/*
* Copyright (C) 2007 Chris Wilson
* Copyright (C) 2009 Red Hat, Inc.
*
* This is part of HarfBuzz, an OpenType Layout engine library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Contributor(s):
* Chris Wilson <chris@chris-wilson.co.uk>
* Red Hat Author(s): Behdad Esfahbod
*/
#ifndef HB_REFCOUNT_PRIVATE_H
#define HB_REFCOUNT_PRIVATE_H
typedef int hb_atomic_int_t;
/* Encapsulate operations on the object's reference count */
typedef struct {
hb_atomic_int_t ref_count;
} hb_reference_count_t;
/* XXX add real atomic ops */
#define _hb_reference_count_inc(RC) ((RC).ref_count++)
#define _hb_reference_count_dec_and_test(RC) ((RC).ref_count-- == 1)
#define HB_REFERENCE_COUNT_INIT(RC, VALUE) ((RC).ref_count = (VALUE))
#define HB_REFERENCE_COUNT_GET_VALUE(RC) ((RC).ref_count+0)
#define HB_REFERENCE_COUNT_SET_VALUE(RC, VALUE) ((RC).ref_count = (VALUE), 0)
#define HB_REFERENCE_COUNT_INVALID_VALUE ((hb_atomic_int_t) -1)
#define HB_REFERENCE_COUNT_INVALID {HB_REFERENCE_COUNT_INVALID_VALUE}
#define HB_REFERENCE_COUNT_IS_INVALID(RC) (HB_REFERENCE_COUNT_GET_VALUE (RC) == HB_REFERENCE_COUNT_INVALID_VALUE)
#define HB_REFERENCE_COUNT_HAS_REFERENCE(RC) (HB_REFERENCE_COUNT_GET_VALUE (RC) > 0)
/* Helper macros */
#define HB_OBJECT_IS_INERT(obj) \
((obj) == NULL || HB_REFERENCE_COUNT_IS_INVALID ((obj)->ref_count))
#define HB_OBJECT_DO_INIT_EXPR(obj) \
HB_REFERENCE_COUNT_INIT (obj->ref_count, 1)
#define HB_OBJECT_DO_INIT(obj) \
HB_STMT_START { \
HB_OBJECT_DO_INIT_EXPR (obj); \
} HB_STMT_END
#define HB_OBJECT_DO_CREATE(obj) \
HB_LIKELY (( \
(obj) = calloc (1, sizeof (*(obj))), \
HB_OBJECT_DO_INIT_EXPR (obj), \
(obj) \
))
#define HB_OBJECT_DO_REFERENCE(obj) \
HB_STMT_START { \
if (HB_OBJECT_IS_INERT (obj)) \
return obj; \
assert (HB_REFERENCE_COUNT_HAS_REFERENCE (obj->ref_count)); \
_hb_reference_count_inc (obj->ref_count); \
return obj; \
} HB_STMT_END
#define HB_OBJECT_DO_GET_REFERENCE_COUNT(obj) \
HB_STMT_START { \
if (HB_OBJECT_IS_INERT (obj)) \
return 0; \
return HB_REFERENCE_COUNT_GET_VALUE (obj->ref_count); \
} HB_STMT_END
#define HB_OBJECT_DO_DESTROY(obj) \
HB_STMT_START { \
if (HB_OBJECT_IS_INERT (obj)) \
return; \
assert (HB_REFERENCE_COUNT_HAS_REFERENCE (obj->ref_count)); \
if (!_hb_reference_count_dec_and_test (obj->ref_count)) \
return; \
} HB_STMT_END
#endif /* HB_REFCOUNT_PRIVATE_H */
