gobject/gclosure.c

   1 /* GObject - GLib Type, Object, Parameter and Signal Library
   2  * Copyright (C) 2000-2001 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 /* same as G_CLOSURE_N_NOTIFIERS() (keep in sync) */
  36 #define CLOSURE_N_NOTIFIERS(cl)         (CLOSURE_N_MFUNCS (cl) + \
  37                                          (cl)->n_fnotifiers + \
  38                                          (cl)->n_inotifiers)
  39 enum {
  40   FNOTIFY,
  41   INOTIFY,
  42   PRE_NOTIFY,
  43   POST_NOTIFY
  44 };
  45
  46
  47 /* --- functions --- */
  48 GClosure*
  49 g_closure_new_simple (guint           sizeof_closure,
  50                       gpointer        data)
  51 {
  52   GClosure *closure;
  53
  54   g_return_val_if_fail (sizeof_closure >= sizeof (GClosure), NULL);
  55
  56   closure = g_malloc (sizeof_closure);
  57   closure->ref_count = 1;
  58   closure->meta_marshal = 0;
  59   closure->n_guards = 0;
  60   closure->n_fnotifiers = 0;
  61   closure->n_inotifiers = 0;
  62   closure->in_inotify = FALSE;
  63   closure->floating = TRUE;
  64   closure->derivative_flag = 0;
  65   closure->in_marshal = FALSE;
  66   closure->is_invalid = FALSE;
  67   closure->marshal = NULL;
  68   closure->data = data;
  69   closure->notifiers = NULL;
  70   memset (G_STRUCT_MEMBER_P (closure, sizeof (*closure)), 0, sizeof_closure - sizeof (*closure));
  71
  72   return closure;
  73 }
  74
  75 static inline void
  76 closure_invoke_notifiers (GClosure *closure,
  77                           guint     notify_type)
  78 {
  79   /* notifier layout:
  80    *     meta_marshal  n_guards    n_guards     n_fnotif.  n_inotifiers
  81    * ->[[meta_marshal][pre_guards][post_guards][fnotifiers][inotifiers]]
  82    *
  83    * CLOSURE_N_MFUNCS(cl)    = meta_marshal + n_guards + n_guards;
  84    * CLOSURE_N_NOTIFIERS(cl) = CLOSURE_N_MFUNCS(cl) + n_fnotifiers + n_inotifiers
  85    *
  86    * constrains/catches:
  87    * - closure->notifiers may be reloacted during callback
  88    * - closure->n_fnotifiers and closure->n_inotifiers may change during callback
  89    * - i.e. callbacks can be removed/added during invocation
  90    * - have to prepare for callback removal during invocation (->marshal & ->data)
  91    * - have to distinguish (->marshal & ->data) for INOTIFY/FNOTIFY (->in_inotify)
  92    * + closure->n_guards is const during PRE_NOTIFY & POST_NOTIFY
  93    * + closure->meta_marshal is const for all cases
  94    * + none of the callbacks can cause recursion
  95    * + closure->n_inotifiers is const 0 during FNOTIFY
  96    */
  97   switch (notify_type)
  98     {
  99       GClosureNotifyData *ndata;
 100       guint i, offs;
 101     case FNOTIFY:
 102       while (closure->n_fnotifiers)
 103         {
 104           register guint n = --closure->n_fnotifiers;
 105
 106           ndata = closure->notifiers + CLOSURE_N_MFUNCS (closure) + n;
 107           closure->marshal = (GClosureMarshal) ndata->notify;
 108           closure->data = ndata->data;
 109           ndata->notify (ndata->data, closure);
 110         }
 111       closure->marshal = NULL;
 112       closure->data = NULL;
 113       break;
 114     case INOTIFY:
 115       closure->in_inotify = TRUE;
 116       while (closure->n_inotifiers)
 117         {
 118           register guint n = --closure->n_inotifiers;
 119
 120           ndata = closure->notifiers + CLOSURE_N_MFUNCS (closure) + closure->n_fnotifiers + n;
 121           closure->marshal = (GClosureMarshal) ndata->notify;
 122           closure->data = ndata->data;
 123           ndata->notify (ndata->data, closure);
 124         }
 125       closure->marshal = NULL;
 126       closure->data = NULL;
 127       closure->in_inotify = FALSE;
 128       break;
 129     case PRE_NOTIFY:
 130       i = closure->n_guards;
 131       offs = closure->meta_marshal;
 132       while (i--)
 133         {
 134           ndata = closure->notifiers + offs + i;
 135           ndata->notify (ndata->data, closure);
 136         }
 137       break;
 138     case POST_NOTIFY:
 139       i = closure->n_guards;
 140       offs = closure->meta_marshal + i;
 141       while (i--)
 142         {
 143           ndata = closure->notifiers + offs + i;
 144           ndata->notify (ndata->data, closure);
 145         }
 146       break;
 147     }
 148 }
 149
 150 void
 151 g_closure_set_meta_marshal (GClosure       *closure,
 152                             gpointer        marshal_data,
 153                             GClosureMarshal meta_marshal)
 154 {
 155   GClosureNotifyData *notifiers;
 156   guint n;
 157
 158   g_return_if_fail (closure != NULL);
 159   g_return_if_fail (meta_marshal != NULL);
 160   g_return_if_fail (closure->is_invalid == FALSE);
 161   g_return_if_fail (closure->in_marshal == FALSE);
 162   g_return_if_fail (closure->meta_marshal == 0);
 163
 164   n = CLOSURE_N_NOTIFIERS (closure);
 165   notifiers = closure->notifiers;
 166   closure->notifiers = g_renew (GClosureNotifyData, NULL, CLOSURE_N_NOTIFIERS (closure) + 1);
 167   if (notifiers)
 168     {
 169       /* usually the meta marshal will be setup right after creation, so the
 170        * g_memmove() should be rare-case scenario
 171        */
 172       g_memmove (closure->notifiers + 1, notifiers, CLOSURE_N_NOTIFIERS (closure) * sizeof (notifiers[0]));
 173       g_free (notifiers);
 174     }
 175   closure->notifiers[0].data = marshal_data;
 176   closure->notifiers[0].notify = (GClosureNotify) meta_marshal;
 177   closure->meta_marshal = 1;
 178 }
 179
 180 void
 181 g_closure_add_marshal_guards (GClosure      *closure,
 182                               gpointer       pre_marshal_data,
 183                               GClosureNotify pre_marshal_notify,
 184                               gpointer       post_marshal_data,
 185                               GClosureNotify post_marshal_notify)
 186 {
 187   guint i;
 188
 189   g_return_if_fail (closure != NULL);
 190   g_return_if_fail (pre_marshal_notify != NULL);
 191   g_return_if_fail (post_marshal_notify != NULL);
 192   g_return_if_fail (closure->is_invalid == FALSE);
 193   g_return_if_fail (closure->in_marshal == FALSE);
 194   g_return_if_fail (closure->n_guards < CLOSURE_MAX_N_GUARDS);
 195
 196   closure->notifiers = g_renew (GClosureNotifyData, closure->notifiers, CLOSURE_N_NOTIFIERS (closure) + 2);
 197   if (closure->n_inotifiers)
 198     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 199                         closure->n_fnotifiers +
 200                         closure->n_inotifiers + 1)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 201                                                                           closure->n_fnotifiers + 0)];
 202   if (closure->n_inotifiers > 1)
 203     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 204                         closure->n_fnotifiers +
 205                         closure->n_inotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 206                                                                       closure->n_fnotifiers + 1)];
 207   if (closure->n_fnotifiers)
 208     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 209                         closure->n_fnotifiers + 1)] = closure->notifiers[CLOSURE_N_MFUNCS (closure) + 0];
 210   if (closure->n_fnotifiers > 1)
 211     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 212                         closure->n_fnotifiers)] = closure->notifiers[CLOSURE_N_MFUNCS (closure) + 1];
 213   if (closure->n_guards)
 214     closure->notifiers[(closure->meta_marshal +
 215                         closure->n_guards +
 216                         closure->n_guards + 1)] = closure->notifiers[closure->meta_marshal + closure->n_guards];
 217   i = closure->n_guards++;
 218   closure->notifiers[closure->meta_marshal + i].data = pre_marshal_data;
 219   closure->notifiers[closure->meta_marshal + i].notify = pre_marshal_notify;
 220   closure->notifiers[closure->meta_marshal + i + 1].data = post_marshal_data;
 221   closure->notifiers[closure->meta_marshal + i + 1].notify = post_marshal_notify;
 222 }
 223
 224 void
 225 g_closure_add_finalize_notifier (GClosure      *closure,
 226                                  gpointer       notify_data,
 227                                  GClosureNotify notify_func)
 228 {
 229   guint i;
 230
 231   g_return_if_fail (closure != NULL);
 232   g_return_if_fail (notify_func != NULL);
 233   g_return_if_fail (closure->n_fnotifiers < CLOSURE_MAX_N_FNOTIFIERS);
 234
 235   closure->notifiers = g_renew (GClosureNotifyData, closure->notifiers, CLOSURE_N_NOTIFIERS (closure) + 1);
 236   if (closure->n_inotifiers)
 237     closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 238                         closure->n_fnotifiers +
 239                         closure->n_inotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 240                                                                       closure->n_fnotifiers + 0)];
 241   i = CLOSURE_N_MFUNCS (closure) + closure->n_fnotifiers++;
 242   closure->notifiers[i].data = notify_data;
 243   closure->notifiers[i].notify = notify_func;
 244 }
 245
 246 void
 247 g_closure_add_invalidate_notifier (GClosure      *closure,
 248                                    gpointer       notify_data,
 249                                    GClosureNotify notify_func)
 250 {
 251   guint i;
 252
 253   g_return_if_fail (closure != NULL);
 254   g_return_if_fail (notify_func != NULL);
 255   g_return_if_fail (closure->is_invalid == FALSE);
 256   g_return_if_fail (closure->n_inotifiers < CLOSURE_MAX_N_INOTIFIERS);
 257
 258   closure->notifiers = g_renew (GClosureNotifyData, closure->notifiers, CLOSURE_N_NOTIFIERS (closure) + 1);
 259   i = CLOSURE_N_MFUNCS (closure) + closure->n_fnotifiers + closure->n_inotifiers++;
 260   closure->notifiers[i].data = notify_data;
 261   closure->notifiers[i].notify = notify_func;
 262 }
 263
 264 static inline gboolean
 265 closure_try_remove_inotify (GClosure       *closure,
 266                             gpointer       notify_data,
 267                             GClosureNotify notify_func)
 268 {
 269   GClosureNotifyData *ndata, *nlast;
 270
 271   nlast = closure->notifiers + CLOSURE_N_NOTIFIERS (closure) - 1;
 272   for (ndata = nlast + 1 - closure->n_inotifiers; ndata <= nlast; ndata++)
 273     if (ndata->notify == notify_func && ndata->data == notify_data)
 274       {
 275         closure->n_inotifiers -= 1;
 276         if (ndata < nlast)
 277           *ndata = *nlast;
 278
 279         return TRUE;
 280       }
 281   return FALSE;
 282 }
 283
 284 static inline gboolean
 285 closure_try_remove_fnotify (GClosure       *closure,
 286                             gpointer       notify_data,
 287                             GClosureNotify notify_func)
 288 {
 289   GClosureNotifyData *ndata, *nlast;
 290
 291   nlast = closure->notifiers + CLOSURE_N_NOTIFIERS (closure) - closure->n_inotifiers - 1;
 292   for (ndata = nlast + 1 - closure->n_fnotifiers; ndata <= nlast; ndata++)
 293     if (ndata->notify == notify_func && ndata->data == notify_data)
 294       {
 295         closure->n_fnotifiers -= 1;
 296         if (ndata < nlast)
 297           *ndata = *nlast;
 298         if (closure->n_inotifiers)
 299           closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 300                               closure->n_fnotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
 301                                                                             closure->n_fnotifiers +
 302                                                                             closure->n_inotifiers)];
 303         return TRUE;
 304       }
 305   return FALSE;
 306 }
 307
 308 GClosure*
 309 g_closure_ref (GClosure *closure)
 310 {
 311   g_return_val_if_fail (closure != NULL, NULL);
 312   g_return_val_if_fail (closure->ref_count > 0, NULL);
 313   g_return_val_if_fail (closure->ref_count < CLOSURE_MAX_REF_COUNT, NULL);
 314
 315   closure->ref_count += 1;
 316
 317   return closure;
 318 }
 319
 320 void
 321 g_closure_invalidate (GClosure *closure)
 322 {
 323   g_return_if_fail (closure != NULL);
 324
 325   if (!closure->is_invalid)
 326     {
 327       closure->ref_count += 1;  /* preserve floating flag */
 328       closure->is_invalid = TRUE;
 329       closure_invoke_notifiers (closure, INOTIFY);
 330       g_closure_unref (closure);
 331     }
 332 }
 333
 334 void
 335 g_closure_unref (GClosure *closure)
 336 {
 337   g_return_if_fail (closure != NULL);
 338   g_return_if_fail (closure->ref_count > 0);
 339
 340   if (closure->ref_count == 1)  /* last unref, invalidate first */
 341     g_closure_invalidate (closure);
 342
 343   closure->ref_count -= 1;
 344
 345   if (closure->ref_count == 0)
 346     {
 347       closure_invoke_notifiers (closure, FNOTIFY);
 348       g_free (closure->notifiers);
 349       g_free (closure);
 350     }
 351 }
 352
 353 void
 354 g_closure_sink (GClosure *closure)
 355 {
 356   g_return_if_fail (closure != NULL);
 357   g_return_if_fail (closure->ref_count > 0);
 358
 359   /* floating is basically a kludge to avoid creating closures
 360    * with a ref_count of 0. so the intial ref_count a closure has
 361    * is unowned. with invoking g_closure_sink() code may
 362    * indicate that it takes over that intiial ref_count.
 363    */
 364   if (closure->floating)
 365     {
 366       closure->floating = FALSE;
 367       if (closure->ref_count > 1)
 368         closure->ref_count -= 1;
 369       else
 370         g_closure_unref (closure);
 371     }
 372 }
 373
 374 void
 375 g_closure_remove_invalidate_notifier (GClosure      *closure,
 376                                       gpointer       notify_data,
 377                                       GClosureNotify notify_func)
 378 {
 379   g_return_if_fail (closure != NULL);
 380   g_return_if_fail (notify_func != NULL);
 381
 382   if (closure->is_invalid && closure->in_inotify && /* account removal of notify_func() while its called */
 383       ((gpointer) closure->marshal) == ((gpointer) notify_func) && closure->data == notify_data)
 384     closure->marshal = NULL;
 385   else if (!closure_try_remove_inotify (closure, notify_data, notify_func))
 386     g_warning (G_STRLOC ": unable to remove uninstalled invalidation notifier: %p (%p)",
 387                notify_func, notify_data);
 388 }
 389
 390 void
 391 g_closure_remove_finalize_notifier (GClosure      *closure,
 392                                     gpointer       notify_data,
 393                                     GClosureNotify notify_func)
 394 {
 395   g_return_if_fail (closure != NULL);
 396   g_return_if_fail (notify_func != NULL);
 397
 398   if (closure->is_invalid && !closure->in_inotify && /* account removal of notify_func() while its called */
 399       ((gpointer) closure->marshal) == ((gpointer) notify_func) && closure->data == notify_data)
 400     closure->marshal = NULL;
 401   else if (!closure_try_remove_fnotify (closure, notify_data, notify_func))
 402     g_warning (G_STRLOC ": unable to remove uninstalled finalization notifier: %p (%p)",
 403                notify_func, notify_data);
 404 }
 405
 406 void
 407 g_closure_invoke (GClosure       *closure,
 408                   GValue /*out*/ *return_value,
 409                   guint           n_param_values,
 410                   const GValue   *param_values,
 411                   gpointer        invocation_hint)
 412 {
 413   g_return_if_fail (closure != NULL);
 414
 415   if (!closure->is_invalid)
 416     {
 417       GClosureMarshal marshal;
 418       gpointer marshal_data;
 419       gboolean in_marshal = closure->in_marshal;
 420
 421       g_return_if_fail (closure->marshal || closure->meta_marshal);
 422
 423       closure->ref_count += 1;  /* preserve floating flag */
 424       closure->in_marshal = TRUE;
 425       if (closure->meta_marshal)
 426         {
 427           marshal_data = closure->notifiers[0].data;
 428           marshal = (GClosureMarshal) closure->notifiers[0].notify;
 429         }
 430       else
 431         {
 432           marshal_data = NULL;
 433           marshal = closure->marshal;
 434         }
 435       if (!in_marshal)
 436         closure_invoke_notifiers (closure, PRE_NOTIFY);
 437       marshal (closure,
 438                return_value,
 439                n_param_values, param_values,
 440                invocation_hint,
 441                marshal_data);
 442       if (!in_marshal)
 443         closure_invoke_notifiers (closure, POST_NOTIFY);
 444       closure->in_marshal = in_marshal;
 445       g_closure_unref (closure);
 446     }
 447 }
 448
 449 void
 450 g_closure_set_marshal (GClosure       *closure,
 451                        GClosureMarshal marshal)
 452 {
 453   g_return_if_fail (closure != NULL);
 454   g_return_if_fail (marshal != NULL);
 455
 456   if (closure->marshal && closure->marshal != marshal)
 457     g_warning ("attempt to override closure->marshal (%p) with new marshal (%p)",
 458                closure->marshal, marshal);
 459   else
 460     closure->marshal = marshal;
 461 }
 462
 463 GClosure*
 464 g_cclosure_new (GCallback      callback_func,
 465                 gpointer       user_data,
 466                 GClosureNotify destroy_data)
 467 {
 468   GClosure *closure;
 469
 470   g_return_val_if_fail (callback_func != NULL, NULL);
 471
 472   closure = g_closure_new_simple (sizeof (GCClosure), user_data);
 473   if (destroy_data)
 474     g_closure_add_finalize_notifier (closure, user_data, destroy_data);
 475   ((GCClosure*) closure)->callback = (gpointer) callback_func;
 476
 477   return closure;
 478 }
 479
 480 GClosure*
 481 g_cclosure_new_swap (GCallback      callback_func,
 482                      gpointer       user_data,
 483                      GClosureNotify destroy_data)
 484 {
 485   GClosure *closure;
 486
 487   g_return_val_if_fail (callback_func != NULL, NULL);
 488
 489   closure = g_closure_new_simple (sizeof (GCClosure), user_data);
 490   if (destroy_data)
 491     g_closure_add_finalize_notifier (closure, user_data, destroy_data);
 492   ((GCClosure*) closure)->callback = (gpointer) callback_func;
 493   closure->derivative_flag = TRUE;
 494
 495   return closure;
 496 }
 497
 498 static void
 499 g_type_class_meta_marshal (GClosure       *closure,
 500                            GValue /*out*/ *return_value,
 501                            guint           n_param_values,
 502                            const GValue   *param_values,
 503                            gpointer        invocation_hint,
 504                            gpointer        marshal_data)
 505 {
 506   GTypeClass *class;
 507   gpointer callback;
 508   /* GType itype = (GType) closure->data; */
 509   guint offset = GPOINTER_TO_UINT (marshal_data);
 510
 511   class = G_TYPE_INSTANCE_GET_CLASS (g_value_peek_pointer (param_values + 0), itype, GTypeClass);
 512   callback = G_STRUCT_MEMBER (gpointer, class, offset);
 513   if (callback)
 514     closure->marshal (closure,
 515                       return_value,
 516                       n_param_values, param_values,
 517                       invocation_hint,
 518                       callback);
 519 }
 520
 521 static void
 522 g_type_iface_meta_marshal (GClosure       *closure,
 523                            GValue /*out*/ *return_value,
 524                            guint           n_param_values,
 525                            const GValue   *param_values,
 526                            gpointer        invocation_hint,
 527                            gpointer        marshal_data)
 528 {
 529   GTypeClass *class;
 530   gpointer callback;
 531   GType itype = (GType) closure->data;
 532   guint offset = GPOINTER_TO_UINT (marshal_data);
 533
 534   class = G_TYPE_INSTANCE_GET_INTERFACE (g_value_peek_pointer (param_values + 0), itype, GTypeClass);
 535   callback = G_STRUCT_MEMBER (gpointer, class, offset);
 536   if (callback)
 537     closure->marshal (closure,
 538                       return_value,
 539                       n_param_values, param_values,
 540                       invocation_hint,
 541                       callback);
 542 }
 543
 544 GClosure*
 545 g_signal_type_cclosure_new (GType    itype,
 546                             guint    struct_offset)
 547 {
 548   GClosure *closure;
 549
 550   g_return_val_if_fail (G_TYPE_IS_CLASSED (itype) || G_TYPE_IS_INTERFACE (itype), NULL);
 551   g_return_val_if_fail (struct_offset >= sizeof (GTypeClass), NULL);
 552
 553   closure = g_closure_new_simple (sizeof (GClosure), (gpointer) itype);
 554   if (G_TYPE_IS_INTERFACE (itype))
 555     g_closure_set_meta_marshal (closure, GUINT_TO_POINTER (struct_offset), g_type_iface_meta_marshal);
 556   else
 557     g_closure_set_meta_marshal (closure, GUINT_TO_POINTER (struct_offset), g_type_class_meta_marshal);
 558
 559   return closure;
 560 }