[Blazebit#1805] Add logic to EntityViewManager and ProxyFactory to ma…

…intain evm references in proxies
Mobe91 · Oct 1, 2023 · 72a12e4 · 72a12e4
1 parent a9b1b6e
commit 72a12e4
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Showing 9 changed files with 144 additions and 12 deletions.
diff --git a/documentation/src/main/asciidoc/entity-view/manual/en_US/getting_started.adoc b/documentation/src/main/asciidoc/entity-view/manual/en_US/getting_started.adoc
@@ -323,6 +323,11 @@ public class EntityViewManagerProducer {
         evm = config.createEntityViewManager(criteriaBuilderFactory);
     }
 
+    @PreDestroy
+    public void closeEvm() {
+        evm.close();
+    }
+
     @Produces
     @ApplicationScoped
     public EntityViewManager createEntityViewManager() {
@@ -377,6 +382,11 @@ public class EntityViewManagerProducer {
         evm = config.createEntityViewManager(criteriaBuilderFactory);
     }
 
+    @PreDestroy
+    public void closeEvm() {
+        evm.close();
+    }
+
     @Produces
     @ApplicationScoped
     public EntityViewManager createEntityViewManager() {

diff --git a/entity-view/api/src/main/java/com/blazebit/persistence/view/EntityViewManager.java b/entity-view/api/src/main/java/com/blazebit/persistence/view/EntityViewManager.java
@@ -28,6 +28,14 @@
 
 /**
  * An interface that gives access to the metamodel and object builders.
+ * <p>
+ * There are currently limitations when it comes to using multiple instances of {@link EntityViewManager}
+ * simultaneously in an application. Specifically, multiple instances of {@link EntityViewManager} running within
+ * in the same class loader may not share entity view types. This is because the {@link EntityViewManager}
+ * dynamically creates proxy classes for entity view types and injects static self-references into these proxies.
+ * Another {@link EntityViewManager} creating a proxy for the same entity view type may find that the proxy class
+ * already exists within the class loader in which case it will overwrite the static self-references to point to
+ * itself leading to undefined behavior in the other {@link EntityViewManager}.
  *
  * @author Christian Beikov
  * @since 1.0.0
@@ -502,4 +510,12 @@ public interface EntityViewManager extends ServiceProvider {
      * @since 1.2.0
      */
     public <T, Q extends FullQueryBuilder<T, Q>> Q applySetting(EntityViewSetting<T, Q> setting, CriteriaBuilder<?> criteriaBuilder, String entityViewRoot);
+
+    /**
+     * Closes this {@link EntityViewManager} and frees resources. The behavior of any method called on an entity
+     * view manager after this method has been invoked is undefined.
+     *
+     * @since 1.6.10
+     */
+    public void close();
 }
diff --git a/...y-view/api/src/main/java/com/blazebit/persistence/view/SerializableEntityViewManager.java b/...y-view/api/src/main/java/com/blazebit/persistence/view/SerializableEntityViewManager.java
@@ -36,6 +36,7 @@ public class SerializableEntityViewManager implements EntityViewManager, Seriali
 
     public static final String EVM_FIELD_NAME = "ENTITY_VIEW_MANAGER";
     public static final String SERIALIZABLE_EVM_FIELD_NAME = "SERIALIZABLE_ENTITY_VIEW_MANAGER";
+    public static final String SERIALIZABLE_EVM_DELEGATE_FIELD_NAME = "evm";
 
     private final Class<?> entityViewClass;
     private transient volatile EntityViewManager evm;
@@ -275,4 +276,9 @@ public <T, Q extends FullQueryBuilder<T, Q>> Q applySetting(EntityViewSetting<T,
     public <T> T getService(Class<T> serviceClass) {
         return getEvm().getService(serviceClass);
     }
+
+    @Override
+    public void close() {
+        getEvm().close();
+    }
 }
diff --git a/entity-view/impl/src/main/java/com/blazebit/persistence/view/impl/EntityViewManagerImpl.java b/entity-view/impl/src/main/java/com/blazebit/persistence/view/impl/EntityViewManagerImpl.java
@@ -1450,6 +1450,11 @@ public EntityViewManager getSerializableDelegate(Class<?> entityViewClass) {
         return serializableDelegates.get(proxyFactory.getProxy(this, metamodel.managedViewOrError(entityViewClass)));
     }
 
+    @Override
+    public void close() {
+        proxyFactory.clear();
+    }
+
     /**
      * @author Christian Beikov
      * @since 1.2.0

diff --git a/entity-view/impl/src/main/java/com/blazebit/persistence/view/impl/proxy/ProxyFactory.java b/entity-view/impl/src/main/java/com/blazebit/persistence/view/impl/proxy/ProxyFactory.java
@@ -1011,6 +1011,8 @@ private <T> Class<? extends T> defineOrGetClass(Class<?> clazz, Class<?> neighbo
     }
 
     private <T> Class<? extends T> defineOrGetClass(EntityViewManager entityViewManager, boolean unsafe, Class<?> clazz, Class<?> neighbourClazz, CtClass cc) throws IOException, IllegalAccessException, NoSuchFieldException, CannotCompileException {
+        Class<? extends T> c;
+        boolean newlyDefined = false;
         try {
             // Ask the package opener to allow deep access, otherwise defining the class will fail
             if (clazz.getPackage() != null) {
@@ -1021,13 +1023,8 @@ private <T> Class<? extends T> defineOrGetClass(EntityViewManager entityViewMana
                 cc.writeFile(DEBUG_DUMP_DIRECTORY.toString());
             }
 
-            Class<? extends T> c = (Class<? extends T>) UnsafeHelper.define(cc.getName(), cc.toBytecode(), neighbourClazz);
-
-            if (entityViewManager != null) {
-                c.getField(SerializableEntityViewManager.EVM_FIELD_NAME).set(null, entityViewManager);
-            }
-
-            return c;
+            c = (Class<? extends T>) UnsafeHelper.define(cc.getName(), cc.toBytecode(), neighbourClazz);
+            newlyDefined = true;
         } catch (CannotCompileException | LinkageError ex) {
             // If there are multiple proxy factories for the same class loader
             // we could end up in defining a class multiple times, so we check if the classloader
@@ -1037,7 +1034,7 @@ private <T> Class<? extends T> defineOrGetClass(EntityViewManager entityViewMana
                     || ex.getCause() instanceof InvocationTargetException && ex.getCause().getCause() instanceof LinkageError && (error = (LinkageError) ex.getCause().getCause()) != null
                     || ex.getCause() instanceof LinkageError && (error = (LinkageError) ex.getCause()) != null) {
                 try {
-                    return (Class<? extends T>) pool.getClassLoader().loadClass(cc.getName());
+                    c = (Class<? extends T>) pool.getClassLoader().loadClass(cc.getName());
                 } catch (ClassNotFoundException cnfe) {
                     // Something we can't handle happened
                     throw error;
@@ -1049,12 +1046,33 @@ private <T> Class<? extends T> defineOrGetClass(EntityViewManager entityViewMana
             // With Java 9 it's actually the case that Javassist doesn't throw the LinkageError but instead tries to define the class differently
             // Too bad that this different path lead to a NullPointerException
             try {
-                return (Class<? extends T>) pool.getClassLoader().loadClass(cc.getName());
+                c = (Class<? extends T>) pool.getClassLoader().loadClass(cc.getName());
             } catch (ClassNotFoundException cnfe) {
                 // Something we can't handle happened
                 throw ex;
             }
         }
+        if (entityViewManager != null) {
+            updateEvmReferences(c, entityViewManager, !newlyDefined);
+        }
+        return c;
+    }
+
+    private void updateEvmReferences(Class<?> entityViewClass, EntityViewManager evm, boolean updateSerializableEvmDelegate) {
+        try {
+            entityViewClass.getField(SerializableEntityViewManager.EVM_FIELD_NAME).set(null, evm);
+            if (updateSerializableEvmDelegate) {
+                SerializableEntityViewManager serializableEvm =
+                    (SerializableEntityViewManager) entityViewClass.getField(
+                        SerializableEntityViewManager.SERIALIZABLE_EVM_FIELD_NAME).get(null);
+                Field serializableEvmDelegateField = SerializableEntityViewManager.class.getDeclaredField(
+                    SerializableEntityViewManager.SERIALIZABLE_EVM_DELEGATE_FIELD_NAME);
+                serializableEvmDelegateField.setAccessible(true);
+                serializableEvmDelegateField.set(serializableEvm, evm);
+            }
+        } catch (IllegalAccessException | NoSuchFieldException e) {
+            throw new RuntimeException(e);
+        }
     }
 
     private boolean shouldAddDefaultConstructor(boolean hasEmptyConstructor, boolean addedReferenceConstructor, CtField[] attributeFields) {
@@ -3489,4 +3507,17 @@ private String getGenericSignature(MethodAttribute<?, ?> attribute, CtField attr
 
         return sb.toString();
     }
+
+    public void clear() {
+        for (Class<?> proxyClass : proxyClasses.values()) {
+            updateEvmReferences(proxyClass, null, true);
+        }
+        proxyClasses.clear();
+        for (Class<?> unsafeProxyClass : unsafeProxyClasses.values()) {
+            updateEvmReferences(unsafeProxyClass, null, true);
+        }
+        unsafeProxyClasses.clear();
+        baseClasses.clear();
+        proxyClassesToViewClasses.clear();
+    }
 }
diff --git a/...stsuite/src/test/java/com/blazebit/persistence/view/testsuite/AbstractEntityViewTest.java b/...stsuite/src/test/java/com/blazebit/persistence/view/testsuite/AbstractEntityViewTest.java
@@ -64,7 +64,7 @@ public EntityViewManager build(EntityViewConfiguration cfg, Class<?>... classes)
         EntityViewManagerFactoryCacheKey cacheKey = new EntityViewManagerFactoryCacheKey(cbf, cfg);
         EntityViewManager evm;
         if ((evm = evmCache.get(cacheKey)) == null) {
-            evm = build0(cfg, classes);
+            evm = build0(cfg);
             evmCache.put(cacheKey, evm);
         }
         AbstractEntityViewTest.evm = evm;
@@ -100,7 +100,7 @@ public EntityViewManager build(EntityViewConfiguration cfg, Class<?>... classes)
         return evm;
     }
 
-    private EntityViewManager build0(EntityViewConfiguration cfg, Class<?>[] classes) {
+    private EntityViewManager build0(EntityViewConfiguration cfg) {
         return cfg.createEntityViewManager(cbf);
     }
 

diff --git a/...stsuite/src/test/java/com/blazebit/persistence/view/testsuite/proxy/ProxyFactoryTest.java b/...stsuite/src/test/java/com/blazebit/persistence/view/testsuite/proxy/ProxyFactoryTest.java
@@ -21,6 +21,7 @@
 import com.blazebit.persistence.view.ConfigurationProperties;
 import com.blazebit.persistence.view.EntityViewManager;
 import com.blazebit.persistence.view.EntityViews;
+import com.blazebit.persistence.view.SerializableEntityViewManager;
 import com.blazebit.persistence.view.impl.metamodel.ManagedViewTypeImplementor;
 import com.blazebit.persistence.view.impl.metamodel.MappingConstructorImpl;
 import com.blazebit.persistence.view.impl.proxy.ObjectInstantiator;
@@ -337,11 +338,64 @@ public void testProxyToStringFlatView() throws Exception {
     }
 
     @Test
-    public void testMutableProxyWithPrimitiveArray() throws Exception {
+    public void testMutableProxyWithPrimitiveArray() {
         ManagedViewType<DocumentCreateViewWithPrimitiveArray> viewType = build(entityViewConfiguration, DocumentCreateViewWithPrimitiveArray.class).getMetamodel().managedView(DocumentCreateViewWithPrimitiveArray.class);
         proxyFactory.getProxy(evm, (ManagedViewTypeImplementor<DocumentCreateViewWithPrimitiveArray>) viewType);
     }
 
+    @Test
+    public void close() throws NoSuchFieldException, IllegalAccessException {
+        // Given
+        EntityViewManager evm = build(entityViewConfiguration, DocumentCreateViewWithPrimitiveArray.class,
+            DocumentInterfaceView.class);
+        ManagedViewType<DocumentCreateViewWithPrimitiveArray> documentCreateViewWithPrimitiveArrayType = evm.getMetamodel()
+            .managedView(DocumentCreateViewWithPrimitiveArray.class);
+        ManagedViewType<DocumentInterfaceView> documentInterfaceViewType = evm.getMetamodel()
+            .managedView(DocumentInterfaceView.class);
+        Class<? extends DocumentCreateViewWithPrimitiveArray> documentCreateViewWithPrimitiveArrayProxyClass = proxyFactory.getProxy(
+            AbstractEntityViewTest.evm, (ManagedViewTypeImplementor<DocumentCreateViewWithPrimitiveArray>) documentCreateViewWithPrimitiveArrayType);
+        Class<? extends DocumentInterfaceView> documentInterfaceViewProxyClass = proxyFactory.getProxy(
+            AbstractEntityViewTest.evm, (ManagedViewTypeImplementor<DocumentInterfaceView>) documentInterfaceViewType);
+
+        // When
+        proxyFactory.clear();
+
+        // Then
+        assertProxyEvmReferencesNull(documentCreateViewWithPrimitiveArrayProxyClass);
+        assertProxyEvmReferencesNull(documentInterfaceViewProxyClass);
+        Map<Class<?>, Class<?>> baseClasses = getDeclaredFieldValue(proxyFactory, "unsafeProxyClasses", Map.class);
+        assertTrue(baseClasses.isEmpty());
+        Map<Class<?>, Class<?>> proxyClasses = getDeclaredFieldValue(proxyFactory, "unsafeProxyClasses", Map.class);
+        assertTrue(proxyClasses.isEmpty());
+        Map<Class<?>, Class<?>> unsafeProxyClasses = getDeclaredFieldValue(proxyFactory, "unsafeProxyClasses", Map.class);
+        assertTrue(unsafeProxyClasses.isEmpty());
+        Map<Class<?>, Class<?>> proxyClassesToViewClasses = getDeclaredFieldValue(proxyFactory, "proxyClassesToViewClasses", Map.class);
+        assertTrue(proxyClassesToViewClasses.isEmpty());
+    }
+
+    private void assertProxyEvmReferencesNull(Class<?> proxy) throws NoSuchFieldException, IllegalAccessException {
+        EntityViewManager proxyEvm = (EntityViewManager) proxy.getField(SerializableEntityViewManager.EVM_FIELD_NAME).get(null);
+        SerializableEntityViewManager serializableEvm =
+            (SerializableEntityViewManager) proxy.getField(
+                SerializableEntityViewManager.SERIALIZABLE_EVM_FIELD_NAME).get(null);
+        Field serializableEvmDelegateField = SerializableEntityViewManager.class.getDeclaredField(
+            SerializableEntityViewManager.SERIALIZABLE_EVM_DELEGATE_FIELD_NAME);
+        serializableEvmDelegateField.setAccessible(true);
+        EntityViewManager serializableEvmDelegate = (EntityViewManager) serializableEvmDelegateField.get(serializableEvm);
+        assertNull(proxyEvm);
+        assertNull(serializableEvmDelegate);
+    }
+
+    private <T> T getDeclaredFieldValue(Object obj, String fieldName, Class<T> resultType) {
+        try {
+            Field field = obj.getClass().getDeclaredField(fieldName);
+            field.setAccessible(true);
+            return (T) field.get(obj);
+        } catch (NoSuchFieldException | IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     private void assertAttribute(Class<?> proxyClass, String fieldName, int modifiers, Class<?> type, Class<?>... typeArguments) throws Exception {
         assertField(proxyClass, fieldName, modifiers, type, typeArguments);
         assertGetter(proxyClass, fieldName, type, typeArguments);

diff --git a/.../java/com/blazebit/persistence/integration/jaxrs/jackson/EntityViewMessageBodyReader.java b/.../java/com/blazebit/persistence/integration/jaxrs/jackson/EntityViewMessageBodyReader.java
@@ -542,5 +542,10 @@ public <T, Q extends FullQueryBuilder<T, Q>> Q applySetting(EntityViewSetting<T,
         public <T> T getService(Class<T> serviceClass) {
             return entityViewManager.get().getService(serviceClass);
         }
+
+        @Override
+        public void close() {
+            entityViewManager.get().close();
+        }
     }
 }
diff --git a/...in/java/com/blazebit/persistence/integration/jaxrs/jsonb/EntityViewMessageBodyReader.java b/...in/java/com/blazebit/persistence/integration/jaxrs/jsonb/EntityViewMessageBodyReader.java
@@ -539,5 +539,10 @@ public <T, Q extends FullQueryBuilder<T, Q>> Q applySetting(EntityViewSetting<T,
         public <T> T getService(Class<T> serviceClass) {
             return entityViewManager.get().getService(serviceClass);
         }
+
+        @Override
+        public void close() {
+            entityViewManager.get().close();
+        }
     }
 }