Mark bootstrap thread for entire finishBeanFactoryInitialization phase

Closes gh-35398

spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -936,6 +936,9 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	 */
 	@SuppressWarnings("unchecked")
 	protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) {
+		// Mark current thread for singleton instantiation with applied bootstrap locking.
+		beanFactory.prepareSingletonBootstrap();
+
 		// Initialize bootstrap executor for this context.
 		if (beanFactory.containsBean(BOOTSTRAP_EXECUTOR_BEAN_NAME) &&
 				beanFactory.isTypeMatch(BOOTSTRAP_EXECUTOR_BEAN_NAME, Executor.class)) {

spring-context/src/test/java/org/springframework/context/annotation/BackgroundBootstrapTests.java

@@ -31,6 +31,7 @@ import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.testfixture.beans.TestBean;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.weaving.LoadTimeWeaverAware;
 import org.springframework.core.SpringProperties;
 import org.springframework.core.testfixture.EnabledForTestGroups;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
@@ -68,6 +69,16 @@ class BackgroundBootstrapTests {
 		ctx.close();
 	}
 
+	@Test
+	@Timeout(10)
+	@EnabledForTestGroups(LONG_RUNNING)
+	void bootstrapWithLoadTimeWeaverAware() {
+		ConfigurableApplicationContext ctx = new AnnotationConfigApplicationContext(LoadTimeWeaverAwareBeanConfig.class);
+		ctx.getBean("testBean1", TestBean.class);
+		ctx.getBean("testBean2", TestBean.class);
+		ctx.close();
+	}
+
 	@Test
 	@Timeout(10)
 	@EnabledForTestGroups(LONG_RUNNING)
@@ -266,6 +277,50 @@ class BackgroundBootstrapTests {
 	}
 
 
+	@Configuration(proxyBeanMethods = false)
+	static class LoadTimeWeaverAwareBeanConfig {
+
+		@Bean
+		LoadTimeWeaverAware loadTimeWeaverAware(ObjectProvider<TestBean> testBean1) {
+			Thread thread = new Thread(testBean1::getObject);
+			thread.start();
+			try {
+				thread.join();
+			}
+			catch (InterruptedException ex) {
+				Thread.currentThread().interrupt();
+			}
+			return (loadTimeWeaver -> {});
+		}
+
+		@Bean
+		public TestBean testBean1(TestBean testBean2) {
+			return new TestBean(testBean2);
+		}
+
+		@Bean @Lazy
+		public FactoryBean<TestBean> testBean2() {
+			try {
+				Thread.sleep(2000);
+			}
+			catch (InterruptedException ex) {
+				Thread.currentThread().interrupt();
+			}
+			TestBean testBean = new TestBean();
+			return new FactoryBean<>() {
+				@Override
+				public TestBean getObject() {
+					return testBean;
+				}
+				@Override
+				public Class<?> getObjectType() {
+					return testBean.getClass();
+				}
+			};
+		}
+	}
+
+
 	@Configuration(proxyBeanMethods = false)
 	static class StrictLockingBeanConfig {