gio/gasynchelper.c

   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
  39 static void
  40 async_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
  52 void
  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
  78 typedef struct
  79 {
  80   GSource source;
  81   GPollFD pollfd;
  82   GCancellable *cancellable;
  83   gulong cancelled_tag;
  84 } FDSource;
  85
  86 static gboolean
  87 fd_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
  96 static gboolean
  97 fd_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
 106 static gboolean
 107 fd_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
 120 static void
 121 fd_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
 133 static 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 */
 141 static void
 142 fd_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
 149 GSource *
 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 }