BAEL-3817 - Add unit tests showing the difference between the Spring ThreadPoolTaskExecutor's corePoolSize and maxPoolSize properties

2020-02-08 04:51:16 -06:00
parent 5d8f71a8bc
commit df31ae0b5e
4 changed files with 181 additions and 0 deletions
--- a/spring-threads/src/test/java/com/baeldung/threading/ThreadPoolTaskExecutorUnitTest.java
+++ b/spring-threads/src/test/java/com/baeldung/threading/ThreadPoolTaskExecutorUnitTest.java
@@ -0,0 +1,130 @@
+package com.baeldung.threading;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ThreadLocalRandom;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+
+public class ThreadPoolTaskExecutorUnitTest {
+
+    @Test
+    public void whenUsingDefaults_thenSingleThread() {
+        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
+        taskExecutor.afterPropertiesSet();
+
+        CountDownLatch countDownLatch = new CountDownLatch(10);
+        for (int i = 0; i < 10; i++) {
+            taskExecutor.execute(() -> {
+                try {
+                    Thread.sleep(10L * ThreadLocalRandom.current().nextLong(1, 10));
+                    countDownLatch.countDown();
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            });
+        }
+
+        while (countDownLatch.getCount() > 0) {
+            Assert.assertEquals(1, taskExecutor.getPoolSize());
+        }
+    }
+
+    @Test
+    public void whenCorePoolSizeFive_thenFiveThreads() {
+        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
+        taskExecutor.setCorePoolSize(5);
+        taskExecutor.afterPropertiesSet();
+
+        CountDownLatch countDownLatch = new CountDownLatch(10);
+        for (int i = 0; i < 10; i++) {
+            taskExecutor.execute(() -> {
+                try {
+                    Thread.sleep(100L * ThreadLocalRandom.current().nextLong(1, 10));
+                    countDownLatch.countDown();
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            });
+        }
+
+        while (countDownLatch.getCount() > 0) {
+            Assert.assertEquals(5, taskExecutor.getPoolSize());
+        }
+    }
+
+    @Test
+    public void whenCorePoolSizeFive_andMaxPoolSizeTen_thenFiveThreads() {
+        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
+        taskExecutor.setCorePoolSize(5);
+        taskExecutor.setMaxPoolSize(10);
+        taskExecutor.afterPropertiesSet();
+
+        CountDownLatch countDownLatch = new CountDownLatch(10);
+        for (int i = 0; i < 10; i++) {
+            taskExecutor.execute(() -> {
+                try {
+                    Thread.sleep(100L * ThreadLocalRandom.current().nextLong(1, 10));
+                    countDownLatch.countDown();
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            });
+        }
+
+        while (countDownLatch.getCount() > 0) {
+            Assert.assertEquals(5, taskExecutor.getPoolSize());
+        }
+    }
+
+    @Test
+    public void whenCorePoolSizeFive_andMaxPoolSizeTen_andQueueCapacityZero_thenTenThreads() {
+        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
+        taskExecutor.setCorePoolSize(5);
+        taskExecutor.setMaxPoolSize(10);
+        taskExecutor.setQueueCapacity(0);
+        taskExecutor.afterPropertiesSet();
+
+        CountDownLatch countDownLatch = new CountDownLatch(10);
+        for (int i = 0; i < 10; i++) {
+            taskExecutor.execute(() -> {
+                try {
+                    Thread.sleep(100L * ThreadLocalRandom.current().nextLong(1, 10));
+                    countDownLatch.countDown();
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            });
+        }
+
+        while (countDownLatch.getCount() > 0) {
+            Assert.assertEquals(10, taskExecutor.getPoolSize());
+        }
+    }
+
+    @Test
+    public void whenCorePoolSizeFive_andMaxPoolSizeTen_andQueueCapacityTen_thenTenThreads() {
+        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
+        taskExecutor.setCorePoolSize(5);
+        taskExecutor.setMaxPoolSize(10);
+        taskExecutor.setQueueCapacity(10);
+        taskExecutor.afterPropertiesSet();
+
+        CountDownLatch countDownLatch = new CountDownLatch(10);
+        for (int i = 0; i < 20; i++) {
+            taskExecutor.execute(() -> {
+                try {
+                    Thread.sleep(100L * ThreadLocalRandom.current().nextLong(1, 10));
+                    countDownLatch.countDown();
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            });
+        }
+
+        while (countDownLatch.getCount() > 0) {
+            Assert.assertEquals(10, taskExecutor.getPoolSize());
+        }
+    }
+}