Mitigate problems with EntityManager::flush() reentrance since 2.16.0 (Take 2)

docs/en/reference/events.rst

@@ -705,13 +705,21 @@ not directly mapped by Doctrine.
 -  The ``postUpdate`` event occurs after the database
    update operations to entity data. It is not called for a DQL
    ``UPDATE`` statement.
--  The ``postPersist`` event occurs for an entity after
-   the entity has been made persistent. It will be invoked after the
-   database insert operation for that entity. A generated primary key value for
-   the entity will be available in the postPersist event.
+-  The ``postPersist`` event occurs for an entity after the entity has
+   been made persistent. It will be invoked after all database insert
+   operations for new entities have been performed. Generated primary
+   key values will be available for all entities at the time this
+   event is triggered.
 -  The ``postRemove`` event occurs for an entity after the
-   entity has been deleted. It will be invoked after the database
-   delete operations. It is not called for a DQL ``DELETE`` statement.
+   entity has been deleted. It will be invoked after all database
+   delete operations for entity rows have been executed. This event is
+   not called for a DQL ``DELETE`` statement.
+
+.. note::
+
+    At the time ``postPersist`` is called, there may still be collection and/or
+    "extra" updates pending. The database may not yet be completely in
+    sync with the entity states in memory, not even for the new entities.
 
 .. warning::
 
@@ -720,6 +728,19 @@ not directly mapped by Doctrine.
     cascade remove relations. In this case, you should load yourself the proxy in
     the associated ``pre*`` event.
 
+.. warning::
+
+    Making changes to entities and calling ``EntityManager::flush()`` from within
+    ``post*`` event handlers is strongly discouraged, and might be deprecated and
+    eventually prevented in the future.
+
+    The reason is that it causes re-entrance into ``UnitOfWork::commit()`` while a commit
+    is currently being processed. The ``UnitOfWork`` was never designed to support this,
+    and its behavior in this situation is not covered by any tests.
+
+    This may lead to entity or collection updates being missed, applied only in parts and
+    changes being lost at the end of the commit phase.
+
 .. _reference-events-post-load:
 
 postLoad

lib/Doctrine/ORM/UnitOfWork.php

@@ -1164,13 +1164,13 @@ public function recomputeSingleEntityChangeSet(ClassMetadata $class, $entity)
      */
     private function executeInserts(): void
     {
-        $entities = $this->computeInsertExecutionOrder();
+        $entities         = $this->computeInsertExecutionOrder();
+        $eventsToDispatch = [];
 
         foreach ($entities as $entity) {
             $oid       = spl_object_id($entity);
             $class     = $this->em->getClassMetadata(get_class($entity));
             $persister = $this->getEntityPersister($class->name);
-            $invoke    = $this->listenersInvoker->getSubscribedSystems($class, Events::postPersist);
 
             $persister->addInsert($entity);
 
@@ -1197,10 +1197,24 @@ private function executeInserts(): void
                 $this->addToEntityIdentifiersAndEntityMap($class, $oid, $entity);
             }
 
+            $invoke = $this->listenersInvoker->getSubscribedSystems($class, Events::postPersist);
+
             if ($invoke !== ListenersInvoker::INVOKE_NONE) {
-                $this->listenersInvoker->invoke($class, Events::postPersist, $entity, new PostPersistEventArgs($entity, $this->em), $invoke);
+                $eventsToDispatch[] = ['class' => $class, 'entity' => $entity, 'invoke' => $invoke];
             }
         }
+
+        // Defer dispatching `postPersist` events to until all entities have been inserted and post-insert
+        // IDs have been assigned.
+        foreach ($eventsToDispatch as $event) {
+            $this->listenersInvoker->invoke(
+                $event['class'],
+                Events::postPersist,
+                $event['entity'],
+                new PostPersistEventArgs($event['entity'], $this->em),
+                $event['invoke']
+            );
+        }
     }
 
     /**
@@ -1270,7 +1284,8 @@ private function executeUpdates(): void
      */
     private function executeDeletions(): void
     {
-        $entities = $this->computeDeleteExecutionOrder();
+        $entities         = $this->computeDeleteExecutionOrder();
+        $eventsToDispatch = [];
 
         foreach ($entities as $entity) {
             $oid       = spl_object_id($entity);
@@ -1295,9 +1310,20 @@ private function executeDeletions(): void
             }
 
             if ($invoke !== ListenersInvoker::INVOKE_NONE) {
-                $this->listenersInvoker->invoke($class, Events::postRemove, $entity, new PostRemoveEventArgs($entity, $this->em), $invoke);
+                $eventsToDispatch[] = ['class' => $class, 'entity' => $entity, 'invoke' => $invoke];
             }
         }
+
+        // Defer dispatching `postRemove` events to until all entities have been removed.
+        foreach ($eventsToDispatch as $event) {
+            $this->listenersInvoker->invoke(
+                $event['class'],
+                Events::postRemove,
+                $event['entity'],
+                new PostRemoveEventArgs($event['entity'], $this->em),
+                $event['invoke']
+            );
+        }
     }
 
     /** @return list<object> */

tests/Doctrine/Tests/ORM/Functional/EntityListenersTest.php

@@ -4,12 +4,18 @@
 
 namespace Doctrine\Tests\ORM\Functional;
 
+use Doctrine\ORM\Event\PostPersistEventArgs;
+use Doctrine\ORM\Event\PostRemoveEventArgs;
 use Doctrine\ORM\Event\PreFlushEventArgs;
 use Doctrine\ORM\Event\PreUpdateEventArgs;
+use Doctrine\ORM\Events;
+use Doctrine\ORM\UnitOfWork;
 use Doctrine\Persistence\Event\LifecycleEventArgs;
 use Doctrine\Tests\Models\Company\CompanyContractListener;
 use Doctrine\Tests\Models\Company\CompanyFixContract;
+use Doctrine\Tests\Models\Company\CompanyPerson;
 use Doctrine\Tests\OrmFunctionalTestCase;
+use PHPUnit\Framework\Assert;
 
 /** @group DDC-1955 */
 class EntityListenersTest extends OrmFunctionalTestCase
@@ -96,6 +102,45 @@ public function testPostPersistListeners(): void
         self::assertInstanceOf(LifecycleEventArgs::class, $this->listener->postPersistCalls[0][1]);
     }
 
+    public function testPostPersistCalledAfterAllInsertsHaveBeenPerformedAndIdsHaveBeenAssigned(): void
+    {
+        $object1 = new CompanyFixContract();
+        $object1->setFixPrice(2000);
+
+        $object2 = new CompanyPerson();
+        $object2->setName('J. Doe');
+
+        $this->_em->persist($object1);
+        $this->_em->persist($object2);
+
+        $listener = new class ([$object1, $object2]) {
+            /** @var array<object> */
+            private $trackedObjects;
+
+            /** @var int */
+            public $invocationCount = 0;
+
+            public function __construct(array $trackedObjects)
+            {
+                $this->trackedObjects = $trackedObjects;
+            }
+
+            public function postPersist(PostPersistEventArgs $args): void
+            {
+                foreach ($this->trackedObjects as $object) {
+                    Assert::assertNotNull($object->getId());
+                }
+
+                ++$this->invocationCount;
+            }
+        };
+
+        $this->_em->getEventManager()->addEventListener(Events::postPersist, $listener);
+        $this->_em->flush();
+
+        self::assertSame(2, $listener->invocationCount);
+    }
+
     public function testPreUpdateListeners(): void
     {
         $fix = new CompanyFixContract();
@@ -175,4 +220,50 @@ public function testPostRemoveListeners(): void
         self::assertInstanceOf(CompanyFixContract::class, $this->listener->postRemoveCalls[0][0]);
         self::assertInstanceOf(LifecycleEventArgs::class, $this->listener->postRemoveCalls[0][1]);
     }
+
+    public function testPostRemoveCalledAfterAllRemovalsHaveBeenPerformed(): void
+    {
+        $object1 = new CompanyFixContract();
+        $object1->setFixPrice(2000);
+
+        $object2 = new CompanyPerson();
+        $object2->setName('J. Doe');
+
+        $this->_em->persist($object1);
+        $this->_em->persist($object2);
+        $this->_em->flush();
+
+        $listener = new class ($this->_em->getUnitOfWork(), [$object1, $object2]) {
+            /** @var UnitOfWork */
+            private $uow;
+
+            /** @var array<object> */
+            private $trackedObjects;
+
+            /** @var int */
+            public $invocationCount = 0;
+
+            public function __construct(UnitOfWork $uow, array $trackedObjects)
+            {
+                $this->uow            = $uow;
+                $this->trackedObjects = $trackedObjects;
+            }
+
+            public function postRemove(PostRemoveEventArgs $args): void
+            {
+                foreach ($this->trackedObjects as $object) {
+                    Assert::assertFalse($this->uow->isInIdentityMap($object));
+                }
+
+                ++$this->invocationCount;
+            }
+        };
+
+        $this->_em->getEventManager()->addEventListener(Events::postRemove, $listener);
+        $this->_em->remove($object1);
+        $this->_em->remove($object2);
+        $this->_em->flush();
+
+        self::assertSame(2, $listener->invocationCount);
+    }
 }

tests/Doctrine/Tests/ORM/Functional/Ticket/GH10869Test.php

@@ -0,0 +1,76 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\ORM\Functional\Ticket;
+
+use Doctrine\ORM\Event\PostPersistEventArgs;
+use Doctrine\ORM\Events;
+use Doctrine\ORM\Mapping as ORM;
+use Doctrine\Tests\OrmFunctionalTestCase;
+
+class GH10869Test extends OrmFunctionalTestCase
+{
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->setUpEntitySchema([
+            GH10869Entity::class,
+        ]);
+    }
+
+    public function testPostPersistListenerUpdatingObjectFieldWhileOtherInsertPending(): void
+    {
+        $entity1 = new GH10869Entity();
+        $this->_em->persist($entity1);
+
+        $entity2 = new GH10869Entity();
+        $this->_em->persist($entity2);
+
+        $this->_em->getEventManager()->addEventListener(Events::postPersist, new class {
+            public function postPersist(PostPersistEventArgs $args): void
+            {
+                $object = $args->getObject();
+
+                $objectManager = $args->getObjectManager();
+                $object->field = 'test ' . $object->id;
+                $objectManager->flush();
+            }
+        });
+
+        $this->_em->flush();
+        $this->_em->clear();
+
+        self::assertSame('test ' . $entity1->id, $entity1->field);
+        self::assertSame('test ' . $entity2->id, $entity2->field);
+
+        $entity1Reloaded = $this->_em->find(GH10869Entity::class, $entity1->id);
+        self::assertSame($entity1->field, $entity1Reloaded->field);
+
+        $entity2Reloaded = $this->_em->find(GH10869Entity::class, $entity2->id);
+        self::assertSame($entity2->field, $entity2Reloaded->field);
+    }
+}
+
+/**
+ * @ORM\Entity
+ */
+class GH10869Entity
+{
+    /**
+     * @ORM\Id
+     * @ORM\GeneratedValue
+     * @ORM\Column(type="integer")
+     *
+     * @var ?int
+     */
+    public $id;
+
+    /**
+     * @ORM\Column(type="text", nullable=true)
+     *
+     * @var ?string
+     */
+    public $field;
+}