Initialize PostgreSQL SharedTimer on JUnit launcher thread

spring-test/src/main/java/org/springframework/test/context/jdbc/PostgresqlSharedTimerLauncherSessionListener.java

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+/*
+ * Copyright 2002-present 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.test.context.jdbc;
+
+import java.lang.reflect.Method;
+
+import org.jspecify.annotations.Nullable;
+
+import org.junit.platform.launcher.LauncherSession;
+import org.junit.platform.launcher.LauncherSessionListener;
+
+import org.springframework.util.ClassUtils;
+import org.springframework.util.ReflectionUtils;
+
+/**
+ * {@link LauncherSessionListener} that eagerly initializes the PostgreSQL JDBC driver's
+ * shared {@link java.util.Timer} on the JUnit launcher thread.
+ * <p>This prevents the driver's {@code TimerThread} from inheriting Spring's
+ * {@code TransactionContextHolder} from a transactional test thread, which would otherwise
+ * pin an {@code ApplicationContext} for the lifetime of the JVM.
+ *
+ * @since 7.0.x
+ * @see <a href="https://github.com/spring-projects/spring-framework/issues/36737">gh-36737</a>
+ */
+public final class PostgresqlSharedTimerLauncherSessionListener implements LauncherSessionListener {
+
+	private static final String POSTGRESQL_DRIVER_CLASS_NAME = "org.postgresql.Driver";
+
+
+	@Override
+	public void launcherSessionOpened(LauncherSession session) {
+		initializeSharedTimer();
+	}
+
+	private static void initializeSharedTimer() {
+		try {
+			Class<?> driverClass = ClassUtils.forName(POSTGRESQL_DRIVER_CLASS_NAME, null);
+			Method getSharedTimer = ClassUtils.getMethodIfAvailable(driverClass, "getSharedTimer");
+			if (getSharedTimer == null) {
+				return;
+			}
+			@Nullable Object sharedTimer = ReflectionUtils.invokeMethod(getSharedTimer, null);
+			if (sharedTimer == null) {
+				return;
+			}
+			Method getTimer = ClassUtils.getMethodIfAvailable(sharedTimer.getClass(), "getTimer");
+			if (getTimer != null) {
+				ReflectionUtils.invokeMethod(getTimer, sharedTimer);
+			}
+		}
+		catch (ClassNotFoundException | LinkageError ex) {
+			// PostgreSQL JDBC driver not present
+		}
+	}
+
+}

spring-test/src/main/resources/META-INF/services/org.junit.platform.launcher.LauncherSessionListener

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+org.springframework.test.context.jdbc.PostgresqlSharedTimerLauncherSessionListener

spring-test/src/test/java/org/springframework/test/context/jdbc/PostgresqlSharedTimerLauncherSessionListenerTests.java

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+/*
+ * Copyright 2002-present 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.test.context.jdbc;
+
+import org.junit.jupiter.api.Test;
+import org.junit.platform.launcher.LauncherSession;
+
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link PostgresqlSharedTimerLauncherSessionListener}.
+ */
+class PostgresqlSharedTimerLauncherSessionListenerTests {
+
+	@Test
+	void launcherSessionOpenedDoesNotThrowWhenPostgresqlDriverIsAbsent() {
+		PostgresqlSharedTimerLauncherSessionListener listener =
+				new PostgresqlSharedTimerLauncherSessionListener();
+		listener.launcherSessionOpened(mock(LauncherSession.class));
+	}
+
+}