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
  28 /*< private >
  29  * SECTION:gasynchelper
  30  * @short_description: Asynchronous Helper Functions
  31  * @include: gio/gio.h
  32  * @see_also: #GAsyncReady
  33  *
  34  * Provides helper functions for asynchronous operations.
  35  *
  36  **/
  37
  38 /*************************************************************************
  39  *             fd source                                                 *
  40  ************************************************************************/
  41
  42 typedef struct
  43 {
  44   GSource source;
  45   GPollFD pollfd;
  46 } FDSource;
  47
  48 static gboolean
  49 fd_source_prepare (GSource *source,
  50                    gint    *timeout)
  51 {
  52   *timeout = -1;
  53   return FALSE;
  54 }
  55
  56 static gboolean
  57 fd_source_check (GSource *source)
  58 {
  59   FDSource *fd_source = (FDSource *)source;
  60
  61   return fd_source->pollfd.revents != 0;
  62 }
  63
  64 static gboolean
  65 fd_source_dispatch (GSource     *source,
  66                     GSourceFunc  callback,
  67                     gpointer     user_data)
  68
  69 {
  70   GFDSourceFunc func = (GFDSourceFunc)callback;
  71   FDSource *fd_source = (FDSource *)source;
  72
  73   g_warn_if_fail (func != NULL);
  74
  75   return (*func) (fd_source->pollfd.fd, fd_source->pollfd.revents, user_data);
  76 }
  77
  78 static void
  79 fd_source_finalize (GSource *source)
  80 {
  81 }
  82
  83 static gboolean
  84 fd_source_closure_callback (int           fd,
  85                             GIOCondition  condition,
  86                             gpointer      data)
  87 {
  88   GClosure *closure = data;
  89
  90   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
  91   GValue result_value = G_VALUE_INIT;
  92   gboolean result;
  93
  94   g_value_init (&result_value, G_TYPE_BOOLEAN);
  95
  96   g_value_init (&params[0], G_TYPE_INT);
  97   g_value_set_int (&params[0], fd);
  98
  99   g_value_init (&params[1], G_TYPE_IO_CONDITION);
 100   g_value_set_flags (&params[1], condition);
 101
 102   g_closure_invoke (closure, &result_value, 2, params, NULL);
 103
 104   result = g_value_get_boolean (&result_value);
 105   g_value_unset (&result_value);
 106   g_value_unset (&params[0]);
 107   g_value_unset (&params[1]);
 108
 109   return result;
 110 }
 111
 112 static void
 113 fd_source_closure_marshal (GClosure     *closure,
 114                            GValue       *return_value,
 115                            guint         n_param_values,
 116                            const GValue *param_values,
 117                            gpointer      invocation_hint,
 118                            gpointer      marshal_data)
 119 {
 120   GFDSourceFunc callback;
 121   GCClosure *cc = (GCClosure*) closure;
 122   gboolean v_return;
 123
 124   g_return_if_fail (return_value != NULL);
 125   g_return_if_fail (n_param_values == 0);
 126
 127   callback = (GFDSourceFunc) (marshal_data ? marshal_data : cc->callback);
 128
 129   v_return = callback (g_value_get_int (param_values),
 130                        g_value_get_flags (param_values + 1),
 131                        closure->data);
 132
 133   g_value_set_boolean (return_value, v_return);
 134 }
 135
 136 static GSourceFuncs fd_source_funcs = {
 137   fd_source_prepare,
 138   fd_source_check,
 139   fd_source_dispatch,
 140   fd_source_finalize,
 141   (GSourceFunc)fd_source_closure_callback,
 142   (GSourceDummyMarshal)fd_source_closure_marshal,
 143 };
 144
 145 GSource *
 146 _g_fd_source_new (int           fd,
 147                   gushort       events,
 148                   GCancellable *cancellable)
 149 {
 150   GSource *source;
 151   FDSource *fd_source;
 152
 153   source = g_source_new (&fd_source_funcs, sizeof (FDSource));
 154   fd_source = (FDSource *)source;
 155
 156   fd_source->pollfd.fd = fd;
 157   fd_source->pollfd.events = events;
 158   g_source_add_poll (source, &fd_source->pollfd);
 159
 160   if (cancellable)
 161     {
 162       GSource *cancellable_source = g_cancellable_source_new (cancellable);
 163
 164       g_source_set_dummy_callback (cancellable_source);
 165       g_source_add_child_source (source, cancellable_source);
 166       g_source_unref (cancellable_source);
 167     }
 168
 169   return source;
 170 }