Remove race condition in TaskSchedulingAutoConfigurationTests

Closes gh-16640

Author: wilkinsona

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/task/TaskSchedulingAutoConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2018 the original author or authors.
+ * Copyright 2012-2019 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.
@@ -18,8 +18,10 @@
 
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
 
 import org.junit.Test;
 
@@ -63,7 +65,7 @@ public void enableSchedulingWithNoTaskExecutorAutoConfiguresOne() {
 				.withUserConfiguration(SchedulingConfiguration.class).run((context) -> {
 					assertThat(context).hasSingleBean(TaskExecutor.class);
 					TestBean bean = context.getBean(TestBean.class);
-					Thread.sleep(15);
+					assertThat(bean.latch.await(30, TimeUnit.SECONDS)).isTrue();
 					assertThat(bean.threadNames)
 							.allMatch((name) -> name.contains("scheduling-test-"));
 				});
@@ -79,7 +81,7 @@ public void enableSchedulingWithNoTaskExecutorAppliesCustomizers() {
 				.run((context) -> {
 					assertThat(context).hasSingleBean(TaskExecutor.class);
 					TestBean bean = context.getBean(TestBean.class);
-					Thread.sleep(15);
+					assertThat(bean.latch.await(30, TimeUnit.SECONDS)).isTrue();
 					assertThat(bean.threadNames)
 							.allMatch((name) -> name.contains("customized-scheduler-"));
 				});
@@ -93,7 +95,7 @@ public void enableSchedulingWithExistingTaskSchedulerBacksOff() {
 					assertThat(context.getBean(TaskScheduler.class))
 							.isInstanceOf(TestTaskScheduler.class);
 					TestBean bean = context.getBean(TestBean.class);
-					Thread.sleep(15);
+					assertThat(bean.latch.await(30, TimeUnit.SECONDS)).isTrue();
 					assertThat(bean.threadNames).containsExactly("test-1");
 				});
 	}
@@ -105,7 +107,7 @@ public void enableSchedulingWithExistingScheduledExecutorServiceBacksOff() {
 					assertThat(context).doesNotHaveBean(TaskScheduler.class);
 					assertThat(context).hasSingleBean(ScheduledExecutorService.class);
 					TestBean bean = context.getBean(TestBean.class);
-					Thread.sleep(15);
+					assertThat(bean.latch.await(30, TimeUnit.SECONDS)).isTrue();
 					assertThat(bean.threadNames)
 							.allMatch((name) -> name.contains("pool-"));
 				});
@@ -117,7 +119,7 @@ public void enableSchedulingWithConfigurerBacksOff() {
 				SchedulingConfigurerConfiguration.class).run((context) -> {
 					assertThat(context).doesNotHaveBean(TaskScheduler.class);
 					TestBean bean = context.getBean(TestBean.class);
-					Thread.sleep(15);
+					assertThat(bean.latch.await(30, TimeUnit.SECONDS)).isTrue();
 					assertThat(bean.threadNames).containsExactly("test-1");
 				});
 	}
@@ -185,9 +187,12 @@ static class TestBean {
 
 		private final Set<String> threadNames = ConcurrentHashMap.newKeySet();
 
-		@Scheduled(fixedRate = 10)
+		private final CountDownLatch latch = new CountDownLatch(1);
+
+		@Scheduled(fixedRate = 60000)
 		public void accumulate() {
 			this.threadNames.add(Thread.currentThread().getName());
+			this.latch.countDown();
 		}
 
 	}