GH-9291: Enhanced unlock() method of JdbcLock to verify successful unlocking

spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/lock/DefaultLockRepository.java

@@ -62,6 +62,7 @@
  * @author Gary Russell
  * @author Alexandre Strubel
  * @author Ruslan Stelmachenko
+ * @author Eddie Cho
  *
  * @since 4.3
  */
@@ -389,9 +390,9 @@ public void close() {
 	}
 
 	@Override
-	public void delete(String lock) {
-		this.defaultTransactionTemplate.executeWithoutResult(
-				transactionStatus -> this.template.update(this.deleteQuery, this.region, lock, this.id));
+	public boolean delete(String lock) {
+		return this.defaultTransactionTemplate.execute(
+				transactionStatus -> this.template.update(this.deleteQuery, this.region, lock, this.id)) > 0;
 	}
 
 	@Override

spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/lock/JdbcLockRegistry.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2023 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.
@@ -17,6 +17,7 @@
 package org.springframework.integration.jdbc.lock;
 
 import java.time.Duration;
+import java.util.ConcurrentModificationException;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -56,6 +57,7 @@
  * @author Unseok Kim
  * @author Christian Tzolov
  * @author Myeonghyeon Lee
+ * @author Eddie Cho
  *
  * @since 4.3
  */
@@ -305,12 +307,20 @@ public void unlock() {
 			try {
 				while (true) {
 					try {
-						this.mutex.delete(this.path);
-						return;
+						if (this.mutex.delete(this.path)) {
+							return;
+						}
+						else {
+							throw new ConcurrentModificationException("Lock was released in the store due to expiration. " +
+									"The integrity of data protected by this lock may have been compromised.");
+						}
 					}
 					catch (TransientDataAccessException | TransactionTimedOutException | TransactionSystemException e) {
 						// try again
 					}
+					catch (ConcurrentModificationException e) {
+						throw e;
+					}
 					catch (Exception e) {
 						throw new DataAccessResourceFailureException("Failed to release mutex at " + this.path, e);
 					}

spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/lock/LockRepository.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 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.
@@ -26,6 +26,7 @@
  * @author Dave Syer
  * @author Alexandre Strubel
  * @author Artem Bilan
+ * @author Eddie Cho
  *
  * @since 4.3
  */
@@ -41,8 +42,9 @@ public interface LockRepository extends Closeable {
 	/**
 	 * Remove a lock from this repository.
 	 * @param lock the lock to remove.
+	 * @return deleted or not.
 	 */
-	void delete(String lock);
+	boolean delete(String lock);
 
 	/**
 	 * Remove all the expired locks.

spring-integration-jdbc/src/test/java/org/springframework/integration/jdbc/lock/JdbcLockRegistryDelegateTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2022 the original author or authors.
+ * Copyright 2020-2024 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.
@@ -17,7 +17,6 @@
 package org.springframework.integration.jdbc.lock;
 
 import java.util.Random;
-import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
@@ -31,17 +30,17 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 /**
  * @author Olivier Hubaut
  * @author Fran Aranda
+ * @author Eddie Cho
  *
  * @since 5.2.11
  */
-public class JdbcLockRegistryDelegateTests {
+class JdbcLockRegistryDelegateTests {
 
 	private JdbcLockRegistry registry;
 
@@ -56,7 +55,7 @@ public void clear() {
 	}
 
 	@Test
-	public void testLessAmountOfUnlockThanLock() {
+	void testLessAmountOfUnlockThanLock() {
 		final Random random = new Random();
 		final int lockCount = random.nextInt(5) + 1;
 		final int unlockCount = random.nextInt(lockCount);
@@ -73,11 +72,13 @@ public void testLessAmountOfUnlockThanLock() {
 	}
 
 	@Test
-	public void testSameAmountOfUnlockThanLock() {
+	void testSameAmountOfUnlockThanLock() {
 		final Random random = new Random();
 		final int lockCount = random.nextInt(5) + 1;
 
 		final Lock lock = registry.obtain("foo");
+		when(repository.delete(anyString())).thenReturn(true);
+
 		for (int i = 0; i < lockCount; i++) {
 			lock.tryLock();
 		}
@@ -89,53 +90,41 @@ public void testSameAmountOfUnlockThanLock() {
 	}
 
 	@Test
-	public void testTransientDataAccessException() {
+	void testTransientDataAccessException() {
 		final Lock lock = registry.obtain("foo");
 		lock.tryLock();
 
-		final AtomicBoolean shouldThrow = new AtomicBoolean(true);
-		doAnswer(invocation -> {
-			if (shouldThrow.getAndSet(false)) {
-				throw mock(TransientDataAccessException.class);
-			}
-			return null;
-		}).when(repository).delete(anyString());
+		when(repository.delete(anyString()))
+				.thenThrow(mock(TransientDataAccessException.class))
+				.thenReturn(true);
 
 		lock.unlock();
 
 		assertThat(TestUtils.getPropertyValue(lock, "delegate", ReentrantLock.class).isLocked()).isFalse();
 	}
 
 	@Test
-	public void testTransactionTimedOutException() {
+	void testTransactionTimedOutException() {
 		final Lock lock = registry.obtain("foo");
 		lock.tryLock();
 
-		final AtomicBoolean shouldThrow = new AtomicBoolean(true);
-		doAnswer(invocation -> {
-			if (shouldThrow.getAndSet(false)) {
-				throw mock(TransactionTimedOutException.class);
-			}
-			return null;
-		}).when(repository).delete(anyString());
+		when(repository.delete(anyString()))
+				.thenThrow(TransactionTimedOutException.class)
+				.thenReturn(true);
 
 		lock.unlock();
 
 		assertThat(TestUtils.getPropertyValue(lock, "delegate", ReentrantLock.class).isLocked()).isFalse();
 	}
 
 	@Test
-	public void testTransactionSystemException() {
+	void testTransactionSystemException() {
 		final Lock lock = registry.obtain("foo");
 		lock.tryLock();
 
-		final AtomicBoolean shouldThrow = new AtomicBoolean(true);
-		doAnswer(invocation -> {
-			if (shouldThrow.getAndSet(false)) {
-				throw mock(TransactionSystemException.class);
-			}
-			return null;
-		}).when(repository).delete(anyString());
+		when(repository.delete(anyString()))
+				.thenThrow(TransactionSystemException.class)
+				.thenReturn(true);
 
 		lock.unlock();
 

spring-integration-jdbc/src/test/java/org/springframework/integration/jdbc/lock/JdbcLockRegistryDifferentClientTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2022 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.
@@ -17,6 +17,7 @@
 package org.springframework.integration.jdbc.lock;
 
 import java.util.ArrayList;
+import java.util.ConcurrentModificationException;
 import java.util.List;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.Callable;
@@ -45,18 +46,20 @@
 import org.springframework.util.StopWatch;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 /**
  * @author Dave Syer
  * @author Artem Bilan
  * @author Glenn Renfro
  * @author Alexandre Strubel
+ * @author Eddie Cho
  *
  * @since 4.3
  */
 @SpringJUnitConfig(locations = "JdbcLockRegistryTests-context.xml")
 @DirtiesContext
-public class JdbcLockRegistryDifferentClientTests {
+class JdbcLockRegistryDifferentClientTests {
 
 	private static final Log LOGGER = LogFactory.getLog(JdbcLockRegistryDifferentClientTests.class);
 
@@ -92,7 +95,7 @@ public void close() {
 	}
 
 	@Test
-	public void testSecondThreadLoses() throws Exception {
+	void testSecondThreadLoses() throws Exception {
 		for (int i = 0; i < 100; i++) {
 			final JdbcLockRegistry registry1 = this.registry;
 			final JdbcLockRegistry registry2 = this.child.getBean(JdbcLockRegistry.class);
@@ -129,7 +132,7 @@ public void testSecondThreadLoses() throws Exception {
 	}
 
 	@Test
-	public void testBothLock() throws Exception {
+	void testBothLock() throws Exception {
 		for (int i = 0; i < 100; i++) {
 			final JdbcLockRegistry registry1 = this.registry;
 			final JdbcLockRegistry registry2 = this.child.getBean(JdbcLockRegistry.class);
@@ -185,7 +188,7 @@ public void testBothLock() throws Exception {
 	}
 
 	@Test
-	public void testOnlyOneLock() throws Exception {
+	void testOnlyOneLock() throws Exception {
 		for (int i = 0; i < 100; i++) {
 			final BlockingQueue<String> locked = new LinkedBlockingQueue<>();
 			final CountDownLatch latch = new CountDownLatch(20);
@@ -231,7 +234,7 @@ public void testOnlyOneLock() throws Exception {
 	}
 
 	@Test
-	public void testExclusiveAccess() throws Exception {
+	void testExclusiveAccess() throws Exception {
 		DefaultLockRepository client1 = new DefaultLockRepository(dataSource);
 		client1.setApplicationContext(this.context);
 		client1.afterPropertiesSet();
@@ -281,7 +284,7 @@ public void testExclusiveAccess() throws Exception {
 	}
 
 	@Test
-	public void testOutOfDateLockTaken() throws Exception {
+	void testOutOfDateLockTaken() throws Exception {
 		DefaultLockRepository client1 = new DefaultLockRepository(dataSource);
 		client1.setTimeToLive(100);
 		client1.setApplicationContext(this.context);
@@ -314,7 +317,7 @@ public void testOutOfDateLockTaken() throws Exception {
 				});
 		assertThat(latch.await(10, TimeUnit.SECONDS)).isTrue();
 		data.add(2);
-		lock1.unlock();
+		assertThatThrownBy(lock1::unlock).isInstanceOf(ConcurrentModificationException.class);
 		for (int i = 0; i < 2; i++) {
 			Integer integer = data.poll(10, TimeUnit.SECONDS);
 			assertThat(integer).isNotNull();
@@ -323,7 +326,7 @@ public void testOutOfDateLockTaken() throws Exception {
 	}
 
 	@Test
-	public void testRenewLock() throws Exception {
+	void testRenewLock() throws Exception {
 		DefaultLockRepository client1 = new DefaultLockRepository(dataSource);
 		client1.setTimeToLive(500);
 		client1.setApplicationContext(this.context);