}

    @Test
    public void testThreadSafety() throws InterruptedException {
        // Test concurrent updates from multiple threads
        Thread[] threads = new Thread[10];

        for (int i = 0; i < threads.length; i++) {
            final int index = i;
            threads[i] = new Thread(() -> {
                for (int j = 0; j < 100; j++) {
                    String name = "file" + index + "_" + j + ".txt";

  class Interruptenator extends Thread {
    final AtomicBoolean shutdown;

    Interruptenator(Thread interruptee) {
      this(interruptee, new AtomicBoolean(false));
    }

    @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
    Interruptenator(Thread interruptee, AtomicBoolean shutdown) {
      super(
          new Runnable() {

        // Test thread safety with concurrent operations
        final int threadCount = 10;
        Thread[] threads = new Thread[threadCount];
        final boolean[] results = new boolean[threadCount];

        for (int i = 0; i < threadCount; i++) {
            final int index = i;
            threads[i] = new Thread(() -> {
                String thumbnailId = "concurrent-" + index;

    assertThat(Thread.interrupted()).isTrue();
  }

  public void testInterrupt_doesNotInterruptSubsequentTask() throws Exception {
    // Run a task that interrupts its thread (i.e. this thread).
    e.execute(
        new Runnable() {
          @Override
          public void run() {
            Thread.currentThread().interrupt();
          }
        });

        // Test thread safety
        final int threadCount = 10;
        final int docsPerThread = 10;
        final List<Thread> threads = new ArrayList<>();
        final AtomicInteger successCount = new AtomicInteger(0);

        for (int i = 0; i < threadCount; i++) {
            final int threadId = i;
            Thread thread = new Thread(() -> {

    assertFalse(future.isDone());
    assertFalse(future.isCancelled());

    CountDownLatch successLatch = new CountDownLatch(1);

    // Run cancellation in a separate thread as an extra thread-safety test.
    new Thread(
            () -> {
              assertThrows(CancellationException.class, future::get);
              successLatch.countDown();
            })
        .start();

                            session.acquire();
                            Thread.yield(); // Increase chance of race conditions
                            session.release();
                        } else {
                            session.acquire();
                            // Hold for a bit
                            Thread.sleep(1);
                            session.release();
                        }

        // Test thread safety - multiple threads accessing the same response
        final int THREAD_COUNT = 10;
        Thread[] threads = new Thread[THREAD_COUNT];
        final boolean[] success = new boolean[THREAD_COUNT];

        for (int i = 0; i < THREAD_COUNT; i++) {
            final int index = i;
            threads[i] = new Thread(() -> {
                try {

            // Start all threads
            for (Thread thread : threads) {
                thread.start();
            }

            // Wait for all threads to complete
            for (Thread thread : threads) {
                try {
                    thread.join();
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                    fail("Thread interrupted");

      }
      return;
    }

    /*
     * This is an unsynchronized read! After the read, the function returns immediately or acquires
     * the lock to check again. Since an IDLE state was observed inside the preceding synchronized
     * block, and reference field assignment is atomic, this may save reacquiring the lock when
     * another thread or the worker task has cleared the count and set the state.
     *