Consistent FactoryBean cache visibility in concurrent creation scenarios

Issue: SPR-16625
Issue: SPR-16627

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractAutowireCapableBeanFactory.java

@@ -927,12 +927,16 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 			if (bw != null) {
 				return (FactoryBean<?>) bw.getWrappedInstance();
 			}
+			Object beanInstance = getSingleton(beanName, false);
+			if (beanInstance instanceof FactoryBean) {
+				return (FactoryBean<?>) beanInstance;
+			}
 			if (isSingletonCurrentlyInCreation(beanName) ||
 					(mbd.getFactoryBeanName() != null && isSingletonCurrentlyInCreation(mbd.getFactoryBeanName()))) {
 				return null;
 			}
 
-			Object instance = null;
+			Object instance;
 			try {
 				// Mark this bean as currently in creation, even if just partially.
 				beforeSingletonCreation(beanName);
@@ -1845,8 +1849,21 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	 */
 	@Override
 	protected void removeSingleton(String beanName) {
-		super.removeSingleton(beanName);
-		this.factoryBeanInstanceCache.remove(beanName);
+		synchronized (getSingletonMutex()) {
+			super.removeSingleton(beanName);
+			this.factoryBeanInstanceCache.remove(beanName);
+		}
+	}
+
+	/**
+	 * Overridden to clear FactoryBean instance cache as well.
+	 */
+	@Override
+	protected void clearSingletonCache() {
+		synchronized (getSingletonMutex()) {
+			super.clearSingletonCache();
+			this.factoryBeanInstanceCache.clear();
+		}
 	}
 
 

spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultSingletonBeanRegistry.java

@@ -392,11 +392,7 @@ public class DefaultSingletonBeanRegistry extends SimpleAliasRegistry implements
 
 		// No entry yet -> fully synchronized manipulation of the containedBeans Set
 		synchronized (this.containedBeanMap) {
-			containedBeans = this.containedBeanMap.get(containingBeanName);
-			if (containedBeans == null) {
-				containedBeans = new LinkedHashSet<>(8);
-				this.containedBeanMap.put(containingBeanName, containedBeans);
-			}
+			containedBeans = this.containedBeanMap.computeIfAbsent(containingBeanName, k -> new LinkedHashSet<>(8));
 			containedBeans.add(containedBeanName);
 		}
 		registerDependentBean(containedBeanName, containingBeanName);
@@ -418,19 +414,12 @@ public class DefaultSingletonBeanRegistry extends SimpleAliasRegistry implements
 
 		// No entry yet -> fully synchronized manipulation of the dependentBeans Set
 		synchronized (this.dependentBeanMap) {
-			dependentBeans = this.dependentBeanMap.get(canonicalName);
-			if (dependentBeans == null) {
-				dependentBeans = new LinkedHashSet<>(8);
-				this.dependentBeanMap.put(canonicalName, dependentBeans);
-			}
+			dependentBeans = this.dependentBeanMap.computeIfAbsent(canonicalName, k -> new LinkedHashSet<>(8));
 			dependentBeans.add(dependentBeanName);
 		}
 		synchronized (this.dependenciesForBeanMap) {
-			Set<String> dependenciesForBean = this.dependenciesForBeanMap.get(dependentBeanName);
-			if (dependenciesForBean == null) {
-				dependenciesForBean = new LinkedHashSet<>(8);
-				this.dependenciesForBeanMap.put(dependentBeanName, dependenciesForBean);
-			}
+			Set<String> dependenciesForBean =
+					this.dependenciesForBeanMap.computeIfAbsent(dependentBeanName, k -> new LinkedHashSet<>(8));
 			dependenciesForBean.add(canonicalName);
 		}
 	}
@@ -525,6 +514,14 @@ public class DefaultSingletonBeanRegistry extends SimpleAliasRegistry implements
 		this.dependentBeanMap.clear();
 		this.dependenciesForBeanMap.clear();
 
+		clearSingletonCache();
+	}
+
+	/**
+	 * Clear all cached singleton instances in this registry.
+	 * @since 4.3.15
+	 */
+	protected void clearSingletonCache() {
 		synchronized (this.singletonObjects) {
 			this.singletonObjects.clear();
 			this.singletonFactories.clear();

spring-beans/src/main/java/org/springframework/beans/factory/support/FactoryBeanRegistrySupport.java

 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -214,17 +214,21 @@ public abstract class FactoryBeanRegistrySupport extends DefaultSingletonBeanReg
 	 */
 	@Override
 	protected void removeSingleton(String beanName) {
-		super.removeSingleton(beanName);
-		this.factoryBeanObjectCache.remove(beanName);
+		synchronized (getSingletonMutex()) {
+			super.removeSingleton(beanName);
+			this.factoryBeanObjectCache.remove(beanName);
+		}
 	}
 
 	/**
 	 * Overridden to clear the FactoryBean object cache as well.
 	 */
 	@Override
-	public void destroySingletons() {
-		super.destroySingletons();
-		this.factoryBeanObjectCache.clear();
+	protected void clearSingletonCache() {
+		synchronized (getSingletonMutex()) {
+			super.clearSingletonCache();
+			this.factoryBeanObjectCache.clear();
+		}
 	}
 
 	/**