hb-object-private.hh revision d5476a30a10da5e54783c8dbf04340225a9a00d7 
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#if GLIB_CHECK_VERSION(2,29,5)
58#define hb_atomic_int_add(AI, V)	g_atomic_int_add (&(AI), V)
59#else
60#define hb_atomic_int_add(AI, V)	g_atomic_int_exchange_and_add (&(AI), V)
61#endif
62#define hb_atomic_int_get(AI)		g_atomic_int_get (&(AI))
63#define hb_atomic_int_set(AI, V)	g_atomic_int_set (&(AI), V)
64
65
66#elif defined(_MSC_VER)
67
68#include <intrin.h>
69
70typedef long hb_atomic_int_t;
71#define hb_atomic_int_add(AI, V)	_InterlockedExchangeAdd (&(AI), V)
72#define hb_atomic_int_get(AI)		(_ReadBarrier (), (AI))
73#define hb_atomic_int_set(AI, V)	((void) _InterlockedExchange (&(AI), (V)))
74
75
76#else
77
78#warning "Could not find any system to define atomic_int macros, library will NOT be thread-safe"
79
80typedef volatile int hb_atomic_int_t;
81#define hb_atomic_int_add(AI, V)	((AI) += (V), (AI) - (V))
82#define hb_atomic_int_get(AI)		(AI)
83#define hb_atomic_int_set(AI, V)	((void) ((AI) = (V)))
84
85
86#endif
87
88
89
90
91/* reference_count */
92
93typedef struct {
94  hb_atomic_int_t ref_count;
95
96#define HB_REFERENCE_COUNT_INVALID_VALUE ((hb_atomic_int_t) -1)
97#define HB_REFERENCE_COUNT_INVALID {HB_REFERENCE_COUNT_INVALID_VALUE}
98
99  inline void init (int v) { ref_count = v; /* non-atomic is fine */ }
100  inline int inc (void) { return hb_atomic_int_add (ref_count,  1); }
101  inline int dec (void) { return hb_atomic_int_add (ref_count, -1); }
102  inline void set (int v) { hb_atomic_int_set (ref_count, v); }
103
104  inline int get (void) const { return hb_atomic_int_get (ref_count); }
105  inline bool is_invalid (void) const { return get () == HB_REFERENCE_COUNT_INVALID_VALUE; }
106
107} hb_reference_count_t;
108
109
110/* user_data */
111
112struct hb_user_data_array_t {
113
114  struct hb_user_data_item_t {
115    hb_user_data_key_t *key;
116    void *data;
117    hb_destroy_func_t destroy;
118
119    inline bool operator == (hb_user_data_key_t *other_key) const { return key == other_key; }
120    inline bool operator == (hb_user_data_item_t &other) const { return key == other.key; }
121
122    void finish (void) { if (destroy) destroy (data); }
123  };
124
125  hb_lockable_set_t<hb_user_data_item_t, hb_static_mutex_t> items;
126
127  HB_INTERNAL bool set (hb_user_data_key_t *key,
128			void *              data,
129			hb_destroy_func_t   destroy,
130			hb_bool_t           replace);
131
132  HB_INTERNAL void *get (hb_user_data_key_t *key);
133
134  HB_INTERNAL void finish (void);
135};
136
137
138/* object_header */
139
140typedef struct _hb_object_header_t hb_object_header_t;
141
142struct _hb_object_header_t {
143  hb_reference_count_t ref_count;
144  hb_user_data_array_t user_data;
145
146#define HB_OBJECT_HEADER_STATIC {HB_REFERENCE_COUNT_INVALID}
147
148  static inline void *create (unsigned int size) {
149    hb_object_header_t *obj = (hb_object_header_t *) calloc (1, size);
150
151    if (likely (obj))
152      obj->init ();
153
154    return obj;
155  }
156
157  inline void init (void) {
158    ref_count.init (1);
159  }
160
161  inline bool is_inert (void) const {
162    return unlikely (ref_count.is_invalid ());
163  }
164
165  inline void reference (void) {
166    if (unlikely (!this || this->is_inert ()))
167      return;
168    ref_count.inc ();
169  }
170
171  inline bool destroy (void) {
172    if (unlikely (!this || this->is_inert ()))
173      return false;
174    if (ref_count.dec () != 1)
175      return false;
176
177    ref_count.init (HB_REFERENCE_COUNT_INVALID_VALUE);
178
179    user_data.finish ();
180
181    return true;
182  }
183
184  inline bool set_user_data (hb_user_data_key_t *key,
185			     void *              data,
186			     hb_destroy_func_t   destroy_func,
187			     hb_bool_t           replace) {
188    if (unlikely (!this || this->is_inert ()))
189      return false;
190
191    return user_data.set (key, data, destroy_func, replace);
192  }
193
194  inline void *get_user_data (hb_user_data_key_t *key) {
195    return user_data.get (key);
196  }
197
198  inline void trace (const char *function) const {
199    DEBUG_MSG (OBJECT, (void *) this,
200	       "refcount=%d %s",
201	       this ? ref_count.get () : 0,
202	       function);
203  }
204
205};
206
207
208
209
210/* object */
211
212template <typename Type>
213static inline void hb_object_trace (const Type *obj, const char *function)
214{
215  obj->header.trace (function);
216}
217template <typename Type>
218static inline Type *hb_object_create (void)
219{
220  Type *obj = (Type *) hb_object_header_t::create (sizeof (Type));
221  hb_object_trace (obj, HB_FUNC);
222  return obj;
223}
224template <typename Type>
225static inline bool hb_object_is_inert (const Type *obj)
226{
227  return unlikely (obj->header.is_inert ());
228}
229template <typename Type>
230static inline Type *hb_object_reference (Type *obj)
231{
232  hb_object_trace (obj, HB_FUNC);
233  obj->header.reference ();
234  return obj;
235}
236template <typename Type>
237static inline bool hb_object_destroy (Type *obj)
238{
239  hb_object_trace (obj, HB_FUNC);
240  return obj->header.destroy ();
241}
242template <typename Type>
243static inline bool hb_object_set_user_data (Type               *obj,
244					    hb_user_data_key_t *key,
245					    void *              data,
246					    hb_destroy_func_t   destroy,
247					    hb_bool_t           replace)
248{
249  return obj->header.set_user_data (key, data, destroy, replace);
250}
251
252template <typename Type>
253static inline void *hb_object_get_user_data (Type               *obj,
254					     hb_user_data_key_t *key)
255{
256  return obj->header.get_user_data (key);
257}
258
259
260
261
262
263#endif /* HB_OBJECT_PRIVATE_HH */
264