public function wasReadOnlyError();
/**
- * Wait for the slave to catch up to a given master position.
+ * Wait for the slave to catch up to a given master position
*
* @param DBMasterPos $pos
- * @param int $timeout The maximum number of seconds to wait for
- * synchronisation
- * @return int Zero if the slave was past that position already,
+ * @param int $timeout The maximum number of seconds to wait for synchronisation
+ * @return int|null Zero if the slave was past that position already,
* greater than zero if we waited for some period of time, less than
- * zero if we timed out.
+ * zero if it timed out, and null on error
*/
public function masterPosWait( DBMasterPos $pos, $timeout );