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}
52 struct hb_reference_count_t
53 {
54   hb_atomic_int_t ref_count;
55 
inithb_reference_count_t56   inline void init (int v) { ref_count = v; }
inchb_reference_count_t57   inline int inc (void) { return hb_atomic_int_add (const_cast<hb_atomic_int_t &> (ref_count),  1); }
dechb_reference_count_t58   inline int dec (void) { return hb_atomic_int_add (const_cast<hb_atomic_int_t &> (ref_count), -1); }
finishhb_reference_count_t59   inline void finish (void) { ref_count = HB_REFERENCE_COUNT_INVALID_VALUE; }
60 
is_invalidhb_reference_count_t61   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}
69 struct 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 
operator ==hb_user_data_array_t::hb_user_data_item_t76     inline bool operator == (hb_user_data_key_t *other_key) const { return key == other_key; }
operator ==hb_user_data_array_t::hb_user_data_item_t77     inline bool operator == (hb_user_data_item_t &other) const { return key == other.key; }
78 
finishhb_user_data_array_t::hb_user_data_item_t79     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 
inithb_user_data_array_t85   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 
finishhb_user_data_array_t94   inline void finish (void) { items.finish (lock); lock.finish (); }
95 };
96 
97 
98 /* object_header */
99 
100 struct 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 
114 template <typename Type>
hb_object_trace(const Type * obj,const char * function)115 static 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 
123 template <typename Type>
hb_object_create(void)124 static 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 }
135 template <typename Type>
hb_object_init(Type * obj)136 static inline void hb_object_init (Type *obj)
137 {
138   obj->header.ref_count.init (1);
139   obj->header.user_data.init ();
140 }
141 template <typename Type>
hb_object_is_inert(const Type * obj)142 static inline bool hb_object_is_inert (const Type *obj)
143 {
144   return unlikely (obj->header.ref_count.is_invalid ());
145 }
146 template <typename Type>
hb_object_reference(Type * obj)147 static 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 }
155 template <typename Type>
hb_object_destroy(Type * obj)156 static 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 }
168 template <typename Type>
hb_object_set_user_data(Type * obj,hb_user_data_key_t * key,void * data,hb_destroy_func_t destroy,hb_bool_t replace)169 static 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 
180 template <typename Type>
hb_object_get_user_data(Type * obj,hb_user_data_key_t * key)181 static 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