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/*-
* Copyright 2016 Vsevolod Stakhov
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef REF_H_
#define REF_H_
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
/**
* @file ref.h
* A set of macros to handle refcounts
*/
typedef void (*ref_dtor_cb_t)(void *data);
typedef struct ref_entry_s {
unsigned int refcount;
ref_dtor_cb_t dtor;
} ref_entry_t;
#define REF_INIT(obj, dtor_cb) do { \
if ((obj) != NULL) { \
(obj)->ref.refcount = 0; \
(obj)->ref.dtor = (ref_dtor_cb_t)(dtor_cb); \
} \
} while (0)
#define REF_INIT_RETAIN(obj, dtor_cb) do { \
if ((obj) != NULL) { \
(obj)->ref.refcount = 1; \
(obj)->ref.dtor = (ref_dtor_cb_t)(dtor_cb); \
} \
} while (0)
#ifdef HAVE_ATOMIC_BUILTINS
#define REF_RETAIN_ATOMIC(obj) do { \
if ((obj) != NULL) { \
__atomic_add_fetch (&(obj)->ref.refcount, 1, __ATOMIC_RELEASE); \
} \
} while (0)
#define REF_RELEASE_ATOMIC(obj) do { \
if ((obj) != NULL) { \
unsigned int _rc_priv = __atomic_sub_fetch (&(obj)->ref.refcount, 1, __ATOMIC_ACQ_REL); \
if (_rc_priv == 0 && (obj)->ref.dtor) { \
(obj)->ref.dtor (obj); \
} \
} \
} while (0)
#else
#define REF_RETAIN_ATOMIC REF_RETAIN
#define REF_RELEASE_ATOMIC REF_RELEASE_ATOMIC
#endif
#define REF_RETAIN(obj) do { \
if ((obj) != NULL) { \
(obj)->ref.refcount ++; \
} \
} while (0)
#define REF_RELEASE(obj) do { \
if ((obj) != NULL) { \
if (--(obj)->ref.refcount == 0 && (obj)->ref.dtor) { \
(obj)->ref.dtor (obj); \
} \
} \
} while (0)
#endif /* REF_H_ */
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