1/*
2 * Copyright © 2007  Chris Wilson
3 * Copyright © 2009,2010  Red Hat, Inc.
4 * Copyright © 2011,2012  Google, Inc.
5 *
6 *  This is part of HarfBuzz, a text shaping library.
7 *
8 * Permission is hereby granted, without written agreement and without
9 * license or royalty fees, to use, copy, modify, and distribute this
10 * software and its documentation for any purpose, provided that the
11 * above copyright notice and the following two paragraphs appear in
12 * all copies of this software.
13 *
14 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
15 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
17 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18 * DAMAGE.
19 *
20 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
21 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
22 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
23 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
24 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 *
26 * Contributor(s):
27 *	Chris Wilson <chris@chris-wilson.co.uk>
28 * Red Hat Author(s): Behdad Esfahbod
29 * Google Author(s): Behdad Esfahbod
30 */
31
32#ifndef HB_OBJECT_PRIVATE_HH
33#define HB_OBJECT_PRIVATE_HH
34
35#include "hb-private.hh"
36
37#include "hb-atomic-private.hh"
38#include "hb-mutex-private.hh"
39
40
41/* Debug */
42
43#ifndef HB_DEBUG_OBJECT
44#define HB_DEBUG_OBJECT (HB_DEBUG+0)
45#endif
46
47
48/* reference_count */
49
50#define HB_REFERENCE_COUNT_INVALID_VALUE ((hb_atomic_int_t) -1)
51#define HB_REFERENCE_COUNT_INVALID {HB_REFERENCE_COUNT_INVALID_VALUE}
52struct hb_reference_count_t
53{
54  hb_atomic_int_t ref_count;
55
56  inline void init (int v) { ref_count = v; }
57  inline int inc (void) { return hb_atomic_int_add (const_cast<hb_atomic_int_t &> (ref_count),  1); }
58  inline int dec (void) { return hb_atomic_int_add (const_cast<hb_atomic_int_t &> (ref_count), -1); }
59  inline void finish (void) { ref_count = HB_REFERENCE_COUNT_INVALID_VALUE; }
60
61  inline bool is_invalid (void) const { return ref_count == HB_REFERENCE_COUNT_INVALID_VALUE; }
62
63};
64
65
66/* user_data */
67
68#define HB_USER_DATA_ARRAY_INIT {HB_MUTEX_INIT, HB_LOCKABLE_SET_INIT}
69struct hb_user_data_array_t
70{
71  struct hb_user_data_item_t {
72    hb_user_data_key_t *key;
73    void *data;
74    hb_destroy_func_t destroy;
75
76    inline bool operator == (hb_user_data_key_t *other_key) const { return key == other_key; }
77    inline bool operator == (hb_user_data_item_t &other) const { return key == other.key; }
78
79    void finish (void) { if (destroy) destroy (data); }
80  };
81
82  hb_mutex_t lock;
83  hb_lockable_set_t<hb_user_data_item_t, hb_mutex_t> items;
84
85  inline void init (void) { lock.init (); items.init (); }
86
87  HB_INTERNAL bool set (hb_user_data_key_t *key,
88			void *              data,
89			hb_destroy_func_t   destroy,
90			hb_bool_t           replace);
91
92  HB_INTERNAL void *get (hb_user_data_key_t *key);
93
94  inline void finish (void) { items.finish (lock); lock.finish (); }
95};
96
97
98/* object_header */
99
100struct hb_object_header_t
101{
102  hb_reference_count_t ref_count;
103  hb_user_data_array_t user_data;
104
105#define HB_OBJECT_HEADER_STATIC {HB_REFERENCE_COUNT_INVALID, HB_USER_DATA_ARRAY_INIT}
106
107  private:
108  ASSERT_POD ();
109};
110
111
112/* object */
113
114template <typename Type>
115static inline void hb_object_trace (const Type *obj, const char *function)
116{
117  DEBUG_MSG (OBJECT, (void *) obj,
118	     "%s refcount=%d",
119	     function,
120	     obj ? obj->header.ref_count.ref_count : 0);
121}
122
123template <typename Type>
124static inline Type *hb_object_create (void)
125{
126  Type *obj = (Type *) calloc (1, sizeof (Type));
127
128  if (unlikely (!obj))
129    return obj;
130
131  hb_object_init (obj);
132  hb_object_trace (obj, HB_FUNC);
133  return obj;
134}
135template <typename Type>
136static inline void hb_object_init (Type *obj)
137{
138  obj->header.ref_count.init (1);
139  obj->header.user_data.init ();
140}
141template <typename Type>
142static inline bool hb_object_is_inert (const Type *obj)
143{
144  return unlikely (obj->header.ref_count.is_invalid ());
145}
146template <typename Type>
147static inline Type *hb_object_reference (Type *obj)
148{
149  hb_object_trace (obj, HB_FUNC);
150  if (unlikely (!obj || hb_object_is_inert (obj)))
151    return obj;
152  obj->header.ref_count.inc ();
153  return obj;
154}
155template <typename Type>
156static inline bool hb_object_destroy (Type *obj)
157{
158  hb_object_trace (obj, HB_FUNC);
159  if (unlikely (!obj || hb_object_is_inert (obj)))
160    return false;
161  if (obj->header.ref_count.dec () != 1)
162    return false;
163
164  obj->header.ref_count.finish (); /* Do this before user_data */
165  obj->header.user_data.finish ();
166  return true;
167}
168template <typename Type>
169static inline bool hb_object_set_user_data (Type               *obj,
170					    hb_user_data_key_t *key,
171					    void *              data,
172					    hb_destroy_func_t   destroy,
173					    hb_bool_t           replace)
174{
175  if (unlikely (!obj || hb_object_is_inert (obj)))
176    return false;
177  return obj->header.user_data.set (key, data, destroy, replace);
178}
179
180template <typename Type>
181static inline void *hb_object_get_user_data (Type               *obj,
182					     hb_user_data_key_t *key)
183{
184  if (unlikely (!obj || hb_object_is_inert (obj)))
185    return NULL;
186  return obj->header.user_data.get (key);
187}
188
189
190#endif /* HB_OBJECT_PRIVATE_HH */
191