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 #include        "gclosure.h"
  20
  21 #include        "gvalue.h"
  22 #include        "gobjectalias.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
  40 /* union of first int we need to make atomic */
  41 typedef union {
  42   GClosure bits;
  43   gint atomic;
  44 } GAtomicClosureBits;
  45
  46 #define BITS_AS_INT(b)  (((GAtomicClosureBits*)(b))->atomic)
  47
  48 #define CLOSURE_READ_BITS(cl,bits)      (BITS_AS_INT(bits) = g_atomic_int_get ((gint*)(cl)))
  49 #define CLOSURE_READ_BITS2(cl,old,new)  (BITS_AS_INT(old) = CLOSURE_READ_BITS (cl, new))
  50 #define CLOSURE_SWAP_BITS(cl,old,new)   (g_atomic_int_compare_and_exchange ((gint*)(cl),        \
  51                                                 BITS_AS_INT(old),BITS_AS_INT(new)))
  52
  53 #define CLOSURE_REF(closure)                                                    \
  54 G_STMT_START {                                                                  \
  55   GClosure old, new;                                                            \
  56   do {                                                                          \
  57     CLOSURE_READ_BITS2 (closure, &old, &new);                                   \
  58     new.ref_count++;                                                            \
  59   }                                                                             \
  60   while (!CLOSURE_SWAP_BITS (closure, &old, &new));                             \
  61 } G_STMT_END
  62
  63
  64 #define CLOSURE_UNREF(closure, is_zero)                                         \
  65 G_STMT_START {                                                                  \
  66   GClosure old, new;                                                            \
  67   do {                                                                          \
  68     CLOSURE_READ_BITS2 (closure, &old, &new);                                   \
  69     if (old.ref_count == 1)     /* last unref, invalidate first */              \
  70       g_closure_invalidate ((closure));                                         \
  71     new.ref_count--;                                                            \
  72     is_zero = (new.ref_count == 0);                                             \
  73   }                                                                             \
  74   while (!CLOSURE_SWAP_BITS (closure, &old, &new));                             \
  75 } G_STMT_END
  76
  77 enum {
  78   FNOTIFY,
  79   INOTIFY,
  80   PRE_NOTIFY,
  81   POST_NOTIFY
  82 };
  83
  84
  85 /* --- functions --- */
  86 GClosure*
  87 g_closure_new_simple (guint           sizeof_closure,
  88                       gpointer        data)
  89 {
  90   GClosure *closure;
  91
  92   g_return_val_if_fail (sizeof_closure >= sizeof (GClosure), NULL);
  93
  94   closure = g_malloc (sizeof_closure);
  95   closure->ref_count = 1;
  96   closure->meta_marshal = 0;
  97   closure->n_guards = 0;
  98   closure->n_fnotifiers = 0;
  99   closure->n_inotifiers = 0;
 100   closure->in_inotify = FALSE;
 101   closure->floating = TRUE;
 102   closure->derivative_flag = 0;
 103   closure->in_marshal = FALSE;
 104   closure->is_invalid = FALSE;
 105   closure->marshal = NULL;
 106   closure->data = data;
 107   closure->notifiers = NULL;
 108   memset (G_STRUCT_MEMBER_P (closure, sizeof (*closure)), 0, sizeof_closure - sizeof (*closure));
 109
 110   return closure;
 111 }
 112
 113 static inline void
 114 closure_invoke_notifiers (GClosure *closure,
 115                           guint     notify_type)
 116 {
 117   GClosure bits, new;
 118
 119   /* notifier layout:
 120    *     meta_marshal  n_guards    n_guards     n_fnotif.  n_inotifiers
 121    * ->[[meta_marshal][pre_guards][post_guards][fnotifiers][inotifiers]]
 122    *
 123    * CLOSURE_N_MFUNCS(cl)    = meta_marshal + n_guards + n_guards;
 124    * CLOSURE_N_NOTIFIERS(cl) = CLOSURE_N_MFUNCS(cl) + n_fnotifiers + n_inotifiers
 125    *
 126    * constrains/catches:
 127    * - closure->notifiers may be reloacted during callback
 128    * - closure->n_fnotifiers and closure->n_inotifiers may change during callback
 129    * - i.e. callbacks can be removed/added during invocation
 130    * - have to prepare for callback removal during invocation (->marshal & ->data)
 131    * - have to distinguish (->marshal & ->data) for INOTIFY/FNOTIFY (->in_inotify)
 132    * + closure->n_guards is const during PRE_NOTIFY & POST_NOTIFY
 133    * + closure->meta_marshal is const for all cases
 134    * + none of the callbacks can cause recursion
 135    * + closure->n_inotifiers is const 0 during FNOTIFY
 136    */
 137   switch (notify_type)
 138     {
 139       GClosureNotifyData *ndata;
 140       guint i, offs;
 141     case FNOTIFY:
 142       CLOSURE_READ_BITS (closure, &bits);
 143       while (bits.n_fnotifiers)
 144         {
 145           register guint n = --bits.n_fnotifiers;
 146
 147           ndata = closure->notifiers + CLOSURE_N_MFUNCS (&bits) + n;
 148           closure->marshal = (GClosureMarshal) ndata->notify;
 149           closure->data = ndata->data;
 150           ndata->notify (ndata->data, closure);
 151         }
 152       closure->marshal = NULL;
 153       closure->data = NULL;
 154       break;
 155     case INOTIFY:
 156       do {
 157         CLOSURE_READ_BITS2 (closure, &bits, &new);
 158         new.in_inotify = TRUE;
 159       }
 160       while (!CLOSURE_SWAP_BITS (closure, &bits,  &new));
 161
 162       while (bits.n_inotifiers)
 163         {
 164           register guint n = --bits.n_inotifiers;
 165
 166           ndata = closure->notifiers + CLOSURE_N_MFUNCS (&bits) + bits.n_fnotifiers + n;
 167           closure->marshal = (GClosureMarshal) ndata->notify;
 168           closure->data = ndata->data;
 169           ndata->notify (ndata->data, closure);
 170         }
 171       closure->marshal = NULL;
 172       closure->data = NULL;
 173       do {
 174         CLOSURE_READ_BITS2 (closure, &bits, &new);
 175         new.n_inotifiers = 0;
 176         new.in_inotify = FALSE;
 177       }
 178       while (!CLOSURE_SWAP_BITS (closure, &bits, &new));
 179       break;
 180     case PRE_NOTIFY:
 181       CLOSURE_READ_BITS (closure, &bits);
 182       i = bits.n_guards;
 183       offs = bits.meta_marshal;
 184       while (i--)
 185         {
 186           ndata = closure->notifiers + offs + i;
 187           ndata->notify (ndata->data, closure);
 188         }
 189       break;
 190     case POST_NOTIFY:
 191       CLOSURE_READ_BITS (closure, &bits);
 192       i = bits.n_guards;
 193       offs = bits.meta_marshal + i;
 194       while (i--)
 195         {
 196           ndata = closure->notifiers + offs + i;
 197           ndata->notify (ndata->data, closure);
 198         }
 199       break;
 200     }
 201 }
 202
 203 void
 204 g_closure_set_meta_marshal (GClosure       *closure,
 205                             gpointer        marshal_data,
 206                             GClosureMarshal meta_marshal)
 207 {
 208   GClosureNotifyData *old_notifiers, *new_notifiers;
 209   guint n;
 210   GClosure old, new;
 211
 212   g_return_if_fail (closure != NULL);
 213   g_return_if_fail (meta_marshal != NULL);
 214
 215 retry:
 216   CLOSURE_READ_BITS2 (closure, &old, &new);
 217
 218   g_return_if_fail (old.is_invalid == FALSE);
 219   g_return_if_fail (old.in_marshal == FALSE);
 220   g_return_if_fail (old.meta_marshal == 0);
 221
 222   n = CLOSURE_N_NOTIFIERS (&old);
 223
 224   old_notifiers = closure->notifiers;
 225   new_notifiers = g_renew (GClosureNotifyData, NULL, n + 1);
 226   if (old_notifiers)
 227     {
 228       /* usually the meta marshal will be setup right after creation, so the
 229        * g_memmove() should be rare-case scenario
 230        */
 231       g_memmove (new_notifiers + 1, old_notifiers, n * sizeof (old_notifiers[0]));
 232     }
 233   new_notifiers[0].data = marshal_data;
 234   new_notifiers[0].notify = (GClosureNotify) meta_marshal;
 235
 236   new.meta_marshal = 1;
 237
 238   /* this cannot be made atomic, as soon as we switch on the meta_marshal
 239    * bit, another thread could use the notifier while we have not yet
 240    * copied it. the safest is to install the new_notifiers first and then
 241    * switch on the meta_marshal flag. */
 242   closure->notifiers = new_notifiers;
 243
 244   if (!CLOSURE_SWAP_BITS (closure, &old, &new)) {
 245     g_free (new_notifiers);
 246     goto retry;
 247   }
 248
 249   g_free (old_notifiers);
 250 }
 251
 252 void
 253 g_closure_add_marshal_guards (GClosure      *closure,
 254                               gpointer       pre_marshal_data,
 255                               GClosureNotify pre_marshal_notify,
 256                               gpointer       post_marshal_data,
 257                               GClosureNotify post_marshal_notify)
 258 {
 259   guint i;
 260   GClosure old, new;
 261   GClosureNotifyData *old_notifiers, *new_notifiers;
 262
 263   g_return_if_fail (closure != NULL);
 264   g_return_if_fail (pre_marshal_notify != NULL);
 265   g_return_if_fail (post_marshal_notify != NULL);
 266
 267 retry:
 268   CLOSURE_READ_BITS2 (closure,  &old,  &new);
 269
 270   g_return_if_fail (old.is_invalid == FALSE);
 271   g_return_if_fail (old.in_marshal == FALSE);
 272   g_return_if_fail (old.n_guards < CLOSURE_MAX_N_GUARDS);
 273
 274   old_notifiers = closure->notifiers;
 275   new_notifiers = g_renew (GClosureNotifyData, old_notifiers, CLOSURE_N_NOTIFIERS (&old) + 2);
 276   if (old.n_inotifiers)
 277     new_notifiers[(CLOSURE_N_MFUNCS (&old) +
 278                         old.n_fnotifiers +
 279                         old.n_inotifiers + 1)] = new_notifiers[(CLOSURE_N_MFUNCS (&old) +
 280                                                                           old.n_fnotifiers + 0)];
 281   if (old.n_inotifiers > 1)
 282     new_notifiers[(CLOSURE_N_MFUNCS (&old) +
 283                         old.n_fnotifiers +
 284                         old.n_inotifiers)] = new_notifiers[(CLOSURE_N_MFUNCS (&old) +
 285                                                                       old.n_fnotifiers + 1)];
 286   if (old.n_fnotifiers)
 287     new_notifiers[(CLOSURE_N_MFUNCS (&old) +
 288                         old.n_fnotifiers + 1)] = new_notifiers[CLOSURE_N_MFUNCS (&old) + 0];
 289   if (old.n_fnotifiers > 1)
 290     new_notifiers[(CLOSURE_N_MFUNCS (&old) +
 291                         old.n_fnotifiers)] = new_notifiers[CLOSURE_N_MFUNCS (&old) + 1];
 292   if (old.n_guards)
 293     new_notifiers[(old.meta_marshal +
 294                         old.n_guards +
 295                         old.n_guards + 1)] = new_notifiers[old.meta_marshal + old.n_guards];
 296   i = old.n_guards;
 297
 298   new.n_guards = i+1;
 299
 300   new_notifiers[old.meta_marshal + i].data = pre_marshal_data;
 301   new_notifiers[old.meta_marshal + i].notify = pre_marshal_notify;
 302   new_notifiers[old.meta_marshal + i + 1].data = post_marshal_data;
 303   new_notifiers[old.meta_marshal + i + 1].notify = post_marshal_notify;
 304
 305   /* not really atomic */
 306   closure->notifiers = new_notifiers;
 307
 308   if (!CLOSURE_SWAP_BITS (closure, &old, &new))
 309     goto retry;
 310 }
 311
 312 void
 313 g_closure_add_finalize_notifier (GClosure      *closure,
 314                                  gpointer       notify_data,
 315                                  GClosureNotify notify_func)
 316 {
 317   guint i;
 318   GClosure old, new;
 319   GClosureNotifyData *old_notifiers, *new_notifiers;
 320
 321   g_return_if_fail (closure != NULL);
 322   g_return_if_fail (notify_func != NULL);
 323
 324 retry:
 325   CLOSURE_READ_BITS2 (closure, &old, &new);
 326
 327   g_return_if_fail (old.n_fnotifiers < CLOSURE_MAX_N_FNOTIFIERS);
 328
 329   old_notifiers = closure->notifiers;
 330   new_notifiers = g_renew (GClosureNotifyData, old_notifiers, CLOSURE_N_NOTIFIERS (&old) + 1);
 331   if (old.n_inotifiers)
 332     new_notifiers[(CLOSURE_N_MFUNCS (&old) +
 333                         old.n_fnotifiers +
 334                         old.n_inotifiers)] = new_notifiers[(CLOSURE_N_MFUNCS (&old) +
 335                                                                       old.n_fnotifiers + 0)];
 336   i = CLOSURE_N_MFUNCS (&old) + old.n_fnotifiers;
 337   new.n_fnotifiers++;
 338
 339   new_notifiers[i].data = notify_data;
 340   new_notifiers[i].notify = notify_func;
 341
 342   /* not really atomic */
 343   closure->notifiers = new_notifiers;
 344
 345   while (!CLOSURE_SWAP_BITS (closure, &old, &new))
 346     goto retry;
 347 }
 348
 349 void
 350 g_closure_add_invalidate_notifier (GClosure      *closure,
 351                                    gpointer       notify_data,
 352                                    GClosureNotify notify_func)
 353 {
 354   guint i;
 355   GClosure old, new;
 356   GClosureNotifyData *old_notifiers, *new_notifiers;
 357
 358   g_return_if_fail (closure != NULL);
 359   g_return_if_fail (notify_func != NULL);
 360
 361 retry:
 362   CLOSURE_READ_BITS2 (closure, &old, &new);
 363
 364   g_return_if_fail (old.is_invalid == FALSE);
 365   g_return_if_fail (old.n_inotifiers < CLOSURE_MAX_N_INOTIFIERS);
 366
 367   old_notifiers = closure->notifiers;
 368   new_notifiers = g_renew (GClosureNotifyData, old_notifiers, CLOSURE_N_NOTIFIERS (&old) + 1);
 369   i = CLOSURE_N_MFUNCS (&old) + old.n_fnotifiers + old.n_inotifiers;
 370   new.n_inotifiers++;
 371
 372   new_notifiers[i].data = notify_data;
 373   new_notifiers[i].notify = notify_func;
 374
 375   /* not really atomic */
 376   closure->notifiers = new_notifiers;
 377
 378   while (!CLOSURE_SWAP_BITS (closure, &old, &new))
 379     goto retry;
 380 }
 381
 382 static inline gboolean
 383 closure_try_remove_inotify (GClosure       *closure,
 384                             gpointer       notify_data,
 385                             GClosureNotify notify_func)
 386 {
 387   GClosureNotifyData *ndata, *nlast;
 388   GClosure old, new;
 389
 390 retry:
 391   CLOSURE_READ_BITS2 (closure, &old, &new);
 392
 393   nlast = closure->notifiers + CLOSURE_N_NOTIFIERS (&old) - 1;
 394   for (ndata = nlast + 1 - old.n_inotifiers; ndata <= nlast; ndata++)
 395     if (ndata->notify == notify_func && ndata->data == notify_data)
 396       {
 397         new.n_inotifiers -= 1;
 398         if (!CLOSURE_SWAP_BITS (closure, &old, &new))
 399           goto retry;
 400
 401         if (ndata < nlast)
 402           *ndata = *nlast;
 403
 404         return TRUE;
 405       }
 406   return FALSE;
 407 }
 408
 409 static inline gboolean
 410 closure_try_remove_fnotify (GClosure       *closure,
 411                             gpointer       notify_data,
 412                             GClosureNotify notify_func)
 413 {
 414   GClosureNotifyData *ndata, *nlast;
 415   GClosure old, new;
 416
 417 retry:
 418   CLOSURE_READ_BITS2 (closure, &old, &new);
 419
 420   nlast = closure->notifiers + CLOSURE_N_NOTIFIERS (&old) - old.n_inotifiers - 1;
 421   for (ndata = nlast + 1 - old.n_fnotifiers; ndata <= nlast; ndata++)
 422     if (ndata->notify == notify_func && ndata->data == notify_data)
 423       {
 424         new.n_fnotifiers -= 1;
 425         if (!CLOSURE_SWAP_BITS (closure, &old, &new))
 426           goto retry;
 427
 428         if (ndata < nlast)
 429           *ndata = *nlast;
 430
 431         if (new.n_inotifiers)
 432           closure->notifiers[(CLOSURE_N_MFUNCS (&new) +
 433                               new.n_fnotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (&new) +
 434                                                                             new.n_fnotifiers +
 435                                                                             new.n_inotifiers)];
 436         return TRUE;
 437       }
 438   return FALSE;
 439 }
 440
 441 GClosure*
 442 g_closure_ref (GClosure *closure)
 443 {
 444   g_return_val_if_fail (closure != NULL, NULL);
 445   g_return_val_if_fail (closure->ref_count > 0, NULL);
 446   g_return_val_if_fail (closure->ref_count < CLOSURE_MAX_REF_COUNT, NULL);
 447
 448   CLOSURE_REF (closure);
 449
 450   return closure;
 451 }
 452
 453 void
 454 g_closure_invalidate (GClosure *closure)
 455 {
 456   GClosure old, new;
 457
 458   g_return_if_fail (closure != NULL);
 459
 460 retry:
 461   CLOSURE_READ_BITS2 (closure, &old, &new);
 462
 463   if (!old.is_invalid)
 464     {
 465       new.ref_count++;
 466       new.is_invalid = TRUE;
 467
 468       if (!CLOSURE_SWAP_BITS (closure, &old, &new))
 469         goto retry;
 470
 471       closure_invoke_notifiers (closure, INOTIFY);
 472       g_closure_unref (closure);
 473     }
 474 }
 475
 476 void
 477 g_closure_unref (GClosure *closure)
 478 {
 479   gboolean is_zero;
 480
 481   g_return_if_fail (closure != NULL);
 482   g_return_if_fail (closure->ref_count > 0);
 483
 484   CLOSURE_UNREF (closure, is_zero);
 485
 486   if (G_UNLIKELY (is_zero))
 487     {
 488       closure_invoke_notifiers (closure, FNOTIFY);
 489       g_free (closure->notifiers);
 490       g_free (closure);
 491     }
 492 }
 493
 494 void
 495 g_closure_sink (GClosure *closure)
 496 {
 497   GClosure old, new;
 498
 499   g_return_if_fail (closure != NULL);
 500   g_return_if_fail (closure->ref_count > 0);
 501
 502   /* floating is basically a kludge to avoid creating closures
 503    * with a ref_count of 0. so the intial ref_count a closure has
 504    * is unowned. with invoking g_closure_sink() code may
 505    * indicate that it takes over that intiial ref_count.
 506    */
 507 retry:
 508   CLOSURE_READ_BITS2 (closure, &old, &new);
 509
 510   if (old.floating)
 511     {
 512       new.floating = FALSE;
 513
 514       if (!CLOSURE_SWAP_BITS (closure, &old, &new))
 515         goto retry;
 516
 517       g_closure_unref (closure);
 518     }
 519 }
 520
 521 void
 522 g_closure_remove_invalidate_notifier (GClosure      *closure,
 523                                       gpointer       notify_data,
 524                                       GClosureNotify notify_func)
 525 {
 526   GClosure bits;
 527
 528   g_return_if_fail (closure != NULL);
 529   g_return_if_fail (notify_func != NULL);
 530
 531   CLOSURE_READ_BITS (closure, &bits);
 532
 533   if (bits.is_invalid && bits.in_inotify && /* account removal of notify_func() while its called */
 534       ((gpointer) closure->marshal) == ((gpointer) notify_func) && closure->data == notify_data)
 535     closure->marshal = NULL;
 536   else if (!closure_try_remove_inotify (closure, notify_data, notify_func))
 537     g_warning (G_STRLOC ": unable to remove uninstalled invalidation notifier: %p (%p)",
 538                notify_func, notify_data);
 539 }
 540
 541 void
 542 g_closure_remove_finalize_notifier (GClosure      *closure,
 543                                     gpointer       notify_data,
 544                                     GClosureNotify notify_func)
 545 {
 546   GClosure bits;
 547
 548   g_return_if_fail (closure != NULL);
 549   g_return_if_fail (notify_func != NULL);
 550
 551   CLOSURE_READ_BITS (closure, &bits);
 552
 553   if (bits.is_invalid && !bits.in_inotify && /* account removal of notify_func() while its called */
 554       ((gpointer) closure->marshal) == ((gpointer) notify_func) && closure->data == notify_data)
 555     closure->marshal = NULL;
 556   else if (!closure_try_remove_fnotify (closure, notify_data, notify_func))
 557     g_warning (G_STRLOC ": unable to remove uninstalled finalization notifier: %p (%p)",
 558                notify_func, notify_data);
 559 }
 560
 561 void
 562 g_closure_invoke (GClosure       *closure,
 563                   GValue /*out*/ *return_value,
 564                   guint           n_param_values,
 565                   const GValue   *param_values,
 566                   gpointer        invocation_hint)
 567 {
 568   GClosure old, new;
 569
 570   g_return_if_fail (closure != NULL);
 571
 572 retry:
 573   CLOSURE_READ_BITS2 (closure, &old, &new);
 574
 575   if (!old.is_invalid)
 576    {
 577       GClosureMarshal marshal;
 578       gpointer marshal_data;
 579       gboolean in_marshal = old.in_marshal;
 580       gboolean meta_marshal = old.meta_marshal;
 581
 582       g_return_if_fail (closure->marshal || meta_marshal);
 583
 584       new.ref_count++;
 585       new.in_marshal = TRUE;
 586
 587       if (!CLOSURE_SWAP_BITS (closure, &old, &new))
 588         goto retry;
 589
 590       if (meta_marshal)
 591         {
 592           marshal_data = closure->notifiers[0].data;
 593           marshal = (GClosureMarshal) closure->notifiers[0].notify;
 594         }
 595       else
 596         {
 597           marshal_data = NULL;
 598           marshal = closure->marshal;
 599         }
 600       if (!in_marshal)
 601         closure_invoke_notifiers (closure, PRE_NOTIFY);
 602
 603       marshal (closure,
 604                return_value,
 605                n_param_values, param_values,
 606                invocation_hint,
 607                marshal_data);
 608
 609       if (!in_marshal)
 610         closure_invoke_notifiers (closure, POST_NOTIFY);
 611
 612       do {
 613         CLOSURE_READ_BITS2 (closure, &old, &new);
 614         new.in_marshal = in_marshal;
 615         new.ref_count--;
 616       }
 617       while (!CLOSURE_SWAP_BITS (closure, &old, &new));
 618     }
 619 }
 620
 621 void
 622 g_closure_set_marshal (GClosure       *closure,
 623                        GClosureMarshal marshal)
 624 {
 625   g_return_if_fail (closure != NULL);
 626   g_return_if_fail (marshal != NULL);
 627
 628   if (closure->marshal && closure->marshal != marshal)
 629     g_warning ("attempt to override closure->marshal (%p) with new marshal (%p)",
 630                closure->marshal, marshal);
 631   else
 632     closure->marshal = marshal;
 633 }
 634
 635 GClosure*
 636 g_cclosure_new (GCallback      callback_func,
 637                 gpointer       user_data,
 638                 GClosureNotify destroy_data)
 639 {
 640   GClosure *closure;
 641
 642   g_return_val_if_fail (callback_func != NULL, NULL);
 643
 644   closure = g_closure_new_simple (sizeof (GCClosure), user_data);
 645   if (destroy_data)
 646     g_closure_add_finalize_notifier (closure, user_data, destroy_data);
 647   ((GCClosure*) closure)->callback = (gpointer) callback_func;
 648
 649   return closure;
 650 }
 651
 652 GClosure*
 653 g_cclosure_new_swap (GCallback      callback_func,
 654                      gpointer       user_data,
 655                      GClosureNotify destroy_data)
 656 {
 657   GClosure *closure;
 658
 659   g_return_val_if_fail (callback_func != NULL, NULL);
 660
 661   closure = g_closure_new_simple (sizeof (GCClosure), user_data);
 662   if (destroy_data)
 663     g_closure_add_finalize_notifier (closure, user_data, destroy_data);
 664   ((GCClosure*) closure)->callback = (gpointer) callback_func;
 665   closure->derivative_flag = TRUE;
 666
 667   return closure;
 668 }
 669
 670 static void
 671 g_type_class_meta_marshal (GClosure       *closure,
 672                            GValue /*out*/ *return_value,
 673                            guint           n_param_values,
 674                            const GValue   *param_values,
 675                            gpointer        invocation_hint,
 676                            gpointer        marshal_data)
 677 {
 678   GTypeClass *class;
 679   gpointer callback;
 680   /* GType itype = (GType) closure->data; */
 681   guint offset = GPOINTER_TO_UINT (marshal_data);
 682
 683   class = G_TYPE_INSTANCE_GET_CLASS (g_value_peek_pointer (param_values + 0), itype, GTypeClass);
 684   callback = G_STRUCT_MEMBER (gpointer, class, offset);
 685   if (callback)
 686     closure->marshal (closure,
 687                       return_value,
 688                       n_param_values, param_values,
 689                       invocation_hint,
 690                       callback);
 691 }
 692
 693 static void
 694 g_type_iface_meta_marshal (GClosure       *closure,
 695                            GValue /*out*/ *return_value,
 696                            guint           n_param_values,
 697                            const GValue   *param_values,
 698                            gpointer        invocation_hint,
 699                            gpointer        marshal_data)
 700 {
 701   GTypeClass *class;
 702   gpointer callback;
 703   GType itype = (GType) closure->data;
 704   guint offset = GPOINTER_TO_UINT (marshal_data);
 705
 706   class = G_TYPE_INSTANCE_GET_INTERFACE (g_value_peek_pointer (param_values + 0), itype, GTypeClass);
 707   callback = G_STRUCT_MEMBER (gpointer, class, offset);
 708   if (callback)
 709     closure->marshal (closure,
 710                       return_value,
 711                       n_param_values, param_values,
 712                       invocation_hint,
 713                       callback);
 714 }
 715
 716 GClosure*
 717 g_signal_type_cclosure_new (GType    itype,
 718                             guint    struct_offset)
 719 {
 720   GClosure *closure;
 721
 722   g_return_val_if_fail (G_TYPE_IS_CLASSED (itype) || G_TYPE_IS_INTERFACE (itype), NULL);
 723   g_return_val_if_fail (struct_offset >= sizeof (GTypeClass), NULL);
 724
 725   closure = g_closure_new_simple (sizeof (GClosure), (gpointer) itype);
 726   if (G_TYPE_IS_INTERFACE (itype))
 727     g_closure_set_meta_marshal (closure, GUINT_TO_POINTER (struct_offset), g_type_iface_meta_marshal);
 728   else
 729     g_closure_set_meta_marshal (closure, GUINT_TO_POINTER (struct_offset), g_type_class_meta_marshal);
 730
 731   return closure;
 732 }
 733
 734 #define __G_CLOSURE_C__
 735 #include "gobjectaliasdef.c"