LazySingletonAspectInstanceFactoryDecorator uses shared singleton mutex

Issue: SPR-14241

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/BeanFactoryAspectInstanceFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.OrderUtils;
+import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
 /**
@@ -66,6 +67,8 @@ public class BeanFactoryAspectInstanceFactory implements MetadataAwareAspectInst
 	 * @param type the type that should be introspected by AspectJ
 	 */
 	public BeanFactoryAspectInstanceFactory(BeanFactory beanFactory, String name, Class<?> type) {
+		Assert.notNull(beanFactory, "BeanFactory must not be null");
+		Assert.notNull(name, "Bean name must not be null");
 		this.beanFactory = beanFactory;
 		this.name = name;
 		this.aspectMetadata = new AspectMetadata(type, name);
@@ -79,12 +82,9 @@ public class BeanFactoryAspectInstanceFactory implements MetadataAwareAspectInst
 
 	@Override
 	public ClassLoader getAspectClassLoader() {
-		if (this.beanFactory instanceof ConfigurableBeanFactory) {
-			return ((ConfigurableBeanFactory) this.beanFactory).getBeanClassLoader();
-		}
-		else {
-			return ClassUtils.getDefaultClassLoader();
-		}
+		return (this.beanFactory instanceof ConfigurableBeanFactory ?
+				((ConfigurableBeanFactory) this.beanFactory).getBeanClassLoader() :
+				ClassUtils.getDefaultClassLoader());
 	}
 
 	@Override
@@ -92,6 +92,11 @@ public class BeanFactoryAspectInstanceFactory implements MetadataAwareAspectInst
 		return this.aspectMetadata;
 	}
 
+	public Object getAspectCreationMutex() {
+		return (this.beanFactory instanceof ConfigurableBeanFactory ?
+				((ConfigurableBeanFactory) this.beanFactory).getSingletonMutex() : this);
+	}
+
 	/**
 	 * Determine the order for this factory's target aspect, either
 	 * an instance-specific order expressed through implementing the

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/LazySingletonAspectInstanceFactoryDecorator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -43,9 +43,13 @@ public class LazySingletonAspectInstanceFactoryDecorator implements MetadataAwar
 
 
 	@Override
-	public synchronized Object getAspectInstance() {
+	public Object getAspectInstance() {
 		if (this.materialized == null) {
-			synchronized (this) {
+			Object mutex = this;
+			if (this.maaif instanceof BeanFactoryAspectInstanceFactory) {
+				mutex = ((BeanFactoryAspectInstanceFactory) this.maaif).getAspectCreationMutex();
+			}
+			synchronized (mutex) {
 				if (this.materialized == null) {
 					this.materialized = this.maaif.getAspectInstance();
 				}