* 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 <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"
* SECTION:gsimpleasyncresult
* @short_description: Simple asynchronous results implementation
* @include: gio/gio.h
- * @see_also: #GAsyncResult
+ * @see_also: #GAsyncResult, #GTask
+ *
+ * As of GLib 2.36, #GSimpleAsyncResult is deprecated in favor of
+ * #GTask, which provides a simpler API.
*
- * 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 implements #GAsyncResult.
*
- * GSimpleAsyncResult handles #GAsyncReadyCallback<!-- -->s, error
+ * GSimpleAsyncResult handles #GAsyncReadyCallbacks, 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
* 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.
+ * or it can use #GThreads.
* 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
+ * will finish it from an idle handler in the
+ * [thread-default main context][g-main-context-push-thread-default]
+ * . 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.
*
* #GAsyncResult. A typical implementation of an asynchronous operation
* using GSimpleAsyncResult looks something like this:
*
- * |[
+ * |[<!-- language="C" -->
* static void
* baked_cb (Cake *cake,
* gpointer user_data)
* {
- * /* In this example, this callback is not given a reference to the cake, so
- * * the GSimpleAsyncResult has to take a reference to it.
- * */
+ * // In this example, this callback is not given a reference to the cake,
+ * // so the GSimpleAsyncResult has to take a reference to it.
* GSimpleAsyncResult *result = user_data;
*
* if (cake == NULL)
* g_object_unref);
*
*
- * /* In this example, we assume that baked_cb is called as a callback from
- * * the mainloop, so it's safe to complete the operation synchronously here.
- * * If, however, _baker_prepare_cake () might call its callback without
- * * first returning to the mainloop — inadvisable, but some APIs do so —
- * * we would need to use g_simple_async_result_complete_in_idle().
- * */
+ * // In this example, we assume that baked_cb is called as a callback from
+ * // the mainloop, so it's safe to complete the operation synchronously here.
+ * // If, however, _baker_prepare_cake () might call its callback without
+ * // first returning to the mainloop — inadvisable, but some APIs do so —
+ * // we would need to use g_simple_async_result_complete_in_idle().
* g_simple_async_result_complete (result);
* g_object_unref (result);
* }
* g_object_unref);
* g_simple_async_result_complete_in_idle (simple);
* g_object_unref (simple);
- * /* Drop the reference returned by _baker_get_cached_cake(); the
- * * GSimpleAsyncResult has taken its own reference.
- * */
+ * // Drop the reference returned by _baker_get_cached_cake();
+ * // the GSimpleAsyncResult has taken its own reference.
* g_object_unref (cake);
* return;
* }
GError *error;
gboolean failed;
gboolean handle_cancellation;
+ GCancellable *check_cancellable;
gpointer source_tag;
if (simple->source_object)
g_object_unref (simple->source_object);
- if (simple->context)
- g_main_context_unref (simple->context);
+ if (simple->check_cancellable)
+ g_object_unref (simple->check_cancellable);
+
+ g_main_context_unref (simple->context);
clear_op_res (simple);
{
simple->handle_cancellation = TRUE;
- simple->context = g_main_context_get_thread_default ();
- if (simple->context)
- g_main_context_ref (simple->context);
+ simple->context = g_main_context_ref_thread_default ();
}
/**
*
* Creates a #GSimpleAsyncResult.
*
+ * The common convention is to create the #GSimpleAsyncResult in the
+ * function that starts the asynchronous operation and use that same
+ * function as the @source_tag.
+ *
+ * If your operation supports cancellation with #GCancellable (which it
+ * probably should) then you should provide the user's cancellable to
+ * g_simple_async_result_set_check_cancellable() immediately after
+ * this function returns.
+ *
* Returns: a #GSimpleAsyncResult.
**/
GSimpleAsyncResult *
return NULL;
}
+static gboolean
+g_simple_async_result_is_tagged (GAsyncResult *res,
+ gpointer source_tag)
+{
+ return G_SIMPLE_ASYNC_RESULT (res)->source_tag == source_tag;
+}
+
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;
+ iface->is_tagged = g_simple_async_result_is_tagged;
}
/**
*
* Sets whether to handle cancellation within the asynchronous operation.
*
+ * This function has nothing to do with
+ * g_simple_async_result_set_check_cancellable(). It only refers to the
+ * #GCancellable passed to g_simple_async_result_run_in_thread().
**/
void
g_simple_async_result_set_handle_cancellation (GSimpleAsyncResult *simple,
* Propagates an error from within the simple asynchronous result to
* a given destination.
*
+ * If the #GCancellable given to a prior call to
+ * g_simple_async_result_set_check_cancellable() is cancelled then this
+ * function will return %TRUE with @dest set appropriately.
+ *
* Returns: %TRUE if the error was propagated to @dest. %FALSE otherwise.
**/
gboolean
{
g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), FALSE);
+ if (g_cancellable_set_error_if_cancelled (simple->check_cancellable, dest))
+ return TRUE;
+
if (simple->failed)
{
g_propagate_error (dest, simple->error);
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!");
}
* 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.
+ * Completes an asynchronous function in an idle handler in the
+ * [thread-default main context][g-main-context-push-thread-default]
+ * of the thread that @simple was initially created in
+ * (and re-pushes that context around the invocation of the callback).
*
* Calling this function takes a reference to @simple for as long as
* is needed to complete the call.
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_set_name (source, "[gio] complete_in_idle_cb");
g_source_attach (source, simple->context);
g_source_unref (source);
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_set_name (source, "[gio] complete_in_idle_cb_for_thread");
g_source_attach (source, simple->context);
g_source_unref (source);
data->cancellable = cancellable;
if (cancellable)
g_object_ref (cancellable);
+ G_GNUC_BEGIN_IGNORE_DEPRECATIONS;
g_io_scheduler_push_job (run_in_thread, data, NULL, io_priority, cancellable);
+ G_GNUC_END_IGNORE_DEPRECATIONS;
}
/**
* 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.
+ * @source: (allow-none): the #GObject passed to the _finish function.
+ * @source_tag: (allow-none): 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).
+ * checked to ensure that it is 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). (Alternatively, if either
+ * @source_tag or @result's source tag is %NULL, then the source tag
+ * check is skipped.)
*
* Returns: #TRUE if all checks passed or #FALSE if any failed.
*
{
GSimpleAsyncResult *simple;
GObject *cmp_source;
+ gpointer result_source_tag;
if (!G_IS_SIMPLE_ASYNC_RESULT (result))
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);
+ result_source_tag = g_simple_async_result_get_source_tag (simple);
+ return source_tag == NULL || result_source_tag == NULL ||
+ source_tag == result_source_tag;
}
/**
g_simple_async_result_complete_in_idle (simple);
g_object_unref (simple);
}
+
+/**
+ * g_simple_async_result_set_check_cancellable:
+ * @simple: a #GSimpleAsyncResult
+ * @check_cancellable: (allow-none): a #GCancellable to check, or %NULL to unset
+ *
+ * Sets a #GCancellable to check before dispatching results.
+ *
+ * This function has one very specific purpose: the provided cancellable
+ * is checked at the time of g_simple_async_result_propagate_error() If
+ * it is cancelled, these functions will return an "Operation was
+ * cancelled" error (%G_IO_ERROR_CANCELLED).
+ *
+ * Implementors of cancellable asynchronous functions should use this in
+ * order to provide a guarantee to their callers that cancelling an
+ * async operation will reliably result in an error being returned for
+ * that operation (even if a positive result for the operation has
+ * already been sent as an idle to the main context to be dispatched).
+ *
+ * The checking described above is done regardless of any call to the
+ * unrelated g_simple_async_result_set_handle_cancellation() function.
+ *
+ * Since: 2.32
+ **/
+void
+g_simple_async_result_set_check_cancellable (GSimpleAsyncResult *simple,
+ GCancellable *check_cancellable)
+{
+ g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
+ g_return_if_fail (check_cancellable == NULL || G_IS_CANCELLABLE (check_cancellable));
+
+ g_clear_object (&simple->check_cancellable);
+ if (check_cancellable)
+ simple->check_cancellable = g_object_ref (check_cancellable);
+}
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