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 #include "hb-debug.hh"
37
38 #include "hb-atomic-private.hh"
39 #include "hb-mutex-private.hh"
40
41
42 /* reference_count */
43
44 #define HB_REFERENCE_COUNT_INERT_VALUE -1
45 #define HB_REFERENCE_COUNT_POISON_VALUE -0x0000DEAD
46 #define HB_REFERENCE_COUNT_INIT {HB_ATOMIC_INT_INIT(HB_REFERENCE_COUNT_INERT_VALUE)}
47
48 struct hb_reference_count_t
49 {
50 hb_atomic_int_t ref_count;
51
52 inline void init (int v) { ref_count.set_unsafe (v); }
53 inline int get_unsafe (void) const { return ref_count.get_unsafe (); }
54 inline int inc (void) { return ref_count.inc (); }
55 inline int dec (void) { return ref_count.dec (); }
56 inline void finish (void) { ref_count.set_unsafe (HB_REFERENCE_COUNT_POISON_VALUE); }
57
58 inline bool is_inert (void) const { return ref_count.get_unsafe () == HB_REFERENCE_COUNT_INERT_VALUE; }
59 inline bool is_valid (void) const { return ref_count.get_unsafe () > 0; }
60 };
61
62
63 /* user_data */
64
65 #define HB_USER_DATA_ARRAY_INIT {HB_MUTEX_INIT, HB_LOCKABLE_SET_INIT}
66 struct hb_user_data_array_t
67 {
68 struct hb_user_data_item_t {
69 hb_user_data_key_t *key;
70 void *data;
71 hb_destroy_func_t destroy;
72
73 inline bool operator == (hb_user_data_key_t *other_key) const { return key == other_key; }
74 inline bool operator == (hb_user_data_item_t &other) const { return key == other.key; }
75
76 void finish (void) { if (destroy) destroy (data); }
77 };
78
79 hb_mutex_t lock;
80 hb_lockable_set_t<hb_user_data_item_t, hb_mutex_t> items;
81
82 inline void init (void) { lock.init (); items.init (); }
83
84 HB_INTERNAL bool set (hb_user_data_key_t *key,
85 void * data,
86 hb_destroy_func_t destroy,
87 hb_bool_t replace);
88
89 HB_INTERNAL void *get (hb_user_data_key_t *key);
90
91 inline void finish (void) { items.finish (lock); lock.finish (); }
92 };
93
94
95 /* object_header */
96
97 struct hb_object_header_t
98 {
99 hb_reference_count_t ref_count;
100 hb_user_data_array_t user_data;
101
102 #define HB_OBJECT_HEADER_STATIC {HB_REFERENCE_COUNT_INIT, HB_USER_DATA_ARRAY_INIT}
103
104 private:
105 ASSERT_POD ();
106 };
107
108
109 /* object */
110
111 template <typename Type>
112 static inline void hb_object_trace (const Type *obj, const char *function)
113 {
114 DEBUG_MSG (OBJECT, (void *) obj,
115 "%s refcount=%d",
116 function,
117 obj ? obj->header.ref_count.get_unsafe () : 0);
118 }
119
120 template <typename Type>
121 static inline Type *hb_object_create (void)
122 {
123 Type *obj = (Type *) calloc (1, sizeof (Type));
124
125 if (unlikely (!obj))
126 return obj;
127
128 hb_object_init (obj);
129 hb_object_trace (obj, HB_FUNC);
130 return obj;
131 }
132 template <typename Type>
133 static inline void hb_object_init (Type *obj)
134 {
135 obj->header.ref_count.init (1);
136 obj->header.user_data.init ();
137 }
138 template <typename Type>
139 static inline bool hb_object_is_inert (const Type *obj)
140 {
141 return unlikely (obj->header.ref_count.is_inert ());
142 }
143 template <typename Type>
144 static inline bool hb_object_is_valid (const Type *obj)
145 {
146 return likely (obj->header.ref_count.is_valid ());
147 }
148 template <typename Type>
149 static inline Type *hb_object_reference (Type *obj)
150 {
151 hb_object_trace (obj, HB_FUNC);
152 if (unlikely (!obj || hb_object_is_inert (obj)))
153 return obj;
154 assert (hb_object_is_valid (obj));
155 obj->header.ref_count.inc ();
156 return obj;
157 }
158 template <typename Type>
159 static inline bool hb_object_destroy (Type *obj)
160 {
161 hb_object_trace (obj, HB_FUNC);
162 if (unlikely (!obj || hb_object_is_inert (obj)))
163 return false;
164 assert (hb_object_is_valid (obj));
165 if (obj->header.ref_count.dec () != 1)
166 return false;
167
168 obj->header.ref_count.finish (); /* Do this before user_data */
169 obj->header.user_data.finish ();
170 return true;
171 }
172 template <typename Type>
173 static inline bool hb_object_set_user_data (Type *obj,
174 hb_user_data_key_t *key,
175 void * data,
176 hb_destroy_func_t destroy,
177 hb_bool_t replace)
178 {
179 if (unlikely (!obj || hb_object_is_inert (obj)))
180 return false;
181 assert (hb_object_is_valid (obj));
182 return obj->header.user_data.set (key, data, destroy, replace);
183 }
184
185 template <typename Type>
186 static inline void *hb_object_get_user_data (Type *obj,
187 hb_user_data_key_t *key)
188 {
189 if (unlikely (!obj || hb_object_is_inert (obj)))
190 return nullptr;
191 assert (hb_object_is_valid (obj));
192 return obj->header.user_data.get (key);
193 }
194
195
196 #endif /* HB_OBJECT_PRIVATE_HH */