gio.async_initable

Module for AsyncInitable interface

iface AsyncInitable AsyncInitableGidBuilderImpl

Types 2

gio.async_initable.AsyncInitable is an interface for asynchronously initializable objects.

This is the asynchronous version of gio.initable.Initable; it behaves the same in all ways except that initialization is asynchronous. For more details see the descriptions on gio.initable.Initable.

A class may implement both the gio.initable.Initable and gio.async_initable.AsyncInitable interfaces.

Users of objects implementing this are not intended to use the interface method directly; instead it will be used automatically in various ways. For C applications you generally just call gio.async_initable.AsyncInitable.newAsync directly, or indirectly via a foo_thing_new_async() wrapper. This will call gio.async_initable.AsyncInitable.initAsync under the covers, calling back with NULL and a set glib.error.ErrorWrap on failure.

A typical implementation might look something like this:

enum {
   NOT_INITIALIZED,
   INITIALIZING,
   INITIALIZED
};

static void
_foo_ready_cb (Foo *self)
{
  GList *l;

  self->priv->state = INITIALIZED;

  for (l = self->priv->init_results; l != NULL; l = l->next)
    {
      GTask *task = l->data;

      if (self->priv->success)
        g_task_return_boolean (task, TRUE);
      else
        g_task_return_new_error (task, ...);
      g_object_unref (task);
    }

  g_list_free (self->priv->init_results);
  self->priv->init_results = NULL;
}

static void
foo_init_async (GAsyncInitable       *initable,
                int                   io_priority,
                GCancellable         *cancellable,
                GAsyncReadyCallback   callback,
                gpointer              user_data)
{
  Foo *self = FOO (initable);
  GTask *task;

  task = g_task_new (initable, cancellable, callback, user_data);
  g_task_set_name (task, G_STRFUNC);

  switch (self->priv->state)
    {
      case NOT_INITIALIZED:
        _foo_get_ready (self);
        self->priv->init_results = g_list_append (self->priv->init_results,
                                                  task);
        self->priv->state = INITIALIZING;
        break;
      case INITIALIZING:
        self->priv->init_results = g_list_append (self->priv->init_results,
                                                  task);
        break;
      case INITIALIZED:
        if (!self->priv->success)
          g_task_return_new_error (task, ...);
        else
          g_task_return_boolean (task, TRUE);
        g_object_unref (task);
        break;
    }
}

static gboolean
foo_init_finish (GAsyncInitable       *initable,
                 GAsyncResult         *result,
                 GError              **error)
{
  g_return_val_if_fail (g_task_is_valid (result, initable), FALSE);

  return g_task_propagate_boolean (G_TASK (result), error);
}

static void
foo_async_initable_iface_init (gpointer g_iface,
                               gpointer data)
{
  GAsyncInitableIface *iface = g_iface;

  iface->init_async = foo_init_async;
  iface->init_finish = foo_init_finish;
}

Methods

GType _getGType()

void newvAsync(gobject.types.GType objectType,  uint  nParameters,  gobject.parameter.Parameter parameters,  int  ioPriority,  gio.cancellable.Cancellable cancellable =  null,  gio.types.AsyncReadyCallback callback =  null)

Helper function for constructing #GAsyncInitable object. This is similar to [gobject.object.ObjectWrap.newv] but also initializes the object asynchronously.

void initAsync(int  ioPriority,  gio.cancellable.Cancellable cancellable =  null,  gio.types.AsyncReadyCallback callback =  null)

Starts asynchronous initialization of the object implementing the interface. This must be done before any real use of the object after initial construction. If the object also implements #GInitable...

bool initFinish(gio.async_result.AsyncResult res)Finishes asynchronous initialization and returns the result. See [gio.async_initable.AsyncInitable.initAsync].

gobject.object.ObjectWrap newFinish(gio.async_result.AsyncResult res)Finishes the async construction for the various g_async_initable_new calls, returning the created object or null on error.

interfaceAsyncInitableGidBuilderImpl(T)

Fluent builder implementation template for gio.async_initable.AsyncInitable