Take advantage of AnnotationRegistry::registerUniqueLoader

This method will only add 'class_exists' as an autoloader if it has not
already been added. This helps alleviate a performance issue when the
same loader is added many times in tests.

Author: jrjohnson

DependencyInjection/FrameworkExtension.php

@@ -12,6 +12,7 @@
 namespace Symfony\Bundle\FrameworkBundle\DependencyInjection;
 
 use Doctrine\Common\Annotations\Reader;
+use Doctrine\Common\Annotations\AnnotationRegistry;
 use Symfony\Bridge\Monolog\Processor\DebugProcessor;
 use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Bundle\FrameworkBundle\Controller\Controller;
@@ -1087,6 +1088,11 @@ private function registerAnnotationsConfiguration(array $config, ContainerBuilde
 
         $loader->load('annotations.xml');
 
+        if (!method_exists(AnnotationRegistry::class, 'registerUniqueLoader')) {
+            $container->getDefinition('annotations.dummy_registry')
+                ->setMethodCalls(array(array('registerLoader', array('class_exists'))));
+        }
+
         if ('none' !== $config['cache']) {
             $cacheService = $config['cache'];
 

Resources/config/annotations.xml

@@ -10,14 +10,14 @@
         <service id="annotations.reader" class="Doctrine\Common\Annotations\AnnotationReader">
             <call method="addGlobalIgnoredName">
                 <argument>required</argument>
-                <argument type="service">
-                    <!-- dummy arg to register class_exists as annotation loader only when required -->
-                    <service class="Doctrine\Common\Annotations\AnnotationRegistry">
-                        <call method="registerLoader">
-                            <argument>class_exists</argument>
-                        </call>
-                    </service>
-                </argument>
+                <!-- dummy arg to register class_exists as annotation loader only when required -->
+                <argument type="service" id="annotations.dummy_registry" />
+            </call>
+        </service>
+
+        <service id="annotations.dummy_registry" class="Doctrine\Common\Annotations\AnnotationRegistry">
+            <call method="registerUniqueLoader">
+                <argument>class_exists</argument>
             </call>
         </service>