[pulseaudio-discuss] [PATCH reserve 2/2] Initialize monitor's busy status to false if we own the device.

[Tanu Kaskinen]

Bug found by David Henningsson.
---
 reserve-monitor.c |   74 +++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 60 insertions(+), 14 deletions(-)

diff --git a/reserve-monitor.c b/reserve-monitor.c
index 4097a6f..39a0c77 100644
--- a/reserve-monitor.c
+++ b/reserve-monitor.c
@@ -59,6 +59,22 @@ struct rm_monitor {
 	"member='NameOwnerChanged',"		\
 	"arg0='%s'"
 
+static unsigned get_busy(
+	DBusConnection *c,
+	const char *name_owner) {
+
+	const char *un;
+
+	if (!name_owner || !*name_owner)
+		return FALSE;
+
+	if ((un = dbus_bus_get_unique_name(c)))
+		if (strcmp(name_owner, un) == 0)
+			return FALSE;
+
+	return TRUE;
+}
+
 static DBusHandlerResult filter_handler(
 	DBusConnection *c,
 	DBusMessage *s,
@@ -87,16 +103,7 @@ static DBusHandlerResult filter_handler(
 		if (strcmp(name, m->service_name) == 0) {
 			unsigned old_busy = m->busy;
 
-			m->busy = !!(new && *new);
-
-			/* If we ourselves own the device, then don't consider this 'busy' */
-			if (m->busy) {
-				const char *un;
-
-				if ((un = dbus_bus_get_unique_name(c)))
-					if (strcmp(new, un) == 0)
-						m->busy = FALSE;
-			}
+			m->busy = get_busy(c, new);
 
 			if (m->busy != old_busy && m->change_cb) {
 				m->ref++;
@@ -115,11 +122,13 @@ invalid:
 int rm_watch(
 	rm_monitor **_m,
 	DBusConnection *connection,
-	const char*device_name,
+	const char *device_name,
 	rm_change_cb_t change_cb,
 	DBusError *error)  {
 
 	rm_monitor *m = NULL;
+	DBusMessage *msg = NULL, *reply = NULL;
+	const char *name_owner;
 	int r;
 	DBusError _error;
 
@@ -178,13 +187,44 @@ int rm_watch(
 
 	m->matching = 1;
 
-	m->busy = dbus_bus_name_has_owner(m->connection, m->service_name, error);
+	if (!(msg = dbus_message_new_method_call(DBUS_SERVICE_DBUS, DBUS_PATH_DBUS, DBUS_INTERFACE_DBUS, "GetNameOwner"))) {
+		r = -ENOMEM;
+		goto fail;
+	}
 
-	if (dbus_error_is_set(error)) {
-		r = -EIO;
+	if (!dbus_message_append_args(msg, DBUS_TYPE_STRING, &m->service_name, DBUS_TYPE_INVALID)) {
+		r = -ENOMEM;
 		goto fail;
 	}
 
+	reply = dbus_connection_send_with_reply_and_block(m->connection, msg, DBUS_TIMEOUT_USE_DEFAULT, error);
+	dbus_message_unref(msg);
+	msg = NULL;
+
+	if (reply) {
+		if (!dbus_message_get_args(reply, error, DBUS_TYPE_STRING, &name_owner, DBUS_TYPE_INVALID)) {
+			r = -EIO;
+			goto fail;
+		}
+	} else {
+		if (dbus_error_has_name(error, "org.freedesktop.DBus.Error.NameHasNoOwner")) {
+			dbus_error_free(error);
+			name_owner = NULL;
+		} else {
+			r = -EIO;
+			goto fail;
+		}
+	}
+
+	m->busy = get_busy(m->connection, name_owner);
+
+	/* The reply can't be unreffed earlier, because name_owner points
+	 * inside the message. */
+	if (reply) {
+		dbus_message_unref(reply);
+		reply = NULL;
+	}
+
 	*_m = m;
 	return 0;
 
@@ -192,6 +232,12 @@ fail:
 	if (&_error == error)
 		dbus_error_free(&_error);
 
+	if (msg)
+		dbus_message_unref(msg);
+
+	if (reply)
+		dbus_message_unref(reply);
+
 	if (m)
 		rm_release(m);
 
-- 
1.7.10.4