[PATCH BlueZ v2] gdbus: Fix the ordering of signals
flat view
STALE3820d
From: Vinicius Costa Gomes <hidden>
Date: 2016-05-03 17:56:27
Subsystem:
the rest · Maintainer:
Linus Torvalds
Consider the following example: /foo properties: "A", "B" /bar properties: "C", "D" If during a given mainloop iteration, property "A" of object '/foo' is changed, then properties "C" and "D" of '/bar', lastly "B" of '/foo', the current code will emit the PropertiesChanged signals in following order: "A", "B", "C", "D". This may confuse applications that have a dependency on the order of those signals. This fixes the ordering, so in the example, the order becomes: "C", "D", "A", B". This is considered not to be a problem, as applications may use the flag G_DBUS_PROPERTY_CHANGED_FLAG_FLUSH, so property changed signals are emitted as soon as possible. The solution is for each object, to reschedule the signals every time a signal is emitted. --- gdbus/gdbus.h | 9 +++++++++ gdbus/object.c | 12 ++++++++++-- 2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/gdbus/gdbus.h b/gdbus/gdbus.h
index 69fbc10..e37385f 100644
--- a/gdbus/gdbus.h
+++ b/gdbus/gdbus.h@@ -302,6 +302,15 @@ void g_dbus_pending_property_error_valist(GDBusPendingReply id, const char *name, const char *format, va_list args); void g_dbus_pending_property_error(GDBusPendingReply id, const char *name, const char *format, ...); + +/* + * Note that when multiple properties for a given object path are changed + * in the same mainloop iteration, they will be grouped with the last + * property changed. If this behaviour is undesired, use + * g_dbus_emit_property_changed_full() with the + * G_DBUS_PROPERTY_CHANGED_FLAG_FLUSH flag, causing the signal to ignore + * any grouping. + */ void g_dbus_emit_property_changed(DBusConnection *connection, const char *path, const char *interface, const char *name);
diff --git a/gdbus/object.c b/gdbus/object.c
index a220101..afb4587 100644
--- a/gdbus/object.c
+++ b/gdbus/object.c@@ -635,11 +635,19 @@ static gboolean g_dbus_args_have_signature(const GDBusArgInfo *args, static void add_pending(struct generic_data *data) { - if (data->process_id > 0) - return; + guint old_id = data->process_id; data->process_id = g_idle_add(process_changes, data); + if (old_id > 0) { + /* + * If the element already had an old idler, remove the old one, + * no need to re-add it to the pending list. + */ + g_source_remove(old_id); + return; + } + pending = g_slist_append(pending, data); }
--
2.8.1