Details
Description
When setting a pessimistic lock on an entity (e.g. a row lock) and retreiving an entity from the database, Doctrine returns the entity from cache if it has any. When updating a counter on an entity for example, it is important the row is locked, retreived, updated and then unlocked to guarantee the counter keeps in sync. Using $em->clear(); before $em->find(); is a work-around for this problem, but as requested by Benjamin Eberlei on the google groups thread (https://groups.google.com/forum/?fromgroups#!topic/doctrine-user/N8Xop2-XbTY) this bugreport is made to fix this without the need of clear().
In the next example, if the entity is previously retreived already, find() returns that version instead of retreiving the current version from the database after the rowlock is set. When $em->clear(); can be used to work-around the problem
// $em instanceof EntityManager //$em->clear(); // Uncommenting this fixed the problem $em->getConnection()->beginTransaction(); try { $entity = $em->find('Entity', $id, LockMode::PESSIMISTIC_WRITE); /* Update some fields, for example, decrease a counter */ $entity->setCounter($entity->getCounter() - 1); $em->persist($entity); $em->flush(); $em->getConnection()->commit(); } catch ( \Exception $ex ) { $em->getConnection()->rollback(); }
Any update or ETA on this one? The work-around is still in my production code and I would like to get it out to get it cleaned-up a bit.