hb-object-private.hh revision 31f18abecb149f8888a72510f2660328dd6de16d 
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
39HB_BEGIN_DECLS
40
41
42/* Debug */
43
44#ifndef HB_DEBUG_OBJECT
45#define HB_DEBUG_OBJECT (HB_DEBUG+0)
46#endif
47
48
49/* atomic_int */
50
51/* We need external help for these */
52
53#ifdef HAVE_GLIB
54
55#include <glib.h>
56
57typedef volatile int hb_atomic_int_t;
58#define hb_atomic_int_fetch_and_add(AI, V)	g_atomic_int_exchange_and_add (&(AI), V)
59#define hb_atomic_int_get(AI)			g_atomic_int_get (&(AI))
60#define hb_atomic_int_set(AI, V)		g_atomic_int_set (&(AI), V)
61
62
63#elif defined(_MSC_VER)
64
65#include <intrin.h>
66
67typedef long hb_atomic_int_t;
68#define hb_atomic_int_fetch_and_add(AI, V)	_InterlockedExchangeAdd (&(AI), V)
69#define hb_atomic_int_get(AI)			(_ReadBarrier (), (AI))
70#define hb_atomic_int_set(AI, V)		((void) _InterlockedExchange (&(AI), (V)))
71
72
73#else
74
75#warning "Could not find any system to define atomic_int macros, library will NOT be thread-safe"
76
77typedef volatile int hb_atomic_int_t;
78#define hb_atomic_int_fetch_and_add(AI, V)	((AI) += (V), (AI) - (V))
79#define hb_atomic_int_get(AI)			(AI)
80#define hb_atomic_int_set(AI, V)		((void) ((AI) = (V)))
81
82
83#endif
84
85
86
87
88/* reference_count */
89
90typedef struct {
91  hb_atomic_int_t ref_count;
92
93#define HB_REFERENCE_COUNT_INVALID_VALUE ((hb_atomic_int_t) -1)
94#define HB_REFERENCE_COUNT_INVALID {HB_REFERENCE_COUNT_INVALID_VALUE}
95
96  inline void init (int v) { ref_count = v; /* non-atomic is fine */ }
97  inline int inc (void) { return hb_atomic_int_fetch_and_add (ref_count,  1); }
98  inline int dec (void) { return hb_atomic_int_fetch_and_add (ref_count, -1); }
99  inline void set (int v) { hb_atomic_int_set (ref_count, v); }
100
101  inline int get (void) const { return hb_atomic_int_get (ref_count); }
102  inline bool is_invalid (void) const { return get () == HB_REFERENCE_COUNT_INVALID_VALUE; }
103
104} hb_reference_count_t;
105
106
107/* user_data */
108
109struct hb_user_data_array_t {
110
111  struct hb_user_data_item_t {
112    hb_user_data_key_t *key;
113    void *data;
114    hb_destroy_func_t destroy;
115
116    inline bool operator == (hb_user_data_key_t *other_key) const { return key == other_key; }
117    inline bool operator == (hb_user_data_item_t &other) const { return key == other.key; }
118
119    void finish (void) { if (destroy) destroy (data); }
120  };
121
122  hb_lockable_set_t<hb_user_data_item_t, hb_static_mutex_t> items;
123
124  HB_INTERNAL bool set (hb_user_data_key_t *key,
125			void *              data,
126			hb_destroy_func_t   destroy);
127
128  HB_INTERNAL void *get (hb_user_data_key_t *key);
129
130  HB_INTERNAL void finish (void);
131};
132
133
134/* object_header */
135
136typedef struct _hb_object_header_t hb_object_header_t;
137
138struct _hb_object_header_t {
139  hb_reference_count_t ref_count;
140  hb_user_data_array_t user_data;
141
142#define HB_OBJECT_HEADER_STATIC {HB_REFERENCE_COUNT_INVALID}
143
144  static inline void *create (unsigned int size) {
145    hb_object_header_t *obj = (hb_object_header_t *) calloc (1, size);
146
147    if (likely (obj))
148      obj->init ();
149
150    return obj;
151  }
152
153  inline void init (void) {
154    ref_count.init (1);
155  }
156
157  inline bool is_inert (void) const {
158    return unlikely (ref_count.is_invalid ());
159  }
160
161  inline void reference (void) {
162    if (unlikely (!this || this->is_inert ()))
163      return;
164    ref_count.inc ();
165  }
166
167  inline bool destroy (void) {
168    if (unlikely (!this || this->is_inert ()))
169      return false;
170    if (ref_count.dec () != 1)
171      return false;
172
173    ref_count.init (HB_REFERENCE_COUNT_INVALID_VALUE);
174
175    user_data.finish ();
176
177    return true;
178  }
179
180  inline bool set_user_data (hb_user_data_key_t *key,
181			     void *              data,
182			     hb_destroy_func_t   destroy_func) {
183    if (unlikely (!this || this->is_inert ()))
184      return false;
185
186    return user_data.set (key, data, destroy_func);
187  }
188
189  inline void *get_user_data (hb_user_data_key_t *key) {
190    return user_data.get (key);
191  }
192
193  inline void trace (const char *function) const {
194    (void) (HB_DEBUG_OBJECT &&
195	    fprintf (stderr, "OBJECT(%p) refcount=%d %s\n",
196		     (void *) this,
197		     this ? ref_count.get () : 0,
198		     function));
199  }
200
201};
202
203
204HB_END_DECLS
205
206
207/* object */
208
209template <typename Type>
210static inline void hb_object_trace (const Type *obj, const char *function)
211{
212  obj->header.trace (function);
213}
214template <typename Type>
215static inline Type *hb_object_create (void)
216{
217  Type *obj = (Type *) hb_object_header_t::create (sizeof (Type));
218  hb_object_trace (obj, HB_FUNC);
219  return obj;
220}
221template <typename Type>
222static inline bool hb_object_is_inert (const Type *obj)
223{
224  return unlikely (obj->header.is_inert ());
225}
226template <typename Type>
227static inline Type *hb_object_reference (Type *obj)
228{
229  hb_object_trace (obj, HB_FUNC);
230  obj->header.reference ();
231  return obj;
232}
233template <typename Type>
234static inline bool hb_object_destroy (Type *obj)
235{
236  hb_object_trace (obj, HB_FUNC);
237  return obj->header.destroy ();
238}
239template <typename Type>
240static inline bool hb_object_set_user_data (Type               *obj,
241					    hb_user_data_key_t *key,
242					    void *              data,
243					    hb_destroy_func_t   destroy)
244{
245  return obj->header.set_user_data (key, data, destroy);
246}
247
248template <typename Type>
249static inline void *hb_object_get_user_data (Type               *obj,
250					     hb_user_data_key_t *key)
251{
252  return obj->header.get_user_data (key);
253}
254
255
256HB_BEGIN_DECLS
257
258
259HB_END_DECLS
260
261#endif /* HB_OBJECT_PRIVATE_HH */
262