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
45template <typename item_t, typename lock_t>
46struct hb_lockable_set_t
47{
48 hb_vector_t <item_t, 1> items;
49
50 inline void init (void) { items.init (); }
51
52 template <typename T>
53 inline 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>
76 inline void remove (T v, lock_t &l)
77 {
78 l.lock ();
79 item_t *item = items.find (v);
80 if (item) {
81 item_t old = *item;
82 *item = items[items.len - 1];
83 items.pop ();
84 l.unlock ();
85 old.fini ();
86 } else {
87 l.unlock ();
88 }
89 }
90
91 template <typename T>
92 inline bool find (T v, item_t *i, lock_t &l)
93 {
94 l.lock ();
95 item_t *item = items.find (v);
96 if (item)
97 *i = *item;
98 l.unlock ();
99 return !!item;
100 }
101
102 template <typename T>
103 inline item_t *find_or_insert (T v, lock_t &l)
104 {
105 l.lock ();
106 item_t *item = items.find (v);
107 if (!item) {
108 item = items.push (v);
109 }
110 l.unlock ();
111 return item;
112 }
113
114 inline void fini (lock_t &l)
115 {
116 if (!items.len) {
117 /* No need for locking. */
118 items.fini ();
119 return;
120 }
121 l.lock ();
122 while (items.len) {
123 item_t old = items[items.len - 1];
124 items.pop ();
125 l.unlock ();
126 old.fini ();
127 l.lock ();
128 }
129 items.fini ();
130 l.unlock ();
131 }
132
133};
134
135
136/*
137 * Reference-count.
138 */
139
140#define HB_REFERENCE_COUNT_INERT_VALUE 0
141#define HB_REFERENCE_COUNT_POISON_VALUE -0x0000DEAD
142#define HB_REFERENCE_COUNT_INIT {HB_ATOMIC_INT_INIT (HB_REFERENCE_COUNT_INERT_VALUE)}
143
144struct hb_reference_count_t
145{
146 mutable hb_atomic_int_t ref_count;
147
148 inline void init (int v = 1) { ref_count.set_relaxed (v); }
149 inline int get_relaxed (void) const { return ref_count.get_relaxed (); }
150 inline int inc (void) const { return ref_count.inc (); }
151 inline int dec (void) const { return ref_count.dec (); }
152 inline void fini (void) { ref_count.set_relaxed (HB_REFERENCE_COUNT_POISON_VALUE); }
153
154 inline bool is_inert (void) const { return ref_count.get_relaxed () == HB_REFERENCE_COUNT_INERT_VALUE; }
155 inline bool is_valid (void) const { return ref_count.get_relaxed () > 0; }
156};
157
158
159/* user_data */
160
161struct hb_user_data_array_t
162{
163 struct hb_user_data_item_t {
164 hb_user_data_key_t *key;
165 void *data;
166 hb_destroy_func_t destroy;
167
168 inline bool operator == (hb_user_data_key_t *other_key) const { return key == other_key; }
169 inline bool operator == (hb_user_data_item_t &other) const { return key == other.key; }
170
171 void fini (void) { if (destroy) destroy (data); }
172 };
173
174 hb_mutex_t lock;
175 hb_lockable_set_t<hb_user_data_item_t, hb_mutex_t> items;
176
177 inline void init (void) { lock.init (); items.init (); }
178
179 HB_INTERNAL bool set (hb_user_data_key_t *key,
180 void * data,
181 hb_destroy_func_t destroy,
182 hb_bool_t replace);
183
184 HB_INTERNAL void *get (hb_user_data_key_t *key);
185
186 inline void fini (void) { items.fini (lock); lock.fini (); }
187};
188
189
190/*
191 * Object header
192 */
193
194struct hb_object_header_t
195{
196 hb_reference_count_t ref_count;
197 hb_atomic_ptr_t<hb_user_data_array_t> user_data;
198
199#define HB_OBJECT_HEADER_STATIC {HB_REFERENCE_COUNT_INIT, HB_ATOMIC_PTR_INIT (nullptr)}
200
201 private:
202 ASSERT_POD ();
203};
204
205
206/*
207 * Object
208 */
209
210template <typename Type>
211static inline void hb_object_trace (const Type *obj, const char *function)
212{
213 DEBUG_MSG (OBJECT, (void *) obj,
214 "%s refcount=%d",
215 function,
216 obj ? obj->header.ref_count.get_relaxed () : 0);
217}
218
219template <typename Type>
220static inline Type *hb_object_create (void)
221{
222 Type *obj = (Type *) calloc (1, sizeof (Type));
223
224 if (unlikely (!obj))
225 return obj;
226
227 hb_object_init (obj);
228 hb_object_trace (obj, HB_FUNC);
229 return obj;
230}
231template <typename Type>
232static inline void hb_object_init (Type *obj)
233{
234 obj->header.ref_count.init ();
235 obj->header.user_data.init ();
236}
237template <typename Type>
238static inline bool hb_object_is_inert (const Type *obj)
239{
240 return unlikely (obj->header.ref_count.is_inert ());
241}
242template <typename Type>
243static inline bool hb_object_is_valid (const Type *obj)
244{
245 return likely (obj->header.ref_count.is_valid ());
246}
247template <typename Type>
248static inline Type *hb_object_reference (Type *obj)
249{
250 hb_object_trace (obj, HB_FUNC);
251 if (unlikely (!obj || hb_object_is_inert (obj)))
252 return obj;
253 assert (hb_object_is_valid (obj));
254 obj->header.ref_count.inc ();
255 return obj;
256}
257template <typename Type>
258static inline bool hb_object_destroy (Type *obj)
259{
260 hb_object_trace (obj, HB_FUNC);
261 if (unlikely (!obj || hb_object_is_inert (obj)))
262 return false;
263 assert (hb_object_is_valid (obj));
264 if (obj->header.ref_count.dec () != 1)
265 return false;
266
267 hb_object_fini (obj);
268 return true;
269}
270template <typename Type>
271static inline void hb_object_fini (Type *obj)
272{
273 obj->header.ref_count.fini (); /* Do this before user_data */
274 hb_user_data_array_t *user_data = obj->header.user_data.get ();
275 if (user_data)
276 {
277 user_data->fini ();
278 free (user_data);
279 }
280}
281template <typename Type>
282static inline bool hb_object_set_user_data (Type *obj,
283 hb_user_data_key_t *key,
284 void * data,
285 hb_destroy_func_t destroy,
286 hb_bool_t replace)
287{
288 if (unlikely (!obj || hb_object_is_inert (obj)))
289 return false;
290 assert (hb_object_is_valid (obj));
291
292retry:
293 hb_user_data_array_t *user_data = obj->header.user_data.get ();
294 if (unlikely (!user_data))
295 {
296 user_data = (hb_user_data_array_t *) calloc (sizeof (hb_user_data_array_t), 1);
297 if (unlikely (!user_data))
298 return false;
299 user_data->init ();
300 if (unlikely (!obj->header.user_data.cmpexch (nullptr, user_data)))
301 {
302 user_data->fini ();
303 free (user_data);
304 goto retry;
305 }
306 }
307
308 return user_data->set (key, data, destroy, replace);
309}
310
311template <typename Type>
312static inline void *hb_object_get_user_data (Type *obj,
313 hb_user_data_key_t *key)
314{
315 if (unlikely (!obj || hb_object_is_inert (obj)))
316 return nullptr;
317 assert (hb_object_is_valid (obj));
318 hb_user_data_array_t *user_data = obj->header.user_data.get ();
319 if (!user_data)
320 return nullptr;
321 return user_data->get (key);
322}
323
324
325#endif /* HB_OBJECT_HH */
326