If udpsrc is used with external socket (passed via socket property), this socket is unreffed upon element disposal, despite ownership being not transferred.

Sample code:


public static int main(string[] argv) {
	Gst.init(ref argv);

	var socket = new Socket(SocketFamily.IPV4, SocketType.DATAGRAM, SocketProtocol.UDP);
	socket.bind(new InetSocketAddress(new InetAddress.any(SocketFamily.IPV4), 0), true);

	var pipeline = new Gst.Pipeline("pipeline");

	dynamic Gst.Element source = Gst.ElementFactory.make("udpsrc", "source");
	source.socket = socket;

	dynamic Gst.Element sink = Gst.ElementFactory.make("fakesink", "sink");

	pipeline.add(source);
	pipeline.add(sink);

	source.link(sink);

	pipeline.set_state(Gst.State.PLAYING);
	pipeline.set_state(Gst.State.NULL);
	pipeline.set_state(Gst.State.PLAYING);


	return 0;
}

Compile with valac --pkg gstreamer-1.0 --pkg gio-2.0 udpsrc.vala


Produces:

(udpsrc:42922): GLib-GIO-CRITICAL **: g_inet_socket_address_get_address: assertion 'G_IS_INET_SOCKET_ADDRESS (address)' failed

(udpsrc:42922): GLib-GIO-CRITICAL **: g_inet_address_get_is_multicast: assertion 'G_IS_INET_ADDRESS (address)' failed

(udpsrc:42922): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed


If the intention was to transfer ownership of socket into element, it is not documented behaviour. 

But IMO it should not behave like this - you may want to ensure that socket is constantly bound across state changes (e.g. so no other process will intercept it).