java - 如何编写并发单元测试

Question

Awaitility是对并发生产代码进行单元测试的好工具。

问题:是否有一种工具可以简化并发测试代码的编写？

假设我想测试 java.util.concurrent.LinkedBlockingQueue。

public class BlockingQueueTest {
    private LinkedBlockingQueue<String> out;

    @Before
    public void setUp() {
        out = new LinkedBlockingQueue<>();
    }

    @Test
    public void putThenGet() throws InterruptedException {
        // that's easy because it can be done in one thread
        out.put("Hello");

        String taken = out.take();

        assertThat(taken).isEqualTo("Hello");
    }

    @Test
    public void getBeforePut() throws InterruptedException {
        // that's more tricky because it can't be done with one thread
        ExecutorService executorService = Executors.newSingleThreadExecutor();
        executorService.submit(() -> {
            Thread.sleep(100);
            out.put("Hello");
            return null;
        });
        executorService.shutdown();

        String taken = out.take();

        assertThat(taken).isEqualTo("Hello");
    }
}

getBeforePut() 编写代码并不有趣。有没有办法让它变得不那么困难和更具可读性，就像这样？

@Test
public void getBeforePut2() throws InterruptedException {
    // Wanted: DSL for concurrent test-code
    Concurrently.sleep(100, TimeUnit.MILLISECONDS).andThen(() -> out.put("Hello"));

    String taken = out.take();

    assertThat(taken).isEqualTo("Hello");
}

Answer 1

使用 TestNG对我来说是最简单的方法:

 @Test(threadPoolSize = 10, invocationCount = 15, timeOut = 1000)
 public void testPut(){
     out.put("Hello");
 }

此测试将在 10 个线程中运行 15 次，并且应该不会超过 1000 毫秒。

您还可以创建依赖于其他测试的测试

@Test(dependsOnMethods = "testPut")
public void testGetAfterPut{
    String taken = out.take();

    assertThat(taken).isEqualTo("Hello");
}