text: /* 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 <sys/types.h>
  #include <sys/stat.h>
  #include <string.h>
  #include <errno.h>
  #include <fcntl.h>
  #ifdef HAVE_UNISTD_H
  #include <unistd.h>
  #endif
  
  #include "gsimpleasyncresult.h"
  #include "gasyncresult.h"
  #include "gcancellable.h"
  #include "gioscheduler.h"
  #include <gio/gioerror.h>
  #include "glibintl.h"
  
  
  /**
   * SECTION:gsimpleasyncresult
   * @short_description: Simple asynchronous results implementation
   * @include: gio/gio.h
   * @see_also: #GAsyncResult
   *
   * Implements #GAsyncResult for simple cases. Most of the time, this
   * will be all an application needs, and will be used transparently.
   * Because of this, #GSimpleAsyncResult is used throughout GIO for
   * handling asynchronous functions.
   *
   * GSimpleAsyncResult handles #GAsyncReadyCallback<!-- -->s, error
   * reporting, operation cancellation and the final state of an operation,
   * completely transparent to the application. Results can be returned
   * as a pointer e.g. for functions that return data that is collected
   * asynchronously, a boolean value for checking the success or failure
   * of an operation, or a #gssize for operations which return the number
   * of bytes modified by the operation; all of the simple return cases
   * are covered.
   *
   * Most of the time, an application will not need to know of the details
   * of this API; it is handled transparently, and any necessary operations
   * are handled by #GAsyncResult's interface. However, if implementing a
   * new GIO module, for writing language bindings, or for complex
   * applications that need better control of how asynchronous operations
   * are completed, it is important to understand this functionality.
   *
   * GSimpleAsyncResults are tagged with the calling function to ensure
   * that asynchronous functions and their finishing functions are used
   * together correctly.
   *
   * To create a new #GSimpleAsyncResult, call g_simple_async_result_new().
   * If the result needs to be created for a #GError, use
   * g_simple_async_result_new_from_error(). If a #GError is not available
   * (e.g. the asynchronous operation's doesn't take a #GError argument),
   * but the result still needs to be created for an error condition, use
   * g_simple_async_result_new_error() (or g_simple_async_result_set_error_va()
   * if your application or binding requires passing a variable argument list
   * directly), and the error can then be propagated through the use of
   * g_simple_async_result_propagate_error().
   *
   * An asynchronous operation can be made to ignore a cancellation event by
   * calling g_simple_async_result_set_handle_cancellation() with a
   * #GSimpleAsyncResult for the operation and %FALSE. This is useful for
   * operations that are dangerous to cancel, such as close (which would
   * cause a leak if cancelled before being run).
   *
   * GSimpleAsyncResult can integrate into GLib's event loop, #GMainLoop,
   * or it can use #GThread<!-- -->s if available.
   * g_simple_async_result_complete() will finish an I/O task directly
   * from the point where it is called. g_simple_async_result_complete_in_idle()
   * will finish it from an idle handler in the <link
   * linkend="g-main-context-push-thread-default">thread-default main
   * context</link>. g_simple_async_result_run_in_thread() will run the
   * job in a separate thread and then deliver the result to the
   * thread-default main context.
   *
   * To set the results of an asynchronous function,
   * g_simple_async_result_set_op_res_gpointer(),
   * g_simple_async_result_set_op_res_gboolean(), and
   * g_simple_async_result_set_op_res_gssize()
   * are provided, setting the operation's result to a gpointer, gboolean, or
   * gssize, respectively.
   *
   * Likewise, to get the result of an asynchronous function,
   * g_simple_async_result_get_op_res_gpointer(),
   * g_simple_async_result_get_op_res_gboolean(), and
   * g_simple_async_result_get_op_res_gssize() are
   * provided, getting the operation's result as a gpointer, gboolean, and
   * gssize, respectively.
   *
   * For the details of the requirements implementations must respect, see
   * #GAsyncResult.  A typical implementation of an asynchronous operation
   * using GSimpleAsyncResult looks something like this:
   *
   * |[
   * static void
   * baked_cb (Cake    *cake,
   *           gpointer user_data)
   * {
   *   /&ast; In this example, this callback is not given a reference to the cake, so
   *    &ast; the GSimpleAsyncResult has to take a reference to it.
   *    &ast;/
   *   GSimpleAsyncResult *result = user_data;
   *
   *   if (cake == NULL)
   *     g_simple_async_result_set_error (result,
   *                                      BAKER_ERRORS,
   *                                      BAKER_ERROR_NO_FLOUR,
   *                                      "Go to the supermarket");
   *   else
   *     g_simple_async_result_set_op_res_gpointer (result,
   *                                                g_object_ref (cake),
   *                                                g_object_unref);
   *
   *
   *   /&ast; In this example, we assume that baked_cb is called as a callback from
   *    &ast; the mainloop, so it's safe to complete the operation synchronously here.
   *    &ast; If, however, _baker_prepare_cake () might call its callback without
   *    &ast; first returning to the mainloop — inadvisable, but some APIs do so —
   *    &ast; we would need to use g_simple_async_result_complete_in_idle().
   *    &ast;/
   *   g_simple_async_result_complete (result);
   *   g_object_unref (result);
   * }
   *
   * void
   * baker_bake_cake_async (Baker              *self,
   *                        guint               radius,
   *                        GAsyncReadyCallback callback,
   *                        gpointer            user_data)
   * {
   *   GSimpleAsyncResult *simple;
   *   Cake               *cake;
   *
   *   if (radius < 3)
   *     {
   *       g_simple_async_report_error_in_idle (G_OBJECT (self),
   *                                            callback,
   *                                            user_data,
   *                                            BAKER_ERRORS,
   *                                            BAKER_ERROR_TOO_SMALL,
   *                                            "%ucm radius cakes are silly",
   *                                            radius);
   *       return;
   *     }
   *
   *   simple = g_simple_async_result_new (G_OBJECT (self),
   *                                       callback,
   *                                       user_data,
   *                                       baker_bake_cake_async);
   *   cake = _baker_get_cached_cake (self, radius);
   *
   *   if (cake != NULL)
   *     {
   *       g_simple_async_result_set_op_res_gpointer (simple,
   *                                                  g_object_ref (cake),
   *                                                  g_object_unref);
   *       g_simple_async_result_complete_in_idle (simple);
   *       g_object_unref (simple);
   *       /&ast; Drop the reference returned by _baker_get_cached_cake(); the
   *        &ast; GSimpleAsyncResult has taken its own reference.
   *        &ast;/
   *       g_object_unref (cake);
   *       return;
   *     }
   *
   *   _baker_prepare_cake (self, radius, baked_cb, user_data);
   * }
   *
   * Cake *
   * baker_bake_cake_finish (Baker        *self,
   *                         GAsyncResult *result,
   *                         GError      **error)
   * {
   *   GSimpleAsyncResult *simple;
   *   Cake               *cake;
   *
   *   g_return_val_if_fail (g_simple_async_result_is_valid (result,
   *                                                         G_OBJECT (self),
   *                                                         baker_bake_cake_async),
   *                         NULL);
   *
   *   simple = (GSimpleAsyncResult *) result;
   *
   *   if (g_simple_async_result_propagate_error (simple, error))
   *     return NULL;
   *
   *   cake = CAKE (g_simple_async_result_get_op_res_gpointer (simple));
   *   return g_object_ref (cake);
   * }
   * ]|
   */
  
  static void g_simple_async_result_async_result_iface_init (GAsyncResultIface       *iface);
  
  struct _GSimpleAsyncResult
  {
    GObject parent_instance;
  
    GObject *source_object;
    GAsyncReadyCallback callback;
    gpointer user_data;
    GMainContext *context;
    GError *error;
    gboolean failed;
    gboolean handle_cancellation;
  
    gpointer source_tag;
  
    union {
      gpointer v_pointer;
      gboolean v_boolean;
      gssize   v_ssize;
    } op_res;
  
    GDestroyNotify destroy_op_res;
  };
  
  struct _GSimpleAsyncResultClass
  {
    GObjectClass parent_class;
  };
  
  
  G_DEFINE_TYPE_WITH_CODE (GSimpleAsyncResult, g_simple_async_result, G_TYPE_OBJECT,
  			 G_IMPLEMENT_INTERFACE (G_TYPE_ASYNC_RESULT,
  						g_simple_async_result_async_result_iface_init))
  
  static void
  clear_op_res (GSimpleAsyncResult *simple)
  {
    if (simple->destroy_op_res)
      simple->destroy_op_res (simple->op_res.v_pointer);
    simple->destroy_op_res = NULL;
    simple->op_res.v_ssize = 0;
  }
  
  static void
  g_simple_async_result_finalize (GObject *object)
  {
    GSimpleAsyncResult *simple;
  
    simple = G_SIMPLE_ASYNC_RESULT (object);
  
    if (simple->source_object)
      g_object_unref (simple->source_object);
  
    if (simple->context)
      g_main_context_unref (simple->context);
  
    clear_op_res (simple);
  
    if (simple->error)
      g_error_free (simple->error);
  
    G_OBJECT_CLASS (g_simple_async_result_parent_class)->finalize (object);
  }
  
  static void
  g_simple_async_result_class_init (GSimpleAsyncResultClass *klass)
  {
    GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
   
    gobject_class->finalize = g_simple_async_result_finalize;
  }
  
  static void
  g_simple_async_result_init (GSimpleAsyncResult *simple)
  {
    simple->handle_cancellation = TRUE;
  
    simple->context = g_main_context_get_thread_default ();
    if (simple->context)
      g_main_context_ref (simple->context);
  }
  
  /**
   * g_simple_async_result_new:
   * @source_object: a #GObject the asynchronous function was called with,
   * or %NULL.
   * @callback: a #GAsyncReadyCallback.
   * @user_data: user data passed to @callback.
   * @source_tag: the asynchronous function.
   *
   * Creates a #GSimpleAsyncResult.
   *
   * Returns: a #GSimpleAsyncResult.
   **/
  GSimpleAsyncResult *
  g_simple_async_result_new (GObject             *source_object,
                             GAsyncReadyCallback  callback,
                             gpointer             user_data,
                             gpointer             source_tag)
  {
    GSimpleAsyncResult *simple;
  
    g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL);
  
    simple = g_object_new (G_TYPE_SIMPLE_ASYNC_RESULT, NULL);
    simple->callback = callback;
    if (source_object)
      simple->source_object = g_object_ref (source_object);
    else
      simple->source_object = NULL;
    simple->user_data = user_data;
    simple->source_tag = source_tag;
   
    return simple;
  }
  
  /**
   * g_simple_async_result_new_from_error:
   * @source_object: a #GObject, or %NULL.
   * @callback: a #GAsyncReadyCallback.
   * @user_data: user data passed to @callback.
   * @error: a #GError location.
   *
   * Creates a #GSimpleAsyncResult from an error condition.
   *
   * Returns: a #GSimpleAsyncResult.
   **/
  GSimpleAsyncResult *
  g_simple_async_result_new_from_error (GObject             *source_object,
                                        GAsyncReadyCallback  callback,
                                        gpointer             user_data,
                                        GError              *error)
  {
    GSimpleAsyncResult *simple;
  
    g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL);
  
    simple = g_simple_async_result_new (source_object,
  				      callback,
  				      user_data, NULL);
    g_simple_async_result_set_from_error (simple, error);
  
    return simple;
  }
  
  /**
   * g_simple_async_result_new_error:
   * @source_object: a #GObject, or %NULL.
   * @callback: a #GAsyncReadyCallback.
   * @user_data: user data passed to @callback.
   * @domain: a #GQuark.
   * @code: an error code.
   * @format: a string with format characters.
   * @...: a list of values to insert into @format.
   *
   * Creates a new #GSimpleAsyncResult with a set error.
   *
   * Returns: a #GSimpleAsyncResult.
   **/
  GSimpleAsyncResult *
  g_simple_async_result_new_error (GObject             *source_object,
                                   GAsyncReadyCallback  callback,
                                   gpointer             user_data,
                                   GQuark               domain,
                                   gint                 code,
                                   const char          *format,
                                   ...)
  {
    GSimpleAsyncResult *simple;
    va_list args;
   
    g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL);
    g_return_val_if_fail (domain != 0, NULL);
    g_return_val_if_fail (format != NULL, NULL);
  
    simple = g_simple_async_result_new (source_object,
  				      callback,
  				      user_data, NULL);
  
    va_start (args, format);
    g_simple_async_result_set_error_va (simple, domain, code, format, args);
    va_end (args);
   
    return simple;
  }
  
  
  static gpointer
  g_simple_async_result_get_user_data (GAsyncResult *res)
  {
    return G_SIMPLE_ASYNC_RESULT (res)->user_data;
  }
  
  static GObject *
  g_simple_async_result_get_source_object (GAsyncResult *res)
  {
    if (G_SIMPLE_ASYNC_RESULT (res)->source_object)
      return g_object_ref (G_SIMPLE_ASYNC_RESULT (res)->source_object);
    return NULL;
  }
  
  static void
  g_simple_async_result_async_result_iface_init (GAsyncResultIface *iface)
  {
    iface->get_user_data = g_simple_async_result_get_user_data;
    iface->get_source_object = g_simple_async_result_get_source_object;
  }
  
  /**
   * g_simple_async_result_set_handle_cancellation:
   * @simple: a #GSimpleAsyncResult.
   * @handle_cancellation: a #gboolean.
   *
   * Sets whether to handle cancellation within the asynchronous operation.
   *
   **/
  void
  g_simple_async_result_set_handle_cancellation (GSimpleAsyncResult *simple,
                                                 gboolean            handle_cancellation)
  {
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
    simple->handle_cancellation = handle_cancellation;
  }
  
  /**
   * g_simple_async_result_get_source_tag:
   * @simple: a #GSimpleAsyncResult.
   *
   * Gets the source tag for the #GSimpleAsyncResult.
   *
   * Returns: a #gpointer to the source object for the #GSimpleAsyncResult.
   **/
  gpointer
  g_simple_async_result_get_source_tag (GSimpleAsyncResult *simple)
  {
    g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), NULL);
    return simple->source_tag;
  }
  
  /**
   * g_simple_async_result_propagate_error:
   * @simple: a #GSimpleAsyncResult.
   * @dest: a location to propegate the error to.
   *
   * Propagates an error from within the simple asynchronous result to
   * a given destination.
   *
   * Returns: %TRUE if the error was propagated to @dest. %FALSE otherwise.
   **/
  gboolean
  g_simple_async_result_propagate_error (GSimpleAsyncResult  *simple,
                                         GError             **dest)
  {
    g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), FALSE);
  
    if (simple->failed)
      {
        g_propagate_error (dest, simple->error);
        simple->error = NULL;
        return TRUE;
      }
  
    return FALSE;
  }
  
  /**
   * g_simple_async_result_set_op_res_gpointer:
   * @simple: a #GSimpleAsyncResult.
   * @op_res: a pointer result from an asynchronous function.
   * @destroy_op_res: a #GDestroyNotify function.
   *
   * Sets the operation result within the asynchronous result to a pointer.
   **/
  void
  g_simple_async_result_set_op_res_gpointer (GSimpleAsyncResult *simple,
                                             gpointer            op_res,
                                             GDestroyNotify      destroy_op_res)
  {
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
  
    clear_op_res (simple);
    simple->op_res.v_pointer = op_res;
    simple->destroy_op_res = destroy_op_res;
  }
  
  /**
   * g_simple_async_result_get_op_res_gpointer:
   * @simple: a #GSimpleAsyncResult.
   *
   * Gets a pointer result as returned by the asynchronous function.
   *
   * Returns: a pointer from the result.
   **/
  gpointer
  g_simple_async_result_get_op_res_gpointer (GSimpleAsyncResult *simple)
  {
    g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), NULL);
    return simple->op_res.v_pointer;
  }
  
  /**
   * g_simple_async_result_set_op_res_gssize:
   * @simple: a #GSimpleAsyncResult.
   * @op_res: a #gssize.
   *
   * Sets the operation result within the asynchronous result to
   * the given @op_res.
   **/
  void
  g_simple_async_result_set_op_res_gssize (GSimpleAsyncResult *simple,
                                           gssize              op_res)
  {
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
    clear_op_res (simple);
    simple->op_res.v_ssize = op_res;
  }
  
  /**
   * g_simple_async_result_get_op_res_gssize:
   * @simple: a #GSimpleAsyncResult.
   *
   * Gets a gssize from the asynchronous result.
   *
   * Returns: a gssize returned from the asynchronous function.
   **/
  gssize
  g_simple_async_result_get_op_res_gssize (GSimpleAsyncResult *simple)
  {
    g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), 0);
    return simple->op_res.v_ssize;
  }
  
  /**
   * g_simple_async_result_set_op_res_gboolean:
   * @simple: a #GSimpleAsyncResult.
   * @op_res: a #gboolean.
   *
   * Sets the operation result to a boolean within the asynchronous result.
   **/
  void
  g_simple_async_result_set_op_res_gboolean (GSimpleAsyncResult *simple,
                                             gboolean            op_res)
  {
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
    clear_op_res (simple);
    simple->op_res.v_boolean = !!op_res;
  }
  
  /**
   * g_simple_async_result_get_op_res_gboolean:
   * @simple: a #GSimpleAsyncResult.
   *
   * Gets the operation result boolean from within the asynchronous result.
   *
   * Returns: %TRUE if the operation's result was %TRUE, %FALSE
   *     if the operation's result was %FALSE.
   **/
  gboolean
  g_simple_async_result_get_op_res_gboolean (GSimpleAsyncResult *simple)
  {
    g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), FALSE);
    return simple->op_res.v_boolean;
  }
  
  /**
   * g_simple_async_result_set_from_error:
   * @simple: a #GSimpleAsyncResult.
   * @error: #GError.
   *
   * Sets the result from a #GError.
   **/
  void
  g_simple_async_result_set_from_error (GSimpleAsyncResult *simple,
                                        const GError       *error)
  {
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
    g_return_if_fail (error != NULL);
  
    if (simple->error)
      g_error_free (simple->error);
    simple->error = g_error_copy (error);
    simple->failed = TRUE;
  }
  
  /**
   * g_simple_async_result_set_error_va:
   * @simple: a #GSimpleAsyncResult.
   * @domain: a #GQuark (usually #G_IO_ERROR).
   * @code: an error code.
   * @format: a formatted error reporting string.
   * @args: va_list of arguments.
   *
   * Sets an error within the asynchronous result without a #GError.
   * Unless writing a binding, see g_simple_async_result_set_error().
   **/
  void
  g_simple_async_result_set_error_va (GSimpleAsyncResult *simple,
                                      GQuark              domain,
                                      gint                code,
                                      const char         *format,
                                      va_list             args)
  {
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
    g_return_if_fail (domain != 0);
    g_return_if_fail (format != NULL);
  
    if (simple->error)
      g_error_free (simple->error);
    simple->error = g_error_new_valist (domain, code, format, args);
    simple->failed = TRUE;
  }
  
  /**
   * g_simple_async_result_set_error:
   * @simple: a #GSimpleAsyncResult.
   * @domain: a #GQuark (usually #G_IO_ERROR).
   * @code: an error code.
   * @format: a formatted error reporting string.
   * @...: a list of variables to fill in @format.
   *
   * Sets an error within the asynchronous result without a #GError.
   **/
  void
  g_simple_async_result_set_error (GSimpleAsyncResult *simple,
                                   GQuark              domain,
                                   gint                code,
                                   const char         *format,
                                   ...)
  {
    va_list args;
  
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
    g_return_if_fail (domain != 0);
    g_return_if_fail (format != NULL);
  
    va_start (args, format);
    g_simple_async_result_set_error_va (simple, domain, code, format, args);
    va_end (args);
  }
  
  /**
   * g_simple_async_result_complete:
   * @simple: a #GSimpleAsyncResult.
   *
   * Completes an asynchronous I/O job immediately. Must be called in
   * the thread where the asynchronous result was to be delivered, as it
   * invokes the callback directly. If you are in a different thread use
   * g_simple_async_result_complete_in_idle().
   *
   * Calling this function takes a reference to @simple for as long as
   * is needed to complete the call.
   **/
  void
  g_simple_async_result_complete (GSimpleAsyncResult *simple)
  {
  #ifndef G_DISABLE_CHECKS
    GSource *current_source;
    GMainContext *current_context;
  #endif
  
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
  
  #ifndef G_DISABLE_CHECKS
    current_source = g_main_current_source ();
    if (current_source && !g_source_is_destroyed (current_source))
      {
        current_context = g_source_get_context (current_source);
        if (current_context == g_main_context_default ())
  	current_context = NULL;
        if (simple->context != current_context)
  	g_warning ("g_simple_async_result_complete() called from wrong context!");
      }
  #endif
  
    if (simple->callback)
      simple->callback (simple->source_object,
  		      G_ASYNC_RESULT (simple),
  		      simple->user_data);
  }
  
  static gboolean
  complete_in_idle_cb (gpointer data)
  {
    GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (data);
  
    g_simple_async_result_complete (simple);
  
    return FALSE;
  }
  
  /**
   * g_simple_async_result_complete_in_idle:
   * @simple: a #GSimpleAsyncResult.
   *
   * Completes an asynchronous function in an idle handler in the <link
   * linkend="g-main-context-push-thread-default">thread-default main
   * loop</link> of the thread that @simple was initially created in.
   *
   * Calling this function takes a reference to @simple for as long as
   * is needed to complete the call.
   */
  void
  g_simple_async_result_complete_in_idle (GSimpleAsyncResult *simple)
  {
    GSource *source;
  
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
  
    g_object_ref (simple);
   
    source = g_idle_source_new ();
    g_source_set_priority (source, G_PRIORITY_DEFAULT);
    g_source_set_callback (source, complete_in_idle_cb, simple, g_object_unref);
  
    g_source_attach (source, simple->context);
    g_source_unref (source);
  }
  
  typedef struct {
    GSimpleAsyncResult *simple;
    GCancellable *cancellable;
    GSimpleAsyncThreadFunc func;
  } RunInThreadData;
  
  
  static gboolean
  complete_in_idle_cb_for_thread (gpointer _data)
  {
    RunInThreadData *data = _data;
    GSimpleAsyncResult *simple;
  
    simple = data->simple;
   
    if (simple->handle_cancellation &&
        g_cancellable_is_cancelled (data->cancellable))
      g_simple_async_result_set_error (simple,
                                       G_IO_ERROR,
                                       G_IO_ERROR_CANCELLED,
                                       "%s", _("Operation was cancelled"));
   
    g_simple_async_result_complete (simple);
  
    if (data->cancellable)
      g_object_unref (data->cancellable);
    g_object_unref (data->simple);
    g_free (data);
   
    return FALSE;
  }
  
  static gboolean
  run_in_thread (GIOSchedulerJob *job,
                 GCancellable    *c,
                 gpointer         _data)
  {
    RunInThreadData *data = _data;
    GSimpleAsyncResult *simple = data->simple;
    GSource *source;
   
    if (simple->handle_cancellation &&
        g_cancellable_is_cancelled (c))
      g_simple_async_result_set_error (simple,
                                       G_IO_ERROR,
                                       G_IO_ERROR_CANCELLED,
                                       "%s", _("Operation was cancelled"));
    else
      data->func (simple,
                  simple->source_object,
                  c);
  
    source = g_idle_source_new ();
    g_source_set_priority (source, G_PRIORITY_DEFAULT);
    g_source_set_callback (source, complete_in_idle_cb_for_thread, data, NULL);
  
    g_source_attach (source, simple->context);
    g_source_unref (source);
  
    return FALSE;
  }
  
  /**
   * g_simple_async_result_run_in_thread:
   * @simple: a #GSimpleAsyncResult.
   * @func: a #GSimpleAsyncThreadFunc.
   * @io_priority: the io priority of the request.
   * @cancellable: optional #GCancellable object, %NULL to ignore.
   *
   * Runs the asynchronous job in a separate thread and then calls
   * g_simple_async_result_complete_in_idle() on @simple to return
   * the result to the appropriate main loop.
   *
   * Calling this function takes a reference to @simple for as long as
   * is needed to run the job and report its completion.
   */
  void
  g_simple_async_result_run_in_thread (GSimpleAsyncResult     *simple,
                                       GSimpleAsyncThreadFunc  func,
                                       int                     io_priority,
                                       GCancellable           *cancellable)
  {
    RunInThreadData *data;
  
    g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
    g_return_if_fail (func != NULL);
  
    data = g_new (RunInThreadData, 1);
    data->func = func;
    data->simple = g_object_ref (simple);
    data->cancellable = cancellable;
    if (cancellable)
      g_object_ref (cancellable);
    g_io_scheduler_push_job (run_in_thread, data, NULL, io_priority, cancellable);
  }
  
  /**
   * g_simple_async_result_is_valid:
   * @result: the #GAsyncResult passed to the _finish function.
   * @source: the #GObject passed to the _finish function.
   * @source_tag: the asynchronous function.
   *
   * Ensures that the data passed to the _finish function of an async
   * operation is consistent.  Three checks are performed.
   *
   * First, @result is checked to ensure that it is really a
   * #GSimpleAsyncResult.  Second, @source is checked to ensure that it
   * matches the source object of @result.  Third, @source_tag is
   * checked to ensure that it is either %NULL (as it is when the result was
   * created by g_simple_async_report_error_in_idle() or
   * g_simple_async_report_gerror_in_idle()) or equal to the
   * @source_tag argument given to g_simple_async_result_new() (which, by
   * convention, is a pointer to the _async function corresponding to the
   * _finish function from which this function is called).
   *
   * Returns: #TRUE if all checks passed or #FALSE if any failed.
   **/
  gboolean
  g_simple_async_result_is_valid (GAsyncResult *result,
                                  GObject      *source,
                                  gpointer      source_tag)
  {
    GSimpleAsyncResult *simple;
    GObject *cmp_source;
  
    if (!G_IS_SIMPLE_ASYNC_RESULT (result))
      return FALSE;
    simple = (GSimpleAsyncResult *)result;
  
    cmp_source = g_async_result_get_source_object (result);
    if (cmp_source != source)
      {
        if (cmp_source != NULL)
          g_object_unref (cmp_source);
        return FALSE;
      }
    if (cmp_source != NULL)
      g_object_unref (cmp_source);
  
    return source_tag == NULL ||
           source_tag == g_simple_async_result_get_source_tag (simple);
  }
  
  /**
   * g_simple_async_report_error_in_idle:
   * @object: a #GObject.
   * @callback: a #GAsyncReadyCallback.
   * @user_data: user data passed to @callback.
   * @domain: a #GQuark containing the error domain (usually #G_IO_ERROR).
   * @code: a specific error code.
   * @format: a formatted error reporting string.
   * @...: a list of variables to fill in @format.
   *
   * Reports an error in an asynchronous function in an idle function by
   * directly setting the contents of the #GAsyncResult with the given error
   * information.
   **/
  void
  g_simple_async_report_error_in_idle (GObject             *object,
                                       GAsyncReadyCallback  callback,
                                       gpointer             user_data,
                                       GQuark               domain,
                                       gint                 code,
                                       const char          *format,
                                       ...)
  {
    GSimpleAsyncResult *simple;
    va_list args;
   
    g_return_if_fail (G_IS_OBJECT (object));
    g_return_if_fail (domain != 0);
    g_return_if_fail (format != NULL);
  
    simple = g_simple_async_result_new (object,
  				      callback,
  				      user_data, NULL);
  
    va_start (args, format);
    g_simple_async_result_set_error_va (simple, domain, code, format, args);
    va_end (args);
    g_simple_async_result_complete_in_idle (simple);
    g_object_unref (simple);
  }
  
  /**
   * g_simple_async_report_gerror_in_idle:
   * @object: a #GObject.
   * @callback: a #GAsyncReadyCallback.
   * @user_data: user data passed to @callback.
   * @error: the #GError to report
   *
   * Reports an error in an idle function. Similar to
   * g_simple_async_report_error_in_idle(), but takes a #GError rather
   * than building a new one.
   **/
  void
  g_simple_async_report_gerror_in_idle (GObject *object,
  				      GAsyncReadyCallback callback,
  				      gpointer user_data,
  				      GError *error)
  {
    GSimpleAsyncResult *simple;
   
    g_return_if_fail (G_IS_OBJECT (object));
    g_return_if_fail (error != NULL);
  
    simple = g_simple_async_result_new_from_error (object,
  						 callback,
  						 user_data,
  						 error);
    g_simple_async_result_complete_in_idle (simple);
    g_object_unref (simple);
  }
  