1 /* GObject - GLib Type, Object, Parameter and Signal Library
2 * Copyright (C) 2000-2001 Red Hat, Inc.
3 * Copyright (C) 2005 Imendio AB
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
18 * Boston, MA 02111-1307, USA.
22 * MT safe with regards to reference counting.
31 #include "gobjectalias.h"
36 * @short_description: Functions as first-class objects
39 * A #GClosure represents a callback supplied by the programmer. It
40 * will generally comprise a function of some kind and a marshaller
41 * used to call it. It is the reponsibility of the marshaller to
42 * convert the arguments for the invocation from #GValue<!-- -->s into
43 * a suitable form, perform the callback on the converted arguments,
44 * and transform the return value back into a #GValue.
46 * In the case of C programs, a closure usually just holds a pointer
47 * to a function and maybe a data argument, and the marshaller
48 * converts between #GValue<!-- --> and native C types. The GObject
49 * library provides the #GCClosure type for this purpose. Bindings for
50 * other languages need marshallers which convert between #GValue<!--
51 * -->s and suitable representations in the runtime of the language in
52 * order to use functions written in that languages as callbacks.
54 * Within GObject, closures play an important role in the
55 * implementation of signals. When a signal is registered, the
56 * @c_marshaller argument to g_signal_new() specifies the default C
57 * marshaller for any closure which is connected to this
58 * signal. GObject provides a number of C marshallers for this
59 * purpose, see the g_cclosure_marshal_*() functions. Additional C
60 * marshallers can be generated with the <link
61 * linkend="glib-genmarshal">glib-genmarshal</link> utility. Closures
62 * can be explicitly connected to signals with
63 * g_signal_connect_closure(), but it usually more convenient to let
64 * GObject create a closure automatically by using one of the
65 * g_signal_connect_*() functions which take a callback function/user
68 * Using closures has a number of important advantages over a simple
69 * callback function/data pointer combination:
72 * Closures allow the callee to get the types of the callback parameters,
73 * which means that language bindings don't have to write individual glue
74 * for each callback type.
77 * The reference counting of #GClosure makes it easy to handle reentrancy
78 * right; if a callback is removed while it is being invoked, the closure
79 * and its parameters won't be freed until the invocation finishes.
82 * g_closure_invalidate() and invalidation notifiers allow callbacks to be
83 * automatically removed when the objects they point to go away.
89 #define CLOSURE_MAX_REF_COUNT ((1 << 15) - 1)
90 #define CLOSURE_MAX_N_GUARDS ((1 << 1) - 1)
91 #define CLOSURE_MAX_N_FNOTIFIERS ((1 << 2) - 1)
92 #define CLOSURE_MAX_N_INOTIFIERS ((1 << 8) - 1)
93 #define CLOSURE_N_MFUNCS(cl) ((cl)->meta_marshal + \
94 ((cl)->n_guards << 1L))
95 /* same as G_CLOSURE_N_NOTIFIERS() (keep in sync) */
96 #define CLOSURE_N_NOTIFIERS(cl) (CLOSURE_N_MFUNCS (cl) + \
97 (cl)->n_fnotifiers + \
105 #define CHANGE_FIELD(_closure, _field, _OP, _value, _must_set, _SET_OLD, _SET_NEW) \
107 ClosureInt *cunion = (ClosureInt*) _closure; \
108 gint new_int, old_int, success; \
112 tmp.vint = old_int = cunion->vint; \
113 _SET_OLD tmp.closure._field; \
114 tmp.closure._field _OP _value; \
115 _SET_NEW tmp.closure._field; \
116 new_int = tmp.vint; \
117 success = g_atomic_int_compare_and_exchange (&cunion->vint, old_int, new_int); \
119 while (!success && _must_set); \
122 #define SWAP(_closure, _field, _value, _oldv) CHANGE_FIELD (_closure, _field, =, _value, TRUE, *(_oldv) =, (void) )
123 #define SET(_closure, _field, _value) CHANGE_FIELD (_closure, _field, =, _value, TRUE, (void), (void) )
124 #define INC(_closure, _field) CHANGE_FIELD (_closure, _field, +=, 1, TRUE, (void), (void) )
125 #define INC_ASSIGN(_closure, _field, _newv) CHANGE_FIELD (_closure, _field, +=, 1, TRUE, (void), *(_newv) = )
126 #define DEC(_closure, _field) CHANGE_FIELD (_closure, _field, -=, 1, TRUE, (void), (void) )
127 #define DEC_ASSIGN(_closure, _field, _newv) CHANGE_FIELD (_closure, _field, -=, 1, TRUE, (void), *(_newv) = )
129 #if 0 /* for non-thread-safe closures */
130 #define SWAP(cl,f,v,o) (void) (*(o) = cl->f, cl->f = v)
131 #define SET(cl,f,v) (void) (cl->f = v)
132 #define INC(cl,f) (void) (cl->f += 1)
133 #define INC_ASSIGN(cl,f,n) (void) (cl->f += 1, *(n) = cl->f)
134 #define DEC(cl,f) (void) (cl->f -= 1)
135 #define DEC_ASSIGN(cl,f,n) (void) (cl->f -= 1, *(n) = cl->f)
146 /* --- functions --- */
148 * g_closure_new_simple:
149 * @sizeof_closure: the size of the structure to allocate, must be at least
150 * <literal>sizeof (GClosure)</literal>
151 * @data: data to store in the @data field of the newly allocated #GClosure
153 * Allocates a struct of the given size and initializes the initial
154 * part as a #GClosure. This function is mainly useful when
155 * implementing new types of closures.
158 * typedef struct _MyClosure MyClosure;
162 * // extra data goes here
166 * my_closure_finalize (gpointer notify_data,
169 * MyClosure *my_closure = (MyClosure *)closure;
171 * // free extra data here
174 * MyClosure *my_closure_new (gpointer data)
177 * MyClosure *my_closure;
179 * closure = g_closure_new_simple (sizeof (MyClosure), data);
180 * my_closure = (MyClosure *) closure;
182 * // initialize extra data here
184 * g_closure_add_finalize_notifier (closure, notify_data,
185 * my_closure_finalize);
190 * Returns: a newly allocated #GClosure
193 g_closure_new_simple (guint sizeof_closure,
198 g_return_val_if_fail (sizeof_closure >= sizeof (GClosure), NULL);
200 closure = g_malloc0 (sizeof_closure);
201 SET (closure, ref_count, 1);
202 SET (closure, meta_marshal, 0);
203 SET (closure, n_guards, 0);
204 SET (closure, n_fnotifiers, 0);
205 SET (closure, n_inotifiers, 0);
206 SET (closure, in_inotify, FALSE);
207 SET (closure, floating, TRUE);
208 SET (closure, derivative_flag, 0);
209 SET (closure, in_marshal, FALSE);
210 SET (closure, is_invalid, FALSE);
211 closure->marshal = NULL;
212 closure->data = data;
213 closure->notifiers = NULL;
214 memset (G_STRUCT_MEMBER_P (closure, sizeof (*closure)), 0, sizeof_closure - sizeof (*closure));
220 closure_invoke_notifiers (GClosure *closure,
224 * meta_marshal n_guards n_guards n_fnotif. n_inotifiers
225 * ->[[meta_marshal][pre_guards][post_guards][fnotifiers][inotifiers]]
227 * CLOSURE_N_MFUNCS(cl) = meta_marshal + n_guards + n_guards;
228 * CLOSURE_N_NOTIFIERS(cl) = CLOSURE_N_MFUNCS(cl) + n_fnotifiers + n_inotifiers
230 * constrains/catches:
231 * - closure->notifiers may be reloacted during callback
232 * - closure->n_fnotifiers and closure->n_inotifiers may change during callback
233 * - i.e. callbacks can be removed/added during invocation
234 * - must prepare for callback removal during FNOTIFY and INOTIFY (done via ->marshal= & ->data=)
235 * - must distinguish (->marshal= & ->data=) for INOTIFY vs. FNOTIFY (via ->in_inotify)
236 * + closure->n_guards is const during PRE_NOTIFY & POST_NOTIFY
237 * + closure->meta_marshal is const for all cases
238 * + none of the callbacks can cause recursion
239 * + closure->n_inotifiers is const 0 during FNOTIFY
243 GClosureNotifyData *ndata;
246 while (closure->n_fnotifiers)
249 DEC_ASSIGN (closure, n_fnotifiers, &n);
251 ndata = closure->notifiers + CLOSURE_N_MFUNCS (closure) + n;
252 closure->marshal = (GClosureMarshal) ndata->notify;
253 closure->data = ndata->data;
254 ndata->notify (ndata->data, closure);
256 closure->marshal = NULL;
257 closure->data = NULL;
260 SET (closure, in_inotify, TRUE);
261 while (closure->n_inotifiers)
264 DEC_ASSIGN (closure, n_inotifiers, &n);
266 ndata = closure->notifiers + CLOSURE_N_MFUNCS (closure) + closure->n_fnotifiers + n;
267 closure->marshal = (GClosureMarshal) ndata->notify;
268 closure->data = ndata->data;
269 ndata->notify (ndata->data, closure);
271 closure->marshal = NULL;
272 closure->data = NULL;
273 SET (closure, in_inotify, FALSE);
276 i = closure->n_guards;
277 offs = closure->meta_marshal;
280 ndata = closure->notifiers + offs + i;
281 ndata->notify (ndata->data, closure);
285 i = closure->n_guards;
286 offs = closure->meta_marshal + i;
289 ndata = closure->notifiers + offs + i;
290 ndata->notify (ndata->data, closure);
297 * g_closure_set_meta_marshal:
298 * @closure: a #GClosure
299 * @marshal_data: context-dependent data to pass to @meta_marshal
300 * @meta_marshal: a #GClosureMarshal function
302 * Sets the meta marshaller of @closure. A meta marshaller wraps
303 * @closure->marshal and modifies the way it is called in some
304 * fashion. The most common use of this facility is for C callbacks.
305 * The same marshallers (generated by <link
306 * linkend="glib-genmarshal">glib-genmarshal</link>) are used
307 * everywhere, but the way that we get the callback function
308 * differs. In most cases we want to use @closure->callback, but in
309 * other cases we want to use some different technique to retrieve the
312 * For example, class closures for signals (see
313 * g_signal_type_cclosure_new()) retrieve the callback function from a
314 * fixed offset in the class structure. The meta marshaller retrieves
315 * the right callback and passes it to the marshaller as the
316 * @marshal_data argument.
319 g_closure_set_meta_marshal (GClosure *closure,
320 gpointer marshal_data,
321 GClosureMarshal meta_marshal)
323 GClosureNotifyData *notifiers;
325 g_return_if_fail (closure != NULL);
326 g_return_if_fail (meta_marshal != NULL);
327 g_return_if_fail (closure->is_invalid == FALSE);
328 g_return_if_fail (closure->in_marshal == FALSE);
329 g_return_if_fail (closure->meta_marshal == 0);
331 notifiers = closure->notifiers;
332 closure->notifiers = g_renew (GClosureNotifyData, NULL, CLOSURE_N_NOTIFIERS (closure) + 1);
335 /* usually the meta marshal will be setup right after creation, so the
336 * g_memmove() should be rare-case scenario
338 g_memmove (closure->notifiers + 1, notifiers, CLOSURE_N_NOTIFIERS (closure) * sizeof (notifiers[0]));
341 closure->notifiers[0].data = marshal_data;
342 closure->notifiers[0].notify = (GClosureNotify) meta_marshal;
343 SET (closure, meta_marshal, 1);
347 * g_closure_add_marshal_guards:
348 * @closure: a #GClosure
349 * @pre_marshal_data: data to pass to @pre_marshal_notify
350 * @pre_marshal_notify: a function to call before the closure callback
351 * @post_marshal_data: data to pass to @post_marshal_notify
352 * @post_marshal_notify: a function to call after the closure callback
354 * Adds a pair of notifiers which get invoked before and after the
355 * closure callback, respectively. This is typically used to protect
356 * the extra arguments for the duration of the callback. See
357 * g_object_watch_closure() for an example of marshal guards.
360 g_closure_add_marshal_guards (GClosure *closure,
361 gpointer pre_marshal_data,
362 GClosureNotify pre_marshal_notify,
363 gpointer post_marshal_data,
364 GClosureNotify post_marshal_notify)
368 g_return_if_fail (closure != NULL);
369 g_return_if_fail (pre_marshal_notify != NULL);
370 g_return_if_fail (post_marshal_notify != NULL);
371 g_return_if_fail (closure->is_invalid == FALSE);
372 g_return_if_fail (closure->in_marshal == FALSE);
373 g_return_if_fail (closure->n_guards < CLOSURE_MAX_N_GUARDS);
375 closure->notifiers = g_renew (GClosureNotifyData, closure->notifiers, CLOSURE_N_NOTIFIERS (closure) + 2);
376 if (closure->n_inotifiers)
377 closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
378 closure->n_fnotifiers +
379 closure->n_inotifiers + 1)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
380 closure->n_fnotifiers + 0)];
381 if (closure->n_inotifiers > 1)
382 closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
383 closure->n_fnotifiers +
384 closure->n_inotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
385 closure->n_fnotifiers + 1)];
386 if (closure->n_fnotifiers)
387 closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
388 closure->n_fnotifiers + 1)] = closure->notifiers[CLOSURE_N_MFUNCS (closure) + 0];
389 if (closure->n_fnotifiers > 1)
390 closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
391 closure->n_fnotifiers)] = closure->notifiers[CLOSURE_N_MFUNCS (closure) + 1];
392 if (closure->n_guards)
393 closure->notifiers[(closure->meta_marshal +
395 closure->n_guards + 1)] = closure->notifiers[closure->meta_marshal + closure->n_guards];
396 i = closure->n_guards;
397 closure->notifiers[closure->meta_marshal + i].data = pre_marshal_data;
398 closure->notifiers[closure->meta_marshal + i].notify = pre_marshal_notify;
399 closure->notifiers[closure->meta_marshal + i + 1].data = post_marshal_data;
400 closure->notifiers[closure->meta_marshal + i + 1].notify = post_marshal_notify;
401 INC (closure, n_guards);
405 * g_closure_add_finalize_notifier:
406 * @closure: a #GClosure
407 * @notify_data: data to pass to @notify_func
408 * @notify_func: the callback function to register
410 * Registers a finalization notifier which will be called when the
411 * reference count of @closure goes down to 0. Multiple finalization
412 * notifiers on a single closure are invoked in unspecified order. If
413 * a single call to g_closure_unref() results in the closure being
414 * both invalidated and finalized, then the invalidate notifiers will
415 * be run before the finalize notifiers.
418 g_closure_add_finalize_notifier (GClosure *closure,
419 gpointer notify_data,
420 GClosureNotify notify_func)
424 g_return_if_fail (closure != NULL);
425 g_return_if_fail (notify_func != NULL);
426 g_return_if_fail (closure->n_fnotifiers < CLOSURE_MAX_N_FNOTIFIERS);
428 closure->notifiers = g_renew (GClosureNotifyData, closure->notifiers, CLOSURE_N_NOTIFIERS (closure) + 1);
429 if (closure->n_inotifiers)
430 closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
431 closure->n_fnotifiers +
432 closure->n_inotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
433 closure->n_fnotifiers + 0)];
434 i = CLOSURE_N_MFUNCS (closure) + closure->n_fnotifiers;
435 closure->notifiers[i].data = notify_data;
436 closure->notifiers[i].notify = notify_func;
437 INC (closure, n_fnotifiers);
441 * g_closure_add_invalidate_notifier:
442 * @closure: a #GClosure
443 * @notify_data: data to pass to @notify_func
444 * @notify_func: the callback function to register
446 * Registers an invalidation notifier which will be called when the
447 * @closure is invalidated with g_closure_invalidate(). Invalidation
448 * notifiers are invoked before finalization notifiers, in an
452 g_closure_add_invalidate_notifier (GClosure *closure,
453 gpointer notify_data,
454 GClosureNotify notify_func)
458 g_return_if_fail (closure != NULL);
459 g_return_if_fail (notify_func != NULL);
460 g_return_if_fail (closure->is_invalid == FALSE);
461 g_return_if_fail (closure->n_inotifiers < CLOSURE_MAX_N_INOTIFIERS);
463 closure->notifiers = g_renew (GClosureNotifyData, closure->notifiers, CLOSURE_N_NOTIFIERS (closure) + 1);
464 i = CLOSURE_N_MFUNCS (closure) + closure->n_fnotifiers + closure->n_inotifiers;
465 closure->notifiers[i].data = notify_data;
466 closure->notifiers[i].notify = notify_func;
467 INC (closure, n_inotifiers);
470 static inline gboolean
471 closure_try_remove_inotify (GClosure *closure,
472 gpointer notify_data,
473 GClosureNotify notify_func)
475 GClosureNotifyData *ndata, *nlast;
477 nlast = closure->notifiers + CLOSURE_N_NOTIFIERS (closure) - 1;
478 for (ndata = nlast + 1 - closure->n_inotifiers; ndata <= nlast; ndata++)
479 if (ndata->notify == notify_func && ndata->data == notify_data)
481 DEC (closure, n_inotifiers);
490 static inline gboolean
491 closure_try_remove_fnotify (GClosure *closure,
492 gpointer notify_data,
493 GClosureNotify notify_func)
495 GClosureNotifyData *ndata, *nlast;
497 nlast = closure->notifiers + CLOSURE_N_NOTIFIERS (closure) - closure->n_inotifiers - 1;
498 for (ndata = nlast + 1 - closure->n_fnotifiers; ndata <= nlast; ndata++)
499 if (ndata->notify == notify_func && ndata->data == notify_data)
501 DEC (closure, n_fnotifiers);
504 if (closure->n_inotifiers)
505 closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
506 closure->n_fnotifiers)] = closure->notifiers[(CLOSURE_N_MFUNCS (closure) +
507 closure->n_fnotifiers +
508 closure->n_inotifiers)];
516 * @closure: #GClosure to increment the reference count on
518 * Increments the reference count on a closure to force it staying
519 * alive while the caller holds a pointer to it.
521 * Returns: The @closure passed in, for convenience
524 g_closure_ref (GClosure *closure)
527 g_return_val_if_fail (closure != NULL, NULL);
528 g_return_val_if_fail (closure->ref_count > 0, NULL);
529 g_return_val_if_fail (closure->ref_count < CLOSURE_MAX_REF_COUNT, NULL);
531 INC_ASSIGN (closure, ref_count, &new_ref_count);
532 g_return_val_if_fail (new_ref_count > 1, NULL);
538 * g_closure_invalidate:
539 * @closure: GClosure to invalidate
541 * Sets a flag on the closure to indicate that its calling
542 * environment has become invalid, and thus causes any future
543 * invocations of g_closure_invoke() on this @closure to be
544 * ignored. Also, invalidation notifiers installed on the closure will
545 * be called at this point. Note that unless you are holding a
546 * reference to the closure yourself, the invalidation notifiers may
547 * unref the closure and cause it to be destroyed, so if you need to
548 * access the closure after calling g_closure_invalidate(), make sure
549 * that you've previously called g_closure_ref().
551 * Note that g_closure_invalidate() will also be called when the
552 * reference count of a closure drops to zero (unless it has already
553 * been invalidated before).
556 g_closure_invalidate (GClosure *closure)
558 g_return_if_fail (closure != NULL);
560 if (!closure->is_invalid)
562 gboolean was_invalid;
563 g_closure_ref (closure); /* preserve floating flag */
564 SWAP (closure, is_invalid, TRUE, &was_invalid);
565 /* invalidate only once */
567 closure_invoke_notifiers (closure, INOTIFY);
568 g_closure_unref (closure);
574 * @closure: #GClosure to decrement the reference count on
576 * Decrements the reference count of a closure after it was previously
577 * incremented by the same caller. If no other callers are using the
578 * closure, then the closure will be destroyed and freed.
581 g_closure_unref (GClosure *closure)
585 g_return_if_fail (closure != NULL);
586 g_return_if_fail (closure->ref_count > 0);
588 if (closure->ref_count == 1) /* last unref, invalidate first */
589 g_closure_invalidate (closure);
591 DEC_ASSIGN (closure, ref_count, &new_ref_count);
593 if (new_ref_count == 0)
595 closure_invoke_notifiers (closure, FNOTIFY);
596 g_free (closure->notifiers);
603 * @closure: #GClosure to decrement the initial reference count on, if it's
606 * Takes over the initial ownership of a closure. Each closure is
607 * initially created in a <firstterm>floating</firstterm> state, which
608 * means that the initial reference count is not owned by any caller.
609 * g_closure_sink() checks to see if the object is still floating, and
610 * if so, unsets the floating state and decreases the reference
611 * count. If the closure is not floating, g_closure_sink() does
612 * nothing. The reason for the existance of the floating state is to
613 * prevent cumbersome code sequences like:
615 * closure = g_cclosure_new (cb_func, cb_data);
616 * g_source_set_closure (source, closure);
617 * g_closure_unref (closure); // XXX GObject doesn't really need this
619 * Because g_source_set_closure() (and similar functions) take ownership of the
620 * initial reference count, if it is unowned, we instead can write:
622 * g_source_set_closure (source, g_cclosure_new (cb_func, cb_data));
625 * Generally, this function is used together with g_closure_ref(). Ane example
626 * of storing a closure for later notification looks like:
628 * static GClosure *notify_closure = NULL;
630 * foo_notify_set_closure (GClosure *closure)
632 * if (notify_closure)
633 * g_closure_unref (notify_closure);
634 * notify_closure = closure;
635 * if (notify_closure)
637 * g_closure_ref (notify_closure);
638 * g_closure_sink (notify_closure);
643 * Because g_closure_sink() may decrement the reference count of a closure
644 * (if it hasn't been called on @closure yet) just like g_closure_unref(),
645 * g_closure_ref() should be called prior to this function.
648 g_closure_sink (GClosure *closure)
650 g_return_if_fail (closure != NULL);
651 g_return_if_fail (closure->ref_count > 0);
653 /* floating is basically a kludge to avoid creating closures
654 * with a ref_count of 0. so the intial ref_count a closure has
655 * is unowned. with invoking g_closure_sink() code may
656 * indicate that it takes over that intiial ref_count.
658 if (closure->floating)
660 gboolean was_floating;
661 SWAP (closure, floating, FALSE, &was_floating);
662 /* unref floating flag only once */
664 g_closure_unref (closure);
669 * g_closure_remove_invalidate_notifier:
670 * @closure: a #GClosure
671 * @notify_data: data which was passed to g_closure_add_invalidate_notifier()
672 * when registering @notify_func
673 * @notify_func: the callback function to remove
675 * Removes an invalidation notifier.
677 * Notice that notifiers are automatically removed after they are run.
680 g_closure_remove_invalidate_notifier (GClosure *closure,
681 gpointer notify_data,
682 GClosureNotify notify_func)
684 g_return_if_fail (closure != NULL);
685 g_return_if_fail (notify_func != NULL);
687 if (closure->is_invalid && closure->in_inotify && /* account removal of notify_func() while it's called */
688 ((gpointer) closure->marshal) == ((gpointer) notify_func) &&
689 closure->data == notify_data)
690 closure->marshal = NULL;
691 else if (!closure_try_remove_inotify (closure, notify_data, notify_func))
692 g_warning (G_STRLOC ": unable to remove uninstalled invalidation notifier: %p (%p)",
693 notify_func, notify_data);
697 * g_closure_remove_finalize_notifier:
698 * @closure: a #GClosure
699 * @notify_data: data which was passed to g_closure_add_finalize_notifier()
700 * when registering @notify_func
701 * @notify_func: the callback function to remove
703 * Removes a finalization notifier.
705 * Notice that notifiers are automatically removed after they are run.
708 g_closure_remove_finalize_notifier (GClosure *closure,
709 gpointer notify_data,
710 GClosureNotify notify_func)
712 g_return_if_fail (closure != NULL);
713 g_return_if_fail (notify_func != NULL);
715 if (closure->is_invalid && !closure->in_inotify && /* account removal of notify_func() while it's called */
716 ((gpointer) closure->marshal) == ((gpointer) notify_func) &&
717 closure->data == notify_data)
718 closure->marshal = NULL;
719 else if (!closure_try_remove_fnotify (closure, notify_data, notify_func))
720 g_warning (G_STRLOC ": unable to remove uninstalled finalization notifier: %p (%p)",
721 notify_func, notify_data);
726 * @closure: a #GClosure
727 * @return_value: a #GValue to store the return value. May be %NULL if the
728 * callback of @closure doesn't return a value.
729 * @n_param_values: the length of the @param_values array
730 * @param_values: an array of #GValue<!-- -->s holding the arguments on
731 * which to invoke the callback of @closure
732 * @invocation_hint: a context-dependent invocation hint
734 * Invokes the closure, i.e. executes the callback represented by the @closure.
737 g_closure_invoke (GClosure *closure,
738 GValue /*out*/ *return_value,
739 guint n_param_values,
740 const GValue *param_values,
741 gpointer invocation_hint)
743 g_return_if_fail (closure != NULL);
745 g_closure_ref (closure); /* preserve floating flag */
746 if (!closure->is_invalid)
748 GClosureMarshal marshal;
749 gpointer marshal_data;
750 gboolean in_marshal = closure->in_marshal;
752 g_return_if_fail (closure->marshal || closure->meta_marshal);
754 SET (closure, in_marshal, TRUE);
755 if (closure->meta_marshal)
757 marshal_data = closure->notifiers[0].data;
758 marshal = (GClosureMarshal) closure->notifiers[0].notify;
763 marshal = closure->marshal;
766 closure_invoke_notifiers (closure, PRE_NOTIFY);
769 n_param_values, param_values,
773 closure_invoke_notifiers (closure, POST_NOTIFY);
774 SET (closure, in_marshal, in_marshal);
776 g_closure_unref (closure);
780 * g_closure_set_marshal:
781 * @closure: a #GClosure
782 * @marshal: a #GClosureMarshal function
784 * Sets the marshaller of @closure. The <literal>marshal_data</literal>
785 * of @marshal provides a way for a meta marshaller to provide additional
786 * information to the marshaller. (See g_closure_set_meta_marshal().) For
787 * GObject's C predefined marshallers (the g_cclosure_marshal_*()
788 * functions), what it provides is a callback function to use instead of
789 * @closure->callback.
792 g_closure_set_marshal (GClosure *closure,
793 GClosureMarshal marshal)
795 g_return_if_fail (closure != NULL);
796 g_return_if_fail (marshal != NULL);
798 if (closure->marshal && closure->marshal != marshal)
799 g_warning ("attempt to override closure->marshal (%p) with new marshal (%p)",
800 closure->marshal, marshal);
802 closure->marshal = marshal;
807 * @callback_func: the function to invoke
808 * @user_data: user data to pass to @callback_func
809 * @destroy_data: destroy notify to be called when @user_data is no longer used
811 * Creates a new closure which invokes @callback_func with @user_data as
812 * the last parameter.
814 * Returns: a new #GCClosure
817 g_cclosure_new (GCallback callback_func,
819 GClosureNotify destroy_data)
823 g_return_val_if_fail (callback_func != NULL, NULL);
825 closure = g_closure_new_simple (sizeof (GCClosure), user_data);
827 g_closure_add_finalize_notifier (closure, user_data, destroy_data);
828 ((GCClosure*) closure)->callback = (gpointer) callback_func;
834 * g_cclosure_new_swap:
835 * @callback_func: the function to invoke
836 * @user_data: user data to pass to @callback_func
837 * @destroy_data: destroy notify to be called when @user_data is no longer used
839 * Creates a new closure which invokes @callback_func with @user_data as
840 * the first parameter.
842 * Returns: a new #GCClosure
845 g_cclosure_new_swap (GCallback callback_func,
847 GClosureNotify destroy_data)
851 g_return_val_if_fail (callback_func != NULL, NULL);
853 closure = g_closure_new_simple (sizeof (GCClosure), user_data);
855 g_closure_add_finalize_notifier (closure, user_data, destroy_data);
856 ((GCClosure*) closure)->callback = (gpointer) callback_func;
857 SET (closure, derivative_flag, TRUE);
863 g_type_class_meta_marshal (GClosure *closure,
864 GValue /*out*/ *return_value,
865 guint n_param_values,
866 const GValue *param_values,
867 gpointer invocation_hint,
868 gpointer marshal_data)
872 /* GType itype = (GType) closure->data; */
873 guint offset = GPOINTER_TO_UINT (marshal_data);
875 class = G_TYPE_INSTANCE_GET_CLASS (g_value_peek_pointer (param_values + 0), itype, GTypeClass);
876 callback = G_STRUCT_MEMBER (gpointer, class, offset);
878 closure->marshal (closure,
880 n_param_values, param_values,
886 g_type_iface_meta_marshal (GClosure *closure,
887 GValue /*out*/ *return_value,
888 guint n_param_values,
889 const GValue *param_values,
890 gpointer invocation_hint,
891 gpointer marshal_data)
895 GType itype = (GType) closure->data;
896 guint offset = GPOINTER_TO_UINT (marshal_data);
898 class = G_TYPE_INSTANCE_GET_INTERFACE (g_value_peek_pointer (param_values + 0), itype, GTypeClass);
899 callback = G_STRUCT_MEMBER (gpointer, class, offset);
901 closure->marshal (closure,
903 n_param_values, param_values,
909 * g_signal_type_cclosure_new:
910 * @itype: the #GType identifier of an interface or classed type
911 * @struct_offset: the offset of the member function of @itype's class
912 * structure which is to be invoked by the new closure
914 * Creates a new closure which invokes the function found at the offset
915 * @struct_offset in the class structure of the interface or classed type
916 * identified by @itype.
918 * Returns: a new #GCClosure
921 g_signal_type_cclosure_new (GType itype,
926 g_return_val_if_fail (G_TYPE_IS_CLASSED (itype) || G_TYPE_IS_INTERFACE (itype), NULL);
927 g_return_val_if_fail (struct_offset >= sizeof (GTypeClass), NULL);
929 closure = g_closure_new_simple (sizeof (GClosure), (gpointer) itype);
930 if (G_TYPE_IS_INTERFACE (itype))
931 g_closure_set_meta_marshal (closure, GUINT_TO_POINTER (struct_offset), g_type_iface_meta_marshal);
933 g_closure_set_meta_marshal (closure, GUINT_TO_POINTER (struct_offset), g_type_class_meta_marshal);
940 * g_cclosure_marshal_VOID__VOID:
941 * @closure: the #GClosure to which the marshaller belongs
942 * @return_value: ignored
944 * @param_values: a #GValue array holding only the instance
945 * @invocation_hint: the invocation hint given as the last argument
946 * to g_closure_invoke()
947 * @marshal_data: additional data specified when registering the marshaller
949 * A marshaller for a #GCClosure with a callback of type
950 * <literal>void (*callback) (gpointer instance, gpointer user_data)</literal>.
954 * g_cclosure_marshal_VOID__BOOLEAN:
955 * @closure: the #GClosure to which the marshaller belongs
956 * @return_value: ignored
958 * @param_values: a #GValue array holding the instance and the #gboolean parameter
959 * @invocation_hint: the invocation hint given as the last argument
960 * to g_closure_invoke()
961 * @marshal_data: additional data specified when registering the marshaller
963 * A marshaller for a #GCClosure with a callback of type
964 * <literal>void (*callback) (gpointer instance, gboolean arg1, gpointer user_data)</literal>.
968 * g_cclosure_marshal_VOID__CHAR:
969 * @closure: the #GClosure to which the marshaller belongs
970 * @return_value: ignored
972 * @param_values: a #GValue array holding the instance and the #gchar parameter
973 * @invocation_hint: the invocation hint given as the last argument
974 * to g_closure_invoke()
975 * @marshal_data: additional data specified when registering the marshaller
977 * A marshaller for a #GCClosure with a callback of type
978 * <literal>void (*callback) (gpointer instance, gchar arg1, gpointer user_data)</literal>.
982 * g_cclosure_marshal_VOID__UCHAR:
983 * @closure: the #GClosure to which the marshaller belongs
984 * @return_value: ignored
986 * @param_values: a #GValue array holding the instance and the #guchar parameter
987 * @invocation_hint: the invocation hint given as the last argument
988 * to g_closure_invoke()
989 * @marshal_data: additional data specified when registering the marshaller
991 * A marshaller for a #GCClosure with a callback of type
992 * <literal>void (*callback) (gpointer instance, guchar arg1, gpointer user_data)</literal>.
996 * g_cclosure_marshal_VOID__INT:
997 * @closure: the #GClosure to which the marshaller belongs
998 * @return_value: ignored
1000 * @param_values: a #GValue array holding the instance and the #gint parameter
1001 * @invocation_hint: the invocation hint given as the last argument
1002 * to g_closure_invoke()
1003 * @marshal_data: additional data specified when registering the marshaller
1005 * A marshaller for a #GCClosure with a callback of type
1006 * <literal>void (*callback) (gpointer instance, gint arg1, gpointer user_data)</literal>.
1010 * g_cclosure_marshal_VOID__UINT:
1011 * @closure: the #GClosure to which the marshaller belongs
1012 * @return_value: ignored
1013 * @n_param_values: 2
1014 * @param_values: a #GValue array holding the instance and the #guint parameter
1015 * @invocation_hint: the invocation hint given as the last argument
1016 * to g_closure_invoke()
1017 * @marshal_data: additional data specified when registering the marshaller
1019 * A marshaller for a #GCClosure with a callback of type
1020 * <literal>void (*callback) (gpointer instance, guint arg1, gpointer user_data)</literal>.
1024 * g_cclosure_marshal_VOID__LONG:
1025 * @closure: the #GClosure to which the marshaller belongs
1026 * @return_value: ignored
1027 * @n_param_values: 2
1028 * @param_values: a #GValue array holding the instance and the #glong parameter
1029 * @invocation_hint: the invocation hint given as the last argument
1030 * to g_closure_invoke()
1031 * @marshal_data: additional data specified when registering the marshaller
1033 * A marshaller for a #GCClosure with a callback of type
1034 * <literal>void (*callback) (gpointer instance, glong arg1, gpointer user_data)</literal>.
1038 * g_cclosure_marshal_VOID__ULONG:
1039 * @closure: the #GClosure to which the marshaller belongs
1040 * @return_value: ignored
1041 * @n_param_values: 2
1042 * @param_values: a #GValue array holding the instance and the #gulong parameter
1043 * @invocation_hint: the invocation hint given as the last argument
1044 * to g_closure_invoke()
1045 * @marshal_data: additional data specified when registering the marshaller
1047 * A marshaller for a #GCClosure with a callback of type
1048 * <literal>void (*callback) (gpointer instance, gulong arg1, gpointer user_data)</literal>.
1052 * g_cclosure_marshal_VOID__ENUM:
1053 * @closure: the #GClosure to which the marshaller belongs
1054 * @return_value: ignored
1055 * @n_param_values: 2
1056 * @param_values: a #GValue array holding the instance and the enumeration parameter
1057 * @invocation_hint: the invocation hint given as the last argument
1058 * to g_closure_invoke()
1059 * @marshal_data: additional data specified when registering the marshaller
1061 * A marshaller for a #GCClosure with a callback of type
1062 * <literal>void (*callback) (gpointer instance, gint arg1, gpointer user_data)</literal> where the #gint parameter denotes an enumeration type..
1066 * g_cclosure_marshal_VOID__FLAGS:
1067 * @closure: the #GClosure to which the marshaller belongs
1068 * @return_value: ignored
1069 * @n_param_values: 2
1070 * @param_values: a #GValue array holding the instance and the flags parameter
1071 * @invocation_hint: the invocation hint given as the last argument
1072 * to g_closure_invoke()
1073 * @marshal_data: additional data specified when registering the marshaller
1075 * A marshaller for a #GCClosure with a callback of type
1076 * <literal>void (*callback) (gpointer instance, gint arg1, gpointer user_data)</literal> where the #gint parameter denotes a flags type.
1080 * g_cclosure_marshal_VOID__FLOAT:
1081 * @closure: the #GClosure to which the marshaller belongs
1082 * @return_value: ignored
1083 * @n_param_values: 2
1084 * @param_values: a #GValue array holding the instance and the #gfloat parameter
1085 * @invocation_hint: the invocation hint given as the last argument
1086 * to g_closure_invoke()
1087 * @marshal_data: additional data specified when registering the marshaller
1089 * A marshaller for a #GCClosure with a callback of type
1090 * <literal>void (*callback) (gpointer instance, gfloat arg1, gpointer user_data)</literal>.
1094 * g_cclosure_marshal_VOID__DOUBLE:
1095 * @closure: the #GClosure to which the marshaller belongs
1096 * @return_value: ignored
1097 * @n_param_values: 2
1098 * @param_values: a #GValue array holding the instance and the #gdouble parameter
1099 * @invocation_hint: the invocation hint given as the last argument
1100 * to g_closure_invoke()
1101 * @marshal_data: additional data specified when registering the marshaller
1103 * A marshaller for a #GCClosure with a callback of type
1104 * <literal>void (*callback) (gpointer instance, gdouble arg1, gpointer user_data)</literal>.
1108 * g_cclosure_marshal_VOID__STRING:
1109 * @closure: the #GClosure to which the marshaller belongs
1110 * @return_value: ignored
1111 * @n_param_values: 2
1112 * @param_values: a #GValue array holding the instance and the #gchar* parameter
1113 * @invocation_hint: the invocation hint given as the last argument
1114 * to g_closure_invoke()
1115 * @marshal_data: additional data specified when registering the marshaller
1117 * A marshaller for a #GCClosure with a callback of type
1118 * <literal>void (*callback) (gpointer instance, const gchar *arg1, gpointer user_data)</literal>.
1122 * g_cclosure_marshal_VOID__PARAM:
1123 * @closure: the #GClosure to which the marshaller belongs
1124 * @return_value: ignored
1125 * @n_param_values: 2
1126 * @param_values: a #GValue array holding the instance and the #GParamSpec* parameter
1127 * @invocation_hint: the invocation hint given as the last argument
1128 * to g_closure_invoke()
1129 * @marshal_data: additional data specified when registering the marshaller
1131 * A marshaller for a #GCClosure with a callback of type
1132 * <literal>void (*callback) (gpointer instance, GParamSpec *arg1, gpointer user_data)</literal>.
1136 * g_cclosure_marshal_VOID__BOXED:
1137 * @closure: the #GClosure to which the marshaller belongs
1138 * @return_value: ignored
1139 * @n_param_values: 2
1140 * @param_values: a #GValue array holding the instance and the #GBoxed* parameter
1141 * @invocation_hint: the invocation hint given as the last argument
1142 * to g_closure_invoke()
1143 * @marshal_data: additional data specified when registering the marshaller
1145 * A marshaller for a #GCClosure with a callback of type
1146 * <literal>void (*callback) (gpointer instance, GBoxed *arg1, gpointer user_data)</literal>.
1150 * g_cclosure_marshal_VOID__POINTER:
1151 * @closure: the #GClosure to which the marshaller belongs
1152 * @return_value: ignored
1153 * @n_param_values: 2
1154 * @param_values: a #GValue array holding the instance and the #gpointer parameter
1155 * @invocation_hint: the invocation hint given as the last argument
1156 * to g_closure_invoke()
1157 * @marshal_data: additional data specified when registering the marshaller
1159 * A marshaller for a #GCClosure with a callback of type
1160 * <literal>void (*callback) (gpointer instance, gpointer arg1, gpointer user_data)</literal>.
1164 * g_cclosure_marshal_VOID__OBJECT:
1165 * @closure: the #GClosure to which the marshaller belongs
1166 * @return_value: ignored
1167 * @n_param_values: 2
1168 * @param_values: a #GValue array holding the instance and the #GObject* parameter
1169 * @invocation_hint: the invocation hint given as the last argument
1170 * to g_closure_invoke()
1171 * @marshal_data: additional data specified when registering the marshaller
1173 * A marshaller for a #GCClosure with a callback of type
1174 * <literal>void (*callback) (gpointer instance, GOBject *arg1, gpointer user_data)</literal>.
1178 * g_cclosure_marshal_VOID__UINT_POINTER:
1179 * @closure: the #GClosure to which the marshaller belongs
1180 * @return_value: ignored
1181 * @n_param_values: 3
1182 * @param_values: a #GValue array holding instance, arg1 and arg2
1183 * @invocation_hint: the invocation hint given as the last argument
1184 * to g_closure_invoke()
1185 * @marshal_data: additional data specified when registering the marshaller
1187 * A marshaller for a #GCClosure with a callback of type
1188 * <literal>void (*callback) (gpointer instance, guint arg1, gpointer arg2, gpointer user_data)</literal>.
1192 * g_cclosure_marshal_BOOLEAN__FLAGS:
1193 * @closure: the #GClosure to which the marshaller belongs
1194 * @return_value: a #GValue which can store the returned #gboolean
1195 * @n_param_values: 2
1196 * @param_values: a #GValue array holding instance and arg1
1197 * @invocation_hint: the invocation hint given as the last argument
1198 * to g_closure_invoke()
1199 * @marshal_data: additional data specified when registering the marshaller
1201 * A marshaller for a #GCClosure with a callback of type
1202 * <literal>gboolean (*callback) (gpointer instance, gint arg1, gpointer user_data)</literal> where the #gint parameter
1203 * denotes a flags type.
1207 * g_cclosure_marshal_BOOL__FLAGS:
1209 * Another name for g_cclosure_marshal_BOOLEAN__FLAGS().
1212 * g_cclosure_marshal_STRING__OBJECT_POINTER:
1213 * @closure: the #GClosure to which the marshaller belongs
1214 * @return_value: a #GValue, which can store the returned string
1215 * @n_param_values: 3
1216 * @param_values: a #GValue array holding instance, arg1 and arg2
1217 * @invocation_hint: the invocation hint given as the last argument
1218 * to g_closure_invoke()
1219 * @marshal_data: additional data specified when registering the marshaller
1221 * A marshaller for a #GCClosure with a callback of type
1222 * <literal>gchar* (*callback) (gpointer instance, GObject *arg1, gpointer arg2, gpointer user_data)</literal>.
1225 #define __G_CLOSURE_C__
1226 #include "gobjectaliasdef.c"