Increment refcount for object unless it is zero.
* Return non-zero if the increment succeeded. Otherwise return 0.
*/
rt_inline int rt_ref_get_unless_zero(struct rt_ref *r)
{
return (int)rt_atomic_inc_not_zero(&r->refcount);
}
#endif /* __UTIL_REF_H__ */
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