Java 如何测试原子性布尔原子性？

我正在为AtomicInteger和AtomicBoolean编写单元测试。它们将被用作在objective-c中测试这些类的模拟的参考测试，用于翻译项目

我认为AtomicInteger测试运行得很好，基本上是通过在大量for循环中执行可预测数量的递增、递减、加法和减法操作，每个循环在各自的线程中运行（每个操作类型有许多线程）。实际操作使用倒计时锁存器同时开始

当所有线程都完成时，我通过比较原子整数和基于线程数、每个线程的迭代次数以及每次迭代的预期增加/减少的预期整数值来断言。这个测试通过了

但是如何测试AtomicBoolean呢？基本操作是get和set，因此在多个线程中多次调用并期望最终结果为true或false似乎没有意义。我想的方向是使用两个原子布尔，它们的值应该总是相反的。像这样：

@Test
public void testAtomicity() throws Exception {

    // ====  SETUP  ====
    final AtomicBoolean booleanA = new AtomicBoolean(true);
    final AtomicBoolean booleanB = new AtomicBoolean(false);

    final int threadCount = 50;

    final int iterationsPerThread = 5000;

    final CountDownLatch startSignalLatch = new CountDownLatch(1);
    final CountDownLatch threadsFinishedLatch = new CountDownLatch(threadCount);

    final AtomicBoolean assertFailed = new AtomicBoolean(false);

    // ====  EXECUTE: start all threads ====
    for (int i = 0; i < threadCount; i++) {

        // ====  Create the thread  =====
        AtomicOperationsThread thread;
        thread = new AtomicOperationsThread("Thread #" + i, booleanA, booleanB, startSignalLatch, threadsFinishedLatch, iterationsPerThread, assertFailed);
        System.out.println("Creating Thread #" + i);

        // ====  Start the thread (each thread will wait until the startSignalLatch is triggered)  =====
        thread.start();
    }

    startSignalLatch.countDown();

    // ====  VERIFY: that the AtomicInteger has the expected value after all threads have finished  ====
    final boolean allThreadsFinished;
    allThreadsFinished = threadsFinishedLatch.await(60, TimeUnit.SECONDS);

    assertTrue("Not all threads have finished before reaching the timeout", allThreadsFinished);
    assertFalse(assertFailed.get());

}

private static class AtomicOperationsThread extends Thread {

    // #####  Instance variables  #####

    private final CountDownLatch startSignalLatch;
    private final CountDownLatch threadsFinishedLatch;

    private final int iterations;

    private final AtomicBoolean booleanA, booleanB;

    private final AtomicBoolean assertFailed;

    // #####  Constructor  #####

    private AtomicOperationsThread(final String name, final AtomicBoolean booleanA, final AtomicBoolean booleanB, final CountDownLatch startSignalLatch, final CountDownLatch threadsFinishedLatch, final int iterations, final AtomicBoolean assertFailed) {

        super(name);
        this.booleanA = booleanA;
        this.booleanB = booleanB;
        this.startSignalLatch = startSignalLatch;
        this.threadsFinishedLatch = threadsFinishedLatch;
        this.iterations = iterations;
        this.assertFailed = assertFailed;
    }

    // #####  Thread implementation  #####

    @Override
    public void run() {

        super.run();

        // ====  Wait for the signal to start (so all threads are executed simultaneously)  =====
        try {
            System.out.println(this.getName() + " has started. Awaiting startSignal.");
            startSignalLatch.await();  /* Awaiting start signal */
        } catch (InterruptedException e) {
            throw new RuntimeException("The startSignalLatch got interrupted.", e);
        }

        // ====  Perform the atomic operations  =====
        for (int i = 0; i < iterations; i++) {

            final boolean booleanAChanged;
            booleanAChanged = booleanA.compareAndSet(!booleanB.get(), booleanB.getAndSet(booleanA.get()));  /* Set A to the current value of B if A is currently the opposite of B, then set B to the current value of A */

            if (!booleanAChanged){
                assertFailed.set(true);
                System.out.println("Assert failed in thread: " + this.getName());
            }
        }

        // ====  Mark this thread as finished  =====
        threadsFinishedLatch.countDown();
    }
}

@测试
public void testAtomicity（）引发异常{
//==设置====
最终原子布尔布尔A=新原子布尔（真）；
最终原子布尔布尔B=新原子布尔（假）；
最终int螺纹数=50；
最终int迭代perthread=5000；
最终倒计时闩锁启动信号拉奇=新倒计时闩锁（1）；
最终倒计时闩锁螺纹FinishedLatch=新倒计时闩锁（螺纹计数）；
最终AtomicBoolean assertFailed=新的AtomicBoolean（false）；
//==执行：启动所有线程====
对于（int i=0；i

这可以在一个线程中工作，但在多个线程中失败。我猜这是因为

booleanAChanged=booleanA.compareAndSet（！booleanB.get（），booleanB.getAndSet（booleanA.get（））不是一个原子操作

有什么建议吗？
这是四个原子操作。如果你只想让一个布尔值成为另一个布尔值的倒数，只要有一个布尔值并不断切换即可。您可以从该值计算另一个。
我将集中讨论
比较数据集
，这是
原子布尔
和普通
布尔
之间的真正区别

例如，使用
compareAndSet（false，true）
控制关键区域。循环执行，直到返回false，然后输入临界区域。在关键区域，如果两个或多个线程同时运行，则执行一些很可能失败的操作。例如，在读取旧值和写入新值之间的短睡眠时间内递增计数器。在关键区域的末尾，将
AtomicBoolean
设置为false

在启动线程之前，将
AtomicBoolean
初始化为false，并将
globalCounter
初始化为零

for(int i=0; i<iterations; i++) {
  while (!AtomicBooleanTest.atomic.compareAndSet(false, true));
  int oldValue = AtomicBooleanTest.globalCounter;
  Thread.sleep(1);
  AtomicBooleanTest.globalCounter = oldValue + 1;
  AtomicBooleanTest.atomic.set(false);
}

for（int i=0；i正如您所指出的，我认为测试这一点要比测试一个
AtomicInteger
困难。可能值的空间要小得多，因此可能出错的事情的空间也要小得多