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