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_HH
33 #define HB_OBJECT_HH
34
35 #include "hb.hh"
36 #include "hb-atomic.hh"
37 #include "hb-mutex.hh"
38 #include "hb-vector.hh"
39
40
41 /*
42 * Lockable set
43 */
44
45 template <typename item_t, typename lock_t>
46 struct hb_lockable_set_t
47 {
48 hb_vector_t<item_t> items;
49
inithb_lockable_set_t50 void init () { items.init (); }
51
52 template <typename T>
replace_or_inserthb_lockable_set_t53 item_t *replace_or_insert (T v, lock_t &l, bool replace)
54 {
55 l.lock ();
56 item_t *item = items.find (v);
57 if (item) {
58 if (replace) {
59 item_t old = *item;
60 *item = v;
61 l.unlock ();
62 old.fini ();
63 }
64 else {
65 item = nullptr;
66 l.unlock ();
67 }
68 } else {
69 item = items.push (v);
70 l.unlock ();
71 }
72 return item;
73 }
74
75 template <typename T>
removehb_lockable_set_t76 void remove (T v, lock_t &l)
77 {
78 l.lock ();
79 item_t *item = items.find (v);
80 if (item)
81 {
82 item_t old = *item;
83 *item = items[items.length - 1];
84 items.pop ();
85 l.unlock ();
86 old.fini ();
87 } else {
88 l.unlock ();
89 }
90 }
91
92 template <typename T>
findhb_lockable_set_t93 bool find (T v, item_t *i, lock_t &l)
94 {
95 l.lock ();
96 item_t *item = items.find (v);
97 if (item)
98 *i = *item;
99 l.unlock ();
100 return !!item;
101 }
102
103 template <typename T>
find_or_inserthb_lockable_set_t104 item_t *find_or_insert (T v, lock_t &l)
105 {
106 l.lock ();
107 item_t *item = items.find (v);
108 if (!item) {
109 item = items.push (v);
110 }
111 l.unlock ();
112 return item;
113 }
114
finihb_lockable_set_t115 void fini (lock_t &l)
116 {
117 if (!items.length)
118 {
119 /* No need to lock. */
120 items.fini ();
121 return;
122 }
123 l.lock ();
124 while (items.length)
125 {
126 item_t old = items[items.length - 1];
127 items.pop ();
128 l.unlock ();
129 old.fini ();
130 l.lock ();
131 }
132 items.fini ();
133 l.unlock ();
134 }
135
136 };
137
138
139 /*
140 * Reference-count.
141 */
142
143 #define HB_REFERENCE_COUNT_INIT {0}
144
145 struct hb_reference_count_t
146 {
147 mutable hb_atomic_int_t ref_count;
148
inithb_reference_count_t149 void init (int v = 1) { ref_count.set_relaxed (v); }
get_relaxedhb_reference_count_t150 int get_relaxed () const { return ref_count.get_relaxed (); }
inchb_reference_count_t151 int inc () const { return ref_count.inc (); }
dechb_reference_count_t152 int dec () const { return ref_count.dec (); }
finihb_reference_count_t153 void fini () { ref_count.set_relaxed (-0x0000DEAD); }
154
is_inerthb_reference_count_t155 bool is_inert () const { return !ref_count.get_relaxed (); }
is_validhb_reference_count_t156 bool is_valid () const { return ref_count.get_relaxed () > 0; }
157 };
158
159
160 /* user_data */
161
162 struct hb_user_data_array_t
163 {
164 struct hb_user_data_item_t {
165 hb_user_data_key_t *key;
166 void *data;
167 hb_destroy_func_t destroy;
168
operator ==hb_user_data_array_t::hb_user_data_item_t169 bool operator == (const hb_user_data_key_t *other_key) const { return key == other_key; }
operator ==hb_user_data_array_t::hb_user_data_item_t170 bool operator == (const hb_user_data_item_t &other) const { return key == other.key; }
171
finihb_user_data_array_t::hb_user_data_item_t172 void fini () { if (destroy) destroy (data); }
173 };
174
175 hb_mutex_t lock;
176 hb_lockable_set_t<hb_user_data_item_t, hb_mutex_t> items;
177
inithb_user_data_array_t178 void init () { lock.init (); items.init (); }
179
180 HB_INTERNAL bool set (hb_user_data_key_t *key,
181 void * data,
182 hb_destroy_func_t destroy,
183 hb_bool_t replace);
184
185 HB_INTERNAL void *get (hb_user_data_key_t *key);
186
finihb_user_data_array_t187 void fini () { items.fini (lock); lock.fini (); }
188 };
189
190
191 /*
192 * Object header
193 */
194
195 struct hb_object_header_t
196 {
197 hb_reference_count_t ref_count;
198 mutable hb_atomic_int_t writable = 0;
199 hb_atomic_ptr_t<hb_user_data_array_t> user_data;
200 };
201 #define HB_OBJECT_HEADER_STATIC {}
202
203
204 /*
205 * Object
206 */
207
208 template <typename Type>
hb_object_trace(const Type * obj,const char * function)209 static inline void hb_object_trace (const Type *obj, const char *function)
210 {
211 DEBUG_MSG (OBJECT, (void *) obj,
212 "%s refcount=%d",
213 function,
214 obj ? obj->header.ref_count.get_relaxed () : 0);
215 }
216
217 template <typename Type>
hb_object_create()218 static inline Type *hb_object_create ()
219 {
220 Type *obj = (Type *) calloc (1, sizeof (Type));
221
222 if (unlikely (!obj))
223 return obj;
224
225 hb_object_init (obj);
226 hb_object_trace (obj, HB_FUNC);
227 return obj;
228 }
229 template <typename Type>
hb_object_init(Type * obj)230 static inline void hb_object_init (Type *obj)
231 {
232 obj->header.ref_count.init ();
233 obj->header.writable.set_relaxed (true);
234 obj->header.user_data.init ();
235 }
236 template <typename Type>
hb_object_is_inert(const Type * obj)237 static inline bool hb_object_is_inert (const Type *obj)
238 {
239 return unlikely (obj->header.ref_count.is_inert ());
240 }
241 template <typename Type>
hb_object_is_valid(const Type * obj)242 static inline bool hb_object_is_valid (const Type *obj)
243 {
244 return likely (obj->header.ref_count.is_valid ());
245 }
246 template <typename Type>
hb_object_is_immutable(const Type * obj)247 static inline bool hb_object_is_immutable (const Type *obj)
248 {
249 return !obj->header.writable.get_relaxed ();
250 }
251 template <typename Type>
hb_object_make_immutable(const Type * obj)252 static inline void hb_object_make_immutable (const Type *obj)
253 {
254 obj->header.writable.set_relaxed (false);
255 }
256 template <typename Type>
hb_object_reference(Type * obj)257 static inline Type *hb_object_reference (Type *obj)
258 {
259 hb_object_trace (obj, HB_FUNC);
260 if (unlikely (!obj || hb_object_is_inert (obj)))
261 return obj;
262 assert (hb_object_is_valid (obj));
263 obj->header.ref_count.inc ();
264 return obj;
265 }
266 template <typename Type>
hb_object_destroy(Type * obj)267 static inline bool hb_object_destroy (Type *obj)
268 {
269 hb_object_trace (obj, HB_FUNC);
270 if (unlikely (!obj || hb_object_is_inert (obj)))
271 return false;
272 assert (hb_object_is_valid (obj));
273 if (obj->header.ref_count.dec () != 1)
274 return false;
275
276 hb_object_fini (obj);
277 return true;
278 }
279 template <typename Type>
hb_object_fini(Type * obj)280 static inline void hb_object_fini (Type *obj)
281 {
282 obj->header.ref_count.fini (); /* Do this before user_data */
283 hb_user_data_array_t *user_data = obj->header.user_data.get ();
284 if (user_data)
285 {
286 user_data->fini ();
287 free (user_data);
288 user_data = nullptr;
289 }
290 }
291 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)292 static inline bool hb_object_set_user_data (Type *obj,
293 hb_user_data_key_t *key,
294 void * data,
295 hb_destroy_func_t destroy,
296 hb_bool_t replace)
297 {
298 if (unlikely (!obj || hb_object_is_inert (obj)))
299 return false;
300 assert (hb_object_is_valid (obj));
301
302 retry:
303 hb_user_data_array_t *user_data = obj->header.user_data.get ();
304 if (unlikely (!user_data))
305 {
306 user_data = (hb_user_data_array_t *) calloc (sizeof (hb_user_data_array_t), 1);
307 if (unlikely (!user_data))
308 return false;
309 user_data->init ();
310 if (unlikely (!obj->header.user_data.cmpexch (nullptr, user_data)))
311 {
312 user_data->fini ();
313 free (user_data);
314 goto retry;
315 }
316 }
317
318 return user_data->set (key, data, destroy, replace);
319 }
320
321 template <typename Type>
hb_object_get_user_data(Type * obj,hb_user_data_key_t * key)322 static inline void *hb_object_get_user_data (Type *obj,
323 hb_user_data_key_t *key)
324 {
325 if (unlikely (!obj || hb_object_is_inert (obj)))
326 return nullptr;
327 assert (hb_object_is_valid (obj));
328 hb_user_data_array_t *user_data = obj->header.user_data.get ();
329 if (!user_data)
330 return nullptr;
331 return user_data->get (key);
332 }
333
334
335 #endif /* HB_OBJECT_HH */
336