Merge branch '5.3.x'

spring-context/src/test/java/org/springframework/scheduling/concurrent/ThreadPoolExecutorFactoryBeanTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -16,8 +16,12 @@
 
 package org.springframework.scheduling.concurrent;
 
+import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.FutureTask;
+import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.ThreadPoolExecutor;
 
 import org.junit.jupiter.api.Test;
 
@@ -25,10 +29,16 @@ import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.support.GenericApplicationContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
 
 /**
+ * Tests for {@link ThreadPoolExecutorFactoryBean}.
+ *
  * @author Juergen Hoeller
  */
 class ThreadPoolExecutorFactoryBeanTests {
@@ -44,6 +54,27 @@ class ThreadPoolExecutorFactoryBeanTests {
 		context.close();
 	}
 
+	@Test
+	void executorWithDefaultSettingsDoesNotPrestartAllCoreThreads() {
+		GenericApplicationContext context = new GenericApplicationContext();
+		context.registerBean("taskExecutor", ThreadPoolExecutorFactoryBean.class, TestThreadPoolExecutorFactoryBean::new);
+		context.refresh();
+		ThreadPoolExecutor threadPoolExecutor = context.getBean(ThreadPoolExecutor.class);
+		verify(threadPoolExecutor, never()).prestartAllCoreThreads();
+	}
+
+	@Test
+	void executorWithPrestartAllCoreThreads() {
+		GenericApplicationContext context = new GenericApplicationContext();
+		context.registerBean("taskExecutor", ThreadPoolExecutorFactoryBean.class, () -> {
+			TestThreadPoolExecutorFactoryBean factoryBean = new TestThreadPoolExecutorFactoryBean();
+			factoryBean.setPrestartAllCoreThreads(true);
+			return factoryBean;
+		});
+		context.refresh();
+		ThreadPoolExecutor threadPoolExecutor = context.getBean(ThreadPoolExecutor.class);
+		verify(threadPoolExecutor).prestartAllCoreThreads();
+	}
 
 	@Configuration
 	static class ExecutorConfig {
@@ -55,4 +86,15 @@ class ThreadPoolExecutorFactoryBeanTests {
 
 	}
 
+	private static class TestThreadPoolExecutorFactoryBean extends ThreadPoolExecutorFactoryBean {
+
+		@Override
+		protected ThreadPoolExecutor createExecutor(
+				int corePoolSize, int maxPoolSize, int keepAliveSeconds, BlockingQueue<Runnable> queue,
+				ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler) {
+
+			return mock(ThreadPoolExecutor.class);
+		}
+	}
+
 }