gobject/gclosure.c

   1 /* GObject - GLib Type, Object, Parameter and Signal Library
   2  * Copyright (C) 2000 Red Hat, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General
  15  * Public License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include        "gclosure.h"
  21
  22 #include        "gvalue.h"
  23 #include        <string.h>
  24
  25
  26 /* FIXME: need caching allocators
  27  */
  28
  29 #define CLOSURE_MAX_REF_COUNT           ((1 << 15) - 1)
  30 #define CLOSURE_MAX_N_GUARDS            ((1 << 1) - 1)
  31 #define CLOSURE_MAX_N_FNOTIFIERS        ((1 << 2) - 1)
  32 #define CLOSURE_MAX_N_INOTIFIERS        ((1 << 8) - 1)
  33 #define CLOSURE_N_MFUNCS(cl)            ((cl)->meta_marshal + \
  34                                          ((cl)->n_guards << 1L))
  35 #define CLOSURE_N_NOTIFIERS(cl)         (CLOSURE_N_MFUNCS (cl) + \
  36                                          (cl)->n_fnotifiers + \
  37                                          (cl)->n_inotifiers)
  38 enum {
  39   FNOTIFY,
  40   INOTIFY,
  41   PRE_NOTIFY,
  42   POST_NOTIFY
  43 };
  44
  45
  46 /* --- functions --- */
  47 GClosure*
  48 g_closure_new_simple (guint           sizeof_closure,
  49                       gpointer        data)
  50 {
  51   GClosure *closure;
  52
  53   g_return_val_if_fail (sizeof_closure >= sizeof (GClosure), NULL);
  54
  55   closure = g_malloc (sizeof_closure);
  56   closure->ref_count = 1;
  57   closure->meta_marshal = 0;
  58   closure->n_guards = 0;
  59   closure->n_fnotifiers = 0;
  60   closure->n_inotifiers = 0;
  61   closure->in_inotify = FALSE;
  62   closure->floating = TRUE;
  63   closure->derivative_flag = 0;
  64   closure->in_marshal = FALSE;
  65   closure->is_invalid = FALSE;
  66   closure->marshal = NULL;
  67   closure->data = data;
  68   closure->notifiers = NULL;
  69   memset (G_STRUCT_MEMBER_P (closure, sizeof (*closure)), 0, sizeof_closure - sizeof (*closure));
  70
  71   return closure;
  72 }
  73
  74 static inline void
  75 closure_invoke_notifiers (GClosure *closure,
  76                           guint     notify_type)
  77 {
  78   /* notifier layout:
  79    *     meta_marshal  n_guards    n_guards     n_fnotif.  n_inotifiers
  80    * ->[[meta_marshal][pre_guards][post_guards][fnotifers][inotifiers]]
  81    *
  82    * CLOSURE_N_MFUNCS(cl)    = meta_marshal + n_guards + n_guards;
  83    * CLOSURE_N_NOTIFIERS(cl) = CLOSURE_N_MFUNCS(cl) + n_fnotifiers + n_inotifiers
  84    *
  85    * constrains/catches:
  86    * - closure->notifiers may be reloacted during callback
  87    * - closure->n_fnotifiers and closure->n_inotifiers may change during callback
  88    * - i.e. callbacks can be removed/added during invocation
  89    * - have to prepare for callback removal during invocation (->marshal & ->data)
  90    * - have to distinguish (->marshal & ->data) for INOTIFY/FNOTIFY (->in_inotify)
  91    * + closure->n_guards is const during PRE_NOTIFY & POST_NOTIFY
  92    * + closure->meta_marshal is const for all cases
  93    * + none of the callbacks can cause recursion
  94    * + closure->n_inotifiers is const 0 during FNOTIFY
  95    */
  96   switch (notify_type)
  97     {
  98       GClosureNotifyData *ndata;
  99       guint i, offs;
 100     case FNOTIFY:
 101       while (closure->n_fnotifiers)
 102         {
 103           register guint n = --closure->n_fnotifiers;
 104
 105           ndata = closure->notifiers + CLOSURE_N_MFUNCS (closure) + n;
 106           closure->marshal = (gpointer) ndata->notify;
 107           closure->data = ndata->data;
 108           ndata->notify (ndata->data, closure);
 109         }
 110       closure->marshal = NULL;
 111       closure->data = NULL;
 112       break;
 113     case INOTIFY:
 114       closure->in_inotify = TRUE;
 115       while (closure->n_inotifiers)
 116         {
 117           register guint n = --closure->n_inotifiers;
 118
 119           ndata = closure->notifiers + CLOSURE_N_MFUNCS (closure) + closure->n_fnotifiers + n;
 120           closure->marshal = (gpointer) ndata->notify;
 121           closure->data = ndata->data;
 122           ndata->notify (ndata->data, closure);
 123         }
 124       closure->marshal = NULL;
 125       closure->data = NULL;
 126       closure->in_inotify = FALSE;
 127       break;
 128     case PRE_NOTIFY:
 129       i = closure->n_guards;
 130       offs = closure->meta_marshal;
 131       while (i--)
 132         {
 133           ndata = closure->notifiers + offs + i;
 134           ndata->notify (ndata->data, closure);
 135         }
 136       break;
 137     case POST_NOTIFY:
 138       i = closure->n_guards;
 139       offs = closure->meta_marshal + i;
 140       while (i--)
 141         {
 142           ndata = closure->notifiers + offs + i;
 143           ndata->notify (ndata->data, closure);
 144         }
 145       break;
 146     }
 147 }
 148
 149 void
 150 g_closure_set_meta_marshal (GClosure       *closure,
 151                             gpointer        marshal_data,
 152                             GClosureMarshal meta_marshal)
 153 {
 154   GClosureNotifyData *notifiers;
 155   guint n;
 156
 157   g_return_if_fail (closure != NULL);
 158   g_return_if_fail (meta_marshal != NULL);
 159   g_return_if_fail (closure->is_invalid == FALSE);
 160   g_return_if_fail (closure->in_marshal == FALSE);
 161   g_return_if_fail (closure->meta_marshal == FALSE);
 162
 163   n = CLOSURE_N_NOTIFIERS (closure);
 164   notifiers = closure->notifiers;
 165   closure->notifiers = g_renew (GClosureNotifyData, NULL, CLOSURE_N_NOTIFIERS (closure) + 1);
 166   if (notifiers)
 167     {
 168       /* usually the meta marshal will be setup right after creation, so the
 169        * g_memmove() should be rare-case scenario
 170        */
 171       g_memmove (closure->notifiers + 1, notifiers, CLOSURE_N_NOTIFIERS (closure) * sizeof (notifiers[0]));
 172       g_free (notifiers);
 173     }
 174   closure->notifiers[0].data = marshal_data;
 175   closure->notifiers[0].notify = (GClosureNotify) meta_marshal;
 176   closure->meta_marshal = 1;
 177 }
 178
 179 void
 180 g_closure_add_marshal_guards (GClosure      *closure,
 181                               gpointer       pre_marshal_data,
 182                               GClosureNotify pre_marshal_notify,
 183                               gpointer       post_marshal_data,
 184                               GClosureNotify post_marshal_notify)
 185 {
 186   guint i;
 187
 188   g_return_if_fail (closure != NULL);
 189   g_return_if_fail (pre_marshal_notify != NULL);
 190   g_return_if_fail (post_marshal_notify != NULL);
 191   g_return_if_fail (closure->is_invalid == FALSE);
 192   g_return_if_fail (closure->in_marshal == FALSE);
 193   g_return_if_fail (closure->n_guards < CLOSURE_MAX_N_GUARDS);
 194
 195   closure->notifiers = g_renew (GClosureNotifyData, closure->notifiers, CLOSURE_N_NOTIFIERS (closure) + 2);
 196   if (closure->n_inotifiers)
 197     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 198                         closure->n_fnotifiers +
 199                         closure->n_inotifiers + 1)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 200                                                                           closure->n_fnotifiers + 0)];
 201   if (closure->n_inotifiers > 1)
 202     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 203                         closure->n_fnotifiers +
 204                         closure->n_inotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 205                                                                       closure->n_fnotifiers + 1)];
 206   if (closure->n_fnotifiers)
 207     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 208                         closure->n_fnotifiers + 1)] = closure->notifiers[CLOSURE_N_MFUNCS (closure) + 0];
 209   if (closure->n_fnotifiers > 1)
 210     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 211                         closure->n_fnotifiers)] = closure->notifiers[CLOSURE_N_MFUNCS (closure) + 1];
 212   if (closure->n_guards)
 213     closure->notifiers[(closure->meta_marshal +
 214                         closure->n_guards +
 215                         closure->n_guards + 1)] = closure->notifiers[closure->meta_marshal + closure->n_guards];
 216   i = closure->n_guards++;
 217   closure->notifiers[closure->meta_marshal + i].data = pre_marshal_data;
 218   closure->notifiers[closure->meta_marshal + i].notify = pre_marshal_notify;
 219   closure->notifiers[closure->meta_marshal + i + 1].data = post_marshal_data;
 220   closure->notifiers[closure->meta_marshal + i + 1].notify = post_marshal_notify;
 221 }
 222
 223 void
 224 g_closure_add_fnotify (GClosure      *closure,
 225                        gpointer       notify_data,
 226                        GClosureNotify notify_func)
 227 {
 228   guint i;
 229
 230   g_return_if_fail (closure != NULL);
 231   g_return_if_fail (notify_func != NULL);
 232   g_return_if_fail (closure->n_fnotifiers < CLOSURE_MAX_N_FNOTIFIERS);
 233
 234   closure->notifiers = g_renew (GClosureNotifyData, closure->notifiers, CLOSURE_N_NOTIFIERS (closure) + 1);
 235   if (closure->n_inotifiers)
 236     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 237                         closure->n_fnotifiers +
 238                         closure->n_inotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 239                                                                       closure->n_fnotifiers + 0)];
 240   i = CLOSURE_N_MFUNCS (closure) + closure->n_fnotifiers++;
 241   closure->notifiers[i].data = notify_data;
 242   closure->notifiers[i].notify = notify_func;
 243 }
 244
 245 void
 246 g_closure_add_inotify (GClosure      *closure,
 247                        gpointer       notify_data,
 248                        GClosureNotify notify_func)
 249 {
 250   guint i;
 251
 252   g_return_if_fail (closure != NULL);
 253   g_return_if_fail (notify_func != NULL);
 254   g_return_if_fail (closure->is_invalid == FALSE);
 255   g_return_if_fail (closure->n_inotifiers < CLOSURE_MAX_N_INOTIFIERS);
 256
 257   closure->notifiers = g_renew (GClosureNotifyData, closure->notifiers, CLOSURE_N_NOTIFIERS (closure) + 1);
 258   i = CLOSURE_N_MFUNCS (closure) + closure->n_fnotifiers + closure->n_inotifiers++;
 259   closure->notifiers[i].data = notify_data;
 260   closure->notifiers[i].notify = notify_func;
 261 }
 262
 263 static inline gboolean
 264 closure_try_remove_inotify (GClosure       *closure,
 265                             gpointer       notify_data,
 266                             GClosureNotify notify_func)
 267 {
 268   GClosureNotifyData *ndata, *nlast;
 269
 270   nlast = closure->notifiers + CLOSURE_N_NOTIFIERS (closure) - 1;
 271   for (ndata = nlast + 1 - closure->n_inotifiers; ndata <= nlast; ndata++)
 272     if (ndata->notify == notify_func && ndata->data == notify_data)
 273       {
 274         closure->n_inotifiers -= 1;
 275         if (ndata < nlast)
 276           *ndata = *nlast;
 277
 278         return TRUE;
 279       }
 280   return FALSE;
 281 }
 282
 283 static inline gboolean
 284 closure_try_remove_fnotify (GClosure       *closure,
 285                             gpointer       notify_data,
 286                             GClosureNotify notify_func)
 287 {
 288   GClosureNotifyData *ndata, *nlast;
 289
 290   nlast = closure->notifiers + CLOSURE_N_NOTIFIERS (closure) - closure->n_inotifiers - 1;
 291   for (ndata = nlast + 1 - closure->n_fnotifiers; ndata <= nlast; ndata++)
 292     if (ndata->notify == notify_func && ndata->data == notify_data)
 293       {
 294         closure->n_fnotifiers -= 1;
 295         if (ndata < nlast)
 296           *ndata = *nlast;
 297         if (closure->n_inotifiers)
 298           closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 299                               closure->n_fnotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 300                                                                             closure->n_fnotifiers +
 301                                                                             closure->n_inotifiers)];
 302         return TRUE;
 303       }
 304   return FALSE;
 305 }
 306
 307 GClosure*
 308 g_closure_ref (GClosure *closure)
 309 {
 310   g_return_val_if_fail (closure != NULL, NULL);
 311   g_return_val_if_fail (closure->ref_count > 0, NULL);
 312   g_return_val_if_fail (closure->ref_count < CLOSURE_MAX_REF_COUNT, NULL);
 313
 314   /* floating is basically a kludge to avoid creating closures
 315    * with a ref_count of 0. so the first one doing _ref() will
 316    * own the closure's initial ref_count
 317    */
 318   if (closure->floating)
 319     closure->floating = FALSE;
 320   else
 321     closure->ref_count += 1;
 322
 323   return closure;
 324 }
 325
 326 void
 327 g_closure_invalidate (GClosure *closure)
 328 {
 329   g_return_if_fail (closure != NULL);
 330
 331   if (!closure->is_invalid)
 332     {
 333       closure->ref_count += 1;  /* preserve floating flag */
 334       closure->is_invalid = TRUE;
 335       closure_invoke_notifiers (closure, INOTIFY);
 336       g_closure_unref (closure);
 337     }
 338 }
 339
 340 void
 341 g_closure_unref (GClosure *closure)
 342 {
 343   g_return_if_fail (closure != NULL);
 344   g_return_if_fail (closure->ref_count > 0);
 345
 346   if (closure->ref_count == 1)  /* last unref, invalidate first */
 347     g_closure_invalidate (closure);
 348
 349   closure->ref_count -= 1;
 350
 351   if (closure->ref_count == 0)
 352     {
 353       closure_invoke_notifiers (closure, FNOTIFY);
 354       g_free (closure->notifiers);
 355       g_free (closure);
 356     }
 357 }
 358
 359 void
 360 g_closure_remove_inotify (GClosure      *closure,
 361                           gpointer       notify_data,
 362                           GClosureNotify notify_func)
 363 {
 364   g_return_if_fail (closure != NULL);
 365   g_return_if_fail (notify_func != NULL);
 366
 367   if (closure->is_invalid && closure->in_inotify && /* account removal of notify_func() while its called */
 368       ((gpointer) closure->marshal) == ((gpointer) notify_func) && closure->data == notify_data)
 369     closure->marshal = NULL;
 370   else if (!closure_try_remove_inotify (closure, notify_data, notify_func))
 371     g_warning (G_STRLOC ": unable to remove uninstalled invalidation notifier: %p (%p)",
 372                notify_func, notify_data);
 373 }
 374
 375 void
 376 g_closure_remove_fnotify (GClosure      *closure,
 377                           gpointer       notify_data,
 378                           GClosureNotify notify_func)
 379 {
 380   g_return_if_fail (closure != NULL);
 381   g_return_if_fail (notify_func != NULL);
 382
 383   if (closure->is_invalid && !closure->in_inotify && /* account removal of notify_func() while its called */
 384       ((gpointer) closure->marshal) == ((gpointer) notify_func) && closure->data == notify_data)
 385     closure->marshal = NULL;
 386   else if (!closure_try_remove_fnotify (closure, notify_data, notify_func))
 387     g_warning (G_STRLOC ": unable to remove uninstalled finalization notifier: %p (%p)",
 388                notify_func, notify_data);
 389 }
 390
 391 void
 392 g_closure_invoke (GClosure       *closure,
 393                   GValue /*out*/ *return_value,
 394                   guint           n_param_values,
 395                   const GValue   *param_values,
 396                   gpointer        invocation_hint)
 397 {
 398   g_return_if_fail (closure != NULL);
 399   g_return_if_fail (closure->marshal || closure->meta_marshal);
 400
 401   if (!closure->is_invalid)
 402     {
 403       GClosureMarshal marshal;
 404       gpointer marshal_data;
 405       gboolean in_marshal = closure->in_marshal;
 406
 407       closure->ref_count += 1;  /* preserve floating flag */
 408       closure->in_marshal = TRUE;
 409       if (closure->meta_marshal)
 410         {
 411           marshal_data = closure->notifiers[0].data;
 412           marshal = (GClosureMarshal) closure->notifiers[0].notify;
 413         }
 414       else
 415         {
 416           marshal_data = NULL;
 417           marshal = closure->marshal;
 418         }
 419       if (!in_marshal)
 420         closure_invoke_notifiers (closure, PRE_NOTIFY);
 421       marshal (closure,
 422                return_value,
 423                n_param_values, param_values,
 424                invocation_hint,
 425                marshal_data);
 426       if (!in_marshal)
 427         closure_invoke_notifiers (closure, POST_NOTIFY);
 428       closure->in_marshal = in_marshal;
 429       g_closure_unref (closure);
 430     }
 431 }
 432
 433 void
 434 g_closure_set_marshal (GClosure       *closure,
 435                        GClosureMarshal marshal)
 436 {
 437   g_return_if_fail (closure != NULL);
 438   g_return_if_fail (marshal != NULL);
 439
 440   if (closure->marshal && closure->marshal != marshal)
 441     g_warning ("attempt to override closure->marshal (%p) with new marshal (%p)",
 442                closure->marshal, marshal);
 443   else
 444     closure->marshal = marshal;
 445 }
 446
 447 GClosure*
 448 g_cclosure_new (GCallback      callback_func,
 449                 gpointer       user_data,
 450                 GClosureNotify destroy_data)
 451 {
 452   GClosure *closure;
 453
 454   g_return_val_if_fail (callback_func != NULL, NULL);
 455
 456   closure = g_closure_new_simple (sizeof (GCClosure), user_data);
 457   if (destroy_data)
 458     g_closure_add_fnotify (closure, user_data, destroy_data);
 459   ((GCClosure*) closure)->callback = callback_func;
 460
 461   return closure;
 462 }
 463
 464 GClosure*
 465 g_cclosure_new_swap (GCallback      callback_func,
 466                      gpointer       user_data,
 467                      GClosureNotify destroy_data)
 468 {
 469   GClosure *closure;
 470
 471   g_return_val_if_fail (callback_func != NULL, NULL);
 472
 473   closure = g_closure_new_simple (sizeof (GCClosure), user_data);
 474   if (destroy_data)
 475     g_closure_add_fnotify (closure, user_data, destroy_data);
 476   ((GCClosure*) closure)->callback = callback_func;
 477   closure->derivative_flag = TRUE;
 478
 479   return closure;
 480 }
 481
 482 static void
 483 g_type_class_meta_marshal (GClosure       *closure,
 484                            GValue /*out*/ *return_value,
 485                            guint           n_param_values,
 486                            const GValue   *param_values,
 487                            gpointer        invocation_hint,
 488                            gpointer        marshal_data)
 489 {
 490   GTypeClass *class;
 491   gpointer callback;
 492   /* GType itype = GPOINTER_TO_UINT (closure->data); */
 493   guint offset = GPOINTER_TO_UINT (marshal_data);
 494
 495   class = G_TYPE_INSTANCE_GET_CLASS (g_value_get_as_pointer (param_values + 0), itype, GTypeClass);
 496   callback = G_STRUCT_MEMBER (gpointer, class, offset);
 497   if (callback)
 498     closure->marshal (closure,
 499                       return_value,
 500                       n_param_values, param_values,
 501                       invocation_hint,
 502                       callback);
 503 }
 504
 505 static void
 506 g_type_iface_meta_marshal (GClosure       *closure,
 507                            GValue /*out*/ *return_value,
 508                            guint           n_param_values,
 509                            const GValue   *param_values,
 510                            gpointer        invocation_hint,
 511                            gpointer        marshal_data)
 512 {
 513   GTypeClass *class;
 514   gpointer callback;
 515   GType itype = GPOINTER_TO_UINT (closure->data);
 516   guint offset = GPOINTER_TO_UINT (marshal_data);
 517
 518   class = G_TYPE_INSTANCE_GET_INTERFACE (g_value_get_as_pointer (param_values + 0), itype, GTypeClass);
 519   callback = G_STRUCT_MEMBER (gpointer, class, offset);
 520   if (callback)
 521     closure->marshal (closure,
 522                       return_value,
 523                       n_param_values, param_values,
 524                       invocation_hint,
 525                       callback);
 526 }
 527
 528 GClosure*
 529 g_signal_type_cclosure_new (GType    itype,
 530                             guint    struct_offset)
 531 {
 532   GClosure *closure;
 533
 534   g_return_val_if_fail (G_TYPE_IS_CLASSED (itype) || G_TYPE_IS_INTERFACE (itype), NULL);
 535   g_return_val_if_fail (struct_offset >= sizeof (GTypeClass), NULL);
 536
 537   closure = g_closure_new_simple (sizeof (GClosure), GUINT_TO_POINTER (itype));
 538   if (G_TYPE_IS_INTERFACE (itype))
 539     g_closure_set_meta_marshal (closure, GUINT_TO_POINTER (struct_offset), g_type_iface_meta_marshal);
 540   else
 541     g_closure_set_meta_marshal (closure, GUINT_TO_POINTER (struct_offset), g_type_class_meta_marshal);
 542
 543   return closure;
 544 }