BeanFactoryAdvisorRetrievalHelper avoids synchronization for name cache

Issue: SPR-16570

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/BeanFactoryAdvisorRetrievalHelper.java

@@ -45,7 +45,7 @@ public class BeanFactoryAdvisorRetrievalHelper {
 	private final ConfigurableListableBeanFactory beanFactory;
 
 	@Nullable
-	private String[] cachedAdvisorBeanNames;
+	private volatile String[] cachedAdvisorBeanNames;
 
 
 	/**
@@ -66,9 +66,7 @@ public class BeanFactoryAdvisorRetrievalHelper {
 	 */
 	public List<Advisor> findAdvisorBeans() {
 		// Determine list of advisor bean names, if not cached already.
-		String[] advisorNames = null;
+		String[] advisorNames = this.cachedAdvisorBeanNames;
-		synchronized (this) {
-			advisorNames = this.cachedAdvisorBeanNames;
 		if (advisorNames == null) {
 			// Do not initialize FactoryBeans here: We need to leave all regular beans
 			// uninitialized to let the auto-proxy creator apply to them!
@@ -76,7 +74,6 @@ public class BeanFactoryAdvisorRetrievalHelper {
 					this.beanFactory, Advisor.class, true, false);
 			this.cachedAdvisorBeanNames = advisorNames;
 		}
-		}
 		if (advisorNames.length == 0) {
 			return new ArrayList<>();
 		}