file_add_class( VipsForeignClass *class, GSList **files )
{
	/* Append so we don't reverse the list of files. Sort will not reorder
	 * items of equal priority. 
	 */
	*files = g_slist_append( *files, class );

	return( NULL );
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.