hb-object-private.hh revision 218e67b9eefa26e2e4fe43f99a84d082b185b1b0 
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
37HB_BEGIN_DECLS
38
39
40/* Debug */
41
42#ifndef HB_DEBUG_OBJECT
43#define HB_DEBUG_OBJECT (HB_DEBUG+0)
44#endif
45
46
47/* atomic_int */
48
49/* We need external help for these */
50
51#ifdef HAVE_GLIB
52
53#include <glib.h>
54
55typedef volatile int hb_atomic_int_t;
56#define hb_atomic_int_fetch_and_add(AI, V)	g_atomic_int_exchange_and_add (&(AI), V)
57#define hb_atomic_int_get(AI)			g_atomic_int_get (&(AI))
58#define hb_atomic_int_set(AI, V)		g_atomic_int_set (&(AI), V)
59
60
61#elif defined(_MSC_VER)
62
63#include <intrin.h>
64
65typedef long hb_atomic_int_t;
66#define hb_atomic_int_fetch_and_add(AI, V)	_InterlockedExchangeAdd (&(AI), V)
67#define hb_atomic_int_get(AI)			(_ReadBarrier (), (AI))
68#define hb_atomic_int_set(AI, V)		((void) _InterlockedExchange (&(AI), (V)))
69
70
71#else
72
73#warning "Could not find any system to define atomic_int macros, library will NOT be thread-safe"
74
75typedef volatile int hb_atomic_int_t;
76#define hb_atomic_int_fetch_and_add(AI, V)	((AI) += (V), (AI) - (V))
77#define hb_atomic_int_get(AI)			(AI)
78#define hb_atomic_int_set(AI, V)		((void) ((AI) = (V)))
79
80
81#endif
82
83
84
85
86/* reference_count */
87
88typedef struct {
89  hb_atomic_int_t ref_count;
90
91#define HB_REFERENCE_COUNT_INVALID_VALUE ((hb_atomic_int_t) -1)
92#define HB_REFERENCE_COUNT_INVALID {HB_REFERENCE_COUNT_INVALID_VALUE}
93
94  inline void init (int v) { ref_count = v; /* non-atomic is fine */ }
95  inline int inc (void) { return hb_atomic_int_fetch_and_add (ref_count,  1); }
96  inline int dec (void) { return hb_atomic_int_fetch_and_add (ref_count, -1); }
97  inline void set (int v) { hb_atomic_int_set (ref_count, v); }
98
99  inline int get (void) const { return hb_atomic_int_get (ref_count); }
100  inline bool is_invalid (void) const { return get () == HB_REFERENCE_COUNT_INVALID_VALUE; }
101
102} hb_reference_count_t;
103
104
105/* user_data */
106
107/* XXX make this thread-safe, somehow! */
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_set_t<hb_user_data_item_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  void finish (void) { items.finish (); }
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    user_data.finish ();
174
175    return true;
176  }
177
178  inline bool set_user_data (hb_user_data_key_t *key,
179			     void *              data,
180			     hb_destroy_func_t   destroy) {
181    if (unlikely (!this || this->is_inert ()))
182      return false;
183
184    return user_data.set (key, data, destroy);
185  }
186
187  inline void *get_user_data (hb_user_data_key_t *key) {
188    return user_data.get (key);
189  }
190
191  inline void trace (const char *function) const {
192    (void) (HB_DEBUG_OBJECT &&
193	    fprintf (stderr, "OBJECT(%p) refcount=%d %s\n",
194		     this,
195		     this ? ref_count.get () : 0,
196		     function));
197  }
198
199};
200
201
202HB_END_DECLS
203
204
205/* object */
206
207template <typename Type>
208static inline void hb_object_trace (const Type *obj, const char *function)
209{
210  obj->header.trace (function);
211}
212template <typename Type>
213static inline Type *hb_object_create (void)
214{
215  Type *obj = (Type *) hb_object_header_t::create (sizeof (Type));
216  hb_object_trace (obj, HB_FUNC);
217  return obj;
218}
219template <typename Type>
220static inline bool hb_object_is_inert (const Type *obj)
221{
222  return unlikely (obj->header.is_inert ());
223}
224template <typename Type>
225static inline Type *hb_object_reference (Type *obj)
226{
227  hb_object_trace (obj, HB_FUNC);
228  obj->header.reference ();
229  return obj;
230}
231template <typename Type>
232static inline bool hb_object_destroy (Type *obj)
233{
234  hb_object_trace (obj, HB_FUNC);
235  return obj->header.destroy ();
236}
237template <typename Type>
238static inline bool hb_object_set_user_data (Type               *obj,
239					    hb_user_data_key_t *key,
240					    void *              data,
241					    hb_destroy_func_t   destroy)
242{
243  return obj->header.set_user_data (key, data, destroy);
244}
245
246template <typename Type>
247static inline void *hb_object_get_user_data (Type               *obj,
248					     hb_user_data_key_t *key)
249{
250  return obj->header.get_user_data (key);
251}
252
253
254HB_BEGIN_DECLS
255
256
257HB_END_DECLS
258
259#endif /* HB_OBJECT_PRIVATE_HH */
260