wp_scheduled_delete() WordPress Function

function wp_scheduled_delete() {
	global $wpdb;

	$delete_timestamp = time() - ( DAY_IN_SECONDS * EMPTY_TRASH_DAYS );

	$posts_to_delete = $wpdb->get_results( $wpdb->prepare( "SELECT post_id FROM $wpdb->postmeta WHERE meta_key = '_wp_trash_meta_time' AND meta_value < %d", $delete_timestamp ), ARRAY_A );

	foreach ( (array) $posts_to_delete as $post ) {
		$post_id = (int) $post['post_id'];
		if ( ! $post_id ) {
			continue;
		}

		$del_post = get_post( $post_id );

		if ( ! $del_post || 'trash' !== $del_post->post_status ) {
			delete_post_meta( $post_id, '_wp_trash_meta_status' );
			delete_post_meta( $post_id, '_wp_trash_meta_time' );
		} else {
			wp_delete_post( $post_id );
		}
	}

	$comments_to_delete = $wpdb->get_results( $wpdb->prepare( "SELECT comment_id FROM $wpdb->commentmeta WHERE meta_key = '_wp_trash_meta_time' AND meta_value < %d", $delete_timestamp ), ARRAY_A );

	foreach ( (array) $comments_to_delete as $comment ) {
		$comment_id = (int) $comment['comment_id'];
		if ( ! $comment_id ) {
			continue;
		}

		$del_comment = get_comment( $comment_id );

		if ( ! $del_comment || 'trash' !== $del_comment->comment_approved ) {
			delete_comment_meta( $comment_id, '_wp_trash_meta_time' );
			delete_comment_meta( $comment_id, '_wp_trash_meta_status' );
		} else {
			wp_delete_comment( $del_comment );
		}
	}
}