Change "synchronized" to reentrant lock for virtual-threads

Fix checkstyles before merge

Code cleanup

Double-Checked Locking Optimization was used to avoid unnecessary locking overhead.

core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binding/BindableProxyFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2022 the original author or authors.
+ * Copyright 2015-2024 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.
@@ -19,6 +19,7 @@ package org.springframework.cloud.stream.binding;
 import java.lang.reflect.Method;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.aopalliance.intercept.MethodInterceptor;
 import org.aopalliance.intercept.MethodInvocation;
@@ -43,6 +44,7 @@ import org.springframework.util.Assert;
  * @author Ilayaperumal Gopinathan
  * @author Oleg Zhurakousky
  * @author Soby Chacko
+ * @author Omer Celik
  */
 public class BindableProxyFactory extends AbstractBindableProxyFactory
 		implements MethodInterceptor, FactoryBean<Object>, InitializingBean, BeanFactoryAware {
@@ -55,21 +57,25 @@ public class BindableProxyFactory extends AbstractBindableProxyFactory
 
 	protected BeanFactory beanFactory;
 
+	private final ReentrantLock lock = new ReentrantLock();
+
 	public BindableProxyFactory(Class<?> type) {
 		super(type);
 		this.type = type;
 	}
 
 	@Override
-	public synchronized Object invoke(MethodInvocation invocation) {
-		Method method = invocation.getMethod();
+	public Object invoke(MethodInvocation invocation) {
+		try {
+			this.lock.lock();
+			Method method = invocation.getMethod();
 
-		// try to use cached target
-		Object boundTarget = this.targetCache.get(method);
-		if (boundTarget != null) {
-			return boundTarget;
+			// try to use cached target
+			return this.targetCache.get(method);
+		}
+		finally {
+			this.lock.unlock();
 		}
-		return null;
 	}
 
 	public void replaceInputChannel(String originalChannelName, String newChannelName, SubscribableChannel messageChannel) {
@@ -97,11 +103,22 @@ public class BindableProxyFactory extends AbstractBindableProxyFactory
 				"'bindingTargetFactories' cannot be empty");
 	}
 
+	/**
+	 * Double-Checked Locking Optimization was used to avoid unnecessary locking overhead.
+	 */
 	@Override
-	public synchronized Object getObject() {
+	public Object getObject() {
 		if (this.proxy == null && this.type != null) {
-			ProxyFactory factory = new ProxyFactory(this.type, this);
-			this.proxy = factory.getProxy();
+			try {
+				this.lock.lock();
+				if (this.proxy == null && this.type != null) {
+					ProxyFactory factory = new ProxyFactory(this.type, this);
+					this.proxy = factory.getProxy();
+				}
+			}
+			finally {
+				this.lock.unlock();
+			}
 		}
 		return this.proxy;
 	}

core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binding/BindingService.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 the original author or authors.
+ * Copyright 2015-2024 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.
@@ -24,6 +24,7 @@ import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.locks.ReentrantLock;
 import java.util.stream.Stream;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -63,6 +64,7 @@ import org.springframework.validation.DataBinder;
  * @author Chris Bono
  * @author Artem Bilan
  * @author Byungjun You
+ * @author Omer Celik
  */
 public class BindingService {
 
@@ -451,35 +453,49 @@ public class BindingService {
 
 		private final String bindingName;
 
-		private final Object consumerOrProducerproperties;
+		private final Object consumerOrProducerProperties;
 
 		private final boolean isInput;
 
 		final ObjectMapper objectMapper;
 
-		LateBinding(String bindingName, String error, Object consumerOrProducerproperties, boolean isInput, ObjectMapper objectMapper) {
+		private final ReentrantLock lock = new ReentrantLock();
+
+		LateBinding(String bindingName, String error, Object consumerOrProducerProperties, boolean isInput, ObjectMapper objectMapper) {
 			super();
 			this.error = error;
 			this.bindingName = bindingName;
-			this.consumerOrProducerproperties = consumerOrProducerproperties;
+			this.consumerOrProducerProperties = consumerOrProducerProperties;
 			this.isInput = isInput;
 			this.objectMapper = objectMapper;
 		}
 
-		public synchronized void setDelegate(Binding<T> delegate) {
-			if (this.unbound) {
-				delegate.unbind();
+		public void setDelegate(Binding<T> delegate) {
+			try {
+				this.lock.lock();
+				if (this.unbound) {
+					delegate.unbind();
+				}
+				else {
+					this.delegate = delegate;
+				}
 			}
-			else {
-				this.delegate = delegate;
+			finally {
+				this.lock.unlock();
 			}
 		}
 
 		@Override
-		public synchronized void unbind() {
-			this.unbound = true;
-			if (this.delegate != null) {
-				this.delegate.unbind();
+		public void unbind() {
+			try {
+				this.lock.lock();
+				this.unbound = true;
+				if (this.delegate != null) {
+					this.delegate.unbind();
+				}
+			}
+			finally {
+				this.lock.unlock();
 			}
 		}
 
@@ -507,8 +523,8 @@ public class BindingService {
 		public Map<String, Object> getExtendedInfo() {
 			Map<String, Object> extendedInfo = new LinkedHashMap<>();
 			extendedInfo.put("bindingDestination", this.getBindingName());
-			extendedInfo.put(consumerOrProducerproperties.getClass().getSimpleName(),
-					this.objectMapper.convertValue(consumerOrProducerproperties, Map.class));
+			extendedInfo.put(consumerOrProducerProperties.getClass().getSimpleName(),
+					this.objectMapper.convertValue(consumerOrProducerProperties, Map.class));
 			return extendedInfo;
 		}
 

core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binding/DynamicDestinationsBindable.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2019 the original author or authors.
+ * Copyright 2016-2024 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 java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.springframework.cloud.stream.binder.Binding;
 
@@ -29,6 +30,7 @@ import org.springframework.cloud.stream.binder.Binding;
  *
  * @author Ilayaperumal Gopinathan
  * @author Oleg Zhurakousky
+ * @author Omer Celik
  */
 public final class DynamicDestinationsBindable implements Bindable {
 
@@ -37,21 +39,41 @@ public final class DynamicDestinationsBindable implements Bindable {
 	 */
 	private final Map<String, Binding<?>> outputBindings = new HashMap<>();
 
-	public synchronized void addOutputBinding(String name, Binding<?> binding) {
-		this.outputBindings.put(name, binding);
-	}
+	private static final ReentrantLock outputBindingsLock = new ReentrantLock();
 
-	@Override
-	public synchronized Set<String> getOutputs() {
-		return Collections.unmodifiableSet(this.outputBindings.keySet());
-	}
-
-	@Override
-	public synchronized void unbindOutputs(BindingService adapter) {
-		for (Map.Entry<String, Binding<?>> entry : this.outputBindings.entrySet()) {
-			entry.getValue().unbind();
+	public void addOutputBinding(String name, Binding<?> binding) {
+		try {
+			outputBindingsLock.lock();
+			this.outputBindings.put(name, binding);
+		}
+		finally {
+			outputBindingsLock.unlock();
+		}
+	}
+
+	@Override
+	public Set<String> getOutputs() {
+		try {
+			outputBindingsLock.lock();
+			return Collections.unmodifiableSet(this.outputBindings.keySet());
+		}
+		finally {
+			outputBindingsLock.unlock();
+		}
+	}
+
+	@Override
+	public void unbindOutputs(BindingService adapter) {
+		try {
+			outputBindingsLock.lock();
+			for (Map.Entry<String, Binding<?>> entry : this.outputBindings.entrySet()) {
+				entry.getValue().unbind();
+			}
+			this.outputBindings.clear();
+		}
+		finally {
+			outputBindingsLock.unlock();
 		}
-		this.outputBindings.clear();
 	}
 
 }