| /* GIO - GLib Input, Output and Streaming Library |
| * |
| * Copyright (C) 2006-2007 Red Hat, Inc. |
| * |
| * 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 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, write to the |
| * Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
| * Boston, MA 02111-1307, USA. |
| * |
| * Author: Alexander Larsson <alexl@redhat.com> |
| */ |
| |
| #include "config.h" |
| #include "gasyncresult.h" |
| #include "glibintl.h" |
| |
| #include "gioalias.h" |
| |
| /** |
| * SECTION:gasyncresult |
| * @short_description: Asynchronous Function Results |
| * @include: gio/gio.h |
| * @see_also: #GSimpleAsyncResult |
| * |
| * Provides a base class for implementing asynchronous function results. |
| * |
| * Asynchronous operations are broken up into two separate operations |
| * which are chained together by a #GAsyncReadyCallback. To begin |
| * an asynchronous operation, provide a #GAsyncReadyCallback to the |
| * asynchronous function. This callback will be triggered when the |
| * operation has completed, and will be passed a #GAsyncResult instance |
| * filled with the details of the operation's success or failure, the |
| * object the asynchronous function was started for and any error codes |
| * returned. The asynchronous callback function is then expected to call |
| * the corresponding "_finish()" function with the object the function |
| * was called for, and the #GAsyncResult instance, and optionally, |
| * an @error to grab any error conditions that may have occurred. |
| * |
| * The purpose of the "_finish()" function is to take the generic |
| * result of type #GAsyncResult and return the specific result |
| * that the operation in question yields (e.g. a #GFileEnumerator for |
| * a "enumerate children" operation). If the result or error status |
| * of the operation is not needed, there is no need to call the |
| * "_finish()" function, GIO will take care of cleaning up the |
| * result and error information after the #GAsyncReadyCallback |
| * returns. It is also allowed to take a reference to the #GAsyncResult and |
| * call "_finish()" later. |
| * |
| * Example of a typical asynchronous operation flow: |
| * |[ |
| * void _theoretical_frobnitz_async (Theoretical *t, |
| * GCancellable *c, |
| * GAsyncReadyCallback *cb, |
| * gpointer u); |
| * |
| * gboolean _theoretical_frobnitz_finish (Theoretical *t, |
| * GAsyncResult *res, |
| * GError **e); |
| * |
| * static void |
| * frobnitz_result_func (GObject *source_object, |
| * GAsyncResult *res, |
| * gpointer user_data) |
| * { |
| * gboolean success = FALSE; |
| * |
| * success = _theoretical_frobnitz_finish (source_object, res, NULL); |
| * |
| * if (success) |
| * g_printf ("Hurray!\n"); |
| * else |
| * g_printf ("Uh oh!\n"); |
| * |
| * /<!-- -->* ... *<!-- -->/ |
| * |
| * } |
| * |
| * int main (int argc, void *argv[]) |
| * { |
| * /<!-- -->* ... *<!-- -->/ |
| * |
| * _theoretical_frobnitz_async (theoretical_data, |
| * NULL, |
| * frobnitz_result_func, |
| * NULL); |
| * |
| * /<!-- -->* ... *<!-- -->/ |
| * } |
| * ]| |
| * |
| * The callback for an asynchronous operation is called only once, and is |
| * always called, even in the case of a cancelled operation. On cancellation |
| * the result is a %G_IO_ERROR_CANCELLED error. |
| * |
| * Some ascynchronous operations are implemented using synchronous calls. These |
| * are run in a separate thread, if #GThread has been initialized, but otherwise they |
| * are sent to the Main Event Loop and processed in an idle function. So, if you |
| * truly need asynchronous operations, make sure to initialize #GThread. |
| **/ |
| |
| static void g_async_result_base_init (gpointer g_class); |
| static void g_async_result_class_init (gpointer g_class, |
| gpointer class_data); |
| |
| GType |
| g_async_result_get_type (void) |
| { |
| static volatile gsize g_define_type_id__volatile = 0; |
| |
| if (g_once_init_enter (&g_define_type_id__volatile)) |
| { |
| const GTypeInfo async_result_info = |
| { |
| sizeof (GAsyncResultIface), /* class_size */ |
| g_async_result_base_init, /* base_init */ |
| NULL, /* base_finalize */ |
| g_async_result_class_init, |
| NULL, /* class_finalize */ |
| NULL, /* class_data */ |
| 0, |
| 0, /* n_preallocs */ |
| NULL |
| }; |
| GType g_define_type_id = |
| g_type_register_static (G_TYPE_INTERFACE, I_("GAsyncResult"), |
| &async_result_info, 0); |
| |
| g_type_interface_add_prerequisite (g_define_type_id, G_TYPE_OBJECT); |
| |
| g_once_init_leave (&g_define_type_id__volatile, g_define_type_id); |
| } |
| |
| return g_define_type_id__volatile; |
| } |
| |
| static void |
| g_async_result_class_init (gpointer g_class, |
| gpointer class_data) |
| { |
| } |
| |
| static void |
| g_async_result_base_init (gpointer g_class) |
| { |
| } |
| |
| /** |
| * g_async_result_get_user_data: |
| * @res: a #GAsyncResult. |
| * |
| * Gets the user data from a #GAsyncResult. |
| * |
| * Returns: the user data for @res. |
| **/ |
| gpointer |
| g_async_result_get_user_data (GAsyncResult *res) |
| { |
| GAsyncResultIface *iface; |
| |
| g_return_val_if_fail (G_IS_ASYNC_RESULT (res), NULL); |
| |
| iface = G_ASYNC_RESULT_GET_IFACE (res); |
| |
| return (* iface->get_user_data) (res); |
| } |
| |
| /** |
| * g_async_result_get_source_object: |
| * @res: a #GAsyncResult. |
| * |
| * Gets the source object from a #GAsyncResult. |
| * |
| * Returns: the source object for the @res. |
| **/ |
| GObject * |
| g_async_result_get_source_object (GAsyncResult *res) |
| { |
| GAsyncResultIface *iface; |
| |
| g_return_val_if_fail (G_IS_ASYNC_RESULT (res), NULL); |
| |
| iface = G_ASYNC_RESULT_GET_IFACE (res); |
| |
| return (* iface->get_source_object) (res); |
| } |
| |
| #define __G_ASYNC_RESULT_C__ |
| #include "gioaliasdef.c" |