/* GObject - GLib Type, Object, Parameter and Signal Library * Copyright (C) 2000-2001 Red Hat, Inc. * Copyright (C) 2005 Imendio AB * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General * Public License along with this library; if not, see . */ #ifndef __G_CLOSURE_H__ #define __G_CLOSURE_H__ #if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION) #error "Only can be included directly." #endif #include G_BEGIN_DECLS /* --- defines --- */ /** * G_CLOSURE_NEEDS_MARSHAL: * @closure: a #GClosure * * Check if the closure still needs a marshaller. See g_closure_set_marshal(). * * Returns: %TRUE if a #GClosureMarshal marshaller has not yet been set on * @closure. */ #define G_CLOSURE_NEEDS_MARSHAL(closure) (((GClosure*) (closure))->marshal == NULL) /** * G_CLOSURE_N_NOTIFIERS: * @cl: a #GClosure * * Get the total number of notifiers connected with the closure @cl. * The count includes the meta marshaller, the finalize and invalidate notifiers * and the marshal guards. Note that each guard counts as two notifiers. * See g_closure_set_meta_marshal(), g_closure_add_finalize_notifier(), * g_closure_add_invalidate_notifier() and g_closure_add_marshal_guards(). * * Returns: number of notifiers */ #define G_CLOSURE_N_NOTIFIERS(cl) (((cl)->n_guards << 1L) + \ (cl)->n_fnotifiers + (cl)->n_inotifiers) /** * G_CCLOSURE_SWAP_DATA: * @cclosure: a #GCClosure * * Checks whether the user data of the #GCClosure should be passed as the * first parameter to the callback. See g_cclosure_new_swap(). * * Returns: %TRUE if data has to be swapped. */ #define G_CCLOSURE_SWAP_DATA(cclosure) (((GClosure*) (cclosure))->derivative_flag) /** * G_CALLBACK: * @f: a function pointer. * * Cast a function pointer to a #GCallback. */ #define G_CALLBACK(f) ((GCallback) (f)) /* -- typedefs --- */ typedef struct _GClosure GClosure; typedef struct _GClosureNotifyData GClosureNotifyData; /** * GCallback: * * The type used for callback functions in structure definitions and function * signatures. This doesn't mean that all callback functions must take no * parameters and return void. The required signature of a callback function * is determined by the context in which is used (e.g. the signal to which it * is connected). Use G_CALLBACK() to cast the callback function to a #GCallback. */ typedef void (*GCallback) (void); /** * GClosureNotify: * @data: data specified when registering the notification callback * @closure: the #GClosure on which the notification is emitted * * The type used for the various notification callbacks which can be registered * on closures. */ typedef void (*GClosureNotify) (gpointer data, GClosure *closure); /** * GClosureMarshal: * @closure: the #GClosure to which the marshaller belongs * @return_value: (nullable): a #GValue to store the return * value. May be %NULL if the callback of @closure doesn't return a * value. * @n_param_values: the length of the @param_values array * @param_values: (array length=n_param_values): an array of * #GValues holding the arguments on which to invoke the * callback of @closure * @invocation_hint: (nullable): the invocation hint given as the * last argument to g_closure_invoke() * @marshal_data: (nullable): additional data specified when * registering the marshaller, see g_closure_set_marshal() and * g_closure_set_meta_marshal() * * The type used for marshaller functions. */ typedef void (*GClosureMarshal) (GClosure *closure, GValue *return_value, guint n_param_values, const GValue *param_values, gpointer invocation_hint, gpointer marshal_data); /** * GVaClosureMarshal: * @closure: the #GClosure to which the marshaller belongs * @return_value: (nullable): a #GValue to store the return * value. May be %NULL if the callback of @closure doesn't return a * value. * @instance: (type GObject.TypeInstance): the instance on which the closure is * invoked. * @args: va_list of arguments to be passed to the closure. * @marshal_data: (nullable): additional data specified when * registering the marshaller, see g_closure_set_marshal() and * g_closure_set_meta_marshal() * @n_params: the length of the @param_types array * @param_types: (array length=n_params): the #GType of each argument from * @args. * * This is the signature of va_list marshaller functions, an optional * marshaller that can be used in some situations to avoid * marshalling the signal argument into GValues. */ typedef void (* GVaClosureMarshal) (GClosure *closure, GValue *return_value, gpointer instance, va_list args, gpointer marshal_data, int n_params, GType *param_types); /** * GCClosure: * @closure: the #GClosure * @callback: the callback function * * A #GCClosure is a specialization of #GClosure for C function callbacks. */ typedef struct _GCClosure GCClosure; /* --- structures --- */ struct _GClosureNotifyData { gpointer data; GClosureNotify notify; }; /** * GClosure: * @in_marshal: Indicates whether the closure is currently being invoked with * g_closure_invoke() * @is_invalid: Indicates whether the closure has been invalidated by * g_closure_invalidate() * * A #GClosure represents a callback supplied by the programmer. */ struct _GClosure { /*< private >*/ volatile guint ref_count : 15; /* meta_marshal is not used anymore but must be zero for historical reasons as it was exposed in the G_CLOSURE_N_NOTIFIERS macro */ volatile guint meta_marshal_nouse : 1; volatile guint n_guards : 1; volatile guint n_fnotifiers : 2; /* finalization notifiers */ volatile guint n_inotifiers : 8; /* invalidation notifiers */ volatile guint in_inotify : 1; volatile guint floating : 1; /*< protected >*/ volatile guint derivative_flag : 1; /*< public >*/ volatile guint in_marshal : 1; volatile guint is_invalid : 1; /*< private >*/ void (*marshal) (GClosure *closure, GValue /*out*/ *return_value, guint n_param_values, const GValue *param_values, gpointer invocation_hint, gpointer marshal_data); /*< protected >*/ gpointer data; /*< private >*/ GClosureNotifyData *notifiers; /* invariants/constraints: * - ->marshal and ->data are _invalid_ as soon as ->is_invalid==TRUE * - invocation of all inotifiers occours prior to fnotifiers * - order of inotifiers is random * inotifiers may _not_ free/invalidate parameter values (e.g. ->data) * - order of fnotifiers is random * - each notifier may only be removed before or during its invocation * - reference counting may only happen prior to fnotify invocation * (in that sense, fnotifiers are really finalization handlers) */ }; /* closure for C function calls, callback() is the user function */ struct _GCClosure { GClosure closure; gpointer callback; }; /* --- prototypes --- */ GLIB_AVAILABLE_IN_ALL GClosure* g_cclosure_new (GCallback callback_func, gpointer user_data, GClosureNotify destroy_data); GLIB_AVAILABLE_IN_ALL GClosure* g_cclosure_new_swap (GCallback callback_func, gpointer user_data, GClosureNotify destroy_data); GLIB_AVAILABLE_IN_ALL GClosure* g_signal_type_cclosure_new (GType itype, guint struct_offset); /* --- prototypes --- */ GLIB_AVAILABLE_IN_ALL GClosure* g_closure_ref (GClosure *closure); GLIB_AVAILABLE_IN_ALL void g_closure_sink (GClosure *closure); GLIB_AVAILABLE_IN_ALL void g_closure_unref (GClosure *closure); /* intimidating */ GLIB_AVAILABLE_IN_ALL GClosure* g_closure_new_simple (guint sizeof_closure, gpointer data); GLIB_AVAILABLE_IN_ALL void g_closure_add_finalize_notifier (GClosure *closure, gpointer notify_data, GClosureNotify notify_func); GLIB_AVAILABLE_IN_ALL void g_closure_remove_finalize_notifier (GClosure *closure, gpointer notify_data, GClosureNotify notify_func); GLIB_AVAILABLE_IN_ALL void g_closure_add_invalidate_notifier (GClosure *closure, gpointer notify_data, GClosureNotify notify_func); GLIB_AVAILABLE_IN_ALL void g_closure_remove_invalidate_notifier (GClosure *closure, gpointer notify_data, GClosureNotify notify_func); GLIB_AVAILABLE_IN_ALL void g_closure_add_marshal_guards (GClosure *closure, gpointer pre_marshal_data, GClosureNotify pre_marshal_notify, gpointer post_marshal_data, GClosureNotify post_marshal_notify); GLIB_AVAILABLE_IN_ALL void g_closure_set_marshal (GClosure *closure, GClosureMarshal marshal); GLIB_AVAILABLE_IN_ALL void g_closure_set_meta_marshal (GClosure *closure, gpointer marshal_data, GClosureMarshal meta_marshal); GLIB_AVAILABLE_IN_ALL void g_closure_invalidate (GClosure *closure); GLIB_AVAILABLE_IN_ALL void g_closure_invoke (GClosure *closure, GValue /*out*/ *return_value, guint n_param_values, const GValue *param_values, gpointer invocation_hint); /* FIXME: OK: data_object::destroy -> closure_invalidate(); MIS: closure_invalidate() -> disconnect(closure); MIS: disconnect(closure) -> (unlink) closure_unref(); OK: closure_finalize() -> g_free (data_string); random remarks: - need marshaller repo with decent aliasing to base types - provide marshaller collection, virtually covering anything out there */ GLIB_AVAILABLE_IN_ALL void g_cclosure_marshal_generic (GClosure *closure, GValue *return_gvalue, guint n_param_values, const GValue *param_values, gpointer invocation_hint, gpointer marshal_data); GLIB_AVAILABLE_IN_ALL void g_cclosure_marshal_generic_va (GClosure *closure, GValue *return_value, gpointer instance, va_list args_list, gpointer marshal_data, int n_params, GType *param_types); G_END_DECLS #endif /* __G_CLOSURE_H__ */