hb-object-private.hh revision c605bbbb6d4b2a98b1f40ca818760088d991f7d1 
1/*
2 * Copyright © 2007  Chris Wilson
3 * Copyright © 2009,2010  Red Hat, Inc.
4 * Copyright © 2011  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-mutex-private.hh"
38
39
40
41/* Debug */
42
43#ifndef HB_DEBUG_OBJECT
44#define HB_DEBUG_OBJECT (HB_DEBUG+0)
45#endif
46
47
48/* atomic_int */
49
50/* We need external help for these */
51
52#ifdef HAVE_GLIB
53
54#include <glib.h>
55
56typedef volatile int hb_atomic_int_t;
57#define hb_atomic_int_fetch_and_add(AI, V)	g_atomic_int_exchange_and_add (&(AI), V)
58#define hb_atomic_int_get(AI)			g_atomic_int_get (&(AI))
59#define hb_atomic_int_set(AI, V)		g_atomic_int_set (&(AI), V)
60
61
62#elif defined(_MSC_VER)
63
64#include <intrin.h>
65
66typedef long hb_atomic_int_t;
67#define hb_atomic_int_fetch_and_add(AI, V)	_InterlockedExchangeAdd (&(AI), V)
68#define hb_atomic_int_get(AI)			(_ReadBarrier (), (AI))
69#define hb_atomic_int_set(AI, V)		((void) _InterlockedExchange (&(AI), (V)))
70
71
72#else
73
74#warning "Could not find any system to define atomic_int macros, library will NOT be thread-safe"
75
76typedef volatile int hb_atomic_int_t;
77#define hb_atomic_int_fetch_and_add(AI, V)	((AI) += (V), (AI) - (V))
78#define hb_atomic_int_get(AI)			(AI)
79#define hb_atomic_int_set(AI, V)		((void) ((AI) = (V)))
80
81
82#endif
83
84
85
86
87/* reference_count */
88
89typedef struct {
90  hb_atomic_int_t ref_count;
91
92#define HB_REFERENCE_COUNT_INVALID_VALUE ((hb_atomic_int_t) -1)
93#define HB_REFERENCE_COUNT_INVALID {HB_REFERENCE_COUNT_INVALID_VALUE}
94
95  inline void init (int v) { ref_count = v; /* non-atomic is fine */ }
96  inline int inc (void) { return hb_atomic_int_fetch_and_add (ref_count,  1); }
97  inline int dec (void) { return hb_atomic_int_fetch_and_add (ref_count, -1); }
98  inline void set (int v) { hb_atomic_int_set (ref_count, v); }
99
100  inline int get (void) const { return hb_atomic_int_get (ref_count); }
101  inline bool is_invalid (void) const { return get () == HB_REFERENCE_COUNT_INVALID_VALUE; }
102
103} hb_reference_count_t;
104
105
106/* user_data */
107
108struct hb_user_data_array_t {
109
110  struct hb_user_data_item_t {
111    hb_user_data_key_t *key;
112    void *data;
113    hb_destroy_func_t destroy;
114
115    inline bool operator == (hb_user_data_key_t *other_key) const { return key == other_key; }
116    inline bool operator == (hb_user_data_item_t &other) const { return key == other.key; }
117
118    void finish (void) { if (destroy) destroy (data); }
119  };
120
121  hb_lockable_set_t<hb_user_data_item_t, hb_static_mutex_t> items;
122
123  HB_INTERNAL bool set (hb_user_data_key_t *key,
124			void *              data,
125			hb_destroy_func_t   destroy);
126
127  HB_INTERNAL void *get (hb_user_data_key_t *key);
128
129  HB_INTERNAL void finish (void);
130};
131
132
133/* object_header */
134
135typedef struct _hb_object_header_t hb_object_header_t;
136
137struct _hb_object_header_t {
138  hb_reference_count_t ref_count;
139  hb_user_data_array_t user_data;
140
141#define HB_OBJECT_HEADER_STATIC {HB_REFERENCE_COUNT_INVALID}
142
143  static inline void *create (unsigned int size) {
144    hb_object_header_t *obj = (hb_object_header_t *) calloc (1, size);
145
146    if (likely (obj))
147      obj->init ();
148
149    return obj;
150  }
151
152  inline void init (void) {
153    ref_count.init (1);
154  }
155
156  inline bool is_inert (void) const {
157    return unlikely (ref_count.is_invalid ());
158  }
159
160  inline void reference (void) {
161    if (unlikely (!this || this->is_inert ()))
162      return;
163    ref_count.inc ();
164  }
165
166  inline bool destroy (void) {
167    if (unlikely (!this || this->is_inert ()))
168      return false;
169    if (ref_count.dec () != 1)
170      return false;
171
172    ref_count.init (HB_REFERENCE_COUNT_INVALID_VALUE);
173
174    user_data.finish ();
175
176    return true;
177  }
178
179  inline bool set_user_data (hb_user_data_key_t *key,
180			     void *              data,
181			     hb_destroy_func_t   destroy_func) {
182    if (unlikely (!this || this->is_inert ()))
183      return false;
184
185    return user_data.set (key, data, destroy_func);
186  }
187
188  inline void *get_user_data (hb_user_data_key_t *key) {
189    return user_data.get (key);
190  }
191
192  inline void trace (const char *function) const {
193    DEBUG_MSG (OBJECT, (void *) this,
194	       "refcount=%d %s",
195	       this ? ref_count.get () : 0,
196	       function);
197  }
198
199};
200
201
202
203
204/* object */
205
206template <typename Type>
207static inline void hb_object_trace (const Type *obj, const char *function)
208{
209  obj->header.trace (function);
210}
211template <typename Type>
212static inline Type *hb_object_create (void)
213{
214  Type *obj = (Type *) hb_object_header_t::create (sizeof (Type));
215  hb_object_trace (obj, HB_FUNC);
216  return obj;
217}
218template <typename Type>
219static inline bool hb_object_is_inert (const Type *obj)
220{
221  return unlikely (obj->header.is_inert ());
222}
223template <typename Type>
224static inline Type *hb_object_reference (Type *obj)
225{
226  hb_object_trace (obj, HB_FUNC);
227  obj->header.reference ();
228  return obj;
229}
230template <typename Type>
231static inline bool hb_object_destroy (Type *obj)
232{
233  hb_object_trace (obj, HB_FUNC);
234  return obj->header.destroy ();
235}
236template <typename Type>
237static inline bool hb_object_set_user_data (Type               *obj,
238					    hb_user_data_key_t *key,
239					    void *              data,
240					    hb_destroy_func_t   destroy)
241{
242  return obj->header.set_user_data (key, data, destroy);
243}
244
245template <typename Type>
246static inline void *hb_object_get_user_data (Type               *obj,
247					     hb_user_data_key_t *key)
248{
249  return obj->header.get_user_data (key);
250}
251
252
253
254
255
256#endif /* HB_OBJECT_PRIVATE_HH */
257