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 45 template <typename item_t, typename lock_t> 46 struct hb_lockable_set_t 47 { 48 hb_vector_t<item_t> items; 49 50 void init () { items.init (); } 51 52 template <typename T> 53 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 void remove (T v, lock_t &l) 77 { 78 l.lock (); 79 item_t *item = items.find (v); 80 if (item) 81 { 82 item_t old = *item; 83 *item = items[items.length - 1]; 84 items.pop (); 85 l.unlock (); 86 old.fini (); 87 } else { 88 l.unlock (); 89 } 90 } 91 92 template <typename T> 93 bool find (T v, item_t *i, lock_t &l) 94 { 95 l.lock (); 96 item_t *item = items.find (v); 97 if (item) 98 *i = *item; 99 l.unlock (); 100 return !!item; 101 } 102 103 template <typename T> 104 item_t *find_or_insert (T v, lock_t &l) 105 { 106 l.lock (); 107 item_t *item = items.find (v); 108 if (!item) { 109 item = items.push (v); 110 } 111 l.unlock (); 112 return item; 113 } 114 115 void fini (lock_t &l) 116 { 117 if (!items.length) 118 { 119 /* No need to lock. */ 120 items.fini (); 121 return; 122 } 123 l.lock (); 124 while (items.length) 125 { 126 item_t old = items[items.length - 1]; 127 items.pop (); 128 l.unlock (); 129 old.fini (); 130 l.lock (); 131 } 132 items.fini (); 133 l.unlock (); 134 } 135 136 }; 137 138 139 /* 140 * Reference-count. 141 */ 142 143 #define HB_REFERENCE_COUNT_INERT_VALUE 0 144 #define HB_REFERENCE_COUNT_POISON_VALUE -0x0000DEAD 145 #define HB_REFERENCE_COUNT_INIT {HB_ATOMIC_INT_INIT (HB_REFERENCE_COUNT_INERT_VALUE)} 146 147 struct hb_reference_count_t 148 { 149 mutable hb_atomic_int_t ref_count; 150 151 void init (int v = 1) { ref_count.set_relaxed (v); } 152 int get_relaxed () const { return ref_count.get_relaxed (); } 153 int inc () const { return ref_count.inc (); } 154 int dec () const { return ref_count.dec (); } 155 void fini () { ref_count.set_relaxed (HB_REFERENCE_COUNT_POISON_VALUE); } 156 157 bool is_inert () const { return ref_count.get_relaxed () == HB_REFERENCE_COUNT_INERT_VALUE; } 158 bool is_valid () const { return ref_count.get_relaxed () > 0; } 159 }; 160 161 162 /* user_data */ 163 164 struct hb_user_data_array_t 165 { 166 struct hb_user_data_item_t { 167 hb_user_data_key_t *key; 168 void *data; 169 hb_destroy_func_t destroy; 170 171 bool operator == (hb_user_data_key_t *other_key) const { return key == other_key; } 172 bool operator == (hb_user_data_item_t &other) const { return key == other.key; } 173 174 void fini () { if (destroy) destroy (data); } 175 }; 176 177 hb_mutex_t lock; 178 hb_lockable_set_t<hb_user_data_item_t, hb_mutex_t> items; 179 180 void init () { lock.init (); items.init (); } 181 182 HB_INTERNAL bool set (hb_user_data_key_t *key, 183 void * data, 184 hb_destroy_func_t destroy, 185 hb_bool_t replace); 186 187 HB_INTERNAL void *get (hb_user_data_key_t *key); 188 189 void fini () { items.fini (lock); lock.fini (); } 190 }; 191 192 193 /* 194 * Object header 195 */ 196 197 struct hb_object_header_t 198 { 199 hb_reference_count_t ref_count; 200 mutable hb_atomic_int_t writable; 201 hb_atomic_ptr_t<hb_user_data_array_t> user_data; 202 }; 203 #define HB_OBJECT_HEADER_STATIC \ 204 { \ 205 HB_REFERENCE_COUNT_INIT, \ 206 HB_ATOMIC_INT_INIT (false), \ 207 HB_ATOMIC_PTR_INIT (nullptr) \ 208 } 209 210 211 /* 212 * Object 213 */ 214 215 template <typename Type> 216 static inline void hb_object_trace (const Type *obj, const char *function) 217 { 218 DEBUG_MSG (OBJECT, (void *) obj, 219 "%s refcount=%d", 220 function, 221 obj ? obj->header.ref_count.get_relaxed () : 0); 222 } 223 224 template <typename Type> 225 static inline Type *hb_object_create () 226 { 227 Type *obj = (Type *) calloc (1, sizeof (Type)); 228 229 if (unlikely (!obj)) 230 return obj; 231 232 hb_object_init (obj); 233 hb_object_trace (obj, HB_FUNC); 234 return obj; 235 } 236 template <typename Type> 237 static inline void hb_object_init (Type *obj) 238 { 239 obj->header.ref_count.init (); 240 obj->header.writable.set_relaxed (true); 241 obj->header.user_data.init (); 242 } 243 template <typename Type> 244 static inline bool hb_object_is_inert (const Type *obj) 245 { 246 return unlikely (obj->header.ref_count.is_inert ()); 247 } 248 template <typename Type> 249 static inline bool hb_object_is_valid (const Type *obj) 250 { 251 return likely (obj->header.ref_count.is_valid ()); 252 } 253 template <typename Type> 254 static inline bool hb_object_is_immutable (const Type *obj) 255 { 256 return !obj->header.writable.get_relaxed (); 257 } 258 template <typename Type> 259 static inline void hb_object_make_immutable (const Type *obj) 260 { 261 obj->header.writable.set_relaxed (false); 262 } 263 template <typename Type> 264 static inline Type *hb_object_reference (Type *obj) 265 { 266 hb_object_trace (obj, HB_FUNC); 267 if (unlikely (!obj || hb_object_is_inert (obj))) 268 return obj; 269 assert (hb_object_is_valid (obj)); 270 obj->header.ref_count.inc (); 271 return obj; 272 } 273 template <typename Type> 274 static inline bool hb_object_destroy (Type *obj) 275 { 276 hb_object_trace (obj, HB_FUNC); 277 if (unlikely (!obj || hb_object_is_inert (obj))) 278 return false; 279 assert (hb_object_is_valid (obj)); 280 if (obj->header.ref_count.dec () != 1) 281 return false; 282 283 hb_object_fini (obj); 284 return true; 285 } 286 template <typename Type> 287 static inline void hb_object_fini (Type *obj) 288 { 289 obj->header.ref_count.fini (); /* Do this before user_data */ 290 hb_user_data_array_t *user_data = obj->header.user_data.get (); 291 if (user_data) 292 { 293 user_data->fini (); 294 free (user_data); 295 user_data = nullptr; 296 } 297 } 298 template <typename Type> 299 static inline bool hb_object_set_user_data (Type *obj, 300 hb_user_data_key_t *key, 301 void * data, 302 hb_destroy_func_t destroy, 303 hb_bool_t replace) 304 { 305 if (unlikely (!obj || hb_object_is_inert (obj))) 306 return false; 307 assert (hb_object_is_valid (obj)); 308 309 retry: 310 hb_user_data_array_t *user_data = obj->header.user_data.get (); 311 if (unlikely (!user_data)) 312 { 313 user_data = (hb_user_data_array_t *) calloc (sizeof (hb_user_data_array_t), 1); 314 if (unlikely (!user_data)) 315 return false; 316 user_data->init (); 317 if (unlikely (!obj->header.user_data.cmpexch (nullptr, user_data))) 318 { 319 user_data->fini (); 320 free (user_data); 321 goto retry; 322 } 323 } 324 325 return user_data->set (key, data, destroy, replace); 326 } 327 328 template <typename Type> 329 static inline void *hb_object_get_user_data (Type *obj, 330 hb_user_data_key_t *key) 331 { 332 if (unlikely (!obj || hb_object_is_inert (obj))) 333 return nullptr; 334 assert (hb_object_is_valid (obj)); 335 hb_user_data_array_t *user_data = obj->header.user_data.get (); 336 if (!user_data) 337 return nullptr; 338 return user_data->get (key); 339 } 340 341 342 #endif /* HB_OBJECT_HH */