Java 如何控制ParallelSuite线程数？

我有以下代码：

@RunWith(ParallelSuite.class)
@Suite.SuiteClasses({Test1.class,
        Test2.class,
        Test3.class,
        Test4.class,
        Test5.class,
        Test6.class,
        Test7.class})
public class ParallelRunner {
}

我运行了它，发现只有3个测试并行运行。这些测试持续了15秒以上

是操作系统调度程序问题还是junit线程池限制

---

如何配置线程池限制？

它由一个

ForkedThreadPool

支持，这是工作窃取

static ForkJoinPool setUpForkJoinPool() {
    int numThreads;
    try {
        String configuredNumThreads = System.getProperty("maxParallelTestThreads");
        numThreads = Math.max(2, Integer.parseInt(configuredNumThreads));
    } catch (Exception ignored) {
        Runtime runtime = Runtime.getRuntime();
        numThreads = Math.max(2, runtime.availableProcessors());
    }
    ForkJoinPool.ForkJoinWorkerThreadFactory threadFactory = pool -> {
        if (pool.getPoolSize() >= pool.getParallelism()) {
            return null;
        } else {
            ForkJoinWorkerThread thread = ForkJoinPool.defaultForkJoinWorkerThreadFactory.newThread(pool);
            thread.setName("JUnit-" + thread.getName());
            return thread;
        }
    };
    return new ForkJoinPool(numThreads, threadFactory, null, false);
}

---

可以有效地设置

maxParallelTestThreads

，否则它将返回到处理器数量的最大值，或至少两个线程。

在

ParallelComputer

内部，您可以找到以下方法：

private static Runner parallelize(Runner runner) {
        if (runner instanceof ParentRunner) {
            ((ParentRunner)runner).setScheduler(new RunnerScheduler() {
                private final ExecutorService fService = Executors.newCachedThreadPool();

                public void schedule(Runnable childStatement) {
                    this.fService.submit(childStatement);
                }

                public void finished() {
                    try {
                        this.fService.shutdown();
                        this.fService.awaitTermination(9223372036854775807L, TimeUnit.NANOSECONDS);
                    } catch (InterruptedException var2) {
                        var2.printStackTrace(System.err);
                    }

                }
            });
        }

        return runner;
    }

我们需要替换这个：

private final ExecutorService fService = Executors.newCachedThreadPool();

我只是复制粘贴的

ParallelComputer

类代码，并将此行替换为：

private final ExecutorService fService = Executors.newFixedThreadPool(MAX_THREAD_COUNT);

---

1.我可以在哪里配置它？2.它是默认的jvm forkJoin线程池吗？粘贴的代码来自

ParallelSuite

，如果要配置它，您需要通过

maxParallelTestThreads

，或者在测试中手动设置它。否则它将是maxNumberOfCores或2个更高的值。