* 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.
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* Author: Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include "gasyncresult.h"
+#include "gsimpleasyncresult.h"
#include "glibintl.h"
* SECTION:gasyncresult
* @short_description: Asynchronous Function Results
* @include: gio/gio.h
- * @see_also: #GSimpleAsyncResult
+ * @see_also: #GTask
*
* Provides a base class for implementing asynchronous function results.
*
* "enumerate children" operation). If the result or error status of the
* operation is not needed, there is no need to call the "_finish()"
* function; GIO will take care of cleaning up the result and error
- * information after the #GAsyncReadyCallback returns. Applications may
- * also take a reference to the #GAsyncResult and call "_finish()"
- * later; however, the "_finish()" function may be called at most once.
+ * information after the #GAsyncReadyCallback returns. You can pass
+ * %NULL for the #GAsyncReadyCallback if you don't need to take any
+ * action at all after the operation completes. Applications may also
+ * take a reference to the #GAsyncResult and call "_finish()" later;
+ * however, the "_finish()" function may be called at most once.
*
* Example of a typical asynchronous operation flow:
- * |[
+ * |[<!-- language="C" -->
* void _theoretical_frobnitz_async (Theoretical *t,
* GCancellable *c,
- * GAsyncReadyCallback *cb,
+ * GAsyncReadyCallback cb,
* gpointer u);
*
* gboolean _theoretical_frobnitz_finish (Theoretical *t,
* else
* g_printf ("Uh oh!\n");
*
- * /<!-- -->* ... *<!-- -->/
+ * ...
*
* }
*
* int main (int argc, void *argv[])
* {
- * /<!-- -->* ... *<!-- -->/
+ * ...
*
* _theoretical_frobnitz_async (theoretical_data,
* NULL,
* frobnitz_result_func,
* NULL);
*
- * /<!-- -->* ... *<!-- -->/
+ * ...
* }
* ]|
*
* always called, even in the case of a cancelled operation. On cancellation
* the result is a %G_IO_ERROR_CANCELLED error.
*
- * Some asynchronous operations are implemented using synchronous calls.
- * These are run in a separate thread, if #GThread has been initialized, but
- * otherwise they are sent to the Main Event Loop and processed in an idle
- * function. So, if you truly need asynchronous operations, make sure to
- * initialize #GThread.
- **/
+ * ## I/O Priority # {#io-priority}
+ *
+ * Many I/O-related asynchronous operations have a priority parameter,
+ * which is used in certain cases to determine the order in which
+ * operations are executed. They are not used to determine system-wide
+ * I/O scheduling. Priorities are integers, with lower numbers indicating
+ * higher priority. It is recommended to choose priorities between
+ * %G_PRIORITY_LOW and %G_PRIORITY_HIGH, with %G_PRIORITY_DEFAULT
+ * as a default.
+ */
typedef GAsyncResultIface GAsyncResultInterface;
G_DEFINE_INTERFACE (GAsyncResult, g_async_result, G_TYPE_OBJECT)
return (* iface->get_source_object) (res);
}
+
+/**
+ * g_async_result_legacy_propagate_error:
+ * @res: a #GAsyncResult
+ * @error: (out): a location to propagate the error to.
+ *
+ * If @res is a #GSimpleAsyncResult, this is equivalent to
+ * g_simple_async_result_propagate_error(). Otherwise it returns
+ * %FALSE.
+ *
+ * This can be used for legacy error handling in async *_finish()
+ * wrapper functions that traditionally handled #GSimpleAsyncResult
+ * error returns themselves rather than calling into the virtual method.
+ * This should not be used in new code; #GAsyncResult errors that are
+ * set by virtual methods should also be extracted by virtual methods,
+ * to enable subclasses to chain up correctly.
+ *
+ * Returns: %TRUE if @error is has been filled in with an error from
+ * @res, %FALSE if not.
+ *
+ * Since: 2.34
+ **/
+gboolean
+g_async_result_legacy_propagate_error (GAsyncResult *res,
+ GError **error)
+{
+ /* This doesn't use a vmethod, because it's only for code that used
+ * to use GSimpleAsyncResult. (But it's a GAsyncResult method so
+ * that callers don't need to worry about GSimpleAsyncResult
+ * deprecation warnings in the future.)
+ */
+
+ if (G_IS_SIMPLE_ASYNC_RESULT (res))
+ {
+ return g_simple_async_result_propagate_error (G_SIMPLE_ASYNC_RESULT (res),
+ error);
+ }
+ else
+ return FALSE;
+}
+
+/**
+ * g_async_result_is_tagged:
+ * @res: a #GAsyncResult
+ * @source_tag: an application-defined tag
+ *
+ * Checks if @res has the given @source_tag (generally a function
+ * pointer indicating the function @res was created by).
+ *
+ * Returns: %TRUE if @res has the indicated @source_tag, %FALSE if
+ * not.
+ *
+ * Since: 2.34
+ **/
+gboolean
+g_async_result_is_tagged (GAsyncResult *res,
+ gpointer source_tag)
+{
+ GAsyncResultIface *iface;
+
+ g_return_val_if_fail (G_IS_ASYNC_RESULT (res), FALSE);
+
+ iface = G_ASYNC_RESULT_GET_IFACE (res);
+
+ if (!iface->is_tagged)
+ return FALSE;
+
+ return (* iface->is_tagged) (res, source_tag);
+}
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