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/* Copyright (c) 2014, Vsevolod Stakhov
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef REF_H_
#define REF_H_
/**
* @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 { \
(obj)->ref.refcount = 0; \
(obj)->ref.dtor = (ref_dtor_cb_t)(dtor_cb); \
} while (0)
#define REF_INIT_RETAIN(obj, dtor_cb) do { \
(obj)->ref.refcount = 1; \
(obj)->ref.dtor = (ref_dtor_cb_t)(dtor_cb); \
} while (0)
#ifdef HAVE_ATOMIC_BUILTINS
#define REF_RETAIN(obj) do { \
__sync_add_and_fetch (&(obj)->ref.refcount, 1); \
} while (0)
#define REF_RELEASE(obj) do { \
unsigned int rc = __sync_sub_and_fetch (&(obj)->ref.refcount, 1); \
if (rc == 0 && (obj)->ref.dtor) { \
(obj)->ref.dtor (obj); \
} \
} while (0)
#else
#define REF_RETAIN(obj) do { \
(obj)->ref.refcount ++; \
} while (0)
#define REF_RELEASE(obj) do { \
if (--(obj)->ref.refcount == 0 && (obj)->ref.dtor) { \
(obj)->ref.dtor (obj); \
} \
} while (0)
#endif
#endif /* REF_H_ */
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