AsyncInitable

`GAsyncInitable` is an interface for asynchronously initializable objects.

This is the asynchronous version of [iface@Gio.Initable]; it behaves the same in all ways except that initialization is asynchronous. For more details see the descriptions on `GInitable`.

A class may implement both the `GInitable` and `GAsyncInitable` 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 [func@Gio.AsyncInitable.new_async] directly, or indirectly via a foo_thing_new_async wrapper. This will call [method@Gio.AsyncInitable.init_async] under the covers, calling back with `NULL` and a set `GError` on failure.

A typical implementation might look something like this:

```c 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; } ```