1/* GIO - GLib Input, Output and Streaming Library
2 *
3 * Copyright (C) 2006-2007 Red Hat, Inc.
4 *
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.
9 *
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.
14 *
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.
19 *
20 * Author: Alexander Larsson <alexl@redhat.com>
21 */
22
23#include "config.h"
24
25#include "gasynchelper.h"
26
27#include "gioalias.h"
28
29/**
30 * SECTION:gasynchelper
31 * @short_description: Asynchronous Helper Functions
32 * @include: gio/gio.h
33 * @see_also: #GAsyncReady
34 *
35 * Provides helper functions for asynchronous operations.
36 *
37 **/
38
39static void
40async_result_free (gpointer data)
41{
42  GAsyncResultData *res = data;
43
44  if (res->error)
45    g_error_free (res->error);
46
47  g_object_unref (res->async_object);
48
49  g_free (res);
50}
51
52void
53_g_queue_async_result (GAsyncResultData *result,
54		       gpointer          async_object,
55		       GError           *error,
56		       gpointer          user_data,
57		       GSourceFunc       source_func)
58{
59  GSource *source;
60
61  g_return_if_fail (G_IS_OBJECT (async_object));
62
63  result->async_object = g_object_ref (async_object);
64  result->user_data = user_data;
65  result->error = error;
66
67  source = g_idle_source_new ();
68  g_source_set_priority (source, G_PRIORITY_DEFAULT);
69  g_source_set_callback (source, source_func, result, async_result_free);
70  g_source_attach (source, NULL);
71  g_source_unref (source);
72}
73
74/*************************************************************************
75 *             fd source                                                 *
76 ************************************************************************/
77
78typedef struct
79{
80  GSource source;
81  GPollFD pollfd;
82  GCancellable *cancellable;
83  gulong cancelled_tag;
84} FDSource;
85
86static gboolean
87fd_source_prepare (GSource *source,
88		   gint    *timeout)
89{
90  FDSource *fd_source = (FDSource *)source;
91  *timeout = -1;
92
93  return g_cancellable_is_cancelled (fd_source->cancellable);
94}
95
96static gboolean
97fd_source_check (GSource *source)
98{
99  FDSource *fd_source = (FDSource *)source;
100
101  return
102    g_cancellable_is_cancelled  (fd_source->cancellable) ||
103    fd_source->pollfd.revents != 0;
104}
105
106static gboolean
107fd_source_dispatch (GSource     *source,
108		    GSourceFunc  callback,
109		    gpointer     user_data)
110
111{
112  GFDSourceFunc func = (GFDSourceFunc)callback;
113  FDSource *fd_source = (FDSource *)source;
114
115  g_warn_if_fail (func != NULL);
116
117  return (*func) (user_data, fd_source->pollfd.revents, fd_source->pollfd.fd);
118}
119
120static void
121fd_source_finalize (GSource *source)
122{
123  FDSource *fd_source = (FDSource *)source;
124
125  if (fd_source->cancelled_tag)
126    g_signal_handler_disconnect (fd_source->cancellable,
127				 fd_source->cancelled_tag);
128
129  if (fd_source->cancellable)
130    g_object_unref (fd_source->cancellable);
131}
132
133static GSourceFuncs fd_source_funcs = {
134  fd_source_prepare,
135  fd_source_check,
136  fd_source_dispatch,
137  fd_source_finalize
138};
139
140/* Might be called on another thread */
141static void
142fd_source_cancelled_cb (GCancellable *cancellable,
143			gpointer      data)
144{
145  /* Wake up the mainloop in case we're waiting on async calls with FDSource */
146  g_main_context_wakeup (NULL);
147}
148
149GSource *
150_g_fd_source_new (int           fd,
151		  gushort       events,
152		  GCancellable *cancellable)
153{
154  GSource *source;
155  FDSource *fd_source;
156
157  source = g_source_new (&fd_source_funcs, sizeof (FDSource));
158  fd_source = (FDSource *)source;
159
160  if (cancellable)
161    fd_source->cancellable = g_object_ref (cancellable);
162
163  fd_source->pollfd.fd = fd;
164  fd_source->pollfd.events = events;
165  g_source_add_poll (source, &fd_source->pollfd);
166
167  if (cancellable)
168    fd_source->cancelled_tag =
169      g_signal_connect_data (cancellable, "cancelled",
170			     (GCallback)fd_source_cancelled_cb,
171			     NULL, NULL,
172			     0);
173
174  return source;
175}
176